Borexino and SOX

Borexino and SOX

Picture of the Borexino detector Borexino Collaboration Picture of the Borexino detector during the filling with liquid scintillator.

Borexino ^1 is a 300 ton liquid scintillator detector ^2 placed in the underground Laboratori Nazionali del Gran Sasso in central Italy. The unprecedented radio-purity of the scintillator ^3 was at the base of a series of spectroscopic measurements of neutrino species from the pp-cycle (pp ^4 – listed among the top 10 Physics Breakthroughs ^5, pep ^6, 7Be ^7, and 8B ^8 neutrinos), a unique success of Borexino.

Geoneutrinos, antineutrinos emitted along the decays of long-lived radioactive elements inside the Earth, are unique probes in order to determine the radiogenic heat produced in the deep Earth. Borexino, together with KamLAND in Japan, are the only two experiments being currently able to measure geoneutrinos ^9.

At the end of 2016, a strong 144Ce/144Pr antineutrino generator will be placed below the Borexino detector. This, so called SOX project ^10 has the aim to search for a hypothetical sterile neutrino of ~1 eV2. The data acquisition will last about 1.5 years. The next goals and principal activities of the Borexino/SOX projects are:

  • a new complete solar neutrino analysis based on the, so called, Phase-2 data (after an extensive purification campaign of liquid scintillator), which will lead to an improved measurement of 7Be, pep and possibly also pp and 8B neutrinos.

  • an attempt to perform the first observation of neutrinos from the CNO cycle.

  • final geoneutrino analysis based on the complete data-set, naturally closed after the insertion of the SOX antineutrino source.

  • SOX-related sensitivity and Monte Carlo studies, data acquisition, detector calibration with radioactive sources and, naturally, final data analysis.

If you are interested in a thesis do not hesitate to contact Livia Ludhova.

Ref:

  1. Borexino web site: http://borex.lngs.infn.it/
  2. G. Alimonti et al. (Borexino collaboration): The Borexino detector at the Laboratori Nazionali del Gran Sasso, Nucl. Instrum.Methods Phys. Res. A.600 (2009), 568–593.
  3. G. Alimonti et al. (Borexino collaboration): The liquid handling systems for the Borexino solar neutrino detector, Nucl. Instrum. Methods Phys. Res. A. 609 (2009), 58–78.
  4. G. Bellini et al. (Borexino Collaboration): Neutrinos from the primary proton–proton fusion process in the Sun, Nature 512 (2014) 383.
  5. http://physicsworld.com/cws/article/news/2014/dec/12/comet-landing-named-physics-world-2014-breakthrough-of-the-year
  6. C. Galbiati et al. (Borexino Collaboration): First evidence of pep solar neutrinos by direct detection in Borexino. Jour. Phys., Conf. Series 375 (2012) 042030.
  7. G. Bellini et al. (Borexino collaboration): Precision measurement of the 0.862 MeV 7Be solar neutrino interaction rate in Borexino, Phys. Rev. Lett. 107 (2011) 14130; C. Arpesella et al. (Borexino collaboration): First real time detection of 7Be solar neutrinos by Borexino, Phys. Lett. B 658 (2008) 101-108; C. Arpesella et al. (Borexino collaboration): Direct measurement of the 7Be solar neutrino flux with 192 days of Borexino data, Phys. Rev. Lett. 101 (2008) 091302.
  8. G. Bellini et al. (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 (2010) 033006.
  9. M. Agostini et al. (Borexino Collaboration): Spectroscopy of geoneutrinos from 2056 days of Borexino data. Phys. Rev. D 92 (2015) 031101; G. Bellini et al. (Borexino collaboration): Measurement of geo-neutrinos from 1353 days of Borexino, Phys. Lett. B 722 (2013) 295-300; G. Bellini et al. (Borexino collaboration): Observation of Geo–Neutrinos. Phys. Lett. B 687 (2010) 299-304.
  10. G. Bellini et al. (Borexino collaboration): SOX: Short distance neutrino Oscillations with BoreXino, JHEP 1308 (2013) 038.