https://doi.org/10.1140/epjc/s10052-010-1382-7
Regular Article - Theoretical Physics
New physics, the cosmic ray spectrum knee, and pp cross section measurements
1
Physics Department, PSIT, Kanpur, India
2
Department of Physics, IIT Kanpur, Kanpur, 208016, India
3
Department of Physics & Astronomy, University of Kansas, Lawrence, KS, 66045, USA
4
School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, 11794, USA
* e-mail: pkjain@iitk.ac.in
Received:
21
March
2010
Published online:
15
July
2010
We explore the possibility that a new-physics interaction can provide an explanation for the knee just above 106 GeV in the cosmic ray spectrum. We model the new-physics modifications to the total proton–proton cross section with an incoherent term that allows for missing energy above the scale of new physics. We add the constraint that the new physics must also be consistent with published pp cross section measurements, using cosmic ray observations, an order of magnitude and more above the knee. We find that the rise in cross section required at energies above the knee is radical. The increase in cross section suggests that it may be more appropriate to treat the scattering process in the black disc limit at such high energies. In this case there may be no clean separation between the standard model and new-physics contributions to the total cross section. We model the missing energy in this limit and find a good fit to the Tibet III cosmic ray flux data. We comment on testing the new-physics proposal for the cosmic ray knee at the Large Hadron Collider.
© Springer-Verlag / Società Italiana di Fisica, 2010
