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Related papers: New Physics in Flavour Observables

200 papers

The LHCb collaboration has recently presented their result on R_K = BR(B+ -> K+ mu+ mu-)/ BR(B+ -> K+ e+ e-) for the dilepton invariant mass bin m_{ll}^2 = 1-6 GeV^2 (l = mu, e). The measurement shows an intriguing 2.6 sigma deviation from…

High Energy Physics - Phenomenology · Physics 2015-06-22 Diptimoy Ghosh , Marco Nardecchia , S. A. Renner

Recent experimental results on angular observables in the rare decay $B\to K^*\mu^+\mu^-$ show significant deviations from Standard Model predictions. We investigate the possibility that these deviations are due to new physics. Combining…

High Energy Physics - Phenomenology · Physics 2014-09-05 Wolfgang Altmannshofer , David M. Straub

At present, there are several hints of lepton flavor non-universality. The LHCb Collaboration has measured $R_K\equiv{\cal B}(B^+ \to K^+ \mu^+ \mu^-)/{\cal B}(B^+ \to K^+ e^+ e^-)$, and the BaBar Collaboration has measured $R(D^{(*)})…

High Energy Physics - Phenomenology · Physics 2015-02-17 Bhubanjyoti Bhattacharya , Alakabha Datta , David London , Shanmuka Shivashankara

Rare semileptonic $b \to s \ell^+ \ell^-$ transitions provide some of the most promising frameworks to search for new physics effects. Recent analyses of these decays have indicated an anomalous behaviour in measurements of angular…

High Energy Physics - Phenomenology · Physics 2019-03-21 Andrea Mauri , Nicola Serra , Rafael Silva Coutinho

Experimental data have provided intriguing hints for the violation of lepton flavour universality (LFU), including $B\to D^{(*)}\tau\nu/B\to D^{(*)}\ell\nu$, the anomalous magnetic moment of the muon and $b\!\to\! s\ell^+\ell^-$ with a…

High Energy Physics - Phenomenology · Physics 2022-03-14 Alexandre Carvunis , Andreas Crivellin , Diego Guadagnoli , Shireen Gangal

We present results of global fits of all relevant experimental data on rare $b \to s$ decays. We observe significant tensions between the Standard Model predictions and the data. After critically reviewing the possible sources of…

High Energy Physics - Phenomenology · Physics 2015-09-30 Wolfgang Altmannshofer , David M. Straub

Several experiments reported hints for the violation of lepton flavor or lepton flavor universality in processes involving muons. Most prominently, there is the hint for a non-zero rate of the flavor violating Higgs decay $h \to \tau\mu$ at…

High Energy Physics - Phenomenology · Physics 2016-12-07 Wolfgang Altmannshofer , Marcela Carena , Andreas Crivellin

Transitions of the type $b \to s l^+ l^-$ are flavour changing neutral current processes where new physics can enter in competing loop diagrams with respect to the Standard Model contributions. In these decays several observables sensitive…

High Energy Physics - Experiment · Physics 2015-03-20 Nicola Serra

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

Several measurements on $R_D, R_{D^*}$, and $R_{J/ \psi}$ by the BaBar, Belle, and LHCb experiments show significant deviations from their Standard Model (SM) predictions, which illustrate the fact that the concept of lepton flavor…

High Energy Physics - Phenomenology · Physics 2023-01-30 Sambit Kumar Pusty , Dhiren Panda , Aishwarya Bhatta

The R_K measurement by LHCb suggests non-standard lepton non-universality (LNU) to occur in b -> s l+ l- transitions, with effects in muons rather than electrons. A number of other measurements of b -> s l+ l- transitions by LHCb and…

High Energy Physics - Phenomenology · Physics 2016-10-17 Diego Guadagnoli , Dmitri Melikhov , Meril Reboud

We review the current status and implications of the anomalies (i.e. deviations from the Standard Model predictions) in semi-leptonic $B$ meson decays, both in the charged and in the neutral current. In $b\to s\ell^+\ell^-$ transitions…

High Energy Physics - Phenomenology · Physics 2023-12-25 Bernat Capdevila , Andreas Crivellin , Joaquim Matias

One of the exciting results in flavor physics in recent times is the $R_D$/$R_{D^*}$ puzzle. The measurements of these flavor ratios performed by the B-factory experiments, BaBar and Belle, and the LHCb experiment are about $4\sigma$ away…

High Energy Physics - Phenomenology · Physics 2018-07-31 Ashutosh Kumar Alok , Dinesh Kumar , Suman Kumbhakar , S Uma Sankar

The LHC observed so far three deviations from the Standard Model (SM) predictions in flavour observables: LHCb reported anomalies in $B\to K^* \mu^+\mu^-$ and $R(K)=B\to K \mu^+\mu^-/B\to K e^+e^-$ while CMS found an excess in…

High Energy Physics - Phenomenology · Physics 2015-04-15 Andreas Crivellin , Giancarlo D'Ambrosio , Julian Heeck

We show that a combined analysis of $B\to K\nu\bar\nu$ and $B\to Kl^+l^-$ allows for new physics tests practically free of form factor uncertainties. Residual theory errors are at the level of several percent. Our study underlines the…

High Energy Physics - Phenomenology · Physics 2009-11-30 M. Bartsch , M. Beylich , G. Buchalla , D. -N. Gao

We analyse the possible presence of New Physics (NP) in the Flavour Sector and evaluate its potential for solving the tension between the experimental values of $\AJPKs$ and $\BTNu$ with respect to the Standard Model (SM) expectations.…

High Energy Physics - Phenomenology · Physics 2015-06-05 F. J. Botella , G. C. Branco , M. Nebot

The observable $\mathcal{R} \left( D^{(*)} \right) = \mathcal{B}\left( B^{0}\to D^{(*)-} \tau^{+} \nu_{\tau} \right) / \mathcal{B}\left( B^{0}\to D^{(*)-} \mu^{+} \nu_{\mu} \right)$ is a probe for Lepton Universality violation, so it is…

High Energy Physics - Experiment · Physics 2019-08-14 Federico Betti

We investigate the consequences of deviations from the Standard Model observed in $b\to s\mu\mu$ transitions for flavour-changing neutral-current processes involving down-type quarks and neutrinos, under generic assumptions concerning the…

High Energy Physics - Phenomenology · Physics 2021-05-21 Sébastien Descotes-Genon , Svjetlana Fajfer , Jernej F. Kamenik , Martín Novoa-Brunet

We benefit from a recent lattice determination of the full set of vector, axial and tensor form factors for the $\Lambda_b\to \Lambda^*_c(2595)\tau\bar\nu_\tau$ and $\Lambda^*_c(2625)\tau\bar\nu_\tau$ semileptonic decays to study the…

High Energy Physics - Phenomenology · Physics 2022-09-28 Meng-Lin Du , Neus Penalva , Eliecer Hernández , Juan Nieves

The deviations with respect to the Standard Model that are currently observed in $b \to s \ell\ell$ transitions, or $B$ anomalies, can be interpreted in terms of different New Physics (NP) scenarios within a model-independent effective…

High Energy Physics - Phenomenology · Physics 2019-09-04 Marcel Algueró , Bernat Capdevila , Sébastien Descotes-Genon , Pere Masjuan , Joaquim Matias