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Title: Is the EMC effect different for up and down quarks?
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.
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.
Settled by: Parity-violating electron DIS on 48Ca at percent-level precision.
Kind: well-posed
Answer type: yes-no
References: (empty)
Literature status: open
Status note: (empty)
Posed since: (empty)