New Tevatron average of top quark mass: 1.3% total error! March 20, 2006
Posted by dorigo in internet, physics, science.trackback
Tomorrow on Arxiv you will be able to read about the new combination of all measurements so far achieved of the top quark mass. Of course, the new determinations by CDF and D0 using 750 inverse picobarns of Run II data are bringing a whole new taste to this old game: the top quark mass is now known with 1.3% accuracy! That is breaking ground!
Hep-Ex/0603039 will be available starting tomorrow. Here is the title and abstract:
Combination of CDF and D0 results on the mass of the Top Quark
The Tevatron Electroweak Working Group for the CDF and D0 collaborations
Abstract
We summarize the top-quark mass measurements from the CDF and D0 experiments at Fermilab. We combine published Run-I (1992-1996) measurements with the most recent preliminary Run-II (2001-present) measurements using up to 750 pb-1 of data. Taking correlated uncertainties properly into account the resulting preliminary world average mass of the top quark is Mt=172.5 +- 1.3(stat) +- 1.9(syst) GeV/c2, which corresponds to a total uncertainty of 2.3 GeV/c2. The top-quark mass is now known with a precision of 1.3% – a 20% improvement relative to the previous combination.
[...] Via Tommaso Dorigo of the CDF collaboration, the news that the Tevatron Electroweak Working Group has released a new analysis of combined CDF and D0 data with the most accurate result so far for the top quark mass: 172.5 +/- 2.3 Gev. Last summer this value was at 174.3 +/- 3.4 Gev (see a posting here), an improvement over the earlier value derived just using Run I data of 178.0 +/- 4.3 Gev. [...]
I was just thinking, given the current precision of Fermi constant, should you experimentalists try to quote the yukawa coupling of top (hmm, 0.991 +- 0.013?) instead of or at the same time that the measured mass in GeV? I understand it is trublesome because it is a model-dependent quantity, but I am starting to be tired of hearing “of order unity” as if it were 7.43 or 0.21 or 1.89.
Hi Alejandro,
this looks like a good idea… I will bring it to the next collaboration meeting.