Structure function of a bound nucleon versus its virtuality
In plain words
By detecting the partner nucleon that recoils backward, experiments can select collisions on a nucleon that was moving fast inside deuterium. This tests directly whether fast-moving bound nucleons have modified quark distributions.
Precise statement
Measure the struck-nucleon structure function in $d(e, e' N_s) X$ as a function of x' and spectator momentum $p_s$ from $0.25\text{ to }0.6\ \mathrm{GeV}/c$ (JLab BAND and LAD experiments), and determine whether $F2_{\mathrm{bound}}/F2_{\mathrm{free}}$ scales with the virtuality $v = (p^\mu p_\mu - M^2)/M^2$ as SRC models predict. Answer: the measured function $F2_{\mathrm{bound}}/F2_{\mathrm{free}}(x', v)$.
What would settle it
Spectator-tagged DIS with final-state interactions constrained by the measured angular dependence of the spectator nucleon.
Related problems
- Special case of Physical origin of the EMC effect