Polynomials, Riemann surfaces, and reconstructing missing-energy events

TL;DR

This paper introduces a novel approach using Riemann surface theory to reconstruct missing energy events in collider physics, addressing combinatorial ambiguities and measurement errors for improved particle property determination.

Contribution

It formulates the reconstruction problem in collider events within the framework of Riemann surfaces, providing new methods to handle ambiguities and errors in complex decay processes.

Findings

Demonstrates the method on top quark decay events

Applies to dark matter candidate decays in new physics models

Improves accuracy in Higgs to tau tau decay analysis

Abstract

We consider the problem of reconstructing energies, momenta, and masses in collider events with missing energy, along with the complications introduced by combinatorial ambiguities and measurement errors. Typically, one reconstructs more than one value and we show how the wrong values may be correlated with the right ones. The problem has a natural formulation in terms of the theory of Riemann surfaces. We discuss examples including top quark decays in the Standard Model (relevant for top quark mass measurements and tests of spin correlation), cascade decays in models of new physics containing dark matter candidates, decays of third-generation leptoquarks in composite models of electroweak symmetry breaking, and Higgs boson decay into two tau leptons.