Probing heavy scalars with an effective $Hbbar bg$ coupling at the LHC


Abstract in English

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 $Hbbar bg$ 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 $3sigma$ can be obtained in two different signal regions for $m_Hlesssim 2$ TeV and the scale of new physics $Lambda = 3$ TeV.

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