$B$-anomalies in a twin Pati-Salam theory of flavour including the 2022 LHCb $R_{K^{(\ast )}}$ analysis

Abstract

We perform a comprehensive phenomenological analysis of the twin Pati-Salam theory of flavour, focussing on the parameter space relevant for interpreting the $B$-anomalies via vector leptoquark $U_1$ exchange. This model provides a very predictive framework in which the $U_1$ couplings and the Yukawa couplings find a common origin via mixing of chiral quarks and leptons with vector-like fermions, providing a direct link between the $B$-anomalies and the fermion masses and mixing. We propose and study a simplified model with three vector-like fermion families, in the massless first family approximation, and show that the second and third family charged fermion masses and mixings and the $B$-anomalies can be simultaneously explained and related. The model has the proper flavour structure to be compatible with all low-energy observables, and leads to predictions in promising observables such as $\tau \to 3\mu$, $\tau \to \mu \gamma$ and $B\to K^{(\ast )}\nu \bar{\nu }$ at Belle II and LHCb. The model also predicts a rich spectrum of TeV scale gauge bosons and vector-like fermions, all accessible to the LHC. In this updated version we have included an extended analysis considering the new 2022 LHCb data on $R_{K^{(\ast )}}$, which has slightly shifted the preferred parameter space with respect to the 2021 case. The model can still explain the $R_{D^{(\ast )}}$ anomalies at 1$\sigma$ in a narrow window, however we expect small deviations from the SM on the $R_{K^{(\ast )}}$ ratios, to be tested in the future via more precise measurements by the LHCb collaboration. We also predict $\Delta R_D=\Delta R_{D^{\ast }}$, with future measurements shifting the world averages to slightly smaller central values.

44 pages + appendices and references, 14 figures. v5: Typos corrected

References in corpus (25)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• FLAG Review 2021
• Addressing the LHC flavour anomalies with horizontal gauge symmetries
• Gauge leptoquark as the origin of B-physics anomalies
• The Leptoquark Hunter's Guide: Pair Production
• On the single leptoquark solutions to the $B$-physics anomalies
• $\Delta M_s$ theory precision confronts flavour anomalies
• Reading the footprints of the B-meson flavor anomalies
• Improved Theory Predictions and Global Analysis of Exclusive $\mathbf{b}\to \mathbf{s}{\mathbf{\mu }}^{+}{\mathbf{\mu }}^{-}$ Processes
• Bs mixing observables and Vtd/Vts from sum rules
• High-pT Signatures in Vector-Leptoquark Models
• Implications of new evidence for lepton-universality violation in $b\to s{\ell }^{+}{\ell }^{-}$ decays
• $b\to s\ell \ell$ Global Fits after $R_{K_S}$ and $R_{K^{\ast +}}$
• DsixTools 2.0: The Effective Field Theory Toolkit
• Third-family quark-lepton unification with a fundamental composite Higgs
• Flavourful $Z^{\prime }$ models for $R_{K^{(\ast )}}$
• Flavor hierarchies, flavor anomalies, and Higgs mass from a warped extra dimension
• Vector Leptoquarks Beyond Tree Level
• On new physics in $\Delta {\Gamma }_d$
• Vector Leptoquarks Beyond Tree Level III: Vector-like Fermions and Flavor-Changing Transitions
• Is it possible to explain the muon and electron $g-2$ in a $Z^{\prime }$ model?
• The Flavor of UV Physics
• Disentangling Lepton Flavour Universal and Lepton Flavour Universality Violating Effects in $b\to s{\ell }^{+}{\ell }^{-}$ Transitions
• Twin Pati-Salam theory of flavour with a TeV scale vector leptoquark
• Simplified models of vector $SU(4)$ leptoquarks at the TeV

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• Anomalies in Particle Physics
• Non-universal gauge interactions addressing the inescapable link between Higgs and Flavour
• Tri-hypercharge: a separate gauged weak hypercharge for each fermion family as the origin of flavour
• Electroweak-flavour and quark-lepton unification: a family non-universal path
• Global fit to $b\to c\tau \nu$ anomalies as of Spring 2024
• Review of Semileptonic $B$ Anomalies
• Minimal complete tri-hypercharge theories of flavour
• Flavour Deconstructing the Composite Higgs
• Diquark Explanation of $b\to s{\ell }^{+}{\ell }^{-}$
• Test of lepton flavour universality with $B_s^0\to \varphi {\ell }^{+}{\ell }^{-}$ decays
• All possible first signals of gauge leptoquark in quark-lepton unification and beyond
• ${\tau }_{B_s}/{\tau }_{B_d}$ and $\Delta {\Gamma }_s$ confront new physics in $b\to s\tau \tau$
• Vector leptoquark contributions to lepton dipole moments
• Gravitational wave signals from leptoquark-induced first order electroweak phase transitions