NUC
In the literature: open
Is the EMC effect different for up and down quarks?
In plain words
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 statement
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.
What would settle it
Parity-violating electron DIS on 48Ca at percent-level precision.
Related problems
- Special case of Physical origin of the EMC effect