On the breaking of lepton flavor universality in B decays
By Admir Greljo, G. Isidori, D. Marzocca. 2015
320 citations recorded by the source corpus.
A bstractIn view of recent experimental indications of violations of Lepton Flavor Universality (LFU) in B decays, we analyze constraints and implications of LFU interactions, both using an effective theory approach, and an explicit dynamical model. We show that a simple dynamical model based on a SU(2)L triplet of massive vector bosons, coupled predominantly to third generation fermions (both quarks and leptons), can significantly improve the description of present data. In particular, the model decreases the tension between data and SM predictions concerning: i) the breaking of τ-μ universality in B→D(*)ℓν decays; ii) the breaking of μ-e universality in B → Kℓ+ℓ− decays. Indirectly, the model might also decrease the discrepancy between exclusive and inclusive determinations of |Vcb| and |Vub|. The minimal version of the model is in tension with ATLAS and CMS direct searches for the new massive vectors (decaying into τ+τ− pairs), but this tension can be decreased with additional non-standard degrees of freedom. Further pre-dictions of the model both at low- and high-energies, in view of future high-statistics data, are discussed.
Subfields: Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/cfda5f0e3f643916f089ee481451718acccf1c12
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In Nuclear and High Energy Physics
- Gudrun Heinrich
- Atlas Collaboration
- Cms Collaboration
- Ansgar Denner
- Stefan Kallweit
- Stefan Dittmaier
- M. Grazzini
- Juan Rojo
Citations in the corpus
- Combined explanations of the b→sμ+μ− and b→cτ−ν¯ anomalies: A general model analysis (2018, methodology): “es that yield important constraints on the VBmodel: B0 s-B0 s mixing, neutrino trident production, ˝ !3and ˝ !. The rst three have been discussed in detail in Refs. [39,67], the fourth in Refs. [28,49]. Below we summarize the constraints. 4.1.1 B0 s-B0 s mixing The SM contribution to B0 s-B0 s mixin”
- Review of lepton universality tests in B decays (2018, background): “Various models with single mediators have been proposed, with heavy charged vector bosons (W ′) [179–182], heavy charged scalars (H ′) [183–190], or coloured vector or scalar bosons (leptoquarks) [145,176,177,191–204].”
- Charged Lepton Flavour Violation: An Experimental and Theoretical Introduction (2017, background): “As an illustration of the above discussion, let us consider – as in [220, 221, 222, 223, 224, 226, 227] – a scenario where the underlying new physics mainly generates operators involving third generations, i.”
- Phenomenology of an SU(2) × SU(2) × U(1) model with lepton-flavour non-universality (2016, background): “[81] while analysing a similar new physics case.”