g kornakov ea smultivariate analysis
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Detecting EAS with TRASGOs-a simulation-
G. Kornakov
February, 2010, Santiago de Compostela
Extensive air shower (EAS)
● How does an EAS occur? -High energy primary cosmic rays interact at the high atmosphere with production of billions of secondaries and shower formation
● Why are they interesting?-Astroparticle Physics:
– Where do they come from?
– How are they accelerated?
– How do they propagate?
– and many other...
-very high energy (up to 102 0 eV), -understanding of formation process
The knee region
Knee
1 Partícle/m2-y
1 Partícle/km2-y
1 Partícle/km2-y
EAS statistics in knee region
The scatter plot of the average logarithm of the nuclear mass number of the primary cosmic rays versus energy clearly shows the need for more input from accelerators.
[CCOU02]
Mass of the primary cosmic ray vs energy measured in different experiments
EAS simulation
Code: AIRES
Simulations characteristics:
-energy: 101 5 eV (Knee region) -primary particles: P,C,Fe,Gammas
-depth of first interaction:30g/cm2
-number of simulations: 100 for each case.-height of measurement plane: 1400 m
Extensive showers detection on Earth surface
Variables simulated
● x,y,● θ,φ● time of arrival● energy● height of production
of secondary part.● id. of the secondary
particle
EAS simulation
EAS simulation
e μ
Some results
EAS simulationSome results
e μ
Difference between azimuthal angles of electrons and muons vs time φφ
time
time
e μ
time
θ
time
r
r
θ
EAS simulationSome results
Lateral distribution in a EAS induced by proton
Lateral distribution of μ+e at different primary energies
~30m
~90m~200m
R=5particles/m2
R~30m for 101 5ev proton
110
8
6
12
11
9 7
13
3
2
5
4
R
We have started to analyse the answer of a single detector at different distances from the shower core:We assumed S=1m2 detectors
EAS simulation
RESULTS (time of arrival)
Iron
Carbon
0m R/2~15 m R ~30m
0m R/2~15 m R ~30m
Proton
Gamma
RESULTS (time of arrival)
RESULTS (zenithal angle)
0m R/2~15 m R ~30m
Iron
Carbon
0m R/2~15 m R ~30m
Proton
Gamma
RESULTS (zenithal angle)
RESULTS (Azimuthal angle in one detector)
Proton Gamma
Iron Carbon
NEXT STEPS
To define some secondary observables
● Number of particles <N>, <Ne>,<Nμ>● Arrival Times: <T><Te><Tμ>● Th <Th> and σ(Th) for e and μ at t=5ns,
t=10ns, t=20ns.● <Ph> and σ(Ph) as a function of position
Analyse their behaviour, their correlations, their
clusters...
One dream
Why multivariate analysis?
● A lot of information spread out in many observable variables (many dimensions problem)
● Some variables are strongly correlated and dependent on the primary cosmic ray characteristics (energy, mass, direction)
● Many multivariate techniques developed recently and not yet commonly used in astroparticle physics: clusters analysis, PAC analysis …
Problems we expect:● High fluctuations in different EAS from the same primary● High statistical fluctuations inside a single shower
Hope:● To find some hidden relationship among all the observables informing
us about the properties of the primitive cosmic ray
Still a lot of work
Acknowledgments
especially want to thank R.Vázquez for his help with the simulations
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