相关论文: Hard-Photon Emission in e+e- to bar-f f with Reali…
We present a simple method of removing the singularities associated with soft photon emission to all orders in perturbation theory through exponentiation, while keeping a consistent description of hard photon emission. We apply this method…
The fermion mass effects in e+ e- --> 4f and in the corresponding bremsstrahlung reactions in the presence of realistic cuts are studied. It is shown that, for some four--fermion final states, the mass effects become sizeable to the extent…
We accomplish our efforts to obtain predictions for all four-fermion final states of e+ e- annihilation and the corresponding bremsstrahlung reactions which are possible in the framework of the Standard Model. For this purpose we have…
An improved efficient method of calculating the hard bremsstrahlung correction to e^+ e^- -> 4f for non-zero fermion masses is presented. The non-vanishing fermion masses allow us to perform the phase space integrations to the very…
The rate for the production of a pair of massive fermions in $e^+ e^-$ annihilation plus real or virtual radiation of a pair of massless fermions is calculated analytically. The contributions for real and virtual radiation are displayed…
We review the results on representing the differential cross section for W-pair production, including W decay and hard-photon bremsstrahlung, in terms of a Born-form approximation of fairly simple analytic form.
The $O(\alpha)$ corrections to $\gamma\gamma --> f \bar f$ in the Standard Model are calculated for arbitrary, light fermions $f$. The relevant analytical results are listed in a form that is appropriate for practical applications, and…
We study predictions for the reaction $e^+e^- \to {\bar \nu} \nu (n \gamma)$. The complete one-loop corrections are taken into account and higher order contributions, in particular those for the observed real photons, are added whenever…
Soft-photon emission rates are calculated within the linear sigma model. The investigation is aimed at answering the question to which extent the emissivities map out the phase structure of this particular effective model of strongly…
The production of photon pairs in $e^+e^-\rightarrow f \bar f \gamma\gamma$ processes is studied using exact helicity amplitudes at tree level. Total cross sections, including initial state radiation effects, are given. They are presented…
Photon emission arising in the course of transition between the states of quark-gluon and hadron plasma has been considered. Single-photon distributions and two-photon correlations in central rapidity region have been calculated for heavy…
We calculate the process $\gamma \gamma \rightarrow e^- \bar{\nu}_e u \bar{d}$ with the full set of Feynman diagrams. We consider different implementations of the $W$ width and different combinations of the photon polarisations. The results…
Soft or collinear photon emission potentially poses numerical problems in the phase-space integration of radiative processes. In this paper, a general subtraction formalism is presented that removes such singularities from the integrand of…
Analytic formulae are derived for the complete photon energy spectrum due to QED corrections to fermion pair production in case of a limited angular acceptance for the final state fermions. After a numerical integration over the energy of…
A theoretical model of the reactions e+ e- --> K+ K- gamma and e+ e- --> K0 K0bar gamma has been derived. The strong interaction between kaons is taken into account using a general form of the K Kbar scattering amplitude. It is shown that…
The emission of $\nu\bar\nu$ pairs off electrons in a polarized ultra-intense electromagnetic (e.g.\ laser) wave field is analyzed. We elaborate on the significance of non-linear electrodynamics effects (i.e., multi-photon processes) and…
The proposed $e^+e^-$-collider FCC-ee aims at an unprecedented accuracy for $e^+e^-$ collisions into fermion pairs at the $Z$ peak, based on about $10^{13}$ events. The S-matrix approach to the $Z$ boson line shape allows the…
Photon energy moments in B -> X_s+\gamma and the impact of experimental cuts are analyzed, including the biases exponential in the effective hardness missed in the conventional OPE. We incorporate the perturbative corrections fully…
We present a sample of results for the cross sections of several processes of low energetic $e^+e^-$ annihilation into final states containing pions accompanied by one or two photons, or a light lepton pair. The results, which have been…
Absorption of high-energy $\bar{\nu}_e$ over electrons above the W boson production threshold is reexamined. It is pointed out that, in the case of photon emissions along the direction of incident high-energy $\bar{\nu}_e$, the…