Abstract
Charmed mesons may be produced when a primary cosmic ray or the leading hadron in an air shower collide with an atmospheric nucleon. At energies their decay length becomes larger than 10 km, which implies that they tend to interact in the air instead of decaying. We study the collisions of long-lived charmed hadrons in the atmosphere. We show that -proton diffractive processes and partonic collisions of any where the charm quark is a spectator have lower inelasticity than -proton collisions. In particular, we find that a meson deposits in each interaction just around 55% of the energy deposited by a pion. On the other hand, collisions involving the valence -quark (its annihilation with a sea -quark in the target or -quark exchange in the channel) may deposit most of the meson energy, but their frequency is low (below 0.1% of inelastic interactions). As a consequence, very energetic charmed hadrons may keep a significant fraction of their initial energy after several hadronic interactions, reaching much deeper in the atmosphere than pions or protons of similar energy.
- Received 15 October 2010
DOI:https://doi.org/10.1103/PhysRevD.83.034027
© 2011 American Physical Society