{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/the-constituent-counting-rule-and-omega","title":"The Constituent Counting Rule and Omega Photoproduction","arxiv_id":"2005.13067","date":"2020-05-26","proceeding":null,"authors":["Trevor Reed","Christopher Leon","Frank Vera","Lei Guo","Brian Raue"],"abstract":"The constituent counting ruling (CCR) has been found to hold for numerous hard, exclusive processes. It predicts the differential cross section at high energies and fixed $\\cos \\theta_{c.m.}$ should follow $\\frac{d \\sigma}{dt} \\sim \\frac{1}{s^{n-2}}$, where $n$ is the minimal number of constituents involved in the reaction. Here we provide an in-depth analysis of the reaction $\\gamma p \\rightarrow \\omega p$ at $\\theta_{c.m.}\\sim 90^\\circ$ using CLAS data with an energy range of $s = 5 - 8$ GeV$^2$, where the CCR has been shown to work in other reactions. We argue for a stringent method to select data to test the CCR and utilize a Taylor-series expansion to take advantage of data from nearby angle bins in our analysis. Na\\\"{i}vely, this reaction would have $n=9$ (or $n=10$ if the photon is in a $q\\bar{q}$ state) and we would expect a scaling of $\\sim s^{-7}$ ($s^{-8}$). Instead, a scaling of $s^{-(9.08 \\pm 0.11)}$ was observed. Explanations for this apparent failure of the na\\\"{i}ve CCR assumptions are examined.","url_abs":"https://arxiv.org/abs/2005.13067v2","url_pdf":"https://arxiv.org/pdf/2005.13067v2.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"the-constituent-counting-rule-and-omega","repo_url":"https://github.com/ChrisLeon84/MCMC-Bayesian-Estimate","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}