{"schema":"pubphys.bundle/1","record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"cbe94b08dc9d8db0e9675aec4b1bd84ccfdba175d6a379eb93cdc84a11a565be","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["2b14938296c8ad1e49b251b2043ee7e420f8aee7ccd506042537a27815ad01d0","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"7eddc6c61852724501d058ad349c050ab65a98e665d6de20daaba0213c34abab","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":["ai:gpt-5.5"],"external_id":"hep.strong-cp.qcd-axion-existence","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"The axion would be a very light, very weakly interacting particle that removes the strong CP puzzle. Detectors search for it turning into a photon inside strong magnets.","posed_since":"1978","precise":"Determine whether a pseudoscalar a with $m_a \\sim 5.7\\ \\mathrm{micro-eV}\\ (10^{12}\\ \\mathrm{GeV}/f_a)$ and photon coupling $g_{agamma}$ inside the QCD axion band (KSVZ to DFSZ and beyond) exists, for $f_a\\ \\text{between}\\ \\sim 10^{8}\\ \\text{and}\\ \\sim 10^{17}\\ \\mathrm{GeV}$. An answer is a detection with $m_a$ and $g_{agamma}$ consistent with the QCD mass-decay constant relation, or exclusion of the band over the full range.","problem_ref":"2b14938296c8ad1e49b251b2043ee7e420f8aee7ccd506042537a27815ad01d0","references":"","settled_by":"Haloscope, helioscope (IAXO) and nuclear-coupling (CASPEr-type) searches covering the QCD axion band across micro-eV to meV masses.","status_note":"Haloscopes reach DFSZ sensitivity only in narrow windows of a few micro-eV as of 2025.","title":"Does the QCD axion exist?","topic_ref":null},"content_withheld":"false","files":[],"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"da79a19b082e330cd4029507e9fa93d4b18ef5ca9173ec54ce2ef153cd9f8c46","schema":"pubphys.attested/1"},"id_token":null,"id_token_withheld":"false","envelope":{"attested_hash":"485d0b5b5ca77680052da4e18bdd4893303b8c4e12dc1a44291f5038a17143ed","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"OlHvW6ffbaHxgKyVn9c1Sbkc-Mu06dfKE1vQhjNSsHQmIpuAYC2P32Im0sV9D1ohwwG8WTpe_4E0YCJPjbyqCA"},"schema":"pubphys.envelope/1"},"ots":{"attested":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEISF0LW1yndoAFLaThi91IkzA7jE4S3BpEKR9QOKFxQ-3xIEgx0GPG4BQf6f-m2t7caVMEnZAQHRnTd9_t7tKlBZOuCPEgHJpRXa8cw3UYMjqSywnzKJDlq5nn0VauDpXfBJtcjXII8CCtGJCoF1sgNaUYgR30JljLlWrzpDZBOcX6djpnHcb-CAjxIE1oRRh8-iwNOXEbSLaXVX5ad0LOQlAnIsfMCqOIJ63SCPEgMX8oV34h_j_aI9XVqOqsHoldySGXyV3WuqszHJhVrpII8SCxSIzs5Bz2-aA0hohgWVe-Jl5Es-3tSXoAu69KEXg2YgjwIIty2HwK5vrs2CMdyGCJIg9c3gHEb2VgCePnDOqzEY_GCPEgY6scDRpMTELRyAdQzoM_M72JG6gtvT5rKuV0H9Htq4AI8SDYW1nvfhAbf15fxYweLGiGtYK21xyRv_zJHX5DdVcU4wjxIJdQdDsL3v2lA7qZb8kMJtOgaTQmbgchdPcS5lYJqDLnCPAgkPXX-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"],"envelope":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEITHPLRGVd8eoWViJ_vcxT4e55BcNRIUWhXoRhFT3TNGPxIExNnrLkn47tTHVcDgHUU2sKp2ec9YSR-hlQ-RhCuIr5CPEg6MwcElOmN2cY7l_9gwO1mYOzbF-irwanzDrnqtc0FeYI8SB8fOeNqeW82DEE0UVWiRjlQ56yGI9H697r_HLYzDJuVgjwIL7SeZMzPQbU1gEnnzYYE2wiox1JYgZ7CkAmwLRe0B4ICPAgBB59Y-zGAfQ_1H-Zy9LSTCynI71mUGiu6XnQoDefy3EI8SBMtrWk8G8drtYgPSQAVqEJtzVHOx3Zy4Kn4m6mKJXP6AjxIBhB27X2sRsQbro8Joy-wdFNSVpVeMYyKR4AYna50JaDCPEgY6scDRpMTELRyAdQzoM_M72JG6gtvT5rKuV0H9Htq4AI8SDYW1nvfhAbf15fxYweLGiGtYK21xyRv_zJHX5DdVcU4wjxIJdQdDsL3v2lA7qZb8kMJtOgaTQmbgchdPcS5lYJqDLnCPAgkPXX-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":"3386","tree_size":"3804","proof":["ee6a8021854a1eb122873f65dc7ddcd210e4bcf229211a557123cf0c2c4d6781","ab95256613d5d755223cd89089e4ffe784ea508792b2ce3523f26ac1197631ed","3e6a53751e71d9d8a196e1ff2d79de187af6f362c8170f4f2829de6d4006c9d2","c0ffe14da7bbd8d033e4ec2a0da3a96c768bd000120c0fcd009ab0e95a5dc9a7","049c4dfb513c95bde476ca79e70e03d5f1eae3ad96259d1c81203b12c2a1aa0f","7487d3e803c2fe812f4eb58507f8e584230f4f927299049efc01e3a7a92d01b6","f53e55cbf0c3a29497278a68db662e4165ddf338dc5ab74121e2097cae8d3b55","f543c2acee32c00eed64ca6a002c4cdf20cd84f300a60f431863f4556659c7bc","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\ne4b7d0a3829e464b55b287ee40d235a5a58a27d42203fd701927908b81003f0d\n3386\n2026-10-15T23:43:57Z\n2026-10-16T01:43:57Z\n\n— pubphys.com/log/v1 JFPwIJpeYcXGawVxJTI54h9UBAj9w++CoN77iLfZTFkqcXOHy404LflCth2NxR0DVafpIKjSGuUYUInsYSFyVXaREwg=\n"},"orcid_key_evidence":[],"attesting":null}