Measuring the masses of a pair of semi-invisibly decaying particles in central exclusive production with forward proton tagging

TL;DR

This paper proposes an improved method for measuring the masses of new particles in central exclusive production by utilizing mass-shell constraints, achieving a few GeV accuracy with about 30 events.

Contribution

It introduces a novel approach that enhances mass measurement precision in CEP by fully exploiting mass-shell constraints, applicable to particles like sleptons and neutralinos.

Findings

Masses of slepton and neutralino can be measured with a few GeV accuracy.

The method requires around 30 signal events for effective measurement.

Full use of mass-shell constraints improves existing CEP mass measurement strategies.

Abstract

We discuss how the mass of new physics particles involved in a pair of short decay chains leading to two invisible particles, for example slepton pair production, followed by the decay into two leptons and two neutralinos, may be measured in central exclusive production (CEP) with forward proton tagging. We show how the existing mass measurement strategies in CEP may be improved by making full use of the mass-shell constraints, and demonstrate that, with around 30 signal events, the masses of the slepton and neutralino can be measured with an accuracy of a few GeV.