**Rozpad Bozonu Higgsa na dwa miony; w detektorach ATLAS i CMS w LHC o... (@Fake_R)

Rozpad Bozonu Higgsa na dwa miony; w detektorach ATLAS i CMS w LHC otrzymano sygnały (o wartości powyżej 3σ) wskazujące na zaobserwowanie po raz pierwszy tego rzadkiego procesu dotyczącego bozonu Higgsa i oznaczającego jego interakcję również z leptonami drugiej generacji - ogłosił zespół CERN na 40 Międzynarodowej Konferencji Fizyki Wysokich Energii w Genewie.

CMS achieved evidence of this decay with 3 sigma, which means that the chance of seeing the Higgs boson decaying into a muon pair from statistical fluctuation is less than one in 700. ATLAS’s two-sigma result means the chances are one in 40. The combination of both results would increase the significance well above 3 sigma and provides strong evidence for the Higgs boson decay to two muons.

“CMS is proud to have achieved this sensitivity to the decay of Higgs bosons to muons, and to show the first experimental evidence for this process. The Higgs boson seems to interact also with second-generation particles in agreement with the prediction of the Standard Model, a result that will be further refined with the data we expect to collect in the next run,” said Roberto Carlin, spokesperson for the CMS experiment.

Wcześniej obserwowano już rozpady bozonu Higgsa na bozony W, Z, "cięższe" leptony (taon) oraz najmasywniejsze kwarki - wysokiego i niskiego (2018 r.). Interakcja pola Higgsa z "lżejszymi" cząstkami (tj. miony) siłą rzeczy jest "słabsza", dlatego też przekroczenie progu 5σ dla rozpadu bozonu Higgsa na dwa miony będzie kolejnym doskonałym potwierdzeniem przewidywań Modelu Standardowego. Badacze spodziewają się uzyskać te rezultaty kiedy przejdzie modernizację do standardu HL-LHC (High-Luminosity LHC).

The Higgs boson is the quantum manifestation of the Higgs field, which gives mass to elementary particles it interacts with, via the Brout-Englert-Higgs mechanism. By measuring the rate at which the Higgs boson decays into different particles, physicists can infer the strength of their interaction with the Higgs field: the higher the rate of decay into a given particle, the stronger its interaction with the field. So far, the ATLAS and CMS experiments have observed the Higgs boson decays into different types of bosons such as W and Z, and heavier fermions such as tau leptons. The interaction with the heaviest quarks, the top and bottom, was measured in 2018. Muons are much lighter in comparison and their interaction with the Higgs field is weaker. Interactions between the Higgs boson and muons had, therefore, not previously been seen at the LHC.

The results, which are so far consistent with the Standard Model predictions, used the full data set collected from the second run of the LHC. With more data to be recorded from the particle accelerator’s next run and with the High-Luminosity LHC, the ATLAS and CMS collaborations expect to reach the sensitivity (5 sigma) needed to establish the discovery of the Higgs boson decay to two muons and constrain possible theories of physics beyond the Standard Model that would affect this decay mode of the Higgs boson.