The aim of the laboratory is the search for new physics in the international MEG and COMET experiments. They are aimed at finding processes that violate the law of lepton number conservation in the charged sector.

Such processes are forbidden in the Standard Model, but at the same time they appear in many new theories. Therefore, their study is important to search for new physics beyond the Standard Model, including energies on the order of 2 higher than those available in the Large Hadron Collider. These tasks are particularly important in light of the fact that so far indications of the presence of physics not consistent with the Standard Model are not observed in the experiments at the Large Hadron Collider.

The aim of the MEG experiment (PSI, Switzerland) is the search for the neutrinoless decay of a positive muon into a positron and a gamma ray with 5x10-14 sensitivity. The aim of the COMET experiment (JPARC, Japan) is the search for the neutrinoless conversion of a negative muon into an electron in the atomic nucleus field with 10-16 sensitivity. MEG and COMET experiments are sensitive to different manifestations of new physics, and therefore complement each other. New physics can be detected in one of them, or both, and a joint analysis of the data in these experiments helps to understand its nature.

Experimental detection of processes in violation of lepton number will be one of the most important achievements in the physics of fundamental interactions, along with such results as, e. g., discovery of neutrino oscillations awarded with the Nobel Prize. The negative result of experiments will test a lot of new models that is why it is important.

At the present moment the work on the development of hardware and software for MEG and COMET experiments is underway. Laboratory staff has made fundamental contribution to the creation of many of them.

The MEG experiment results are the following:

  •  The necessary intensity of the beam 108 Moyun / s has been obtained for the second phase of the experiment, while the size of the beam increases by less than 5%;
  •  The new method for the diagnosis of high-intensity beams at low energy has been developed and experimentally tested;
  •  The method for the reconstruction of events in the drift chamber in conditions of a large number of back-end operations has been developed;
  •  Electronics for the active target has been designed and its model has been tested in real-world conditions.
The COMET experiment results are the following:

  •  Analog electronics for electromagnetic calorimeter has been developed and tested on a test electron beam;
  •  The design of the electromagnetic calorimeter module has been offered. According to this design the recording part is located in vacuum and the electronics is placed outside. The proposed solution is accepted by the collaboration as the basis;
  •  In order to unify the data collection the ADC board developed for the tracking system has been modified for the needs of the electromagnetic calorimeter;
  •  The pretrigger of the electromagnetic calorimeter project has been developed and approved by the collaboration;
  •  The developed algorithm of events reconstruction in the tracking systems has improved the momentum resolution by 2 times;
  •  The prototype of the counting-tube for the system of active protection from cosmic radiation has been built and is being tested.
The laboratory is part of The NSU interdisciplinary center of elementary particle physics and astrophysics.

International partners of the laboratory: Paul Scherrer Institute (Switzerland), the National Institute of Nuclear Physics (Italy), University of Tokyo (Japan), the Centre for High Energy Physics (Japan), Osaka University (Japan), University of Kushi (Japan).

Head of Laboratory: PhD. in Physics and Mathematics, assistant professor Dmitri Grigoriev, grigoriev@inp.nsk.su

Division of elementary particle physics
Budker Institute of Nuclear Physics