No abstract

In this note we summarize the status of the standard SANC modules (in the EW and QCD sectors of the Neutral Current branch -version 1.21 and the Charged Current branch -version 1.20). All versions of the codes are accessible from the SANC project servers at Dubna http://sanc.jinr.ru and CERN http://pcphsanc.cern.ch.

No abstract

The QCD sector of the system SANC is presented. QCD theoretical predictions for several processes of high energy interactions of fundamental particles at the one-loop precision level for up to some 3-and 4-particle processes are implemented. Root SANC QEDEW QCD Precomputation Processes 3 legs t −> W b b2q 4 legs Neutral Current Charged Current t −> b l nu t −> b l nu (FF) t −> b l nu (HA) t −> b l nu (BR) f1 f1' −> f fFigure 1: QCD part of the SANC tree.The structure of these branches is the same as the corresponding structure in the EW sector of SANC. For each process there are three FORM modules: (FF) Form Factor, (HA) Helicity Amplitudes, and (BR) Bremsstrahlung.Once the three FORM codes for the calculation of (FF), (HA) and (BR) have been compiled and outputs transferred to the software package s2n.f, one can get the numerical results. The user guide for running SANC is given in Ref. [1].We convolute the partonic sub-process cross section with quark density functions to get the cross section at the hadronic level. One must avoid double counting of the quark mass singularities, subtracting them from the density functions.SANC version v1.00 is accessible from servers at Dubna http://sanc.jinr.ru / (159.93.74.10) and CERN http://pcphsanc.cern.ch/ (137.138.180.42). QCD environmentThe QCD environment of SANC is a set of FORM procedures relevant for QCD. The basic procedure is QCDAlgebra.prc, which calculates color weights for process diagrams. It uses some common relations for T a matrices and structure constants f abc . We have changed several intrinsic SANC procedures like FeynmanRules.prc, MakeAmpSquare.prc, Trace.prc

NLO QCD corrections to charged and neutral current Drell-Yan processes and their implementation in the computer system SANC are considered. On the partonic level both quark-antiquark and quark-gluon scattering channels are taken into account. Subtractions of the collinear singularities in the massive case are compared with ones in the MS-bar scheme. Results of SANC on the hadronic level are presented. Comparison with results of the MCFM package is shown.Comment: 16 pages, 2 figure