A direct Measurement of the W Boson Width in ppbar Collisions at sqrt(s) = 1.96 TeV

TL;DR

This paper reports a direct measurement of the W boson decay width using proton-antiproton collision data at 1.96 TeV, achieving results consistent with the Standard Model predictions.

Contribution

The study provides a novel direct measurement of the W boson width using a large dataset and a specific fitting method, improving precision over previous indirect estimates.

Findings

Measured W boson width: 2032 +/- 45 (stat) +/- 57 (syst) MeV

Results are consistent with Standard Model expectations

Used 350 pb-1 of data from Fermilab Tevatron

Abstract

A direct measurement of the total decay width of the W boson G_W is presented using 350 pb-1 of data from ppbar collisions at sqrt(s) = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The width is determined by normalizing predicted signal and background distributions to 230185 W candidates decaying to enu and munu in the transverse-mass region 50 < M_T < 90 GeV and then fitting the predicted shape to 6055 events in the high-M_T region, 90 < M_T < 200 GeV. The result is G_W = 2032 +/- 45 (stat.) +/- 57 (syst.) MeV, consistent with the standard model expectation.