Z boson as “the standard candle” for high-precision W -boson physics at LHC

In this paper we propose a strategy for measuring the inclusive W -boson production processes at LHC. This strategy exploits simultaneously the unique flexibility of the LHC collider in running variable beam particle species at variable beam energies, and the configuration flexibility of the LHC detectors. We propose their concrete settings for a precision measurement of the Standard Model parameters. These dedicated settings optimise the use of the Z boson and Drell–Yan-pair production processes as “the standard reference candles”. The presented strategy allows to factorise and to directly measure those of the QCD effects which affect differently the W and Z production processes. It reduces to a level of O(10−4) the impact of uncertainties in the partonic distribution functions (PDFs) and in the transverse momentum of the quarks on the measurement precision. Last but not the least, it reduces by a factor of 10 an impact of systematic measurement errors, such as the energy scale and the measurement resolution, on the W -boson production observables. To be submitted to the European Physical Journal C CERN-PH-TH/2007-041, TPJU-1/2007 February 2007 ⋆The work is partly supported by the program of co-operation between the IN2P3 and Polish Laboratories No. 05-116, and by the EU Marie Curie Research Training Network grant under the contract No. MRTN-CT-2006-035505.