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Related papers: Leptoquark models for the $B$-physics anomalies

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We show that a model with a scalar leptoquark of hypercharge $Y=1/6$ which includes the light right-handed neutrinos, can successfully describe both of the $B$-physics anomalies, $R_K^{\rm exp} < R_K^{\rm SM}$ and $R_D^{\rm exp} > R_D^{\rm…

High Energy Physics - Phenomenology · Physics 2016-12-28 Damir Bečirević , Svjetlana Fajfer , Nejc Košnik , Olcyr Sumensari

Even though the LHC searches did not unveil the new physics particles so far, LHCb hints towards deviations from lepton flavor universality in exclusive decays based on the transition $b\to s\ell\ell$. In this proceeding, we present a new…

High Energy Physics - Phenomenology · Physics 2017-10-25 Olcyr Sumensari

In view of the emerging hints for the violation of lepton flavour universality in several $B$-meson decays, we conduct a model-independent study (effective field theory approach) of several well-motivated new physics scenarios. Taking into…

High Energy Physics - Phenomenology · Physics 2021-04-02 J. Kriewald , C. Hati , J. Orloff , A. M. Teixeira

Lepton flavor universality in the Standard Model and hints of its violation in neutral ($R_K$) and charged currents $(R_{D^{(*)}})$ in $B$ decays are presented. We discuss model independent features as well as several leptoquark scenarios…

High Energy Physics - Phenomenology · Physics 2016-10-04 Nejc Kosnik

Motivated by the recent LHCb announcement of a $3.1\sigma$ violation of lepton-flavor universality in the ratio $R_K=\Gamma(B\to K\mu^+\mu^-)/\Gamma(B\to K e^+ e^-)$, we present an updated, comprehensive analysis of the flavor anomalies…

High Energy Physics - Phenomenology · Physics 2021-09-28 Claudia Cornella , Darius A. Faroughy , Javier Fuentes-Martin , Gino Isidori , Matthias Neubert

Motivated by additional experimental hints of Lepton Flavour Universality violation in B decays, both in charged- and in neutral-current processes, we analyse the ingredients necessary to provide a combined description of these phenomena.…

High Energy Physics - Phenomenology · Physics 2017-12-06 Dario Buttazzo , Admir Greljo , Gino Isidori , David Marzocca

One of the fundamental predictions of the Standard Model is Lepton Flavour Universality. Any deviation from this prediction would indicate the existence of physics beyond the Standard Model. Recent LHCb measurements present a pattern of…

High Energy Physics - Phenomenology · Physics 2018-08-21 Yoav Afik , Jonathan Cohen , Eitan Gozani , Enrique Kajomovitz , Yoram Rozen

Tests of lepton flavour universality in charged-current $B$ decays offer an excellent opportunity to test the Standard Model, and show hints of new physics in analyses performed by the LHCb, Belle and BaBar experiments. These proceedings…

High Energy Physics - Experiment · Physics 2019-07-03 Suzanne Klaver

Flavor symmetries that explain masses and mixings of the standard model fermions dictate flavor patterns for the couplings of scalar and vector leptoquarks to the standard model fermions. A generic feature is that couplings to…

High Energy Physics - Phenomenology · Physics 2017-01-04 Gudrun Hiller , Dennis Loose , Kay Schönwald

Motivated by the measurements of $b\to s\ell^+\ell^-$ transitions, including $R(K)$ and $R(K^*)$, we examine lepton flavour (universality) violation in $B$ decays and its connections to $\mu\to e\gamma$ in generic leptoquark models.…

High Energy Physics - Phenomenology · Physics 2018-02-07 Andreas Crivellin , Dario Mueller , Adrian Signer , Yannick Ulrich

We show that a modification of the model with a low energy scalar leptoquark state carrying hypercharge $Y=7/6$ allows to accommodate both $R_K<1$ and $R_{K^\ast}<1$, through loop effects, consistent with recent observations made at LHCb.…

High Energy Physics - Phenomenology · Physics 2018-06-01 Damir Bečirević , Olcyr Sumensari

Lepton Flavour Universality tests with semileptonic $\Lambda_b\to\Lambda_c^*$ decays are important to corroborate the present anomalies in the similar ratios $R_{D^{(*)}}$, and can provide complementary constraints on possible origins of…

High Energy Physics - Phenomenology · Physics 2018-07-31 Philipp Böer , Marzia Bordone , Elena Graverini , Patrick Owen , Marcello Rotondo , Danny van Dyk

We discuss the current status of lepton flavour universality observables in semileptonic charged and neutral current $B$ meson decays. We recapitulate the current experimental situation. Assuming the current tensions with the SM are of…

High Energy Physics - Phenomenology · Physics 2020-02-05 Nejc Košnik

Rare $K \to \pi \nu \bar \nu$ decays, being dominated by short distance contributions within the Standard Model (SM), open a window for New Physics (NP) searches at low energies. The $ K \to \pi \nu \bar\nu $ branching ratios are expected…

High Energy Physics - Phenomenology · Physics 2022-10-19 S. Fajfer , N. Košnik , L. Vale Silva

Right-handed neutrinos $\nu_R$ play a crucial role in flavor-changing neutral-current processes with missing energy, such as $b\to s + \slashed{E} $ and $d\to s + \slashed{E} $, where Belle-II reports unexpectedly large branching fraction…

High Energy Physics - Phenomenology · Physics 2025-03-31 Chuan-Hung Chen , Cheng-Wei Chiang , Leon M. G. de la Vega

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

Motivated by the recent experimental progress on the $R_{D^{(\ast)}}$ and $R_{K^{(\ast)}}$ anomalies in $B$-decays, we consider an extension of the Standard Model by a single vector leptoquark field. We study how one can achieve the…

High Energy Physics - Phenomenology · Physics 2020-12-14 J. Kriewald , C. Hati , J. Orloff , A. M. Teixeira

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

At the back of succeeding measurements of anomalies in semileptonic decays at LHCb and several collider experiments hinting at the possible violation of lepton flavor universality, we undertake a concise review of theoretical foundations of…

High Energy Physics - Phenomenology · Physics 2023-03-14 Sonali Patnaik , Rajeev Singh

In recent years, several deviations from the Standard Model predictions in semileptonic decays of $B$-meson might suggest the existence of new physics which would break the lepton-flavour universality. In this work, we have explored the…

High Energy Physics - Phenomenology · Physics 2020-05-20 Quan-Yi Hu , Ya-Dong Yang , Min-Di Zheng
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