Athermal Jamming vs Thermalized Glassiness in Sheared Frictionless Particles

Numerical simulations of soft-core frictionless disks in two dimensions are carried out to study behavior of a simple liquid as a function of thermal temperature $T$, packing fraction $\phi$, and uniform applied shear strain rate $\dot\gamma$. Inferring the hard-core limit from our soft-core results, we find that it depends on the two parameters $\phi$ and $T/\dot\gamma$. $T/\dot\gamma\to 0$ defines the athermal limit in which a shear driven jamming transition occurs at a well defined $\phi_J$. $T/\dot\gamma\to\infty$ defines the thermalized limit where an equilibrium glass transition may take place at a $\phi_G$. This conclusion argues that athermal jamming and equilibrium glassy behavior are not controlled by the same critical point. Preliminary results suggest $\phi_G <\phi_J$.