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Influence of invisible light particles on $Λ_{b} \to Λ E_{miss}$

Department of Physics, Guangxi Normal University, Guilin 541004, Guangxi, China

^*Contact author: huquanyi@gxnu.edu.cn

Phys. Rev. D 112, 095007 – Published 7 November, 2025

DOI: https://doi.org/10.1103/zp29-r1l6

Abstract

In this work, we study the contribution of invisible light particles to $Λ_{b} \to Λ E_{miss}$ , particularly the three-body decays $Λ_{b} \to Λ ϕ \bar{ϕ}$ and $Λ_{b} \to Λ ψ \bar{ψ}$ . The differential branching ratio of $Λ_{b} \to Λ E_{miss}$ and the $q^{2}$ -dependent longitudinal polarization asymmetry of $Λ$ in scenarios explaining the Belle II excess are presented. In the chiral basis, we investigate the correlations between $B (B \to K E_{miss})$ and $B (Λ_{b} \to Λ E_{miss})$ , as well as between $B (B \to K E_{miss})$ and $P_{L}^{Λ}$ , in eight distinct new physics scenarios. We find that the $P_{L}^{Λ}$ can be used to distinguish the chirality of the hadronic current part in the effective operators, which is similar to the cases in the two-body decays $Λ_{b} \to Λ ϕ$ and $Λ_{b} \to Λ V$ .

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References (59)

