Announcement of UHECR symposium in Nagoya, Japan December Visit for detailhttp://uhecr2010.icrr.u-tokyo.ac.jp/ 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

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 The LHCf Collaboration

96mm Experimental Set-up ATLAS 140m LHCf Detector(Arm#1) LHCf Detector (Arm#2) √s=14TeV proton collision = eV in the lab. frame Charged particles (+) Neutral particles Beam pipe Protons Charged particles (-)

LHCf Detectors Arm#1 Detector 20mmx20mm+40mmx40mm 4 XY SciFi+MAPMT Arm#2 Detector 25mmx25mm+32mmx32mm 4 XY Silicon strip detectors ＊ Imaging sampling shower calorimeters ＊ Two independent calorimeters in each detector (Tangsten 44r.l., 1.7λ, sample with plastic scintillators)

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  10 5 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  4·10 8 shower events in Arm1+Arm2  10 6  0 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 40mm cal. of Arm1 MC (QGSJET2) Data Preliminary Thick for E.M. interaction (44X 0 ) Thin for hadronic interaction(1.7 ) A transition curve for Gamma-rayA transition curve for Hadron Definition of L90% Criteria for gamma-rays 16 r.l x  dE Gamma-ray like L90%; longitudinal position containing 90% of the sum of the shower particles. PID bias, Neural Net are in investigation Hadron like

Energy Spectra at 900GeV preliminary Gamma-ray like Hadron like Arm1 Arm2 Acceptance is different in two arms Normalized by number events Response for hadrons and systematic error are under study. Hadron response under study Only statistical errors are shown

Measured Spectra at 7TeV preliminary Gamma-ray like Hadron like Arm2 preliminary Gamma-ray like Hadron like Arm1 Very high statistics !! only 2% of all data Comparisons with MC will be available soon Careful study of systematic error is ongoing

Neutral Pions ΔM/M=2.3% Energy spectrum (Arm2) preliminary An example of event (Arm2) 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. 25mm 32mm Silicon strip-X view  M/M=2.3% Reconstructed mass (Arm2) preliminary I.P.1   1 (E 1 )  2 (E 2 ) 140m R

14TeV in 2013; Not only highest energy, but energy dependence … 7 TeV 10 TeV 14 TeV (10 17 SIBYLL 7 TeV 10 TeV 14 TeV QGSJET2 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 Note: detector aperture taken into account (biased)

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 December Visit for detailhttp://uhecr2010.icrr.u-tokyo.ac.jp/ 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

AGASA Systematics Total ±18% Hadr Model ~10% (Takeda et al., 2003) AGASA Systematics Total ±18% Hadr Model ~10% (Takeda et al., 2003) Open Issues on HECR spectrum M Nagano New Journal of Physics 11 (2009) Depth of the max of the shower X max in the atmosphere AUGER HiRes

neutral beam axis η ∞ 8.7 Shadow of beam pipes between IP and TAN IP1,ATLAS Arm1 Arm2 Transverse projection of Arm#1 ∞ zero crossing  rad crossing angle

Pseudo-rapidity Coverage Energy spectra and Transverse momentum distribution of Low multiplicity !! High energy flux !! simulated by DPMJET3 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 ATLAS LHCf

E γ – P T γ Correlation plot Detectable events 140 Beam crossing angle

 search  0 Candidate  Candidate    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 preliminary

Beam test at SPS Energy Resolution for electrons with 20mm cal. Position Resolution (Scifi) Position Resolution (Silicon) Detector p,e-,mu σ=172 μm for 200GeV electrons σ=40 μm for 200GeV electrons - Electrons 50GeV/c – 200GeV/c - Muons 150GeV/c - Protons 150GeV/c, 350GeV/c

Accumulated Events in events!LHCf removal