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Related papers: Constraints on leptoquarks from lepton-flavour-vio…

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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

Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and…

High Energy Physics - Phenomenology · Physics 2021-01-01 Tomáš Husek , Kevin Monsálvez-Pozo , Jorge Portolés

Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and…

High Energy Physics - Phenomenology · Physics 2021-02-03 Tomas Husek , Kevin Monsalvez-Pozo , Jorge Portoles

Motivated by the recent experimental progress on the $R_{D^{(\ast)}}$ and $R_{K^{(\ast)}}$ anomalies in $B$-decays, we consider an extension of the Standard Model by a single vector leptoquark field. We study how one can achieve the…

High Energy Physics - Phenomenology · Physics 2020-12-14 J. Kriewald , C. Hati , J. Orloff , A. M. Teixeira

Motivated by the measurements of $b\to s\ell^+\ell^-$ transitions, including $R(K)$ and $R(K^*)$, we examine lepton flavour (universality) violation in $B$ decays and its connections to $\mu\to e\gamma$ in generic leptoquark models.…

High Energy Physics - Phenomenology · Physics 2018-02-07 Andreas Crivellin , Dario Mueller , Adrian Signer , Yannick Ulrich

The kaon sector is characterised by several processes which are under active investigation across different experiments. In this work, we present the global picture that emerges from a study of the different decay modes. We begin by…

High Energy Physics - Phenomenology · Physics 2022-09-27 G. D'Ambrosio , A. M. Iyer , F. Mahmoudi , S. Neshatpour

We confront the indications of lepton flavor universality (LFU) violation observed in semi-tauonic $B$ meson decays with new physics (NP) searches using high $p_T$ tau leptons at the LHC. Using effective field theory arguments we correlate…

High Energy Physics - Phenomenology · Physics 2016-11-15 Darius A. Faroughy , Admir Greljo , Jernej F. Kamenik

We study $b \to s \ell_1^+ \ell_2^-$ transitions, both for the lepton flavour conserving $\ell_1=\ell_2$ and violating case $\ell_1 \neq \ell_2$, in a minimal extension of the Standard Model proposed in [1]. In this framework, the Standard…

High Energy Physics - Phenomenology · Physics 2026-01-23 Pietro Colangelo , Fulvia De Fazio , Davide Milillo

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

Despite a large experimental effort, so far no evidence for flavour-violating decays of charged leptons such as $l_i\to l_j\gamma$ and $l_i\to l_j l_k l_k$ has been found. The absence of a signal puts very severe constraints on many…

High Energy Physics - Phenomenology · Physics 2017-05-11 Giovanni Marco Pruna , Adrian Signer

Inspired by the recent hints of lepton flavor universality violation in $b\to s\ell\ell$ and $b\to c\ell\nu$ transitions, we study lepton flavor violating exclusive $\Lambda_b\to\Lambda\ell_1^+\ell_2^-$ ($\ell_1\neq \ell_2$) decay, which is…

High Energy Physics - Phenomenology · Physics 2019-12-24 Diganta Das

Leptoquarks with masses between 2 TeV and 50 TeV are commonly invoked to explain deviations between data and Standard-Model (SM) predictions of several observables in the decays $b\to c\tau \bar\nu$ and $b\to s \ell^+\ell^-$ with…

High Energy Physics - Phenomenology · Physics 2023-11-27 Marco Fedele , Felix Wuest , Ulrich Nierste

We show that the scalar leptoquark Yukawa couplings generate a significant lepton flavour violation. We compute the light scalar leptoquark contributions to the branching ratios (Br) of the lepton flavour violating (LFV) decays $\ell \to…

High Energy Physics - Phenomenology · Physics 2010-09-21 Rachid Benbrik , Mohamed Chabab , Gaber Faisel

Anomalies in (semi)leptonic $B$-meson decays present interesting patterns that might be revealing the shape of the new physics to come. In order to understand the experimental data, we explore symmetry arguments that lead to the hypothesis…

High Energy Physics - Phenomenology · Physics 2015-05-21 Rodrigo Alonso , Benjamín Grinstein , Jorge Martin Camalich

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

Charged lepton flavor violation arises in the Standard Model Effective Field Theory at mass dimension six. The operators that induce neutrinoless muon and tauon decays are among the best constrained and are sensitive to new-physics scales…

High Energy Physics - Phenomenology · Physics 2024-04-15 Julian Heeck , Mikheil Sokhashvili

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

Lepton flavor violating processes are highly suppressed in the Standard Model. Therefore, if observed, lepton flavor violation would be a clear indication of new physics beyond the Standard Model. We study the process $e^+e^-\to\tau\mu$ at…

High Energy Physics - Phenomenology · Physics 2025-08-12 Pankaj Munbodh

Lepton flavor-violating processes offer interesting possibilities to probe new physics at multi-TeV scale. We discuss those in the framework of effective field theory, emphasizing the role of gluonic operators. Those operators are obtained…

High Energy Physics - Phenomenology · Physics 2017-08-09 Alexey A. Petrov , Dmitry V. Zhuridov

Charged lepton flavor violation provides a clear experimental signature in the search for physics beyond the Standard Model. In this work, we study the flavor-violating three-body tau decays $\tau^- \to \ell_i^- \ell_i^- \ell_j^+$ ($\ell_i…

High Energy Physics - Phenomenology · Physics 2026-03-19 G. Hernández-Tomé , J. P. Hoyos-Daza , O. G. Miranda , R. Sánchez-Vélez
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