Flavor phenomenology of the leptoquark singlet-triplet model

Crivellin, Andreas; Müller, Dario; Saturnino, Francesco (2020). Flavor phenomenology of the leptoquark singlet-triplet model. Journal of High Energy Physics, 2020(6), 020. Springer 10.1007/JHEP06(2020)020

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In recent years, experiments revealed intriguing hints for new physics (NP) in semi-leptonic B decays. Both in charged current processes, involving b → cτν tran- sitions, and in the neutral currents b → sl+l−, a preference for NP compared to the standard model (SM) of more that 3σ and 5σ was found, respectively. In addition, there is the long-standing tension between the theory prediction and the measurement of the anomalous magnetic moment (AMM) of the muon (aμ) of more than 3σ. Since all these observables are related to the violation of lepton flavor universality (LFU), a common NP explanation seems not only plausible but is even desirable. In this context, leptoquarks (LQs) are especially promising since they give tree-level effects in semi-leptonic B decays, but only loop-suppressed effects in other flavor observables that agree well with their SM predictions. Furthermore, LQs can lead to a mt/mμ enhanced effect in aμ, allowing for an explanation even with (multi) TeV particles. However, a single scalar LQ representation cannot provide a common solution to all three anomalies. In this article we therefore con- sider a model in which we combine two scalar LQs: the SU(2)L singlet and the SU(2)L triplet. Within this model we compute all relevant 1-loop effects and perform a compre- hensive phenomenological analysis, pointing out various interesting correlations among the observables. Furthermore, we identify benchmark points which are in fact able to explain all three anomalies (b → cτν, b → sl+l− and aμ), without violating bounds from other observables, and study their predictions for future measurements.

Item Type:

Journal Article (Original Article)


10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC)
08 Faculty of Science > Institute of Theoretical Physics

UniBE Contributor:

Saturnino, Francesco


500 Science > 530 Physics








Esther Fiechter

Date Deposited:

02 Jul 2020 10:46

Last Modified:

02 Jul 2020 10:46

Publisher DOI:


ArXiv ID:






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