相关论文: Fermi Pulsars and the Cosmic Ray Knee
(The systematics of photon absorption cross sections in nuclei and small metal particles are examined as a function of the number of constituent fermions $A$. It is pointed out that the shell-structure-linked oscillations in the full width…
The photon-absorption edge in a weakly interacting one-dimensional electron gas is studied, treating backscattering of conduction electrons from the core hole exactly. Close to threshold, there is a power-law singularity in the absorption,…
In experiment on the study of the quasielastic pion-proton scattering at large momentum transfer on nuclei the proton Fermi-momentum distributions have been analysed in plane-wave approximation for light nuclei $^6$Li, $^7$Li and $^{12}$C.…
The observed velocities of radio pulsars, which range in the hundreds kilometers per second, and many of which exceed 1000 km/s, are not explained by the standard physics of the supernova explosion. However, if a sterile neutrino with mass…
In models with extra dimensions the fundamental scale of gravity M_D could be of order TeV. In that case the interaction cross section between a cosmic proton of energy E and a dark matter particle \chi will grow fast with E for center of…
Nuclear stopping has been investigated in central symmetric nuclear collisions at intermediate energies. Firstly, it is found that the isotropy ratio, Riso, reaches a minimum near the Fermi energy and saturates or slowly increases depending…
The energy spectrum of nucleons in high-density nuclear matter is investigated in the framework of relativistic meson-nucleon many-body theory, employing the $1/N$ expansion method. The coupling of the nucleon with the particle-hole…
Nuclei with spin $I \ge 1$ have a weak quadrupole moment which leads to tensor contribution to the parity non-conserving interaction between nuclei and electrons. We calculate this contribution for Yb$^+$, Fr and Ra$^+$ and found it to be…
Neutron stars, just after their formation, are surrounded by expanding, dense, and very hot envelopes which radiate thermal photons. Iron nuclei can be accelerated in the wind zones of such energetic pulsars to very high energies. These…
It has been argued recently that the so-called nuclear modification factor ($R_{AA}$) is an observable useful for identifying the quark-gluon plasma. We discuss the effect of Fermi motion in nuclei on $R_{AA}$ at CERN SPS and BNL RHIC…
We show that the second knee in the cosmic ray spectrum (i.e. the steepening occurring at $E\simeq 4\times 10^{17}$ eV) could be related to drift effects affecting the heaviest nuclear component, the iron group nuclei, in a scenario in…
Recently, LHAASO has detected five microquasars with high confidence, which are associated with SS 433, V4641 Sgr, GRS 1915+105, MAXI J1820+070, and Cygnus X-1, respectively. Except for Cygnus X-1, the maximum energies of gamma-ray photons…
The Sun stands out as the closest and clearest astrophysical accelerator of cosmic rays, while other objects within and beyond the galaxy remain enigmatic. It is probable that the cosmic ray spectrum and mass components from these celestial…
A calculation based on flat spacetime symmetries shows how there can be two quantum phases. For one, extreme phase change determines a conventional classical trajectory and four-momentum, i.e. mass times four-velocity. The other phase…
We study the physical conditions for the occurrence of ferromagnetic instability in a neutral plasma of fermions. We consider a system of two species $M$ and $Y$ which are oppositely charged under a local $U(1)_{X}$, with $M$ much lighter…
The accretion of galactic gas is regarded as the source of the giant luminosity of quasars. The gravitational energy converts itself into radiation close to the Schwarzschild horizon of the central supermassive black hole with efficiency of…
The existence of a "knee" at energy ~1 PeV in the cosmic-ray spectrum suggests the presence of Galactic PeV proton accelerators called "PeVatrons". Supernova Remnant (SNR) G106.3+2.7 is a prime candidate for one of these. The recent…
An accreting supermassive blackhole, the central engine of active galactic nucleus (AGN), is capable of exciting extreme amplitude Alfven waves whose wavelength (wave packet) size is characterized by its clumpiness. The pondermotive force…
A sudden steepening of the cosmic-ray energy spectrum (the knee) is observed at an energy of about 3 PeV (1 PeV = $10^{15}$ eV). The experimental study of the PeV cosmic rays has intensified greatly during the last 3 years. The recent…
There exist field theory models where the fermionic energy-momentum tensor contains a term proportional to g_{\mu\nu}\bar{\Psi}\Psi which can be responsible for a dark matter to dark energy transmutation. We study some cosmological aspects…