S. L. Glashow, J. Iliopoulos, and L. Maiani, Weak interactions with lepton-hadron symmetry, Phys. Rev. D 2, 1285 (1970).
Belle-II Collaboration, Evidence for $B^{+} \to K^{+} ν \bar{ν}$ decays, Phys. Rev. D 109, 112006 (2024).
Q.-Y. Hu, Are the new particles heavy or light in $b \to s E_{miss}$ ?, Eur. Phys. J. C 85, 556 (2025).
P. Athron, R. Martinez, and C. Sierra, $B$ meson anomalies and large $B^{+} \to K^{+} ν \bar{ν}$ in non-universal $U (1)^{'}$ models, J. High Energy Phys. 02 (2024) 121.
R. Bause, H. Gisbert, and G. Hiller, Implications of an enhanced $B \to K ν \bar{ν}$ branching ratio, Phys. Rev. D 109, 015006 (2024).
L. Allwicher, D. Becirevic, G. Piazza, S. Rosauro-Alcaraz, and O. Sumensari, Understanding the first measurement of $B (B \to K ν \bar{ν})$ , Phys. Lett. B 848, 138411 (2024).
M. Abdughani and Y. Reyimuaji, Constraining light dark matter and mediator with $B^{+} \to K^{+} ν \bar{ν}$ data, Phys. Rev. D 110, 055013 (2024).
C.-H. Chen and C.-W. Chiang, Flavor anomalies in leptoquark model with gauged $U (1)_{L_{μ} - L_{τ}}$ , Phys. Rev. D 109, 075004 (2024).
X.-G. He, X.-D. Ma, and G. Valencia, Revisiting models that enhance $B^{+} \to K^{+} ν \bar{ν}$ in light of the new Belle II measurement, Phys. Rev. D 109, 075019 (2024).
A. Datta, D. Marfatia, and L. Mukherjee, $B \to K ν \bar{ν}$ , MiniBooNE and muon $g - 2$ anomalies from a dark sector, Phys. Rev. D 109, L031701 (2024).
W. Altmannshofer, A. Crivellin, H. Haigh, G. Inguglia, and J. Martin Camalich, Light new physics in $B \to K^{(*)} ν \bar{ν}$ ?, Phys. Rev. D 109, 075008 (2024).
D. McKeen, J. N. Ng, and D. Tuckler, Higgs portal interpretation of the Belle II $B^{+} \to K^{+} ν ν$ measurement, Phys. Rev. D 109, 075006 (2024).
K. Fridell, M. Ghosh, T. Okui, and K. Tobioka, Decoding the $B \to K ν ν$ excess at Belle II: Kinematics, operators, and masses, Phys. Rev. D 109, 115006 (2024).
S.-Y. Ho, J. Kim, and P. Ko, Recent $B^{+} \to K^{+} ν \bar{ν}$ excess and Muon $g - 2$ illuminating light dark sector with Higgs portal, Phys. Rev. D 111, 055029 (2025).
F.-Z. Chen, Q. Wen, and F. Xu, Correlating $B \to K^{(*)} ν \bar{ν}$ and flavor anomalies in SMEFT, Eur. Phys. J. C 84, 1012 (2024).
E. Gabrielli, L. Marzola, K. Müürsepp, and M. Raidal, Explaining the $B^{+} \to K^{+} ν \bar{ν}$ excess via a massless dark photon, Eur. Phys. J. C 84, 460 (2024).
B.-F. Hou, X.-Q. Li, M. Shen, Y.-D. Yang, and X.-B. Yuan, Deciphering the Belle II data on $B \to K ν \bar{ν}$ decay in the (dark) SMEFT with minimal flavour violation, J. High Energy Phys. 06 (2024) 172.
C.-H. Chen and C.-W. Chiang, Rare B and K decays in a scotogenic model, Phys. Rev. D 110, 075036 (2024).
X.-G. He, X.-D. Ma, M. A. Schmidt, G. Valencia, and R. R. Volkas, Scalar dark matter explanation of the excess in the Belle II $B^{+} \to K^{+} + invisible$ measurement, J. High Energy Phys. 07 (2024) 168.
P. D. Bolton, S. Fajfer, J. F. Kamenik, and M. Novoa-Brunet, Signatures of light new particles in $B \to K^{(*)} E_{miss}$ , Phys. Rev. D 110, 055001 (2024).
S. Rosauro-Alcaraz and L. P. S. Leal, Disentangling left and right-handed neutrino effects in $B \to K^{(*)} ν ν$ , Eur. Phys. J. C 84, 795 (2024).
J. F. Eguren, S. Klingel, E. Stamou, M. Tabet, and R. Ziegler, Flavor phenomenology of light dark vectors, J. High Energy Phys. 08 (2024) 111.
A. J. Buras, J. Harz, and M. A. Mojahed, Disentangling new physics in $K \to π ν \bar{ν}$ and $B \to K (K^{*}) ν \bar{ν}$ observables, J. High Energy Phys. 10 (2024) 087.
C. Hati, J. Leite, N. Nath, and J. W. F. Valle, The QCD axion, colour-mediated neutrino masses, and $B^{+} \to K^{+} + E_{miss}$ anomaly, Phys. Rev. D 111, 015038 (2025).
L. Allwicher, M. Bordone, G. Isidori, G. Piazza, and A. Stanzione, Probing third-generation new physics with $K \to π ν \bar{ν}$ and $B \to K^{(*)} ν \bar{ν}$ , Phys. Lett. B 861, 139295 (2025).
D. Bečirević, S. Fajfer, N. Košnik, and L. Pavičić, Right-handed interactions in puzzling $B$ -decays, Phys. Lett. B 861, 139285 (2025).
W. Altmannshofer and S. Roy, A joint explanation of the $B \to π K$ puzzle and the $B \to K ν \bar{ν}$ excess, Phys. Rev. D 111, 075029 (2025).
A. J. Buras and P. Stangl, On the interplay of constraints from $B_{s}$ , $D$ , and $K$ meson mixing in $Z^{'}$ models with implications for $b \to s ν \bar{ν}$ transitions, Eur. Phys. J. C 85, 519 (2025).
W. Altmannshofer, S. A. Gadam, and K. Toner, New strategies for new physics search with $Λ_{b} \to Λ ν \bar{ν}$ decays, Phys. Rev. D 111, 075005 (2025).
L. Calibbi, T. Li, L. Mukherjee, and M. A. Schmidt, Is dark matter the origin of the $B \to K ν \bar{ν}$ excess at Belle II?, Phys. Rev. D 112, 075020 (2025).
