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‘Centauro-I’ データ再解析
近畿大学・理工
玉田雅宣
2004年11月5日 RCNP
チャカルタヤ宇宙線観測所
（海抜 5200m; Bolivia)
Chacaltaya two-storey chamber
(5200m a.s.l., Bolivia)
starting point
shallow : e, g
deep : hadron
shape
cascade curve : e, g
multiple peaks : hadron
g/hadron identification
shower energy
e, g : Eg
hadron : kg Eh
some characteristics of the measurement
X-ray film
space resolution
50 ~ 100 mm
DE/E ~ 20%
(relative)
shower energy
spot darkness
(by cascade theory)
microphotometer
Eth = 1~2 TeV
nuclear emulsion
~20 mm
DE/E < 20%
(absolute)
track counting
microscope
Eth ~ 0.1 TeV
atmospheric family



Eg, Rg
Eh(g), Rh
emulsion
chamber
atmospheric family (A-jets)
measuement of zenith angle & azimuthal angle
by microscope
shower projection map
family
Chacaltaya chamber no.15
Exposure : October 1969 ~ July 1970
Chamber no.15
50 cm
N=7(≥1TeV) : 27 TeV
40 cm
N=138 (≥0.2TeV) : 203 TeV
CENTAURO : original data and interpretation
1~2 cm
Nh~100, < pt > ~1.8 GeV/c , non-p0 production
Centauro-I : previous interpretation
@ Interaction energy : E0 ~ 1,600 TeV
observed : Evis = 230 TeV
correction for passing through
Etot =320 TeV
<kg> = 0.2
@ Production height
E0 =1,600 TeV
H ~ 50m
geometrical convergence
d~6mm, Dd~200mm
@ Number of secondaries
@ Number of neutral pions
@ pt of secondaries
N ~ 100
Np0 ~ 0
<pt>~1.8GeV/c
@ Centauro fireball mass M~230GeV
Serach for Centauro in CERN SppS
Phys. Lett. B 180 (1986) 415
Phys. Lett. B 122 (1983) 415
Serach for Centauro in TEVATRON
FERMILAB-Conf-96/205-E
FERMILAB-Conf-94/343-E
re-analysis
Shower-cluster in S55 is not an upper body
of that in I12 !!
50 cm
Chamber no.15
40 cm
gap-passing atmospheric family ??
atmospheric jet produced at 50m above the chamber ?
V.V.Kopenkin et al.; PRD68(2003) 052007
CORSIKA/QGSJET
impossible !!
Atmospheric family of very small lateral spread ?
( narrow family )
Ng - <Rg> correlation
(100<SEg<1,000TeV)
atmospheric families
observed in Chacaltaya
chambers
(~1/156)
Simulations
CORSIKA/QGSJET
(~3/1,234)
x, o ; Simulations : CORSIKA/QGSJET
narrow family : ~6/6,216
narrow family が gap を通過する確率
★ narrow family [ n(E≥2TeV)≥20 & <R>≤3mm ] の頻度
{100 TeV ≤ SEobs < 1,000 TeV}
Chacaltaya two-storey chamber : f = 1/156 ~ 6 x 10-3
CORSIKA/QGSJET
: f = 6/6216 ~ 1 x 10-3
★ gap が占める割合
: p = Sgap/S ~ 0.05
C15 upper chamber の全面積
: S = 44.2 m2
gap の全面積
: Sgap= 2.44 m2
narrow family が gap を通過する確率
f x p = (0.5 ~ 3) x 10-4
C-jet with very large pt and multiplicity ?
carbon layer
(23 cm)
147 cm
d ij
d ij+Dd ij
no geometrical
convergence to target
layer !!
a bundle of C-jets ?
Comparison with
showers in 13 C-jets in
the event ‘Centauro-IV’
Comparison with simulations : QGSJET model
g-rays are decay products
of pi-zeros in target layer
carbon layer
(23 cm)
147 cm
ij
Ej
Ei
a bundle of C-jets !
again very exotic !!
a bundle of hadrons
w/o accompanying grays
no collisions
in the upper chamber !!
158 cm
≥ 28 collisions
In the target layer !!
★これまでの上下対応は間違い
発生高度 H=50m (<pt> ~ 2 GeV/c) は決まらない．
★上段チェンバーに、対応するファミリーは見つからない．
★上段チェンバーのブロック間の隙間を通過した拡がりの非常に
小さいγ線ファミリーか？
◎完全には否定できないがその可能性は小さい！．
★大多重度、大Pt の C-jet か？
◎カーボン層への有意な収斂は観測されない。
★複数個の C-jets の重ね合わせ（hadron bundle) ?
◎エネルギー分布、Mgg-分布：
~30 のC-jets の重ね合わせでよく説明できる．
◎上段チェンバーにシャワーが観測されないというの
は説明しにくい．
★新しい解釈が必要：strange quark matter ?
strange quark matter
L : explosion length of
small strangelet in Pb
l : collision mean free
path of nucleons in Pb
number of hadrons which interact in the upper chamber
number of hadrons which interact in the upper chamber
and target layer
number of hadrons which interact in the target layer:
I2 - I1
Expected number of collisions
in the upper chamber
Strange Quark Matter
non-strange
baryon
SQM fireball
strangelet
unstable meta-stable
neutron
bundle
evaporation
of neutron
CASTOR: CMS/LHC
A.Angelis et al.; J.Phys.G23(1997) 2069
E.Gladisz-Dziadus & Z.Wlodarczyk ; J.Phys.G23(1997) 2057
TOTEM experiment at LHC
nuclear interaction at E0 ~ 1017eV
V.Avati et al.; EPJdirect A1(2003)1

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