Strong Evidence for Higgs-Like Particle Announced this Morning
Collision event recorded with the CMS detector in 2012 at the Large Hadron Collider. The event shows characteristics expected from the decay of the Standard Model Higgs boson to a pair of photons (dashed yellow lines and green towers).
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(Inside Science) -- Results from two experiments at the Large Hadron Collider in Europe confirmed the existence of a new heavy particle, likely to be the long-sought Higgs boson, thanks to troves of particle-collision data that yielded discovery-level certainty upon analysis. The results, announced at a major particle physics conference in Melbourne, Australia, mark the culmination of a search for a heavy particle believed to give mass to elementary particles such as electrons and quarks. The announcements represent the current high-water mark for the $7-billion LHC particle accelerator at the Franco-Swiss border, which recreates conditions thought to exist fractions of a second after the Big Bang.
The two experiments, CMS and ATLAS, analyzed particle decay data from hundreds of trillions of particle collisions. At the ICHEP2012 conference earlier this morning, both reported "bumps" in the data around the 125 -126 GeV range of mass, suggesting the existence of a particle over a hundred times heavier than the proton, the core of the basic hydrogen atom, which is just about 1 GeV. Each experiment confirmed these results to about 5 sigmas of certainty, indicating that there is less than a one in three million probability that these were chance results resulting from something other than the presence of a new particle. These results follow earlier LHC results and the Monday announcement from the Fermi National Accelerator Laboratory in Illinois of evidence, extracted from the less powerful and now-retired Tevatron accelerator, for the particle at a level of three sigma.
Today's seminar had a sustained buildup, beginning with early media intimation. "Definitely a rock-concert vibe in the air, as folks have been camping out for a while to get into the auditorium. Doors still not open as yet," Sean Carroll blogged at Cosmic Variance. Web traffic was remarkably high, and as tweeters later bemoaned a choppy webcast from the organization where the World Wide Web was first developed, another website called havewefoundthehiggsbosonyet.org [Editor's note: Link is no longer active] changed its homepage to an emphatic three-letter word: Yes! The results came in the last runs of the experiments which ended about two weeks ago. The announcements were met by standing ovations and a surprisingly low number of questions at the end.
Stay tuned for a full Inside Science News Service feature, featuring scientists' reactions, later today!
Virat Markandeya is a contributing writer to Inside Science News Service.