CMS PAPER CFT-09-025
CMS Paper
2010/01/11
Fine Synchronization of the CMS Muon Drift-Tube LocalTrigger using Cosmic Rays
The CMS Collaboration∗
Abstract
The CMS experiment uses self-triggering arrays of drift tubes in the barrel muon trig-ger to perform the identification of the correct bunch crossing. The identification isunique only if the trigger chain is correctly synchronized. In this paper, the synchro-nization performed during an extended cosmic ray run is described and the resultsare reported. The random arrival time of cosmic ray muons allowed several synchro-nization aspects to be studied and a simple method for the fine synchronization of theDrift Tube Local Trigger at LHC to be developed.
∗See Appendix A for the list of collaboration members
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1 IntroductionThe primary goal of the Compact Muon Solenoid (CMS) experiment [1] is to explore physicsat the TeV energy scale, exploiting the proton-proton collisions delivered by the Large HadronCollider (LHC) [2]. In order to achieve very high luminosity, the bunch crossing (BX) frequencyof the proton beams is large: 40.08 MHz. This large BX frequency requires an accurate synchro-nization of all the detector components that trigger the data acquisition.
In the muon barrel detector [3] the trigger electronics will start the signal processing with avariable delay since the time of flight (TOF) of a muon between the interaction point and thedetector varies from 12 ns for the closest muon station to 35 ns for the farthest one. The DriftTubes Local Trigger (DTLT) electronics generates trigger primitives based on the measurementsof the Drift Tubes (DT) detectors of the barrel muon system of CMS. In each chamber, the DTLTgenerates track segments from the alignment of hits and assigns the BX. A unique identifica-tion of the BX, independent of the muon momentum and direction, requires the phase of thesampling clock of the DTLT electronics to be adjusted with a precision of 1 ns. This adjustmentcan be achieved using a programmable delay (0–25 ns) available for each chamber. This ”finesynchronization” is the topic of this paper.
The method initially planned for the LHC operations consists of a scan of the fine delay foreach chamber to maximize the DTLT efficiency, using muons from LHC p-p collisions. Thismethod, although very reliable, has the disadvantage of being time consuming and requiringrather stable LHC running conditions. In this paper we present an alternative and independentway to synchronize the DT Local Trigger system. Cosmic ray muons are asynchronous withrespect to the clock and they span the whole 25 ns cycle, replicating the effect of many LHCruns with shifted phases of the sampling clock. The DTLT performance is optimal when themuon arrival time in a chamber has a well defined phase with respect to the local clock of thechamber. Cosmic ray muon data, taken in 2008 during the Cosmic Run At Four Tesla (CRAFT),have been used to measure this optimal phase for all chambers, based on the capability of theDT detector to measure precisely the track crossing time. These measurements, performedbefore the LHC start-up, can be used during data taking for a fast fine synchronization of theDTLTs. Muons are produced in p-p collisions at a well defined time with respect to the LHCclock; the local clock of each chamber will be adjusted such that the mean phase between themuon signal from the chamber and the local clock is equal to the optimal phase determinedwith the cosmic ray data analysis.
This paper is organized as follows. Section 2 describes the features of the DTLT, with particularattention to the fine synchronization issues specific to the DTLT electronics. Section 3 describesthe method which was used to synchronize the chambers during CRAFT. This method relieson the fact that cosmic ray muons arrive at random times with respect to the clock and cannot be applied to LHC collision data. Section 4 describes the measurement of the optimalphase of the DTLT trigger for all chambers performed with cosmic ray muon data taken in2008 during CRAFT. Section 5 explains how the results of Section 4 can be used to perform thesynchronization for normal LHC operation.
2 The DT local trigger and its synchronizationA detailed description of the CMS experiment can be found elsewhere [1]. The central featureof the CMS apparatus is a superconducting solenoid, of 6 m internal diameter, providing afield of 3.8 T. Within the field volume are the silicon pixel and strip tracker, the crystal elec-
2 2 The DT local trigger and its synchronization
tromagnetic calorimeter and the brass/scintillator hadron calorimeter. Muons are measured ingas-ionization detectors embedded in the steel return yoke. The Trigger and Timing Controlsystem (TTC)[4] distributes the 40.08 MHz clock and broadcasts the control signals and thegeneral Level 1 (L1) trigger strobe to the electronics of the experiment.
CMS uses a right-handed coordinate system, with the origin at the nominal collision point,the x-axis pointing to the center of the LHC, the y-axis pointing up (perpendicular to the LHCplane), and the z-axis along the anticlockwise-beam direction. The polar angle, θ, is measuredfrom the positive z-axis and the azimuthal angle, φ, is measured in the x-y plane.
The barrel muon detector [3] consists of 250 chambers arranged in four muon stations named,starting from the interaction point, MB1, MB2, MB3, and MB4, embedded in the steel yoke. Thesteel yoke is divided along the beam direction in five wheels, numbered from -2 to +2, each onewith 12 sectors in the transverse plane, sector 1 being at φ = 0. A chamber is made of layers ofdrift tubes staggered by half a cell. Layers are arranged in groups of four to form SuperLayers(SL). Two SLs measure the track in the r-φ plane, while in the three innermost stations a thirdSL measures also the track in the longitudinal plane (r-θ plane). Each DT chamber consists ofthe three (two in MB4 stations) SLs of drift tubes, their Read Out Boards (ROB) electronics, theTRigger Board (TRB) electronics and one Trigger and Timing Control receiver (TTCrx). TheTTCrx receives the 40.08 MHz clock from the TTC and broadcasts it both to the ROBs and tothe TRBs, hence a muon chamber can be considered as one intrinsically synchronous block.The signals of the DT wires are sampled and processed by the TRB to provide DTLT primi-
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Figure 1: DT Local Trigger quality classification. Hits along the muon track in the two SLs ofthe r-φ view are indicated by small circles; the output of the trigger primitives from a single SL,generated by the Bunch and Track Identifiers (BTI), and the trigger primitives correlating hitsin two SLs, generated by the TRack COrrelator device (TRACO), are shown for different cases.
tives, i.e. track segments and their associated BX, which are sent to the next steps of the muontrigger [5]. The front-end trigger device of the TRB is the Bunch and Track Identifier (BTI),which finds alignments of hits in each SL and assigns them a BX number [6]. The performancedepends on two relevant parameters: the drift velocity and the time pedestal for the drift timecomputation [7]. The device samples each wire at twice the LHC frequency. The time of signalsampling de-facto defines the uncertainty in the BTI “fit” of the hits and in the accuracy of thetrack segments parameters. The output of the BTI is provided at 40.08 MHz, selecting the bestalignments found in the last two sampling clocks.
All possible trigger primitive types delivered by the DTLT are sketched in Fig. 1. In each SL, thealignments of 3 out of 4, or 4 out of 4 hits are named Low (L) or High (H) quality, respectively. Ifsuch alignments are matched together between the two SLs, the quality of the trigger primitive
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Figure 2: DTLT fraction for HH and HH+HL trigger primitives with respect to all triggeredevents as a function of the TTCrx delay adjustment. This was measured using a bunched muontest beam and an external scintillator trigger [8].
then becomes HH, HL or LL. The best possible quality (HH) is delivered when hits of all theeight layers from the two SLs in the r-φ view are aligned. Accurate studies were performed witha ∼40 MHz bunched muon beam at the CERN SPS in 2003 and 2004 as reported in Ref. [8, 9].The DTLT efficiency was measured as a function of the TTCrx fine delays applied and hence ofthe time phase of the track with respect to the clock in the chamber. The observed fraction ofHH triggers is shown in Fig. 2; it ranges from ∼65% in a window of ∼10 ns to below 30% ina window of less than ∼5 ns; the curve has a periodicity of 25 ns. This structure is due to thefinite frequency at which the signal wires are sampled in the BTI.
In the LHC collisions, particles from the interaction region arrive in a muon station within analmost fixed time window, whose position depends on their average TOF. If the arrival timeof tracks, as seen by the DTLT electronics, were well defined with respect to the clock leadingedge (as was the case for the Test Beam data mentioned above), one would simply set the delaysuch that the arrival time is on the plateau shown in Fig. 2 and a ∼5 ns accuracy would besufficient. However, this arrival time, called muon arrival time hereafter, has a spread givenby the propagation of the signals from the track crossing point in the chamber to the front endelectronics which can be as long as 10 ns in the r-φ plane; additional contributions are relatedto variations in TOF due to the bending in the magnetic field and to different path lengths dueto the chamber dimensions (∼4 ns). The resulting time window of 10–15 ns should overlap asmuch as possible with the plateau. Since this plateau has a width of ∼10 ns, we need a ∼1 nsprecision to have an optimal efficiency of the HH triggers and the parent BX of all the tracksreaching a chamber uniquely identified.
The fine synchronization is illustrated for the four chambers of a sector in Fig. 3. The absolute
4 2 The DT local trigger and its synchronization
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Figure 3: Simplified visualization of a muon arrival time in the four stations of a sector of theDT barrel muon system as a function of the absolute time before and after ”fine synchroniza-tion”. The circle indicates the mean value of the arrival time of the tracks crossing a chamber.The BX clock leading edges of the different chambers are in a random position before fine syn-chronization (left plot). After fine synchronization (right plot) the phase of the clock edge inthe chambers has a specific value defined by maximizing the HH DTLT efficiency. For simplic-ity, this value is assumed here to be zero for each chamber, when the phase is measured withrespect to the leading edge of the clock.
time is shown on the horizontal axis. The black curve represents the track of an outwardspropagating muon coming from the interaction region. The circles indicate the mean value ofthe muon arrival time in each station. Before synchronization (left plot), the BX clock edgesof the different chambers are in a random position with respect to the absolute time due todifferences in the distributed clock signals. The fine synchronization consists in adjusting theclock in each chamber in order to have the maximum efficiency of HH triggers. As shown inFig. 2, such maximum efficiency is obtained when the muon arrival time in the chamber has awell defined phase with respect to the local clock. The resulting setting is shown in the rightpart of the figure. The spread of the arrival time of different tracks (due to different path lengthsand signal time propagation) is not reported. The time indicated by the circle represents themean value of the arrival time of the tracks from the interaction point to the chamber of muonswith a transverse momentum above a predefined value. The fine synchronization is achievedadjusting the time phase between the sampling clock and the machine clock, by setting the finedelay (104 ps step) provided inside the TTCrx of each chamber. The change of the samplingtime of the signals is equivalent to a modification of the reference time used in the track fitperformed by the trigger electronics.
