RD() motivated S1 leptoquark scenarios: Impact of interference on the exclusion limits from LHC data

• Published in: Physical review. D 2019-03, Vol.99 (5)
• Main Authors: Mandal, Tanumoy, Mitra, Subhadip, Raz, Swapnil
• Format: Article
• Language: English
• Subjects: Anomalies; Interference; Large Hadron Collider; Mathematical models; Parameters; Statistical analysis
• ISSN: 2470-0010; 2470-0029
• DOI: 10.1103/PhysRevD.99.055028

Motivated by the persistent anomalies in the semileptonic B-meson decays, we investigate the competency of LHC data to constrain the RD(*)-favored parameter space in a charge −1/3 scalar leptoquark (S1) model. We consider some scenarios with one large free coupling to accommodate the RD(*) anomalies. As a result, some of them dominantly yield nonresonant ττ and τν events at the LHC through the t-channel S1 exchange. So far, no experiment has searched for leptoquarks using these signatures and the relevant resonant leptoquark searches are yet to put any strong exclusion limit on the parameter space. We recast the latest ττ and τν resonance search data to obtain new exclusion limits. The nonresonant processes strongly interfere (destructively in our case) with the Standard Model background and play the determining role in setting the exclusion limits. To obtain precise limits, we include non-negligible effects coming from the subdominant (resonant) pair and inclusive single leptoquark productions systematically in our analysis. To deal with large destructive interference, we make use of the transverse mass distributions from the experiments in our statistical analysis. In addition, we also recast the relevant direct search results to obtain the most stringent collider bounds on these scenarios to date. These are independent bounds and are competitive to other known bounds. Finally, we indicate how one can adopt these bounds to a wide class of models with S1 that are proposed to accommodate the RD(*) anomalies.