Probing nuclear structure with mean transverse momentum in relativistic isobar collisions

Transverse momentum (${p}_{\ensuremath{\perp}}$) generation in relativistic heavy-ion collisions is sensitive to the initial geometry and final-state bulk evolution. We demonstrate with hydrodynamic calculations that mean ${p}_{\ensuremath{\perp}}$ ratio (${R}_{\ensuremath{\langle}{p}_{\ensuremath{\perp}}\ensuremath{\rangle}}$) between highly similar isobar $_{44}^{96}\mathrm{Ru}+_{44}^{96}\mathrm{Ru}$ $_{40}^{96}\mathrm{Zr}+_{40}^{96}\mathrm{Zr}$ insensitive evolution remains small difference nuclear structure (neutron skin deformation) Ru Zr nuclei. further find deformation can produce an anticorrelation ${R}_{\ensuremath{\langle}{p}_{\ensuremath{\perp}}\ensuremath{\rangle}}$ eccentricity (or elliptic flow) central collisions. These findings suggest systems be used measure neutron thickness parameters, which can, turn, constrain symmetry energy slope parameter.