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Related papers: Explaining the LHC flavour anomalies

200 papers

In the simplest examples of models with a discrete quark-lepton symmetry, an electroweak symmetry breaking sector with more than one Higgs doublet is necessary to obtain the correct mass relations between quarks and leptons. A two Higgs…

High Energy Physics - Phenomenology · Physics 2009-10-28 C. C. Lassig , R. R. Volkas

We show that the $2.4\sigma$ signal of the leptonic flavor violating (LFV) Higgs boson decay $h\to\mu\tau$, as observed by the CMS collaboration recently, can be explained by a certain class of two-Higgs doublet models that allow…

High Energy Physics - Phenomenology · Physics 2015-07-02 Dipankar Das , Anirban Kundu

Leptoquarks (LQs) have been extensively studied in the context of $B$ anomalies. When $U(1)_{L_\mu-L_\tau}$ is introduced to a scalar LQ model with the LQ $S_1$ charged under the new symmetry, $S_1$ primarily couples to the third-generation…

High Energy Physics - Phenomenology · Physics 2023-10-05 Chuan-Hung Chen , Cheng-Wei Chiang

We explore the interplay between $h(125) \to \tau\mu$ search at the LHC and $\tau \to \mu\gamma$ at the up and coming Belle~II experiment, in context of the general two Higgs doublet model with extra Yukawa couplings such as…

High Energy Physics - Phenomenology · Physics 2020-05-20 Wei-Shu Hou , Girish Kumar

The CMS collaboration has reported a possible lepton flavour violating (LFV) signal $h\to\mu\tau$. Whereas this does not happen in the standard model (SM), we point out that new physics responsible for this type of decay would, in general,…

High Energy Physics - Phenomenology · Physics 2016-08-03 Alper Hayreter , Xiao-Gang He , German Valencia

The Littlest Higgs model with T-parity (LHT) contains new sources of flavour and CP violation both in the quark and the lepton sector. They originate from the interactions of ordinary fermions with mirror fermions mediated by new gauge…

High Energy Physics - Phenomenology · Physics 2007-05-23 Andrzej J. Buras , Cecilia Tarantino

A minimal extension of the Standard Model (SM) featuring two scalar leptoquarks, an SU(2) doublet with hypercharge 1/6 and a singlet with hypercharge 1/3, is proposed as an economical benchmark model for studies of an interplay between…

High Energy Physics - Phenomenology · Physics 2023-11-13 Felipe F. Freitas , João Gonçalves , António P. Morais , Roman Pasechnik , Werner Porod

While the $S_3$ scalar leptoquark presents a possible tree-level explanation of the $b \to s \ell \ell$ flavour anomalies, it suffers from two conceptual problems which are often disregarded by model-builders. Firstly, the quantum numbers…

High Energy Physics - Phenomenology · Physics 2021-01-05 Joe Davighi , Matthew Kirk , Marco Nardecchia

In these proceedings we review the flavour phenomenology of 2HDMs with generic Yukawa structures. We first consider the quark sector and find that despite the stringent constraints from FCNC processes large effects in tauonic B decays are…

High Energy Physics - Phenomenology · Physics 2022-08-09 Andreas Crivellin , Christoph Greub , Ahmet Kokulu

We update phenomenological constraints on a Two Higgs Doublet Model with lepton flavour non-conserving Yukawa couplings. We review that $\tan \beta$ is ambiguous in such "Type III" models, and define it from the $\tau$ Yukawa coupling. The…

High Energy Physics - Phenomenology · Physics 2010-06-15 Sacha Davidson , Gerald Grenier

In recent years, evidence for lepton flavour universality violation beyond the Standard Model has been accumulated. In this context, a singly charged $SU(2)_L$ singlet scalar ($\phi^\pm$) is very interesting, as it can only have flavour…

High Energy Physics - Phenomenology · Physics 2021-05-03 Andreas Crivellin , Fiona Kirk , Claudio Andrea Manzari , Luca Panizzi

Leptoquarks (LQ) with couplings to the third generation of Standard Model (SM) quarks have been proposed as possible explanations of the flavour anomalies indicating the violation of lepton flavour universality (LFV). The CMS collaboration…

High Energy Physics - Experiment · Physics 2018-09-13 Johannes Haller

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

The Standard Model (SM) is amended by one generation of quarks and leptons which are vector-like (VL) under the SM gauge group but chiral with respect to a new $\mathrm{U}(1)_{3-4}$ gauge symmetry. We show that this model can simultaneously…

High Energy Physics - Phenomenology · Physics 2018-05-16 Stuart Raby , Andreas Trautner

Tree-level accidental symmetries are known to play a fundamental role in the phenomenology of the Standard Model (SM) for electroweak interactions. So far, no significant deviations from the theory have been observed in precision, flavour…

High Energy Physics - Phenomenology · Physics 2012-05-22 Elvira Cerveró , Jean-Marc Gérard

We consider an abelian extension of the Standard Model (SM) comprising a new gauge group $U(1)^\prime$, with the neutral gauge boson $Z^\prime$ having flavour violating couplings to quarks and leptons. The fermion content is the same as in…

High Energy Physics - Phenomenology · Physics 2025-11-27 Pietro Colangelo , Fulvia De Fazio , Davide Milillo

We carry out an exhaustive analysis of lepton flavor violating processes within the Simplest Little Higgs model. Its discovery could be expected from either $\mu\to e$ conversion in nuclei, $\mu\to e\gamma$ or $\mu\to3e$ decays. Then, the…

High Energy Physics - Phenomenology · Physics 2022-09-26 Enrique Ramirez , Pablo Roig

We explore $U(1)_{L_e-L_\mu}$ gauge extension of the Standard Model with particle content enlarged by three neutral fermions, of which the lightest one contributes to dark matter content of the Universe. The scalar sector is enriched with a…

High Energy Physics - Phenomenology · Physics 2026-05-29 Manas Kumar Mohapatra , Shivaramakrishna Singirala , Dhiren Panda , Rukmani Mohanta

A two Higgs doublet model (2HDM) is one of the minimal extensions of the Standard Model (SM), and it is well-known that the general setup predicts the flavor-violating phenomena, mediated by neutral Higgs interactions. Recently the CMS…

High Energy Physics - Phenomenology · Physics 2017-09-13 Yuji Omura , Eibun Senaha , Kazuhiro Tobe

Quark and lepton flavor signals are studied in four supersymmetric models, namely the minimal supergravity model, the minimal supersymmetric standard model with right-handed neutrinos, SU(5) supersymmetric grand unified theory with…

High Energy Physics - Phenomenology · Physics 2008-11-26 Toru Goto , Yasuhiro Okada , Tetsuo Shindou , Minoru Tanaka