Gamma-ray bursts(GRBs for short) are short flashes of high-energy
photons that appear on average about once a day at an
unpredicatable time from unpredictable directions in the sky.
GRBs have been the most mysterious astronomical phenomenon in
the universe for about 30 years after the discovery.
The discovery of X-ray afterglows and optical and radio counterparts
to GRBs has enables redshift measurement of GRB sources and hosts,
thereby confirming the hypothesis that the origins of GRBs are
One leading model for a GRBs involves a newtron star merging with
another neutron star or with a black hole, but the production
mechanism of gamma-rays in GRBs are not yet known at all.
Currently GRBs are widely believed as dissipation of kinetic
energy of relativistic motion produced by an expanding fireball
with a Lorentz factor of $B!A(B 102-3.
The possibility of very strong emission of
TeV gamma-rays is considered to be synchrotron radiation of
protons accelerated up to $B!A(B 1020eV.
Our study is made for a search for TeV counterparts to GRBs observed
by BATSE using the Tibet II/HD air-shower dataset.
The BATSE on board the Compton GRO, a wide field instrument
sensitive to gamma-rays from 20 keV to 600 keV, has detected
2704 bursts from 1991 to 2000.
The analysed Tibet data are taken during the period October
1995 through September 1999.
BATSE detected 67 GRBs within the field of view of Tibet array
during this period. GRB971115a is found to be the most prominent
GRB having Power value of 6.05.
The probability that Power value is greater than 6.05 is occurred by
the statistical fluctuation is estimated by Monte Carlo simulation,
and was found to be 2 $B!_(B 10-1.
Therefore, such Power value can be underestood as consistent with
So, no clear significant TeV gamma-ray bursts were detcted from our
analysis of Tibet II dataset.