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Cabibbo-suppressed charged-current semileptonic decays of $Ξ_{b}$ baryons

Zhou Rui ^1,*, Zhi-Tian Zou ^1,†, Ya Li ^2,‡, and Ying Li^1,§

¹Department of Physics, Yantai University, Yantai 264005, China
²Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, China

^*Contact author: jindui1127@126.com
^†Contact author: zouzt@ytu.edu.cn
^‡Contact author: liyakelly@163.com
^§Contact author: liying@ytu.edu.cn

Phys. Rev. D 112, 113012 – Published 31 December, 2025

DOI: https://doi.org/10.1103/pynq-13c3

Abstract

We present the first perturbative QCD calculations of the $Ξ_{b} \to (Λ, Σ)$ transition form factors at leading order in $α_{s}$ , which govern the Cabibbo-suppressed semileptonic decays $Ξ_{b} \to (Λ, Σ) ℓ ν_{ℓ}$ with $ℓ = e$ , $μ$ , $τ$ . Using these form factors, we evaluate differential and integrated branching fractions and angular observables within the helicity formalism. The branching ratios are predicted to be of order $10^{- 4}$ for $Σ$ final states and $10^{- 5}$ for $Λ$ final states, making them accessible to ongoing experiments such as LHCb. Ratios of decay rates between $τ$ and $e$ channels are also provided, offering new probes of lepton-flavor universality. Lepton-mass effects are found to significantly impact the integrated angular observables. Furthermore, a combined analysis of $b \to u$ and $b \to c$ transitions in $Ξ_{b}$ decays yields subpercent precision for the ratios $R_{ℓ} (Σ / Ξ_{c})$ , enabling an independent determination of $| V_{u b} / V_{c b} |$ once the relevant decay-rate measurements become available.

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References (94)