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3 Cosmic ray muon synchronization for CRUZET and CRAFTThe CMS Collaboration conducted a month-long data-taking exercise, known as the CosmicRun At Four Tesla, during October-November 2008, with the goal of commissioning the exper-iment for extended operation [10]. With all the installed detector systems participating, CMSrecorded 270 million cosmic ray events with the solenoid at its nominal axial field strengthof 3.8 T. Prior to CRAFT and during the final installation phase of the experiment, a series ofone week long commissioning exercises, to record cosmic ray events, took place from May toSeptember 2008. Progressively, an increasing fraction of the experiment participated. Theseruns without magnetic field are known as the Cosmic RUn at ZEro Tesla (CRUZET). Threehundred million cosmic ray triggers were accumulated throughout such conditions.
The DT muon barrel detector provided the trigger throughout the cosmic ray data taking. Thefirst level trigger signal was given by the coincidence, at the same BX, of at least two DTLTs indifferent chambers in the same or neighboring sectors as described in Ref. [11]. Since cosmicrays have no time relation with the CMS clock and cross the detector with different anglesand rates, a first coarse synchronization has been made in order to have, in almost all events,the same latency of the L1 signal independently of the geographical position (chamber, sector,wheel) where the DTLTs were generated. This was performed by aligning the BX of the DTLTsof the different chambers, more details can be found in Ref. [11].
For the fine synchronization performed during CRUZET and CRAFT, specific data were col-lected triggering with only one chamber in each of the top sectors (sectors 3, 4, 5 of each wheel,see e.g. Ref. [12]). The BX number was assigned to the event by the DTLT of the chamber givingthe L1 trigger, whereas the BX distribution of HH triggers in chambers not contributing to theL1 was used to provide the direct measurement of the relative clock phase.
The periodic dependence of the BX distribution shape with respect to the TTCrx fine delay wasinspected using a dedicated set of 12 runs. In each run, the DTLT data of a whole sector wereread out using the L1 strobe generated by the MB3 station only. Run-by-run the clock phasesof the other three stations were moved in steps of 2 ns thus allowing a complete phase scan.The MB3 TTCrx delay was left fixed at 12.5 ns. The BX distribution of DTLT trigger primitiveswith HH quality is shown in Fig. 4 for one chamber of the MB4 station and for different valuesof its TTCrx delay. The BX distribution changes when shifting the phase, passing from a sharppeak, through intermediate stages, where events are shared in two contiguous BXs, to a sharppeak again, shifted by one BX with respect to the previous one. As an indicator of ”uniqueBX identification”, hence of a good fine synchronization, we used the difference, av, betweenthe average of the BX distribution and the BX with the maximum number of entries1. This isa convenient variable since it is independent of the latency actually used and is proper to eachchamber. Any muon trigger, after coarse synchronization, could have been used for collectingthe data: operationally we have chosen to trigger on a single chamber for simplicity, and MB3chambers were the obvious choice since they are the largest ones, giving the largest rate ofcosmic ray muons.
The distribution of av in ns is plotted in Fig. 5 for MB1, MB2 and MB4 as a function of theirlocal TTCrx delay. As expected, it ranges from −0.5 BX to 0.5 BX, i.e. from −12.5 ns to +12.5 ns,being zero by definition at the optimal phase value. These plots show that the average BX
1The BX of the MB3 chamber that provided the trigger signal could have been chosen as reference. The choice ofusing instead the BX peak value of each chamber as their own reference makes more apparent the specific scope ofthe local trigger fine synchronization with respect to the initial coarse synchronization. The initial coarse synchro-nization equalizes the cable paths chamber-to-chamber in order to give constant latency for the L1. While the coarsesynchronization aligns in time the BX peak values, the fine synchronization aims at optimizing the BX distribution.
6 3 Cosmic ray muon synchronization for CRUZET and CRAFT
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Figure 4: BX distribution of high quality (HH) trigger primitives in one chamber. Data are fromthe MB4 chamber of sector 11 of wheel −1, with a L1 signal taken from station MB3 only; thereare about 1500 events for each delay setting. The histograms are scaled to a common maximumheight. The observed average BX number with respect to the BX of the peak is indicated foreach delay. For example, when no delay is applied, the bin BX = 31 has the largest statistics andthe mean value of the BX distribution is 30.674, resulting in av = −0.326 BX. The shift of oneBX for the plots with delay above 6 ns is due to a change of the trigger latency.
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Figure 5: Average BX time for stations MB1, MB2 and MB4, measured with respect to the timeof the BX bin with the largest number of entries, as a function of the applied TTCrx delay. Dataare from sector 11 of wheel 1, with a L1 signal from station MB3 only, which is taken as referenceand had a constant TTCrx delay set at 12.5 ns. The average BX time for MB3 is consistent withzero as expected. There are about 1500 events for each delay setting.
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Figure 6: Distribution of the average BX time with respect to the time of the BX bin with thelargest number of entries before (left plot) and after (right plot) the delay adjustment for allchambers of sectors 3, 4, 5, 9, 10 and 11 of the wheels 0, 1 and 2. In these data, sector 9 of wheel+2 was not read out.
8 4 DT Local Trigger efficiency as a function of time and of clock phase with cosmic ray data
time depends linearly on the TTCrx fine delay, the deviations from linearity being less than2 ns. Having verified this linear dependence through this preliminary analysis, the fine syn-chronization for CRAFT was performed measuring the time of the average BX with the datacollected in each chamber and shifting their TTCrx fine delay accordingly. As an example, Fig. 6shows the distribution of av values for a subset of chambers before and after the TTCrx delayadjustment, triggering with all studied sectors. The distribution after the delay adjustment isnarrower.
Throughout the CRAFT run, the DT Track Finder provided a stable muon trigger rate of∼250 Hzas described in Ref. [11]. The stability of the synchronization was monitored and verified con-tinuously during the data taking. It has been checked using the mean value of the BX distribu-tion of primitives with HH quality in each chamber.
The method described here, used for the fine synchronization of cosmic ray data taking, canonly be applied when the arrival time of the tracks spans over a time range of at least one BXperiod. Therefore, the method cannot be applied successfully during LHC operation, wherethe arrival times of muons coming from the interaction region are confined within a range of10–15 ns.
4 DT Local Trigger efficiency as a function of time and of clockphase with cosmic ray data
As explained in Section 2, the DT local trigger performance is optimal when the muon arrivaltime in a chamber, as seen by the DTLT electronics, has a well defined phase with respect tothe local clock in the chamber itself. Cosmic rays, having a flat time distribution, allow thisoptimal phase to be determined, by measuring the HH trigger efficiency for each of the 250DT chambers as a function of the muon arrival time. The result, i.e. the optimal phase, is anintrinsic property of each chamber and is independent of the actual value of the TTCrx delay.
The arrival time of a track segment is reconstructed from the readout data of the DT chambersas explained in Ref. [13]. Close hits are grouped together by a pattern recognition algorithm.The track direction and position are determined assuming a straight line trajectory. In thefit, a common displacement of the hits from the wire position is treated as a free parameter.Assuming a constant drift velocity, this common displacement corresponds to a shift in thetime of the track. This reconstructed time shift has a resolution of about 3 ns [14].
For the purpose of this study, the reconstructed time shift (tsegment) is measured with respectto the leading edge of the clock of the chamber. The resulting distribution for all reconstructedsegments in the r-φ projection is shown in the left plot of Fig. 7 for one chamber. The subsetof the tracks in this chamber with an associated HH trigger is shown in the same plot. Thesecond local maximum, visible in the distribution of this subset, is associated with the fractionof events triggered in the chamber at a BX contiguous to the one defined by the L1 trigger.Given the periodical behavior of the efficiency, these distributions were folded in the central25 ns interval, as shown in the right plot, in order to increase statistics. Hereafter, the tsegmentfolded in 25 ns interval is referred to as the ”Phase”.
In Fig. 8, for each of the four chambers of one sector, the Phase of all tracks and of the ones withan associated HH trigger are shown on the left side; the HH trigger efficiency, i.e the ratio ofthe number of tracks with HH quality to the total number of tracks in the chamber, is shown onthe right side. The plots show that the DTLT efficiency as a function of Phase is maximal over aplateau ∼10 ns wide and has a minimum in a region ∼5 ns wide (similar to the one measured
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Figure 7: Left: time distribution of track segments in one chamber with (dash-dotted his-togram) and without (continuous histogram) the HH quality requirement. The minimum inthe distribution of HH triggers locates the boundary between two BXs. Right: the same distri-butions folded into a 25 ns interval.
10 4 DT Local Trigger efficiency as a function of time and of clock phase with cosmic ray data
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12 4 DT Local Trigger efficiency as a function of time and of clock phase with cosmic ray data
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Figure 11: DTLT of HH quality efficiency as a function of Phase for five ranges of the trackincidence angle: [−25,−15], [−15,−5], [−5,+5], [+5,+15], [+15,+25] degrees. The Phase ofthe minimum efficiency has no dependence on the angle, as shown in the bottom right plot.
for all DT chambers with the local trigger data from one CRAFT run. Results from other runsagree, within statistical and systematic errors. The errors on Phasemin of the chambers in thevertical sectors (namely sectors 1 and 7) are much larger than the others because of the poorerreconstruction efficiency and accuracy caused by the large angle of cosmic ray tracks in thesesectors. Systematic errors, caused by the calibration parameters [15] used for referring the timeto the clock leading edge, are not reported. In the chambers of sectors oriented close to the hor-izontal direction (sectors 3, 4, 5, and 9, 10, 11) these errors are lower than 1 ns; in the chambersof other sectors they can be as large as a few ns. The results are summarized in Fig. 10, wherethe distributions of Phasemin, shown individually in Fig. 9, are plotted for the four station typesseparately. The Phasemin is the same within a few ns for each chamber type (a Gaussian fit tothe distribution of Phasemin returns a σ smaller than 1 ns). This is a consequence of similaritiesin the construction of the chambers and their operating conditions, and can be used to reducethe systematic bias which affects the measurements in the vertical sectors. It should be notedthat in the MB1 chambers of wheels +2 and−2, Phasemin is different from that in the other MB1chambers. This is an effect of the drift velocity in these chambers, which is different from theothers due to the stray magnetic field, as already observed in previous measurements [16, 17].No dependence of Phasemin on the track incidence angle was observed in the range of −25 to+25 degrees, corresponding to the angular interval expected for high transverse momentummuons produced at LHC. Figure 11 shows the efficiency curves as a function of Phase, mea-
14 5 Fine synchronization at the LHC start-up
sured for five ranges of angles. The plot on the bottom right side shows Phasemin as a functionof the angle.
