Search for pair production of first and second generation leptoquarks in proton-proton collisions ats=8  TeV

Abstract

A search for pair production of first and second generation leptoquarks is performed in final states containing either two charged leptons and two jets, or one charged lepton, one neutrino and two jets, using proton-proton collision data at ffiffi ffi s p ¼ 8 TeV. The data, corresponding to an integrated luminosity of 19.7 fb −1 , were recorded with the CMS detector at the LHC. First-generation scalar leptoquarks with masses less than 1010 (850) GeV are excluded for β ¼ 1.0 ð0.5Þ, where β is the branching fraction of a leptoquark decaying to a charged lepton and a quark. Similarly, second-generation scalar leptoquarks with masses less than 1080 (760) GeV are excluded for β ¼ 1.0 ð0.5Þ. Mass limits are also set for vector leptoquark production scenarios with anomalous vector couplings, and for R-parity violating supersymmetric scenarios of top squark pair production resulting in similar final-state signatures. These are the most stringent limits placed on the masses of vector leptoquarks and RPV top squarks to date.

Flavorful leptoquarks at hadron colliders

“…For instance, mass limits for leptoquarks decaying 50% to electrons (muons) plus jet and the other 50% to neutrinos and a jet are 900 GeV (850 GeV) [25], with similar results reported in [26,27], all obtained from pair production. The limits improve to 1100 GeV [26] (1080 GeV [27]) for 100% decay to electrons (muons) plus jet. Bounds from single production in jet ee (1755 GeV) and jet μμ (660 GeV) [28] assume 100% decays to charged leptons and coupling equal to one.…”

Non-standard interactions in radiative neutrino mass models

“…There are dedicated searches for pair production of first [180,181], second [181][182][183] and third generation [183][184][185] LQs at the LHC. Given the model Lagrangian 5.1, we are interested in the final states containing either two charged leptons and two jets ( jj), or two neutrinos and two jets (ννjj).…”

B s → μ + μ − as current and future probe of new physics

“…In the case of vector LQs, the angular distributions will be different, leading to slightly different acceptances. This effect has been found to be small in [79] and we will neglect it in the following. In our analysis we include the LQ searches from ATLAS [80,81] and CMS [82] using 8 TeV and 13 TeV data.…”