S. Navas et al. (Particle Data Group), Review of particle physics, Phys. Rev. D 110, 030001 (2024).
S. Banerjee et al. (Heavy Flavor Averaging Group (HFLAV), Averages of $b$ -hadron, $c$ -hadron, and $τ$ -lepton properties as of 2023, arXiv:2411.18639.
X. W. Kang, B. Kubis, C. Hanhart, and U. G. Meißner, $B_{l 4}$ decays and the extraction of $| V_{u b} |$ , Phys. Rev. D 89, 053015 (2014).
Y. Sato et al. (Belle Collaboration), Measurement of the branching ratio of ${\bar{B}}^{0} \to D^{* +} τ^{-} {\bar{ν}}_{τ}$ relative to ${\bar{B}}^{0} \to D^{* +} ℓ^{-} {\bar{ν}}_{ℓ}$ decays with a semileptonic tagging method, Phys. Rev. D 94, 072007 (2016).
F. U. Bernlochner, Z. Ligeti, M. Papucci, and D. J. Robinson, Tensions and correlations in $| V_{c b} |$ determinations, Phys. Rev. D 96, 091503 (2017).
G. Ricciardi and M. Rotondo, Determination of the Cabibbo-Kobayashi-Maskawa matrix element $| V_{c b} |$ , J. Phys. G 47, 113001 (2020).
G. Ricciardi, Status of $| V_{c b} |$ and $| V_{u b} |$ CKM matrix elements, AIP Conf. Proc. 1701, 050014 (2016).
P. Gambino, M. Jung, and S. Schacht, The $V_{c b}$ puzzle: An update, Phys. Lett. B 795, 386 (2019).
G. Martinelli, S. Simula, and L. Vittorio, $| V_{c b} |$ and $R (D)^{(*)}$ ) using lattice QCD and unitarity, Phys. Rev. D 105, 034503 (2022).
G. Martinelli, S. Simula, and L. Vittorio, Exclusive determinations of $| V_{c b} |$ and $R (D^{*})$ through unitarity, Eur. Phys. J. C 82, 1083 (2022).
G. Martinelli, S. Simula, and L. Vittorio, Semileptonic $B \to D^{*}$ decays from light to $τ$ leptons: The extraction of the form factor $F_{2}$ from data, Eur. Phys. J. C 85, 242 (2025).
G. Martinelli, S. Simula, and L. Vittorio, Updates on the determination of $| V_{c b} |, R (D^{*})$ and $| V_{u b} | / | V_{c b} |$ , Eur. Phys. J. C 84, 400 (2024).
A. J. Buras, K. Gemmler, and G. Isidori, Quark flavour mixing with right-handed currents: An effective theory approach, Nucl. Phys. B843, 107 (2011).
A. Crivellin, Effects of right-handed charged currents on the determinations of $V_{u b}$ and $V_{c b}$ , Phys. Rev. D 81, 031301 (2010).
A. Crivellin and S. Pokorski, Can the differences in the determinations of $V_{u b}$ and $V_{c b}$ be explained by new physics?, Phys. Rev. Lett. 114, 011802 (2015).
F. U. Bernlochner, Z. Ligeti, and S. Turczyk, New ways to search for right-handed current in $B \to ρ ℓ \bar{ν}$ decay, Phys. Rev. D 90, 094003 (2014).
D. Bigi, P. Gambino, and S. Schacht, A fresh look at the determination of $| V_{c b} |$ from $B \to D^{*} ℓ ν$ , Phys. Lett. B 769, 441 (2017).
W. Altmannshofer and N. Lewis, Loop-induced determinations of $V_{u b}$ and $V_{c b}$ , Phys. Rev. D 105, 033004 (2022).
P. Colangelo and F. De Fazio, Tension in the inclusive versus exclusive determinations of $| V_{c b} |$ : A possible role of new physics, Phys. Rev. D 95, 011701 (2017).
S. Iguro and R. Watanabe, Bayesian fit analysis to full distribution data of $\bar{B} \to D^{(*)} ℓ \bar{ν} : | V_{cb} |$ determination and new physics constraints, J. High Energy Phys. 08 (2020) 006.
A. J. Buras and J. Girrbach, Towards the identification of new physics through quark flavour violating processes, Rep. Prog. Phys. 77, 086201 (2014).
I. I. Bigi, Is there a real difference between $| V_{q b} |_{excl}$ vs. $| V_{q b} |_{incl}$ from semi-leptonic $B$ decays?, arXiv:1507.01842.
A. Bansal, N. Mahajan, and D. Mishra, $\frac{| V_{u b} |}{| V_{c b} |}$ and quest for new physics, J. High Energy Phys. 02 (2022) 130.
G. Ricciardi, Theory: Semileptonic B decays and $| V_{x b} |$ update, Proc. Sci., BEAUTY2020 (2021) 031 [arXiv:2103.06099].
P. Gambino, A. S. Kronfeld, M. Rotondo, C. Schwanda, F. Bernlochner, A. Bharucha, C. Bozzi, M. Calvi, L. Cao, G. Ciezarek et al., Challenges in semileptonic $B$ decays, Eur. Phys. J. C 80, 966 (2020).
