相关论文: Ultrahigh energy neutrino interactions and weak-sc…
Cosmic ray events above $10^{20}$ eV are on the verge of confronting fundamental particle physics. The neutrino is the only candidate primary among established particles capable of crossing 100 Mpc intergalactic distances unimpeded. The…
It has been suggested that the characteristic energy of string models may be considerably lower than the observed Planck mass. In such schemes, the unification of interactions takes place around the string scale, perhaps as low as a few…
We show that future detectors of ultrahigh-energy cosmic-ray neutrinos will be able to measure neutrino-nucleon cross section at energies as high as 10^{11}GeV or higher. We find that the flux of up-going charged leptons per unit surface…
The suggestion is made that air showers with energies beyond the Greisen-Zatsepin-Kuz'min spectral cut-off may have primary vertices some 6 km lower in height than those of proton initiated showers with energies below the GZK cut-off. This…
The origin of the ultra high energy cosmic ray (UHECR) showers has remained as a mystery among particle physicists and astrophysicists. In low scale gravity models, where the neutrino-nucleon cross section rises to typical hadronic values…
String unification at a scale of a few tens of TeV explains the existence of cosmic ray interactions beyond the Greisen-Zatsepin-Kuzmin (GZK) cutoff. Trans-GZK cosmic rays are neutrinos which can penetrate the cosmic microwave background.…
Ultra high energy cosmic rays (UHECR) pose a problem either for particle physics or for astrophysics (or for both) by the unexpectedly high number of cosmic ray showers observed with energy above about 5x10^{19}eV, the…
The ultrahigh energy neutrino cross section is well understood in the standard model for neutrino energies up to 10$^{12}$ GeV. Test of neutrino oscillations ($\nu_\mu\leftrightarrow\nu_\tau$) from extragalactic sources of neutrinos are…
Extremely high energy neutrinos propagating in the atmosphere or in the Earth can originate horizontal or upgoing air-showers, respectively. We calculate the acceptances (event rate/flux) for detecting both types of events by fluorescence…
The origin and nature of ultrahigh-energy cosmic ray events, above the Greisen-Zatsepin-Kuzmin (GZK) cutoff energy, constitute a long-standing, unsolved mistery. Neutrinos are proposed candidates but their standard interactions with matter…
After a short review of the ultrahigh energy cosmic ray puzzle - the apparent observation of cosmic rays originating from cosmological distances with energies above the expected Greisen-Zatsepin-Kuzmin cutoff 4x10^{19} eV - we consider…
Ultrahigh energy neutrinos can be used to explore the physics at the TeV scale. We study the neutrino-nucleon cross section in models with extra dimensions and the fundamental scale at the TeV. In particular, we discuss the production of…
Future detection of ultrahigh-energy neutrinos will open a new window on physics at center-of-mass energy 10^5 GeV and higher. In particular, observations of neutrino-initiated showers will help test the Standard Model predictions for the…
We show that all features of the ultrahigh energy cosmic ray spectrum from 10^{17} eV to 10^{21} eV can be described with a simple power-like injection spectrum of protons under the assumption that the neutrino-nucleon cross-section is…
In models based on large extra dimensions where massive spin 2 exchange can dominate at high energies, the neutrino-proton cross section can rise to typical hadronic values at energies above 10^20 eV. The neutrino then becomes a candidate…
Neutrinos are key to probing the deep structure of matter and the high-energy Universe. Yet, until recently, their interactions had only been measured at laboratory energies up to about 350 GeV. An opportunity to measure their interactions…
We predict the neutrino-nucleon cross section at ultrahigh energies relevant in connection with the search for high-energy cosmic neutrinos. Our investigation, employing the color-dipole picture, among other things allows us to…
Cross sections for the interactions of ultrahigh-energy neutrinos with nucleons are evaluated in light of new information about nucleon structure functions. For $10^{20}$--eV neutrinos, the cross section is about 2.4 times previous…
A review is given on the recently proposed idea that air showers with energy $> 10^{20}$ eV beyond the Greisen-Zatsepin-Kuz'min cut-off may be due to neutrinos having acquired a strong interaction at these energies, as suggested by the…
The theoretical status of the neutrino-nucleon cross section is reviewed for incident neutrino energies up to E_nu=10^12 GeV, including different approaches to high energy extrapolations. Nonstandard model physics may play a role at…