Announcement of UHECR
symposium in Nagoya, Japan
• 10-12 December
• Visit http://uhecr2010.icrr.u-tokyo.ac.jp/ for detail
• 15-Oct ; abstract deadline
– Mainly invited talks and contribution posters
– Some contributions may be selected for oral presentations
• 12-Nov; registration deadline
• Contents
–
–
–
–
Highlights from PAO, HiRes, TA and future plan
Accelerator results; AirFly, TA ELS, LHCf
Acceleration, Propagation, Multi messenger astrophysics
Panel discussions on technique, UHECR origin, interaction
First Results of LHCf;
Very Forward Particles at LHC Collision
Takashi SAKO
(Solar-Terrestrial Environment Laboratory,
Nagoya University, Japan)
for the LHCf Collaboration
ICATPP Conference, Villa Olmo, Como, Italy, 7-8 October 2010
UHECR and Hadron Interaction
• Recent excellent observations by PAO, HiRes
and TA, but still puzzling in the UHECR origin
• Uncertainty in hadron interaction affects in
– Prediction of Xmax
– SD observations
• Cross sections of very
forward particle emission
at as high as possible
energy is indispensible
=> LHC forward (LHCf) experiment
The LHCf Collaboration
K.Fukatsu, Y.Itow, K.Kawade, T.Mase, K.Masuda,
Y.Matsubara, G.Mitsuka, K.Noda, T.Sako, K.Suzuki, K.Taki
Solar-Terrestrial Environment Laboratory, Nagoya University, Japan
K.Yoshida
Shibaura Institute of Technology, Japan
K.Kasahara, M.Nakai, Y.Shimizu, T.Suzuki, S.Torii
Waseda University, Japan
T.Tamura
Kanagawa University, Japan
Y.Muraki
Konan University
M.Haguenauer
Ecole Polytechnique, France
W.C.Turner
LBNL, Berkeley, USA
O.Adriani, L.Bonechi, M.Bongi, R.D’Alessandro, M.Grandi,
H.Menjo, P.Papini, S.Ricciarini, G.Castellini
INFN, Univ. di Firenze, Italy
A.Tricomi
INFN, Univ. di Catania, Italy
J.Velasco, A.Faus
IFIC, Centro Mixto CSIC-UVEG, Spain
D.Macina, A-L.Perrot CERN, Switzerland
Experimental Set-up
LHCf Detector(Arm#1)
ATLAS
140m
LHCf Detector (Arm#2)
96mm
Protons
Charged particles (+)
Neutral particles
Beam pipe
Charged particles (-)
√s=14TeV proton collision = 1017eV in the lab. frame
LHCf Detectors
＊Imaging sampling shower calorimeters
＊Two independent calorimeters in each detector (Tangsten 44r.l.,
1.7λ, sample with plastic scintillators)
Arm#1 Detector
20mmx20mm+40mmx40mm
4 XY SciFi+MAPMT
Arm#2 Detector
25mmx25mm+32mmx32mm
4 XY Silicon strip detectors
ATLAS & LHCf
Expected Results at 14 TeV Collisions
(assuming 0.1nb-1 statistics)
Detector response
not considered
Summary of Operations in 2009 and 2010
With Stable Beam at 900 GeV
Total of 42 hours for physics
About 105 showers events in Arm1+Arm2
With Stable Beam at 7 TeV
Total of 150 hours for physics with different setups
Different vertical position to increase the accessible kinematical range
Runs with or without beam crossing angle
~ 4·108 shower events in Arm1+Arm2
~ 106 p0 events in Arm1+Arm2
Status
Completed program for 900 GeV and 7 TeV
Removed detectors from tunnel in July 2010
Post-calibration beam test in October 2010
Upgrade to more rad-hard detectors to operate at 14TeV in 2013
TeV Gamma not from Crab
but Underground!
Event sample measured by Arm2 at 30 March 2010
!
Particle Identification
A transition curve for Gamma-ray
A transition curve for Hadron
Thick for E.M. interaction (44X0) Thin for hadronic interaction(1.7l)
L90% @ 40mm cal. of Arm1
Definition of L90%
MC (QGSJET2)
Data
Gamma-ray like
Hadron like
Criteria for gamma-rays
16 r.l. + 0.002 x SdE
• L90%; longitudinal position containing 90%
of the sum of the shower particles.