5 Fine synchronization at the LHC start-upThe study reported in Ref. [12] shows that, summing over all trigger qualities (HH, HL, LL), theefficiency of DTLT primitives is above ∼60% for any value of the local clock phase, with an av-erage value of ∼80% . Therefore, at the LHC start-up, after the initial coarse synchronization2,the DT chambers are expected to trigger on muons from p-p interactions with a reasonable effi-ciency even before any fine synchronization. Triggers from other detectors will be used as well.Since the latency accuracy of such triggers will be in a range of two BXs, the segment recon-struction and the related time measurement in the DT chambers will be carried out correctly.At the LHC start-up, it will therefore be possible to produce the Phase distribution of tracks in
[ns]segmentt-10 -5 0 5 10
HH
trig
. e
ffic
ien
cy
0
0.2
0.4
0.6
0.8
1
0
5
10
15
20
25
30
35HH trig. eff. from cosmic data
Simulated muons
Eve
nts
/2
.5n
sCMS 2008
Figure 12: Distribution of tsegment for simulated muons from pp→ µX reaching a DT chamber(histogram, units on the right side axis), together with the corresponding efficiency curve, asmeasured with cosmic rays (crosses).
any chamber. This distribution is expected to be much narrower than the one obtained withcosmic rays, and to peak at a fixed position. In order to get the maximum HH trigger efficiency,the peak has to be moved to the position of maximum efficiency already obtained with cosmicrays as described in Section 4. The fine synchronization will consist in the application, chamberby chamber, of the optimal delay, obtained as the difference between the phase peak at start-upand the phase of the maximum of the efficiency.
Muons from p-p interactions have an arrival time in a chamber with a spread of 10–15 ns,Because the tracks are not distributed randomly with respect to the clock, the mean value canbe determined with an accuracy of ∼1 ns with only a few hundred tracks per sector coming
2 To achieve this coarse synchronization, the TTCrx delays of the different chambers can be shifted from thevalues used during CRAFT, by an amount which can be determined from the TOF difference between cosmicmuons and muons coming from p-p interactions.
15
from the interaction point. The time needed to collect a few hundred muons per chambershould be very short since the acquisition will take place in all chambers concurrently, withoutany need to upload specific parameters to the DTLT electronics, as would be the case for a scanof the TTCrx delays. Moreover, the procedure can be applied to data collected either centrallyor with the DT local data acquisition, with any source of the L1 trigger. The rate of backgroundcosmic ray events is expected to be negligible, reduced by a factor greater than 103 with respectto the ∼250 Hz measured in the CRAFT runs, by requiring pointing tracks with transversemomentum larger than ∼10 GeV/c, at trigger and at reconstruction level.
In Fig. 12, the distribution of tsegment for muons coming from a sample of simulated pp→ µXevents, from LHC collision, is shown for one chamber. Even though at the LHC start-up wemay expect distributions with different mean values, their widths should be similar to the onereported. The tsegment distribution for these muons will be narrow compared to the width of themaximum efficiency plateau; this confirms that the precision of the measurements presentedhere is enough to ensure a good synchronization of the DT trigger for muons produced in p-pcollisions.
6 SummaryThe random arrival time of cosmic ray muons allowed several synchronization aspects of theDrift Tube Local Trigger to be studied. The method used for the synchronization for cosmic raydata has been presented. The stability of the synchronization over a period of several monthshas been verified.
A new method to achieve the DTLT synchronization at the LHC was presented. Cosmic rayevents, which span the whole 25 ns clock cycle, were used to measure the efficiency curve ofhigh quality DT local trigger primitives in each chamber, as a function of the phase of the re-constructed muon arrival time with respect to the local clock edge. The optimal phase betweenthe muon signal and the local clock, ensuring maximal efficiency and unique BX identification,was determined for each chamber. For most chambers, a precision better than 1 ns was reached.For chambers belonging to the same wheel and station, the optimal phases are similar, becausethe chambers are of identical design and are operated under the same conditions. This can beused to reduce the systematic bias which affects the measurements for the chambers where thedirection of cosmic ray muons is very different from that of muons from p-p collisions.
Since these optimal phases have now been determined, a few hundred tracks per chamber willbe sufficient to perform the synchronization of the DT trigger very quickly at the LHC start-up.Compared to the method envisaged originally, all the required data can be collected with asingle running configuration.
AcknowledgmentsWe thank the technical and administrative staff at CERN and other CMS Institutes, and ac-knowledge support from: FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ,and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIEN-CIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia);Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG,and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India);IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONA-CYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR
16 6 Summary
(Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia);MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAKand TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA). Individuals have receivedsupport from the Marie-Curie IEF program (European Union); the Leventis Foundation; the A.P. Sloan Foundation; and the Alexander von Humboldt Foundation.
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17
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19
A The CMS CollaborationYerevan Physics Institute, Yerevan, ArmeniaS. Chatrchyan, V. Khachatryan, A.M. Sirunyan
Institut fur Hochenergiephysik der OeAW, Wien, AustriaW. Adam, B. Arnold, H. Bergauer, T. Bergauer, M. Dragicevic, M. Eichberger, J. Ero, M. Friedl,R. Fruhwirth, V.M. Ghete, J. Hammer1, S. Hansel, M. Hoch, N. Hormann, J. Hrubec, M. Jeitler,G. Kasieczka, K. Kastner, M. Krammer, D. Liko, I. Magrans de Abril, I. Mikulec, F. Mittermayr,B. Neuherz, M. Oberegger, M. Padrta, M. Pernicka, H. Rohringer, S. Schmid, R. Schofbeck,T. Schreiner, R. Stark, H. Steininger, J. Strauss, A. Taurok, F. Teischinger, T. Themel, D. Uhl,P. Wagner, W. Waltenberger, G. Walzel, E. Widl, C.-E. Wulz
National Centre for Particle and High Energy Physics, Minsk, BelarusV. Chekhovsky, O. Dvornikov, I. Emeliantchik, A. Litomin, V. Makarenko, I. Marfin,V. Mossolov, N. Shumeiko, A. Solin, R. Stefanovitch, J. Suarez Gonzalez, A. Tikhonov
Research Institute for Nuclear Problems, Minsk, BelarusA. Fedorov, A. Karneyeu, M. Korzhik, V. Panov, R. Zuyeuski
Research Institute of Applied Physical Problems, Minsk, BelarusP. Kuchinsky
Universiteit Antwerpen, Antwerpen, BelgiumW. Beaumont, L. Benucci, M. Cardaci, E.A. De Wolf, E. Delmeire, D. Druzhkin, M. Hashemi,X. Janssen, T. Maes, L. Mucibello, S. Ochesanu, R. Rougny, M. Selvaggi, H. Van Haevermaet,P. Van Mechelen, N. Van Remortel
Vrije Universiteit Brussel, Brussel, BelgiumV. Adler, S. Beauceron, S. Blyweert, J. D’Hondt, S. De Weirdt, O. Devroede, J. Heyninck, A. Ka-logeropoulos, J. Maes, M. Maes, M.U. Mozer, S. Tavernier, W. Van Doninck1, P. Van Mulders,I. Villella
Universite Libre de Bruxelles, Bruxelles, BelgiumO. Bouhali, E.C. Chabert, O. Charaf, B. Clerbaux, G. De Lentdecker, V. Dero, S. Elgammal,A.P.R. Gay, G.H. Hammad, P.E. Marage, S. Rugovac, C. Vander Velde, P. Vanlaer, J. Wickens
