New Higgs predictions from EW fits: M(h)=80 GeV! January 19, 2007Posted by dorigo in news, physics, science.
An improved version of the Mw-Mt plot has been produced for winter conferences. I am still unaware of the numbers entering in this new global fit, but here is the January 2007 result anyhow: the most likely higgs mass sits at 80 GeV, with an uncertainty of +36-26 GeV. This supersedes the former result of 85+39-28 GeV.
The plot shows the dependence between the W mass and the top quark mass in the Standard Model, as a function of the unknown mass of the Higgs. Lines belonging to the green band represent the functional dependence between W and top mass for a fixed value of Higgs mass. The red ellipse constrains the three particle masses using electroweak measurements at LEP and SLD, while the blue ellipse encrypts all direct measurements of the top and W masses. The fact that the intersection between the blue ellipse and the red one is very small, and does not include any green region, implies that there is a tension between the lower limit on the Higgs mass obtained at LEP II (114 GeV) and the favored higgs mass, now at 80 GeV and thus about one sigma away from the allowed region.
This is becoming a story of the incredibly shrinking higgs. But wait until my team blesses an improved jet energy scale measurement in CDF, using the Z->bb peak: I expect it to change things a bit, since most of CDF top quark mass determinations will be affected. If the authors of the analyses include the new scale measurement into their results, that is.