Transverse-velocity scaling of femtoscopy in $\sqrt{s}=7TeV$ proton–proton collisions

Although transverse-mass scaling of femtoscopic radii is found to hold to a good approximation in heavy-ion collision experiments, it is seen to fail for high-energy proton–proton collisions. It is shown that if invariant radius parameters are plotted versus the transverse velocity instead, scaling with the transverse velocity is seen in $\sqrt{s}=7$ TeV proton–proton experiments. A simple semi-classical model is shown to qualitatively reproduce this transverse velocity scaling. (paper)