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Non-Forward OPE Kernel versus Scalar Form Factor in Near-Threshold J/ψ Photoproduction
Abstract
Near-threshold J/ψ photoproduction has been used to infer scalar gluonic structure from integrated cross-section data. We test whether such an inference is stable against the assumed non-forward continuation of the OPE kernel. With an exponential diffractive slope fixed, the threshold fit favors an additional scalar GS(t)-like contribution. However, the residuals show a systematic W-dependent trend. When either the effective slope or the kernel shape is replaced by a physically motivated form-factor continuation, the trend disappears and the fitted scalar coefficient is driven to zero. Thus integrated σ(W) data cannot determine the non-forward OPE kernel or isolate a scalar GS(t) contribution. Differential dσ/dt data are required.
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BibTeX
@misc{syamtomov2026nonforward,
title = {{Non-Forward OPE Kernel versus Scalar Form Factor in Near-Threshold $J/ψ$ Photoproduction}},
author = {A. I. Syamtomov},
howpublished = {arXiv},
year = {2026},
month = jun,
doi = {10.48550/arxiv.2605.10803},
eprint = {2605.10803},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.10803},
}
RIS
TY - UNPB
TI - Non-Forward OPE Kernel versus Scalar Form Factor in Near-Threshold J/ψ Photoproduction
AU - A. I. Syamtomov
PY - 2026
DA - 2026/06/10
PB - arXiv
DO - 10.48550/arxiv.2605.10803
UR - https://arxiv.org/abs/2605.10803
AB - Near-threshold J/ψ photoproduction has been used to infer scalar gluonic structure from integrated cross-section data. We test whether such an inference is stable against the assumed non-forward continuation of the OPE kernel. With an exponential diffractive slope fixed, the threshold fit favors an additional scalar G_S(t)-like contribution. However, the residuals show a systematic W-dependent trend. When either the effective slope or the kernel shape is replaced by a physically motivated form-factor continuation, the trend disappears and the fitted scalar coefficient is driven to zero. Thus integrated σ(W) data cannot determine the non-forward OPE kernel or isolate a scalar G_S(t) contribution. Differential dσ/dt data are required.
ER -