Search for Large Spatial Extra Dimensions with Dimuon Events from 7 TeV pp collisions at CMS

Data recorded by the CMS (Compact Muon Solenoid) experiment is analyzed to study theproduction of high-mass muon pairs in proton-proton collisions at the LHC (Large HadronCollider). Most of the presented results are based on a dataset of 5.3 fb−1 at a center-of-mass√energy of s = 7 TeV. The interpretation of the measured dimuon mass spectrum focuseson a potential non-resonant signal from s-channel graviton exchange. Such a signature of newphysics is motivated by the ADD (Arkani-Hamed, Dimopoulos, Dvali) model of large spatialextra dimensions.The main background for the search is given by the SM (Standard Model) prediction of¯neutral current Drell-Yan events. Other background sources like for example tt production arealso considered. The Standard Model expectation is evaluated based on simulation studies andcan be tested for dimuon masses below the signal region. Estimates of theory uncertainties onthe background prediction and uncertainties related to the detector performance are includedin the statistical evaluation of the measurement.The dimuon mass spectrum observed in the 2011 CMS dataset is found to be compatible withthe SM expectation. For masses greater than 1.3 TeV, signal cross sections of greater than0.84 fb−1 can be excluded at 95% confidence level. This result corresponds to an exclusion ofvalues below 3.0 TeV for the ADD model parameters ΛT . A combination of dimuon, dielectron and diphoton results based on a dataset of about 2.0 fb−1 extends the excluded range to√ΛT < 3.3 TeV. Also limits based on the 2012 CMS dataset at collision energies of s = 8 TeVand some aspects of the CMS search for new dilepton resonances are briefly discussed.