Early spin determination at the LHC?

TL;DR

This paper proposes a method to determine the spin of new particles at the LHC using angular distributions, effective with low luminosity, and applicable across different models.

Contribution

It introduces a spin determination technique based on jet-pair rapidity differences that does not depend on specific decay coupling structures.

Findings

Significant differences in rapidity distributions can distinguish spin structures.

Method effective with as low as 1 fb^-1 of data at 14 TeV.

Distinction possible between supersymmetric and UED-like models early on.

Abstract

If signals of new physics are discovered at the LHC it will be crucial to determine the spin structure of the new model. We discuss a method that can help to address this question with a low integrated luminosity, L=1 fb^-1, at sqrt{s}=14 TeV. Based on the differences in angular distributions of primarily produced particles we show that a significant difference can be observed in the final state jet-pairs rapidity distance. An additional advantage of the method is that it does not rely on any particular structure of the couplings in the decay chain. We simulate samples for models with supersymmetric and UED-like spin structure and show that a distinction can be made early on.