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Related papers: New Physics in Flavour Observables

200 papers

The persisting anomalous data in semileptonic B-decays point towards New Physics models exhibiting large sources of Lepton Flavour Universality Violation. In this work we generalise previous studies by considering frameworks which include…

High Energy Physics - Phenomenology · Physics 2018-11-14 Claudia Cornella , Ferruccio Feruglio , Paride Paradisi

Significant deviations from the Standard Model are observed in semileptonic charged and neutral-current B-decays, the muon magnetic moment, and the extraction of the Cabibbo angle. We propose that these deviations point towards a coherent…

High Energy Physics - Phenomenology · Physics 2021-08-11 David Marzocca , Sokratis Trifinopoulos

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

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

Several experiments revealed intriguing hints for lepton flavor universality (LFU) violating new physics (NP) in semi-leptonic $B$ meson decays, mainly in $b \to c \tau \nu$ and $b \to s \ell^+ \ell^-$ transitions at the $3-5\,\sigma$…

High Energy Physics - Phenomenology · Physics 2019-06-05 Andreas Crivellin , Francesco Saturnino

There are discrepancies between the experimental results and the Standard Model predictions, in the lepton flavor universality of the semileptonic $B$ decays: $B \to D^{(*)} \ell \nu$. As the new physics interpretations, new charged vector…

High Energy Physics - Phenomenology · Physics 2019-04-17 Syuhei Iguro , Yuji Omura , Michihisa Takeuchi

The LHCb measurement of the $\mu/e$ ratio $R_{K^*}$ indicates a deficit with respect to the Standard Model prediction, supporting earlier hints of lepton universality violation observed in the $R_K$ ratio. We show that the $R_K$ and…

High Energy Physics - Phenomenology · Physics 2019-03-26 Guido D'Amico , Marco Nardecchia , Paolo Panci , Francesco Sannino , Alessandro Strumia , Riccardo Torre , Alfredo Urbano

The $B$ meson semileptonic modes to $\rho(770)$ and $a_1 (1260)$ are useful to pin down possible non Standard Model effects. The 4d differential $\bar B \to \rho(\pi \pi) \ell^- \bar \nu_\ell$ and $ \bar B \to a_1 (\rho \pi) \ell^- \bar…

High Energy Physics - Phenomenology · Physics 2019-11-06 P. Colangelo , F. De Fazio , F. Loparco

Some recent $\tau$-physics results are presented from the BaBar and Belle experiments at the SLAC and KEK B factories, which produce copious numbers of $\tau$-lepton pairs. Measurements of the tau mass and lifetime allow to test lepton…

High Energy Physics - Experiment · Physics 2009-11-11 G. D. Lafferty

There are several anomalous measurements in the decays induced by the quark level transition $b \to s \mu^+ \mu^-$, which do not agree with the predictions of the Standard Model. These measurements could be considered as signatures of…

High Energy Physics - Phenomenology · Physics 2018-10-29 Gauhar Abbas , Ashutosh Kumar Alok , Shireen Gangal

We study the implications of the recent measurements of $R_K$ and $R_{K^*}$ by the LHCb collaboration. We do that by adopting a model-independent approach based on the Standard Model Effective Field Theory (SMEFT), in which the dominant new…

High Energy Physics - Phenomenology · Physics 2017-08-30 Alejandro Celis , Javier Fuentes-Martin , Avelino Vicente , Javier Virto

Besides being important to determine Standard Model parameters such as the CKM matrix elements $|V_{cb}|$ and $|V_{ub}|$, semileptonic $B$ decays seem also promising to reveal new physics (NP) phenomena, in particular in connection with the…

High Energy Physics - Phenomenology · Physics 2018-06-19 Pietro Colangelo , Fulvia De Fazio

Present measurements of b->c tau nu and b->u tau nu transitions differ from the standard model predictions of lepton flavor universality by almost 4sigma. We examine new physics interpretations of this anomaly. An effective field theory…

High Energy Physics - Phenomenology · Physics 2013-01-04 Svjetlana Fajfer , Jernej F. Kamenik , Ivan Nisandzic , Jure Zupan

Decays of the kind $B^0_{s,d}\to\ell^+\ell^-$ belong to the most favourable processes for probing the flavour structure of the Standard Model, with outstanding sensitivity to new (pseudo)-scalar contributions. While the branching ratio of…

High Energy Physics - Phenomenology · Physics 2018-05-16 Robert Fleischer

A recent proposal for explaining discrepancies in angular observables in the rare decay B --> K*mu+mu- with a gauged L_mu - L_tau current carried with it the prediction of lepton flavor universality violation in related B-meson decays. This…

High Energy Physics - Phenomenology · Physics 2015-10-21 Wolfgang Altmannshofer , Itay Yavin

If physics beyond the Standard Model (BSM) explains the $4.2\sigma$ difference between the Standard-Model and measured muon anomalous magnetic moment, $a_{\mu}$, minimal flavor violation predicts a shift in the analog quantity for the…

High Energy Physics - Phenomenology · Physics 2022-11-22 Andreas Crivellin , Martin Hoferichter , J. Michael Roney

We present an overview of recent work on flavour physics in the presence of a sequential fourth generation. We will discuss shortly the constraints on the new parameters and in the reminder present predictions for observables like Br(B_s ->…

High Energy Physics - Phenomenology · Physics 2010-12-07 Tillmann Heidsieck

Rare decays of the kind $B\to K^*\mu^+\mu^-$ and $B_s\to \phi\mu^+\mu^-$ are key players for testing the Standard Model. The current experimental data for their decay rates and angular observables show tensions with the theoretical…

High Energy Physics - Phenomenology · Physics 2025-04-23 Robert Fleischer , Martijn van Hamersveld , Tim Kortekaas , Anders Rehult , K. Keri Vos

$\tau$ is playing an important role in the current B-physics indications from experiments of lepton flavor universality violations(LFUV). This suggests it be given increasing attention theoretically in the coming years, given also the fact…

High Energy Physics - Phenomenology · Physics 2022-11-14 Amarjit Soni

The measurement of lepton universality parameters $R_{K^{(*)}}$ was updated by LHCb in December 2022, which indicated that the well-known anomalies in flavor-changing neutral current (FCNC) processes of B meson decays have faded away.…

High Energy Physics - Phenomenology · Physics 2023-10-31 Qiaoyi Wen , Fanrong Xu