English
Related papers

Related papers: Quark masses, CKM angles and Lepton Flavour Univer…

200 papers

Several experiments observed deviations from the Standard Model (SM) in the flavour sector: LHCb found a $4-5\,\sigma$ discrepancy compared to the SM in $b\to s\mu^+\mu^-$ transitions (recently supported by an Belle analysis) and CMS…

High Energy Physics - Phenomenology · Physics 2016-06-23 Andreas Crivellin

The flavor changing decays of heavy bottom quarks to the corresponding lighter quarks ($u$, $c$ and $s$) in various $B$-meson decays via charged current and neutral current semileptonic transitions have emerged as promising candidates to…

High Energy Physics - Phenomenology · Physics 2019-08-28 N Rajeev , Rupak Dutta , Suman Kumbhakar

We analyse the violations of lepton-flavour universality in the ratios B(P -> l nu)/B(P -> l' nu) using a general effective theory approach, discussing various flavour-symmetry breaking patterns of physics beyond the SM. We find that in…

High Energy Physics - Phenomenology · Physics 2009-11-05 Alberto Filipuzzi , Gino Isidori

Even though the LHC searches did not unveil the new physics particles so far, LHCb hints towards deviations from lepton flavor universality in exclusive decays based on the transition $b\to s\ell\ell$. In this proceeding, we present a new…

High Energy Physics - Phenomenology · Physics 2017-10-25 Olcyr Sumensari

We study the implications of single leptoquark extensions of the Standard Model (SM) under the assumption that their enhanced Yukawa sectors are invariant under global Abelian flavour symmetries already present in SM mass terms. Such…

High Energy Physics - Phenomenology · Physics 2022-10-19 Ivo de Medeiros Varzielas , Jim Talbert

The successful A4 family symmetry for leptons is applied to quarks, motivated by the quark-lepton assignments of SU(5). Realistic quark masses and mixing angles are obtained, in good agreement with data. In particular, we find a strong…

High Energy Physics - Phenomenology · Physics 2011-09-29 Ernest Ma , Hideyuki Sawanaka , Morimitsu Tanimoto

In light of recent measurements suggesting potential lepton flavor universality violations in semileptonic decays at collider experiments, this article provides a concise study of tree- and loop-level $B$-hadron semileptonic decays, $b \to…

High Energy Physics - Phenomenology · Physics 2025-02-05 Sonali Patnaik , Lopamudra Nayak , Rajeev Singh

The smallness of fermion masses and mixing angles has recently been been attributed to approximate global $U(1)$ symmetries, one for each fermion type. The parameters associated with these symmetry breakings are estimated here directly from…

High Energy Physics - Phenomenology · Physics 2009-12-30 Lawrence Hall , Steven Weinberg

We study the implications of an approximate $U(2)^5$ flavor symmetry at the TeV scale, under the assumption of new physics predominantly coupled to the third-generation fermions, focusing on the breaking of the $U(2)_\ell$ subgroup…

High Energy Physics - Phenomenology · Physics 2025-11-21 Sebastiano Covone , Pol Morell , Arianna Tinari

One of the most important discoveries in particle physics is the observation of nonzero neutrino masses, which dictates that the Standard Model (SM) is incomplete. Moreover, several pieces of evidence of lepton flavor universality violation…

High Energy Physics - Phenomenology · Physics 2022-09-15 J. Julio , Shaikh Saad , Anil Thapa

With the aim of linking natural supersymmetry to flavour physics, a model is proposed based on a family symmetry G \times U(1), where G is a discrete nonabelian subgroup of SU(2), with both F-term and (abelian) D-term supersymmetry…

High Energy Physics - Phenomenology · Physics 2015-06-16 Emilian Dudas , Gero von Gersdorff , Stefan Pokorski , Robert Ziegler

The flavor structure of quarks and leptons is not yet fully understood, but it hints a more fundamental theory of non-universal generations. We therefore propose a simple extension of the Standard Model by flipping (i.e., enlarging) the…

High Energy Physics - Phenomenology · Physics 2024-07-09 Duong Van Loi , Phung Van Dong , N. T. Duy , Nguyen Huy Thao

An extension of the Standard Model (SM) based on the non-Abelian discrete group $\Delta(27)$ is considered. The $\Delta(27)$ flavour symmetry is spontaneously broken only by gauge singlet scalar fields, therefore our model is free from any…

High Energy Physics - Phenomenology · Physics 2015-03-18 Mohammed Abbas , Shaaban Khalil

Flavor mixing is scrutinized at 1-loop in a SU(2)_L gauge theory of massive fermions. The main issue is to cope with kinetic-like, momentum (p^2) dependent effective interactions that arise at this order. They spoil the unitarity of the…

High Energy Physics - Phenomenology · Physics 2010-06-16 Bruno Machet

We consider the approximate U(2)^3 flavour symmetry exhibited by the quark sector of the Standard Model and all its possible breaking terms appearing in the quark Yukawa couplings. Taking an Effective Field Theory point of view, we…

High Energy Physics - Phenomenology · Physics 2015-06-05 Riccardo Barbieri , Dario Buttazzo , Filippo Sala , David M. Straub

Motivated by the recent LHCb announcement of a $3.1\sigma$ violation of lepton-flavor universality in the ratio $R_K=\Gamma(B\to K\mu^+\mu^-)/\Gamma(B\to K e^+ e^-)$, we present an updated, comprehensive analysis of the flavor anomalies…

High Energy Physics - Phenomenology · Physics 2021-09-28 Claudia Cornella , Darius A. Faroughy , Javier Fuentes-Martin , Gino Isidori , Matthias Neubert

Using an SU(3)-flavour symmetry breaking expansion between the strange and light quark masses, we determine how this constrains the extrapolation of baryon octet matrix elements and form factors. In particular we can construct certain…

High Energy Physics - Lattice · Physics 2021-12-09 J. M. Bickerton , A. N. Cooke , R. Horsley , Y. Nakamura , H. Perlt , D. Pleiter , P. E. L. Rakow , G. Schierholz , H. Stüben , R. D. Young , J. M. Zanotti

Recent anomalies in $B$-meson decays, such as deviations in $R_{D^{(*)}}$ and $B\to K\nu{\bar\nu}$, suggest possible lepton flavor universality violation and new exotic interactions. In this work, we explore these anomalies within a…

High Energy Physics - Phenomenology · Physics 2025-06-04 Bhubanjyoti Bhattacharya , Alakabha Datta , Gaber Faisel , Shaaban Khalil , Shibasis Roy

Very recently, a substantial $7\sigma$ deviation of the $W$-boson mass from the Standard Model (SM) prediction has been reported by the CDF collaboration. Furthermore, the Muon g-2 Experiment recently confirmed the longstanding tension in…

High Energy Physics - Phenomenology · Physics 2022-10-05 Talal Ahmed Chowdhury , Shaikh Saad

We study the phenomenological constraints and consequences in the flavor sector, of introducing a new fourth generation $\mathcal{Z}_{2}$ odd vector-like lepton doublet along with a Standard Model (SM) singlet scalar and an $SU(2)_{L}$…

High Energy Physics - Phenomenology · Physics 2018-06-05 Lobsang Dhargyal , Santosh Kumar Rai