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Related papers: LFU ratios in B decays using Lattice QCD and Unita…

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We investigate the semileptonic decays $\Lambda_{b} \to \Lambda_{c} \ell^- \bar{\nu}_\ell$ (with $\ell = e, \mu, \tau$) within the framework of perturbative QCD (pQCD). The six independent $\Lambda_b \to \Lambda_c$ transition form factors…

High Energy Physics - Phenomenology · Physics 2025-09-03 Ying Li , Jie Chen , Ya-Xin Wang , Zhi-Tian Zou

We discuss $B_c \to \eta_c$ and $B_c \to J/\psi$ semileptonic decays within the Standard Model (SM) and beyond. The relevant transition form factors, being the main source of theoretical uncertainties, are calculated in the sum rule…

High Energy Physics - Phenomenology · Physics 2019-06-26 Domagoj Leljak , Blazenka Melic , Monalisa Patra

A test of lepton flavor universality in B$^{\pm}$ $\to$ K$^{\pm}\mu^+\mu^-$ and B$^{\pm}$ $\to$ K$^{\pm}$e$^+$e$^-$ decays, as well as a measurement of differential and integrated branching fractions of a nonresonant B$^{\pm}$ $\to$…

High Energy Physics - Experiment · Physics 2024-07-08 CMS Collaboration

We present a model-independent global analysis of hadronic form factors for the semileptonic decays $b\rightarrow c\ell\nu$ that exploits lattice-QCD data, dispersion relations, and heavy-quark symmetries. The analysis yields predictions…

High Energy Physics - Phenomenology · Physics 2019-11-20 Thomas D. Cohen , Henry Lamm , Richard F. Lebed

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

The observable $\mathcal{R} \left( D^{(*)} \right) = \mathcal{B}\left( B^{0}\to D^{(*)-} \tau^{+} \nu_{\tau} \right) / \mathcal{B}\left( B^{0}\to D^{(*)-} \mu^{+} \nu_{\mu} \right)$ is a probe for Lepton Universality violation, so it is…

High Energy Physics - Experiment · Physics 2019-08-14 Federico Betti

We calculate the form factors for the $B \to D^*\ell\nu_\ell$ decay in 2+1 flavor lattice QCD. For all quark flavors, we employ the M\"obius domain-wall action, which preserves chiral symmetry to a good precision. Our gauge ensembles are…

High Energy Physics - Lattice · Physics 2024-06-05 Y. Aoki , B. Colquhoun , H. Fukaya , S. Hashimoto , T. Kaneko , R. Kellermann , J. Koponen , E. Kou

We report on a two-flavour lattice QCD study of the $B_s \to D_s$ and $B_s \to D^*_s$ transitions parameterized, in the heavy quark limit, by the form factors ${\cal G}$, and $h_{A_1}$, $h_{A_2}$ and $h_{A_3}$, respectively. In the search…

High Energy Physics - Lattice · Physics 2022-04-18 Benoît Blossier , Pierre-Henri Cahue , Jochen Heitger , Simone LaCesa , Jan Neuendorf , Savvas Zafeiropoulos

We propose a method to non-perturbatively calculate the forward-scattering matrix elements relevant to inclusive semi-leptonic B meson decays. Corresponding hadronic structure functions at unphysical kinematics are accessible through…

High Energy Physics - Lattice · Physics 2019-12-06 Shoji Hashimoto

Rare semileptonic $b \to s \ell^+ \ell^-$ transitions provide some of the most promising frameworks to search for new physics effects. Recent analyses of these decays have indicated an anomalous behaviour in measurements of angular…

High Energy Physics - Phenomenology · Physics 2019-03-21 Andrea Mauri , Nicola Serra , Rafael Silva Coutinho

Semi-leptonic $B$ decays provide promising channels to test the Standard Model, search for signs of new physics, or determine fundamental parameters like CKM matrix elements. We present an update on our calculation of short distance…

In a general framework, valid for any $H\to H'\ell^-\bar\nu_\ell$ semileptonic decay, we analyze the $d^2\Gamma/(d\omega d\cos\theta_\ell)$ and $d^2\Gamma/ (d\omega dE_\ell)$ distributions, with $\omega$ being the product of the hadron…

High Energy Physics - Phenomenology · Physics 2019-12-25 Neus Penalva , Eliecer Hernández , Juan Nieves

In recent times, several hints of lepton non-universality have been observed in semileptonic $B$ meson decays, both in the charged-current ($b \to c l \bar \nu_l$) and neutral-current ($b \to s ll $) transitions. Motivated by these…

High Energy Physics - Phenomenology · Physics 2019-01-16 Atasi Ray , Suchismita Sahoo , Rukmani Mohanta

Semileptonic $B_{(s)}$ decays are of great phenomenological interest because they allow to determine e.g. CKM matrix elements or test lepton flavor universality. Taking advantage of already existing lattice data, we demonstrate the analysis…

High Energy Physics - Lattice · Physics 2026-03-31 Anastasia Boushmelev , Matthew Black , Oliver Witzel

The most recent measurements of the observables $R_{D^{(*)}}$ are in tension with the Standard Model offering hints of New Physics in $b\rightarrow c \ell \bar{\nu}_{\ell}$ transitions. Motivated by these results, in this work we present an…

High Energy Physics - Phenomenology · Physics 2018-12-14 Giovanni Banelli , Robert Fleischer , Ruben Jaarsma , Gilberto Tetlalmatzi-Xolocotzi

We present a study of the rare baryonic decay $\Lambda_b \to \Lambda \tau^+ \tau^-$ as a probe of new physics (NP) coupled preferentially to third-generation fermions. Within the Standard Model, we evaluate the branching ratio and the…

High Energy Physics - Phenomenology · Physics 2026-04-27 Marzia Bordone , Gino Isidori , Christiane Mayer , Jan-Niklas Toelstede

In light of the LHCb observations about the $B_s \to D_s^{(*)}\ell \nu_\ell$ semileptonic decays, we study these channels within the Standard Model framework of covariant confined quark model. The necessary transition form factors are…

High Energy Physics - Phenomenology · Physics 2023-02-21 Nakul R. Soni , Aidos Issadykov , Akshay N. Gadaria , Zhomart Tyulemissov , Janaki J. Patel , Jignesh N. Pandya

The recent deviations of the experimental data on some parameters of the tree-level semileptonic $B$ and $B_c$ mesons decays from the standard model (SM) predictions indicate considerable violations of the lepton flavor universality, and as…

High Energy Physics - Phenomenology · Physics 2019-07-03 K. Azizi , Y. Sarac , H. Sundu

In this paper, we studied the semileptonic $B/B_s \to (D^{(*)},D_s^{(*)}) l\nu_l$ decays in the framework of the standard model (SM) , by employing the perturbative QCD (PQCD) factorization formalism combining with the lattice QCD inputs of…

High Energy Physics - Phenomenology · Physics 2020-06-24 Xue-Qing Hu , Su-Ping Jin , Zhen-Jun Xiao

We present a lattice quantum chromodynamics determination of the scalar and vector form factors for the $B_s \rightarrow D_s \ell \nu$ decay over the full physical range of momentum transfer. In conjunction with future experimental data,…

High Energy Physics - Lattice · Physics 2017-06-21 Christopher J Monahan , Heechang Na , Chris M Bouchard , G Peter Lepage , Junko Shigemitsu