Experiment Suggests New Particle

[Kevin_Axion]

(PhysOrg.com) -- The results of a high-profile Fermilab physics experiment involving a University of Michigan professor appear to confirm strange 20-year-old findings that poke holes in the standard model, suggesting the existence of a new elementary particle: a fourth flavor of neutrino.

http://www.physorg.com/news/2010-11-physics-particle.html

The Standard Model clearly needs some remodeling, finally hope that I will have job opportunities in the future!

 

[arivero]

The Standard Model clearly needs some remodeling, finally hope that I will have job opportunities in the future!

Critical times are arriving, and our phenomenologists and model builders are going to be caught off-guard.

 

[bcrowell]

In this earlier paper, http://arxiv.org/abs/0704.1500 , they say that they have too many mu-neutrinos turning into e-neutrinos if there are only three flavors. Why would more flavors cause more mu->e changes? I would think that if there were more flavors, you'd end up with less of each flavor, because there are more things to turn into.

 

[granpa]

http://www.physorg.com/news/2010-11-physics-particle.html

the fact that the MiniBooNE experiments produced different results for antineutrinos than for neutrinos especially astounds physicists.

"The fact that we see this effect in antineutrinos and not in neutrinos makes it even more strange,"

 

[Vanadium 50]

I hate to rain on everyone's parade, but this is being driven by a press release from the University of Michigan, and not by the experiment itself. It makes me want to toss around words like "irresponsible", but let's stick to the facts - the miniBoone experiment itself is not suggesting that they have discovered a new particle.

The history: The LSND experiment ran in the 1990's and measured neutrino oscillations for antineutrinos that were inconsistent with solar and atmospheric neutrino oscillations. This result was controversial, even within LSND (a breakway group inside the experiment published their own paper challenging the results). They later switched to neutrinos and measured a number that was consistent with antineutrinos.

Then the miniBoone experiment ran, and was inconsistent with LSND for neutrinos. Later (a few months ago), they published their smaller antineutrino data set, which is consistent with LSND but also (barely) consistent with no oscillation: they see an excess of 20 +/- 14 events.

While interesting, I think this is way, way premature to announce the discovery of a sterile neutrino, or discovery of CPT violation. Apparently the University of Michigan press office disagrees.

 

[Ash Small]

i think it's a bit early to read too much into this, although they seem to have produced the same results for anti-neutrinos as Los Alamos obtained.

This article from last year proves they don't always get it right, in fact they made some pretty basic blunders here.

http://www.physorg.com/news165500651.html

Condidering the Solar Neutrino Problem as well, (which asks why we can only detect a third of the number of neutrinos from the sun than we would expect, suggesting that only a third of the energy radiated by the sun comes from fusion) there are some answers required. Are they suggesting that the other (previously unaccounted for) two thirds of solar neutrinos are this fouth, undetectable, flavour?

 

[arivero]

which is consistent with LSND but also (barely) consistent with no oscillation: they see an excess of 20 +/- 14 events.

How in the hell do they construe a 3-sigma from 20 +/- 14?

 

[Vanadium 50]

Very asymmetric uncertainties.

 

[arivero]

By the way, I had forgotten, but I had a candidate particle for LSND experiment. It is the superpartner of a pair of electrically charged scalars. Hmm, thus, actually, it is not a neutrino, so should it be called the LSD experiment?