Ghent University, Ghent, BelgiumM. Grunewald, B. Klein, A. Marinov, D. Ryckbosch, F. Thyssen, M. Tytgat, L. Vanelderen,P. Verwilligen
Universite Catholique de Louvain, Louvain-la-Neuve, BelgiumS. Basegmez, G. Bruno, J. Caudron, C. Delaere, P. Demin, D. Favart, A. Giammanco,G. Gregoire, V. Lemaitre, O. Militaru, S. Ovyn, K. Piotrzkowski1, L. Quertenmont, N. Schul
Universite de Mons, Mons, BelgiumN. Beliy, E. Daubie
Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, BrazilG.A. Alves, M.E. Pol, M.H.G. Souza
Universidade do Estado do Rio de Janeiro, Rio de Janeiro, BrazilW. Carvalho, D. De Jesus Damiao, C. De Oliveira Martins, S. Fonseca De Souza, L. Mundim,V. Oguri, A. Santoro, S.M. Silva Do Amaral, A. Sznajder
Instituto de Fisica Teorica, Universidade Estadual Paulista, Sao Paulo, Brazil
20 A The CMS Collaboration
T.R. Fernandez Perez Tomei, M.A. Ferreira Dias, E. M. Gregores2, S.F. Novaes
Institute for Nuclear Research and Nuclear Energy, Sofia, BulgariaK. Abadjiev1, T. Anguelov, J. Damgov, N. Darmenov1, L. Dimitrov, V. Genchev1, P. Iaydjiev,S. Piperov, S. Stoykova, G. Sultanov, R. Trayanov, I. Vankov
University of Sofia, Sofia, BulgariaA. Dimitrov, M. Dyulendarova, V. Kozhuharov, L. Litov, E. Marinova, M. Mateev, B. Pavlov,P. Petkov, Z. Toteva1
Institute of High Energy Physics, Beijing, ChinaG.M. Chen, H.S. Chen, W. Guan, C.H. Jiang, D. Liang, B. Liu, X. Meng, J. Tao, J. Wang, Z. Wang,Z. Xue, Z. Zhang
State Key Lab. of Nucl. Phys. and Tech., Peking University, Beijing, ChinaY. Ban, J. Cai, Y. Ge, S. Guo, Z. Hu, Y. Mao, S.J. Qian, H. Teng, B. Zhu
Universidad de Los Andes, Bogota, ColombiaC. Avila, M. Baquero Ruiz, C.A. Carrillo Montoya, A. Gomez, B. Gomez Moreno, A.A. OcampoRios, A.F. Osorio Oliveros, D. Reyes Romero, J.C. Sanabria
Technical University of Split, Split, CroatiaN. Godinovic, K. Lelas, R. Plestina, D. Polic, I. Puljak
University of Split, Split, CroatiaZ. Antunovic, M. Dzelalija
Institute Rudjer Boskovic, Zagreb, CroatiaV. Brigljevic, S. Duric, K. Kadija, S. Morovic
University of Cyprus, Nicosia, CyprusR. Fereos, M. Galanti, J. Mousa, A. Papadakis, F. Ptochos, P.A. Razis, D. Tsiakkouri, Z. Zinonos
National Institute of Chemical Physics and Biophysics, Tallinn, EstoniaA. Hektor, M. Kadastik, K. Kannike, M. Muntel, M. Raidal, L. Rebane
Helsinki Institute of Physics, Helsinki, FinlandE. Anttila, S. Czellar, J. Harkonen, A. Heikkinen, V. Karimaki, R. Kinnunen, J. Klem, M.J. Ko-rtelainen, T. Lampen, K. Lassila-Perini, S. Lehti, T. Linden, P. Luukka, T. Maenpaa, J. Nysten,E. Tuominen, J. Tuominiemi, D. Ungaro, L. Wendland
Lappeenranta University of Technology, Lappeenranta, FinlandK. Banzuzi, A. Korpela, T. Tuuva
Laboratoire d’Annecy-le-Vieux de Physique des Particules, IN2P3-CNRS, Annecy-le-Vieux,FranceP. Nedelec, D. Sillou
DSM/IRFU, CEA/Saclay, Gif-sur-Yvette, FranceM. Besancon, R. Chipaux, M. Dejardin, D. Denegri, J. Descamps, B. Fabbro, J.L. Faure, F. Ferri,S. Ganjour, F.X. Gentit, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry, M.C. Lemaire,E. Locci, J. Malcles, M. Marionneau, L. Millischer, J. Rander, A. Rosowsky, D. Rousseau,M. Titov, P. Verrecchia
Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, FranceS. Baffioni, L. Bianchini, M. Bluj3, P. Busson, C. Charlot, L. Dobrzynski, R. Granier de Cas-sagnac, M. Haguenauer, P. Mine, P. Paganini, Y. Sirois, C. Thiebaux, A. Zabi
21
Institut Pluridisciplinaire Hubert Curien, Universite de Strasbourg, Universite de HauteAlsace Mulhouse, CNRS/IN2P3, Strasbourg, FranceJ.-L. Agram4, A. Besson, D. Bloch, D. Bodin, J.-M. Brom, E. Conte4, F. Drouhin4, J.-C. Fontaine4,D. Gele, U. Goerlach, L. Gross, P. Juillot, A.-C. Le Bihan, Y. Patois, J. Speck, P. Van Hove
Universite de Lyon, Universite Claude Bernard Lyon 1, CNRS-IN2P3, Institut de PhysiqueNucleaire de Lyon, Villeurbanne, FranceC. Baty, M. Bedjidian, J. Blaha, G. Boudoul, H. Brun, N. Chanon, R. Chierici, D. Contardo,P. Depasse, T. Dupasquier, H. El Mamouni, F. Fassi5, J. Fay, S. Gascon, B. Ille, T. Kurca, T. LeGrand, M. Lethuillier, N. Lumb, L. Mirabito, S. Perries, M. Vander Donckt, P. Verdier
E. Andronikashvili Institute of Physics, Academy of Science, Tbilisi, GeorgiaN. Djaoshvili, N. Roinishvili, V. Roinishvili
Institute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi,GeorgiaN. Amaglobeli
RWTH Aachen University, I. Physikalisches Institut, Aachen, GermanyR. Adolphi, G. Anagnostou, R. Brauer, W. Braunschweig, M. Edelhoff, H. Esser, L. Feld,W. Karpinski, A. Khomich, K. Klein, N. Mohr, A. Ostaptchouk, D. Pandoulas, G. Pierschel,F. Raupach, S. Schael, A. Schultz von Dratzig, G. Schwering, D. Sprenger, M. Thomas, M. Weber,B. Wittmer, M. Wlochal
RWTH Aachen University, III. Physikalisches Institut A, Aachen, GermanyO. Actis, G. Altenhofer, W. Bender, P. Biallass, M. Erdmann, G. Fetchenhauer1, J. Frangenheim,T. Hebbeker, G. Hilgers, A. Hinzmann, K. Hoepfner, C. Hof, M. Kirsch, T. Klimkovich,P. Kreuzer1, D. Lanske†, M. Merschmeyer, A. Meyer, B. Philipps, H. Pieta, H. Reithler,S.A. Schmitz, L. Sonnenschein, M. Sowa, J. Steggemann, H. Szczesny, D. Teyssier, C. Zeidler
RWTH Aachen University, III. Physikalisches Institut B, Aachen, GermanyM. Bontenackels, M. Davids, M. Duda, G. Flugge, H. Geenen, M. Giffels, W. Haj Ahmad, T. Her-manns, D. Heydhausen, S. Kalinin, T. Kress, A. Linn, A. Nowack, L. Perchalla, M. Poettgens,O. Pooth, P. Sauerland, A. Stahl, D. Tornier, M.H. Zoeller
Deutsches Elektronen-Synchrotron, Hamburg, GermanyM. Aldaya Martin, U. Behrens, K. Borras, A. Campbell, E. Castro, D. Dammann, G. Eckerlin,A. Flossdorf, G. Flucke, A. Geiser, D. Hatton, J. Hauk, H. Jung, M. Kasemann, I. Katkov,C. Kleinwort, H. Kluge, A. Knutsson, E. Kuznetsova, W. Lange, W. Lohmann, R. Mankel1,M. Marienfeld, A.B. Meyer, S. Miglioranzi, J. Mnich, M. Ohlerich, J. Olzem, A. Parenti,C. Rosemann, R. Schmidt, T. Schoerner-Sadenius, D. Volyanskyy, C. Wissing, W.D. Zeuner1
University of Hamburg, Hamburg, GermanyC. Autermann, F. Bechtel, J. Draeger, D. Eckstein, U. Gebbert, K. Kaschube, G. Kaussen,R. Klanner, B. Mura, S. Naumann-Emme, F. Nowak, U. Pein, C. Sander, P. Schleper, T. Schum,H. Stadie, G. Steinbruck, J. Thomsen, R. Wolf
Institut fur Experimentelle Kernphysik, Karlsruhe, GermanyJ. Bauer, P. Blum, V. Buege, A. Cakir, T. Chwalek, W. De Boer, A. Dierlamm, G. Dirkes,M. Feindt, U. Felzmann, M. Frey, A. Furgeri, J. Gruschke, C. Hackstein, F. Hartmann1,S. Heier, M. Heinrich, H. Held, D. Hirschbuehl, K.H. Hoffmann, S. Honc, C. Jung, T. Kuhr,T. Liamsuwan, D. Martschei, S. Mueller, Th. Muller, M.B. Neuland, M. Niegel, O. Oberst,A. Oehler, J. Ott, T. Peiffer, D. Piparo, G. Quast, K. Rabbertz, F. Ratnikov, N. Ratnikova, M. Renz,C. Saout1, G. Sartisohn, A. Scheurer, P. Schieferdecker, F.-P. Schilling, G. Schott, H.J. Simonis,
22 A The CMS Collaboration
F.M. Stober, P. Sturm, D. Troendle, A. Trunov, W. Wagner, J. Wagner-Kuhr, M. Zeise, V. Zhukov6,E.B. Ziebarth
Institute of Nuclear Physics ”Demokritos”, Aghia Paraskevi, GreeceG. Daskalakis, T. Geralis, K. Karafasoulis, A. Kyriakis, D. Loukas, A. Markou, C. Markou,C. Mavrommatis, E. Petrakou, A. Zachariadou
University of Athens, Athens, GreeceL. Gouskos, P. Katsas, A. Panagiotou1
University of Ioannina, Ioannina, GreeceI. Evangelou, P. Kokkas, N. Manthos, I. Papadopoulos, V. Patras, F.A. Triantis
KFKI Research Institute for Particle and Nuclear Physics, Budapest, HungaryG. Bencze1, L. Boldizsar, G. Debreczeni, C. Hajdu1, S. Hernath, P. Hidas, D. Horvath7, K. Kra-jczar, A. Laszlo, G. Patay, F. Sikler, N. Toth, G. Vesztergombi
Institute of Nuclear Research ATOMKI, Debrecen, HungaryN. Beni, G. Christian, J. Imrek, J. Molnar, D. Novak, J. Palinkas, G. Szekely, Z. Szillasi1,K. Tokesi, V. Veszpremi
University of Debrecen, Debrecen, HungaryA. Kapusi, G. Marian, P. Raics, Z. Szabo, Z.L. Trocsanyi, B. Ujvari, G. Zilizi
Panjab University, Chandigarh, IndiaS. Bansal, H.S. Bawa, S.B. Beri, V. Bhatnagar, M. Jindal, M. Kaur, R. Kaur, J.M. Kohli,M.Z. Mehta, N. Nishu, L.K. Saini, A. Sharma, A. Singh, J.B. Singh, S.P. Singh
