Sparticles in Motion - getting to the line in compressed scenarios with the Recursive Jigsaw Reconstruction

TL;DR

This paper introduces a novel analysis technique based on Recursive Jigsaw Reconstruction to improve the detection of compressed supersymmetric scenarios with small mass splittings, by decomposing events into observables that exploit initial state radiation.

Contribution

The paper develops a new set of kinematic observables using Recursive Jigsaw Reconstruction tailored for compressed supersymmetry searches, enhancing sensitivity to low-momentum decay products.

Findings

Effective in identifying compressed spectra with small mass splittings

Improves discrimination of signal from background in hadronic final states

Demonstrates potential for better detection of squark and gluino production

Abstract

The observation of light super-partners from a supersymmetric extension to the Standard Model is an intensely sought-after experimental outcome, providing an explanation for the stabilization of the electroweak scale and indicating the existence of new particles which could be consistent with dark matter phenomenology. For compressed scenarios, where sparticle spectra mass-splittings are small and decay products carry low momenta, dedicated techniques are required in all searches for supersymmetry. In this paper we suggest an approach for these analyses based on the concept of Recursive Jigsaw Reconstruction, decomposing each event into a basis of complementary observables, for cases where strong initial state radiation has sufficient transverse momentum to elicit the recoil of any final state sparticles. We introduce a collection of kinematic observables which can be used to probe compressed scenarios, in particular exploiting the correlation between missing momentum and that of radiative jets. As an example, we study squark and gluino production, focusing on mass-splittings between parent super-particles and their lightest decay products between 25 and 200 GeV, in hadronic final states where there is an ambiguity in the provenance of reconstructed jets.