Two jets and missing $E_T$ signature to determine the spins of the new particles

TL;DR

This paper proposes a method to determine the spins of new colored particles at the LHC by analyzing jet and missing energy signatures, utilizing a three-site moose model to identify spin correlations in decay products.

Contribution

It introduces a novel approach using a three-site moose model and MAOS reconstruction to identify spin effects in jet plus missing energy events, distinguishing between models like LHT, UED, and SUSY.

Findings

Spin correlations affect angular distributions of decay quarks.

Observable effects appear in $E_T^{miss}/M_{eff}$ and azimuthal angle distributions.

Method can differentiate between models with different spin structures.

Abstract

We consider the spin determination of new colored particles in the missing energy plus jets channel at the early stage of LHC. We use a three site moose model to describe the low energy Lagrangian of all same spin partner (LHT or UED like) models and check the gauge invariance of the amplitude. For the benchmark production and decay channel $pp \rightarrow U^{(R)} U^{(R)} \rightarrow u u B_H B_H$, in contrast to those in supersymmetric models, there are spin correlations which affect the polar and azimuthal angle distributions of the quarks from the heavy partner $U^{(R)}$ decay. We show such effects would be visible in the $E_{\rm T miss} / M_{\rm eff}$ distribution and the reconstructed azimuthal angle correlation using MAOS reconstruction.