English
Related papers

Related papers: A New Light Particle in B Decays?

200 papers

Tests of lepton-universality as rate ratios in $b\to s \ell\ell$ transitions can be predicted very accurately in the Standard Model. The deficits with respect to expectations reported by the LHCb experiment in muon-to-electron ratios of the…

High Energy Physics - Phenomenology · Physics 2020-02-03 Li-Sheng Geng , Benjamín Grinstein , Sebastian Jäger , Jorge Martin Camalich , Xiu-Lei Ren , Rui-Xiang Shi

We investigate a gauge extension of the Standard Model in light of the observed hints of lepton universality violation in $b \to c \ell \nu$ and $b \to s \ell^+ \ell^-$ decays at BaBar, Belle and LHCb. The model consists of an extended…

High Energy Physics - Phenomenology · Physics 2016-12-19 Sofiane M. Boucenna , Alejandro Celis , Javier Fuentes-Martin , Avelino Vicente , Javier Virto

Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios $R_K$ and $R_{K^*}$. The currently observed values align with the predictions of the standard model. In light of these recent updates, our…

High Energy Physics - Phenomenology · Physics 2024-10-04 Juhi Vardani , Ria Sain

The experimental measurements on flavour physics, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. This note summarises an analysis of the effects of the global fits to the Wilson…

High Energy Physics - Phenomenology · Physics 2021-06-15 Jorge Alda , Jaume Guasch , Siannah Penaranda

The LHCb experiment has made several measurements in $b \to s$ transitions which indicate tensions with the Standard Model predictions. Assuming the source of these tensions to be new physics, we present new global fits to all Wilson…

High Energy Physics - Phenomenology · Physics 2018-12-20 T. Hurth , A. Arbey , F. Mahmoudi , S. Neshatpour

Flavor symmetries successfully explain lepton and quark masses and mixings yet it is usually hard to distinguish different models that predict the same mixing angles. Further experimental input could be available, if the agents of flavor…

High Energy Physics - Phenomenology · Physics 2015-09-03 Ivo de Medeiros Varzielas , Gudrun Hiller

The LHCb Collaboration's measurement of R_K = B(B+ -> K+ mu+ mu-)/B(B+ -> K+ e+e-) lies 2.6 sigma below the Standard Model prediction. Several groups suggest this deficit to result from new lepton non-universal interactions of muons. But…

High Energy Physics - Phenomenology · Physics 2015-03-11 Sheldon L. Glashow , Diego Guadagnoli , Kenneth Lane

Lepton Flavor Universality Violation (LFUV) in $B$ decays in both neutral $b\rightarrow s l^+ l^-$ and charged $b\rightarrow cl\bar{\nu}_{l}$ processes observed in the ratios $R_{K^{(*)}}$ and $R_{D^{(*)}}$ is investigated in the framework…

High Energy Physics - Phenomenology · Physics 2022-02-16 Soumia Lebbal , Jamal Mimouni , Noureddine Mebarki

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

Flavour physics plays a crucial role in the search for physics beyond the Standard Model (SM). While $B$ physics offers many observables to look for deviations from the SM, the highest new physics sensitivity can be obtained in the rare…

High Energy Physics - Phenomenology · Physics 2014-12-03 Monika Blanke

We discuss the possibility of using the observables deduced from the angular distribution of the $B\to D^{(\ast)} \ell\bar{\nu}$ decays to test the effects of lepton flavor universality violation (LFUV). We show that the measurement of even…

High Energy Physics - Phenomenology · Physics 2019-07-16 Damir Becirevic , Marco Fedele , Ivan Nisandzic , Andrey Tayduganov

In the light of the recent result of the Muon g-2 experiment and the update on the test of lepton flavour universality $R_K$ published by the LHCb collaboration, we systematically build and discuss a set of models with minimal field content…

High Energy Physics - Phenomenology · Physics 2021-08-11 Giorgio Arcadi , Lorenzo Calibbi , Marco Fedele , Federico Mescia

In this paper, we study the light scalar and pseudoscalar invisible particles in the flavor changing neutral current processes of the $B_c$ meson. Effective operators are introduced to describe the couplings between quarks and light…

High Energy Physics - Phenomenology · Physics 2019-03-12 Geng Li , Tianhong Wang , Yue Jiang , Xiao-Ze Tan , Guo-Li Wang

Recent results from the LHCb experiment have confirmed that lepton flavor universality is upheld in flavor-changing neutral current processes, such as $B \to K^{(*)} l^+ l^-$. However, discrepancies remain in the charged current sector,…

High Energy Physics - Phenomenology · Physics 2025-10-08 Ajay Kumar Yadav , Suchismita Sahoo

Recent results from the LHC's first run have revealed intriguing departures from lepton flavour universality in the semi-leptonic decays of $B$-mesons. We discuss the complementary role that rare kaon decays can provide in testing new…

High Energy Physics - Phenomenology · Physics 2017-04-05 Lewis C. Tunstall , Andreas Crivellin , Giancarlo D'Ambrosio , Martin Hoferichter

Until now the focus within the direct search for supersymmetry has mainly been on flavour diagonal observables. Recently lepton flavour violating signals at future electron positron colliders have been studied. There is now an opportunity…

High Energy Physics - Phenomenology · Physics 2011-09-13 T. Hurth , W. Porod

We study possible impact of dark photons on lepton flavor phenomenology. We derive the constraints on non-diagonal dark photon couplings with leptons by analyzing corresponding contributions to lepton anomalous magnetic moments, rare lepton…

High Energy Physics - Phenomenology · Physics 2023-12-20 Alexey S. Zhevlakov , Dmitry V. Kirpichnikov , Valery E. Lyubovitskij

New Physics can show up in various well-known processes already studied in the Standard Model, in particular by modifying decay rates to some extent. In this work, I examine leptonic decays of $\Upsilon$ vector resonances of bottomonium…

High Energy Physics - Phenomenology · Physics 2011-07-19 M. A. Sanchis-Lozano

The persistent deviations observed in semileptonic $B$ decays, in particular the lepton flavor universality ratios $\mathcal{R}(D^{(*)})$ and $\mathcal{R}(\Lambda_c)$, provide intriguing hints of physics beyond the Standard Model (SM).…

High Energy Physics - Phenomenology · Physics 2025-10-14 Dris Boubaa , Shaaban Khalil

We propose a framework that links the origin of the Standard Model flavour hierarchies to the generation of asymmetric dark matter via leptogenesis. The key new ingredient is a gauged $SO(3)$ flavour symmetry acting on both the visible and…

High Energy Physics - Phenomenology · Physics 2026-05-21 Mattias Blennow , Enrique Fernandez-Martinez , David Garcia-Garcia , Javier M. Lizana