{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"04e06c2111b33b6f7958e3f474578db4513dd410ccf48729c30db30056bb8ff9","created":"2026-10-03T07:18:07Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","bbe8d97ea817eaaa690cc2570dda16cc32c1e41c3503957a678054bd299643a3"],"salt":"077fc217446abfa015ff3b7b2d19587f5a01b14dd81989ec7112a49e9f00321d","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"nuc.emc-src.flavor-dependence","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"bbe8d97ea817eaaa690cc2570dda16cc32c1e41c3503957a678054bd299643a3","relation":"special_case"}],"plain":"In nuclei with more neutrons than protons, the modification could act differently on up and down quarks if it comes from proton-neutron pairs. This has never been measured separately.","posed_since":"","precise":"Determine $u_A(x)/u_N(x)$ and $d_A(x)/d_N(x)$ separately in 48Ca or 208Pb for $0.3 < x < 0.7$, using parity-violating DIS asymmetries (SoLID at JLab), 3H/3He mirror ratios, or W-boson production in proton-nucleus collisions. Answer: whether an isovector EMC effect is nonzero, and its magnitude.","problem_ref":null,"references":"","settled_by":"Parity-violating electron DIS on 48Ca at percent-level precision.","status_note":"","title":"Is the EMC effect different for up and down quarks?","topic_ref":"7a074c9c279467b77e19375da4dad17647254ffcdf3c39de667bd47e1e1c500e"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"b8811d4e5b472970b5bd7cec36b3c2f55669a9acf5b95532b8a93ab0afd332d1","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"4f3dc1afbf3e31a5443f63f78acb724b589df4ed5d68338081911f0a86e0f5dd","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"hxZ1p4yKm42TMLx0WfUdWdq4j7avKL6jc4bLW6LaLdWz8YQy3OprFbciS1pOFE3lOryaiczOWaCFjeZ8B1PCAA"},"schema":"pubphys.envelope/1"},"record_hash":"b8811d4e5b472970b5bd7cec36b3c2f55669a9acf5b95532b8a93ab0afd332d1","leaf_index":1741}