Accurate Mass Determinations in Decay Chains with Missing Energy: II

TL;DR

This paper introduces a kinematic method for accurately determining particle masses in decay chains with missing energy at hadron colliders, applicable across different models like SUSY and UED.

Contribution

It presents a detailed, model-independent procedure for mass determination in complex decay chains involving multiple visible and invisible particles.

Findings

Masses obtained are independent of the underlying model.

Method is demonstrated on Z -> 3 visible particles + N decay topology.

Applicable to SUSY and UED models.

Abstract

We discuss kinematic methods for determining the masses of the particles in events at a hadron collider in which a pair of identical particles is produced with each decaying via a series of on-shell intermediate beyond-the-SM (BSM) particles to visible SM particles and an invisible particle (schematically, pp -> ZZ + jets with Z -> Aa -> Bba -> Ccba -> ... -> cba... + N where a,b,c,... are visible SM particles or groups of SM particles, A,B,C,... are on-shell BSM particles and N is invisible). This topology arises in many models including SUSY processes such as squark and gluino pair production and decay. We present the detailed procedure for the case of Z -> 3 visible particles + N and demonstrate that the masses obtained from the kinematic procedure are independent of the model by comparing SUSY to UED.