{"schema":"pubphys.bundle/1","record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"cc1bae0dfd9a2aaf88d89a25869c6fb48e38635754d5e45b96fbc34883885770","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["65cad78542e44a39679ea3d379ed3054dc7d8a4646c2b5074fca3f9f2164231f","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"f1b36d0b40db6e81909acde89093e3c75064a8bed1259827563db4e2a40742e6","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"nuc.proton-structure.gluon-helicity","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"Gluons, the particles that bind quarks, can carry spin aligned with the proton's. Collider data show a positive contribution from medium-momentum gluons, but the part from very low-momentum gluons is unknown.","posed_since":"","precise":"Determine $\\Delta G(\\mu^{2})=\\int_{0}^{1}\\mathrm{d}x\\ \\Delta g(x,\\mu^{2})$ at $\\mu^{2}=10\\ \\mathrm{GeV}^{2}$, where $\\Delta g$ is the gluon helicity distribution and x the gluon momentum fraction. RHIC polarized pp data give $\\int_{0.05}^{0.2}\\Delta g\\ \\mathrm{d}x=0.20\\ (+0.06,-0.07)$ (de Florian et al., 2014) under a positivity assumption; the open part is $x<0.01$, where no data exist, together with the residual dependence of the sign on high-x and $\\mathrm{SU}(3)$ assumptions. Answer: $\\Delta G$ with total uncertainty below 0.05.","problem_ref":"65cad78542e44a39679ea3d379ed3054dc7d8a4646c2b5074fca3f9f2164231f","references":"","settled_by":"Scaling violations of the polarized structure function $g_{1}$ measured at the EIC over $10^{-4} < x < 0.5$, combined in a global fit with RHIC data.","status_note":"Fits without positivity admitted negative $\\Delta g$ (JAM, 2022); lattice Ioffe-time data could not fix the sign (Karpie et al., 2023), but adding high-x polarized DIS data disfavored the negative solution (Hunt-Smith et al., 2024); the $x < 0.01$ contribution remained unmeasured as of 2026.","title":"Total gluon spin contribution $\\Delta G$ to the proton