University of Delhi, Delhi, IndiaS. Ahuja, S. Arora, S. Bhattacharya8, S. Chauhan, B.C. Choudhary, P. Gupta, S. Jain, S. Jain,M. Jha, A. Kumar, K. Ranjan, R.K. Shivpuri, A.K. Srivastava
Bhabha Atomic Research Centre, Mumbai, IndiaR.K. Choudhury, D. Dutta, S. Kailas, S.K. Kataria, A.K. Mohanty, L.M. Pant, P. Shukla, A. Top-kar
Tata Institute of Fundamental Research - EHEP, Mumbai, IndiaT. Aziz, M. Guchait9, A. Gurtu, M. Maity10, D. Majumder, G. Majumder, K. Mazumdar,A. Nayak, A. Saha, K. Sudhakar
Tata Institute of Fundamental Research - HECR, Mumbai, IndiaS. Banerjee, S. Dugad, N.K. Mondal
Institute for Studies in Theoretical Physics & Mathematics (IPM), Tehran, IranH. Arfaei, H. Bakhshiansohi, A. Fahim, A. Jafari, M. Mohammadi Najafabadi, A. Moshaii,S. Paktinat Mehdiabadi, S. Rouhani, B. Safarzadeh, M. Zeinali
University College Dublin, Dublin, IrelandM. Felcini
INFN Sezione di Bari a, Universita di Bari b, Politecnico di Bari c, Bari, ItalyM. Abbresciaa ,b, L. Barbonea, F. Chiumaruloa, A. Clementea, A. Colaleoa, D. Creanzaa,c,G. Cuscelaa, N. De Filippisa, M. De Palmaa,b, G. De Robertisa, G. Donvitoa, F. Fedelea, L. Fiorea,M. Francoa, G. Iasellia,c, N. Lacalamitaa, F. Loddoa, L. Lusitoa,b, G. Maggia,c, M. Maggia,N. Mannaa,b, B. Marangellia ,b, S. Mya ,c, S. Natalia ,b, S. Nuzzoa,b, G. Papagnia, S. Piccolomoa,G.A. Pierroa, C. Pintoa, A. Pompilia ,b, G. Pugliesea ,c, R. Rajana, A. Ranieria, F. Romanoa,c,
23
G. Rosellia,b, G. Selvaggia ,b, Y. Shindea, L. Silvestrisa, S. Tupputia ,b, G. Zitoa
INFN Sezione di Bologna a, Universita di Bologna b, Bologna, ItalyG. Abbiendia, W. Bacchia ,b, A.C. Benvenutia, M. Boldinia, D. Bonacorsia, S. Braibant-Giacomellia,b, V.D. Cafaroa, S.S. Caiazzaa, P. Capiluppia,b, A. Castroa ,b, F.R. Cavalloa,G. Codispotia,b, M. Cuffiania,b, I. D’Antonea, G.M. Dallavallea,1, F. Fabbria, A. Fanfania ,b,D. Fasanellaa, P. Giacomellia, V. Giordanoa, M. Giuntaa ,1, C. Grandia, M. Guerzonia,S. Marcellinia, G. Masettia,b, A. Montanaria, F.L. Navarriaa,b, F. Odoricia, G. Pellegrinia,A. Perrottaa, A.M. Rossia,b, T. Rovellia ,b, G. Sirolia ,b, G. Torromeoa, R. Travaglinia ,b
INFN Sezione di Catania a, Universita di Catania b, Catania, ItalyS. Albergoa,b, S. Costaa,b, R. Potenzaa,b, A. Tricomia,b, C. Tuvea
INFN Sezione di Firenze a, Universita di Firenze b, Firenze, ItalyG. Barbaglia, G. Broccoloa,b, V. Ciullia ,b, C. Civininia, R. D’Alessandroa ,b, E. Focardia ,b,S. Frosalia,b, E. Galloa, C. Gentaa,b, G. Landia ,b, P. Lenzia,b ,1, M. Meschinia, S. Paolettia,G. Sguazzonia, A. Tropianoa
INFN Laboratori Nazionali di Frascati, Frascati, ItalyL. Benussi, M. Bertani, S. Bianco, S. Colafranceschi11, D. Colonna11, F. Fabbri, M. Giardoni,L. Passamonti, D. Piccolo, D. Pierluigi, B. Ponzio, A. Russo
INFN Sezione di Genova, Genova, ItalyP. Fabbricatore, R. Musenich
INFN Sezione di Milano-Biccoca a, Universita di Milano-Bicocca b, Milano, ItalyA. Benagliaa, M. Callonia, G.B. Ceratia ,b ,1, P. D’Angeloa, F. De Guioa, F.M. Farinaa, A. Ghezzia,P. Govonia,b, M. Malbertia,b ,1, S. Malvezzia, A. Martellia, D. Menascea, V. Miccioa,b, L. Moronia,P. Negria,b, M. Paganonia ,b, D. Pedrinia, A. Pulliaa ,b, S. Ragazzia ,b, N. Redaellia, S. Salaa,R. Salernoa,b, T. Tabarelli de Fatisa ,b, V. Tancinia,b, S. Taronia ,b
INFN Sezione di Napoli a, Universita di Napoli ”Federico II” b, Napoli, ItalyS. Buontempoa, N. Cavalloa, A. Cimminoa ,b ,1, M. De Gruttolaa,b ,1, F. Fabozzia,12, A.O.M. Iorioa,L. Listaa, D. Lomidzea, P. Nolia ,b, P. Paoluccia, C. Sciaccaa,b
INFN Sezione di Padova a, Universita di Padova b, Padova, ItalyP. Azzia,1, N. Bacchettaa, L. Barcellana, P. Bellana ,b ,1, M. Bellatoa, M. Benettonia, M. Biasottoa ,13,D. Biselloa,b, E. Borsatoa ,b, A. Brancaa, R. Carlina ,b, L. Castellania, P. Checchiaa, E. Contia,F. Dal Corsoa, M. De Mattiaa,b, T. Dorigoa, U. Dossellia, F. Fanzagoa, F. Gasparinia ,b,U. Gasparinia,b, P. Giubilatoa,b, F. Gonellaa, A. Greselea,14, M. Gulminia ,13, A. Kaminskiya ,b,S. Lacapraraa ,13, I. Lazzizzeraa ,14, M. Margonia ,b, G. Marona ,13, S. Mattiazzoa,b, M. Mazzucatoa,M. Meneghellia, A.T. Meneguzzoa,b, M. Michelottoa, F. Montecassianoa, M. Nespoloa,M. Passaseoa, M. Pegoraroa, L. Perrozzia, N. Pozzobona ,b, P. Ronchesea,b, F. Simonettoa,b,N. Tonioloa, E. Torassaa, M. Tosia ,b, A. Triossia, S. Vaninia ,b, S. Venturaa, P. Zottoa,b,G. Zumerlea,b
INFN Sezione di Pavia a, Universita di Pavia b, Pavia, ItalyP. Baessoa,b, U. Berzanoa, S. Bricolaa, M.M. Necchia ,b, D. Paganoa,b, S.P. Rattia,b, C. Riccardia,b,P. Torrea ,b, A. Vicinia, P. Vituloa,b, C. Viviania,b
INFN Sezione di Perugia a, Universita di Perugia b, Perugia, ItalyD. Aisaa, S. Aisaa, E. Babuccia, M. Biasinia,b, G.M. Bileia, B. Caponeria,b, B. Checcuccia, N. Dinua,L. Fanoa, L. Farnesinia, P. Laricciaa,b, A. Lucaronia,b, G. Mantovania ,b, A. Nappia,b, A. Pilusoa,V. Postolachea, A. Santocchiaa,b, L. Servolia, D. Tonoiua, A. Vedaeea, R. Volpea ,b
24 A The CMS Collaboration
INFN Sezione di Pisa a, Universita di Pisa b, Scuola Normale Superiore di Pisa c, Pisa, ItalyP. Azzurria ,c, G. Bagliesia, J. Bernardinia,b, L. Berrettaa, T. Boccalia, A. Boccia ,c, L. Borrelloa,c,F. Bosia, F. Calzolaria, R. Castaldia, R. Dell’Orsoa, F. Fioria,b, L. Foaa ,c, S. Gennaia,c, A. Giassia,A. Kraana, F. Ligabuea ,c, T. Lomtadzea, F. Mariania, L. Martinia, M. Massaa, A. Messineoa ,b,A. Moggia, F. Pallaa, F. Palmonaria, G. Petragnania, G. Petrucciania ,c, F. Raffaellia, S. Sarkara,G. Segneria, A.T. Serbana, P. Spagnoloa ,1, R. Tenchinia ,1, S. Tolainia, G. Tonellia,b ,1, A. Venturia,P.G. Verdinia
INFN Sezione di Roma a, Universita di Roma ”La Sapienza” b, Roma, ItalyS. Baccaroa ,15, L. Baronea,b, A. Bartolonia, F. Cavallaria ,1, I. Dafineia, D. Del Rea ,b, E. DiMarcoa ,b, M. Diemoza, D. Francia,b, E. Longoa,b, G. Organtinia ,b, A. Palmaa ,b, F. Pandolfia ,b,R. Paramattia,1, F. Pellegrinoa, S. Rahatloua ,b, C. Rovellia
INFN Sezione di Torino a, Universita di Torino b, Universita del Piemonte Orientale (No-vara) c, Torino, ItalyG. Alampia, N. Amapanea ,b, R. Arcidiaconoa,b, S. Argiroa,b, M. Arneodoa ,c, C. Biinoa,M.A. Borgiaa,b, C. Bottaa,b, N. Cartigliaa, R. Castelloa ,b, G. Cerminaraa,b, M. Costaa ,b,D. Dattolaa, G. Dellacasaa, N. Demariaa, G. Dugheraa, F. Dumitrachea, A. Grazianoa ,b,C. Mariottia, M. Maronea,b, S. Masellia, E. Migliorea,b, G. Milaa ,b, V. Monacoa ,b, M. Musicha ,b,M. Nervoa ,b, M.M. Obertinoa ,c, S. Oggeroa,b, R. Paneroa, N. Pastronea, M. Pelliccionia ,b,A. Romeroa,b, M. Ruspaa,c, R. Sacchia,b, A. Solanoa,b, A. Staianoa, P.P. Trapania ,b ,1, D. Trocinoa ,b,A. Vilela Pereiraa,b, L. Viscaa,b, A. Zampieria
INFN Sezione di Trieste a, Universita di Trieste b, Trieste, ItalyF. Ambroglinia ,b, S. Belfortea, F. Cossuttia, G. Della Riccaa,b, B. Gobboa, A. Penzoa
Kyungpook National University, Daegu, KoreaS. Chang, J. Chung, D.H. Kim, G.N. Kim, D.J. Kong, H. Park, D.C. Son
Wonkwang University, Iksan, KoreaS.Y. Bahk
Chonnam National University, Kwangju, KoreaS. Song
Konkuk University, Seoul, KoreaS.Y. Jung
Korea University, Seoul, KoreaB. Hong, H. Kim, J.H. Kim, K.S. Lee, D.H. Moon, S.K. Park, H.B. Rhee, K.S. Sim
Seoul National University, Seoul, KoreaJ. Kim
University of Seoul, Seoul, KoreaM. Choi, G. Hahn, I.C. Park
Sungkyunkwan University, Suwon, KoreaS. Choi, Y. Choi, J. Goh, H. Jeong, T.J. Kim, J. Lee, S. Lee
Vilnius University, Vilnius, LithuaniaM. Janulis, D. Martisiute, P. Petrov, T. Sabonis
Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, MexicoH. Castilla Valdez1, A. Sanchez Hernandez
25
Universidad Iberoamericana, Mexico City, MexicoS. Carrillo Moreno
Universidad Autonoma de San Luis Potosı, San Luis Potosı, MexicoA. Morelos Pineda
University of Auckland, Auckland, New ZealandP. Allfrey, R.N.C. Gray, D. Krofcheck
University of Canterbury, Christchurch, New ZealandN. Bernardino Rodrigues, P.H. Butler, T. Signal, J.C. Williams
