1. LHCf: Calibration of hadron interaction models for high energy cosmic-ray physics at the LHC energy T.Mase for the LHCf collaboration Nagoya University, Solar-Terrestrial Environment Laboratory

2. 16.Nov.2009Tours2009 T.Mase2 Physics motivation of LHCf To reduce the uncertainty of hadron interaction models by using LHC accelerator LHCf measures neutral particles emitted in very forward (including zero degree) in the LHC collisions To discriminate existing interaction models and provide crucial data for future models

3. 16.Nov.2009Tours2009 T.Mase3 The LHCf collaboration Y.Itow, K.Kawade, T.Mase, K.Masuda, Y.Matsubara, G.Mitsuka, T.Sako, K.TakiSolar-Terrestrial Environment Laboratory, Nagoya University, Japan K.YoshidaShibaura Institute of Technology, Japan K.Kasahara, M.Nakai, S.Torii Waseda University, Japan T.TamuraKanagawa University, Japan Y.MurakiKonan University Y.ShimizuICRC, University of Tokyo, Japan M.HaguenauerEcole Polytechnique, France W.C.TurnerLBNL, Berkeley, USA O.Adriani, L.Bonechi, M.Bongi, R.D’Alessandro, M.Grandi, H.Menjo, P.Papini, S.Ricciarini, G.Castellini, A. Viciani INFN, Univ. di Firenze, Italy A.TricomiINFN, Univ. di Catania, Italy J.Velasco, A.FausIFIC, Centro Mixto CSIC-UVEG, Spain D.Macina, A-L.PerrotCERN, Switzerland

4. 16.Nov.2009Tours2009 T.Mase4 Air shower and hadron interaction model Primary cosmic rays interact with the atmospheric molecules The air shower is developed by hadron interactions and electromagnetic cascades The air shower experiments measure the secondary particles on the ground To know the primary information, we must reconstruct the shower Simulation

5. 16.Nov.2009Tours2009 T.Mase5 Energy spectrum of cosmic rays GZK cutoff; Propagation limit due to CMB absolute energy scale doesn't agree uncertainty of hadron interaction model Confirmation of the various models using the LHC is important key for the cosmic ray physics.

6. 16.Nov.2009Tours2009 T.Mase6 Experimental Overview LHCf is one of six experiments of LHC 7TeV+7TeV corresponds 1.0x10 17 eV(Lab. system) Detectors are installed at the 140m away from the Interaction Point 1 In the TAN, beam pipe is separated into two pipes, 96mm gap between these pipes Installed both sides of IP1, named Arm1 and Arm2 LHCf covers pseudorapidity  > 8.4 LHCf detector 96mm ATLAS(IP1) LHCf Detector 140m away from the interaction point TAN neutral particle absober I.P.

7. 16.Nov.2009Tours2009 T.Mase7 Schematic view of LHCf detectors Sampling & imaging calorimeters both sides of IP1 Two small tower calorimeters in both detectors (Tungsten 44r.l., 1.7λ, 16 plastic scintillator sampling layers, 4 position sensitive layers) Arm#1 Detector 20mmx20mm+40mmx40mm 4 XY SciFi+MAPMT Arm#2 Detector 25mmx25mm+32mmx32mm 4 XY Silicon strip detectors 32mm 25mm 40mm 20mm

8. 16.Nov.2009Tours2009 T.Mase8 Double arm detectors 280mm 92mm 90mm Arm#1 DetectorArm#2 Detector

9. 16.Nov.2009Tours2009 T.Mase9 Discriminate the hadron interaction models LHCf measures the neutral particles emitted in the very forward region of LHC The main targets are gamma-ray, neutron and  0 The difference between models is evaluated by shape of the spectrum Gamma Spectrum  0 Spectrum Neutron Spectrum

10. 16.Nov.2009Tours2009 T.Mase10 DOF=17  0 analysis  0 s are reconstructed from 2  Peak of the mass is seen  0 (generated by DPMJET3) mass is reconstructed by Full MC Other interaction models generated by rather simple MC  2 test shows that LHCf can discriminate the models Peak= 134 MeV σ= 4.9 MeV 22 Prob. QGSJET-II224.9<10 -20 SIBYLL49.16x10 -5

11. 16.Nov.2009Tours2009 T.Mase11 Schedule of LHCf LHCf will take data for all energies 0.45 7 5 3 ? Beam Energy (TeV) Lab. Energy (eV) 1.0x10 17 5.1x10 16 1.8x10 16 4.1x10 14 200920102011- 0.45 1.1 3.5 4-5 5-7 operationupgradeoperation heavy ion

12. 16.Nov.2009Tours2009 T.Mase12 Summary LHCf will measure the energy and transverse momentum of neutral particles emitted in the forward region of the LHC The physics goal is to provide the data for calibration of the hadron interaction model of cosmic ray at LHC energy LHC will start in this year and increase energy up to 7TeV and LHCf will take data for each energy LHCf can discriminate and improve the hadron interaction model Zero-degree data of gamma-rays, neutrons and  0 s The hadron interaction models can be well discreminated by using energy spectra

13. Fin.

14. 16.Nov.2009Tours2009 T.Mase14 Cosmic ray measurement X max suggest heavy primary Anisotropy suggest light primary (if accept AGN correlation) interpretation strongly depends on the hadron interaction model Confirmation of the various models using the LHC is important key for the cosmic ray physics.

15. 16.Nov.2009Tours2009 T.Mase15 Discrimination of hadron interaction model LHCf measure the neutral particle emitted in the very forward region of LHC Expected spectrum of gamma-ray is different by hadron interaction models The difference between models is evaluated by shape of the spectrum Gamma Spectrum N i data (  )=N(  E  ) is i-th bin of the energy spectrum of reference (QGSJET-II) N i model =N(E  ) is i-th bin of energy spectrum of test (QGSJET, DPMJET3 and SIBYLL)  is a normalization factor  is a scale factor  i data,  i model are statistical errors of the i-th bin DOF=67 22 Prob. QGSJET580.78 DPMJET3730.29 SIBYLL1351.7x10 -6