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. )