Supersymmetric monojets at the Large Hadron Collider

Abstract

Supersymmetric monojets may be produced at the Large Hadron Collider by the process qg → q χ 0 1 → q χ 0 1 χ 0 1 , leading to a jet recoiling against missing transverse momentum. We discuss the feasibility and utility of the supersymmetric monojet signal. In particular, we examine the possible precision with which one can ascertain the χ 0 1 qq coupling via the rate for monojet events. Such a coupling contains information on the composition of the χ 0 1 and helps bound dark matter direct detection cross-sections and the dark matter relic density of the χ 0 1 . It also provides a check of the supersymmetric relation between gauge couplings and gaugino-quark-squark couplings.

Probing light higgsinos in natural SUSY from monojet signals at the LHC

“…An estimation of the QCD background based on the full detector simulation can be found in [34]. By fitting the jet energy response function (JERF) using the method in [35], the authors of [36] found that the multijet background in the supersymmetric monojets analysis at 14 TeV LHC can be reduced to a negligible level by requiring a large / E T cut, such as / E T > 200 GeV . Since other dominant backgrounds have / E T > 200 GeV, we set / E T > 500 GeV as in [37], where the cuts for the monojet events are optimized for 14 TeV LHC, thus we can safely neglect the QCD background in our calculation (the pile-up effects at 14 TeV HL-LHC have not been considered in the work, due to lack of the exact detector configurations.).…”

Light stop searches at the LHC in events with twobjets and missing energy

“…We neglect QCD dijet and trijet production in our analysis, since a large / E T cut should remove those backgrounds [32,36,37].…”

“…On the one hand, this cut increases the significance of the signal over the top, Zbb and W bb backgrounds. On the other hand, we expect that it suppresses pure QCD backgrounds like dijet and trijet production to a negligible level [32,36].…”

“…Therefore, the measurement of our process allows a test of the respective SUSY coupling relation and thus a test of supersymmetry itself [31,32]. Only a few of such tests have been proposed so far for the LHC [31][32][33] and none of them addresses interactions which originate from the superpotential.…”

Robustness of dark matter constraints and interplay with collider searches for New Physics

“…However, the simple description of dark matter production at the LHC based on a single mediator is not realistic with regard to concrete models such as the pMSSM, in which co-annihilations are favoured by the relic density constraints. Indeed, SUSY particles such as squarks or gluinos can be close in mass to the lightest neutralino, so that the production of two squarks or gluinos associated to a hard jet can still be seen as a monojet, because the jets produced in their decays would be soft enough to remain undetected [180][181][182][183][184]. In addition, several mediators can be involved.…”