spin","topic_ref":null},"content_withheld":"false","files":[],"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"5f16c95ef7800280d40ca22a682434ad405547ab3988678e4025a65c74f108d9","schema":"pubphys.attested/1"},"id_token":null,"id_token_withheld":"false","envelope":{"attested_hash":"b651da328c733b3da068a87fe262f5e15b2b561bbb567f9b5963f561717317cd","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"PMrfoYb6nPQe0HbE3RF1nH0HHkDEJ4ZRx2vlZxcf4iY9k4xHVau8naTSSEDRuV5Z6VUs9p3B8PvNOa1xYcx2Cg"},"schema":"pubphys.envelope/1"},"ots":{"attested":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEItlHaMoxzOz2gaKh_4mL14VsrVhu7Vn-bWWP1YXFzF83xILZO8exxbi2imKtQAmo7OPBN_oD6wmQddZzYZbNGZpCiCPEgJveilPxAn4hAZFq16Ao-ivRWa91odEIW0p21YuUoQc8I8SCN7c8inHCUQf81XX2Is9fCWRBIU3BaSnnKu8dVyKMcIwjwIClO_fLKhu68CyC1cXLoO1jPD5SZso1fsPYFaaOO-8WWCPEg_c-UJMCql1K5vjusCC4VbVJns-NHj3-kgKZ7MfUAB1QI8CDuxny7d7Cv4pSdyJIKf1c5GX5jDtId83esEJK0hEHeFQjxIDwyhdMMcC9HUXvmnOqr-4hz0bthwNRePVXecoiwxma1CPAgsToia8UFTWcgAGCYERTkLASNsxtWD-53uc5ktQ4BIIgI8SDArwsGYVuomKH_DJiJGziPwECn7skqn20TGM58Ezco0wjwIIgwugvlgSNOmTWMhquqetKjeLf0x7d1a1MH4KU52JbFCPAg3mczMYDKOd7Nhf3ojA9ZvuTsN66Y1NnyYTp9j8GKQNwI8SCvAiiN-Hrv7IEejd8wdUihoozu5KOvpoBFJ0vg3UnGAQj_8Ajn9YmozHwo9QjwEJ46aM9ZDv3TdtqV3ZbRsNgI8SBOF8pILGf1kodr5MKmQs6Cd93joraGn3g6UPt_-kewPwjwIOG-gmM7bd_eR4AiDMNfluS3xvr7vicLR-sCBr5qtG2cCPAgrVNFrCoeQcCxhlmnE0BzHgR8HQpZAlfqzDDFzfWb8GUI8QRq0WWT8AjZJ2cF_c7k8ACD3-MNLvkMjiwraHR0cHM6Ly9ib2IuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZ_AI9ZMS1zxd7IEI8BDd00WgJZ0RncsC1Fyai_4aCPEgvxMFrnu7F05IW5INiraQ3OVEYMjNx6JfBxw1Q4jPLi4I8QRq0WWS8Ag2zxPAtI5JsP8Ag9_jDS75DI4uLWh0dHBzOi8vYWxpY2UuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZwjxIHAnv4KFFf4uiYEFJvLxiMxSyz8VowJP4roTfDD9h7bICPAgj5tgvbNF7mxSP4jGGE66ezUFRLnI4g1VTkvuV4VtCPAI8CCxlc1HuKORuHgn7DYIYcDhc4oo99OkTWBEvddBypoa7AjwIFcjjaF8kDNDYCZGaNISlRjvX-I7in-QNwsr4JYQbFJvCPAgnl0k4gs7LuY5i1umiHO-J7My3uBThLJUWQoY9LdVSrQI8SA6-Ft11_K_GqMNWYhkVsVqCFvXSYbp4S8JoLsLBnUzvgjxIBC8_mAE7JBP35SNxDBcG7joLJwURpMxdV2vSO64_jEOCPEge04Coj1xSi7CE8UwqiBGNhPyZ5QdD_YZwn-heSdObU4I8SBgdDSgr3VUx1j8m_pK7-OzMwwFgXeLy43ujffCv-hf5AjwIMl-PnAt4xjoBEVU4-nkyN0NKRa9AvX4kEMfllFyIJS9CPFZAQAAAAHz4rV-uwQFg02bVnEMUFgpIdGKjM4tWuID1kTVnrjisAAAAAAA_v___wJURAIAAAAAABYAFBFys2oc0-U-bYrC3VulGLzND5fbAAAAAAAAAAAiaiDwBHLTDgAICPEgMJIBYi46xOIuFDwzJ9nOx14ngW5HbglUf65ORpkoIYcICPAgHgGWEGCDHWgscwT92NOoJ7s-ezbPkyiWr2RnYZDC_dwICPAgtffMyyLu-MscJsDc0dzwGspwSrrmvVAnMNgsgWhHClgICPAgMUl1OfBDUwhp5VZjHwVA0nuz1F5HZTUJCHAnM1L1F3MICPAgStK7UWpnrUueV5EaE7uE0y6BLMp6EANmrbhrTqEBZu8ICPAg5LVW7IHtUL5mNOvPx1hOTfLMmqlQ7t9EFW-KDtrISIQICPAgABgXZ6upFU8qiDQKFtQFpqkjKwl0PsxM4JUjVLlDKbkICPAgEwb96FiOhjlbwI8GFZQ4a5GXwxs4bUdqVOMKrtBWV30ICPEgqBg-wp0c8CAPV9k6J7wIa9_GtQfpWmhpE1zqFZyi2pQICPAg2pZLTVPGJbriiz0UhMytYDVYAXOgQnWDcrMOewK9O8cICPEgxm3QwzbvT4siJzubQGnST67bWv-exYwSPP1KDi7CaUwICPEgm6udUudfjUaM0gUFTylKGDMypj7ptMTG0zmxd_T5yTcICPAgMpOInkjFCVp1pOZhfZnyPAl8hdWGmHzQcrGLgLwSKLgICAAFiJYNc9cZAQPzpjs"],"envelope":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEIB4RZ1t45OWRRzC1uKTZMxBTIbWEo3CAbWt9ZgbUYTd7xIAd9Db7wSH_O4x0Mx3GDfrUz_mPOZAO93HrwC_5mQdRxCPAgqNyvQ7e_RQu1fyotKCoHbKzxyE8MqnktcBFfsyNKm54I8SAiMnPicqcpiJNENfzTnYX2mQn7KYsgFeIiNYIifRk0oAjwIDiN7oQPJADzEiH2Q7xgfpdedr5aWP4MSA9fcLHNCtFPCPAgkwadM6BAw1xRBiIR9d3vo3VYjWl_tmZ_KgPHVmyGPqII8SAGF-wssJHeAYpgkdXwnlZoN9h_dO_NOeG25kUgdNHXnAjxIPItmuw3TTivimPtAwORvieSorUfbHVApv0JzkO9yahtCPAghRlAhJmWc0qdN-Mo674D6_tnilkvPnw8TGule_yDRm0I8CBUfn8vND_FHy1q8eURvKLesQojCPxZvV5RtrwTxl9iVwjwIKD8mGRUgbk2Dt1xG-4OxMpCuw1ya5UEUQXsqASURGCtCPAgkPXX-naXR0fRIdS-sEDlzYmtMvSCNH42ESUF0QXb6NUI8CDQo_sIWZiWXaTGRSQBLmU-lHJKskYKqsjO1r02DhB8LAj_8Ajn9YmozHwo9QjwEJ46aM9ZDv3TdtqV3ZbRsNgI8SBOF8pILGf1kodr5MKmQs6Cd93joraGn3g6UPt_-kewPwjwIOG-gmM7bd_eR4AiDMNfluS3xvr7vicLR-sCBr5qtG2cCPAgrVNFrCoeQcCxhlmnE0BzHgR8HQpZAlfqzDDFzfWb8GUI8QRq0WWT8AjZJ2cF_c7k8ACD3-MNLvkMjiwraHR0cHM6Ly9ib2IuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZ_AI9ZMS1zxd7IEI8BDd00WgJZ0RncsC1Fyai_4aCPEgvxMFrnu7F05IW5INiraQ3OVEYMjNx6JfBxw1Q4jPLi4I8QRq0WWS8Ag2zxPAtI5JsP8Ag9_jDS75DI4uLWh0dHBzOi8vYWxpY2UuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZwjxIHAnv4KFFf4uiYEFJvLxiMxSyz8VowJP4roTfDD9h7bICPAgj5tgvbNF7mxSP4jGGE66ezUFRLnI4g1VTkvuV4VtCPAI8CCxlc1HuKORuHgn7DYIYcDhc4oo99OkTWBEvddBypoa7AjwIFcjjaF8kDNDYCZGaNISlRjvX-I7in-QNwsr4JYQbFJvCPAgnl0k4gs7LuY5i1umiHO-J7My3uBThLJUWQoY9LdVSrQI8SA6-Ft11_K_GqMNWYhkVsVqCFvXSYbp4S8JoLsLBnUzvgjxIBC8_mAE7JBP35SNxDBcG7joLJwURpMxdV2vSO64_jEOCPEge04Coj1xSi7CE8UwqiBGNhPyZ5QdD_YZwn-heSdObU4I8SBgdDSgr3VUx1j8m_pK7-OzMwwFgXeLy43ujffCv-hf5AjwIMl-PnAt4xjoBEVU4-nkyN0NKRa9AvX