Silicon PhotoMultipliers Laboratories

1. During an analysis of data from the Belle experiment we have found a new exotic charmonium-like state we called X*(3860) that decays into a D-anti-D-meson pair in exotic quarkonium-like states Zb(10610) and Zb(10650). For the first time it has been demonstrated that the Zb(10610) and Zb(10650) states are virtual.
2. Using data of the CMS experiment, obtained in proton-proton collisions with an energy of 8 TeV in a system of the mass center, studied the excited states of В mesons and found a B*s2(5840)0 → B0 K0S decay.
3. While studying heavy hadrons born in the CMS experiment performed on the LHC in proton-proton collisions with an energy of 13 TeV in the mass center system, we have discovered a whole series of decays, namely, a decay of the Λ0b-baryon Λ0b → J/psi Λ phi, a decay of the B0s meson with the formation of the exotic state X(3872) B0s → X(3872) phi, the B0 → psi(2S) K0S π+π− and B0s → psi(2S) K0S decays as well as detected a new beautiful strange baryon that decays in the Xi_b− π+π− channel.
4. We have developed next-generation photodetectors — a new type of silicon photomultipliers based on non-planar technology.
5. Our researchers have analyzed data accumulated using highly-granular scintillation hadron calorimeter based on silicon photomultipliers (SiPM) produced by National Research Nuclear University MEPhI, with an absorber made of steel and wolfram. We were the first to compare the characteristics of hadron showers in multi-layer calorimeters with identical elements but different absorbers and demonstrated the relation between the characteristics of showers and properties of materials.

Implementation of research results:

• We have developed silicon photomultipliers (SiPMs) with record-high parameters in terms of the efficiency of light detection.
• We have developed and manufactured prototypes of SiPM relying on the CMOS technology.
• The Laboratory has manufactured scintillation cells of a prototype of a hadron calorimeter for the detector of a future linear collider.
• We have modernized the central and terminal parts of the hadron calorimeter of the CMS experiment, replacing the photodetectors with silicon photomultipliers.
• The Laboratory has developed and fine-tuned software for calibrating the hadron calorimeter of CMS in the context of the high level of overlapping of events. The developed modules have been included in the software of the CMS experiment.
• We have developed a project of a Bonner spectrometer with SiPMs for controlling the level of the radiation background in the experiment room of CMS.
• We have developed a cosmic veto system made of scintillator strips with light detection by SiPMs for the СОМЕТ experiment (J-PARC, Japan) aimed at the study of muon-electron conversion.
• Six objects of intellectual property have been registered. 

• 8 internships abroad for undergraduate and postgraduate students.
• 9 researchers have completed professional development and additional training programs in the course «Silicon photomultipliers».
• 5 Candidate of Sciences dissertations, 2 Doctor of Sciences dissertations, 4 specialist's degree thesis, 3 postgraduate degree theses, 3 master's degree thesis., 14 bachelor's degree thesis have been prepared and defended.
• Three lecture courses have been developed and launched for master's degree students of National Research Nuclear University MEPhI: «Modern Astroparticle Physics» (David Besson), «Astroparticle Physics in Antarctica» (David Besson), «Applications of detectors with silicon photomultipliers» (Yelena V. Popova).
• We have developed the laboratory case study «Measuring the key parameters of silicon photomultipliers» and implemented it into the «Applications of detectors with silicon photomultipliers» course.

• Ten grants have been received.
• Four contract agreements have been fulfilled. 

• Research and Production Association «PULSAR» (Russia): joint research, developing  a technology for producing silicon photomultipliers using a special technology and the CMOS technology.
• Research and Production Complex «Technology center» (Russia): producing silicon photomultipliers with record parameters in terms of efficiency and temporal characteristics.
• DESY (Germany): joint research, student exchanges, creating and testing next-generation  calorimeters with high segmentation  for planned experiments.
• CERN (Switzerland): joint research, student exchanges, modernizing the hadron calorimeter in the CMS experiment. The employee of the Laboratory Pavel Parygin is  the coordinator of the group responsible for the operations of the hadron calorimeter of the detector of CMS. The employee of the Laboratory Sergey Polikarpov was coordinating the B-physical research group of the CMS collaboration for two years (2019–2021).
• KEK (Japan): joint research, analysis of experimental data            and developing detector systems of the experiments Belle and COMET.