English
Related papers

Related papers: On the anomalies in the latest LHCb data

200 papers

Recently the LHCb collaboration has confirmed the evidence for lepton flavour nonuniversality at the $3.1\sigma$ level via an updated measurement of $R_K$. In this work we analyse this evidence within a model-independent approach. We make…

High Energy Physics - Phenomenology · Physics 2021-12-15 T. Hurth , F. Mahmoudi , D. Martinez Santos , S. Neshatpour

In the Standard Model (SM), the rare transitions where a bottom quark decays into a strange quark and a pair of light leptons exhibit a potential sensitivity to physics beyond the SM. In addition, the SM embeds Lepton Flavour Universality…

High Energy Physics - Phenomenology · Physics 2018-02-14 Bernat Capdevila , Andreas Crivellin , Sébastien Descotes-Genon , Joaquim Matias , Javier Virto

In view of both the latest LHCb measurement of $R_{K^{(*)}}$ and the new $2.8\sigma$ deviation reported by Belle II on $B^{+}\to K^{+}\nu\bar{\nu}$ decays, we present a fit to the $B$ meson anomalies for various one and two dimensional…

High Energy Physics - Phenomenology · Physics 2024-02-19 Peter Athron , R. Martinez , Cristian Sierra

We critically examine the potential to disentangle Standard Model (SM) and New Physics (NP) in $B \to K^* \mu^+\mu^-$ and $B\to K^* e^+ e^-$ decays, focusing on $(i)$ the LHCb anomaly, $(ii)$ the search for right-handed currents, and…

High Energy Physics - Phenomenology · Physics 2016-02-03 Sebastian Jäger , Jorge Martin Camalich

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 quantify the ability of B-Factories to observe supersymmetric contributions to the rare decays B -> X_s \gamma and B -> X_s l+ l-. A global fit to the Wilson coefficients which contribute to these decays is performed from Monte Carlo…

High Energy Physics - Phenomenology · Physics 2009-10-28 JoAnne L. Hewett , James D. Wells

Using the general, model independent form of the effective Hamiltonian, the general expressions of the longitudinal, normal and transversal polarization asymmetries for (l^-) and (l^+) and combinations of them for the exclusive (B -> K l^+…

High Energy Physics - Phenomenology · Physics 2009-11-07 T. M. Aliev , M. K. Cakmak , A. Ozpineci , M. Savci

We study lepton polarization asymmetries in the (Lambda_b -> Lambda l^+ l^-) decay using the most general model independent effective Hamiltonian. The dependence of the lepton polarizations and their combinations on the new Wilson…

High Energy Physics - Phenomenology · Physics 2011-03-23 T. M. Aliev , A. Ozpineci , M. Savci

The LHCb Collaboration's measurement of R_K = B(B+ -> K+ mu+ mu-)/B(B+ -> K+ e+e-) lies 2.6 sigma below the Standard Model prediction. Several groups suggest this deficit to result from new lepton non-universal interactions of muons. But…

High Energy Physics - Phenomenology · Physics 2015-03-11 Sheldon L. Glashow , Diego Guadagnoli , Kenneth Lane

We provide a detailed analysis of the impact of the newly measured optimised observables in the B -> K* mu+ mu- decay by the LHCb experiment. The analysis is performed in the MSSM, both in the context of the usual constrained scenarios, and…

High Energy Physics - Phenomenology · Physics 2014-06-20 F. Mahmoudi , S. Neshatpour , J. Virto

We present a critical assessment of the present $B$ anomalies in the exclusive $b \to s \ell\ell$ mode based on the QCD factorisation (QCDf) approach. In particular, we analyse the impact of different local form factor calculations and of…

High Energy Physics - Phenomenology · Physics 2025-12-16 T. Hurth , F. Mahmoudi , Y. Monceaux , S. Neshatpour

Flavour changing neutral current decays mediated by b --> s l^+ l^- were under experimental investigation at B-factories and the Tevatron during the last decade and the final analysis are expected soon. Moreover, new data has been released…

High Energy Physics - Phenomenology · Physics 2011-12-16 Christoph Bobeth

While the LHC did not observe direct evidence for physics beyond the standard model, indirect hints for new physics were uncovered in the flavour sector in the decays $B\to K^*\mu^+\mu^-$, $B\to K\mu^+\mu^-/B\to Ke^+e^-$,…

High Energy Physics - Phenomenology · Physics 2016-06-22 Andreas Crivellin

We study the Standard Model and the new physics predictions for the lepton-flavour-universality violating (LFUV) ratios in various $b\to s \ell^+\ell^-$ channels with scalar, pseudoscalar, vector, axial-vector, and $\Lambda$ baryon final…

High Energy Physics - Phenomenology · Physics 2022-03-31 Faisal Munir Bhutta , Zhuo-Ran Huang , Cai-Dian Lü , M. Ali Paracha , Wenyu Wang

Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios $R_K$ and $R_{K^*}$. The currently observed values align with the predictions of the standard model. In light of these recent updates, our…

High Energy Physics - Phenomenology · Physics 2024-10-04 Juhi Vardani , Ria Sain

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

The $B\to K^*\mu\mu$ decay exhibits deviations with respect to Standard Model expectations and the measurement of the ratio $R_K$ hints at a violation of lepton-flavour universality in $B\to K\ell\ell$ transitions. Both effects can be…

High Energy Physics - Phenomenology · Physics 2017-09-13 Bernat Capdevila , Sebastien Descotes-Genon , Joaquim Matias , Javier Virto

In the absence of direct evidence for New Physics at present LHC energies, the focus is set on the anomalies and discrepancies recently observed in rare $b \to s\ell\ell$ transitions which can be interpreted as indirect hints. Global fits…

High Energy Physics - Phenomenology · Physics 2018-06-19 Bernat Capdevila , Sebastien Descotes-Genon , Lars Hofer , Joaquim Matias

In recent years, intriguing hints for the violation of Lepton Flavour Universality (LFU) have been accumulated in semileptonic $B$ decays, both in the neutral-current transitions $b\to s\ell^+\ell^-$ (i.e., $R_K$ and $R_{K^*}$) and the…

High Energy Physics - Phenomenology · Physics 2018-05-09 Bernat Capdevila , Andreas Crivellin , Sébastien Descotes-Genon , Lars Hofer , Joaquim Matias

The anomalies in rare $B$ decays endure. We present results of an updated global analysis that takes into account the latest experimental input -- in particular the recent results on $R_K$ and BR$(B_s \to \mu^+\mu^-)$ -- and that…

High Energy Physics - Phenomenology · Physics 2021-11-17 Wolfgang Altmannshofer , Peter Stangl