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Related papers: LHCb anomalies from a natural perspective

200 papers

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 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

We discuss the implications of $b \to s \ell^+\ell^-$ measurements and their deviations with respect to the Standard Model predictions in a model-independent framework. We highlight in particular the impact of the recent updated…

High Energy Physics - Phenomenology · Physics 2022-10-14 T. Hurth , F. Mahmoudi , D. Martinez Santos , S. Neshatpour

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 LHCb measurements of certain ratios of decay modes testing lepton flavour non-universality might open an exciting world of new physics beyond the standard model. The latest LHCb measurements of R_K* offer some new insight beyond the…

High Energy Physics - Phenomenology · Physics 2017-11-29 T. Hurth , F. Mahmoudi , D. Martinez Santos , S. Neshatpour

There are some slight tensions with the SM predictions within the latest LHCb measurements. Besides the known anomaly in one angular observable of the rare decay B -> K* mu+ mu-, another small discrepancy recently occurred. The ratio R_K =…

High Energy Physics - Phenomenology · Physics 2014-12-09 T. Hurth , F. Mahmoudi , S. Neshatpour

Anomalies in (semi)leptonic $B$-meson decays present interesting patterns that might be revealing the shape of the new physics to come. In order to understand the experimental data, we explore symmetry arguments that lead to the hypothesis…

High Energy Physics - Phenomenology · Physics 2015-05-21 Rodrigo Alonso , Benjamín Grinstein , Jorge Martin Camalich

We scrutinize the recently further strengthened hints for new physics in semileptonic $B$-meson decays, focusing on the 'clean' ratios of branching fractions $R_K$ and $R_{K^\ast}$ and examining to which pattern of new effects they point…

High Energy Physics - Phenomenology · Physics 2018-12-05 Adrián Carmona , Florian Goertz

In recent times, one of the strongest hints of Physics Beyond the Standard Model (BSM) has been the anomaly in the ratios $R_D$ and $R_{D^\ast}$ measured in the charged current decays of $B$-mesons. In this work, we perform a comprehensive…

High Energy Physics - Phenomenology · Physics 2018-12-26 Aleksandr Azatov , Debjyoti Bardhan , Diptimoy Ghosh , Francesco Sgarlata , Elena Venturini

The measurements carried out at LEP and SLC projected us into the precision era of electroweak physics. This has also been relevant in the theoretical interpretation of LHCb and Belle measurements of rare $B$ semileptonic decays, paving the…

High Energy Physics - Phenomenology · Physics 2021-02-05 Lina Alasfar , Aleksandr Azatov , Jorge de Blas , Ayan Paul , Mauro Valli

We discuss the implications of the recently reported $R_K$ and $R_{K^*}$ anomalies, the lepton flavor non-universality in the $B\to K\ell^+\ell^-$ and $B\to K^*\ell^+\ell^-$. Using two sets of hadronic inputs of form factors, we perform a…

High Energy Physics - Phenomenology · Physics 2017-12-08 Wei Wang , Shuai Zhao

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

Flavor symmetries successfully explain lepton and quark masses and mixings yet it is usually hard to distinguish different models that predict the same mixing angles. Further experimental input could be available, if the agents of flavor…

High Energy Physics - Phenomenology · Physics 2015-09-03 Ivo de Medeiros Varzielas , Gudrun Hiller

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

The latest LHCb angular analysis of the rare decay B -> K* mu+ mu- shows some discrepancies from the SM up to the 3.7 sigma level. There is a consistent new physics explanation of these anomalies, while it is also reasonable that these…

High Energy Physics - Phenomenology · Physics 2014-04-15 T. Hurth , F. Mahmoudi

Normalizing the recent LHCb measurement of $\Lambda_b \to \Lambda_c \tau \bar\nu$ to the standard model (SM) prediction for the $\Lambda_b \to \Lambda_c \mu \bar\nu$ rate, instead of a LEP measurement, provides a more consistent comparison…

High Energy Physics - Phenomenology · Physics 2023-01-25 Florian U. Bernlochner , Zoltan Ligeti , Michele Papucci , Dean J. Robinson

The existing anomalies appearing in decays of the form $b\to s \ell^+ \ell^-$ constitute a possible hint for new physics. We point out that modifications to the SM results due to heavy neutrinos could account for the observed deviations…

High Energy Physics - Phenomenology · Physics 2017-06-30 Xiao-Gang He , German Valencia

It has been shown that the anomalies observed in $\bar B\to D^{(\ast)}\tau\bar\nu_\tau$ and $\bar B\to \bar K\ell^+\ell^-$ decays can be resolved by adding a single scalar or vector leptoquark to the Standard Model, while constraints from…

High Energy Physics - Phenomenology · Physics 2017-03-08 Xin-Qiang Li , Ya-Dong Yang , Xin Zhang

Measurements of the ratio of $B \to K^* \mu \mu $ to $B \to K^* e e $ branching fractions, $R_{K^*}$, by the LHCb collaboration strengthen the hints from previous studies with pseudoscalar kaons, $R_K$, for the breakdown of lepton…

High Energy Physics - Phenomenology · Physics 2018-02-12 Gudrun Hiller , Ivan Nisandzic

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