相关论文: Photon-neutrino interactions
We compute the contribution of Kaluza-Klein graviton exchange to the cross section for photon-neutrino scattering. Unlike the usual situation where the virtual graviton exchange represents a small correction to a leading order electroweak…
We consider the gauge-boson sector of a locally SU(2) x U(1) invariant effective Lagrangian with ten dimension-six operators added to the Lagrangian of the Standard Model. These operators induce anomalous three- and four-gauge-boson…
We investigate Lambda(1520,3/2^-,D_03) photoproduction via the gamma N -> K Lambda^* reaction process. Using effective Lagrangians, we compute the total and differential cross sections as well as the dependence on the momentum transfer for…
The total hadronic cross-section sigma_gg(W) for the interaction of real photons, gg->hadrons, is measured for gg centre-of-mass energies 10<W<110 GeV. The cross-section is extracted from a measurement of the process e+e- -> e+e-g*g* ->…
In this paper the two-photon interactions at high energies are investigated considering different approaches for the QCD dynamics. In particular, we calculate the $\gamma^* \gamma^*$ total cross section in different theoretical approches…
We discuss the interaction of photons with neutrinos including two lepton loops. The parity violation in the gamma-nu to gamma-nu channel due to two lepton loops is substantially enhanced relative to the one lepton loop contribution.…
We study the neutrino-photon processes such as $\gamma\gamma\to \nu\bar{\nu}$ and $\nu\gamma\to \nu\gamma$ in a background magnetic field smaller than the critical magnetic field $B_c\equiv m_e^2/e$. Using Schwinger's proper-time method, we…
We discuss $\nu - \gamma$ interactions in the presence of a homogeneous magnetic field with energies less than pair production threshold. The neutrinos are taken to be massless with only standard-model couplings. The magnetic field fulfills…
The cross section for n+p -> d+gamma is calculated at energies relevant to big bang nucleosynthesis using the recently developed effective field theory that describes the two-nucleon sector. The E1 amplitude is computed up to NNNLO and…
The data on differential cross sections and photon-beam asymmetries for the $\gamma p \to K^+\Lambda(1520)$ reaction have been analyzed within a tree-level effective Lagrangian approach. In addition to the $t$-channel $K$ and $K^\ast$…
Using vector meson dominance we calculate the $\gamma\gamma$ total cross section from data on $pp$, $p\bar p$ and $\gamma p$ total cross sections. Our result agrees with recent high energy measurements performed by the L3 experiment at the…
We consider the Standard Model with an extended scalar sector, and study the possible effects of the physics underlying such a model using an effective lagrangian parametrization. It is found that certain two photon processes offer windows…
We give the amplitude for $\gamma\gamma \rightarrow \pi^+\pi^-\pi^0$ in leading order chiral perturbation theory. For the case of real photons we calculate the total and differential cross section. Furthermore, we give the dependence of the…
We calculate the cross section for inclusive prompt photon production in $\gamma\gamma$ collisions, i.e. the reaction $e^+e^-\to \gamma \gamma \to \gamma X$, in next-to-leading order QCD. We show that at LEP2 energies this cross section is…
We investigate neutrino-nucleus interactions at energies around 1 GeV. In this regime, the main contributions to the cross sections come from quasi-elastic and $\Delta$ production processes. Our formalism, based on the Impulse Approximation…
We study the neutrino-photon processes like $\gamma\gamma\to\nu\bar{\nu}$ in the presence of uniform external magnetic field for the case when neutrinos can couple to the electromagnetic field directly through their dipole magnetic moment…
Ultra-high energy ($E_\nu>10^8 $ GeV) neutrino-nucleon total cross sections $\sigma^{\nu N}$ are estimated from a soft non-perturbative model complemented by an approximate QCD evolution, explicitly calculated. The resulting asymptotic…
We compute the cross section for neutrino-photon scattering taking into account a neutrino mass. We explore the possibility of using intense neutrino beams, such as those available at proposed muon colliders, together with high powered…
The cross section for different processes induced by $e^+e^-$ annihilation, in the kinematical limit $\beta_{\mu}\approx\beta_{\pi}=(1-m_{\pi}^2/\epsilon^2)^{1/2}\sim 1$, is calculated taking into account first order corrections to the…
The reaction $\gamma+p\to\gamma'+p+\pi^0$ has been suggested as a means to deduce the $\Delta^+$ magnetic moment. The cross section for this process is estimated in both the constituent quark model and an effective Lagrangian procedure. The…