X.-G. He, X.-D. Ma, J. Tandean, and G. Valencia, $B \to K +$ invisible, dark matter, and $C P$ violation in hyperon decays, J. High Energy Phys. 07 (2025) 078.
P. D. Bolton, S. Fajfer, J. F. Kamenik, and M. Novoa-Brunet, Impact of new invisible particles on $B \to K^{(*)} E_{miss}$ observables, Phys. Rev. D 112, 035010 (2025).
C.-H. Chen, C.-W. Chiang, and L. M. G. de la Vega, Leptoquark-mediated Dirac neutrino mass and its impact on $B \to K ν \bar{ν}$ and $K \to π ν \bar{ν}$ decays, J. High Energy Phys. 09 (2025) 055.
T. M. Aliev, A. Elpe, L. Selbuz, and I. Turan, Explaining Belle data on $B \to K^{(*)} ν \bar{ν}$ decays via dark Z resonances, Phys. Rev. D 112, 015025 (2025).
K. Ding, Y. Li, X. Liu, Y. Liu, C.-T. Lu, and B. Zhu, Resonant ALP-portal dark matter annihilation as a solution to the $B^{\pm} \to K^{\pm} ν \bar{ν}$ excess, arXiv:2504.00383.
L. Di Luzio, M. Nardecchia, and C. Toni, Gauged $τ$ -lepton chiral currents and $B \to K^{(*)} E_{miss}$ , Phys. Rev. D 112, 055031 (2025).
A. Shaw, Belle II constraints on the non-minimal universal extra dimensional model, arXiv:2509.20027.
D. Das, D. Shameer, and R. Sain, $Λ_{b} \to Λ^{(*)} ν \bar{ν}$ decays and the recent Belle-II $B^{+} \to K^{+} ν \bar{ν}$ data, Phys. Rev. D 112, 013012 (2025).
J.-P. Lee, $Λ_{b} \to Λ^{(*)} ν \bar{ν}$ and $b \to s B$ decays, arXiv:2509.26370.
N. Das and R. Dutta, New physics analysis of $Λ_{b} \to (Λ^{*} (\to p K^{-}), Λ (\to p π)) (μ^{+} μ^{-}, ν \bar{ν})$ baryonic decays under SMEFT framework, Phys. Rev. D 108, 095051 (2023).
T. M. Aliev and M. Savci, Unparticle physics effects in $Λ_{b} \to Λ +$ missing energy processes, Phys. Lett. B 662, 165 (2008).
B. B. Sirvanli, Semileptonic $Λ_{b} \to Λ ν \bar{ν}$ decay in the leptophobic $Z^{'}$ model, Mod. Phys. Lett. A 23, 347 (2008).
C.-H. Chen and C. Q. Geng, Study of $Λ_{b} \to Λ ν \bar{ν}$ with polarized baryons, Phys. Rev. D 63, 054005 (2001).
Y. Amhis, M. Kenzie, M. Reboud, and A. R. Wiederhold, Prospects for searches of $b \to s ν \bar{ν}$ decays at FCC-ee, J. High Energy Phys. 01 (2024) 144.
G. Buchalla and A. J. Buras, QCD corrections to rare K and B decays for arbitrary top quark mass, Nucl. Phys. B400, 225 (1993).
M. Misiak and J. Urban, QCD corrections to FCNC decays mediated by Z penguins and W boxes, Phys. Lett. B 451, 161 (1999).
G. Buchalla and A. J. Buras, The rare decays $K \to π ν \bar{ν}$ , $B \to X ν \bar{ν}$ and $B \to l^{+} l^{-}$ : An update, Nucl. Phys. B548, 309 (1999).
J. Brod, M. Gorbahn, and E. Stamou, Two-loop electroweak corrections for the $K \to π ν \bar{ν}$ decays, Phys. Rev. D 83, 034030 (2011).
D. Bečirević, G. Piazza, and O. Sumensari, Revisiting $B \to K^{(*)} ν \bar{ν}$ decays in the standard model and beyond, Eur. Phys. J. C 83, 252 (2023).
T. Feldmann and M. W. Y. Yip, Form factors for $Λ_{b} \to Λ$ transitions in the soft-collinear effective theory, Phys. Rev. D 85, 014035 (2012).
W. Detmold and S. Meinel, $Λ_{b} \to Λ ℓ^{+} ℓ^{-}$ form factors, differential branching fraction, and angular observables from lattice QCD with relativistic $b$ quarks, Phys. Rev. D 93, 074501 (2016).
K. G. Chetyrkin, J. H. Kuhn, and M. Steinhauser, rundec: A Mathematica package for running and decoupling of the strong coupling and quark masses, Comput. Phys. Commun. 133, 43 (2000).
F. Herren and M. Steinhauser, Version 3 of RunDec and CRunDec, Comput. Phys. Commun. 224, 333 (2018).
Particle Data Group, Review of particle physics, Phys. Rev. D 110, 030001 (2024).
HPQCD Collaboration, $B \to K$ and $D \to K$ form factors from fully relativistic lattice QCD, Phys. Rev. D 107, 014510 (2023).
J. A. Bailey et al., $B \to K l^{+} l^{-}$ decay form factors from three-flavor lattice QCD, Phys. Rev. D 93, 025026 (2016).
HPQCD Collaboration, Rare decay $B \to K ℓ^{+} ℓ^{-}$ form factors from lattice QCD, Phys. Rev. D 88, 054509 (2013).
N. Gubernari, M. Reboud, D. van Dyk, and J. Virto, Dispersive analysis of $B \to K^{(*)}$ and $B_{s} \to ϕ$ form factors, J. High Energy Phys. 12 (2023) 153.
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).

Phys. Rev. D 112, 095007– Published 7 November, 2025

Vol. 112, Iss. 9 — 1 November 2025

Received 13 October 2025
Accepted 20 October 2025

DOI: https://doi.org/10.1103/zp29-r1l6

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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Influence of invisible light particles on $Λ_{b} \to Λ E_{miss}$

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Influence of invisible light particles on Λb→ΛEmiss

Abstract

Physics Subject Headings (PhySH)

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References (59)

Influence of invisible light particles on $Λ_{b} \to Λ E_{miss}$