Mono-top Signature from Supersymmetric $t\bar{t}H$ Channel

Abstract

We point out that a distinctive mono-top signature is present in Natural SUSY scenarios when a scalar top-quark and higgsinos are almost mass degenerate. This signature originates from a supersymmetric counter part of the $t\bar{t}H$ process, i.e. $pp\to \tilde{t}t\tilde{h}$. Unlike mono-jet signatures exploiting initial state radiation, this channel can be regarded as a smoking gun signature of a light stop and higgsinos, allowing a direct probe of the stop and neutralino sectors. The production rate of this channel largely depends on the up-type higgsino components in the neutralinos while the stop sector is sensitive to angular distributions of top-quark's decay products. We develop an optimal search strategy to capture the supersymmetric $t\bar{t}H$ process and find that a high luminosity LHC can probe the stop and higgsino sectors with $m_{{\tilde{t}}_1}\lesssim 380$ GeV and $m_{{\tilde{t}}_1}-m_{{\tilde{\chi }}_1^0}\lesssim m_W$. Additionally, we propose a kinematic variable with which one can measure the stop mixing in this channel.

Comments: 22 pages, 11 Figures