A. Biswas, S. Nandi, and I. Ray, Extractions of $| V_{u b} / V_{c b} |$ from a combined study of the exclusive $b \to u (c) ℓ^{-} {\bar{ν}}_{ℓ}$ decays, J. High Energy Phys. 07 (2023) 024.
R. Aaij et al. (LHCb Collaboration), First observation of the decay $B_{s}^{0} \to K^{-} μ^{+} ν_{μ}$ and Measurement of $| V_{u b} | / | V_{c b} |$ , Phys. Rev. Lett. 126, 081804 (2021).
R. Aaij et al. (LHCb Collaboration), Determination of the quark coupling strength $| V_{u b} |$ using baryonic decays, Nat. Phys. 11, 743 (2015).
W. Detmold, C. Lehner, and S. Meinel, $Λ_{b} \to p ℓ^{-} {\bar{ν}}_{ℓ}$ and $Λ_{b} \to Λ_{c} ℓ^{-} {\bar{ν}}_{ℓ}$ form factors from lattice QCD with relativistic heavy quarks, Phys. Rev. D 92, 034503 (2015).
R. N. Faustov and V. O. Galkin, Semileptonic decays of $Λ_{b}$ baryons in the relativistic quark model, Phys. Rev. D 94, 073008 (2016).
R. Dutta, $Λ_{b} \to (Λ_{c}, p) τ ν$ decays within standard model and beyond, Phys. Rev. D 93, 054003 (2016).
H. Y. Cheng, Nonleptonic weak decays of bottom baryons, Phys. Rev. D 56, 2799 (1997); 99, 079901(E) (2019).
D. Ebert, R. N. Faustov, and V. O. Galkin, Semileptonic decays of heavy baryons in the relativistic quark model, Phys. Rev. D 73, 094002 (2006).
R. L. Singleton, Semileptonic baryon decays with a heavy quark, Phys. Rev. D 43, 2939 (1991).
H. Y. Cheng and B. Tseng, 1/M corrections to baryonic form-factors in the quark model, Phys. Rev. D 53, 1457 (1996); 55, 1697(E) (1997).
M. A. Ivanov, V. E. Lyubovitskij, J. G. Korner, and P. Kroll, Heavy baryon transitions in a relativistic three quark model, Phys. Rev. D 56, 348 (1997).
M. A. Ivanov, J. G. Korner, V. E. Lyubovitskij, and A. G. Rusetsky, Charm and bottom baryon decays in the Bethe-Salpeter approach: Heavy to heavy semileptonic transitions, Phys. Rev. D 59, 074016 (1999).
F. Cardarelli and S. Simula, Analysis of the $Λ_{b} \to Λ_{c} ℓ ν_{ℓ}$ decay within a light front constituent quark model, Phys. Rev. D 60, 074018 (1999).
C. Albertus, E. Hernandez, and J. Nieves, Nonrelativistic constituent quark model and HQET combined study of semileptonic decays of $Λ_{b}$ and $Ξ_{b}$ baryons, Phys. Rev. D 71, 014012 (2005).
J. G. Korner, M. Kramer, and D. Pirjol, Heavy baryons, Prog. Part. Nucl. Phys. 33, 787 (1994).
J. Zhang, X. An, R. Sun, and J. Su, Probing new physics in semileptonic $Ξ_{b} \to Λ (Ξ_{c}) τ^{-} {\bar{ν}}_{τ}$ decays, Eur. Phys. J. C 79, 863 (2019).
H. W. Ke, G. Y. Fang, and Y. L. Shi, Study on the mixing of $Ξ_{c}$ and $Ξ_{c}^{'}$ by the transition $Ξ_{b} \to Ξ_{c}^{(')}$ , Phys. Rev. D 109, 073006 (2024).
R. Dutta, Phenomenology of $Ξ_{b} \to Ξ_{c} τ ν$ decays, Phys. Rev. D 97, 073004 (2018).
Z. Neishabouri and K. Azizi, Investigation of the semileptonic decays $Ξ_{b}^{(')} \to Ξ_{c}^{(')} ℓ {\bar{ν}}_{ℓ}$ , Phys. Rev. D 112, 054009 (2025).
K. Azizi, Y. Sarac, and H. Sundu, Light cone QCD sum rules study of the semileptonic heavy $Ξ_{Q}$ and $Ξ_{Q}^{'}$ transitions to $Ξ$ and $Σ$ baryons, Eur. Phys. J. A 48, 2 (2012).
R. N. Faustov and V. O. Galkin, Relativistic description of the $Ξ_{b}$ baryon semileptonic decays, Phys. Rev. D 98, 093006 (2018).
Z. Rui, Z. T. Zou, Y. Li, and Y. Li, Semileptonic baryon decays $Ξ_{b} \to Ξ_{c} ℓ^{-} {\bar{ν}}_{ℓ}$ in perturbative QCD, Phys. Rev. D 111, 113006 (2025).
C. D. Lu, Y. M. Wang, H. Zou, A. Ali, and G. Kramer, Anatomy of the pQCD approach to the baryonic decays $Λ_{b} \to p π, p K$ , Phys. Rev. D 80, 034011 (2009).
C. Q. Zhang, J. M. Li, M. K. Jia, and Z. Rui, Nonleptonic two-body decays of $Λ_{b} \to Λ_{c} π, Λ_{c} K$ in the perturbative QCD approach, Phys. Rev. D 105, 073005 (2022).
Z. Rui, C. Q. Zhang, J. M. Li, and M. K. Jia, Investigating the color-suppressed decays $Λ_{b} \to Λ ψ$ in the perturbative QCD approach, Phys. Rev. D 106, 053005 (2022).
