Extracting MSSM Masses From Heavy Higgs Decays to Four Leptons at the LHC

TL;DR

This paper demonstrates that the LHC can accurately measure heavy Higgs and neutralino masses in the MSSM through invariant mass distributions in four-lepton decay channels, achieving about 30% precision.

Contribution

It introduces a novel method for measuring MSSM particle masses from heavy Higgs decays to four leptons at the LHC, with detailed Monte Carlo analysis.

Findings

LHC can measure Higgs and neutralino masses to ~30% accuracy.

If one mass is known within 5%, others can be measured more precisely.

First accurate measurement of H/A mass via invariant mass distribution techniques.

Abstract

It is well known that finding and measuring the masses of particles in the Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider (LHC) may be possible using invariant mass distributions in exclusive channels containing n_j jets and n_l leptons. We perform this analysis for the (n_j, n_l) = (0,4) decay of heavy Higgs bosons to neutralinos, pp \to H/A \to \chi_i \chi_j (i,j =2,3,4), which then decay to four leptons and two lightest neutralinos \chi_1 via on-shell sleptons. When i=j and the sleptons are degenerate, our Monte Carlo study shows that the LHC will be able to measure the Higgs and relevant neutralino and slepton masses to roughly 30%; however, if one of these is already known within 5%, the other three may be found to equal or better accuracy. This would provide the first accurate measurement of the H/A mass via invariant mass distribution techniques.