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ABSTRACT: We formulate empirically the rapidity density distribution of produced particles in multiple particle production. The assumed mechanism is that the produced particles are emitted isotropically from several emitting centers, located on the rapidity axis. The formula includes five adjustable parameters, which are to be determined by the experimental data of (pseudo-)rapidity density distributions and transverse momentum distributions at various energies. It is a distinguished difference of the present rapidity density distribution from those of other models that the particle production is suppressed strongly in the forward region. We discuss multiplicity and inelasticity at high energies, the pseudo-rapidity density distribution at LHC energy and some speculations, based on the present formulation. Comment: Talk presented at XVI International Symposium on Very High Energy Cosmic Ray Interactions ISVHECRI 2010, Batavia, IL, USA (28 June 2 July 2010). 8 pages, 13 figures
09/2010;
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ABSTRACT: Presenter: M.Tamada (tamada@ele.kindai.ac.jp), jap-tamada-M-abs1-he21-oral The features of the exotic cosmic-ray event "Centauro-I" are: (1) ¥ ¦ ¦ hadrons, unaccompanied by -rays, incident upon the chamber, (2) a reasonable lateral spread of these hadrons, and (3) no nuclear interactions of these hadrons in the upper chamber but ¦ interactions in the target layer. We propose a model of strange quark matter among the primary cosmic rays to describe the event.
01/2005; 00:101-104.
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H Aoki,
K Hashimoto,
K Honda,
N Inoue,
N Kawasumi,
N Martinic,
C Navia O,
N Ochi,
N Ohmori,
A Ohsawa,
L C Oliveira,
K Shinozaki, M Tamada,
R Ticona,
I Tsushima
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ABSTRACT: A hybrid experiment to operate simultaneously an air shower array, a hadron calorimeter and an emulsion chamber is under way at Mt Chacaltaya (5200 m, Bolivia). An event with a halo, a blackened area of ~1 cm on x-ray film of the emulsion chamber, was observed with the experiment. Information about the halo (Ehalo = 850 TeV) and on high energy particles of electromagnetic and hadronic components outside the halo (∑Eγ = 632.5 TeV and ∑E(γ)h = 278.8 TeV with a detection threshold of 2 TeV) was obtained from emulsion chamber data. Details about low energy hadrons were determined from the hadron calorimeter data, and characteristics of the accompanying air shower (Ne = 7.0 × 107, s = 0.59) were determined by the air shower array. We reconstruct the event, based on the observed data. The event is compared with simulated events, which supports the conclusion that nuclear interactions change their characteristics in the high energy region so as to result in stronger energy subdivision.
Journal of Physics G Nuclear and Particle Physics 01/2004; 30(2):137. · 4.18 Impact Factor
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ABSTRACT: A new analysis of mountain-top x-ray emulsion chamber data is presented.
We utilize a refined experimental apparatus and a standardized analysis
approach, including the simulated data. The results indicate that most
of the phenomena reported previously can be explained as fluctuations
within standard hadronic interaction physics. In the wide energy region
we see no indication of a large change in the primary composition.
Physical review D: Particles and fields 03/2002; 65(7):72004.
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C. Aguirre,
H. Aoki,
K. Hashimoto,
K. Honda,
N. Inoue,
N. Kawasumi,
Y. Maeda,
N. Martinic,
T. Matano,
N. Ohmori,
A. Ohsawa,
K. Shinozaki, M. Tamada,
R. Ticona,
I. Tsushima
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ABSTRACT: An experimental setup of an air shower array, hadron calorimeter, and emulsion chamber is being carried out at Mt. Chacaltaya (5200 m, Bolivia), in order to study the hadron interaction and the primary cosmic rays in the energy region exceeding 1015 eV. The number of hadrons in the air shower, detected by the hadron calorimeter, is discussed mainly in this paper. A comparison with the simulation shows that the number of hadrons in the air shower is not compatible with that of the simulation, indicating that the Feynman scaling law is violated more strongly than the one assumed in the simulation at 1016 eV. The average mass number of the primary cosmic rays, estimated from the distribution of the number of hadrons, is 〈lnA〉=2.8±0.5 at 1016 eV.
Phys. Rev. D. 07/2000; 62(3).
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ABSTRACT: The inelasticity distribution of hadron-lead collisions in the energy region exceeding 1014 eV is estimated on the basis of 66 events, induced by cosmic ray hadrons and detected at high mountain altitudes at Pamir (4300 m, 595 g/cm2). The distribution of the best fitting is approximated as g(K)dK=[α(1-K)m1-1+βKm2-1]dK, where m1=0.5, m2=1.125, α=0.26, β=0.55, giving 〈K〉=0.60. The errors of the parameters are discussed in the text. The distribution is compared with those which are based on theoretical models.
