Abstract
Recent simulations have predicted that near jamming for collections of spherical particles, there will be a discontinuous increase in the mean contact number at a critical volume fraction . Above , and the pressure are predicted to increase as power laws in . In experiments using photoelastic disks we corroborate a rapid increase in at and power-law behavior above for and . Specifically we find a power-law increase as a function of for with an exponent around 0.5, and for with an exponent around 1.1. These exponents are in good agreement with simulations. We also find reasonable agreement with a recent mean-field theory for frictionless particles.
- Received 23 October 2006
DOI:https://doi.org/10.1103/PhysRevLett.98.058001
©2007 American Physical Society