Department №40

Neutrino astrophysics

Neutrino astrophysics opened more than thirty years ago when Homestake experiment had for the first time detected neutrinos from the Sun (Nobel Prize in physics for 2002). Since then the experimental facilities were continuously improving, allowing more profound study of the properties of solar insides and neutrinos themselves. Neutrino signal from the Supernova explosion in Large Magellanic Cloud, observed on February 23, 1987 by several detectors became an essential experimental triumph. That fact allowed for the first time performing the experimental test of existing stellar collapse models.

Nowadays experimental neutrino astrophysics deals with the challenging tasks of detection of neutrinos coming from the wide range of galactic and extragalactic sources. Department’s members are the active participants of the Borexino project starting from its very beginnings. Borexino is a multipurpose neutrino detector taking data in the Gran Sasso underground laboratory (Italy). Borexino solves the following tasks among the others: study of neutrinos from the Sun and other astrophysical sources (Supernovas, Gamma-Ray Bursts, clumps of Dark Matter etc); study of geo-neutrinos; search for rare processes beyond the Standard Model of particle physics.

The most significant results obtained by Borexino up to now are:

  • First in the world measurements of the solar “beryllium” and pep-neutrino fluxes;
  • Experimental confirmation of the absence of a day-night asymmetry of 862 keV Be-7 solar neutrino rate;
  • Measurement of the solar “boron” neutrinos flux with the lowest energy threshold ever achieved;
  • Borexino is one of the two detectors in the world, which registered the geo-neutrino signal.

Publications:

  1. Borexino Collaboration, Precision measurement of the 7Be solar neutrino rate in Borexino, Phys. Rev. Lett. 107, 141302 (2011)
  2. Borexino Collaboration, Absence of a day-night asymmetry of 862 keV Be-7 solar neutrino rate in Borexino, Phys. Lett. B, 707 (2012)
  3. Borexino Collaboration, First evidence of pep solar neutrinos by direct detection on Borexino, Phys. Rev. Lett. 108, 051302 (2012)
  4. Borexino Collaboration, Measurement of the solar 8B neutrino rate with a liquid scintillator target and 3 MeV energy threshold in the Borexino detector, Phys. Rev. D 82, 033006 (2010).
  5. Borexino Collaboration, Study of solar and other unknown anti-neutrino fluxes with Borexino at LNGS, Phys. Lett. B 696, 191 (2011)

Contact Person:

Litvinovich Evgeny

e.litvinovich@mail.ru