National Centre for Physics, Quaid-I-Azam University, Islamabad, PakistanM. Ahmad, I. Ahmed, W. Ahmed, M.I. Asghar, M.I.M. Awan, H.R. Hoorani, I. Hussain,W.A. Khan, T. Khurshid, S. Muhammad, S. Qazi, H. Shahzad
Institute of Experimental Physics, Warsaw, PolandM. Cwiok, R. Dabrowski, W. Dominik, K. Doroba, M. Konecki, J. Krolikowski, K. Pozniak16,R. Romaniuk, W. Zabolotny16, P. Zych
Soltan Institute for Nuclear Studies, Warsaw, PolandT. Frueboes, R. Gokieli, L. Goscilo, M. Gorski, M. Kazana, K. Nawrocki, M. Szleper, G. Wrochna,P. Zalewski
Laboratorio de Instrumentacao e Fısica Experimental de Partıculas, Lisboa, PortugalN. Almeida, L. Antunes Pedro, P. Bargassa, A. David, P. Faccioli, P.G. Ferreira Parracho,M. Freitas Ferreira, M. Gallinaro, M. Guerra Jordao, P. Martins, G. Mini, P. Musella, J. Pela,L. Raposo, P.Q. Ribeiro, S. Sampaio, J. Seixas, J. Silva, P. Silva, D. Soares, M. Sousa, J. Varela,H.K. Wohri
Joint Institute for Nuclear Research, Dubna, RussiaI. Altsybeev, I. Belotelov, P. Bunin, Y. Ershov, I. Filozova, M. Finger, M. Finger Jr., A. Golunov,I. Golutvin, N. Gorbounov, V. Kalagin, A. Kamenev, V. Karjavin, V. Konoplyanikov, V. Ko-renkov, G. Kozlov, A. Kurenkov, A. Lanev, A. Makankin, V.V. Mitsyn, P. Moisenz, E. Nikonov,D. Oleynik, V. Palichik, V. Perelygin, A. Petrosyan, R. Semenov, S. Shmatov, V. Smirnov,D. Smolin, E. Tikhonenko, S. Vasil’ev, A. Vishnevskiy, A. Volodko, A. Zarubin, V. Zhiltsov
Petersburg Nuclear Physics Institute, Gatchina (St Petersburg), RussiaN. Bondar, L. Chtchipounov, A. Denisov, Y. Gavrikov, G. Gavrilov, V. Golovtsov, Y. Ivanov,V. Kim, V. Kozlov, P. Levchenko, G. Obrant, E. Orishchin, A. Petrunin, Y. Shcheglov, A. Shchet-kovskiy, V. Sknar, I. Smirnov, V. Sulimov, V. Tarakanov, L. Uvarov, S. Vavilov, G. Velichko,S. Volkov, A. Vorobyev
Institute for Nuclear Research, Moscow, RussiaYu. Andreev, A. Anisimov, P. Antipov, A. Dermenev, S. Gninenko, N. Golubev, M. Kirsanov,N. Krasnikov, V. Matveev, A. Pashenkov, V.E. Postoev, A. Solovey, A. Solovey, A. Toropin,S. Troitsky
Institute for Theoretical and Experimental Physics, Moscow, RussiaA. Baud, V. Epshteyn, V. Gavrilov, N. Ilina, V. Kaftanov†, V. Kolosov, M. Kossov1, A. Krokhotin,S. Kuleshov, A. Oulianov, G. Safronov, S. Semenov, I. Shreyber, V. Stolin, E. Vlasov, A. Zhokin
Moscow State University, Moscow, RussiaE. Boos, M. Dubinin17, L. Dudko, A. Ershov, A. Gribushin, V. Klyukhin, O. Kodolova, I. Lokhtin,S. Petrushanko, L. Sarycheva, V. Savrin, A. Snigirev, I. Vardanyan
26 A The CMS Collaboration
P.N. Lebedev Physical Institute, Moscow, RussiaI. Dremin, M. Kirakosyan, N. Konovalova, S.V. Rusakov, A. Vinogradov
State Research Center of Russian Federation, Institute for High Energy Physics, Protvino,RussiaS. Akimenko, A. Artamonov, I. Azhgirey, S. Bitioukov, V. Burtovoy, V. Grishin1, V. Kachanov,D. Konstantinov, V. Krychkine, A. Levine, I. Lobov, V. Lukanin, Y. Mel’nik, V. Petrov, R. Ryutin,S. Slabospitsky, A. Sobol, A. Sytine, L. Tourtchanovitch, S. Troshin, N. Tyurin, A. Uzunian,A. Volkov
Vinca Institute of Nuclear Sciences, Belgrade, SerbiaP. Adzic, M. Djordjevic, D. Jovanovic18, D. Krpic18, D. Maletic, J. Puzovic18, N. Smiljkovic
Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT),Madrid, SpainM. Aguilar-Benitez, J. Alberdi, J. Alcaraz Maestre, P. Arce, J.M. Barcala, C. Battilana, C. BurgosLazaro, J. Caballero Bejar, E. Calvo, M. Cardenas Montes, M. Cepeda, M. Cerrada, M. ChamizoLlatas, F. Clemente, N. Colino, M. Daniel, B. De La Cruz, A. Delgado Peris, C. Diez Pardos,C. Fernandez Bedoya, J.P. Fernandez Ramos, A. Ferrando, J. Flix, M.C. Fouz, P. Garcia-Abia,A.C. Garcia-Bonilla, O. Gonzalez Lopez, S. Goy Lopez, J.M. Hernandez, M.I. Josa, J. Marin,G. Merino, J. Molina, A. Molinero, J.J. Navarrete, J.C. Oller, J. Puerta Pelayo, L. Romero,J. Santaolalla, C. Villanueva Munoz, C. Willmott, C. Yuste
Universidad Autonoma de Madrid, Madrid, SpainC. Albajar, M. Blanco Otano, J.F. de Troconiz, A. Garcia Raboso, J.O. Lopez Berengueres
Universidad de Oviedo, Oviedo, SpainJ. Cuevas, J. Fernandez Menendez, I. Gonzalez Caballero, L. Lloret Iglesias, H. Naves Sordo,J.M. Vizan Garcia
Instituto de Fısica de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, SpainI.J. Cabrillo, A. Calderon, S.H. Chuang, I. Diaz Merino, C. Diez Gonzalez, J. Duarte Campder-ros, M. Fernandez, G. Gomez, J. Gonzalez Sanchez, R. Gonzalez Suarez, C. Jorda, P. LobellePardo, A. Lopez Virto, J. Marco, R. Marco, C. Martinez Rivero, P. Martinez Ruiz del Arbol,F. Matorras, T. Rodrigo, A. Ruiz Jimeno, L. Scodellaro, M. Sobron Sanudo, I. Vila, R. VilarCortabitarte
CERN, European Organization for Nuclear Research, Geneva, SwitzerlandD. Abbaneo, E. Albert, M. Alidra, S. Ashby, E. Auffray, J. Baechler, P. Baillon, A.H. Ball,S.L. Bally, D. Barney, F. Beaudette19, R. Bellan, D. Benedetti, G. Benelli, C. Bernet, P. Bloch,S. Bolognesi, M. Bona, J. Bos, N. Bourgeois, T. Bourrel, H. Breuker, K. Bunkowski, D. Campi,T. Camporesi, E. Cano, A. Cattai, J.P. Chatelain, M. Chauvey, T. Christiansen, J.A. CoarasaPerez, A. Conde Garcia, R. Covarelli, B. Cure, A. De Roeck, V. Delachenal, D. Deyrail, S. DiVincenzo20, S. Dos Santos, T. Dupont, L.M. Edera, A. Elliott-Peisert, M. Eppard, M. Favre,N. Frank, W. Funk, A. Gaddi, M. Gastal, M. Gateau, H. Gerwig, D. Gigi, K. Gill, D. Giordano,J.P. Girod, F. Glege, R. Gomez-Reino Garrido, R. Goudard, S. Gowdy, R. Guida, L. Guiducci,J. Gutleber, M. Hansen, C. Hartl, J. Harvey, B. Hegner, H.F. Hoffmann, A. Holzner, A. Honma,M. Huhtinen, V. Innocente, P. Janot, G. Le Godec, P. Lecoq, C. Leonidopoulos, R. Loos,C. Lourenco, A. Lyonnet, A. Macpherson, N. Magini, J.D. Maillefaud, G. Maire, T. Maki,L. Malgeri, M. Mannelli, L. Masetti, F. Meijers, P. Meridiani, S. Mersi, E. Meschi, A. MeynetCordonnier, R. Moser, M. Mulders, J. Mulon, M. Noy, A. Oh, G. Olesen, A. Onnela, T. Orimoto,L. Orsini, E. Perez, G. Perinic, J.F. Pernot, P. Petagna, P. Petiot, A. Petrilli, A. Pfeiffer, M. Pierini,M. Pimia, R. Pintus, B. Pirollet, H. Postema, A. Racz, S. Ravat, S.B. Rew, J. Rodrigues Antunes,
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G. Rolandi21, M. Rovere, V. Ryjov, H. Sakulin, D. Samyn, H. Sauce, C. Schafer, W.D. Schlatter,M. Schroder, C. Schwick, A. Sciaba, I. Segoni, A. Sharma, N. Siegrist, P. Siegrist, N. Sinanis,T. Sobrier, P. Sphicas22, D. Spiga, M. Spiropulu17, F. Stockli, P. Traczyk, P. Tropea, J. Troska,A. Tsirou, L. Veillet, G.I. Veres, M. Voutilainen, P. Wertelaers, M. Zanetti
Paul Scherrer Institut, Villigen, SwitzerlandW. Bertl, K. Deiters, W. Erdmann, K. Gabathuler, R. Horisberger, Q. Ingram, H.C. Kaestli,S. Konig, D. Kotlinski, U. Langenegger, F. Meier, D. Renker, T. Rohe, J. Sibille23,A. Starodumov24
Institute for Particle Physics, ETH Zurich, Zurich, SwitzerlandB. Betev, L. Caminada25, Z. Chen, S. Cittolin, D.R. Da Silva Di Calafiori, S. Dambach25,G. Dissertori, M. Dittmar, C. Eggel25, J. Eugster, G. Faber, K. Freudenreich, C. Grab, A. Herve,W. Hintz, P. Lecomte, P.D. Luckey, W. Lustermann, C. Marchica25, P. Milenovic26, F. Moort-gat, A. Nardulli, F. Nessi-Tedaldi, L. Pape, F. Pauss, T. Punz, A. Rizzi, F.J. Ronga, L. Sala,A.K. Sanchez, M.-C. Sawley, V. Sordini, B. Stieger, L. Tauscher†, A. Thea, K. Theofilatos,D. Treille, P. Trub25, M. Weber, L. Wehrli, J. Weng, S. Zelepoukine27
Universitat Zurich, Zurich, SwitzerlandC. Amsler, V. Chiochia, S. De Visscher, C. Regenfus, P. Robmann, T. Rommerskirchen,A. Schmidt, D. Tsirigkas, L. Wilke
National Central University, Chung-Li, TaiwanY.H. Chang, E.A. Chen, W.T. Chen, A. Go, C.M. Kuo, S.W. Li, W. Lin
National Taiwan University (NTU), Taipei, TaiwanP. Bartalini, P. Chang, Y. Chao, K.F. Chen, W.-S. Hou, Y. Hsiung, Y.J. Lei, S.W. Lin, R.-S. Lu,J. Schumann, J.G. Shiu, Y.M. Tzeng, K. Ueno, Y. Velikzhanin, C.C. Wang, M. Wang
Cukurova University, Adana, TurkeyA. Adiguzel, A. Ayhan, A. Azman Gokce, M.N. Bakirci, S. Cerci, I. Dumanoglu, E. Eskut,S. Girgis, E. Gurpinar, I. Hos, T. Karaman, T. Karaman, A. Kayis Topaksu, P. Kurt, G. Onengut,G. Onengut Gokbulut, K. Ozdemir, S. Ozturk, A. Polatoz, K. Sogut28, B. Tali, H. Topakli,D. Uzun, L.N. Vergili, M. Vergili
