Piero Galeotti

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Piero Galeotti Università di Torino and
INFN GianVittorio Pallottino Università di Roma
and INFN Guido PizzellaUniversità di Roma Tor
VergataINFN- Frascati
SN1987A revisited
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Results from LSD and KAMIOKANDE
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2h56m
7h35m
LSD
Kamioka
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0
Hours of 23 February 1987
Mont Blanc 45 pulses/hour gt 5 MeV Kamiokande
85 pulses/hour gt 7.5 MeV
(7.5 MeV corresponds to Nhit20)
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Mont Blanc neutrino telescope 1987
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Kamiokande neutrino telescope 1987
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Hirata et al. PR D 448 (1988)
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May the Supernova Bang more than once ?
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Kamiokande neutrino telescope 1987
New analysis

• The data have been supplied to us by the
  Kamiokande collaboration in 1987. We have
  acknowledged the collaboration in several papers

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relative Kamiokande time
IMB
no IMB
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11 ? in 12 s Nhgt20
7 ? in 6 s Nh gt 21
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relative Kamiokande time
IMB Egt15 MeV
no IMB Elt15 MeV
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Correlation of the Kamiokande and LSD neutrino
detectors with the Rome and Maryland
gravitational wave detectors
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We have searched for possible correlations
between the signals of the neutrino detectors and
those of the g.w. detectors
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The algorithm
C(f) 1/Nn Si ER(tif ) EM(tif )
Nn number of pulses (in the neutrino detector)
in a given period (say,
one hour) ti time of a pulse f common time
shift for a possible delay
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The background
Cb(f1, f2) 1/Nn S?? ER(f1) EM(f2)
Nn number of pulses (in the neutrino detector)
in a given period (say,
one hour) f1, f2 random time shifts for the
background
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We perform N random extractions of f1, f2 for the
background and count the number n of times when
Cb(f1, f2) gt C(f)
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N one million random data for the background
C(???1.?)72.6 K
Cb(f1, f2) with random f1, f2
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Mont Blanc 145 - 345 ( 5-neutrinos at 256
U.T.)
n
C(-1.1)
F 1.2 (second)
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What about Kamiokande ?

• (absolute time uncertainty 1 min)

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?c is the time correction in s
best ?c7.8 s
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Kamiokande has a time error 1 minute
Kamiokande time correction 7.8 s
Schramm and Truran (1990)
IMB
K
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New analysis of the original data
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Periods of one hour moved in steps of 6 min
n (N105)
hours of 23 February
n (N104)
with time correction of 7.8 s
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CONCLUSIONSThis new analysis reinforces the
idea of a long duration activity of SN1987A in
the neutrino emission.
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noi non doviamo desiderare che la natura si
accomodi a quello che parrebbe meglio disposto et
ordinato a noi, ma conviene che noiaccomodiamo
lintelleto nostro a quello che ella ha fatto,
sicuri tale essere lottimo et non
altro.Galileo in 1612 to Federico Cesi.

• THE END