# Have Scientists Found Two Different Higgs Bosons?

1. Dec 17, 2012

### Staff: Mentor

From here: http://blogs.scientificamerican.com...-scientists-found-two-different-higgs-bosons/

So how significant would this be if it turns out to be true? I wasn't aware that there had been predictions of more than one Higgs in the first place, but the article says there was.

Also:

What's the significance of this? I don't know much about particle decay.

2. Dec 17, 2012

### K^2

Could one of these simply be a high energy resonance of one of the mesons? I'm not sure there would be any way to tell what they are detecting from, say, $\small \pi^0$. Of course, if one of these is just a meson resonance, then who's to say the other one isn't also?

Besides energy and $\small 2\gamma$ mode, what are they using to verify that it's actually a Higgs Boson? If somebody has a reference to an actual article, I'd appretiate it.

3. Dec 18, 2012

### Bill_K

The universal belief is that this is just an experimental difficulty. ATLAS sees it, but the other group CMS does not. See the Resonaances blog for a good discussion.

4. Dec 18, 2012

### Vanadium 50

Staff Emeritus
This is shamefully inaccurate blogging. The experiments are not claiming two peaks. It's all noise from the blogosphere.

5. Dec 18, 2012

### Bill_K

V50, I hope you're not knocking the Resonaances blog, which is accurate and well-informed, and IMO one of the top five sources of particle information on the web. He makes clear, I think, that the "two peaks" are the best fits in different channels, 123.5 GeV for the ZZ channel and 126.6 for γγ, undoubtedly due to a calibration error.

6. Dec 18, 2012

### ofirg

The statistical significance of this difference is only 2.7$\sigma$, so it could also be mainly a statistical fluctuation (maybe with a little push from a small calibration error)

7. Dec 18, 2012

### Staff: Mentor

I particularly like Resonaances third possible cause for the ATLAS problem, speaking of reliable reporting. The one involving ethanol.

8. Dec 18, 2012

### Staff: Mentor

To quote the ATLAS conference note:
Nothing serious, just bad luck or a calibration problem.

@K^2: Other decay channels, their branching fractions (which agree very well with the SM) and the angular distribution to determine its spin (which indicates spin 0).

9. Dec 18, 2012

### George Jones

Staff Emeritus
The Scientific American blog linked in the original post was guilty of "shamefully inaccurate blogging." According to Matt Strassler, this blog entry has been rewritten somewhat,

http://profmattstrassler.com/2012/12/17/two-higgs-bosons-no-evidence-for-that/.

10. Dec 18, 2012

### K^2

That certainly makes sense. I've found some theory papers on the decay modes, so I can now sit down and sort through it. Experimental papers ever only make my teeth hurt.

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook