Tagging a mono-top signature in Natural SUSY

Abstract

We study the feasibility of probing a region of Natural Supersymmetry where the stop and higgsino masses are compressed. Although this region is most effectively searched for in the mono-jet channel, this signature is present in many other non-supersymmetric frameworks. Therefore, another channel that carries orthogonal information is required to confirm the existence of the light stop and higgsinos. We show that a supersymmetric version of the $t\bar{t}H$ process, $pp\to t{\tilde{t}}_1{\tilde{\chi }}_{1(2)}^0$, can have observably large rate when both the stop and higgsinos are significantly light, and it leads to a distinctive mono-top signature in the compressed mass region. We demonstrate that the hadronic channel of the mono-top signature can effectively discriminate the signal from backgrounds by tagging a hadronic top-jet. We show that the hadronic channel of mono-top signature offers a significant improvement over the leptonic channel and the sensitivity reaches $m_{{\tilde{t}}_1}\simeq 420$ GeV at the 13 TeV LHC with 3 ab${}^{-1}$ luminosity.

Comments: 7 pages, 7 figures and 1 table