M. Skrzypek

Monte Carlo program KORALW 1.02 for W-pair production at LEP2NLC energies with Yennie-Frautschi-Suura exponentiation

Abstract The Monte Carlo program KORALW version 1.02 for W-pair production is presented. Its main features are: multiple initial state photonic radiation with finite transverse photon momenta generated according to the Yennie-Frautschi-Suura Monte Carlo technique and massive kinematics for all final particles. Matrix element features second-order leading-logarithmic initial-state QED corrections. The dedicated semi-analytical program KORWAN, with structure-function based leading-logarithmic initial-state photonic radiation up to third order, is also included in the distribution package.

Initial state QED corrections to W-pair production at LEP2/NLC — Monte Carlo versus semi-analytical approach☆

Abstract We present a comparison of the Monte Carlo code KORALW with the SemiANalytical code KORWAN for W-pair production. We focus on the technical precision, total cross section and some differential distributions. We find the technical precision of KORALW in the LEP2 energy range to be of order 10−4 or better. We show that within the 0.1% precision level the O (α2) photonic corrections are not necessary in the YFS framework, at least for the total cross section. A detailed description of the semi-analytical formalism implemented in the KORWAN routine is also given.

Monte Carlo program KoralW 1.42 for all four-fermion final states in e+e− collisions*

Abstract The Monte Carlo program KoralW version 1.42 is presented. It generates all four-fermion final states with multibranch dedicated Monte Carlo presamplers and complete, massive, Born matrix elements. The presamplers cover the entire phase space. Multiphoton bremsstrahlung is implemented in the ISR approximation within the YFS formulation with the O (α 3 ) leading-log matrix element. The anomalous WWV couplings are implemented in CC03 approximation. The standard decay libraries (JETSET, PHOTOS, TAUOLA) are interfaced. The semi-analytical CC03-type code KorWan for differential and total cross sections is included.

The Monte Carlo event generator YFSWW3 version 1.16 for W-pair production and decay at LEP2/LC energies☆☆☆

Abstract We present the Monte Carlo event generator YFSWW3 version 1.16 for the process of W-pair production and decay in electron–positron collisions. It includes O (α) electroweak radiative corrections in the WW production stage together with the O (α 3 ) initial-state-radiation (ISR) corrections in the leading-logarithmic (LL) approximation, implemented within the Yennie–Frautschi–Suura (YFS) exclusive exponentiation framework. The photon radiation in the W decays is generated by the dedicated program PHOTOS up to O (α 2 ) LL, normalized to the W branching ratios. The program is interfaced with the τ decay library TAUOLA and the quark fragmentation/hadronization package JETSET . The semi-analytical code KorWan for the calculations of the differential and total cross-sections at the Born level and in the ISR approximation is included.

The Monte Carlo program KoralW version 1.51 and the concurrent Monte Carlo Koralw&YFSWW3 with all background graphs and first-order corrections to w-pair production

The version 1.51 of the Monte Carlo (MC) program KoralW for all e + e − ! f1 ¯ f2f3 ¯ f4 processes is presented. The most important change from the previous version 1.42 is the facility for writing MC events on the mass storage device and reprocessing them later on. In the reprocessing parameters of the Standard Model may be modified in order to fit them to experimental data. Another important new feature is the possibility of including complete O(α) corrections to doubleresonant W-pair component-processes in addition to all background (non-W W) graphs. The inclusion is done with the help of the YFSWW3 MC event generator for fully exclusive differential distributions (event per event). Technically, it is done in such a way that YFSWW3 runs concurrently with KoralW as a separate slave process, reading momenta of the MC event generated by KoralW and returning the correction weight to KoralW. The latter introduces the O(α) correction using this weight, and finishes processing the event (rejection due to total MC weight, hadronization, etc.). The communication between KoralW and YFSWW3 is done with the help of the FIFO facility of the UNIX/Linux operating system. This does not require any modifications of the FORTRAN source codes. From the user’s point of view, the resulting Concurrent MC event generator KoralW&YFSWW3 looks as a regular single MC event generator with all the standard features.

Gauge-invariant YFS exponentiation of (un)stable Z -pair production at and beyond CERN LEP 2 energies

We present the theoretical basis and sample Monte Carlo data for the YFS exponentiated calculation of

Final-state radiative effects for the exactO(α)Yennie-Frautschi-Suura exponentiated (un)stableW+W−production at and beyond CERN LEP2 energies

{e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{ZZ}\ensuremath{\rightarrow}{f}_{1}{\overline{f}}_{1}+{\overline{f}}_{2}{f}_{2}

Exact and approximate solutions for the electron nonsinglet structure function in QED

at and beyond CERN LEP 2 energies, where the left-handed part of

Is there a better way of exponentiating QED corrections

{f}_{i}

Precision predictions for (un)stable W + W − pair production at and beyond CERN LEP2 energies

is a component of an