Demystifying the compressed top squark region with kinematic variables

TL;DR

This paper explores the use of specialized kinematic variables to improve the detection of compressed top squark scenarios in supersymmetry, extending current experimental limits.

Contribution

It introduces a novel search strategy utilizing kinematic variables tailored for compressed mass regions, enhancing sensitivity in dileptonic decay channels.

Findings

Effective background suppression from top quark processes

Extended exclusion limits in the compressed top squark mass region

Demonstrated feasibility of the proposed method with simulated data

Abstract

The ongoing perplexing scenario with no hints of new physics at the Large Hadron Collider can be elucidated amicably if the exotic particle spectrum in many of the well-motivated theoretical models possesses degenerate mass. We investigate the usefulness of different kinematic variables sensitive to the compressed mass region, and propose a search strategy considering a phenomenological supersymmetric scenario where the top squark undergoes a four-body decay due to its extremely narrow mass difference with the lightest supersymmetric particle. Considering a challenging but relatively clean dileptonic decay channel, we demonstrate that one can effectively restrain the significant background from the top quark, which provides a complementary approach to the present CMS analysis. With the new strategic approach the current limit can be extended to a phase-space region that was not explored before.