CERN fails to confirm Fermilab tetraquark discovery-why?

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Discussion Overview

The discussion centers around the lack of confirmation by CERN of the Fermilab discovery of the X(5568) tetraquark. Participants explore the implications of differing experimental conditions between Fermilab's proton-antiproton collisions and CERN's proton-proton collisions, as well as the validity of the data analysis from Fermilab.

Discussion Character

  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants express concern over CERN's null result for the X(5568) tetraquark, questioning the validity of Fermilab's findings.
  • One participant suggests that the data analysis at Fermilab may have been flawed, indicating that the analysis was "off."
  • Another participant notes that the Tevatron's shutdown may have impacted the timing and quality of the analysis, implying that the decision to publish may have been premature.
  • Some participants propose that if the LHC energy is significantly higher than that of the Tevatron, it could rule out certain models that might explain the observed differences in particle detection.
  • There is speculation about whether the X(5568) could only be produced in proton-antiproton collisions, though one participant argues that no reasonable model supports this idea.

Areas of Agreement / Disagreement

Participants express differing views on the reliability of the Fermilab data and the implications of CERN's findings. There is no consensus on the reasons for the lack of confirmation or the validity of the experimental results.

Contextual Notes

Limitations include the potential for unresolved issues in data analysis and the dependence on specific experimental conditions that may not be fully understood.

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

Its already in the first reply.
 
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.
 
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Dear mfb, Thank you for taking the time to comment on my questions. It is illuminating and much appreciated.
 
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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?
 
See the second part of my previous post. There is no reasonable model that would allow that.
 

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