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Related papers: Dispersive analysis of $\Lambda_b \to \Lambda(1520…

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In this work, we investigate the $\Lambda_b \to \Lambda$ transition form factors in the perturbative QCD (PQCD) approach, incorporating higher-twist light-cone distribution amplitudes (LCDAs). The resulted form factors show that…

High Energy Physics - Phenomenology · Physics 2026-02-03 Lei Yang , Jia-Jie Han , Qin Chang , Fu-Sheng Yu

The electromagnetic form factors of the $\Lambda$ hyperon in the time-like region are determined precisely through a dispersion-theoretical analysis of the world data for the cross section of the annihilation process $e^+e^-\to…

High Energy Physics - Phenomenology · Physics 2022-12-21 Yong-Hui Lin , Hans-Werner Hammer , Ulf-G. Meißner

Using $(2+1)$-flavor lattice QCD, we compute the 10 form factors describing the $\Lambda_b \to \Lambda$ matrix elements of the $b \to s$ vector, axial vector, and tensor currents. The calculation is based on gauge field ensembles generated…

High Energy Physics - Lattice · Physics 2021-08-12 William Detmold , Stefan Meinel

We present a method for parametrizing heavy meson semileptonic form factors using dispersion relations, and from it produce a two-parameter description of the B -> B elastic form factor. We use heavy quark symmetry to relate this function…

High Energy Physics - Phenomenology · Physics 2010-11-01 C. Glenn Boyd , Benjamin Grinstein , Richard F. Lebed

We present the first lattice-QCD determination of the form factors describing the semileptonic decays $\Lambda_b \to \Lambda_c^*(2595)\ell^-\bar{\nu}$ and $\Lambda_b \to \Lambda_c^*(2625)\ell^-\bar{\nu}$, where the $\Lambda_c^*(2595)$ and…

High Energy Physics - Lattice · Physics 2021-05-25 Stefan Meinel , Gumaro Rendon

We perform the first simultaneous dispersive analysis of the $B\to K$, $B\to K^*$, and $B_s\to \phi$ form factors. By means of an improved parametrization, we take into account the form factors' below-threshold branch cuts arising from…

High Energy Physics - Phenomenology · Physics 2025-01-08 Nico Gubernari , Méril Reboud , Danny van Dyk , Javier Virto

Based on the helicity method, formulae for the semileptonic transition of $\Lambda_b^0 \to \Lambda_c^+ \ell^- \bar \nu_\ell$ including lepton mass effects are derived. In order to calculate the form factors of the $\Lambda_b$ baryon…

High Energy Physics - Phenomenology · Physics 2025-03-14 Sara Rahmani

I review the parametrisation of the full set of $\Lambda_b\to\Lambda^* (1520)$ form factors in the framework of Heavy Quark Expansion, including next-to-leading-order $\mathcal{O}(\alpha_s)$ and, for the first time, next-to-leading-power…

High Energy Physics - Phenomenology · Physics 2021-03-30 Marzia Bordone

We study the differential decay rate for the rare decay $\Lambda_b\to \Lambda(1520)(\to NK)\ell^+\ell^-$ where $\ell$ is a light lepton, as this decay mode can provide new and complementary constraints on the Wilson coefficients in $b\to…

High Energy Physics - Phenomenology · Physics 2020-05-26 Sébastien Descotes-Genon , Martín Novoa-Brunet

Form factors are crucial theory input in order to extract $|V_{cb}|$ from $B \to D^{(*)}\ell\nu$ decays, to calculate the Standard Model prediction for ${\cal R}(D^{(*)})$ and to assess the impact of New Physics. In this context, the…

High Energy Physics - Phenomenology · Physics 2023-10-11 Marco Fedele , Monika Blanke , Andreas Crivellin , Syuhei Iguro , Ulrich Nierste , Silvano Simula , Ludovico Vittorio

We construct model-independent parametrizations of the individual QCD form factors relevant to Lambda_b --> Lambda_c l nu decays. These results follow from dispersion relations and analyticity, and incorporate an improvement in the…

High Energy Physics - Phenomenology · Physics 2008-02-03 C. Glenn Boyd , Richard F. Lebed

We present precision corrections to dispersion relation bounds on form factors in bottom hadron semileptonic decays and analyze their effects on parameterizations derived from these bounds. We incorporate QCD two-loop and nonperturbative…

High Energy Physics - Phenomenology · Physics 2009-10-30 C. Glenn Boyd , Benjamin Grinstein , Richard F. Lebed

$B_s^0\rightarrow D_s^{-}$ and $B_s^0\rightarrow D_s^{*-}$ weak transition form factors are estimated for the whole physical region with a method based on an instantaneous approximated Mandelstam formulation of transition matrix elements…

High Energy Physics - Phenomenology · Physics 2015-05-28 Xiang-Jun Chen , Hui-feng Fu , C. S. Kim , Guo-Li Wang

We present updates for our nonperturbative lattice QCD calculations to determine semileptonic form factors for exclusive $B\to \pi\ell\nu$, $B\to D \ell\nu$, $B_s\to K\ell \nu$, and $B_s\to D_s\ell\nu$ decays. Our calculation is based on…

High Energy Physics - Lattice · Physics 2019-12-23 Jonathan Flynn , Ryan Hill , Andreas Jüttner , Amarjit Soni , Justus Tobias Tsang , Oliver Witzel

We calculate the form factors of the $\Lambda_b\to\Lambda_c(2625)$ and $\Xi_b\to\Xi_c(2815)$ transitions, and additionally evaluate the corresponding semileptonic decays and the color-allowed two-body nonleptonic decays. In order to obtain…

High Energy Physics - Phenomenology · Physics 2023-02-27 Yu-Shuai Li , Xiang Liu

We examine the semileptonic $B \to D^{(*)} \ell \nu_\ell$ and $B \to \pi \ell \nu_\ell$ decays adopting the unitarity-based Dispersive Matrix (DM) method, which allows to determine the shape of the relevant hadronic form factors (FFs) in…

High Energy Physics - Phenomenology · Physics 2022-03-31 G. Martinelli , M. Naviglio , S. Simula , L. Vittorio

Dispersive constraints on the shape of the form factors which describe the exclusive decays B -> D^(*) l nu are derived by fully exploiting spin symmetry in the ground-state doublet of heavy-light mesons. The analysis includes all twenty…

High Energy Physics - Phenomenology · Physics 2009-10-30 I. Caprini , L. Lellouch , M. Neubert

We calculate the $\Lambda_b \to \Lambda_c \ell \nu$ form factors and decay rates for all possible $b\to c \ell\bar\nu$ four-Fermi interactions beyond the Standard Model, including nonzero charged lepton masses and terms up to order…

High Energy Physics - Phenomenology · Physics 2019-03-27 Florian U. Bernlochner , Zoltan Ligeti , Dean J. Robinson , William L. Sutcliffe

We compute the $\Lambda_b \to \Lambda$ transition form factors using light-cone sum rules based on $\Lambda$-baryon distribution amplitudes, including contributions up to twist--6. The analysis is performed for pseudoscalar, vector, and…

High Energy Physics - Phenomenology · Physics 2026-01-07 F. Mahmoudi , D. Mishra

We revisit light-cone sum rules with pion distribution amplitudes to determine the full set of local $B \to \pi$ form factors. To this end, we determine all duality threshold parameters from a Bayesian fit for the first time. Our results,…

High Energy Physics - Phenomenology · Physics 2021-07-21 Domagoj Leljak , Blaženka Melić , Danny van Dyk