New physics, the cosmic ray spectrum knee, and pp cross section measurements Aparna Dixit, Pankaj Jain, Douglas W. McKay and Parama Mukherjee Eur. Phys. J. C, 68 3-4 (2010) 573-580 Published online: 15 July 2010 DOI: 10.1140/epjc/s10052-010-1382-7