The new CMS and ATLAS results were obtained by combining several separate analyses of Higgs boson production modes and their corresponding decay modes. Studying the combinations of particles that can create a Higgs boson-called production channels or modes-and the particles into which it decays-called decay modes-gives physicists a better understanding of the particle. The collisions trigger the formation of new particles that interact-sometimes turning into Higgs bosons. Two beams travel in opposite directions and collide at four points along the ring, including at the CMS and ATLAS detectors. Higgs bosons are created by accelerating beams of protons around the LHC’s 17-mile-circumference circular tunnel at close to the speed of light. “We’ve only gotten better and better at seeing it.” Precision measurements In the last decade, “the Higgs boson has only gotten 'bigger,'” says Fermilab CMS researcher Nicholas Smith, speaking metaphorically (the Higgs boson mass remains approximately 125 GeV, now measured to a precision of 0.1%). During this time, the collision energy was raised from 8 teraelectronvolts to 13 TeV, increasing the rate of Higgs production and resulting in much more data for the experiments to collect and analyze.įor example, ATLAS estimates that about 9 million Higgs bosons were produced in the ATLAS detector during Run 2-30 times more than in 2012 (though they only analyze a fraction of that number). In the last 10 years, the LHC completed its second run of data-taking, called Run 2. (She started working at CERN on July 3, 2012.) “It’s really fun to have this new particle that we can analyze in detail and see what it is, how it behaves,” says Brost, who now works for Brookhaven.ĭaniel Guerrero, a CMS researcher at DOE’s Fermi National Accelerator Laboratory, agrees: “After we discovered the Higgs boson, it’s like a complete new field of exploration opened for experiments at the LHC.” Liza Brost is an ATLAS physicist who has been studying the Higgs boson since its discovery-literally. And it appears to be that it’s happening just the way it’s predicted.” “Now we know a whole lot about the Higgs, because particle physics predicted how the Higgs would be produced, how it would decay, the signatures that we would see. “We would have never guessed it … It’s truly phenomenal. “What’s really surprising is how well the experiments have measured these properties,” says Sally Dawson, a theorist at Brookhaven and author of the book The Higgs Hunter’s Guide. “Nevertheless, there is room for new physics.” But, “it’s pretty neat to think about the idea.“The particle that was discovered looks more and more like the Standard Model Higgs boson,” says Kétévi Assamagan, an ATLAS physicist at the US Department of Energy’s Brookhaven National Laboratory who was convener for the experiment’s Higgs group from 2008-2010. How easily the diamonds could be recovered is unclear, he says. How practical it is, I don’t know,” says physicist Marius Millot of Lawrence Livermore National Laboratory in California, who was not involved with the new study. You take water bottle plastic you zap it with a laser to make diamond. The new technique could create nanodiamonds that are more easily tailored for particular uses, such as quantum devices made using diamond with defects where, for example, nitrogen atoms replace some of the carbon atoms ( SN: 7/6/18). Nanodiamonds are commonly produced using explosives, Kraus says, a process not easy to control. “The oxygen sucks out the hydrogen,” he says, leaving behind carbon which can then form diamond. The oxygen seems to assist the diamond formation, says Kraus, of the University of Rostock in Germany. That makes it a better match to the composition of ice giant planets like Neptune and Uranus. But PET, which is commonly used in food and drink packaging, contains not just hydrogen and carbon but also oxygen. Previous studies had created diamonds by compressing compounds of hydrogen and carbon. Probing the material with bursts of X-rays revealed that nanodiamonds had formed. Each laser blast sent a shock wave careening through the plastic, amping up the pressure and temperature within. In the new study, researchers trained lasers on samples of plastic.
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