Radiative corrections to e+e- --> WW --> 4f with RACOONWW

RACOONWW is the first Monte Carlo generator for e+e- --> WW --> 4f(+gamma) that includes the electroweak O(alpha) radiative corrections in the double-pole approximation completely. Some numerical results for LEP2 energies are discussed, and the predictions for the total W-pair cross section are confronted with LEP2 data.Comment: 7 pages, latex, 5 postscript files, to appear in the Proceedings of the 5th Zeuthen Workshop on Elementary Particle Theory ``Loops and Legs in Quantum Field Theory'', Bastei/Koenigstein, Germany, April 9-14, 200

Four-fermion production with RACOONWW

RACOONWW is an event generator for e+e- --> WW --> 4fermions(+gamma) that includes full tree-level predictions for e+e- --> 4f and e+e- --> 4f+gamma as well as O(alpha) corrections to e+e- --> 4f in the so-called double-pole approximation. We briefly sketch the concept of the calculation on which this generator is based and present some numerical results.Comment: 9 pages, latex, 6 postscript files, to appear in the proceedings of the UK Phenomenology Workshop on Collider Physics, Durham, UK, 19-24 September, 199

Electroweak Radiative Corrections to Off-Shell W-Pair Production

We briefly describe the RacoonWW approach to calculate radiative corrections to e+ e- -> W W -> 4 fermions and present numerical results for the total W-pair production cross section at LEP2.Comment: 3 pages, 2 figures, talk given at the DPF2000 meeting, Columbus, OH, August 9-12, 200

RacoonWW1.3: A Monte Carlo program for four-fermion production at e^+ e^- colliders

We present the Monte Carlo generator RacoonWW that computes cross sections to all processes e^+ e^- -> 4f and e^+ e^- -> 4f + gamma and calculates the complete O(alpha) electroweak radiative corrections to e^+ e^- -> W W -> 4f in the electroweak Standard Model in double-pole approximation. The calculation of the tree-level processes e^+ e^- -> 4f and e^+ e^- -> 4f + gamma is based on the full matrix elements for massless (polarized) fermions. When calculating radiative corrections to e^+ e^- -> W W -> 4f the complete virtual doubly-resonant electroweak corrections are included, i.e. the factorizable and non-factorizable virtual corrections in double-pole approximation, and the real corrections are based on the full matrix elements for e^+ e^- -> 4f + gamma. The matching of soft and collinear singularities between virtual and real corrections is done alternatively in two different ways, namely by using a subtraction method or by applying phase-space slicing. Higher-order initial-state photon radiation and naive QCD corrections are taken into account. RacoonWW also provides anomalous triple gauge-boson couplings for all processes e^+ e^- -> 4f and anomalous quartic gauge-boson couplings for all processes e^+ e^- -> 4f + gamma.Comment: 62 pages, LaTeX, elsart styl

Probing anomalous quartic gauge-boson couplings via e+e- --> 4fermions+gamma

All lowest-order amplitudes for e+e- --> 4f+gamma are calculated including five anomalous quartic gauge-boson couplings that are allowed by electromagnetic gauge invariance and the custodial SU(2)_c symmetry. Three of these anomalous couplings correspond to the operators L_0, L_c, and L_n that have been constrained by the LEP collaborations in WWgamma production. The anomalous couplings are incorporated in the Monte Carlo generator RACOONWW. Moreover, for the processes e+e- --> 4f+gamma RACOONWW is improved upon including leading universal electroweak corrections such as initial-state radiation. The discussion of numerical results illustrates the size of the leading corrections as well as the impact of the anomalous quartic couplings for LEP2 energies and at 500GeV.Comment: 27 pages, latex, 42 postscript files, some misprints correcte

W-pair production at future e+e- colliders: precise predictions from RACOONWW

We present numerical results for total cross sections and various distributions for e+e- --> WW --> 4f(+gamma) at a future 500GeV linear collider, obtained from the Monte Carlo generator RACOONWW. This generator is the first one that includes O(alpha) electroweak radiative corrections in the double-pole approximation completely. Owing to their large size the corrections are of great phenomenological importance.Comment: 11 pages, latex, 10 postscript file

Electroweak and QCD corrections to Higgs production via vector-boson fusion at the LHC

The radiative corrections of the strong and electroweak interactions are calculated at next-to-leading order for Higgs-boson production in the weak-boson-fusion channel at hadron colliders. Specifically, the calculation includes all weak-boson fusion and quark--antiquark annihilation diagrams to Higgs-boson production in association with two hard jets, including all corresponding interferences. The results on the QCD corrections confirm that previously made approximations of neglecting s-channel diagrams and interferences are well suited for predictions of Higgs production with dedicated vector-boson fusion cuts at the LHC. The electroweak corrections, which also include real corrections from incoming photons and leading heavy-Higgs-boson effects at two-loop order, are of the same size as the QCD corrections, viz. typically at the level of 5-10% for a Higgs-boson mass up to \sim 700 GeV. In general, both types of corrections do not simply rescale differential distributions, but induce distortions at the level of 10%. The discussed corrections have been implemented in a flexible Monte Carlo event generator.Comment: 33 pages, LaTeX, 24 postscript figure

Electroweak radiative corrections to e+e- --> WW --> 4fermions in double-pole approximation -- the RACOONWW approach

We calculate the complete O(alpha) electroweak radiative corrections to e+e- --> WW --> 4f in the electroweak Standard Model in the double-pole approximation. We give analytical results for the non-factorizable virtual corrections and express the factorizable virtual corrections in terms of the known corrections to on-shell W-pair production and W decay. The calculation of the bremsstrahlung corrections, i.e. the processes e+e- --> 4f+gamma in lowest order, is based on the full matrix elements. The matching of soft and collinear singularities between virtual and real corrections is done alternatively in two different ways, namely by using a subtraction method and by applying phase-space slicing. The O(alpha) corrections as well as higher-order initial-state photon radiation are implemented in the Monte Carlo generator RACOONWW. Numerical results of this program are presented for the W-pair-production cross section, angular and W-invariant-mass distributions at LEP2. We also discuss the intrinsic theoretical uncertainty of our approach.Comment: 51 pages, latex, 28 postscript file