Speaker
Description
In this talk, we discuss the propagation of ultra-high energy cosmic rays (UHECRs), and
the resultant production of secondary diffuse neutrinos, in the presence of self-induced
confinement due to the excitation of the Non-Resonant Streaming Instability (NRSI)
near their sources.
UHECRs leaving their sources may induce a large electric current in the near-source
region, sufficient to excite a non-resonant streaming instability which may in turn confine
particles in the region. This effect leads to a modification of the spectrum of cosmic rays
released into the intergalactic medium.
We investigate under which conditions this instability may cause a low-energy sup-
pression of the released spectrum, due to the self-generation of magnetic perturbations
around the source.
We show that, for reasonable parameters of sources and surrounding IGM, this effect
facilitates the interpretation of the UHECR spectrum and composition above the ankle
as recently reported by the Pierre Auger Observatory and Telescope Array.
After exploring the conditions necessary for NRSI to confine particles, we introduce a
model that calculates the cosmological emissivity of cosmic rays, taking into account
the effect of NRSI, and based on a luminosity distribution that mirrors the observed
characteristics of candidate sources of UHECR.
Moreover, we address the contributions of confined protons to diffuse neutrino emis-
sions, which surpass the standard cosmogenic neutrino floor. This contribution is
quantitatively assessed for the first time in our study, and we present comparisons with
the existing experimental constraints provided by the IceCube experiment.
