Air-showers, bursts and high-energy families detected by hybrid experiment at Mt.Chacaltaya M.Tamada Kinki University M.Tamada ICRC2011, Beijing, 15 Aug. 2011

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 1 Faculty of Engineering, Soka University, Hachioji, Tokyo , Japan 2 Faculty of Engineering, University of Yamanashi, Kofu , Japan 3 Faculty of Science, Saitama University, Saitama , Japan 4 Faculty of Education, University of Yamanashi, kofu , Japan 5 General Education, Yonago National College of Technology, Yonago , Japan 6 Faculty of Science, Kochi University, Kochi , Japan 7 Institute for Cosmic Ray Research, University of Tokyo, Kashiwa , Japan 8 Faculty of Science and Engineering, Kinki University, Osaka , Japan N.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”, n b Emulsion chamber: atmospehric family (n ,n h,  E ,  E h ) time, theta, phi position, theta, phi time, position 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

Coupling the family with the accompanied air shower 1. List the families in one block of the emulsion chamber =5.4  0.5 deg, =17.0  1.8 deg, =0.49  0.04m Coupling rate ~ 80 % 2. List the bursts which have their centers on the concerned block 3. Correspond the families to the bursts 4. Examine the consistency of the arrival direction, position between family and air shower (CHACALTAYA)

“ Current simulation codes describe general characteristics of hybrid data ??? ” Comparison of Chacaltaya data with simulations Comparison of Chacaltaya data with simulations

Simulations EAS: CORSIKA+QGSJET01c, EPOS 1.99 etc

CORSIKA + QGSJET01c, EPOS1.99 etc. shower size : NKG-option Ecut=0.3GeV for hadrons, muons Ecut=0.003GeV for e,gamma Thinning energy = 1 GeV (fixed) E0≥10 15 eV : proton & Fe primaries with power index -2.7 : proton-dominant (~40% proton, ~15% Fe) : heavy-dominant (~15% proton, ~40% Fe) EAS above the detector Sampling : 40,000 primaries each

Atmospheric families: detection in the emulsion chamber EM-cascade : Okamoto-Shibata algorithm Hadron-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 n b GEANT4.9.2 : Hadron-shower model : QGSP Scintillator responce Sampling from approximated function n(particle,Eh,tan  which reproduce GEANT4 results Details; Poster (HE )

Hadron Calorimeter (Burst detector) Burst density (n b ) : number of particles detected in scintillation counter / 0.25 m 2  n b  n b : sum of burst density n b (max) n b (max) : maximum burst density in 32 blocks 0.25 m^2 32 blocks

Burst density by GEANT4

Selection of the events Chacaltaya: 1037 events 62 events with family ( n  ≥2TeV)≥5 ) Ne ≥ 10 6 n b (max) ≥ 10 4 n_blk(n b ≥100) ≥ 10 R_AS_Bs ≤ 1m Ne ≥ 10 6 n b (max) ≥ 10 4 n_blk(n b ≥100) ≥ 10 R_AS_Bs ≤ 1m

Air-shower Ne, age Burst  n b, n b (max) Family  E, n , nh, R

Characteristics of air-showers and families

Ne -  E 

 E  /Ne 10^6 ≤ Ne < 10^7 10^7 ≤ Ne < 10^8

Characteristics of air-showers and bursts

Ne – n b (max) Ne – n b (max) proton Fe

Distribution of n b (max), n b (max)/Ne

Distribution of n b (max)/Ne 10^6 ≤ Ne < 10^7 10^7 ≤ Ne < 10^8

Characteristics of Burst and families

distance between burst center & family center distance between burst center & family center

n b (max) – family energy n b (max) – family energy

n b (max) – average family energy

n b (max) – family energy n b (max) – family energy 10^6 ≤ Ne < 10^7 10^7 ≤ Ne < 10^8

Estimation of family energy No systematic under- or over-estimation !

n b (max),  n b   interaction energy less sensitive to  production spectra, because of low threshold energy (~1GeV)  E  /n b (max),  n b : very sensitive to production spectra sensitive to  production spectra, because of high threshold energy (~1TeV) Bmax distribution agrees with simulations E :E :E :E :

average family energy in the events with large burst-size is much smaller than expectation strong energy dissipation strong energy dissipation ✔ some changes in interaction model ? treatment of p-, nucleus-Air interaction ? treatment of p-, nucleus-Air interaction ? ✔ increasing p-Air cross-section ? ✔ increasing/decreasing inelasticity ? change of chemical doesn’t work ! change of chemical composition doesn’t work !

summary 1. 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 – n b (max) : There are many events which accompany larger burst in the EAS of larger size. Heavy (Ne<10^7) Proton (Ne≥10^7) No model can describe 3. n b (max)-  E  : No model can describe characteristics of burst-triggered families. strong energy dissipation 4. Chacaltaya experimental data indicates strong energy dissipation in multiparticle production. ( changes in particle production, nucleus-Air int., p-Air cross-section, inelasticity, etc. )

relative intensity of families, relative intensity of families, bursts and EAS relative intensity of families, relative intensity of families, bursts and EAS 10^6 ≤ Ne < 10^8

Air-showers with burst (CORSIKA/QGSJET) Air-showers with families (CORSIKA/QGSJET) proton-dominant composition

Air-showers with burst (CORSIKA/QGSJET) Air-showers with families (CORSIKA/QGSJET) heavy-dominant composition

Ne – average n b (max) Ne – average n b (max)

Ne – burst size Ne – burst size

n b (max) – lateral spread of family n b (max) – lateral spread of family Emin= ２ TeV

distribution of  n b,  n b /Ne distribution of  n b,  n b /Ne

Ne ~ E 0 Family Burst size ~ E INT Family – burst : strong correlation Family – Ne : weak correlation

 E  burst size  E  burst size > family Burst (hadron component)  E  <  E  burst  Eh) burst  Eh) ≈ TeV GeV

an example of burst data an example of burst data Chacaltaya experiment

an example of burst data an example of burst data Chacaltaya experiment

simulated burst data : proton-primary

simulated burst data : Fe-primary

burst size – family energy burst size – family energy

burst size – average family energy

lateral distribution of burst

Ne -