Upper Limits on the Cosmic Neutrino Background from Cosmic Rays
Mar Císcar-Monsalvatje, Gonzalo Herrera, Ian M. Shoemaker
备注：
Matches published version in PRD. Added comparison of experimentally measured neutrino-proton cross section with our analytical expression; added limits on CnuB overdensities from Galaxy clusters and the critical density of the Universe
河外和银河系宇宙射线在传播至地球期间与宇宙中微子背景发生散射，产生被加速至更高能量的遗迹中微子流。若星系中存在遗迹中微子超密度，且中微子质量足够大，此通量可能被高能中微子实验探测到。对于质量为 $m_ν \sim 0.1$ eV 的最轻中微子，我们得出局部遗迹中微子超密度的上限约为 $10^{13}$，以及 TXS 0506+056 处遗迹中微子超密度的上限约为 $10^{10}$。像 GRAND 或 IceCube-Gen2 这样的未来实验可能将这些约束改善数个数量级。
英文摘要：
Extragalactic and galactic cosmic rays scatter with the cosmic neutrino background during propagation to Earth, yielding a flux of relic neutrinos boosted to larger energies. If an overdensity of relic neutrinos is present in galaxies, and neutrinos are massive enough, this flux might be detectable by high-energy neutrino experiments. For a lightest neutrino of mass $m_ν \sim 0.1$ eV, we find an upper limit on the local relic neutrino overdensity of $\sim 10^{13}$ and an upper limit on the relic neutrino overdensity at TXS 0506+056 of $\sim 10^{10}$. Future experiments like GRAND or IceCube-Gen2 could improve these bounds by orders of magnitude.
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We present an introductory lecture on general features of cosmic rays, for non-experts, and some recent developments concerning cascade equations for air shower developments.
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The muon charge ratio of ultrahigh energy cosmic rays may provide information to detect the composition of the primary cosmic rays. We propose to extract the charge information of high energy muons in very inclined extensive air showers by analyzing their relative lateral positions in the shower transverse plane.
Stable lumps of quark matter may be present in cosmic rays at a flux level, which can be detected by high precision cosmic ray experiments sensitive to anomalous "nuclei" with high mass-to-charge ratio. The properties of these lumps, called strangelets, are described, and so is the production and propagation of strangelets in cosmic rays. Two experiments underway which are sensitive to a strangelet flux in the predicted range are briefly described. Finally it is summarized how strangelets circumvent the acceleration problem encountered by conventional candidates for ultra-high energy cosmic ra…
Determination of mass composition of high energy cosmic rays is one of the greatest challenge in modern astrophysics. All of previous methods for finding the mass composition of primary cosmic rays in a surface array at least require two independent measurements (e.g. muon and electron components) of extensive air showers (EAS). Here a new statistical parameter is introduced which can be used to determine the mass composition of vertical downward cosmic rays in a simple surface array. The most interesting thing about the new parameter is that it does not need two independent measurements and c…
Ultra high energy cosmic ray events presently show a spectrum, which we interpret here as galactic cosmic rays due to a starburst in the radio galaxy Cen A pushed up in energy by the shock of a relativistic jet. The knee feature and the particles with energy immediately higher in galactic cosmic rays then turn into the bulk of ultra high energy cosmic rays. This entails that all ultra high energy cosmic rays are heavy nuclei. This picture is viable if the majority of the observed ultra high energy events come from the radio galaxy Cen A, and are scattered by intergalactic magnetic fields acros…
