Mapping the dominant regions of the phase space associated with cc production relevant for the prompt atmospheric neutrino flux

摘要

We present a detailed mapping of the dominant kinematical domains contributing to the promptatmospheric neutrino flux at high neutrino energies by studying their sensitivity to the cuts on severalkinematical variables crucial for charm production in cosmic ray scattering in the atmosphere. Thisincludes the maximal center-of-mass energy for proton-proton scattering, the longitudinal momentumfractions of partons in the projectile (cosmic ray) and target (nucleus of the atmosphere), the Feynman x_Fvariable, and the transverse momentum of charm quark/antiquark. We find that the production of neutrinoswith energies larger than E_ν > 10~7 GeV is particularly sensitive to the c.m. energies larger than the ones atthe LHC and to the longitudinal momentum fractions in the projectile 10~(−8) < x < 10~(−5). Clearly, these areregions where we do not control the parton, in particular, gluon, densities. We also analyze thecharacteristic theoretical uncertainties in the charm production cross section coming from its QCDmodeling. The precision data on the prompt atmospheric neutrino flux can efficiently constrain themechanism of heavy quark production and underlying QCD dynamics in kinematical ranges beyond thereach of the current collider measurements.