CERN fails to confirm Fermilab tetraquark discovery-why?

[Fred Wright]

CERN recently announced (http://cds.cern.ch/record/2140095/) a null result for the X(5568) tetraquark which Fermilab has announced (http://arxiv.org/abs/1602.07588) it discovered with a statistical significance of 5.1sigma. This is very disturbing to me. Why is this? I am not an expert on particle physics but at first sight the only difference between the two experiments appears to be that the Fermilab collision experiment involved protons and antiprotons and the CERN experiment was pp collisions. What's up at CERN? Is the Fermilab data bogus? Could it be that X(5568) only comes forth in proton-antiproton collisions?

 

[JorisL]

What I got from this previous topic is that the data analysis was "off".

Its already in the first reply.

 

[mfb]

The Tevatron got shut down several years ago, and such an analysis is typically something you make within a year or two after data-taking. I guess they had that unexplained peak with the poor analysis for a while, and couldn't decide whether to publish it or not. Looks like "publish it" won now. Bad decision. See the previous thread for physics.

If the LHC energy was similar to the Tevatron energy, there would be models with exotic heavy particles that could explain such a difference, but the much higher energy of the LHC rules out all those models. The LHC has more sea antiquarks than Tevatron had valence antiquarks.

 

[Fred Wright]

Dear mfb, Thank you for taking the time to comment on my questions. It is illuminating and much appreciated.

 

[websterling]

I found an article about the lack of confirmation that stated the particle "was not seen in proton-proton collisions at the LHC."

I can't think of a reason why, but is it possible that the particle could only manifest itself in proton-antiproton collisions and not proton-proton collisions?

 

[mfb]

See the second part of my previous post. There is no reasonable model that would allow that.