相关论文: Weak Boson Production Amplitude Zeros; Equalities …
The Standard Model amplitudes for processes where one or more gauge bosons are emitted exhibit zeros in the angular distributions. The theoretical and experimental aspects of these radiation amplitude zeros are reviewed and some recent…
A comparative study of amplitude zeros in $W\gamma$ and $WZ$ production in hadronic collisions is presented. The Standard Model amplitude for $q_1 \bar q_2 \rightarrow W^\pm Z $ at the Born-level is shown to exhibit an approximate zero…
We demonstrate that the Standard Model amplitude for $f_1 \bar f_2 \rightarrow W^\pm Z $ at the Born-level exhibits an approximate zero located at $\cos\theta = (g^{f_1}_{-} + g^{f_2}_{-}) / (g^{f_1}_{-} - g^{f_2}_{-})$ at high energies,…
Propagation of particles with emission of arbitrary number of identical bosons all being at rest is considered. It is shown that in certain models the tree-level amplitudes for production of $n$ scalar bosons by two incoming particles are…
We present the one-loop QCD corrections to the helicity amplitudes for the processes $q\qb \to W^+ W^-, Z Z, W^\pm Z, W^\pm \gamma$, or $Z \gamma$, including the subsequent decay of each massive vector boson into a pair of leptons. We also…
Standard radiation zeros arise from the factorization properties of tree-level amplitudes involving a massless photon and can occur when all charged particles in the initial and final state have the same sign. We investigate how several…
The cross section for producing $WZ$ pairs at hadron colliders is calculated to order $\alpha_s$ for general $C$ and $P$ conserving $WWZ$ couplings. The effects of the next-to-leading-order corrections on the derived sensitivity limits for…
We study the prospects of probing large extra dimension model at the LHC through neutral triple gauge boson production processes. In theories with extra dimensions these processes result from the exchange of a tower of massive graviton…
In this paper, triple neutral electroweak gauge boson production processes, viz. \gamma\gamma\gamma, \gamma\gamma Z, \gamma ZZ and ZZZ productions merged to 1-jet have been studied at the leading order in QCD in the context of…
Single $W$-boson production in $e^-\gamma$ collisions with polarized beams is investigated. Helicity amplitudes for general couplings are derived and their properties are discussed. The results are applied to the Standard Model (SM) and the…
We present the one-loop helicity amplitudes for processes involving a vector boson V (V=W,Z, or gamma^*) and four massless quarks, 0 to V q-bar q Q-bar Q, where V couples to a massless lepton pair. These amplitudes are required for…
The $W$-boson pair production in $e^-e^-$ collisions with polarized beams is investigated. The helicity amplitudes are derived for general couplings and the conditions for a good high-energy behaviour of the cross-section are given. The…
The self-couplings of the electroweak gauge bosons are probed at hadron colliders through the production of a massive gauge boson and a photon. To extend the theoretical description of this type of final states towards…
The Standard Model contributions to the processes $\gamma \gamma \to \gamma \gamma$, $\gamma Z$ and ZZ at sufficiently high energies, are found to be helicity conserving and almost purely imaginary. This is due to the W-loop contribution,…
The production of multiple gauge bosons via weak boson fusion is an important process at the LHC. It is relevant as a background process appearing in many searches and measurements, but also serves as a signal process when studying…
Delicate cancellations among diagrams can result in the vanishing of threshold amplitudes in the standard model. This phenomenon is investigated for multi-Higgs production by scalar, vector, and fermionic fields. A surprising gap is found…
We present calculations of cross sections for single $W^-$ and $Z$ production and $W^-W^-, W^-Z, W^-\gamma, ZZ$, and $W^+W^-$ pair production within the Standard Model at $e^-e^-$ linear colliders. We evaluate Standard-Model Higgs boson…
$\gamma\gamma\to\gamma Z$ scattering at the Photon Linear Collider is considered. Explicit formulas for helicity amplitudes due to $W$ boson loops are presented. It is shown that the $Z\gamma$ pair production will be easily observable at…
We investigate the electroweak process $qq\to qqW$, {\it i.e.} $W$ production via $W\gamma$ and $WZ$ fusion, as a probe for nonstandard $WW\gamma$ and $WWZ$ vertices at hadron supercolliders. Triggering on events with one very forward and…
We illustrate the effects of one-loop weak corrections onto the production of neutral gauge bosons of the Standard Model at RHIC-Spin, Tevatron and LHC, in presence of quark/gluon radiation from the initial state. We find such effects to be…