Middle East Technical University, Physics Department, Ankara, TurkeyI.V. Akin, T. Aliev, S. Bilmis, M. Deniz, H. Gamsizkan, A.M. Guler, K. Ocalan, M. Serin, R. Sever,U.E. Surat, M. Zeyrek
Bogazici University, Department of Physics, Istanbul, TurkeyM. Deliomeroglu, D. Demir29, E. Gulmez, A. Halu, B. Isildak, M. Kaya30, O. Kaya30, S. Ozkoru-cuklu31, N. Sonmez32
National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, UkraineL. Levchuk, S. Lukyanenko, D. Soroka, S. Zub
University of Bristol, Bristol, United KingdomF. Bostock, J.J. Brooke, T.L. Cheng, D. Cussans, R. Frazier, J. Goldstein, N. Grant,M. Hansen, G.P. Heath, H.F. Heath, C. Hill, B. Huckvale, J. Jackson, C.K. Mackay, S. Metson,D.M. Newbold33, K. Nirunpong, V.J. Smith, J. Velthuis, R. Walton
Rutherford Appleton Laboratory, Didcot, United KingdomK.W. Bell, C. Brew, R.M. Brown, B. Camanzi, D.J.A. Cockerill, J.A. Coughlan, N.I. Geddes,K. Harder, S. Harper, B.W. Kennedy, P. Murray, C.H. Shepherd-Themistocleous, I.R. Tomalin,J.H. Williams†, W.J. Womersley, S.D. Worm
28 A The CMS Collaboration
Imperial College, University of London, London, United KingdomR. Bainbridge, G. Ball, J. Ballin, R. Beuselinck, O. Buchmuller, D. Colling, N. Cripps, G. Davies,M. Della Negra, C. Foudas, J. Fulcher, D. Futyan, G. Hall, J. Hays, G. Iles, G. Karapos-toli, B.C. MacEvoy, A.-M. Magnan, J. Marrouche, J. Nash, A. Nikitenko24, A. Papageorgiou,M. Pesaresi, K. Petridis, M. Pioppi34, D.M. Raymond, N. Rompotis, A. Rose, M.J. Ryan,C. Seez, P. Sharp, G. Sidiropoulos1, M. Stettler, M. Stoye, M. Takahashi, A. Tapper, C. Timlin,S. Tourneur, M. Vazquez Acosta, T. Virdee1, S. Wakefield, D. Wardrope, T. Whyntie, M. Wing-ham
Brunel University, Uxbridge, United KingdomJ.E. Cole, I. Goitom, P.R. Hobson, A. Khan, P. Kyberd, D. Leslie, C. Munro, I.D. Reid,C. Siamitros, R. Taylor, L. Teodorescu, I. Yaselli
Boston University, Boston, USAT. Bose, M. Carleton, E. Hazen, A.H. Heering, A. Heister, J. St. John, P. Lawson, D. Lazic,D. Osborne, J. Rohlf, L. Sulak, S. Wu
Brown University, Providence, USAJ. Andrea, A. Avetisyan, S. Bhattacharya, J.P. Chou, D. Cutts, S. Esen, G. Kukartsev, G. Lands-berg, M. Narain, D. Nguyen, T. Speer, K.V. Tsang
University of California, Davis, Davis, USAR. Breedon, M. Calderon De La Barca Sanchez, M. Case, D. Cebra, M. Chertok, J. Conway,P.T. Cox, J. Dolen, R. Erbacher, E. Friis, W. Ko, A. Kopecky, R. Lander, A. Lister, H. Liu,S. Maruyama, T. Miceli, M. Nikolic, D. Pellett, J. Robles, M. Searle, J. Smith, M. Squires, J. Stilley,M. Tripathi, R. Vasquez Sierra, C. Veelken
University of California, Los Angeles, Los Angeles, USAV. Andreev, K. Arisaka, D. Cline, R. Cousins, S. Erhan1, J. Hauser, M. Ignatenko, C. Jarvis,J. Mumford, C. Plager, G. Rakness, P. Schlein†, J. Tucker, V. Valuev, R. Wallny, X. Yang
University of California, Riverside, Riverside, USAJ. Babb, M. Bose, A. Chandra, R. Clare, J.A. Ellison, J.W. Gary, G. Hanson, G.Y. Jeng, S.C. Kao,F. Liu, H. Liu, A. Luthra, H. Nguyen, G. Pasztor35, A. Satpathy, B.C. Shen†, R. Stringer, J. Sturdy,V. Sytnik, R. Wilken, S. Wimpenny
University of California, San Diego, La Jolla, USAJ.G. Branson, E. Dusinberre, D. Evans, F. Golf, R. Kelley, M. Lebourgeois, J. Letts, E. Lipeles,B. Mangano, J. Muelmenstaedt, M. Norman, S. Padhi, A. Petrucci, H. Pi, M. Pieri, R. Ranieri,M. Sani, V. Sharma, S. Simon, F. Wurthwein, A. Yagil
University of California, Santa Barbara, Santa Barbara, USAC. Campagnari, M. D’Alfonso, T. Danielson, J. Garberson, J. Incandela, C. Justus, P. Kalavase,S.A. Koay, D. Kovalskyi, V. Krutelyov, J. Lamb, S. Lowette, V. Pavlunin, F. Rebassoo, J. Ribnik,J. Richman, R. Rossin, D. Stuart, W. To, J.R. Vlimant, M. Witherell
California Institute of Technology, Pasadena, USAA. Apresyan, A. Bornheim, J. Bunn, M. Chiorboli, M. Gataullin, D. Kcira, V. Litvine, Y. Ma,H.B. Newman, C. Rogan, V. Timciuc, J. Veverka, R. Wilkinson, Y. Yang, L. Zhang, K. Zhu,R.Y. Zhu
Carnegie Mellon University, Pittsburgh, USAB. Akgun, R. Carroll, T. Ferguson, D.W. Jang, S.Y. Jun, M. Paulini, J. Russ, N. Terentyev,H. Vogel, I. Vorobiev
29
University of Colorado at Boulder, Boulder, USAJ.P. Cumalat, M.E. Dinardo, B.R. Drell, W.T. Ford, B. Heyburn, E. Luiggi Lopez, U. Nauenberg,K. Stenson, K. Ulmer, S.R. Wagner, S.L. Zang
Cornell University, Ithaca, USAL. Agostino, J. Alexander, F. Blekman, D. Cassel, A. Chatterjee, S. Das, L.K. Gibbons, B. Heltsley,W. Hopkins, A. Khukhunaishvili, B. Kreis, V. Kuznetsov, J.R. Patterson, D. Puigh, A. Ryd, X. Shi,S. Stroiney, W. Sun, W.D. Teo, J. Thom, J. Vaughan, Y. Weng, P. Wittich
Fairfield University, Fairfield, USAC.P. Beetz, G. Cirino, C. Sanzeni, D. Winn
Fermi National Accelerator Laboratory, Batavia, USAS. Abdullin, M.A. Afaq1, M. Albrow, B. Ananthan, G. Apollinari, M. Atac, W. Badgett, L. Bagby,J.A. Bakken, B. Baldin, S. Banerjee, K. Banicz, L.A.T. Bauerdick, A. Beretvas, J. Berryhill,P.C. Bhat, K. Biery, M. Binkley, I. Bloch, F. Borcherding, A.M. Brett, K. Burkett, J.N. Butler,V. Chetluru, H.W.K. Cheung, F. Chlebana, I. Churin, S. Cihangir, M. Crawford, W. Dagenhart,M. Demarteau, G. Derylo, D. Dykstra, D.P. Eartly, J.E. Elias, V.D. Elvira, D. Evans, L. Feng,M. Fischler, I. Fisk, S. Foulkes, J. Freeman, P. Gartung, E. Gottschalk, T. Grassi, D. Green,Y. Guo, O. Gutsche, A. Hahn, J. Hanlon, R.M. Harris, B. Holzman, J. Howell, D. Hufnagel,E. James, H. Jensen, M. Johnson, C.D. Jones, U. Joshi, E. Juska, J. Kaiser, B. Klima, S. Kossiakov,K. Kousouris, S. Kwan, C.M. Lei, P. Limon, J.A. Lopez Perez, S. Los, L. Lueking, G. Lukhanin,S. Lusin1, J. Lykken, K. Maeshima, J.M. Marraffino, D. Mason, P. McBride, T. Miao, K. Mishra,S. Moccia, R. Mommsen, S. Mrenna, A.S. Muhammad, C. Newman-Holmes, C. Noeding,V. O’Dell, O. Prokofyev, R. Rivera, C.H. Rivetta, A. Ronzhin, P. Rossman, S. Ryu, V. Sekhri,E. Sexton-Kennedy, I. Sfiligoi, S. Sharma, T.M. Shaw, D. Shpakov, E. Skup, R.P. Smith†, A. Soha,W.J. Spalding, L. Spiegel, I. Suzuki, P. Tan, W. Tanenbaum, S. Tkaczyk1, R. Trentadue1, L. Up-legger, E.W. Vaandering, R. Vidal, J. Whitmore, E. Wicklund, W. Wu, J. Yarba, F. Yumiceva,J.C. Yun
University of Florida, Gainesville, USAD. Acosta, P. Avery, V. Barashko, D. Bourilkov, M. Chen, G.P. Di Giovanni, D. Dobur,A. Drozdetskiy, R.D. Field, Y. Fu, I.K. Furic, J. Gartner, D. Holmes, B. Kim, S. Klimenko,J. Konigsberg, A. Korytov, K. Kotov, A. Kropivnitskaya, T. Kypreos, A. Madorsky, K. Matchev,G. Mitselmakher, Y. Pakhotin, J. Piedra Gomez, C. Prescott, V. Rapsevicius, R. Remington,M. Schmitt, B. Scurlock, D. Wang, J. Yelton
Florida International University, Miami, USAC. Ceron, V. Gaultney, L. Kramer, L.M. Lebolo, S. Linn, P. Markowitz, G. Martinez, J.L. Ro-driguez
Florida State University, Tallahassee, USAT. Adams, A. Askew, H. Baer, M. Bertoldi, J. Chen, W.G.D. Dharmaratna, S.V. Gleyzer, J. Haas,S. Hagopian, V. Hagopian, M. Jenkins, K.F. Johnson, E. Prettner, H. Prosper, S. Sekmen
Florida Institute of Technology, Melbourne, USAM.M. Baarmand, S. Guragain, M. Hohlmann, H. Kalakhety, H. Mermerkaya, R. Ralich, I. Vo-dopiyanov
University of Illinois at Chicago (UIC), Chicago, USAB. Abelev, M.R. Adams, I.M. Anghel, L. Apanasevich, V.E. Bazterra, R.R. Betts, J. Callner,M.A. Castro, R. Cavanaugh, C. Dragoiu, E.J. Garcia-Solis, C.E. Gerber, D.J. Hofman, S. Kha-latian, C. Mironov, E. Shabalina, A. Smoron, N. Varelas
30 A The CMS Collaboration
The University of Iowa, Iowa City, USAU. Akgun, E.A. Albayrak, A.S. Ayan, B. Bilki, R. Briggs, K. Cankocak36, K. Chung, W. Clarida,P. Debbins, F. Duru, F.D. Ingram, C.K. Lae, E. McCliment, J.-P. Merlo, A. Mestvirishvili,M.J. Miller, A. Moeller, J. Nachtman, C.R. Newsom, E. Norbeck, J. Olson, Y. Onel, F. Ozok,J. Parsons, I. Schmidt, S. Sen, J. Wetzel, T. Yetkin, K. Yi
Johns Hopkins University, Baltimore, USAB.A. Barnett, B. Blumenfeld, A. Bonato, C.Y. Chien, D. Fehling, G. Giurgiu, A.V. Gritsan,Z.J. Guo, P. Maksimovic, S. Rappoccio, M. Swartz, N.V. Tran, Y. Zhang
