Sergio Cacciatori 2009

W mass workshop

Second meeting, Fermilab, October 4-5 2010

First meeting (Milano, March 17th-18th, 2009)

Scientific program    Participants    Practical information   Organizers

The large amount of high quality data collected by CDF and D0 at the Tevatron has pushed the measurement of the W mass(width) to an accuracy at the 0.03 (2.2) % level, and further improvements are anticipated at the LHC. At this level of accuracy, the challenging task of determining the systematic error requires a careful consideration of all aspects of the data analysis, including the treatment of higher-order corrections.

In view of a 25 MeV measurement of the W mass, it becomes increasingly important to control the theoretical predictions and to fully understand the present theoretical uncertainties. A lot of progress has been made in both the QCD and the EW sector. However, the predictions including QCD and EW radiative corrections are not available in one event generator: therefore the need for developing recipes which allow to combine the different sets of radiative corrections. The uncertainties intrinsic for these recipes should be quantified in a systematic way.

The aim of this meeting is to have extensive discussion sessions where:

i) the authors of the NLO event generators (HORACE, RESBOS, W/ZGRAD, SANC, MC@NLO, FEWZ, ...) can discuss theoretical uncertainties, limitations of their codes, possible improvements, plans/recipes for combining with or interfacing to different codes;

ii) the experimentalists involved in the W-mass and W-width measurements can present and discuss the challenges in the analysis with emphasis on the theory input, and communicate the necessary improvements in the available codes.

Useful documents

Preliminary draft of the final report

Routines (C++ and Fortran) for the recombination of leptons and photons

Setup for the comparisons of the different codes

Comment by Pavel Nadolsky on MRST2004QED

List of points to be discussed


John Campbell (Fermilab)

Ashutosh Kotwal (Duke)

Jan Stark (Grenoble)

Alessandro Vicini (Milano)

Doreen Wackeroth (SUNY at Buffalo)