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Related papers: A closer look at isodoublet vector leptoquark solu…

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Over the past years, experiments accumulated intriguing hints for new physics (NP) in flavor observables, namely in the anomalous magnetic moment of the muon ($a_\mu$), in $R(D^{(*)})={\rm Br}(B\to D^{(*)}\tau\nu)/{\rm Br}(B\to…

High Energy Physics - Phenomenology · Physics 2017-10-11 Andreas Crivellin , Dario Müller , Toshihiko Ota

It has been shown recently that the anomalies observed in $\bar B\to D^{(\ast)}\tau\bar\nu_\tau$ and $\bar B\to \bar K\ell^+\ell^-$ decays could be resolved with just one scalar leptoquark. Fitting to the current data on $R(D^{(\ast)})$…

High Energy Physics - Phenomenology · Physics 2016-09-21 Xin-Qiang Li , Ya-Dong Yang , Xin Zhang

We investigate the $R_{D}$ and $R_{D^*}$ anomalies in the context of non-minimal $SU(5)$, where Higgs sector is extended by adjoint 45-dimensional multiplet. One of the light spectrum of this model could be the scalar triplet leptoquark…

High Energy Physics - Phenomenology · Physics 2023-01-06 A. Ismael , S. Khalil

We present a thorough investigation of the vector leptoquark hypothesis for a combined explanation of the $B$-physics anomalies. We analyze this hypothesis from a twofold perspective, taking into account recent results from $B$-physics…

High Energy Physics - Phenomenology · Physics 2019-07-31 Claudia Cornella , Javier Fuentes-Martin , Gino Isidori

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

While the $S_3$ scalar leptoquark presents a possible tree-level explanation of the $b \to s \ell \ell$ flavour anomalies, it suffers from two conceptual problems which are often disregarded by model-builders. Firstly, the quantum numbers…

High Energy Physics - Phenomenology · Physics 2021-01-05 Joe Davighi , Matthew Kirk , Marco Nardecchia

We point out that in extended supersymmetric models such as supersymmetric left-right models, it is possible to have leptoquarks that explain the HERA high $Q^2$ anomaly without giving up R-parity conservation. The leptoquarks belong to…

High Energy Physics - Phenomenology · Physics 2009-10-30 B. Dutta , R. N. Mohapatra , S. Nandi

Leptoquarks (LQs) have been extensively studied in the context of $B$ anomalies. When $U(1)_{L_\mu-L_\tau}$ is introduced to a scalar LQ model with the LQ $S_1$ charged under the new symmetry, $S_1$ primarily couples to the third-generation…

High Energy Physics - Phenomenology · Physics 2023-10-05 Chuan-Hung Chen , Cheng-Wei Chiang

Motivated by the recent measurement of the lepton flavour nonuniversality ratio $R_{K^*}$ by the LHCb Collaboration, we study the implications of vector leptoquarks on the observed anomalies associated with the $\bar B \to \bar K^* l^+ l^-$…

High Energy Physics - Phenomenology · Physics 2018-08-01 Suchismita Sahoo , Rukmani Mohanta

We suggest three scalar leptoquarks, $S_1$, ${\tilde R}_2$, and $S_3$ which couple exclusively to the 3rd generation of leptons to explain the $B$ anomalies. The scalar singlet $S_1$ can explain $R(D^{(*)})$, while the doublet ${\tilde…

High Energy Physics - Phenomenology · Physics 2026-05-12 Jong-Phil Lee

We show that, up to plausible uncertainties in BR$(B_c\to \tau \nu)$, the $R_2$ leptoquark can simultaneously explain the observation of anomalies in $R_{K^{(*)}}$ and $R_{D^{(*)}}$ without requiring large couplings. The former is achieved…

High Energy Physics - Phenomenology · Physics 2019-09-04 Oleg Popov , Michael A. Schmidt , Graham White

We study the phenomenological constraints and consequences in the flavor sector, of introducing a new fourth generation $\mathcal{Z}_{2}$ odd vector-like lepton doublet along with a Standard Model (SM) singlet scalar and an $SU(2)_{L}$…

High Energy Physics - Phenomenology · Physics 2018-06-05 Lobsang Dhargyal , Santosh Kumar Rai

We consider lepton flavor violating Higgs decay, specifically $h \to \mu\tau$, in a leptoquark model. We introduce two scalar leptoquarks with the $SU(3)_c \times SU(2)_L \times U(1)_Y$ quantum numbers, $(3,2,7/6)$ and $(3,2,1/6)$, which do…

High Energy Physics - Phenomenology · Physics 2016-01-13 Seungwon Baek , Kenji Nishiwaki

In recent years, experiments revealed intriguing hints for new physics (NP) in semi-leptonic $B$ decays. Both in charged current processes, involving $b \to c \tau \nu$ transitions, and in the neutral currents $b\to s\ell^+\ell^-$, a…

High Energy Physics - Phenomenology · Physics 2020-10-19 Andreas Crivellin , Dario Müller , Francesco Saturnino

In this study, we investigate muon $g-2$, $R_{K^{(*)}}$, and $R_{D^{(*)}}$ anomalies in a specific model with one doublet, one triplet, and one singlet scalar leptoquark (LQ). When the strict limits from the $\ell' \to \ell \gamma$, $\Delta…

High Energy Physics - Phenomenology · Physics 2017-11-22 Chuan-Hung Chen , Takaaki Nomura , Hiroshi Okada

B-Physics anomalies have recently raised renewed interest in leptoquarks (LQ), predicted in several theoretical frameworks. Under simplifying but conservative assumptions, we show that the current limits from LHC searches together with the…

High Energy Physics - Phenomenology · Physics 2021-12-24 Georges Azuelos , Oliver Fischer , Sudip Jana

The measurements of the lepton flavor universality (LFU) in $\mathcal{B}({\bar{B}} \to D^{(\ast)} l \bar{\nu})$ indicate a significant deviation from the standard model prediction at a 3-4$\sigma$ level, revealing a violation of the LFU…

High Energy Physics - Phenomenology · Physics 2024-10-15 Syuhei Iguro , Teppei Kitahara

The vector leptoquark representation, $U_\mu = (3,1,2/3)$, was recently identified as an exceptional single mediator model to address experimental hints on lepton flavour universality violation in semileptonic $B$-meson decays, both in…

High Energy Physics - Phenomenology · Physics 2017-12-20 Luca Di Luzio , Admir Greljo , Marco Nardecchia

The Standard Model is extended by a SU(2)L singlet of vector leptoquarks. An additional SU(4) gauge symmetry between right-handed up quarks and right-handed leptons is introduced to render the model renormalizable. The arrangement is made…

High Energy Physics - Phenomenology · Physics 2008-11-26 Andreas Blumhofer , Bodo Lampe

Present measurements of b->c tau nu and b->u tau nu transitions differ from the standard model predictions of lepton flavor universality by almost 4sigma. We examine new physics interpretations of this anomaly. An effective field theory…

High Energy Physics - Phenomenology · Physics 2013-01-04 Svjetlana Fajfer , Jernej F. Kamenik , Ivan Nisandzic , Jure Zupan