air-showers, bursts and high-energy families detected by hybrid experiment at mt.chacaltaya m.tamada...
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Air-showers, bursts and high-Air-showers, bursts and high-energy families detected by hybrid energy families detected by hybrid
experiment at Mt.Chacaltayaexperiment at Mt.Chacaltaya
Air-showers, bursts and high-Air-showers, bursts and high-energy families detected by hybrid energy families detected by hybrid
experiment at Mt.Chacaltayaexperiment at Mt.Chacaltaya
M.TamadaM.Tamada
Kinki UniversityKinki UniversityM.TamadaM.Tamada
Kinki UniversityKinki University
ICRC2011, Beijing, 15 Aug. 2011
H.Aoki^1, K.Honda^2, N.Inoue^3, N.Kawasumi^4, N.Ochi^5, N.Ohmori^6, H.Aoki^1, K.Honda^2, N.Inoue^3, N.Kawasumi^4, N.Ochi^5, N.Ohmori^6, A.Ohsawa ^7, M.Tamada^8, T.Yamasaki^8 A.Ohsawa ^7, M.Tamada^8, T.Yamasaki^81 Faculty of Engineering, Soka University, Hachioji, Tokyo 192-8577, Japan2 Faculty of Engineering, University of Yamanashi, Kofu 400-8510, Japan3 Faculty of Science, Saitama University, Saitama 388-8570, Japan4 Faculty of Education, University of Yamanashi, kofu 400-8510, Japan5 General Education, Yonago National College of Technology, Yonago 683-8502, Japan6 Faculty of Science, Kochi University, Kochi 780-8520, Japan7 Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan8 Faculty of Science and Engineering, Kinki University, Osaka 577-8502, Japan
N.Martinic, R.TiconaN.Martinic, R.Ticona Insitute de Investigaciones Fisicas, Universidad Mayor de San Andres, La Paz, Bolivia
(Mt. Chacaltaya, 5200m, Bolivia)
45 scintillation counters
32 blocks
emulsion chamber
hadron calorimeter (burst detector)
EAS-array: shower size, Ne
Hadron calorimeter: “burst density”, nb
Emulsion chamber:
atmospehric family (n,nh,E,
Eh)
time, theta, phi
position, theta, phi
time, position
primary energy
primary energy
sensitive to hadron component of the air-showers
sensitive to hadron component of the air-showers
high threshold energy (E≥2 〜4TeV): sensitive to production spectra
high threshold energy (E≥2 〜4TeV): sensitive to production spectra
“ Current simulation codes describe general
characteristics of hybrid data ??? ”
Comparison of Comparison of Chacaltaya data with Chacaltaya data with
simulationssimulations
Comparison of Comparison of Chacaltaya data with Chacaltaya data with
simulationssimulations
Simulations
EAS: CORSIKA+QGSJET01c, EPOS 1.99 etc
CORSIKA + QGSJET01c, EPOS1.99 etc.
shower size : NKG-optionEcut=0.3GeV for hadrons, muonsEcut=0.003GeV for e,gamma
Thinning energy = 1 GeV (fixed)
E0≥1015eV : proton & Fe primaries with power index -2.7
: proton-dominant (~40% proton, ~15% Fe)
: heavy-dominant (~15% proton, ~40% Fe)
EAS above the detectorEAS above the detector
Sampling : 40,000 primaries each
Atmospheric families:detection in the emulsion
chamber
Atmospheric families:detection in the emulsion
chamber
EM-cascade : Okamoto-Shibata algorithmHadron-Pb int. : QGSJET01c
(e,) & hadrons in the families : E≥1TeV
• electron number ---> spot darkness• shower transition on spot darkness• fitting using standard cascade curve :T, E() showers of T > 6 c.u. : hadron-induced
Calculation of Burst-density nb
Calculation of Burst-density nb
GEANT4.9.2:
Hadron-shower model : QGSP
Scintillator responce
Sampling from approximated function n(particle,Eh,tan which reproduce GEANT4 results
Details; Poster (HE1.2 255)
Hadron Calorimeter (Burst detector)
• Burst density (nb) : number of particles
detected in scintillation counter / 0.25 m2
• nnbb : sum of burst density
• nnbb(max) (max) : maximum burst density in 32
blocks0.25 m^2
32 blocks
Selection of the eventsSelection of the events
Chacaltaya:•1037 events
• 62 events with family ( n≥2TeV)≥5 )
• Ne ≥ 106
• nb(max) ≥ 104
• n_blk(nb≥100) ≥ 10• R_AS_Bs ≤ 1m
• Ne ≥ 106
• nb(max) ≥ 104
• n_blk(nb≥100) ≥ 10• R_AS_Bs ≤ 1m
Air-shower
Ne, age
Burstnb, nb(max)
FamilyE, n, nh, R
Characteristics of air-showers and
families
Characteristics of air-showers and
families
Ne -Ne -EE
EE/Ne/Ne10^6 ≤ Ne < 10^710^6 ≤ Ne < 10^7 10^7 ≤ Ne < 10^810^7 ≤ Ne < 10^8
Characteristics of air-showers and bursts
Characteristics of air-showers and bursts
Ne – Ne – nnbb(max) (max)
protoprotonn
FFee
Distribution of nDistribution of nbb(max)/Ne(max)/Ne10^6 ≤ Ne < 10^710^6 ≤ Ne < 10^7 10^7 ≤ Ne < 10^810^7 ≤ Ne < 10^8
Characteristics of Burst and familiesCharacteristics of
Burst and families
nnbb(max) – family (max) – family energyenergy
nnbb(max) – average family (max) – average family energyenergy
average family energy in the average family energy in the events with large burst-size events with large burst-size
is much smaller than is much smaller than expectationexpectation
• strong energy strong energy dissipationdissipation
✔ ✔ somesome changes in interaction model ?changes in interaction model ? treatment of p-, nucleus-Air treatment of p-, nucleus-Air interaction ?interaction ?✔ ✔ increasing p-Air cross-section ?increasing p-Air cross-section ?✔ ✔ increasing/decreasing inelasticity ?increasing/decreasing inelasticity ?
change of chemical change of chemical composition doesn’t doesn’t work !work !
change of chemical change of chemical composition doesn’t doesn’t work !work !
summary1. Ne – E : family energy in the EAS with Ne≥10^7
is systematically smaller than that expected in proton induced EAS. Proton (Ne<10^7) Heavy (Ne≥10^7)
2. Ne – nb(max) : There are many events which accompany larger burst in the EAS of larger size. Heavy (Ne<10^7) Proton (Ne≥10^7)
3. nb(max)-E: No model can describeNo model can describe characteristics of burst-triggered families.
4. Chacaltaya experimental data indicates strong strong energy dissipationenergy dissipation in multiparticle production.
( changes in particle production, nucleus-Air int., p-Air cross-section, inelasticity, etc. )