On the ATLAS top mass measurements and the potential for stealth stop contamination

Journal of High Energy Physics

Peter Zheng¹  Stephanie Majewski¹  Timothy Cohen¹  Bryan Ostdiek² 

[1] Institute for Fundamental Science, Department of Physics, University of Oregon, 1371 E 13th Avenue, 97403, Eugene, OR, USA;Institute for Fundamental Science, Department of Physics, University of Oregon, 1371 E 13th Avenue, 97403, Eugene, OR, USA;Department of Physics, Harvard University, 17 Oxford Street, 02138, Cambridge, MA, USA;

关键词: Hadron-Hadron scattering (experiments);    Top physics;    top squark;   

DOI  :  10.1007/JHEP06(2020)019

来源: Springer

【 摘 要 】

The discovery of the stop — the Supersymmetric partner of the top quark — is a key goal of the physics program enabled by the Large Hadron Collider. Although much of the accessible parameter space has already been probed, all current searches assume the top mass is known. This is relevant for the “stealth stop” regime, which is characterized by decay kinematics that force the final state top quark off its mass shell; such decays would contaminate the top mass measurements. We investigate the resulting bias imparted to the template method based ATLAS approach. A careful recasting of these results shows that effect can be as large as 2.0 GeV, comparable to the current quoted uncertainty on the top mass. Thus, a robust exploration of the stealth stop splinter requires the simultaneous consideration of the impact on the top mass. Additionally, we explore the robustness of the template technique, and point out a simple strategy for improving the methodology implemented for the semi-leptonic channel.

【 授权许可】

Unknown