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Related papers: New Physics in the Flavour Sector

200 papers

In contrast with $B^0-\bar B^0$, $B_s-\bar B_s$ mixing where the standard model (SM) contributions overwhelm that of new physics beyond standard model (BSM), a measured relatively large $D^0-\bar D^0$ mixing where the SM contribution is…

High Energy Physics - Phenomenology · Physics 2015-06-18 Lian-Bao Jia , Ming-Gang Zhao , Hong-Wei Ke , Xue-Qian Li

The analysis of $b\to s\ell^+\ell^-$ flavor-changing neutral current decays is a powerful test of the Standard Model (SM). Due to the strong suppression of these modes in the SM, potential New Physics contributions can have a significant…

High Energy Physics - Experiment · Physics 2024-05-20 Leon Carus

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 study the implications of the observed excess in $B^+ \to K^+ \nu \bar{\nu}$ under the assumption of Rank-One Flavour Violation, i.e. that New Physics couples to a single specific direction in flavour space. By varying this direction we…

High Energy Physics - Phenomenology · Physics 2024-11-05 David Marzocca , Marco Nardecchia , Alfredo Stanzione , Claudio Toni

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

Flavour changing neutral currents are suppressed in the Standard Model, making them a prime avenue to search for new physics. Although several measurements of the decay $B^{0}\to{}K^{\ast{}0}\mu^{+}\mu^{-}$ have shown deviations from the…

High Energy Physics - Experiment · Physics 2024-05-21 Mark Smith

Flavor violating processes in the lepton sector have highly suppressed branching ratios in the standard model. Thus, observation of lepton flavor violation (LFV) constitutes a clear indication of physics beyond the standard model (BSM). We…

High Energy Physics - Phenomenology · Physics 2022-03-09 Alexey A. Petrov , Renae Conlin , Cody Grant

I review the current status of measurements involving semi-tauonic $B$ meson decay at the $B$-factories. I briefly discuss the experimental methods and highlight the importance of background contributions especially from poorly understood…

High Energy Physics - Experiment · Physics 2014-11-19 Vikas Bansal

Recent measurements of $b\to s\mu^+\mu^-$ processes at LHCb and BELLE have revealed tensions at the $2-3\,\sigma$ level between the Standard Model (SM) prediction and the experimental results in the channels $B\to K^*\mu^+\mu^-$ and…

High Energy Physics - Phenomenology · Physics 2017-05-24 Pere Arnan , Andreas Crivellin , Lars Hofer , Federico Mescia

If the mechanism of Supersymmetry breaking is not flavour blind, some flavour symmetry is likely to be needed to prevent excessive flavour changing neutral current effects. We discuss two flavour models (based respectively on a U(2) and on…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. Masiero , M. Piai , A. Romanino , L. Silvestrini

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

A global fit to quark flavour-physics data disfavours the Standard Model with 3.6 standard deviations and points towards new CP-violating physics in meson-antimeson mixing amplitudes. Tevatron data call for a new Bs-Bs-bar mixing phase and…

High Energy Physics - Phenomenology · Physics 2011-07-05 Ulrich Nierste

Current experimental data from the $g-2$ muon factor, seems to show the necessity of physics beyond the Standard Model (SM), since the difference between SM and experimental predictions is 2.6$\sigma $. In the framework of the General Two…

High Energy Physics - Phenomenology · Physics 2013-05-29 Rodolfo A. Diaz , R. Martinez , J. -Alexis Rodriguez

Recently, both ATLAS and CMS measured the decay $h\to\mu^+\mu^-$, finding a signal strength with respect to the Standard Model expectation of $1.2\pm0.6$ and $1.19\substack{+0.41+0.17\\-0.39 -0.16}$, respectively. This provides, for the…

High Energy Physics - Phenomenology · Physics 2021-07-14 Andreas Crivellin , Dario Mueller , Francesco Saturnino

These proceedings review the status of New Physics contributions to flavour violating $B$ decays. The anomalies in charged and neutral current $B$ decays related to lepton flavour universality violation have received a substantial amount of…

High Energy Physics - Phenomenology · Physics 2022-09-21 Monika Blanke

The recent measurement of $\mathcal{B}(B^+\to K^+\nu\bar{\nu})$ by Belle-II reveals a $2.8~\sigma$ deviation from the Standard Model (SM) prediction. Combining this with a prior Belle measurement of $\mathcal{B}(B^{0}\to…

High Energy Physics - Phenomenology · Physics 2024-10-14 Feng-Zhi Chen , Qiaoyi Wen , Fanrong Xu

The $3.1\sigma$ $R_K$ anomaly after Moriond 2021 and $3.3 \sigma$ $\Delta a_\mu$ from Fermilab Muon g-2 experiment implicate that the lepton flavor universality violation (LFUV) may play a role in the exploration of new physics. A Flavor…

High Energy Physics - Phenomenology · Physics 2021-04-09 Junmou Chen , Qiaoyi Wen , Fanrong Xu , Mengchao Zhang

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

The latest measurements of rare $b\to s$ decays in the LHCb experiment have led to results in tension with the predictions of the standard model (SM), including a tentative indication of the violation of lepton flavor universality. Assuming…

High Energy Physics - Phenomenology · Physics 2015-08-31 Chao-Jung Lee , Jusak Tandean

The quark sector of the Standard Model exhibits an approximate U(2)^3 flavour symmetry. This symmetry, broken in specific directions dictated by minimality, can explain the success of the Cabibbo-Kobayashi-Maskawa picture of flavour mixing…

High Energy Physics - Phenomenology · Physics 2017-08-23 Riccardo Barbieri , Dario Buttazzo , Filippo Sala , David M. Straub