Physicists, who work on the LHC, recently came across a new phenomenon, which was never predicted by any of existing theories. In a few words, protons collide and generate hundreds of particles. And among these particles, scientists detected pairs, movements of which were coupled for some unknown reason.

This unexpected phenomenon was detected for the first time here, in Large Hadron Collider, and now it is time for theoretical physicists to explain it. Experimentalists, keeping fingers crossed, hope that they have reached the point, from which new, unexplored physics starts. Head of the group of Russian physicists, working on the CMS (Compact Muon Solenoid) detector, new effects and phenomena will now be detected oftener.

The CMS, which is one of two large general-purpose particle physics detectors on the LHC, is the facility, on which these strange two-body corellations were spotted. The Large Hadron Collider, built on the border between France and Switzerland by CERN (the European Organization for Nuclear Research), was officially launched in September 2008, and scientists from over 70 countries have participated in this ambitious scientific programme.

 

 

The particle accelerator now works at energy of 3.5 TeV (tera-electron volt), which three times exceeds energies, reached on any other existing accelerator. The paper, written by CMS participants and describing results of a search for all particle pairs, which form during collisions, as well as measurements of motion direction diversity. Scientists noticed that some pairs of particles, which moved away from each other at light speed, kept moving along the same angle, as if they have been somehow coupled together. This phenomenon wasn’t predicted by model calculation, scientists say.

According to researchers, physicists have already offered several qualitative explanations for this effect; however, no quantitative descriptions have yet been made. Quantum chromodynamics, the cutting edge of physical theory, which describes interactions between quarks and gluons, states that these most fundamental particles cannot be born one by one, only in pairs or groups.

When researchers “knock out” one quark or gluon, the particle “wants” to leave, but it cannot, because it has to carry a “string” with virtual particles (a virtual particle is a particle that exists for a limited time and space, introducing uncertainty in their energy and momentum due to the uncertainty principle). This “string” stretches between an object, which left, and remains of a proton, responsible for the reaction. The result is correlation, which may appear in the plane of the reaction, physicists say.

 

 

Large Hadron Collider, the largest particle accelerator in the history of mankind, was relaunched in November 2009. Its 27-kilometer-long round tunnel is the place, where protons beams collide at speeds, reaching speed of light. Studying these collisions, scientists hope to get new information about structure of matter. The more collisions will be detected, the higher a probability of some unique phenomenon happens is.

The Compact Muon Solenoid was designed in order to detect as many new particles and effects as possible after proton-proton and nucleus-nucleus collisions under high energies. This facility allows measuring properties of already known particles with extreme accuracy, as well as searching for previously undetected and unpredicted effects and phenomena.

Source: Science News

Kizilova Anna