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Related papers: A detailed study of the $\Lambda_b \to \Lambda \el…

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We calculate the $\Lambda_b \to \Lambda_c^*(2595) l \nu$ and $\Lambda_b \to \Lambda_c^*(2625) l \nu$ form factors and decay rates for all possible $b \to c l \bar\nu$ four-Fermi interactions in and beyond the Standard Model (SM), including…

High Energy Physics - Phenomenology · Physics 2022-03-07 Michele Papucci , Dean J. Robinson

We study the four-fold angular distribution of the semileptonic $\Lambda_b \to \Lambda_c^{+}(\to \Lambda \pi^{+})\ell^- \bar{\nu}_{\ell}$ decay and find out analytical expressions for various asymmetric and angular observables in the…

High Energy Physics - Phenomenology · Physics 2024-12-18 Soumitra Nandi , Shantanu Sahoo , Ria Sain

We present an analysis of the rare exclusive $B$ decays $B\to K\nu\bar\nu$ and $B\to K^{*}\nu\bar\nu$ within the Standard Model (SM), in a model-independent manner, and in a number of new physics (NP) models. Combining new form factor…

High Energy Physics - Phenomenology · Physics 2014-12-17 Andrzej J. Buras , Jennifer Girrbach-Noe , Christoph Niehoff , David M. Straub

This study examines the rare decay $B \to K_0^*(1430)\,\ell^+ \ell^-$ as a possible probe for new physics beyond the standard model (SM). We first analyze this channel within the SM and then include scalar leptoquark (LQ) contributions. We…

High Energy Physics - Phenomenology · Physics 2026-02-09 M. Dadashzadeh , K. Azizi

We revisit $\chi_{QJ}\to \ell^+\ell^-$ (with $J=0,1,2$ and $Q=b,c$) within the Standard Model (SM). The electro-magnetic contributions are given in color-singlet model with non-vanishing lepton masses at the leading order of $v$.…

High Energy Physics - Phenomenology · Physics 2015-06-04 Deshan Yang , Shuai Zhao

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

We investigate the $\Lambda_c \to \Lambda \ell^{+} \nu_\ell$ decay with a focus on potential new physics (NP) effects in the $\ell = \mu$ channel. We employ an effective Hamiltonian within the framework of the Standard Model Effective Field…

High Energy Physics - Phenomenology · Physics 2024-09-16 Fernando Alvarado , Luis Alvarez-Ruso , Eliecer Hernandez , Juan Nieves , Neus Penalva

In our previous work, based on the $SU(6)$ spin-flavor wave function, we regard $\Lambda$ and $p$ as composed of different quark-diquark configurations and established the Bethe-Salpeter (BS) equations of configurations for quark and scalar…

High Energy Physics - Phenomenology · Physics 2015-03-25 Y. Liu , L. -L. Liu , X. -H. Guo

Disentangling New Physics effects from the Standard Model requires a good understanding of all pieces that stem from the latter, especially the uncertainties that might plague the theoretical estimations within the Standard Model. In the…

High Energy Physics - Phenomenology · Physics 2016-11-16 Marco Ciuchini , Marco Fedele , Enrico Franco , Satoshi Mishima , Ayan Paul , Luca Silvestrini , Mauro Valli

We examine the measured rates for the decays $D\to K^{(*)}\ell\nu$, $B\to K^{(*)}\psi^{(\prime)}$ and $B\to K^*\gamma$ in a number of scenarios, in the framework of the heavy quark effective theory. We attempt to find a scenario in which…

High Energy Physics - Phenomenology · Physics 2014-11-17 W. Roberts , F. Ledroit

We use HPQCD's recent lattice QCD determination of $B \to K$ scalar, vector and tensor form factors to determine Standard Model differential branching fractions for $B \to K \ell^+\ell^-$, $B\to K \ell_1^+\ell_2^-$ and $B \to K\nu…

High Energy Physics - Phenomenology · Physics 2023-06-06 W. G. Parrott , C. Bouchard , C. T. H. Davies

Tests of lepton-universality as rate ratios in $b\to s \ell\ell$ transitions can be predicted very accurately in the Standard Model. The deficits with respect to expectations reported by the LHCb experiment in muon-to-electron ratios of the…

High Energy Physics - Phenomenology · Physics 2020-02-03 Li-Sheng Geng , Benjamín Grinstein , Sebastian Jäger , Jorge Martin Camalich , Xiu-Lei Ren , Rui-Xiang Shi

In this talk an analysis of the rare exclusive $B$ decays $B\to K\nu\bar\nu$ and $B\to K^{*}\nu\bar\nu$ within and beyond the Standard Model is presented. Combining new form factor determinations from lattice QCD with light-cone sum rule…

High Energy Physics - Phenomenology · Physics 2015-10-16 Christoph Niehoff

The semi-leptonic baryonic $b\to s$ decay, $\Lambda_b\rightarrow \Lambda \ell^+\ell^-$, has been studied and new angular observables and asymmetries have been proposed which can test the presence of new physics beyond the standard model.

High Energy Physics - Phenomenology · Physics 2015-11-04 Girish Kumar , Namit Mahajan

The rare decay $B\to\pi\ell^+\ell^-$ arises from $b\to d$ flavor-changing neutral currents and could be sensitive to physics beyond the Standard Model. Here, we present the first $ab$-$initio$ QCD calculation of the $B\to\pi$ tensor form…

We discuss the status of $b \to s \ell^+\ell^-$ decays in the post-$R_{K^{(*)}}$ era. The recent LHCb update of $R_K$ and $R_{K^*}$ measurements which are now compatible with the Standard Model, constrain new physics contributions to be…

High Energy Physics - Phenomenology · Physics 2023-10-10 T. Hurth , F. Mahmoudi , S. Neshatpour

The rare decays $\eta^{(\prime)}\to\ell^+\ell^-$, $\ell\in\{e,\mu\}$, are highly suppressed in the Standard Model, both by their chirality structure and the required loop attaching the lepton line to the $\eta^{(\prime)}\to\gamma^*\gamma^*$…

High Energy Physics - Phenomenology · Physics 2026-04-13 Noah Messerli , Martin Hoferichter , Bai-Long Hoid , Simon Holz , Bastian Kubis

We critically examine the potential to disentangle Standard Model (SM) and New Physics (NP) in $B \to K^* \mu^+\mu^-$ and $B\to K^* e^+ e^-$ decays, focusing on $(i)$ the LHCb anomaly, $(ii)$ the search for right-handed currents, and…

High Energy Physics - Phenomenology · Physics 2016-02-03 Sebastian Jäger , Jorge Martin Camalich

Taking into account the $\Lambda$ baryon distribution amplitudes and the most general form of the interpolating current of the $\Lambda_{b}$, the semileptonic $\Lambda_{b}\rar \Lambda \ell^+\ell^- $ transition is investigated in the…

High Energy Physics - Phenomenology · Physics 2010-05-19 T. M. Aliev , K. Azizi , M. Savci

We study the differential decay rate for the rare $\Lambda_b \to \Lambda (\to N \pi)\ell^+\ell^-$ transition, including a determination of the complete angular distribution, assuming unpolarized $\Lambda_b$ baryons. On the basis of a…

High Energy Physics - Phenomenology · Physics 2016-01-12 Philipp Böer , Thorsten Feldmann , Danny van Dyk