Phys. Rev. D. 12/1999; 61(1).
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C. Aguirre,
K. Hashimoto,
K. Honda,
N. Inoue,
N. Kawasumi,
N. Martinic,
T. Matano,
N. Ohmori,
A. Ohsawa,
F. Osco, M. Tamada,
R. Ticona,
I. Tsushima
Nuclear Physics B - Proceedings Supplements 01/1997; 52:209-211. · 0.88 Impact Factor
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N. Kawasumi,
I. Tsushima,
K. Honda,
K. Hashimoto,
T. Matano,
N. Inoue,
K. Mori,
K. Yokoi,
A. Ohsawa, M. Tamada,
N. Ohmori,
N. Martinic,
R. Ticona,
N. Gironda,
F. Osco,
C. Aguirre
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ABSTRACT: The observation of families and air showers is carried out at Mt. Chacaltaya (5200m, 540 g/cm2 atmospheric depth, Bolivia) by operating the emulsion chamber and the air shower array simultaneously. We summarize in this
paper the results of the experiment, leaving the description of experimental apparatus, experimental procedure, etc. elsewhere
(Kawasumi N.
et al., AIP Conf. Proc.,276 (1992) 88;Proc. XXIV ICRC, Rome,1 (1995) 201). The analysis relies on the data of 47 families of ΣE
γ≥10 TeV with the accompaniment of air showers.
Nuovo Cimento- Societa Italiana di Fisica Sezione C 10/1996; 19(6):1023-1029. · 0.35 Impact Factor
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N. Kawasumi,
I. Tsushima,
K. Honda,
K. Hashimoto,
T. Matano,
N. Inoue,
K. Mori,
A. Ohsawa, M. Tamada,
N. Ohmori,
N. Martinic,
R. Ticona,
N. Gironda,
F. Osco,
C. Aguirre
[show abstract]
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ABSTRACT: Simultaneous observations of families and accompanied air showers with emulsion chambers and the air shower array of electronic equipment at Mt. Chacaltaya (5200 m, 540 g/cm2) reveal that families bear the data of nuclear interactions generated deep in the atmosphere. 47 outstanding families with ΣEγ≥10 TeV are correlated with the accompanied air showers of the size 105–108. A scatter plot of the average family energy versus the size of the relative air shower requires further energy fractionizing process(es) in the propagation of high energy cosmic rays in the atmosphere, such as a larger dissipative mechanism in nuclear interaction, heavier chemical composition of the primary cosmic rays, etc. We reach the conclusion that nuclear interaction changes its features in the energy region E0≳1016 eV, because the heavier composition, proposed so far, is not sufficient for the required dissipative process. A comparison with the data from the HADRON experiment at a similar altitude with a similar technique shows that no larger deviations are present between both experiments. © 1996 The American Physical Society.
Phys. Rev. D. 03/1996; 53(7).
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T. Arisawa,
Y. Fujimoto,
S. Hasegawa,
K. Honda,
H. Ito,
V. V. Kopenkin,
H. Semba, M. Tamada,
K. Yokoi,
G. F. Fedorova,
I. P. Ivanenko,
A. K. Managadze,
I. A. Mikhailova,
E. G. Popova,
I. V. Rakobolskaya,
T. M. Roganova,
L. G. Sveshnikova,
O. P. Strogova
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ABSTRACT: Experimental results are presented on high energy cosmic-ray hadron
interactions recorded in homogeneous-type thick lead chambers (total
thickness being 60 cm and 110 cm) exposed at the Pamirs (atmospheric
depth 595 g/ cm2). High energy cosmic-ray hadron flux is
measured. The attenuation mean free path of the arriving cosmic-ray
hadrons of Ehγ >= 6 TeV measured in the
chamber is obtained as 252 +/- 30 g/cm2 of lead. However, for
the high energy hadrons (E(γ) >= 10 TeV) constituting
cosmic-ray families of the highest energy range, ΣE(γ) >=
700 TeV, which have been accumulated so far in the series exposures at
the Pamirs and analysed by MSU group, the attenuation mean free path of
hadrons in lead has turned out to be as short as
170-26+47 g/cm2 with 95% CL by the
maximum likelihood method. The present experimental result of such a
short attenuation length of hadrons in cosmic-ray families is
essentially consistent with that obtained for high energy hadrons
(E(γ) >= 10 TeV) constituting the ``Chiron-type'' families of
ΣE(γ)>100 TeV in the Chacaltaya two-storeyed chamber
experiments. The anomalous transition characteristics of high energy
hadrons in lead is found and examples are presented. The physical
significance of the experimental results on extremely high energy hadron
interactions is discussed.
