Constraining slepton and chargino through compressed top squark search

• Main Authors: Partha Konar, Tanmoy Mondal, Abhaya Kumar Swain
• Format: Article
• Language: English
• Published: SpringerOpen 2018-04-01
• Series: Journal of High Energy Physics
• Subjects: Supersymmetry Phenomenology
• Online Access: http://link.springer.com/article/10.1007/JHEP04(2018)024

Abstract We examine the compressed mass spectrum with sub-TeV top squark t˜ $$ \left(\tilde{t}\right) $$ as lightest colored (s)particle in natural supersymmetry (SUSY). Such spectra are searched along with an additional hard jet, not only to boost the soft decay particles, also to yield enough missing transverse momentum. Several interesting kinematic variables are proposed to improve the probe performance for this difficult region, where we concentrate on relatively clean dileptonic channel of the top squark decaying into lightest neutralino (χ10), which is also the lightest supersymmetric particle. In this work, we investigate the merit of these kinematic variables, sensitive to compressed mass region extending the search by introducing additional states, chargino and slepton (sneutrino) having masses in between the t˜ $$ \tilde{t} $$ and χ10. Enhanced production and lack of branching suppression are capable of providing a strong limit on chargino and slepton/sneutrino mass along with top squark mass. We perform a detailed collider analysis using simplified SUSY spectrum and found that with the present LHC data Mt˜ $$ {M}_{\tilde{t}} $$ can be excluded up to 710 GeV right away for Mχ10 $$ {M}_{\upchi_1^0} $$ of 640 GeV for a particular mass gap between different states.