Testing the HiRes Detector Simulation against UHECR Data Andreas Zech ( Rutgers University) for the HiRes - Fly´s Eye Collaboration ICRC 2003 in Tsukuba
Mar 19, 2016
Testing the HiRes Detector Simulation
against UHECR DataAndreas Zech
( Rutgers University)for the HiRes - Fly´s Eye
Collaboration
ICRC 2003 in Tsukuba
HiRes CollaborationHiRes CollaborationJ.A. Bellido, R.W. Clay, B.R. Dawson,
K.M. SimpsonUniversity of Adelaide
J. Boyer, S. Benzvi, B. Connolly, C. Finley, B. Knapp, E.J. Mannel, A. O’Neil, M. Seman, S. Westerhoff
Columbia University
J. Belz, M. Munro, M. SchindelMontana State University
G. Martin, J.A.J. Matthews, M. RobertsUniversity of New Mexico
D. Bergman, L. Perera, S. Schnetzer, G.B. Thomson, A. Zech
Rutgers University
N. Manago, M. SasakiUniversity of Tokyo
T. Abu-Zayyad, J. Albretson, G. Archbold, J. Balling, K. Belov, Z. Cao, M. Dalton,
A. Everett, J. Girard, R. Gray, W. Hanlon, P. Hüntemeyer, C.C.H. Jui, D. Kieda, K. Kim, E.C. Loh, K. Martens, J.N. Matthews, A. McAllister, J. Meyer, S.A. Moore, P. Morrison, J.R.
Mumford, K. Reil,R. Riehle, P. Shen, J. Smith, P. Sokolsky, R.W.
Springer, J. Steck, B.T. Stokes, S.B. Thomas, T.D. Vanderveen,
L. WienckeUniversity of Utah
J. Amann, C. Hoffman, M. Holzscheiter, L. Marek, C. Painter, J. Sarracino, G. Sinnis, N. Thompson, D. TupaLos Alamos National
Laboratory
The HiRes FADC Detector (HiRes-2)
The newer one of the 2 HiRes air fluorescence detectors 2 rings with 21 mirrors each Located on Camel’s Back Ridge in Dugway (Utah) Started taking data in fall 1999
The HiRes FADC Detector (HiRes-2)
256 photomultiplier tubes per mirror. Flash ADC electronics record at a frequency of 10 MHz.
The Role of Monte Carlo Simulations in the HiRes
ExperimentWe need M.C. to calculate the acceptance of our detectors for the flux measurement:
M.C. is also a powerful tool for resolution studiesand for tests of our reconstruction programs. This requires a simulation program that describes the shower development and detector response as realistically as possible. We want our code to simulate events under
the exact data-taking conditions.
HiRes Simulation Programs
HiRes FADC detector Monte Carlo choose energy & composition from measured
distributions; choose random geometry pick one shower from the library and scale it to energy choose trigger & atmosphere from databases generate detector response for this shower
CORSIKA & QGSJet Generation of Air Showers G.H. Fits to the Shower
Profiles
Shower Library one entry for each shower: energy primary particle zenith angle depth of first interaction 4 G. H. fit parameters
Database with Trigger Conditions Nightly ontime Trigger Gains Trigger Logic Dead Mirrors
Atmospheric Database Hourly Information about the Aerosol Profile of the Atmosphere from Laser Shots.
MC Output File in the same format as
real data
M.C. Input Energy & Composition
The composition is chosen from our HiRes Stereo and HiRes/MIA measurement.
The Fly’s Eye Stereospectrum is used as aninput for the M.C.
CORSIKA Shower Library (proton & iron)
Gaisser-Hillas fit to the shower profile:
Fit parameters scale with primary energy:
Adding Noise to the M.C.Ambient light level (low amplitude) can be measured from the width of the FADC pedestals.
Additional sky noise (high amplitude) is added to the M.C. to get agreement with data of a certain period.
FADC counts in all trigger channelsblack: datared: M.C.total noise tubes distribution
black: datared: M.C.
A few Data / Monte Carlo Comparisons
or: Testing how well we understand our experiment ...
HiRes-2 data shown from 12/99 until 09/01. ~ 556 Hours of good weather data. average atmosphere used for consistency with
HiRes-1. Statistics:
– rec. geometry: 6309 events– after all cuts: 2274 events
M.C. : ~ 4 x data statistics
Signal tubes / χ of linear time fit
2
Light per Track Length / Čerenkov Fraction
Rp / Rp Resolution
Energy / Energy Resolution
HiRes-2 Exposure
Flux:
HiRes-2 Energy Spectrum
HiRes-2 data from 12/’99 until 09/’01
HiRes Mono Energy Spectra
HiRes-1 data from 06/’97 until 02/’03
HiRes-2 data from 12/’99 until 09/’01
Conclusions Our data analysis relies on a realistic M.C.
simulation for the aperture calculation and for resolution studies.
We have generated air showers and detector response for the HiRes FADC detector under the exact data-taking conditions.
We have tested our simulation successfully against data taken by HiRes-2.
Our M.C. simulation provides a realistic and detailed model of our experiment.
HiRes and Fly’s Eye Stereo
HiRes-1
HiRes-2
Fly’s Eye Stereo
HiRes and Fly’s Eye Stereo
HiRes-1
HiRes-2
Fly’s Eye Stereo
Energy rescaled by - 6 %
HiRes and HiRes / MIA
HiRes-1
HiRes-2
HiRes Prototype & MIA muon array ( hybrid )
HiRes and AGASA
HiRes-1
HiRes-2
AGASA
Cuts Track length Number of signal
tubes Zenith angle Track angle Psi angle Error in Psi angle Pseudodistance
Good weather conditions
Time tangent fit Chi Squared
Profile fit Chi Squared
Čerenkov light fraction
‘Bracketing’ cut
Čerenkov Light Simulation
The Longitudinal Profile calculated in the M.C. is in good agreement with results from
CORSIKA.
Lateral Profile: - we fit CORSIKA density
profiles to the sum of 3 exponentials.
- fits are parametrized with zenith angle and distance between detector and Xmax.
black: CORSIKA long. Čerenkov profile vs. atmospheric depthred: our M.C. simulation
red: CORSIKA lateral Čerenkov density vs. radial distance in meterblack: our fit using the sum of 3 exp.
Shower Geometry
Pseudodistance / Angle of shower axis in shower-detector plane