B-physics anomalies: a guide to combined explanations

By D. Buttazzo, Admir Greljo, G. Isidori, D. Marzocca. Journal of High Energy Physics, 2017

423 citations recorded by the source corpus.

Motivated by additional experimental hints of Lepton Flavour Universality violation in B decays, both in charged- and in neutral-current processes, we analyse the ingredients necessary to provide a combined description of these phenomena. By means of an Effective Field Theory (EFT) approach, based on the hypothesis of New Physics coupled predominantly to the third generation of left-handed quarks and leptons, we show how this is possible. We demonstrate, in particular, how to solve the problems posed by electroweak precision tests and direct searches with a rather natural choice of model parameters, within the context of a U(2)q ×U(2)ℓ flavour symmetry. We further exemplify the general EFT findings by means of simplified models with explicit mediators in the TeV range: coloured scalar or vector leptoquarks and colour-less vectors. Among these, the case of an SU(2)L-singlet vector leptoquark emerges as a particularly simple and successful framework.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/f42d5178abae397b85546512ae063b56a65039d2

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Nuclear and High Energy Physics

Citations in the corpus

Review of lepton universality tests in B decays (2018, methodology): “of Yukawa couplings in the SM, it is possible to provide a hierarchical structure for the avour coupling matrices q and ‘ without con icting with other low-energy constraints or high-pT constraints [170]. 8.2 Specic models The EFT approach provides constraints on Wilson coecients encoding the short-”
Charged Lepton Flavour Violation: An Experimental and Theoretical Introduction (2017, background): “((22)) For a recent discussion about models that address both classes of anomalies see [225].”
Physics beyond colliders at CERN: beyond the Standard Model working group report (2019, background): “Measurements of the K → πνν BRs are critical to interpreting the data from rare B decays, and may demonstrate that these effects are a manifestation of new degrees of freedom such as leptoquarks [115–117].”
Combined explanations of the b→sμ+μ− and b→cτ−ν¯ anomalies: A general model analysis (2018, background): “the NP couples only to the third generation in the weak basis, with the couplings to the second generation induced when one transforms to the mass basis. This is the assumption made in Refs. [39] and [49]; the papers dier in the form of the transformations from the weak to the mass basis. We note in”
Beyond the Standard Model Physics at the HL-LHC and HE-LHC (2018, methodology): “[434] for details on the present LHC constraints).”
Revisiting the vector leptoquark explanation of the B-physics anomalies (2019, background): “ emerged as an excellent mediator for the explanation of both sets of anomalies. The eectiveness of this state as single-mediator accounting for all available low-energy data has been established in [43]. However, the analysis of Ref. [43], as most other phenomenological analyses of the U 1 leptoqua”
Baryon number and lepton universality violation in leptoquark and diquark models (2017, result): “covered anomalies in B meson decays, in agreement with all other experimental data [11, 24].”
B-decay discrepancies after Moriond 2019 (2019, background): “ion is the preferred region from R D( ), while the gray shaded area is excluded by leptonic tau decays at the 2˙level. The hatched areas are excluded by LHC searches recasted in [109]. pointed out in [86,104], there is already some tension between this natural expectation and the direct searches. We”