4kEMfllFyIJS9CPFZAQAAAAHz4rV-uwQFg02bVnEMUFgpIdGKjM4tWuID1kTVnrjisAAAAAAA_v___wJURAIAAAAAABYAFBFys2oc0-U-bYrC3VulGLzND5fbAAAAAAAAAAAiaiDwBHLTDgAICPEgMJIBYi46xOIuFDwzJ9nOx14ngW5HbglUf65ORpkoIYcICPAgHgGWEGCDHWgscwT92NOoJ7s-ezbPkyiWr2RnYZDC_dwICPAgtffMyyLu-MscJsDc0dzwGspwSrrmvVAnMNgsgWhHClgICPAgMUl1OfBDUwhp5VZjHwVA0nuz1F5HZTUJCHAnM1L1F3MICPAgStK7UWpnrUueV5EaE7uE0y6BLMp6EANmrbhrTqEBZu8ICPAg5LVW7IHtUL5mNOvPx1hOTfLMmqlQ7t9EFW-KDtrISIQICPAgABgXZ6upFU8qiDQKFtQFpqkjKwl0PsxM4JUjVLlDKbkICPAgEwb96FiOhjlbwI8GFZQ4a5GXwxs4bUdqVOMKrtBWV30ICPEgqBg-wp0c8CAPV9k6J7wIa9_GtQfpWmhpE1zqFZyi2pQICPAg2pZLTVPGJbriiz0UhMytYDVYAXOgQnWDcrMOewK9O8cICPEgxm3QwzbvT4siJzubQGnST67bWv-exYwSPP1KDi7CaUwICPEgm6udUudfjUaM0gUFTylKGDMypj7ptMTG0zmxd_T5yTcICPAgMpOInkjFCVp1pOZhfZnyPAl8hdWGmHzQcrGLgLwSKLgICAAFiJYNc9cZAQPzpjs"]},"log":{"leaf_index":"3522","tree_size":"3804","proof":["6735e1604bc07d033ba92e4281a9c84c183587e59e1f6692ba4e5851d000f51e","a6a27546e950566b4bf236331b42197a3d552d9b02d6dc7225645bca97b5c6be","9214ba15e40fe0cff3b141a8284d9be07e4d96d58688c322bea305a92e03e2c6","fcf170609c083807550afa922a5574e7ced05479aefab41d9e52e9edecc510ab","9a17c88baad4ff4bceccbd097f1dbfd897ee59d9c7a403c5d9738e367fa19c70","68b9b21c71345d7a61159cb26c0f41da5833a037b1a75d1dcab7903dd3db95cc","266c6a520f7af5a577207d98d84af6d8d9ce15ca8b2ab64aa8d6617192db65df","32c308752f9217b1c4a86dd18bd7c428e4bf0819f03bcecd3c244aeb14e5c028","5bc8f1bbb7a36ffa2afc301ec767424419006f77d79dfc7ac3adb0dab9eb36e8","98b5a14b42b3a202b6ef825f66833fa505601404c4c0f14575f3ec922607a858","af34d80d0065c0ab502282775e865492e2cb49c9493f4594d63ba5577922854a","3c578dccc15502c5f3efe228cadc99fee76ab536ed01f66b14d316fdcc157429"],"checkpoint":"pubphys.com/log/v1\n3804\nAK6t4qgu96+M9wScTrIlsJ10d/zhKVEtYguyM3aeJvo=\n\n— pubphys.com/log/v1 JFPwIPP8EtoxgcsQg7V7CwIdL4UKPqJtpv+eB8sFNJjyQHIdyA1VabmBsPyLqq2bLxJPn57rA6fQi8y0QDDjRXHvlQg=\n","promise":"pubphys.com/log/v1 promise\nabb58f77052fdfbc100ccd129eaac5e974143b40b433e26b505002a426dc0a1b\n3522\n2026-10-15T23:43:57Z\n2026-10-16T01:43:57Z\n\n— pubphys.com/log/v1 JFPwIBWzeerdKroUz7lD2yq9qY8J17QTJHuhTf86lJja9LO2LscbomDxL8cyCE1QY4yH9JLJT7gvzmcoGmuqt9RVOgs=\n"},"orcid_key_evidence":[],"attesting":null}