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Guido Pizzella Universita’ di Roma Tor Vergata INFN- Frascati

Guido Pizzella Universita’ di Roma Tor Vergata INFN- Frascati. Coincidences between the g.w. detectors EXPLORER and NAUTILUS. LISA. ROG Collaboration LNF, Roma1, Roma2. CERN RE 5. LNF INFN. LNGS. Calibration: a) gravity induced by a rotor b) cosmic ray showers.

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Guido Pizzella Universita’ di Roma Tor Vergata INFN- Frascati

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  1. Guido PizzellaUniversita’ di Roma Tor VergataINFN- Frascati Coincidences between the g.w. detectors EXPLORER and NAUTILUS

  2. LISA

  3. ROG Collaboration LNF, Roma1, Roma2 CERN RE 5 LNF INFN LNGS

  4. Calibration:a) gravity induced by a rotorb) cosmic ray showers (in addition to small applied forces)

  5. Astone et al., Z.Phys.C50:21-29,1991 Eur. Phys. J. C 5, 651-664 (1998) Vmeasured=19.1±0.7mV Vexpected=21.1±0.6mV

  6. Cosmic Rays Large signals Small signals

  7. energy threshold time

  8. Large signals Explorer 2003 Explorer

  9. Large signalsNautilus 2004

  10. Small signals

  11. Measurements with an electron beam at DANE

  12. aluminum Buonomo et al., Astropart.Phys.24:65-74,2005

  13. niobium

  14. Search for coincidences Cross-section depending on orientation = osin4()

  15. Sidereal hour 3.5

  16. Sidereal hour 12.2

  17. Polarized sources in the Galactic Centre Astron.Astrophys.421:811-813,2004 3.5±1.5 Efficiency of detection Sidereal hour 3.5 hour

  18. Sources uniform over the galactic disk Sidereal hour

  19. Measurements during the years1998, 2001, 2003, 2004

  20. energy threshold time

  21. 1998

  22. In the conclusions of the 1998 paper presented to the IGEC collaboration in 1999 and 2000 and written together with the LSU group: ...we find an excess of coincidences at zero time delay in the direction of the galactic centre. Class.Quant.Grav.18:243-252,2001

  23. 2001 Class.Quant.Grav.19:5449-5463,2002

  24. 2003 Class.Quant.Grav.23:S169-S178,2006

  25. 2004

  26. 3.5±1.5 sidereal hours all sidereal hours

  27. Combining the probabilities

  28. The coincidences excesses are concentrated at certain times

  29. 1998 2001 2003 2004 Day of year

  30. Searching if any special astrophysical phenomena occurred in the period 7-17 September 1998

  31. Last figure

  32. 7-17 September 1998 1.1 10-4

  33. ConclusionWe have shown a coincidence excess with very small probability to be accidental (1% in total, 0.02% at selected sidereal hours). Gravitational waves ?

  34. end

  35. 6432 ore 2004 nc=27 <n>=1.8 Offset=6.7 ms s=5.9 ms

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