An economical model for $B$-flavour and $a_\mu$ anomalies from SO(10) grand unification

TL;DR

This paper proposes a grand unification model based on SO(10) that explains B-flavour and muon g-2 anomalies, incorporates axion dark matter, and predicts new TeV-scale particles with specific phenomenological signatures.

Contribution

It introduces a minimal SO(10) GUT model with TeV-scale scalars and leptoquarks that simultaneously addresses flavor anomalies, muon g-2, and dark matter.

Findings

Achieves gauge coupling unification with one intermediate scale.

Provides a mechanism for proton stability via a discrete symmetry.

Offers a unified explanation for B-flavour and muon g-2 anomalies.

Abstract

We investigate an $\mathrm{SO}(10)$ grand unification scenario where the complex 10-dimensional scalar multiplet, containing the Standard Model (SM) Higgs boson, resides at the TeV scale altogether. The resulting low-energy model is a 2-Higgs-doublet model augmented with two $S_1$-type leptoquarks. The gauge-coupling unification is achieved with only one intermediate scale at which the Pati-Salam gauge group is broken down to the SM. Proton stability is ensured by a discrete symmetry, leftover from the breaking of the U(1)$_{\mathrm{PQ}}$ global symmetry. The axion corresponding to this broken U(1)$_{\mathrm{PQ}}$ provides a solution to the strong CP problem, and also serves as an important dark matter candidate. We discuss how the simultaneous explanation for the $R_{D^{(*)}}$ and $a_\mu$ anomalies comes about in the model, and investigate some of its phenomenological implications.