$R_{D^{(*)}}$ and survival of the fittest scalar leptoquark

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Bečirević, Damir, Fajfer, Svjetlana, Košnik, Nejc, Pavičić, Lovre
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909332004667392
author Bečirević, Damir
Fajfer, Svjetlana
Košnik, Nejc
Pavičić, Lovre
author_facet Bečirević, Damir
Fajfer, Svjetlana
Košnik, Nejc
Pavičić, Lovre
contents Motivated by the long-standing discrepancy in lepton flavor universality ratios $R_D$ and $R_{D^{\ast}}$ we assess the status of scalar leptoquark states $R_2$, $\widetilde R_2$ and $S_1$ which can in principle provide a desired enhancement of $\mathcal{B}(B\to D^{(\ast )}τν)$ in a minimal setup with two Yukawa couplings only. We consider unavoidable low-energy constraints, $Z$-pole measurements as well as high-$p_T$ constraints. After setting mass of each leptoquark to $1.5$ TeV we find that of all considered states only $S_1$ leptoquark, coupled to both chiralities of leptons and quarks, is still a completely viable solution while the scenario with $R_2$ is in growing tension with $Γ(Z \to ττ)$ and with the LHC constraints on the di-tau tails at high-$p_T$. We comment on the future experimental tests of $S_1$ scenario.
format Preprint
id arxiv_https___arxiv_org_abs_2404_16772
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle $R_{D^{(*)}}$ and survival of the fittest scalar leptoquark
Bečirević, Damir
Fajfer, Svjetlana
Košnik, Nejc
Pavičić, Lovre
High Energy Physics - Phenomenology
Motivated by the long-standing discrepancy in lepton flavor universality ratios $R_D$ and $R_{D^{\ast}}$ we assess the status of scalar leptoquark states $R_2$, $\widetilde R_2$ and $S_1$ which can in principle provide a desired enhancement of $\mathcal{B}(B\to D^{(\ast )}τν)$ in a minimal setup with two Yukawa couplings only. We consider unavoidable low-energy constraints, $Z$-pole measurements as well as high-$p_T$ constraints. After setting mass of each leptoquark to $1.5$ TeV we find that of all considered states only $S_1$ leptoquark, coupled to both chiralities of leptons and quarks, is still a completely viable solution while the scenario with $R_2$ is in growing tension with $Γ(Z \to ττ)$ and with the LHC constraints on the di-tau tails at high-$p_T$. We comment on the future experimental tests of $S_1$ scenario.
title $R_{D^{(*)}}$ and survival of the fittest scalar leptoquark
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2404.16772