Z. Rui, J. M. Li, and C. Q. Zhang, Estimates of exchange topological contributions and $C P$ -violating observables in $Λ_{b} \to Λ ϕ$ decay, Phys. Rev. D 107, 053009 (2023).
Z. Rui, J. M. Li, and C. Q. Zhang, Mixing effects of $η - η^{'}$ in $Λ_{b} \to Λ η^{(^{'})}$ decays, Phys. Rev. D 107, 093008 (2023).
Z. Rui, J. M. Li, and C. Q. Zhang, Estimates on the isospin-violating $Λ_{b} \to Σ^{0} ϕ, Σ^{0} J / ψ$ decays and the $Σ - Λ$ mixing, Phys. Rev. D 108, 033004 (2023).
Z. Rui and Z. T. Zou, Charmonium decays of beauty baryons in the perturbative QCD approach, Phys. Rev. D 109, 033013 (2024).
Z. Rui, Z. T. Zou, and Y. Li, Higher twist corrections to doubly-charmed baryonic B decays, J. High Energy Phys. 12 (2024) 159.
J. J. Han, Y. Li, H. n. Li, Y. L. Shen, Z. J. Xiao, and F. S. Yu, $Λ_{b} \to p$ transition form factors in perturbative QCD, Eur. Phys. J. C 82, 686 (2022).
J. J. Han, J. X. Yu, Y. Li, H. n. Li, J. P. Wang, Z. J. Xiao, and F. S. Yu, Establishing $C P$ violation in b-baryon decays, Phys. Rev. Lett. 134, 221801 (2025).
J. J. Han, J. X. Yu, Y. Li, H. n. Li, J. P. Wang, Z. J. Xiao, and F. S. Yu, $C P$ violation of two-body hadronic $Λ_{b}$ decays in the PQCD approach, Phys. Rev. D 112, 053007 (2025).
Y. Li, J. Chen, Y. X. Wang, and Z. T. Zou, Investigation of $Λ_{b} \to Λ_{c} ℓ^{-} {\bar{ν}}_{ℓ}$ decays in perturbative QCD approach, arXiv:2509.02257.
L. Yang, J. J. Han, Q. Chang, and F. S. Yu, The $Λ_{b} \to Λ$ transition form factors in perturbative QCD approach, arXiv:2508.18069.
M. Beneke, M. Garny, S. Jaskiewicz, J. Strohm, R. Szafron, L. Vernazza, and J. Wang, Next-to-leading power endpoint factorization and resummation for off-diagonal “gluon” thrust, J. High Energy Phys. 07 (2022) 144.
T. Feldmann, N. Gubernari, T. Huber, and N. Seitz, Contribution of the electromagnetic dipole operator $O_{7}$ to the ${\bar{B}}_{s} \to μ^{+} μ^{-}$ decay amplitude, Phys. Rev. D 107, 013007 (2023).
Z. L. Liu and M. Neubert, Factorization at subleading power and endpoint-divergent convolutions in $h \to γ γ$ decay, J. High Energy Phys. 04 (2020) 033.
Z. L. Liu, B. Mecaj, M. Neubert, and X. Wang, Factorization at subleading power and endpoint divergences in $h \to γ γ$ decay. Part II. Renormalization and scale evolution, J. High Energy Phys. 01 (2021) 077.
C. D. Lü, Y. L. Shen, C. Wang, and Y. M. Wang, Shedding new light on weak annihilation B-meson decays, Nucl. Phys. B990, 116175 (2023).
G. Bell, P. Böer, T. Feldmann, D. Horstmann, and V. Shtabovenko, $B_{c} \to η_{c}$ form factors at large recoil: Interplay of soft-quark and soft-gluon dynamics, J. High Energy Phys. 09 (2025) 098.
J. X. Yu, S. Cheng, J. J. Han, H. n. Li, and F. S. Yu, Tomography of high-twist proton structure through $e p$ elastic scattering, arXiv:2511.12589.
Y. Li and C. D. Lü, Recent anomalies in B physics, Sci. Bull. 63, 267 (2018).
A. Pich, Flavour anomalies, Proc. Sci., LHCP2019 (2019) 078 [arXiv:1911.06211].
S. Iguro, T. Kitahara, and R. Watanabe, Global fit to $b \to c τ ν$ anomalies as of Spring 2024, Phys. Rev. D 110, 075005 (2024).
P. Ball, V. M. Braun, and E. Gardi, Distribution amplitudes of the $Λ_{b}$ baryon in QCD, Phys. Lett. B 665, 197 (2008).
A. Ali, C. Hambrock, and A. Y. Parkhomenko, Light-cone wave functions of heavy baryons, Theor. Math. Phys. 170, 2 (2012).
A. Ali, C. Hambrock, A. Y. Parkhomenko, and W. Wang, Light-Cone distribution amplitudes of the ground state bottom baryons in HQET, Eur. Phys. J. C 73, 2302 (2013).
V. M. Braun, S. E. Derkachov, and A. N. Manashov, Integrability of the evolution equations for heavy-light baryon distribution amplitudes, Phys. Lett. B 738, 334 (2014).
Y. M. Wang and Y. L. Shen, Perturbative corrections to $Λ_{b} \to Λ$ form factors from QCD light-cone sum rules, J. High Energy Phys. 02 (2016) 179.
G. Bell, T. Feldmann, Y. M. Wang, and M. W. Y. Yip, Light-cone distribution amplitudes for heavy-quark hadrons, J. High Energy Phys. 11 (2013) 191.
