Updated Bs -mixing constraints on new physics models for b→sℓ+ℓ− anomalies

Di Luzio, Luca; Kirk, Matthew; Lenz, Alexander

Abstract

Many new physics models that explain the intriguing anomalies in the b-quark flavor sector are severely constrained by Bs mixing, for which the Standard Model prediction and experiment agreed well until recently. The most recent Flavour Lattice Averaging Group (FLAG) average of lattice results for the nonperturbative matrix elements points, however, in the direction of a small discrepancy in this observable Cabibbo-Kobayashi-Maskawa (CKM). Using up-to-date inputs from standard sources such as PDG, FLAG and one of the two leading CKM fitting groups to determine ΔMSM s , we find a severe reduction of the allowed parameter space of Z0 and leptoquark models explaining the B anomalies. Remarkably, in the former case the upper bound on the Z0 mass approaches dangerously close to the energy scales already probed by the LHC. We finally identify some model-building directions in order to alleviate the tension with Bs mixing.

Citation

Di Luzio, L., Kirk, M., & Lenz, A. (2018). Updated Bs -mixing constraints on new physics models for b→sℓ+ℓ− anomalies. Physical Review D, 97(9), Article 095035. https://doi.org/10.1103/physrevd.97.095035

• Journal Article Type: Article
• Online Publication Date: May 25, 2018
• Publication Date: May 25, 2018
• Deposit Date: Jun 7, 2018
• Publicly Available Date: Jun 7, 2018
• Journal: Physical Review D
• Print ISSN: 2470-0010
• Electronic ISSN: 2470-0029
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 97
• Issue: 9
• Article Number: 095035
• DOI: https://doi.org/10.1103/physrevd.97.095035