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Related papers: Some results on Lepton Flavour Universality Violat…

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We discuss the implications of the recently reported $R_K$ and $R_{K^*}$ anomalies, the lepton flavor non-universality in the $B\to K\ell^+\ell^-$ and $B\to K^*\ell^+\ell^-$. Using two sets of hadronic inputs of form factors, we perform a…

High Energy Physics - Phenomenology · Physics 2017-12-08 Wei Wang , Shuai Zhao

Using the general, model independent form of the effective Hamiltonian, the general expressions of the longitudinal, normal and transversal polarization asymmetries for (l^-) and (l^+) and combinations of them for the exclusive (B -> K l^+…

High Energy Physics - Phenomenology · Physics 2009-11-07 T. M. Aliev , M. K. Cakmak , A. Ozpineci , M. Savci

We discuss the impact of the recent LHCb update on the two lepton-flavour universality ratios $R_K$ and $R_{K^*}$, and the CMS update of $B({B_s \to \mu^+\mu^-})$ regarding the possibility of New Physics in $b\to s\ell^+\ell^-$ decays. We…

High Energy Physics - Phenomenology · Physics 2024-05-30 Marcel Algueró , Aritra Biswas , Bernat Capdevila , Sébastien Descotes-Genon , Joaquim Matias , Martín Novoa-Brunet

A recent proposal for explaining discrepancies in angular observables in the rare decay B --> K*mu+mu- with a gauged L_mu - L_tau current carried with it the prediction of lepton flavor universality violation in related B-meson decays. This…

High Energy Physics - Phenomenology · Physics 2015-10-21 Wolfgang Altmannshofer , Itay Yavin

In the Standard Model of particle physics, charged leptons of different flavour couple to the electroweak force carriers with the same interaction strength. This property, known as lepton flavour universality, was found to be consistent…

High Energy Physics - Experiment · Physics 2021-05-24 Davide Lancierini

Leptoquarks are prime candidates for explaining the intriguing hints for lepton flavour universality violation. In particular, the $SU(2)_L$ doublet of scalar leptoquarks $S_2$ is capable of providing an explanation for the tensions between…

High Energy Physics - Phenomenology · Physics 2022-07-05 Andreas Crivellin , Benjamin Fuks , Luc Schnell

Experimental data on rare $B$-meson decays indicate deviations from Standard Model predictions. In studies of these decays, possible new sources of CP violation are often neglected. We discuss CP violation in the rare $B$-meson decays $B\to…

High Energy Physics - Phenomenology · Physics 2024-04-12 Robert Fleischer , Eleftheria Malami , Anders Rehult , K. Keri Vos

We study the Standard Model and the new physics predictions for the lepton-flavour-universality violating (LFUV) ratios in various $b\to s \ell^+\ell^-$ channels with scalar, pseudoscalar, vector, axial-vector, and $\Lambda$ baryon final…

High Energy Physics - Phenomenology · Physics 2022-03-31 Faisal Munir Bhutta , Zhuo-Ran Huang , Cai-Dian Lü , M. Ali Paracha , Wenyu Wang

Rare semileptonic $b \to s \ell^+ \ell^-$ transitions provide some of the most promising frameworks to search for new physics effects. Recent analyses of these decays have indicated an anomalous behaviour in measurements of angular…

High Energy Physics - Phenomenology · Physics 2019-03-21 Andrea Mauri , Nicola Serra , Rafael Silva Coutinho

LHCb found hints for physics beyond the Standard Model (SM) in $B\to K^*\mu^+\mu^-$, $R(K)$ and $B_s\to\phi\mu^+\mu^-$. These intriguing hints for NP have recently been confirmed by the LHCb measurement of $R(K^*)$ giving a combined…

High Energy Physics - Phenomenology · Physics 2017-06-06 Andreas Crivellin

The evidence for Lepton Flavour Universality (LFU) violation in semileptonic $B$-decays has been rising over the past few years. Relying on generic effective field theory (EFT) results, it has been shown that models addressing the…

High Energy Physics - Phenomenology · Physics 2022-07-25 Lukas Allwicher , Nudžeim Selimović

LHCb has reported deviations from the Standard Model in $b\to s\mu^+\mu^-$ transitions for which a new neutral gauge boson is a prime candidate for an explanation. As this gauge boson has to couple in a flavour non-universal way to muons…

High Energy Physics - Phenomenology · Physics 2015-09-25 Andreas Crivellin , Lars Hofer , Joaquim Matias , Ulrich Nierste , Stefan Pokorski , Janusz Rosiek

We construct an expression for a general lepton flavour universality (LFU) ratio, $R_{X}$, in $b\to s l^+ l^-$ decays in terms of a series of hadronic quantities which can be treated as nuisance parameters. This expression allows to include…

High Energy Physics - Phenomenology · Physics 2022-06-01 Gino Isidori , Davide Lancierini , Abhijit Mathad , Patrick Owen , Nicola Serra , Rafael Silva Coutinho

Precision measures of electroweak and flavour observables, at both low and high energies, are highly complementary to direct searches for New Physics at high-energy colliders. Despite the discovery of the Higgs boson at the Large Hadron…

High Energy Physics - Phenomenology · Physics 2022-03-01 Jonathan Kriewald

Within the standard approach of effective field theory of weak interactions for $\Delta B = 1$ transitions, we look for possibly unexpected subtle New Physics effects, here dubbed "flavourful Easter eggs". We perform a Bayesian global fit…

High Energy Physics - Phenomenology · Physics 2017-10-04 Marco Ciuchini , Antonio M. Coutinho , Marco Fedele , Enrico Franco , Ayan Paul , Luca Silvestrini , Mauro Valli

We briefly report on some particular aspects of new physics searches concerning, on the one side, the CKM paradigm and, on the other, the global fit to rare $b\to s \ell\ell$ observables including lepton flavour universality ones. We put…

High Energy Physics - Phenomenology · Physics 2017-11-13 Joaquim Matias

We explore the possibility that lepton family numbers and baryon number are such good symmetries of Nature because they are the global remnant of a spontaneously broken gauge symmetry. An almost arbitrary linear combination of these…

High Energy Physics - Phenomenology · Physics 2020-01-15 Wolfgang Altmannshofer , Joe Davighi , Marco Nardecchia

It is presented an analysis on lepton flavour violating transitions, leptonic magnetic dipole moments and electric dipole moments in a class of models characterized by the flavour symmetry A4 x Z3 x U(1)_FN, whose choice is motivated by the…

High Energy Physics - Phenomenology · Physics 2009-07-22 Luca Merlo

Following the updated measurement of the lepton flavour universality (LFU) ratio R_K in B -> Kll decays by LHCb, as well as a number of further measurements, e.g. R_K* by Belle and B_s -> mu mu by ATLAS, we analyse the global status of new…

High Energy Physics - Phenomenology · Physics 2020-04-22 Jason Aebischer , Wolfgang Altmannshofer , Diego Guadagnoli , Meril Reboud , Peter Stangl , David M. Straub

We calculate a number of observables related to particle-antiparticle mixing and the branching ratios for the most interesting rare and CP-violating K and B decays in the Standard Model (SM3) extended by a fourth generation of quarks and…

High Energy Physics - Phenomenology · Physics 2010-12-01 Andrzej J. Buras , Björn Duling , Thorsten Feldmann , Tillmann Heidsieck , Christoph Promberger , Stefan Recksiegel