Higgs at the Tevatron

posted by @ulaulaman about #higgs #physics #tevatron

This is the week of the Higgs. Indeed, wednesday, at CERN, ATLAS and CMS announced the results of the elaboration of the data collected in the first part of 2012... and a lot of journalists write about the probable discover of the Higgs boson. Indeed the two collaborations are disegned in order to discover the boson related to the mechanism that provides the mass to the other particles. Waiting for the conference, today CDF and DZero, the two collaborations of Tevatron, publicize in two conferences the first elaboration of the complete set of data about Higgs research. Their result was summarize by the following plot:

In the image there is the combination of the final results from the two collaborations. The two experiments combined detecte an excess in signals around 125 GeV with a 2.5 sigma. It is not the discover of the Higgs boson, but it could be a good clue for the existence of the boson. So I don't know if ATLAS and CMS will confirm or update this result in their next conferences, but in every case I must remmber to the readers that with a mass of 125 GeV we have need of physics beyond Standard Model, because the only SM is not sufficient to explain our universe. In order to explain better, I reprint here some considerations that I just published for the previous Higgs day:

Higgs' research: CDF and D0 confirm ATLAS and CMS results

Do you remember the conference of ATLAS and CMS about their Higgs' preliminary results? Well. Today during Moriond 2012 conference, the two Tevatron's collaboration, CDF and D0, presented their results about Higgs research:

(the plot shows the upper limit on the Higgs boson production rate)

In synthesis they confirm LHC's results (Tevatron's Higgs range: 115 GeV - 135 GeV, with $sigma = 2.2$).
More details on: Fermi Lab's press release, Tommaso Dorigo, the source of the image.
Special thanks to Peppe Liberti.

A circle around Higgs boson

After the post about D0 abstracts, I return to write about Higgs boson after the last Fermilab's press release about the mass limit of Higgs boson. Combinig data from D0 and CDF, Tevatron's limits are 114-137 GeV/c². The results was presented last week in Grenoble at the EPS High-Energy Physics conference, that it will finish on the 27th July.
During the same conference also LHC's experiments presented their first results, analyzed in about one month! And the conclusion seems un-huppy for Tevatron: the Fermilab's particle accelerator has only one chance to find Higgs boson before LHC. Why? We can simply see the following plots presented by ATLAS and CMS (via Résonaances, Tommaso Dorigo):

The two european experiments presented only a little region around 115 GeV/c², the Tevatron's region, to 140 GeV/c². The data from this region are probably analized and published before the end of the year, so we must wait only some months to know if Tevatron could found Higgs or not⁽¹⁾.
Tomasso examined in details some CMS preprint in which they are studied a lot of Higgs production channels, and also Philip Gibbs write a great summary about LHC presentations, who realize a great conclusion plot:

D0 abstracts: Higgs limits and dimuon asymmetry

I usually publish abstract's digests on posterous, but in this case I think this is necessary an exception. D0 collaboration at Tevatron, indeed, released two papers on arxiv, and I think that it is important sharing with the much number of readers their work. I startwith Search for neutral Higgs bosons decaying to $\tau$ pairs produced in association with $b$ quarks in $p \bar{p}$ collisions at $\sqrt s = 1.96$ TeV, shared by Tommaso:

We report results from a search for neutral Higgs bosons produced in association with b quarks using data recorded by the D0 experiment at the Fermilab Tevatron Collider and corresponding to an integrated luminosity of 7.3 $fb^{-1}$. This production mode can be enhanced in several extensions of the standard model (SM) such as in its minimal supersymmetric extension (MSSM) at high tanBeta. We search for Higgs bosons decaying to tau pairs with one tau decaying to a muon and neutrinos and the other to hadrons. The data are found to be consistent with SM expectations, and we set upper limits on the cross section times branching ratio in the Higgs boson mass range from 90 to 320 $GeV/c^2$. We interpret our result in the MSSM parameter space, excluding tanBeta values down to 25 for Higgs boson masses below 170 $GeV/c^2$.

The other two papers are in Antimatter Tevatron mystery gains ground, a great BBC's article. In particular BBC writes about Measurement of the anomalous like-sign dimuon charge asymmetry with 9 $fb^{-1}$ of $p \bar{p}$ collisions: