Reassessing the X(2370) in J/ψ→γKS0KS0π0 beyond the one-dimensional mass projections
Abstract
The BESIII Collaboration recently extracted the properties of the X(2370) from a fit to the one-dimensional KS0KS0π0 invariant-mass spectrum in J/ψ→γKS0KS0π0. The intermediate two-body structures visible in the mass correlations, including the K0*(1430) bands, require a coherent treatment of cross-channel interference when interpreting the enhancement near 2.3 GeV. We reassess the need for an additional X(2370) contribution by fitting the published data using an effective coupled-channel framework with an approximate detection efficiency depending on the three-body invariant mass. The three-body parent amplitude is parameterized using a K-matrix that describes scattering among several quasi-two-body channels. The seven- and eight-bare-state models give similar mass distributions. Adding the eighth bare state lowers the Poisson deviance by 1.22% and produces an additional pole at E=(2419−i152) MeV, substantially broader than the X(2370) mass-width reference. This pole is model-dependent, and its identification with the X(2370) is not clear. The present analysis does not establish the need for an additional X(2370) contribution in J/ψ→γKS0KS0π0, thereby weakening the flavor-singlet argument based on the suppression of K*K̅ relative to the total KK̅π contribution. A more comprehensive experimental amplitude analysis, incorporating coherent interference, mass and angular correlations, and detector effects across related decay channels, is needed to establish the role and decay properties of the X(2370).
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BibTeX
@misc{dong2026reassessing,
title = {{Reassessing the $X(2370)$ in $J/ψ\toγK_S^0K_S^0π^0$ beyond the one-dimensional mass projections}},
author = {Xiang-Kun Dong and Teng Ji and Meike Küßner and Ulf-G. Meißner},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.11937},
eprint = {2610.11937},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.11937},
}
RIS
TY - UNPB
TI - Reassessing the X(2370) in J/ψ→γK_S^0K_S^0π^0 beyond the one-dimensional mass projections
AU - Xiang-Kun Dong
AU - Teng Ji
AU - Meike Küßner
AU - Ulf-G. Meißner
PY - 2026
DA - 2026/10/16
PB - arXiv
DO - 10.48550/arxiv.2610.11937
UR - https://arxiv.org/abs/2610.11937
AB - The BESIII Collaboration recently extracted the properties of the X(2370) from a fit to the one-dimensional K_S^0K_S^0π^0 invariant-mass spectrum in J/ψ→γK_S^0K_S^0π^0. The intermediate two-body structures visible in the mass correlations, including the K_0^*(1430) bands, require a coherent treatment of cross-channel interference when interpreting the enhancement near 2.3 GeV. We reassess the need for an additional X(2370) contribution by fitting the published data using an effective coupled-channel framework with an approximate detection efficiency depending on the three-body invariant mass. The three-body parent amplitude is parameterized using a K-matrix that describes scattering among several quasi-two-body channels. The seven- and eight-bare-state models give similar mass distributions. Adding the eighth bare state lowers the Poisson deviance by 1.22% and produces an additional pole at E=(2419−i152) MeV, substantially broader than the X(2370) mass-width reference. This pole is model-dependent, and its identification with the X(2370) is not clear. The present analysis does not establish the need for an additional X(2370) contribution in J/ψ→γK_S^0K_S^0π^0, thereby weakening the flavor-singlet argument based on the suppression of K^*K̅ relative to the total KK̅π contribution. A more comprehensive experimental amplitude analysis, incorporating coherent interference, mass and angular correlations, and detector effects across related decay channels, is needed to establish the role and decay properties of the X(2370).
ER -