Probing heavy scalars with an effective $Hb\bar bg$ coupling at the LHC

TL;DR

This paper investigates the potential to detect a neutral scalar produced with a b-quark at the 14 TeV LHC, using an effective theory approach to explore the $Hb\bar bg$ coupling and employing machine learning for analysis.

Contribution

It introduces an effective $Hb\bar bg$ coupling framework to probe heavy scalars at the LHC, utilizing multivariate machine learning analysis for sensitivity estimation.

Findings

Potential to observe $3\sigma$ evidence for $m_H\lesssim 2$ TeV at 14 TeV LHC with 3000 fb$^{-1}$

Effective coupling sensitivity depends on scalar mass and new physics scale

Analysis demonstrates the viability of probing high-scale physics via effective operators

Abstract

We have explored the prospect of probing a neutral scalar ($H$) produced in association with one $b$-quark and decaying either invisibly or into a pair of $b$-quarks at the LHC with centre of mass energy $\sqrt s = 14$ TeV. In this regard, we adopt an effective theory approach to parameterize a $Hb\bar bg$ vertex arising from a dimension six operator that encompasses the effect of some new physics setting in at a high scale. We concentrate solely on the five-flavor scheme to ascertain the sensitivity of the 14 TeV LHC in probing such an effective coupling as a function of the scalar mass at the highest possible projected luminosity, $3000~{\rm fb}^{-1}$. Through our multivariate analysis using machine learning algorithm we show that staying within the perturbative limit of the Wilson coefficient of the effective interaction, evidence with statistical significance of $3\sigma$ can be obtained in two different signal regions for $m_H\lesssim 2$ TeV and the scale of new physics $\Lambda = 3$ TeV.