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How do I like my Mw – Mt plot January 7, 2007

Posted by dorigo in personal, physics, science.

A further note about the plot I posted a few days ago, attached here again for convenience. For the series “the devil hides in the details”… I am such a pain in the neck when it comes to proper display of scientific data, I realize. But I cannot help it.

So. The more I look at this plot, the less I like it.

First of all, it is wrong.  The CDF measurement is at 80413 MeV, so the star in the middle of the black line should lie at around halfway between the 80.4 mark and the next one (80.425). But it is much lower than that: if you look at it closely, it seems to lie at about 80.406 or so. The same applies if you look at the extremes of the error bar: looks like 80.455 and 80.360 or so, while you’d expect 80.461 and 80.365. 

Another subtle point which disturbes me is that since the red ellipse shows indirect measurements by LEP I and SLD, and since LEP II measured the W mass but give no clue about the top mass, putting together LEP II and Tevatron determinations into one single ellipse (the blue one) is deceiving and unfair to the Tevatron.

Indeed, while the Tevatron experiments can draw an ellipse with direct determinations of both the W and top quark masses, the LEP II experiments can only draw a horizontal band in that plot.

So it would suit my taste better to have a plot with:

  • the odd-shaped ellipse of indirect measurements
  • a band combining all LEP II measurements of the W mass
  • an ellipse for Tevatron measurements of top and W masses
  • another ellipse, centered at the same top mass value as the former, with the world average of direct measurements
  • a bar with the latest (not yet averaged) Run II CDF W mass result.

All labeled up properly, please.

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