Prompt atmospheric neutrino fluxes: perturbative QCD models and nuclear effects

Abstract

We evaluate the prompt atmospheric neutrino flux at high energies using three different frameworks for calculating the heavy quark production cross section in QCD: NLO perturbative QCD, k T factorization including low-x resummation, and the dipole model including parton saturation. We use QCD parameters, the value for the charm quark mass and the range for the factorization and renormalization scales that provide the best description of the total charm cross section measured at fixed target experiments, at RHIC and at LHC. Using these parameters we calculate differential cross sections for charm and bottom production and compare with the latest data on forward charm meson production from LHCb at 7 TeV and at 13 TeV, finding good agreement with the data. In addition, we Open Access, c The Authors. Article funded by SCOAP 3 .doi:10.1007/JHEP11 (2016)167 JHEP11 (2016)167 investigate the role of nuclear shadowing by including nuclear parton distribution functions (PDF) for the target air nucleus using two different nuclear PDF schemes. Depending on the scheme used, we find the reduction of the flux due to nuclear effects varies from 10% to 50% at the highest energies. Finally, we compare our results with the IceCube limit on the prompt neutrino flux, which is already providing valuable information about some of the QCD models.

Charm production and QCD analysis at HERA and LHC

“…for recent studies [268][269][270][271]. At some point astrophysical measurements of high-energy neutrinos may provide an upper limit on charm hadroproduction in the atmosphere and complement collider-based measurements.…”

Differential limit on the extremely-high-energy cosmic neutrino flux in the presence of astrophysical background from nine years of IceCube data

“…Prompt atmospheric neutrinos from short-lived heavy meson decays were modeled following Ref. [18], which predicted a higher prompt neutrino flux than recent calculations [19], and represent a conservative background estimate. The EHE neutrino-induced events were simulated by the JULIET package [20], which provides the cosmogenic (GZK) signal simulation sample as well as simulations of the astrophysical background events, whose spectrum is assumed to be described by an unbroken power law in the relevant energy region.…”

Neutrinos from cosmic ray interactions in the Sun

“…the charm production model of SIBYLL 2.3 [18]. This is a phenomenological model, in contrast to the modern calculations of the prompt flux in the atmosphere [19][20][21][22] that use state-of-the-art perturbative QCD. The SIBYLL prompt flux is larger than the perturbative fluxes, and may be close to the IceCube upper limit on the prompt flux [22,23].…”