Flavor anomalies from asymptotically safe gravity

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2021-04, Vol.81 (4), p.1-21, Article 272
• Main Authors: Kowalska, Kamila, Sessolo, Enrico Maria, Yamamoto, Yasuhiro
• Format: Article
• Language: English
• Subjects: Anomalies; Astronomy; Astrophysics and Cosmology; Asymptotic properties; Boundary conditions; Couplings; Elementary Particles; Energy value; Flavor (particle physics); Gravity; Hadrons; Heavy Ions; Kaons; Large Hadron Collider; Measurement Science and Instrumentation; Mesons; Nuclear Energy; Nuclear Physics; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum gravity; Regular Article – Theoretical Physics; String Theory
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-021-09072-1

We use the framework of asymptotically safe quantum gravity to derive predictions for scalar leptoquark solutions to the b → s and b → c flavor anomalies. The presence of an interactive UV fixed point in the system of gauge and Yukawa couplings imposes a set of boundary conditions at the Planck scale, which allows one to determine low-energy values of the leptoquark Yukawa matrix elements. As a consequence, the allowed leptoquark mass range can be significantly narrowed down. We find that a consistent gravity-driven solution to the b → s anomalies predicts a leptoquark with the mass of 4–7 TeV , entirely within the reach of a future hadron-hadron collider with s = 100 TeV . Conversely, in the case of the b → c anomalies the asymptotically safe gravity framework predicts a leptoquark mass at the edge of the current LHC bounds. Complementary signatures appear in flavor observables, namely the (semi)leptonic decays of B and D mesons and kaons.