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Considering the recent experimental results on exclusive semileptonic $B$ meson decays showing sizable departure from their Standard Model prediction of lepton flavor universality and keeping ongoing and proposed non-standard Higgs searches…

High Energy Physics - Phenomenology · Physics 2019-07-25 Aritra Biswas , Dilip Kumar Ghosh , Sunando Kumar Patra , Avirup Shaw

Flavour changing neutral currents are suppressed in the Standard Model, making them a prime avenue to search for new physics. Although several measurements of the decay $B^{0}\to{}K^{\ast{}0}\mu^{+}\mu^{-}$ have shown deviations from the…

High Energy Physics - Experiment · Physics 2024-05-21 Mark Smith

The RK measurement by LHCb suggests non-standard lepton-universality violation (LUV) to occur in b to s l+ l- decays, with effects in muons rather than electrons. It is intriguing that a number of other measurements of b to s l+ l-…

High Energy Physics - Phenomenology · Physics 2017-08-29 Diego Guadagnoli

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 present the first global phenomenological fit of inclusive $\bar B\to X_c\ell\bar\nu$ observables to all available experimental data allowing for generic dimension-six New Physics interactions in the Weak Effective Theory. The fit…

High Energy Physics - Phenomenology · Physics 2026-04-21 Alexandre Carvunis , Gael Finauri , Paolo Gambino , Martin Jung , Sandro Mächler

The New Physics (NP) effects are studied in the rare baryonic decay $\Lambda_b \to \Lambda (\to p\pi^-)\ell^{+}\ell^{-}$, with unpolarized $\Lambda_b$ using most general model independent approach by introducing new axial(vector),…

High Energy Physics - Phenomenology · Physics 2021-10-27 Aqsa Nasrullah , Ishtiaq Ahmed , M. Jamil Aslam , Z. Asghar , Saba Shafaq

We present a global likelihood function in the space of dimension-six Wilson coefficients in the Standard Model Effective Field Theory (SMEFT). The likelihood includes contributions from flavour-changing neutral current B decays, lepton…

High Energy Physics - Phenomenology · Physics 2019-07-24 Jason Aebischer , Jacky Kumar , Peter Stangl , David M. Straub

We analyze the decays $K\to\pi\ell\nu$ and $P\to\ell\nu$ ($P=K,\pi$, $\ell=e,\,\mu$) using a low-energy Effective-Field-Theory approach to parametrize New Physics and study the complementarity with baryon $\beta$ decays. We then provide a…

High Energy Physics - Phenomenology · Physics 2017-02-01 Martín González-Alonso , Jorge Martin Camalich

We investigate a gauge extension of the Standard Model in light of the observed hints of lepton universality violation in $b \to c \ell \nu$ and $b \to s \ell^+ \ell^-$ decays at BaBar, Belle and LHCb. The model consists of an extended…

High Energy Physics - Phenomenology · Physics 2016-12-19 Sofiane M. Boucenna , Alejandro Celis , Javier Fuentes-Martin , Avelino Vicente , Javier Virto

The growing experimental indication of Lepton Flavour Universality Violation (LFUV) both in charged- and neutral-current semileptonic B-decays, has triggered many theoretical interpretations of such non-standard phenomena. Focusing on…

High Energy Physics - Phenomenology · Physics 2017-11-27 Ferruccio Feruglio , Paride Paradisi , Andrea Pattori

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

Lepton flavour universality (LFU) in B-decays is revisited by considering a class of semileptonic operators defined at a scale Lambda above the electroweak scale v. The importance of quantum effects, so far neglected in the literature, is…

High Energy Physics - Phenomenology · Physics 2017-01-11 Ferruccio Feruglio , Paride Paradisi , Andrea Pattori

The deviations with respect to the Standard Model (SM) that are currently observed in $b \to s \ell\ell$ transitions (the so-called flavour anomalies) can be interpreted in terms of different New Physics (NP) scenarios within a…

High Energy Physics - Phenomenology · Physics 2019-04-24 Marcel Algueró , Bernat Capdevila , Sébastien Descotes-Genon , Pere Masjuan , Joaquim Matias

In recent years, lepton flavour violating (LFV) decays are one of the most trending topics to probe new physics (NP). The latest results of LHCb have motivated us to study the LFV decays through b to s transition. The branching ratios,…

High Energy Physics - Phenomenology · Physics 2023-10-18 S. Biswas , S. Mahata , A. Biswas , S. Sahoo

Rare decays mediated by $b \to s \nu \bar \nu$ transitions have been reported by the Belle II experiment. The branching ratio of the decay $B^+ \to K^+ \nu \bar \nu$ is found to be enhanced with respect to the standard model value. If taken…

High Energy Physics - Phenomenology · Physics 2023-12-15 Rigo Bause , Hector Gisbert , Gudrun Hiller

A range of flavour physics observables show tensions with their corresponding Standard Model expectations: measurements of leptonic flavour-changing neutral current processes and ratios of semi-leptonic branching fractions involving…

High Energy Physics - Phenomenology · Physics 2018-03-28 Johannes Albrecht , Florian Bernlochner , Matthew Kenzie , Stefanie Reichert , David Straub , Alison Tully

The experimental measurements on flavour physics, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. This note summarises an analysis of the effects of the global fits to the Wilson…

High Energy Physics - Phenomenology · Physics 2021-06-15 Jorge Alda , Jaume Guasch , Siannah Penaranda

In this work we consider the implications of current $b \to s \ell^+ \ell^-$ ($\ell=e,\,\mu$) measurements on several $B \to K^* \tau^+ \tau^-$ observables under the assumption that the possible new physics can have both universal as well…

High Energy Physics - Phenomenology · Physics 2023-03-07 Neetu Raj Singh Chundawat

Radiative corrections to $B \to D \ell \nu_{\ell}$ decays can have an impact on predictions and measurements of the lepton universality ratios $\mathcal{R}(D^+)$ and $\mathcal{R}(D^0)$. These proceedings summarise a study on the comparison…

High Energy Physics - Phenomenology · Physics 2019-07-04 Suzanne Klaver

We investigate rare semileptonic \bar B -> \bar K^* l^+ l^- decays, providing a comprehensive treatment of theoretical uncertainties in the low-q^2 region as needed for interpreting current and future LHCb and B-factory data in terms of the…

High Energy Physics - Phenomenology · Physics 2015-06-12 Sebastian Jäger , Jorge Martin Camalich