• PID bias, Neural Net are in investigation
Energy Spectra at 900GeV
Gamma-ray like
preliminary
Arm1 Hadron like
Only statistical
errors are shown
Gamma-ray like
preliminary
Hadron response
under study
preliminary
Arm2Hadron like
preliminary
Acceptance is different in two arms
Normalized by number events
Response for hadrons and systematic error are under study.
Measured Spectra at 7TeV
Gamma-ray like
preliminary
Arm1Hadron like
preliminary
Gamma-ray like
preliminary
Arm2
Hadron like
preliminary
Very high statistics !! only 2% of all data
Comparisons with MC will be available soon
Careful study of systematic error is ongoing
Neutral Pions
An example of event (Arm2)
25mm
Energy spectrum (Arm2)
32mm
preliminary
Silicon strip-X view
1(E1)
R
R
=
140 m
140m
2(E2)
Reconstructed mass (Arm2)
ΔM/M=2.3%
M/M=2.3%

I.P.1
• Pi0’s are a main source of electromagnetic
secondaries in high energy collisions.
• The mass peak is very useful to confirm the
detector performances and to estimate the
systematic error of energy scale.
preliminary
preliminary
14TeV in 2013;
Not only highest energy, but energy dependence…
SIBYLL
QGSJET2
7 TeV
10 TeV
14 TeV (1017eV@lab.)
7 TeV
10 TeV
14 TeV
Secondary gamma-ray spectra in p-p collisions
at different collision energies (normalized to
the maximum energy)
SIBYLL predicts perfect scaling while QGSJET2
predicts softening at higher energy
Qualitatively consistent with Xmax prediction
Summary
• LHCf has successfully completed operation at
900GeV and 7TeV collisions at LHC
• Unprecedented quality of data allows to test
existing hadron interaction models and helps
to construct new models
• Operation at 14TeV collisions in 2013 will set
more strict limits on the hadron interaction
models to extrapolate into higher energy
Analysis of the first result will be finalized soon
Announcement of UHECR
symposium in Nagoya, Japan
• 10-12 December
• Visit http://uhecr2010.icrr.u-tokyo.ac.jp/ for detail
• 15-Oct ; abstract deadline
– Mainly invited talks and contribution posters
– Some contributions may be selected for oral presentation
• 12-Nov; registration deadline
• Contents
–
–
–
–
Highlights from PAO, HiRes, TA and future plan
Accelerator results; AirFly, TA ELS, LHCf
Acceleration, Propagation, Multi messenger astrophysics
Panel discussions on technique, UHECR origin, interaction
Backup
Open Issues on HECR spectrum
AGASA Systematics
Total
±18%
Hadr Model
~10%
(Takeda et al., 2003)
M Nagano
New Journal of Physics 11 (2009) 065012
Depth of the max of
the shower Xmax in
the atmosphere
HiRes
AUGER
IP1,ATLAS
Arm2
η
Arm1
Shadow of beam pipes
between IP and TAN
8.4
8.7
∞
∞
@ 140mrad crossing angle
Transverse projection of Arm#1
@ zero crossing angle
Pseudo-rapidity Coverage
ATLAS
Energy spectra and
Transverse momentum distribution of
• Gamma-rays (E>100GeV,dE/E<5%)
• Neutral Hadrons (E>a few 100 GeV, dE/E~30%)
• Neutral Pions (E>700GeV, dE/E<3%)
at psudo-rapidity range >8.4
Multiplicity@14TeV
Low multiplicity !!
LHCf
Energy Flux @14TeV
High energy flux !!
simulated by DPMJET3
Eγ – PTγ Correlation plot
140
Beam crossing angle
h search
p0 Candidate
h Candidate
preliminary
• h/p0 ratio vary a lot among different interaction models.
A good handle to probe the hadron interaction models
• Another calibration point for more robust energy scale
Beam test at SPS
Detector
Energy Resolution
for electrons with 20mm cal.
- Electrons 50GeV/c – 200GeV/c
- Muons 150GeV/c
- Protons 150GeV/c, 350GeV/c
Position Resolution (Silicon)
Position Resolution (Scifi)
σ=172μm
for 200GeV
electrons
σ=40μm
for 200GeV
electrons
Accumulated Events in 2010
108 events!
LHCf removal