{"schema":"pubphys.bundle/1","record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"6a7e4beb7b7c4d57eced608cdde3afbbfdfa592d6dad09ebfe223e22948a1e75","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","d32c3b2077e2ce6a0db88d006adece91cf6fed11603e69ad3b1fc261cca48df4"],"salt":"eee32086c9808a476a81c77d9f65f8d02e6a9b2cbbd1ccab4ba90f4a36767100","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"amo.lorentz-cpt.antihydrogen-1s2s","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"Antihydrogen (an antiproton bound to a positron) should have exactly the same energy levels as hydrogen if matter and antimatter mirror each other perfectly. The main ultraviolet line has been compared to a few parts in $10^{12}$; hydrogen itself is known about a thousand times better.","posed_since":"","precise":"ALPHA measured the antihydrogen $1\\mathrm{S}-2\\mathrm{S}$ two-photon frequency in agreement with hydrogen at about $2 \\times 10^{-12}$ relative precision (2018). Determine whether nu_1S2S(Hbar) - nu_1S2S(H) is nonzero at the $10^{-15}$ level, approaching the hydrogen precision of about 4e-15.","problem_ref":"d32c3b2077e2ce6a0db88d006adece91cf6fed11603e69ad3b1fc261cca48df4","references":"","settled_by":"Antihydrogen 1S-2S spectroscopy with laser-cooled, magnetically trapped atoms reaching sub-kHz resolution and $10^{-15}$ accuracy.","status_note":"ALPHA demonstrated laser cooling of antihydrogen in 2021, a prerequisite for the next precision step.","title":"Does antihydrogen 1S-2S match hydrogen at $10^{-15}$?","topic_ref":null},"content_withheld":"false","files":[],"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"738e0edf2ab44076d72567c71692b71bd8adeae1031d1e2b4d1b8be9ae7b90bd","schema":"pubphys.attested/1"},"id_token":null,"id_token_withheld":"false","envelope":{"attested_hash":"0bfe43d5ea17c828800f5010a4a23dd802e3296476bc06d526d7c946745b794b","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"loAyT98kMFUsueTL3QJUjCasrwhiKfp2Wu3iwQnDfrIWl4zC69K1vaUCK5h-jmlmQi7vZYjlNFTqwLXkNANyBQ"},"schema":"pubphys.envelope/1"},"ots":{"attested":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEIC_5D1eoXyCiAD1AQpKI92ALjKWR2vAbVJtfJRnRbeUvxIAvyogha-KOtB8Xo-JXgJfjlAlbyzUxbFwzQSz44Uy_JCPEgkLLhhOtaflcZsQVn7ZB7P_mYZnxxCUQ0yGohMXjxtzkI8CDrUN9_HB8AeWm3i8CUsdavBbJ9CW7xF44YwvfqPzvDiQjxII_dVAGRHTC85jQ-EGEFevQrxChS-LV_X-xerhAffFnzCPAg3DLrPJPucJjxjrCZVt6OTtRV60bH1y6L9pPcDy_4rEwI8SAqedefj2z4CJuuoziyY7PkDd5FsffqaxBH_FLKU9qq-AjwIFKyw0XNzLkprI-i8ECJNT2-eN8CobQHSKw90_ITiI3sCPEgtFEK0VubfP67YUyPihYaN9dTg9fCnso7LYYm40h86RMI8CBUfn8vND_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"],"envelope":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEISTwyQEysCWkVHye4WNzz5wE42tfISMdxXMeYLrzg_2nwIEk_Ysm8IgwngHHJGzv700_Qn5pmRMyj5CNQvWsJh_L3CPAg4Y3O33Ig2T4vZ7b8ymuxmwvSFnZxcOxIKM2ioo9MFs8I8SCSMKrZWIFIWTq5fI-nRtBYOJDLj77ZtcgC6-wnEZWTUwjwIPu9oRD8TB4qQt5sD12fsBvTBzfv1Qx9ITLf0OboSKP3CPAgZ4dFGNIhYNlMOS0taNSFkf3h6iTcP4NxV_e1gLYiFW8I8CCIYzcOtT0KU7CwKxf-qN6HpRjmYBA6v17HvIB0XqhiiwjxIBhB27X2sRsQbro8Joy-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":"2238","tree_size":"3804","proof":["5622f8b44a3b65163f2994332ccd5c6f868a940b1f78f520eebcad0d8e121c13","87781c5522255ba13f5fc9eaedd1bd68bbf3e4e52a08dbd6784b47786aeb4375","74b987191a5388b7c36109362749ee644a4cdb25f91354066ff89ba5ca493035","6d99aa3e5ef5b20b6cef8d59406b46001e5de62838ba31ebc3c30ac05f9c2310","809fd47e060a290f03fc81da0538cbf22c45dca360d7653bb7be2dc73e3f75ff","161d8bf433ae645616c7c6a125497d03efce949a5dc7960e323b3e24ca5621f3","6a6dd27141672b28efa1ee62891bc3591ef1954d1d4256adbabec756be6e0a64","9761eb0f4689d6e5f28934059787de8a9f8da3f799c91405afdf99769db5c00d","9f197ad4a050ba9a768c42080a12af180f8a85b30776c547c433648f943b3824","453fe2db8b5276d732edac85634e8be036b4709a91a2584f32a4b9edcc8ca9de","325287f5a43e4f3ad4072ec4bd53d43c50c1393021a056122e9cb0fad83b868f","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\n64ea2a9230d4a3e3765a8eb0f0980849a601c216abed8f1daa051a7950ae20d5\n2238\n2026-10-15T23:43:57Z\n2026-10-16T01:43:57Z\n\n— pubphys.com/log/v1 JFPwILESs1H3jRiprawWVrt3ph4iDVBJdFi0fpqkp8y6KNCecZynn22X+PMXX6VbiK05kocMQIcL+SrmKxTZvsoljw8=\n"},"orcid_key_evidence":[],"attesting":null}