Probing heavy scalars with an effective $Hb\bar{b}g$ coupling at the LHC

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 $Hb\bar{b}g$ 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, $3000{\mathrm{fb}}^{-1}$. 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.

Comments: 9 pages, 4 figures, 2 tables