Resonant Slepton Production in the Two Muon + Jets Final State at $\sqrt{s}$ = 8 TeV

Presented is the search for resonant production of second generation sleptons in R-parity violating supersymmetry. It is performed using the integrated luminosity of L = 19.7 fb−1 of proton-proton collisions recorded by the CMS experiment at the LHC, CERN during 2012. The centre-of-mass energy during this period was set to √s = 8 TeV. The theoretical basis of this analysis is the cMSSM model, which limits the amount of free supersymmetric parameters to a manageable amount. As the commonly assumed R-parity is replaced by another discrete symmetry called “baryon triality”, additional parameters are available. To investigate the new lepton number violating Yukawa coupling λ′211, single coupling dominance for this parameter is assumed. As a consequence, production of a single second generation slepton through two first generation quarks becomes possible. The decay signature of the slepton includes two muons and two jets, of which the lepton charges have the distinct possibility to be of the same sign. This sets the final state apart from almost all StandardModelprocesses. Additionally, theamountofmissingtransverseenergyisquitelow, as all particles of the final state can be fully reconstructed. Several analysis requirements are designedaroundexploitingtheseattributes,whichresultsinthebackgroundbeingofthesame order of magnitude as the signal. A portion of the remaining background samples is replaced by a data-driven estimate to avoid dealing with difficult to simulate multi-jet processes in the final state. No significant deviation of the data from the background prediction can be observed and limits are set on λ′211 over a wide range of the m0-m1/2 phase space. They both expand the parameter coverage and improve the limits with respect to the 2011 analysis predecessor by roughly a factor of 2. A smuon mass of 1200 GeV is typical for the examined phase space and corresponds to a 95 % CL limit of λ′211 ≤ 8 · 10−3.