Has the Higgs Boson Particle Been Discovered at Cern?

[eXorikos]

That I know, but why does unitarity not prove the impossibility of a fourth generation?

If the CKM matrix is unitary, how can there be a fourth generation that mixes with the three known generations?

 

[mfb]

You always have measurement uncertainties - while the measurements can be consistent with (3x3) unitarity, they cannot prove it. The other option would be no mixing with the 4th generation at all, but that looks odd.

If mixing with a 4th generation exists, it has to be small, otherwise it would have been detected in loops (similar to the top-quark). And the high required neutrino mass is extremely odd, given that the known three neutrinos have a mass of at most 1-2 eV (using the upper limit for the electron neutrino and the mixing measurements).

 

[PAllen]

References to the following paper are beginning to make the rounds, so thought I'd post here (though all differences from SM in the recent LHC data are 2 sigma or less, of course people will jump on the hints):

http://arxiv.org/abs/1207.1445

 

[tom.stoer]

... but why does unitarity not prove the impossibility of a fourth generation?

If the CKM matrix is unitary, how can there be a fourth generation that mixes with the three known generations?

As said: "It doesn't, and indeed, it cannot. Non-unitarity of the 3x3 CKM can require a 4th generation, but unitarity cannot forbid one."

If the 3*3 CKM matrix is not unitary this may (or must?) be fixed by adding a forth generation. If the 3*3 CKM matrix is unitary there may be a forth generation w/o CKM mixing. I am not even sure whether a 'putative unitary' 3*3 CKM matrix with experimental uncertainties taken into account does rule out a small 4*4 mixing.

EDIT: just saw mfb's reply ...

 

[PhysicsPimpin]

Super-symmetry Credence By This?

Hey, if the mass magnitude of the Higgs is reveal able at the Cern accelerator energies, does that not give some hope as to giving String Theories main hypothesis of Super symmetric partner predictions a possible testing scenario for 11-Dimensional Prerequisite String Theory Modeling using scientific methods for verification?

I would love to see the quantum gravitational solution to Einsteins life work and the Standard Model.

I think that may be the (what kind of box you ain't supposed to open?) key yo.

 

[mfb]

Searches for SUSY (=supersymmetry) particles are a big part of the physics analyses done with the ATLAS and CMS detectors.
So far, none were found. We'll see what happens in 2015 with the increased energy.

 

[Shin204]

We hear people talking about the "party model" of the Higgs boson, but what made that particle so popular in the first place? In a technical question:What makes matter interact with the higgs in the first place?

 

[mfb]

We hear people talking about the "party model" of the Higgs boson, but what made that particle so popular in the first place?

According to Boston Globe:

The celebrity analogy, for instance, was first concocted in 1993 by David Miller, a physicist at University College London. Miller submitted it as one of the winning entries to a challenge posed by UK Science Minister William Waldegrave: On one sheet of paper, explain what the Higgs boson is and why it’s important to find it.

In a technical question:What makes matter interact with the higgs in the first place?

There is no known deeper reason why things interact. We just observe those interactione and can describe them with formulas.

 

[ChrisVer]

Additionally to mfb's P#183 and why the matter interacts with Higgs:
They interact because they are allowed by the current symmetries... If some interaction terms are allowed by your theory's symmetries, then you have to take them into account. If these interactions happen not to exist, one can postulate additional symmetries to set the coupling constants to zero (so that you won't have naturalness problems - coupling constants extremely small). And although the general symmetry allows those terms, the extra one is going to kill them.

 

[euclideanspace]

Higgs may still be controversial..

http://www.dailymail.co.uk/sciencetech/article-2171611/Is-God-particle-impostor-Scientists-claim-signal-Large-Hadron-Collider-Higgs-all.html

 

[ChrisVer]

http://cms.web.cern.ch/sites/cms.we...public/field/image/image1_1.png?itok=fibts9L4

http://www.atlas.ch/news/images/stories/1-plot.jpg

Here are the graphs which showed the Higgs discovery from CMS and ATLAS. It's the graphs which made those two organizations to publish the papers in which they claimed to have found a new particle. From an experimental point of view, these results only need better statistical corrections which will be available by the time LHC starts operating again. It is a common knowledge however, and after further studies, that the new particle is indeed the Higgs and we only need time to pile up more data to get better sigmas.

 

[mfb]

Higgs may still be controversial..

http://www.dailymail.co.uk/sciencetech/article-2171611/Is-God-particle-impostor-Scientists-claim-signal-Large-Hadron-Collider-Higgs-all.html

This article is from 2012, one week after the discovery of the particle got announced. It is completely outdated.

It is uncontroversial that ATLAS and CMS found "a" Higgs boson. There might be more (but nothing else has been found so far), but the new particle is clearly a Higgs boson.

New results indicate that new particle is a Higgs boson (March 2013)
The birth of a Higgs boson (May 2013 - it is simply called "Higgs boson" since then).

 

[ChrisVer]

additionally again, it's a Standard Model Higgs (un)fortunately...without making clear whether there is any more extra physics beyond it or not... leaving us only with the chance of finding a 2nd one or not to make sure. Am I the only one who finds this irritating? Out of so much free region, for it to go and "stand" right between the MSSM and SM limits...
http://indico.cern.ch/event/186656/session/0/contribution/4/material/slides/0.pdf

 

[Superposed_Cat]

There is a thread like this every week, just see one of the other 100 duplicates, damn. seriously someone give me a week we went without a "higgs particle found?" In the high energy and nuclear physics section. Not a rhetorical question.

 

[mfb]

The last post in this thread was in July 2014.

 

[Superposed_Cat]

was in front page, many apologies. Must have been made a sticky for that reason.

 

[mfb]

It is sticky for exactly that reason.