ATLAS finds evidence of rare Higgs boson decay

ATLAS physicists searched the entire dataset of the Run 2 session of the Large Hadron Collider for

collisions with a photon, as well as with two leptons, the total mass of which was less than 30 GeV.In this region, decays with virtual photons should prevail over other processes that produce the same final state.ATLAS measured the signal velocity of the Higgs boson in this decay channel, which is 1.5 ± 0.5 times higherThe probability that the observed signal was caused by background fluctuations is less than 1 in 1000.

Considering that from the upcoming program at the LHC withWith a high luminosity, a large amount of data is expected, the study of rare Higgs boson decays will become the new norm. This will allow physicists to move from presenting evidence of their existence to confirming their observations and conducting detailed studies of the properties of the Higgs boson, which will lead to even more rigorous tests of the Standard Model.

Observation of the decay of the Higgs boson into a photon anda lepton pair will allow physicists to study charge parity symmetry or C-parity (CP). Combined parity, CP-symmetry is the product of two symmetries: C - charge conjugation, which turns a particle into its antiparticle, and P - parity, which creates a mirror image of the physical system. The strong interaction and electromagnetic interaction are invariant with respect to the combined CP transformation operation, but this symmetry is slightly broken in some types of weak decay. Historically, CP symmetry was proposed by Lev Landau to restore order after the discovery of parity violation in the 1950s. However, in 1964, James Cronin and Val Fitch showed that CP symmetry can also be broken.

When physicists who study kaon particles noticed , to their surprise, that this was the case in the world of particle physics Since then, the delegates have learned that CP violation is a sign of the electroweak interaction, and have incorporated it into the Standard Model.

But with the decay of the Higgs boson into three particles, twoof which are charged, physicists will be able to check if the decays are in a preferred direction, which will allow researchers to improve their understanding of the causes of CP violation and may even lead to clues for new physicists beyond the Standard Model.

Read more

Look at an 8 trillion pixel image of Mars

A nuclear rocket engine is being built for flights to Mars. How is it dangerous?

Abortion and science: what will happen to the children who will give birth

An electron volt is an off-system unit of energy used in atomic and nuclear physics, in elementary particle physics and in closely related and related fields of science.

The Standard Model is a theoretical construction inphysics of elementary particles, which describes the electromagnetic, weak and strong interactions of all elementary particles. The modern formulation was completed in the mid-70s after the experimental confirmation of the existence of quarks.

Fluctuation is any random deviation of any value.

Charge parity (WITH-parity) is one of the quantum numbers of a truly neutral particle (or other quantum-mechanical system), which determines the behavior of its state vector under charge conjugation.

Higgs boson - elementary particle, field quantumHiggs, which necessarily arises in the Standard Model of particle physics due to the Higgs mechanism of spontaneous breaking of electroweak symmetry.