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Related papers: New physics facing LFU and LFV tests in B physics

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One of the exciting results in flavor physics in recent times is the $R_D$/$R_{D^*}$ puzzle. The measurements of these flavor ratios performed by the B-factory experiments, BaBar and Belle, and the LHCb experiment are about $4\sigma$ away…

High Energy Physics - Phenomenology · Physics 2018-07-31 Ashutosh Kumar Alok , Dinesh Kumar , Suman Kumbhakar , S Uma Sankar

The electroweak sector of the Standard Model contains three generations of charged leptons $\ell^-\in\{e^-,\mu^-,\tau^-\}$ as exact replicas of each other, except for their Yukawa couplings to the Higgs that determine their masses. The…

High Energy Physics - Experiment · Physics 2018-12-04 Biplab Dey

The current world averages of the ratios $R_{D^{(*)}}$ are about $4\sigma$ away from their Standard Model prediction. These measurements indicate towards the violation of lepton flavor universality in $b\rightarrow c\,l\,\bar{\nu}$ decay.…

High Energy Physics - Phenomenology · Physics 2020-02-18 Suman Kumbhakar , Ashutosh Kumar Alok , Dinesh Kumar , S Uma Sankar

We discuss the implications of $b \to s \ell^+\ell^-$ measurements and their deviations with respect to the Standard Model predictions in a model-independent framework. We highlight in particular the impact of the recent updated…

High Energy Physics - Phenomenology · Physics 2022-10-14 T. Hurth , F. Mahmoudi , D. Martinez Santos , S. Neshatpour

Nuclear $\beta$ decays as well as the decay of the neutron are well-established low-energy probes of physics beyond the Standard Model (SM). In particular, with the axial-vector coupling of the nucleon $g_A$ determined from lattice QCD, the…

High Energy Physics - Phenomenology · Physics 2020-09-11 Andreas Crivellin , Martin Hoferichter

We investigate Lepton Flavor Violation (LFV) in the general extension of the Standard Model parametrized by the gauge invariant operators of dimension-6. We discuss 3-body charged lepton decays and decay of $Z$ boson to lepton pair and…

High Energy Physics - Phenomenology · Physics 2014-05-20 Saereh Najjari

The coupling of the electroweak gauge bosons of the Standard Model (SM) to leptons is flavour universal. Extensions of the SM do not necessarily have this property. Rare decays of heavy flavour are suppressed in the SM and new particles may…

High Energy Physics - Experiment · Physics 2021-03-02 Carla Marin Benito

We explore the limits on lepton-flavor universality (LFU) violation in theories where the hierarchy problem is solved by means of a warped extra dimension. In those theories LFU violation, in fermion interaction with Kaluza-Klein modes of…

High Energy Physics - Phenomenology · Physics 2017-11-01 Eugenio Megias , Mariano Quiros , Lindber Salas

B-anomalies hint towards New Physics violating Lepton Flavor Universality at the TeV scale. The way they manifest points out to very particular structures for this New Physics. In this talk I review some UV-complete models to explain the…

High Energy Physics - Phenomenology · Physics 2022-03-11 Javier M. Lizana

In the Standard Model (SM), the rare transitions where a bottom quark decays into a strange quark and a pair of light leptons exhibit a potential sensitivity to physics beyond the SM. In addition, the SM embeds Lepton Flavour Universality…

High Energy Physics - Phenomenology · Physics 2018-02-14 Bernat Capdevila , Andreas Crivellin , Sébastien Descotes-Genon , Joaquim Matias , Javier Virto

Flavour-changing neutral-current processes, such as $b\to s \ell^+\ell^-$, are forbidden at tree level in the Standard Model and hence might receive comparatively large corrections from new particles. This document highlights recent…

High Energy Physics - Experiment · Physics 2023-03-22 M. Santimaria

The $B\to K^*\mu\mu$ decay exhibits deviations with respect to Standard Model expectations and the measurement of the ratio $R_K$ hints at a violation of lepton-flavour universality in $B\to K\ell\ell$ transitions. Both effects can be…

High Energy Physics - Phenomenology · Physics 2017-09-13 Bernat Capdevila , Sebastien Descotes-Genon , Joaquim Matias , Javier Virto

The basic features of quark and lepton mass matrices can be successfully explained by natural minima of a generic potential with dynamical Yukawa fields invariant under the $[\mathrm{SU(3)}]^5\times \mathcal{O}(3)$ flavor symmetry. If this…

High Energy Physics - Phenomenology · Physics 2017-01-18 Andreas Crivellin , Javier Fuentes-Martin , Admir Greljo , Gino Isidori

The impact of rare K decays and lepton-flavor violating processes in shedding light on physics beyond the Standard Model is reviewd. To this purpose, I first recall the formulation of the Minimal Flavor Violation hypothesis --both in the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Gino Isidori

Lepton flavour violation (LFV), and lepton flavour university violation (LFUV), are striking signatures of beyond the Standard Model (BSM) physics. Recent searches for these at the ATLAS and CMS experiments are presented, using…

High Energy Physics - Experiment · Physics 2024-05-21 Holly Pacey

In this work we study the potential of the lepton flavor ratios $R_{K}^{\tau \mu} \equiv \Gamma(B \to K \tau^+ \tau^-)/ \Gamma(B \to K \mu^+ \mu^-)$ and $ R_{K^{*}}^{\tau \mu} \equiv \Gamma(B \to K^* \tau^+ \tau^-)/ \Gamma(B \to K^* \mu^+…

High Energy Physics - Phenomenology · Physics 2023-10-27 Ashutosh Kumar Alok , Neetu Raj Singh Chundawat , Arindam Mandal

Experimental hints for lepton flavor universality violation in beauty-quark decay both in neutral- and charged-current transitions require an extension of the Standard Model for which scalar leptoquarks (LQs) are the prime candidates.…

High Energy Physics - Phenomenology · Physics 2022-09-21 J. Julio , Shaikh Saad , Anil Thapa

We explore a scenario of New Physics entering the description of $B\to K^{(\ast )} \mu \mu$ decay through couplings to the operators ${\cal O}_{9,10}^\prime$, satisfying $C_9^\prime = - C_{10}^\prime$. From the current data on ${\cal…

High Energy Physics - Phenomenology · Physics 2016-08-10 Damir Bečirević , Svjetlana Fajfer , Nejc Košnik

We investigate the possibility of lepton flavor violation in the decays $\mu\to e\gamma$, $\tau \to \mu\gamma$ and $\tau \to e\gamma$ as well as electric dipole moment and anomalous magnetic moment of charged leptons in the extension of the…

High Energy Physics - Phenomenology · Physics 2013-12-17 Saereh Najjari

Recently reported anomalies in various $B$ meson decays and also in the anomalous magnetic moment of muon $(g-2)_\mu$ motivate us to consider a particular extension of the standard model incorporating new interactions in lepton and quark…

High Energy Physics - Phenomenology · Physics 2023-01-18 Kayoung Ban , Yongsoo Jho , Youngjoon Kwon , Seong Chan Park , Seokhee Park , Po-Yan Tseng