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Related papers: New physics in $b \to s e^+ e^-$?

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The search for New Physics (NP) beyond the Standard Model (SM) has been a central focus of particle physics, including in the context of $B$-meson decays involving $b \to s \ell \ell$ transitions. These transitions, mediated by…

High Energy Physics - Phenomenology · Physics 2024-08-08 F. Mahmoudi , Y. Monceaux

Indirect signs of new physics beyond the Standard Model may be appearing in $B \to K^{(*)}\mu^+\mu^-$ decays. If confirmed, the title question will be of paramount importance in determining the strategy for future colliders. We answer it by…

High Energy Physics - Phenomenology · Physics 2018-05-14 Tevong You

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

It is generally believed that the decay mode $B\to K^*\ell^+\ell^-$ is one of the best modes to search for physics beyond the standard model. The angular distribution enables the independent measurement of several observables as a function…

High Energy Physics - Phenomenology · Physics 2014-11-18 Rusa Mandal , Rahul Sinha , Diganta Das

Motivated by renewed evidence for new physics in $b \to s\ell\ell$ transitions in the form of LHCb's new measurements of theoretically clean lepton-universality ratios and the purely leptonic $B_s\to\mu^+\mu^-$ decay, we quantify the…

High Energy Physics - Phenomenology · Physics 2021-10-20 Li-Sheng Geng , Benjamín Grinstein , Sebastian Jäger , Shuang-Yi Li , Jorge Martin Camalich , Rui-Xiang Shi

The lepton flavor universality violating (LFUV) measurements $R_K$ and $R_{K^*}$ in $B$ meson decays can be accounted for in non-universal $Z'$ models. We constrain the couplings of these $Z'$ models by performing a global fit to correlated…

High Energy Physics - Phenomenology · Physics 2020-07-30 Ashutosh Kumar Alok , Amol Dighe , Shireen Gangal , Dinesh Kumar

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 di-leptons and di-neutrinos observed in the final states of flavor-changing neutral b decays provide an ideal platform for probing physics beyond the standard model. Although the latest measurements of $R_{K^{(*)}}$ agree well with the…

High Energy Physics - Phenomenology · Physics 2023-07-10 Nilakshi Das , Rupak Dutta

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

If physics beyond the standard model is present in B decays, experimental measurements seem to suggest that it principally affects those processes with significant b->s penguin amplitudes. It was recently argued that, in general, such…

High Energy Physics - Phenomenology · Physics 2009-11-10 David London , Joaquim Matias , Javier Virto

LHCb found hints for physics beyond the standard model in $B\to K^*\mu^+\mu^-$, $B\to K^*\mu^+\mu^-/B\to K^*e^+e^-$ and $B_s\to\phi\mu^+\mu^-$. In addition, the BABAR results for $B\to D^{(*)}\tau\nu$ and the CMS excess in…

High Energy Physics - Phenomenology · Physics 2016-04-20 Andreas Crivellin

We present allowed regions in the space of observables of certain non-leptonic B-meson decays that characterize these modes within the Standard Model. A future measurement of observables lying significantly outside of these regions would…

High Energy Physics - Phenomenology · Physics 2009-10-31 Robert Fleischer , Joaquim Matias

While electron and muon dipole moments are well-established precision probes of physics beyond the standard model, it is notoriously challenging to test realistic new-physics (NP) scenarios for the $\tau$ lepton. Constructing suitable…

High Energy Physics - Phenomenology · Physics 2026-05-06 Martin Hoferichter , Gabriele Levati

We discuss the status of $b \to s \ell^+\ell^-$ decays in the post-$R_{K^{(*)}}$ era. The recent LHCb update of $R_K$ and $R_{K^*}$ measurements which are now compatible with the Standard Model, constrain new physics contributions to be…

High Energy Physics - Phenomenology · Physics 2023-10-10 T. Hurth , F. Mahmoudi , S. Neshatpour

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

Motivated by a recent Belle~II measurement that suggests an excess in the rare decay $B \to K\, E_{\rm miss}$, and building upon our recent differential decay rate likelihood analysis of the existing experimental information, we investigate…

High Energy Physics - Phenomenology · Physics 2025-11-12 Patrick D. Bolton , Svjetlana Fajfer , Jernej F. Kamenik , Martín Novoa-Brunet

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

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

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 the measurements of observables involving $b \to s \mu\mu$ decays, namely $R_K$, $R_{K^*}$, $P_5^{\prime}$, and $B_s^\phi$, may be addressed by adding lepton-universality-violating new physics contributions to the effective…

High Energy Physics - Phenomenology · Physics 2021-03-25 Ashutosh Kumar Alok , Amol Dighe , Shireen Gangal , Dinesh Kumar