INR RAS - international collaborations

• Particle physics - accelerators experiments
• Particle physics - nonaccelerator experiments
• Fundamental nuclear physics
• Research and design for charge particle accelerators
• Neutrino astrophysics, cosmic rays physics
• CERN

Particle physics - accelerators experiments

T2K is a neutrino experiment designed to investigate how neutrinos change from one flavour to another as they travel (neutrino oscillations). An intense beam of muon neutrinos is generated at the J-PARC (Japan Proton Accelerator Research Complex)nuclear physics site on the East coast of Japan and directed across the country to the Super-Kamiokande neutrino detector in the mountains of western Japan.

The beam is measured once before it leaves the J-PARC site, using the near detector ND280, and again at Super-K: the change in the measured intensity and composition of the beam is used to provide information on the properties of neutrinos.
Science Goals of T2K

•the discovery of ν_μ → ν_e ( i.e. the confirmation that θ₁₃ > 0 )

•precision measurements of oscillation parameters in ν_μ disappearance

•a search for sterile components in ν_μ disappearance by observation of neutral-current events

•world-leading contributions to neutrino-nucleus cross-section measurements

Experiment K2K (National Laboratory for High Energy Physics, (KEK, - Super-Kamiokande, Japan).
The evidence of the neutrino oscillations was discovered by the study of atmospheric neutrinos in 1998. In 1999, an accelerator based experiment was started to study this phenomena. This experiment is called the KEK to Kamioka long baseline neutrino oscillation experiment (K2K). The neutrinos are artificially generated by using the proton accelerator at KEK and observed in the Super-Kamiokande detector located 250km away from KEK.

This experiment was completed in Nov. 2004. As a result, 112 neutrino events are observed in Super-Kamiokande, while the expected number of events without oscillations is 158. The probability to observe the deficit without neutrino oscillations is estimated to be 0.0015% and this deficit confirms the prediction of the neutrino oscillation discovered by the observation of atmospheric neutrinos.

The main goal of the experiment E246 at KEK (National Laboratory for High Energy Physics, Japan) is a search of T-violation in the decay К⁺—>m⁺p⁰ν. The experiment is sensitive to new physics beyond the Standard Model, in particular for testing the CP-violation mechanism through a Higgs exchange.

The main goal of the E949 experiment at BNL (Brookhaven National Laboratory, USA) is to measure a rare, flavor changing neutral current decay К⁺—>p⁺νν with a sensitivity of about 10^-11, an order of magnitude below the Standard Model prediction. This will result in a determination of the CKM matrix element |V_td| to better than 25%.

MINERvA (E938) is a neutrino experiment at Fermilab (USA) in the NuMI neutrino beam with primary goal of measuring the cross sections of quasi-elastic, resonance production and deep-inelastic neutrino scattering off different nuclear target.
MINERvA seeks to measure of few GeV neutrino and anti-neutrino interactions both in support of neutrino oscillation experiments and also to study nuclear effects in these interactions.
INR group is actively working in the data taking, quasi-elestic events reconsruction, analysis, and studing of the exclusive charged-current quasi-elestic cross section. The group also is working on the analysis of the ratios of neutrino inelastic cross sections for different nuclear targets.

The NOvA (E929) long-baseline neutrino experiment uses an upgrated NuMI neutrino beam at Fermilab and 14-kton detector to precision measurement muon-to-electron oscillation and muon neutrino disappearence probability. This experiment will provide measurement of mixing angle θ₁₃ and the neutrino mass hierarchy, and the charge-parity (CP) violating phase δ.
The NovA will also determ with high precision many oscillation parameters (mixing angles and squared-mass differences). The observation of CP-violation in the lepton sector, while groundbreaking on its own, would provide an experimental underpinning for the basic idea of leptogenesis as an explanation for the baryon asymmetry of the universe.
INR group is actively working in detector construction, commissioninig and data taking. The group performs several type of analyses: neutrino events reconstruction, analysis, calculation of the off-axis NuMI neutrino beam, and quasi-elastic cross section of neutrino scattering off nuclei.

Gran Sasso - Oscillation Project with Emulsion-tRacking Apparatus - experiment OPERA