Measuring the Bottom-Quark Forward-Central Asymmetry at the LHC

TL;DR

This paper proposes a method to measure the bottom quark forward-central asymmetry at the LHC, aiming to detect new physics effects similar to those suggested by top quark asymmetry measurements, which could constrain theoretical models.

Contribution

It introduces a novel analysis strategy for the bottom quark asymmetry at the LHC, including specific cuts and testing on a toy axigluon model, to identify potential new physics signals.

Findings

Effects are detectable at 2 sigma with less than 10 fb-1 of data.

Measurement can constrain models explaining the top asymmetry.

Requires low trigger thresholds for muons inside jets.

Abstract

Measurements of the top quark forward-backward asymmetry performed at the Tevatron suggest that new-physics may be playing a role in t-tbar production. To better understand the source of the asymmetry, recent proposals have called for a measurement of the bottom and charm forward-backward asymmetries at the Tevatron, using jets with embedded muons. Here we propose a corresponding measurement of the bottom quark forward-central asymmetry designed to look for similar effects in the b-sector at ATLAS and CMS. We construct a set of cuts designed to enhance sensitivity to this asymmetry, and test our analysis on a toy axigluon model representative of those used to explain the top asymmetry. We find that if the relevant new-physics couplings to the bottom quark are similar to those of the top, then the effects should be visible at the two sigma level in less than 10 fb-1 of 7 TeV LHC data. Such a measurement would be of general importance, and would provide valuable model-building input, serving to restrict the set of models put forward to explain the Tevatron t-tbar anomaly. However, a relatively low trigger threshold on non-isolated muons inside hard jets must be maintained to allow for this measurement.