Tevatron’s false alarm

As the BBC reports, independent checks on a separate experiment at Fermilab’s Tevatron accelerator have found no evidence of “a completely new, unanticipated particle” the BBC had previously reported researchers had said they had found “compelling hints of”.  And, therefore, no signal of “a new fundamental force of nature, and the most radical change in physics for decades.”

Which means Jon Butterworth was right to be sceptical [and his money’s safe! – Ed] Indeed.  I did say that BBC report was somewhat excited at the time.

As the Guardian’s Ian Sample notes

“We don’t see anything in this area that is consistent with what CDF has observed and we actually exclude the signal observed by CDF with a very, very high probability,” said Stefan Söldner-Rembold, from the University of Manchester, who is a spokesman for the DZero experiment. “In terms of this effect being a real new physics discovery, I think it is close to dead.”

The analysis focused on collisions that produced a particle called the W boson and two “jets” of quarks. While the CDF team saw a bump corresponding to a particle with a mass of around 145 GeV (gigaelectronvolts), the DZero team saw no such signal.

The W boson carries the weak force, which plays a crucial role in nuclear reactions in the sun and governs certain kinds of radioactive decay. Quarks are fundamental particles of matter found in protons and neutrons.

The conclusion from the DZero group will come as a blow to the CDF team, who must now go back to their analysis to try and understand what caused the phantom signal. The experiments have produced hundreds of results over the last decade, and they usually give consistent answers. Given the enormous complexity of the data analysis, it is to be expected that such a discrepancy will sometimes occur.

But, of course, there may still be further wrinkles ahead…