Inclusive weak decays of the J/ψ: single-charm decay and weak annihilation
Abstract
Conventional estimates of J/ψ weak decays, based on independent single-charm decays, suggest a branching fraction of order 10−8. Searches with samples of approximately 1010 J/ψ events have so far yielded upper limits on exclusive modes. We calculate the inclusive weak branching fraction using the optical theorem, including single-charm decay, charged- and neutral-current annihilation, and their interference. The heavy-quark expansion identifies the leading pair-annihilation structure and motivates vacuum saturation for the leading color-singlet component. With tree-level hard kernels and leading-logarithmic Wilson coefficients at μ0=MJ/ψ, we obtain Bweak=(7.96+3.43−0.43±1.24)×10−8. The contribution mediated by the W boson alone, i.e. single-charm decays and W-exchange annihilation without the W-Z interference, has a branching fraction of (2.37+1.64−0.42±0.13)×10−8. For the flavor sectors (ΔC,|ΔS|)=(0,1) and |ΔC|=1, the branching fractions are (4.97+16.44−4.97±0.99)×10−10 and (1.86+0.20−0.06±0.02)×10−8, respectively, including charge-conjugate channels. The first uncertainty estimates missing perturbative corrections through scale variation over 1 GeV≤μ≤3MJ/ψ. The second is a hadronic uncertainty, obtained by jointly varying each vacuum-saturation and kinetic/chromomagnetic input within relative ranges of ΛQCD/mc≃20%. Pair annihilation dominates, with a substantial neutral-current contribution and scale-sensitive W-Z interference.
Related
- New measurements of B+c decays into single charm final states
- Inclusive productions of J/ψ+ηc in e+e− annihilation at Belle
- Search for rare charm decays at BESIII
- Precise Measurement of the Inclusive Cross Sections of Open-Charm Mesons at Energies from 3.80 to 4.95 GeV
- Two-body strong decays of the Pcs(4338) as a hidden-charm pentaquark state via the QCD sum rules
BibTeX
@misc{li2026inclusive,
title = {{Inclusive weak decays of the $J/ψ$: single-charm decay and weak annihilation}},
author = {Lan-Bin Li and Chia-Wei Liu and Peng-Yuan Zheng},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.30649},
eprint = {2610.30649},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.30649},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Inclusive weak decays of the J/ψ: single-charm decay and weak annihilation
AU - Lan-Bin Li
AU - Chia-Wei Liu
AU - Peng-Yuan Zheng
PY - 2026
DA - 2026/10/22
PB - arXiv
DO - 10.48550/arxiv.2610.30649
UR - https://arxiv.org/abs/2610.30649
AB - Conventional estimates of J/ψ weak decays, based on independent single-charm decays, suggest a branching fraction of order 10^−8. Searches with samples of approximately 10^10 J/ψ events have so far yielded upper limits on exclusive modes. We calculate the inclusive weak branching fraction using the optical theorem, including single-charm decay, charged- and neutral-current annihilation, and their interference. The heavy-quark expansion identifies the leading pair-annihilation structure and motivates vacuum saturation for the leading color-singlet component. With tree-level hard kernels and leading-logarithmic Wilson coefficients at μ_0=M_J/ψ, we obtain B_weak=(7.96^+3.43_−0.43±1.24)×10^−8. The contribution mediated by the W boson alone, i.e. single-charm decays and W-exchange annihilation without the W-Z interference, has a branching fraction of (2.37^+1.64_−0.42±0.13)×10^−8. For the flavor sectors (ΔC,|ΔS|)=(0,1) and |ΔC|=1, the branching fractions are (4.97^+16.44_−4.97±0.99)×10^−10 and (1.86^+0.20_−0.06±0.02)×10^−8, respectively, including charge-conjugate channels. The first uncertainty estimates missing perturbative corrections through scale variation over 1 GeV≤μ≤3M_J/ψ. The second is a hadronic uncertainty, obtained by jointly varying each vacuum-saturation and kinetic/chromomagnetic input within relative ranges of Λ_QCD/m_c≃20%. Pair annihilation dominates, with a substantial neutral-current contribution and scale-sensitive W-Z interference.
ER -