Evidence for a new particle gets stronger

[n2doc]

By John Timmer | Published about 2 hours ago

It may have been a holiday weekend in the US and UK, but physics never takes the day off. A conference entitled Particle Physics and Cosmology took place in France, and featured a talk by Giovanni Punzi, a member of Fermilab's CDF collaboration. Although the talk primarily focused on the search for the Higgs boson at Fermi and CERN, he managed to slip in five slides on a result we discussed just a month ago: the prospect that the Tevatron has spotted a previously unknown particle with a mass of 150GeV. The slide makes clear that the CDF detector team has continued crunching its way through its data, and the case for a new particle has gotten stronger.

The results in April were produced by looking at events that produced a W boson and a pair of jets of lighter particles. After subtracting out all the other events that produce this sort of pattern, it's possible to see a peak in the data at the energy associated with W/W and W/Z production. But, just to the right of that, the authors saw a second peak, which suggested the possibility of a new particle being produced, one that has a mass that doesn't correspond to anything in the standard model.

The peak was a bit over three standard deviations away from where we'd expect the data to graph if nothing unusual was happening here. In physics, consensus has been that nothing has been discovered until we have data at five standard deviations, so the initial results were considered reason to pay attention, but nothing definitive. Fortunately, they became apparent when only a portion of the Tevatron data was analyzed; working with more of the data set should help clarify whether the peak is a statistical fluke.

According to Punzi, we're not at discovery yet, but we're getting tantalizingly close. The first results were generated using 4.3 inverse femtobarns of data; we're now up to 7.3fb-1, the peak is not going away, and the results are now closer to the five standard deviation standard. In addition, the detector team has gone back and eliminated some alternative explanations, like background from top quark production.

more
http://arstechnica.com/science/news/2011/05/evidence-for-a-new-particle-gets-stronger.ars

[GodlessBiker]

1. I don't know, it sounds like a Punzi scheme to me. ;-)

[ChairmanAgnostic]

3. May a pair of intertwined quarks empty their bowels on your head

For pun nishing us like that

[KansDem]

2. KnR

I find this "stuff" fascinating!!

[laconicsax]

4. Exciting stuff! n/t

[damntexdem]

5. So the evidence is particularly strong?

;-)

[Salviati]

8. definitely some strange stuff going on.

But I'd be willing to put money down that these top scientists will soon get to the bottom of it, and find out what's up.


Oh yeah, and charm too. :P

[phantom power]

6. kick for using the unit "inverse femtobarns"

:patriot:

[truedelphi]

7. My exact reason for kicking too. n/t

[sofa king]

9. I keep the sqare root of negative one horses in my inverse femtobarn.