A new experiment kills hope for a new physics

by time news

In 2014, a team of researchers from the LHCb, one of the four large detectors at the Large Hadron Collider (LHC), the world’s largest particle accelerator, announced the discovery of a “slight discrepancy” in the production of muons and electrons. Proton collisions, in effect, produced a type of very massive particle called B mesons which, when decomposed, in addition to the pairs of particles and their expected antiparticles (an electron and a positron or a muon and an antimuon) also produced a unexpected type of meson, the kaon. According to the Standard Model, the grand theory that describes how all subatomic particles behave, these two types of ‘couples’ should occur with the same frequency after collisions, but the LHCb data suggested they did not. The electron-positron pairs. indeed, they seemed to occur more frequently. During the following years, different groups of physicists repeated the experiment and the so-called ‘B meson anomaly’ seemed to gain more and more strength. It even reached a level of confidence known as 3 sigma, close to the 5 sigma level required before any discovery can be officially announced. Different measurements related to B mesons, moreover, further reinforced the idea that a ‘discrepancy’ with the Standard Model had finally been found, an unforeseen ‘thread’ that could be pulled to discover a totally new physics capable of reaching as far as current theory does not go. The Standard Model, in fact, despite its countless successes, has not been able to explain dark matter or energy, nor the absence of antimatter in the Universe, nor to clarify whether it also explains gravity, like the other forces of Nature. , is ‘quantizable’, that is, whether or not a particle carrying the minimum unit of gravity exists, in the same way that they exist for electromagnetism or the weak nuclear force. A bucket of cold water But the latest results of the LHCb experiment at CERN, announced just a few days ago, have been a real bucket of cold water for physicists, who have seen their hopes of being very close to an important discovery suddenly vanish. . The harsh reality, after all, is that electrons and muons are produced at the same rate, exactly as the Standard Model predicts and without any discrepancy. The disappointing announcement was made on December 20 by LHCb physicist Renato Quagliani during a seminar at CERN itself. Around the same time, the LHCb team posted two studies on the arXiv prepublication server (here and here) detailing their new analysis. In the words of Florencia Canelli, an experimental physicist at the University of Zurich and working on another LHC experiment, “My first impression is that this analysis is much more robust than the previous ones. And it has revealed how a series of astonishing subtleties had conspired to produce an apparent anomaly.” The latest results, in effect, include more data than previous LHCb measurements on B-meson decays, and also a more thorough analysis of possible confounding factors. The apparent discrepancies in previous measurements involving kaons were due in part, explains LHCb spokesman Chris Parkes, a physicist at the University of Manchester in the UK, to the misidentification as electrons of some other particles that actually They were not. And it is that, clarifies the physicist, although the LHC experiments are good at capturing muons, “electrons are more difficult to detect.” No signs of a new physics As reported in the latest issue of the journal ‘Nature’, these results will undoubtedly disappoint a good number of theoretical physicists, who have spent years trying to find models capable of explaining the alleged anomaly. “I’m sure,” Parkes says, “people would have liked us to find a flaw in the Standard Model, but in the end you do the best analysis possible with the data you have and see what nature gives you. That’s how science works.” Although rumors about these results had been circulating for months, their publication has surprised the scientific community, because the ‘mirage of the anomalies’ detected began to draw a coherent and hopeful image. In fact, many thought that they were close to detecting a new elementary particle, never seen before and not predicted by the Standard Model, capable of affecting the decays of B mesons. In general, the researchers praise the ‘honesty’ of the team of the LHCb in admitting that their previous results were wrong, although many lament the fact that they took so long to realize it. However, and despite the prevailing disappointment, all is not lost, since some other anomalies detected in other experiments could be real, and the hopes of finally finding a new physics now rest on a measurement from last April who found that the mass of a particle called the W boson is larger than expected. Some, however, believe that this discrepancy could be due to simple calculation errors. Only time will tell. The only sure thing is that, at least for now, the long-awaited new physics will have to wait. MORE INFORMATION noticia No A city inside an asteroid noticia Yes Hominids already sailed the seas almost 200,000 years before the appearance of Homo sapiens ———– As every year, the draw returns on December 22 extraordinary Christmas Lottery, which on this occasion distributes 2,500 million euros. Here you can check Christmas Lottery, if your ticket has been awarded any of the prizes and with how much money. Good luck!

You may also like

Leave a Comment