We have calculated the decay τ → νπ(K)γ. We present the photon energy spectrum, the meson-photon invariant mass spectrum and the integrated rate as a function of a photon energy cut or an invariant mass cut. Both the internal bremsstrahlung and the structure dependent radiation have been taken into account. To this aim we have parametrized the form factors FV and FA, which determine the structu...

Heavy quark energy loss in a hot QCD plasma is computed taking into account the competing effects due to suppression of zeroth order gluon radiation bellow the plasma frequency and the enhancement of gluon radiation due to transition energy loss and medium induced Bremsstrahlung. Heavy quark medium induced radiative energy loss is derived to all orders in opacity, (L/λg) . Numerical evaluation ...

Models of relativistic jets filled with ultrarelativistic pair plasma have turned out to be very suitable to explain the broadband radiation of γ-ray blazars. Given the initial injection and cooling of ultrarelativistic pair plasma in an AGN jet has occurred, producing the observed high-energy γ-ray radiation, we investigate the further evolution of the pair plasma as it continues to move out f...

A synchrotron radiation (SR) facility typically consists of an injector, a storage ring, and SR beamlines. The latter two features are unique to SR facilities, when compared to other types of accelerator facilities. The SR facilities have the characteristics of low injection beam power, but high stored beam power. The storage ring is generally above ground with people occupying the experimental...

The effect of external as well as internal bremsstrahlung radiation in H ! ZZ ! 4e channel is studied in full detector simulation. A method is proposed for external and internal bremsstrahlung recovery, allowing us to use 95% of electrons within j E=pgen 1 j 0.2. It is shown that traditional E=p and isolation cuts can be implemented with 90% efficiency, but that precise mass reconstruction is a...

Experimental results for the bremsstrahlung energy loss of 149, 207, and 287 GeV electrons in thin Ir, Ta, and Cu targets are presented. For each target and energy, a comparison between simulated values based on the Landau-Pomeranchuk-Migdal ~LPM! suppression of incoherent bremsstrahlung is shown. For the electron energies investigated, the LPM effect enters the quantum regime where the recoil ...

Top quark events in hadron collisions often contain additional hadronic jets from gluon bremsstrahlung off the quarks and gluons in the hard subprocesses. Such extra jets must be taken into account in attempts to reconstruct the momentum of the top quark from those of its decay products. We have performed a complete calculation of gluon radiation in top production and decay at the Fermilab Teva...

A theoretical analysis of radiation spectra produced during the coherent interaction of nonrelativistic electrons with crystals has been carried out. The output intensity has been found to be the result of interference between two distinguishable phenomena, coherent Bremsstrahlung and parametric x-ray radiation. The latter is determined by a coherent summation of transition radiation from elect...

Bremsstrahlung of photons from highly relativistic electrons is investigated. The cross section of the processes, which is suppressed due to a multiple scattering of an emitting electron in dense media (LPM effect) and due to photon interaction with electrons of a medium, is calculated with an accuracy up to ”next to leading logarithm” and with the Coulomb corrections taken into account. Making...

Soft gluon radiation induced by multiple scattering of a fast quark or gluon propagating through QCD matter is discussed. After revisiting the Landau-Pomeranchuk-Migdal effect in QED we show that large formation times of bremsstrahlung quanta determine the QCD radiation intensity (in analogy to QED) and derive the gluon energy spectrum. Coherent suppression takes place as compared to the Bethe-...