Monday, May 19, 2014

Higgs Physics News

* The total decay width of the Higgs boson is constrained experimentally to be not more than 4.2 times the Standard Model Higgs boson expectation of 4.15 MeV for a 126 GeV mass Standard Model Higgs boson.

* New experiments by the CMS experiment at the LHC rule out a heavy Higgs boson in most of the mass range from 200 GeV to 1 TeV.
A SM-like Higgs boson is excluded in the mass range 248-930 GeV at 95% CL using the shape-based analysis. . . . For the less sensitive cut-and-count analysis we obtain an observed exclusion of 268-756 GeV[.]
SUSY Models and a variety of more conservative Standard Model extensions with additional Higgs bosons predict the existence of additional heavy, Standard Model-like Higgs bosons.

These results force these extensions to assume that the extra Higgs boson is nearly degenerate in mass with the observed one, or is in excess of 1 TeV which rules out much of the "natural" parameter space of SUSY models.

* A search for sub-eV scalar fields (similar in character to the Higgs boson field which has a 246 GeV scalar field, and which could be attributed to a second light Higgs boson or a inflation or dark energy field) has come up empty and placed stiff experimental constraints on this possibility.

1 comment:

andrew said...

The first preprint appears to be a formal write up of this story.