相关论文: Photon-neutrino interactions
We have investigated non-standard $\nu \bar \nu \gamma $ and $\nu \bar \nu \gamma \gamma$ couplings via $\nu \bar \nu$ production in a $\gamma p$ collision at the LHC. We obtain 95\% confidence level bounds on $\nu \bar \nu \gamma $ and…
A short review of experimental and theoretical results on the large angle cross sections \gamma\gamma --> {two mesons} and the form factors \gamma*\gamma --> P={pi, \eta, \eta'} is given.
A gauge-invariant model is constructed for the $\gamma p \to K^+\Lambda(1690)$ reaction within a tree-level effective Lagrangian approach with the purpose to understand the underlying production mechanisms and to study the resonance…
Differential cross sections and photon-beam asymmetries for the gamma p -> pi- Delta++(1232) reaction have been measured for 0.7<cos(theta)<1 and Egamma=1.5-2.95 GeV at SPring-8/LEPS. The first-ever high statistics cross section data are…
Differential cross sections for $\gamma p \to K^+\Lambda(1405)$ and $\gamma p \to K^+\Sigma^0(1385)$ reactions have been measured in the photon energy range from 1.5 to 2.4 GeV and the angular range of $0.8<\cos(\Theta)<1.0$ for the $K^+$…
Cross sections for proton inelastic collision with different nuclei are described within the Glauber and multiple scattering approximations. A significant difference between approximate `Glauber' formula and exact calculations with a…
In this letter we propose a possible mechanism of left- and right-handed neutrino couplings to photons, which arises quite naturally in non-commutative gauge field theory. We estimate the predicted additional energy-loss in stars induced by…
A high-energy lepton-lepton collider will give us a unique possibility to study e-gamma and gamma-gamma interactions at high energies. The high-energy photons can be generated by Compton back-scattering of laser light on the high-energy…
We compute the one-loop helicity amplitudes for low-energy $\nu\gamma\to\nu\gamma$ scattering and its crossed channels in the standard model with massless neutrinos. In the center of mass, with $\sqrt{s} = 2\omega\ll 2m_e$, the cross…
The $\Sigma(1385)$ resonance, or $\Sigma^*$, is well-known as part of the standard baryon decuplet with spin $J=3/2$. Measurements of the reaction $\gamma p \to K^+ \Sigma^{*0}$ are difficult to extract due to overlap with the nearby…
In this work, an improved quark model approach to the $\omega$ meson photo-production with an effective Lagrangian is presented. The {\it t}-channel {\it natural}-parity exchange is taken into account through the Pomeron exchange, while the…
A unified approach to total cross-sections, based on the QCD contribution to the rise with energy, is presented for the processes $pp$, $p{\bar p}$, $\gamma p, \gamma \gamma, e^+e^- \to hadrons$. For proton processes, a discussion of the…
Differential cross sections and photon beam asymmetries for the gamma p rightarrow K+ Lambda and gamma p rightarrow K+ Sigma0 reactions have been measured in the photon energy range from 1.5 GeV to 2.4 GeV and in the angular range from…
Proton-activation reactions on natural and enriched palladium samples were investigated via the activation technique in the energy range of E_p=2.75 MeV to 9 MeV, close to the upper end of the respective Gamow window of the gamma process.…
A recently developed model for $\rho$-meson propagation in dense hadronic matter is applied to total photoabsorption cross sections in $\gamma$-proton and $\gamma$-nucleus reactions. Within the vector dominance model the photon coupling to…
We discuss present predictions for the total $\gamma \gamma$ and $\gamma p $ cross-sections, highlighting why predictions differ. We present results from the Eikonal Minijet Model and improved predictions based on soft gluon resummation.
It is shown that in reaction \gamma\gamma\to\ell^+\ell^-+\nu's at \sqrt{s}>200 GeV with polarized photons, large and well observable differences arise in the distribution of positive and negative charged leptons (\ell=\mu^\pm, e^\pm),…
The reaction e+ e- -> e+ e- gamma* gamma* -> e+ e- hadrons is analysed for quasi-real virtual photons using data collected by the L3 detector during the LEP high energy runs at sqrt(s) = 183 and 189 GeV. Preliminary results on the cross…
The flux of $\gamma$ rays is measured with unprecedented accuracy by the $\textit{Fermi}$ Large Area Telescope from 100 MeV to almost 1 TeV. In the future, the Cherenkov Telescope Array will have the capability to measure photons up to 100…
Neutrino-photon interactions in the presence of an external homogeneous constant electromagnetic field are studied. The $\nu \nu \gamma $ amplitude is calculated in an electromagnetic field of the general type, when the two field invariants…