Discovery in Drell-Yan Processes at the LHC

TL;DR

This paper investigates the properties of hypothetical new bosonic resonances in Drell-Yan processes at the LHC, providing model-independent methods to determine their spin, mass, and couplings using kinematic distributions and asymmetries.

Contribution

It introduces a comprehensive, model-independent framework for analyzing new bosonic resonances, including novel techniques for reconstructing angular distributions and determining resonance properties.

Findings

Current LHC data constrains resonance mass and cross section.

Methods to distinguish spin and chiral couplings are demonstrated.

Future LHC runs could significantly improve sensitivity.

Abstract

We study the Drell-Yan process mediated by a new bosonic resonance at the LHC. The bosons of spin-0, 1, and 2 with the most general leading-order couplings to Standard Model fermions and gluons are considered, which provide a model-independent formulation for future exploration of the resonance properties, such as its spin, mass and couplings. In the case of neutral resonances, we demonstrate how the shapes of the kinematical distributions change as one varies the chiral couplings of the quarks and leptons, and show how to analyze the couplings by making use of the forward-backward asymmetry. In the case of charged resonances, we propose a novel technique to effectively reconstruct the angular distribution in the center-of-mass frame, to a large extent avoiding the two-fold ambiguity due to the missing neutrino. Similar to the case of a neutral resonance, the spin information of the resonance can be extracted unambiguously, and chiral couplings and the asymmetries can be explored in a statistical manner. With the current LHC data, we present bounds on the mass and cross section times branching fraction of the new resonance and estimate the future reach.