相关论文: MeV gamma rays from Q-ball decay
We consider decaying dark matter with masses $10^{7} \lesssim M \lesssim 10^{16}$ GeV, as a source of ultra-high energy (UHE) gamma rays. Using recent limits on UHE gamma-ray flux for energies $E_\gamma > 2 \cdot 10^{14}$ eV, provided by…
A coupled-channel analysis has been performed to identify the spectrum of scalar mesons. The data include BESIII data on radiative $J/\psi$ decays into $\pi^0\pi^0$,$K_SK_S$, $\eta\eta$, and $\omega\phi$, 15 Dalitz plots from $\bar pN$…
We analyse data on pi pi and gamma gamma scattering below 700 MeV within an improved analytic K-matrix model. This model is based on an effective theory with couplings between resonances, hadrons and photons. The two-photon decay of a…
Scalar mesons are a key expression of the infrared regime of QCD. The lightest of these is the $\sigma$. Now that its pole in the complex energy plane has been precisely located, we can ask whether this state is transiently ${\bar q}q$ or…
In the internal shock model of gamma ray bursts ultrahigh energy muons, pions, neutrons and kaons are likely to be produced in the interactions of shock accelerated relativistic protons with low energy photons (KeV-MeV). These particles…
Non topological solitons, Q-balls can arise in many particle theories with U(1) global symmetries. As was shown by Cohen et al. \cite{Qballscohen}, if the corresponding scalar field couples to massless fermions, large Q-balls are unstable…
In the framework of the relativistic and gauge invariant spectral integral technique, we calculate radiative decays rho(770)-> gamma pi(140) and omega(780)-> gamma pi(140) supposing all mesons (pi, rho and omega) to be quark-antiquark…
The diphoton excess around $m_S=750$ GeV observed at ATLAS and CMS can be interpreted as coming from $S=H$ and $A$, the neutral components of a second Higgs doublet. If so, then the consistency of the light Higgs decays with the Standard…
In a previous paper the spectrum of positrons produced by matter initially at rest falling onto a massive compact object was calculated. In this paper this calculation is generalized to obtain both the spectrum of in-flight positron…
When dense high-energy lepton bunches collide, the beam particles can experience rest-frame electromagnetic fields which greatly exceed the QED critical one. Here it is demonstrated that beamstrahlung efficiently converts lepton energy to…
A variety of strong and electroweak interaction properties of the pion and the light scalar sigma meson are computed in a relativistic quark model. Under the assumption that the resulting coupling of these mesons to the constituent quarks…
We investigate vacuum stability and Q-ball formation in the Type II seesaw model by considering the effective potential for scalar fields, taking into account renormalization effects. We find that the quartic coupling for the triplet Higgs…
At the Mott transition of a quark/meson plasma, mesons become unbound. This leads to the effect of critical scattering, which is studied by investigating photon pair production due to the process $q\bar q\to\gamma\gamma$. This process can…
Diffuse gamma rays probe the highest-energy processes at the largest scales. Here we derive model-independent constraints on the hadronic contribution to the Galactic and extragalactic gamma-ray spectra in the energy range 50 MeV < E_gamma…
We present a detailed study of the two-body strong decays of light mesons. Both the space part and the spin-flavor-color part of the wave functions are generated algebraically and closed forms are obtained for all decays. Experimental…
Gamma-ray bursts are produced by the dissipation of the kinetic energy of a highly relativistic fireball, via the formation of a collisionless shock. When this happens, Ultra High Energy Cosmic Rays up to 10^20 eV are produced. I show in…
We point out the following astrophysical consequences of a tau neutrino with mass in the MeV range: (i) if it has a small electric charge which will allow it to become a cold dark matter of the universe, then present limits on the 511 KeV…
The Affleck-Dine mechanism, which is one of the most attractive candidates for the baryogenesis in supersymmetric theories, often predicts the existence of baryonic Q balls in the early universe. In this scenario, there is a possibility to…
Cosmic rays (protons and other atomic nuclei) are believed to gain energies of petaelectronvolts (PeV) and beyond at astrophysical particle accelerators called 'PeVatrons' inside our Galaxy. Although a characteristic feature of a PeVatron…
We have observed atmospheric gamma rays from 30GeV to 8TeV, using emulsion chambers at balloon altitudes, accumulating the largest total exposure in this energy range to date, SOT ~ 6.66m^2.sr.day. At very high altitudes, with residual…