Lepto-Quarks at ATLAS and CMS

by Carolina Deluca (NIKHEF (NL)), Yi Chen (California Institute of Technology (US))

Thursday 12 Apr 2012, 11:00 → 12:00 Europe/Zurich

4/2-011 - TH common room (CERN)

The results of a search for the production of first, second and third generation scalar leptoquarks are presented. Searches for the first two generations are presented by the ATLAS experiment for final states consisting of either two oppositely charged leptons and at least two jets or a charged lepton plus missing transverse momentum and at least two jets. The event yields in the signal regions are found to be consistent with the Standard Model background expectations. The production of first and second generation leptoquarks is excluded for leptoquark masses mLQ<660 (607) GeV and mLQ < 685 (594) GeV at 95% confidence level, respectively, for a branching ratio of 1.0 (0.5) for leptoquark decay to a charged lepton and a quark. A search for the third generation leptoquark is presented by the CMS experiment for final states containing two b-jets and large missing transverse momentum using the Razor technique with 1.8/fb of data at 7 TeV. Expectations from standard model background realso consistent with observed data. As there is no significant excess, a limit is set on 3rd generation leptoquark to exclude up to 350 GeV at 95% C.L. assuming branching ratio of 1.0 to b-jet and neutrino. The limit as a function of branching ratio is also provided.

ATLAS First Generation Leptoquarks https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2011-17/

ATLAS Second Generation Leptoquarks https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2011-26/

CMS PAS http://cdsweb.cern.ch/record/1416079?ln=en

CMS Public twiki https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsEXO11030

Paper http://arxiv.org/pdf/1112.4828v4.pdf http://arxiv.org/pdf/1203.3172v1.pdf