Probing new physics at the LHC with $\mathrm{b}\tau\nu$ final states

TL;DR

This paper explores new physics models like W' bosons and leptoquarks to explain the R_D(*) anomaly, and assesses their detectability at the LHC through specific final state signatures under various conditions.

Contribution

It provides feasibility studies for probing new physics explanations of the R_D(*) anomaly at the LHC with optimized selection criteria for different models.

Findings

Models can explain the R_D(*) anomaly and produce distinctive LHC signatures.

Feasibility of detecting these models varies with luminosity and energy.

Optimized selection improves signal significance for each scenario.

Abstract

The $R_{D^{(\ast)}}$ anomaly is one of the most intriguing experimental results in particle physics today. Experiments such as BaBar, Belle and LHCb have measured a consistent tension with the standard model (SM). We study several extensions of the SM that could potentially explain this tension, such as production of heavy $\mathrm{W}^{\prime}$ bosons, under the sequential SM scenario, leptoquarks with preferential couplings to third generation fermions, and interpretations through effective field theories. Such models, are not only able to explain the $R_{D^{(\ast)}}$ anomaly but also to produce distinctive signatures at the LHC. We present different feasibility studies to probe each of these scenarios at the LHC, considering final states with one $\mathrm{b}$-quark candidate, one hadronically decaying tau lepton ($\tau_{h}$) and missing transverse momentum ($p^{miss}_{\mathrm{T}}$). The selection criteria has been optimized for each model to achieve best signal signficance. The studies are performed considering different LHC running conditions, at $\sqrt{s} = 13 \, \mathrm{TeV}$ and 13.6 $\mathrm{TeV}$, and different luminosities (150~$\mathrm{fb}^{-1}$ and 3000~$\mathrm{fb}^{-1}$).