Discovering baryon-number violating neutralino decays at the LHC

TL;DR

It is demonstrated for the first time that a neutralino decaying to three quarks in models with baryonic violation of R parity might be observed directly at the LHC with high significance, by exploiting characteristics of the scales at which its composite jet breaks up into subjets.

Abstract

Recently there has been much interest in the use of single-jet mass and jet substructure to identify boosted particles decaying hadronically at the LHC. We develop these ideas to address the challenging case of a neutralino decaying to three quarks in models with baryonic violation of R-parity. These decays have previously been found to be swamped by QCD backgrounds. We demonstrate for the first time that such a decay might be observed directly at the LHC with high significance, by exploiting characteristics of the scales at which its composite jet breaks up into subjets.

Figures (3)

• Figure 1: The $y$-values from the $k_T$ algorithm with $R=0.4$ for the last and next-to-last merging for QCD jets (left), and jets matched to neutralinos (right). Also shown is the proposed cut line. Both distributions are normalized to unity.
• Figure 2: Jet mass distribution (points with error bars) for the $k_T$ algorithm (left) and C/A algorithm (right) after all cuts. Also shown are the contributions from QCD (black), supersymmetric events (red) and other SM backgrounds (green).
• Figure 3: Estimated sensitivity for 1 fb$^{-1}$ as a function of $\tilde{\chi}_1^0$ mass for various choices of jet algorithm and size $R$ (left), jet mass distribution for a squark search using the C/A algorithm with $R=0.5$ and background estimation by sidebands (right).