The University of Kansas, Lawrence, USAP. Baringer, A. Bean, O. Grachov, M. Murray, V. Radicci, S. Sanders, J.S. Wood, V. Zhukova
Kansas State University, Manhattan, USAD. Bandurin, T. Bolton, K. Kaadze, A. Liu, Y. Maravin, D. Onoprienko, I. Svintradze, Z. Wan
Lawrence Livermore National Laboratory, Livermore, USAJ. Gronberg, J. Hollar, D. Lange, D. Wright
University of Maryland, College Park, USAD. Baden, R. Bard, M. Boutemeur, S.C. Eno, D. Ferencek, N.J. Hadley, R.G. Kellogg, M. Kirn,S. Kunori, K. Rossato, P. Rumerio, F. Santanastasio, A. Skuja, J. Temple, M.B. Tonjes, S.C. Ton-war, T. Toole, E. Twedt
Massachusetts Institute of Technology, Cambridge, USAB. Alver, G. Bauer, J. Bendavid, W. Busza, E. Butz, I.A. Cali, M. Chan, D. D’Enterria, P. Everaerts,G. Gomez Ceballos, K.A. Hahn, P. Harris, S. Jaditz, Y. Kim, M. Klute, Y.-J. Lee, W. Li, C. Loizides,T. Ma, M. Miller, S. Nahn, C. Paus, C. Roland, G. Roland, M. Rudolph, G. Stephans, K. Sumorok,K. Sung, S. Vaurynovich, E.A. Wenger, B. Wyslouch, S. Xie, Y. Yilmaz, A.S. Yoon
University of Minnesota, Minneapolis, USAD. Bailleux, S.I. Cooper, P. Cushman, B. Dahmes, A. De Benedetti, A. Dolgopolov, P.R. Dudero,R. Egeland, G. Franzoni, J. Haupt, A. Inyakin37, K. Klapoetke, Y. Kubota, J. Mans, N. Mirman,D. Petyt, V. Rekovic, R. Rusack, M. Schroeder, A. Singovsky, J. Zhang
University of Mississippi, University, USAL.M. Cremaldi, R. Godang, R. Kroeger, L. Perera, R. Rahmat, D.A. Sanders, P. Sonnek, D. Sum-mers
University of Nebraska-Lincoln, Lincoln, USAK. Bloom, B. Bockelman, S. Bose, J. Butt, D.R. Claes, A. Dominguez, M. Eads, J. Keller, T. Kelly,I. Kravchenko, J. Lazo-Flores, C. Lundstedt, H. Malbouisson, S. Malik, G.R. Snow
State University of New York at Buffalo, Buffalo, USAU. Baur, I. Iashvili, A. Kharchilava, A. Kumar, K. Smith, M. Strang
Northeastern University, Boston, USAG. Alverson, E. Barberis, O. Boeriu, G. Eulisse, G. Govi, T. McCauley, Y. Musienko38, S. Muzaf-far, I. Osborne, T. Paul, S. Reucroft, J. Swain, L. Taylor, L. Tuura
Northwestern University, Evanston, USAA. Anastassov, B. Gobbi, A. Kubik, R.A. Ofierzynski, A. Pozdnyakov, M. Schmitt, S. Stoynev,M. Velasco, S. Won
University of Notre Dame, Notre Dame, USAL. Antonelli, D. Berry, M. Hildreth, C. Jessop, D.J. Karmgard, T. Kolberg, K. Lannon, S. Lynch,
31
N. Marinelli, D.M. Morse, R. Ruchti, J. Slaunwhite, J. Warchol, M. Wayne
The Ohio State University, Columbus, USAB. Bylsma, L.S. Durkin, J. Gilmore39, J. Gu, P. Killewald, T.Y. Ling, G. Williams
Princeton University, Princeton, USAN. Adam, E. Berry, P. Elmer, A. Garmash, D. Gerbaudo, V. Halyo, A. Hunt, J. Jones, E. Laird,D. Marlow, T. Medvedeva, M. Mooney, J. Olsen, P. Piroue, D. Stickland, C. Tully, J.S. Werner,T. Wildish, Z. Xie, A. Zuranski
University of Puerto Rico, Mayaguez, USAJ.G. Acosta, M. Bonnett Del Alamo, X.T. Huang, A. Lopez, H. Mendez, S. Oliveros, J.E. RamirezVargas, N. Santacruz, A. Zatzerklyany
Purdue University, West Lafayette, USAE. Alagoz, E. Antillon, V.E. Barnes, G. Bolla, D. Bortoletto, A. Everett, A.F. Garfinkel, Z. Gecse,L. Gutay, N. Ippolito, M. Jones, O. Koybasi, A.T. Laasanen, N. Leonardo, C. Liu, V. Maroussov,P. Merkel, D.H. Miller, N. Neumeister, A. Sedov, I. Shipsey, H.D. Yoo, Y. Zheng
Purdue University Calumet, Hammond, USAP. Jindal, N. Parashar
Rice University, Houston, USAV. Cuplov, K.M. Ecklund, F.J.M. Geurts, J.H. Liu, D. Maronde, M. Matveev, B.P. Padley,R. Redjimi, J. Roberts, L. Sabbatini, A. Tumanov
University of Rochester, Rochester, USAB. Betchart, A. Bodek, H. Budd, Y.S. Chung, P. de Barbaro, R. Demina, H. Flacher, Y. Gotra,A. Harel, S. Korjenevski, D.C. Miner, D. Orbaker, G. Petrillo, D. Vishnevskiy, M. Zielinski
The Rockefeller University, New York, USAA. Bhatti, L. Demortier, K. Goulianos, K. Hatakeyama, G. Lungu, C. Mesropian, M. Yan
Rutgers, the State University of New Jersey, Piscataway, USAO. Atramentov, E. Bartz, Y. Gershtein, E. Halkiadakis, D. Hits, A. Lath, K. Rose, S. Schnetzer,S. Somalwar, R. Stone, S. Thomas, T.L. Watts
University of Tennessee, Knoxville, USAG. Cerizza, M. Hollingsworth, S. Spanier, Z.C. Yang, A. York
Texas A&M University, College Station, USAJ. Asaadi, A. Aurisano, R. Eusebi, A. Golyash, A. Gurrola, T. Kamon, C.N. Nguyen, J. Pivarski,A. Safonov, S. Sengupta, D. Toback, M. Weinberger
Texas Tech University, Lubbock, USAN. Akchurin, L. Berntzon, K. Gumus, C. Jeong, H. Kim, S.W. Lee, S. Popescu, Y. Roh, A. Sill,I. Volobouev, E. Washington, R. Wigmans, E. Yazgan
Vanderbilt University, Nashville, USAD. Engh, C. Florez, W. Johns, S. Pathak, P. Sheldon
University of Virginia, Charlottesville, USAD. Andelin, M.W. Arenton, M. Balazs, S. Boutle, M. Buehler, S. Conetti, B. Cox, R. Hirosky,A. Ledovskoy, C. Neu, D. Phillips II, M. Ronquest, R. Yohay
Wayne State University, Detroit, USAS. Gollapinni, K. Gunthoti, R. Harr, P.E. Karchin, M. Mattson, A. Sakharov
32 A The CMS Collaboration
University of Wisconsin, Madison, USAM. Anderson, M. Bachtis, J.N. Bellinger, D. Carlsmith, I. Crotty1, S. Dasu, S. Dutta, J. Efron,F. Feyzi, K. Flood, L. Gray, K.S. Grogg, M. Grothe, R. Hall-Wilton1, M. Jaworski, P. Klabbers,J. Klukas, A. Lanaro, C. Lazaridis, J. Leonard, R. Loveless, M. Magrans de Abril, A. Mohapatra,G. Ott, G. Polese, D. Reeder, A. Savin, W.H. Smith, A. Sourkov40, J. Swanson, M. Weinberg,D. Wenman, M. Wensveen, A. White
†: Deceased1: Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland2: Also at Universidade Federal do ABC, Santo Andre, Brazil3: Also at Soltan Institute for Nuclear Studies, Warsaw, Poland4: Also at Universite de Haute-Alsace, Mulhouse, France5: Also at Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique desParticules (IN2P3), Villeurbanne, France6: Also at Moscow State University, Moscow, Russia7: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary8: Also at University of California, San Diego, La Jolla, USA9: Also at Tata Institute of Fundamental Research - HECR, Mumbai, India10: Also at University of Visva-Bharati, Santiniketan, India11: Also at Facolta’ Ingegneria Universita’ di Roma ”La Sapienza”, Roma, Italy12: Also at Universita della Basilicata, Potenza, Italy13: Also at Laboratori Nazionali di Legnaro dell’ INFN, Legnaro, Italy14: Also at Universita di Trento, Trento, Italy15: Also at ENEA - Casaccia Research Center, S. Maria di Galeria, Italy16: Also at Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland17: Also at California Institute of Technology, Pasadena, USA18: Also at Faculty of Physics of University of Belgrade, Belgrade, Serbia19: Also at Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France20: Also at Alstom Contracting, Geneve, Switzerland21: Also at Scuola Normale e Sezione dell’ INFN, Pisa, Italy22: Also at University of Athens, Athens, Greece23: Also at The University of Kansas, Lawrence, USA24: Also at Institute for Theoretical and Experimental Physics, Moscow, Russia25: Also at Paul Scherrer Institut, Villigen, Switzerland26: Also at Vinca Institute of Nuclear Sciences, Belgrade, Serbia27: Also at University of Wisconsin, Madison, USA28: Also at Mersin University, Mersin, Turkey29: Also at Izmir Institute of Technology, Izmir, Turkey30: Also at Kafkas University, Kars, Turkey31: Also at Suleyman Demirel University, Isparta, Turkey32: Also at Ege University, Izmir, Turkey33: Also at Rutherford Appleton Laboratory, Didcot, United Kingdom34: Also at INFN Sezione di Perugia; Universita di Perugia, Perugia, Italy35: Also at KFKI Research Institute for Particle and Nuclear Physics, Budapest, Hungary36: Also at Istanbul Technical University, Istanbul, Turkey37: Also at University of Minnesota, Minneapolis, USA38: Also at Institute for Nuclear Research, Moscow, Russia39: Also at Texas A&M University, College Station, USA40: Also at State Research Center of Russian Federation, Institute for High Energy Physics,Protvino, Russia
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