Addressing the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>R</mml:mi></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mo mathvariant="bold" stretchy="false">(</mml:mo><mml:mo>*</mml:mo><mml:mo mathvariant="bold" stretchy="false">)</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:msub></mml:mrow></mml:math> anomalies with an <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>S</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math> leptoquark from SO(10) grand unification

Abstract

Motivated by the ${R}_{{D}^{(*)}}$ anomalies, we investigate an SO(10) grand unification scenario where a charge $\ensuremath{-}1/3$ scalar leptoquark (${S}_{1}$) remains as the only new physics candidate at the TeV scale. This leptoquark along with the Standard Model (SM) Higgs doublet originates from the same ten-dimensional real scalar multiplet in the SO(10) grand unification framework taking its mass close to the electroweak scale. We explicitly show how the gauge coupling unification is achieved with only one intermediate symmetry-breaking scale at which the Pati-Salam gauge group is broken into the SM group. We investigate the phenomenological implications of our scenario and show that an ${S}_{1}$ with a specific Yukawa texture can explain the ${R}_{{D}^{(*)}}$ anomalies. We perform a multiparameter scan considering the relevant flavor constraints on ${R}_{{D}^{(*)}}$, ${F}_{L}({D}^{*})$, ${P}_{\ensuremath{\tau}}({D}^{*})$ and ${R}_{{K}^{(*)}}^{\ensuremath{\nu}\ensuremath{\nu}}$ as well as the constraint coming from the $Z\ensuremath{\rightarrow}\ensuremath{\tau}\ensuremath{\tau}$ decay and the latest $\ensuremath{\tau}\ensuremath{\tau}$ resonance search data at the LHC. Our analysis shows that a single leptoquark solution to the observed ${R}_{{D}^{(*)}}$ anomalies with ${S}_{1}$ is still a viable solution.

Topics & Concepts