Search for contact interactions using the inclusive jet $P_{T}$ spectrum in PP collisions st $\sqrt{s}$= 7 TEV

We report results of a search for a deviation in the jet production cross section from theprediction of perturbative quantum chromodynamics at next-to-leading order. The searchis conducted using a 7 TeV proton-proton data sample corresponding to an integratedluminosity of 5.0 fb−1 , collected with the Compact Muon Solenoid detector at the LargeHadron Collider. A deviation could arise from interactions characterized by a mass scaleΛ too high to be probed directly at the LHC. Such phenomena can be modeled as contactinteractions. No evidence of a deviation is found. Using a Bayesian method lower limits areset on Λ of 10.1 TeV and 14.1 TeV at 95% confidence level for models with destructive andconstructive interference, respectively.hierarchy, is located away from CERN. The 7 Tier-1 sites archive the LHC proton-protoncollision data that is initially processed at CERN. These sites provide access to all recordedand simulated data for the Tier-2 sites, via wide-area network (WAN) transfers. All centraldata processing workflows are executed at the Tier-1 level, which contain re-reconstructionand skimming workflows of collision data as well as reprocessing of simulated data to adaptto changing detector conditions. This paper describes the operation of the CMS processinginfrastructure at the Tier-1 level. The Tier-1 workflows are described in detail. The operationaloptimization of resource usage is described. In particular, the variation of different workflowsduring the data taking period of 2010, their efficiencies and latencies as well as their impacton the delivery of physics results is discussed and lessons are drawn from this experience. Thesimulation of proton-proton collisions for the CMS experiment is primarily carried out at thesecond tier of the CMS computing infrastructure. Half of the Tier-2 sites of CMS are reservedfor central Monte Carlo (MC) production while the other half is available for user analysis. Thispaper summarizes the large throughput of the MC production operation during the data takingperiod of 2010 and discusses the latencies and efficiencies of the various types of MC productionworkflows. We present the operational procedures to optimize the usage of available resourcesand we the operational model of CMS for including opportunistic resources, such as the largerTier-3 sites, into the central production operation.We present the results of an experiment that measured the response of silicon photomultiplier (SiPM)devices to minimum ionizing particles (MIPs). The SiPMs are proposed as replacements for the hybridphotodiodes (HPDs) of the Compact Muon Solenoid (CMS) Hadron Outer (HO) Calorimeter in the2010-2011 upgrade. The experiment was performed as part of the HCAL Test Beam in July 2009at CERN. The emphasis was on the investigation of the potential for an unexpected response from aMIP, which might result in a large spurious signal. We tested a new type of SiPM device, a micropixel avalanche photodiode (MAPD) manufactured by Zecotek, and found that a MIP typically fired asingle pixel. The MIP interaction with the MAPD would fire two and sometimes three pixels, howeverwith a lower rate.