Nuclear Physics B 07/1994; 424:241-287. · 4.66 Impact Factor
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ABSTRACT: The energy distribution of produced particles in multiple particle production is formulated empirically based on the data of direct observations by accelerator and cosmic-ray experiments at 10 12 ∼ 10 14 eV. The formulated distri-bution indicates violation of the Feynman scaling law, which was shown to be valid in low energy region of ≤ 10 12 eV. That is, the particle density is suppressed in the forward re-gion and enhanced in the central region, compared with the distribution of the Feynman scaling law. Consequences of the formulated distribution, such as multiplicity, inelasticity, etc., are discussed at high energies of ≥ 10 15 eV by extrap-olation. The distribution is also compared with those of nu-clear interaction models which are used widely in simula-tions of accelerator and cosmic-ray experiments.
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ABSTRACT: A possibility to use an image scanner is studied for the measurement of high energy atmospheric families detected in Chacaltaya emulsion chambers. Possible methods to remove noise spots and to identify shower spots in the X-ray films applying image processing techniques are discussed. Shower-spot darkness measured using an image scanner are compared with those measured by the usual photometric method. Also discussed is tracking of shower spots in successive layers of the emulsion chambers using neural-network techniques.
Nuclear Physics B - Proceedings Supplements 151(1):240-243. · 0.88 Impact Factor
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ABSTRACT: The characteristics of hadron interactions are studied with emulsion chambers exposed at both Mt. Chacaltaya and the Pamirs. The total exposure iauthor330 m2 year. Event by event surveys on the shower configurations in a single family event were accomplished over the 75 cosmicray families in the highest energy range, i.e., visible energy greater than 500 TeV. Extraordinary characteristics of high energy shower clusters of small spread and the exotic type interactions, Centauro species, are discussed from the cosmic-ray-family phenomenological point of view.
Nuclear Physics B. 474(1):141-182.
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[show abstract]
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ABSTRACT: Structures of hadron-induced showers observed by the Pamir thick lead chambers are compared with simulations. The simulations are made for several models, VENUS, QGSJET, HDPM and the modified UA5 model, for hadron–nucleus interactions. A parameter Z, which is related to the inelasticity of hadron–Pb interactions, is defined and the Z-distribution of experimental data is compared with those of the simulations applying the same procedure of data processing to both sets of data. The Z-distribution for single-isolated hadrons is well reproduced by the models (VENUS, QGSJET and modified UA5) which give an average inelasticity –0.8, whereas that for multi hadrons is close to the HDPM model which gives a smaller inelasticity of –0.6. The difference of the characteristics between the two categories of hadron-induced showers is discussed.
Nuclear Physics B. 581:73-90.
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N. Kawasumi,
I. Tsushima,
K. Honda,
K. Hashimoto,
T. Matano,
K. Mori,
N. Inoue,
R. Ticona,
A. Ohsawa, M. Tamada,
N. Ohmori,
N. Martinic,
N. Gironda,
F. Osco,
C. Aguirre
4:104.
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N. Kawasumi,
I. Tsushima,
K. Honda,
K. Hashimoto,
T. Matano,
N. Inoue,
K. Mori,
K. Yokoi,
A. Ohsawa, M. Tamada,
N. Ohmori,
N. Martinic,
R. Ticona,
N. Gironda,
F. Osco,
C. Aguirre
1:201.
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T. Arisawa,
Y. Fujimoto,
S. Hasegawa,
K. Honda,
H. Ito, M. Tamada,
H. Fujiwara,
K. Izaki,
K. Yokoi,
V. V. Kopenkin,
A. K. Managadze,
I. V. Rakobolskaya,
T. M. Roganova,
L. G. Sveshnikova
4:136.
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Y Fujimoto,
S Hasegawa,
V V Kopenkin,
M Moriya,
H Semba, M Tamada,
K Yokoi,
A Ohsawa,
G F Fedrova,
A. K. Managadze,
I. A. Mikhailova,
E G Popova,
I. V. Rakobolskaya,
T. M. Roganova,
L. G. Sveshnikova,
O P Strogova
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C Aguirre,
H Aoki,
K Hashimoto,
K Honda,
N Inoue,
N. Kawasumi,
Y Maeda,
N J Martinic,
T Matano,
N Ohmori,
A Ohsawa,
K Shinozaki, M Tamada,
R. Ticona,
I. Tsushima,
K Yokoi
