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Related papers: Zero-Recoil Sum Rules for $\Lambda_b \to \Lambda_c…

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We calculate near zero recoil the order $\alpha_s$ corrections to the Bjorken and Voloshin sum rules that bound the $B\to D^{(*)}\ell\bar\nu$ form factors. These bounds are derived by relating the result of inserting a complete set of…

High Energy Physics - Phenomenology · Physics 2009-10-30 C. Glenn Boyd , Zoltan Ligeti , Ira Z. Rothstein , Mark B. Wise

Recent experimental progress on baryonic rare decays has spurred a deeper investigation on flavor-changing neutral current transitions in the baryon sector. Within the framework of QCD sum rules, we derive a complete set of form factors for…

High Energy Physics - Phenomenology · Physics 2024-12-31 Sheng-Qi Zhang , Cong-Feng Qiao

A lattice QCD calculation of the $\bar{B}\to Dl\bar{\nu}$ decay form factors is presented. We obtain the value of the form factor $h_+(w)$ at the zero-recoil limit $w=1$ with high precision by considering a ratio of correlation functions in…

High Energy Physics - Phenomenology · Physics 2008-11-26 Shoji Hashimoto , Aida X. El-Khadra , Andreas S. Kronfeld , Paul B. Mackenzie , Sinead M. Ryan , James N. Simone

We present the complete O(alpha_s^2) corrections to the Wilson coefficient of the unit operator in the zero-recoil sum rule for the B-->D* transition. We include both perturbative and power-suppressed nonperturbative effects in a manner…

High Energy Physics - Phenomenology · Physics 2010-11-23 Andrzej Czarnecki , Kirill Melnikov , Nikolai Uraltsev

We present a systematic discussion of Lambda_b -> Lambda transition form factors in the framework of soft-collinear effective theory (SCET). The universal soft form factor, which enters the symmetry relations in the limit of large recoil…

High Energy Physics - Phenomenology · Physics 2013-05-30 Thorsten Feldmann , Matthew W. Y. Yip

We study the hadronic matrix elements describing the $B_s \to D_s\ell \bar\nu_\ell$ decay in and beyond the Standard Model. By using the twisted mass QCD on the lattice with $N_f=2$ dynamical flavors we compute the normalization $\mathscr…

High Energy Physics - Lattice · Physics 2014-04-10 Mariam Atoui , Damir Becirevic , Vincent Morénas , Francesco Sanfilippo

In this write-up we review and update our recent lattice QCD calculation of $B \to K^*$, $B_s \to \phi$, and $B_s \to K^*$ form factors [arXiv:1310.3722]. These unquenched calculations, performed in the low-recoil kinematic regime, provide…

High Energy Physics - Lattice · Physics 2015-04-07 R. R. Horgan , Z. Liu , S. Meinel , M. Wingate

$B$ anomalies play a prominent role in Beyond the Standard Model (BSM) physics searches. In particular, the long standing tension between the inclusive and the exclusive determinations of the CKM matrix element $|V_{cb}|$ and the current…

High Energy Physics - Lattice · Physics 2022-12-21 Alejandro Vaquero

In this work, we analyze the semileptonic decay processes of $\Lambda_b \to \Lambda_c$ in the light-cone sum rule approach. In order to calculate the form factors of the $\Lambda_b$ baryon transition matrix element, we use the light-cone…

High Energy Physics - Phenomenology · Physics 2022-11-28 Hui-Hui Duan , Yong-Lu Liu , Ming-Qiu Huang

Studying the semileptonic decays of charmed particles is prominent in testing the standard model of particle physics. Motivated by recent experimental progress in weak decays of the charm baryon sector, we study the form factors of…

High Energy Physics - Lattice · Physics 2021-09-21 Huseyin Bahtiyar

We present an improved calculation of $B\to$ light vector form factors from light-cone sum rules, including one-loop radiative corrections to twist-2 and twist-3 contributions, and leading order twist-4 corrections. The total theoretical…

High Energy Physics - Phenomenology · Physics 2008-11-26 Patricia Ball , Roman Zwicky

We present the first unquenched lattice-QCD calculation of the hadronic form factors for the exclusive decay $\overline{B} \rightarrow D \ell \overline{\nu}$ at nonzero recoil. We carry out numerical simulations on fourteen ensembles of…

I discuss recent progress in lattice calculations of $B \to D^{(*)} \ell \nu$ form factors, important for the precision determination of $|V_{cb}|$ in the Standard Model (SM), and for testing SM expectations of lepton flavor universality in…

High Energy Physics - Lattice · Physics 2020-04-22 Andrew Lytle

We constrain the inverse moment of the $B$-meson light-cone distribution amplitude (LCDA), $\lambda_B$ in heavy quark effective theory, using form factor estimates from Lattice QCD collaboration. The estimation of the parameter $\lambda_B$…

High Energy Physics - Phenomenology · Physics 2023-11-27 Rusa Mandal , Soumitra Nandi , Ipsita Ray

We develop a new method in lattice QCD to calculate the form factor F(1) at zero recoil. This is the main theoretical ingredient needed to determine |V(cb)| from the exclusive decay anti-B --> D* lepton anti-neutrino. We introduce three…

High Energy Physics - Phenomenology · Physics 2014-11-17 Shoji Hashimoto , Andreas S. Kronfeld , Paul B. Mackenzie , Sinead M. Ryan , James N. Simone

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 present the first lattice-QCD calculation of the form factors governing the charm-baryon semileptonic decays $\Lambda_c \to \Lambda^*(1520)\ell^+\nu_\ell$. As in our previous calculation of the $\Lambda_b \to \Lambda^*(1520)$ form…

High Energy Physics - Lattice · Physics 2022-03-29 Stefan Meinel , Gumaro Rendon

We summarize our lattice QCD study of the form factor at zero recoil in the decay anti-B --> D* lepton anti-neutrino. After careful consideration of all sources of systematic uncertainty, we find, h_A1(1) =…

High Energy Physics - Lattice · Physics 2009-11-07 J. N. Simone , S. Hashimoto , A. S. Kronfeld , P. B. Mackenzie , S. M. Ryan

Lepton flavor universality violations in semileptonic $b \to c$ transitions have garnered attention over a decade. For $R_{H_c}={\rm{BR}}(H_b\to H_c \tau\bar\nu_\tau)/{\rm{BR}}(H_b\to H_c \ell\bar\nu_\ell)$ with $\ell$ being $e,\, \mu$, a…

High Energy Physics - Phenomenology · Physics 2025-05-20 Motoi Endo , Syuhei Iguro , Satoshi Mishima , Ryoutaro Watanabe

Upper and lower bounds are established on the Lambda_b -> Lambda_c semileptonic decay form factors by utilizing inclusive heavy-quark-effective-theory sum rules. These bounds are calculated to leading order in Lambda_QCD/m_Q and alpha_s.…

High Energy Physics - Phenomenology · Physics 2016-08-25 Cheng-Wei Chiang