X. Y. Han, J. Hua, X. Ji, C. D. Lü, W. Wang, J. Xu, Q. A. Zhang, and S. Zhao, A new method to access heavy meson lightcone distribution amplitudes from first-principle, Phys. Rev. D 111, L111503 (2025).
X. Y. Han, J. Hua, X. Ji, C. D. Lü, A. Schäfer, Y. Su, W. Wang, J. Xu, Y. Yang, J. H. Zhang et al., Calculation of heavy meson light-cone distribution amplitudes from lattice QCD, Phys. Rev. D 111, 034503 (2025).
W. Wang, J. Xu, Q. A. Zhang, and S. Zhao, Mass renormalization group of heavy meson light-cone distribution amplitude in QCD, arXiv:2411.07101.
Y. L. Liu and M. Q. Huang, Distribution amplitudes of Sigma and Lambda and their electromagnetic form factors, Nucl. Phys. A821, 80 (2009).
C. Bourrely, I. Caprini, and L. Lellouch, Model-independent description of $B \to π ℓ ν$ decays and a determination of $| V_{u b} |$ , Phys. Rev. D 79, 013008 (2009); 82, 099902(E) (2010).
T. Blake, S. Meinel, M. Rahimi, and D. van Dyk, Dispersive bounds for local form factors in $Λ_{b} \to Λ$ transitions, Phys. Rev. D 108, 094509 (2023).
Z. X. Zhao, Weak decays of heavy baryons in the light-front approach, Chin. Phys. C 42, 093101 (2018).
T. Gutsche, M. A. Ivanov, J. G. Körner, V. E. Lyubovitskij, and P. Santorelli, Heavy-to-light semileptonic decays of $Λ_{b}$ and $Λ_{c}$ baryons in the covariant confined quark model, Phys. Rev. D 90, 114033 (2014); 94, 059902(E) (2016).
F. U. Bernlochner, M. F. Sevilla, D. J. Robinson, and G. Wormser, Semitauonic b-hadron decays: A lepton flavor universality laboratory, Rev. Mod. Phys. 94, 015003 (2022).
F. U. Bernlochner, $B \to π τ {\bar{ν}}_{τ}$ decay in the context of type II 2HDM, Phys. Rev. D 92, 115019 (2015).
W. F. Duan, S. Iguro, X. Q. Li, R. Watanabe, and Y. D. Yang, On sum rules for semi-leptonic $b \to c$ and $b \to u$ decays, J. High Energy Phys. 07 (2025) 166.
B. Y. Cui, Y. K. Huang, Y. M. Wang, and X. C. Zhao, Shedding new light on $R (D_{(s)}^{*})$ and $| V_{c b} |$ from semileptonic $B_{(s)} \to D_{(s)}^{*} ℓ ν_{ℓ}$ decays, Phys. Rev. D 108, L071504 (2023).
F. U. Bernlochner, Z. Ligeti, D. J. Robinson, and W. L. Sutcliffe, New predictions for $Λ_{b} \to Λ_{c}$ semileptonic decays and tests of heavy quark symmetry, Phys. Rev. Lett. 121, 202001 (2018).
F. U. Bernlochner, Z. Ligeti, D. J. Robinson, and W. L. Sutcliffe, Precise predictions for $Λ_{b} \to Λ_{c}$ semileptonic decays, Phys. Rev. D 99, 055008 (2019).
M. Fedele, M. Blanke, A. Crivellin, S. Iguro, T. Kitahara, U. Nierste, and R. Watanabe, Impact of $Λ_{b} \to Λ_{c} τ ν$ measurement on new physics in $b \to c τ ν$ transitions, Phys. Rev. D 107, 055005 (2023).
Z. G. Wang, Analysis of the ${\frac{1}{2}}^{\pm}$ antitriplet heavy baryon states with QCD sum rules, Eur. Phys. J. C 68, 479 (2010).
V. Braun, R. J. Fries, N. Mahnke, and E. Stein, Higher twist distribution amplitudes of the nucleon in QCD, Nucl. Phys. B589, 381 (2000); Nucl. Phys.B607, 433(E) (2001).
V. M. Braun, S. E. Derkachov, G. P. Korchemsky, and A. N. Manashov, Baryon distribution amplitudes in QCD, Nucl. Phys. B553, 355 (1999).

Phys. Rev. D 112, 113012– Published 31 December, 2025

Vol. 112, Iss. 11 — 1 December 2025

Received 21 September 2025
Accepted 17 December 2025

DOI: https://doi.org/10.1103/pynq-13c3

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

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Cabibbo-suppressed charged-current semileptonic decays of $Ξ_{b}$ baryons

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Cabibbo-suppressed charged-current semileptonic decays of Ξb baryons

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Physics Subject Headings (PhySH)

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References (94)

Cabibbo-suppressed charged-current semileptonic decays of $Ξ_{b}$ baryons