SMATASY - A program for the model independent description of the Z resonance

SMATASY is an interface for the ZFITTER package and may be used for the model independent description of the Z resonance at LEP 1 and SLC. It allows the determination of the Z mass and width and its resonance shape parameters r and j for cross-sections and their asymmetries. The r describes the peak height and j the interference of the Z resonance with photon exchange in each scattering channel and for $\sigma_T$, $\sigma_{FB}$, $\sigma_{lr}$, $\sigma_{pol}$ etc. separately. Alternatively, the helicity amplitudes for a given scattering channel may be determined. We compare our formalism with other model independent approaches. The model independent treatment of QED corrections in SMATASY is applicable also far away from the Z peak.Comment: 25 pages (LaTeX), 5 figures, 1 table, see also http://www-zeuthen.desy.de/~riemann/ or http://hpl3sn02.cern.ch/homepages/gruenew

Four fermion final states in e+e−e^+e^- annihilation

The present status of calculations of four fermion final states is reviewed. Higher order problems arising there are pointed out. Special attention is paid to results obtained in the semi-analytical approach and their limitations and perspectives.Comment: 10 pages latex, uses nuclphys.sty (included), 1 figure included by epsf.sty, invited talk held at ``QED and QCD at higher orders'', Rheinsberg, April 199

Off shell W pair production in e+ e- annihilation: The CC11 process

The various four-fermion production channels in $e^+ e^-$ annihilation are discussed and the {\tt CC11} process $e^+ e^- \rightarrow {\bar f}_1^u f_1^d f^u_2 {\bar f}_2^d$, {\mbox{$f$$\neq$$e$}}, is studied in detail. The cross section $d^2\sigma/ds_1ds_2$, with $s_1,s_2$ being the invariant masses squared of the two fermion pairs, may be expressed by six generic functions. All but one may be found in the literature. The cross section, including initial state radiation and the Coulomb correction, is discussed and compared with other calculations from low energies up to $\sqrt{s}$ = 2 ~TeV.Comment: 28 pages, LaTex, 6 figures, 8 tables, a uuencoded file containing the latex file and figures is available via anonymous ftp at ftp://ftp.ifh.de/pub/preprint/desy95-167.uu and the complete ps file also from http://www.ifh.de/~riemann/desy95-167.ps.g

12 Years of Precision Calculations for LEP. What's Next?

I shortly review time period of twelve years, 1989-2000, which was devoted to a theoretical support of experiments at LEP and SLC at Z resonance and discuss several directions of possible future work in the field of precision theoretical calculations for experiments at future colliders.Comment: 11 Latex, including 1 figures. Updated version as appeared in the Journa

Project {\tt SANC} (former {\tt CalcPHEP}): Support of Analytic and Numeric calculations for experiments at Colliders

The project, aimed at the theoretical support of experiments at modern and future accelerators -- TEVATRON, LHC, electron Linear Colliders (TESLA, NLC, CLIC) and muon factories, is presented. Within this project a four-level computer system is being created, which must automatically calculate, at the one-loop precision level the pseudo- and realistic observables (decay rates and event distributions) for more and more complicated processes of elementary particle interaction, using the principle of knowledge storing. It was already used for a recalculation of the EW radiative corrections for Atomic Parity Violation [1] and complete one-loop corrections for the process $e^+ e^-\to t\bar{t}$ [2-4]; for the latter an, agreement up to 11 digits with FeynArts and the other results is found. The version of {\tt SANC} that we describe here is capable of automatically computing the decay rates and the distributions for the decays $Z(H,W)\to f\bar{f}$ in the one-loop approximation.Comment: 3 Latex, Presented at ICHEP2002, Amsterdam, July 24-30, 2000; Submitted to Proceeding

ZFITTER v.6.21 - A Semi-Analytical Program for Fermion Pair Production in e+e- Annihilation

We describe ZFITTER, a Fortran program based on a semi-analytical approach to fermion pair production in e+e- annihilation at a wide range of centre-of-mass energies, including the PETRA, TRISTAN, LEP1/SLC, and LEP2 energies. A flexible treatment of complete O(alpha) QED corrections and of some higher order contributions is made possible with three calculational chains containing different realistic sets of restrictions in the photon phase space. Numerical integrations are at most one-dimensional. Complete O(alpha) weak loop corrections supplemented by selected higher-order terms may be included. The program calculates Delta r, the Z width, differential cross-sections, total cross-sections, integrated forward-backward asymmetries, left-right asymmetries, and for tau pair production also final-state polarization effects. Various interfaces allow fits to be performed with different sets of free parameters.Comment: 200 pages, Latex2e, 26 figures, 4 tables; uses axodraw, epsfig, epsf, graphicx, espcrc1; typos of v.1 corrected, version for subm. to Comp. Phys. Commu

The American National Exhibition and Kitchen Debates: How the World\u27s Superpowers Portrayed the Events of the Summer of 1959 to Meet National Needs

An undergraduate research paper centered on the investigation of American and Soviet propaganda efforts during and immediately after the Kitchen Debate of 1959

Predictions for Fermion Pair Production at e+e- Colliders

We discuss the status and some ongoing upgrades of the ZFITTER program for applications at e+e- colliders LEP1/SLC, LEP2, GigaZ, and TESLA. The inclusion of top quark pair production is under work.Comment: 10 pages, 1 table, 2 figures, uses npb.sty, to appear in the proceedings of Zeuthen Workshop: Loops and Legs in Quantum Field Theory, 9-14 April, Bastei, German

ZFITTER: a semi-analytical program for fermion pair production in e+e- annihilation, from version 6.21 to version 6.42

ZFITTER is a Fortran program for the calculation of fermion pair production and radiative corrections at high energy e+e- colliders; it is also suitable for other applications where electroweak radiative corrections appear. ZFITTER is based on a semi-analytical approach to the calculation of radiative corrections in the Standard Model. We present a summary of new features of the ZFITTER program version 6.42 compared to version 6.21. The most important additions are: (i) some higher-order QED corrections to fermion pair production, (ii) electroweak one-loop corrections to atomic parity violation, (iii) electroweak one-loop corrections to nu-e nu-e-bar production, (iv) electroweak two-loop corrections to the W boson mass and the effective weak mixing angle.Comment: 60 pages, latex, 3 table