Y.Itow, LHCf Forward physics results LHC-CR2013 @ 11Feb2013 LHCf forward physics results Yoshitaka Itow STE Lab / Kobayashi-Maskawa Inst. Nagoya University and on behalf of the LHCf collaboration “LHC-CR 2013” Feb 11-12, 2013, CERN 1
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 The LHCf collaboration The LHCf collaboration T.Iso, Y.Itow, K.Kawade, Y.Makino, K.Masuda, Y.Matsubara, E.Matsubayashi, G.Mitsuka, Y.Muraki, T.Sako Solar-Terrestrial Environment Laboratory, Nagoya Univ. H.Menjo Kobayashi-Maskawa Institute, Nagoya Univ. K.Yoshida Shibaura Institute of Technology K.Kasahara, T.Suzuki, S.Torii Waseda Univ. T.Tamura Kanagawa University M.Haguenauer Ecole Polytechnique, France W.C.Turner LBNL, Berkeley, USA O.Adriani, L.Bonechi, M.Bongi, R.D’Alessandro, M.Grandi, P.Papini, S.Ricciarini, G.Castellini INFN, Univ. di Firenze, Italy K.Noda, A.Tricomi INFN, Univ. di Catania, Italy A-L.Perrot CERN, Switzerland ~30 physicists from 5 countries 2
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 The LHCf detectors 140m calorimeter calorimeter IP1 γ Arm1 Arm2 n π 0 Front Counter Front Counter Arm1 Arm2 44X 0 , 1.6 λ int 16 tungsten + pl.scinti. layers 16 tungsten + pl.scinti. layers 20mmx20mm+40mmx40mm 25mmx25mm+32mmx32mm 3 4 SciFi tracking layers 4 Silicon strip tracking layers
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 What LHCf measures ① Inelastic cross section If large σ rapid development If small σ ④ 2ndary interactions deep penetrating ② Forward energy spectrum nucleon, π If softer shallow development If harder deep penetrating ③ Inelasticity k= 1-p lead /p beam If large k ( π 0 s carry more energy) rapid development If small k ( baryons carry more energy) deep penetrating 4 (relevant to N µ )
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Impact of forward spectra on shower development X F = E/Etot Half of shower Measurement at particles comes very forward region is needed from large X F γ 5
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 LHCf p T acceptance N 1 pT (GeV/c) η =8.40 θ η =8.77 [ μ rad] 0 310 2000 0 Energy (GeV) 0 NxE 1 Projected pT (GeV/c) edge of beam η =8.40 pipe η =8.77 0 6 0 2000 Energy (GeV)
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 LHCf single γ spectra at 7TeV 0.68 (0.53)nb -1 on 15May2010 DPMJET 3.04 QGSJETII-03 SIBYLL 2.1 EPOS 1.99 PYTHIA 8.145 Magenta hatch: Stat errors of MC Gray hatch : Sys+stat errors 8.81< η <8.99 η >10.94 8.81< η <8.99 η >10.94 Arm1 8.81< η <8.99 η >10.94 PLB 703 (2011) 128-134 Arm2 � None of the models agree with data 7 � Data within the range of the model spread
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 LHCf single γ spectra at 900 GeV PLB 715 (2012) 298-303 May2010 900GeV data ( 0.3nb-1 , 21% uncertainty not shown ) DPMJET 3.04 QGSJETII-03 SIBYLL 2.1 EPOS 1.99 PYTHIA 8.145 η >10.15 8.77 < η <9.46 8.77 < η <9.46 η >10.15 MC/Data 6 6 8.77 < η <9.46 5 5 4 4 3 3 2 2 1 1 η >10.15 8 50 450 50 450 E(GeV) E(GeV)
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Comparison of Data/MC ratio at two energies DPMJET 3.04 QGSJETII-03 SIBYLL 2.1 EPOS 1.99 PYTHIA 8.145 MC/Data MC/Data High η low η 2 2 7TeV 1 1 MC/Data MC/Data 900GeV 2 2 1 1 9
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 7TeV X F spectra for single γ : 0.9TeV 900GeV/ 7TeV comparison (sys error not included) Arm1-Data Arm1-EPOS Preliminary Preliminary X F X F � Comparing X F for common P T region at two collision energies. 10 � Less root-s dependence of P T for X F ?
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 LHCf 7TeV π 0 analysis Type-II Type-I Type-I σ M =3.7% 1 1 PT π 0 (GeV/c) Type-II 0 0 3500 0 E π 0 (GeV) 0 E π 0 (GeV) 3500 11
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 LHCf π 0 P T spectra at 7TeV PRD 86 (2012) 092001 DPMJET 3.04 QGSJETII-03 SIBYLL 2.1 EPOS 1.99 PYTHIA 8.145 0 P T [GeV] 0.6 0.6 0.6 0 P T [GeV] 0 P T [GeV] 12 0.6 0.6 0.6 0 P T [GeV] 0 P T [GeV] 0 P T [GeV]
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 LHCf π 0 P T spectra at 7TeV (data/MC) DPMJET 3.04 QGSJETII-03 SIBYLL 2.1 EPOS 1.99 PYTHIA 8.145 EPOS gives the best agreement both for shape and yield. MC/Data 0 P T [GeV] 0.6 0 P T [GeV] 0.6 0 P T [GeV] 0.6 MC/Data 13 0 P T [GeV] 0.6 0 P T [GeV] 0.6 0 P T [GeV] 0.6
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 14
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Average P T of π 0 1. Thermodynamics 1. Thermodynamics � Comparison w/ UA7@630GeV (Hagedron, Riv. Nuovo Cim. 6:10, 1 (1983)) (Hagedron, Riv. Nuovo Cim. 6:10, 1 (1983)) � Extend to higher η regions � Less energy dependence of <PT>? 15
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Current and future activity � Forward neutron spectra � Inelasticity � Cold nuclear effect � LHC p-Pb � Energy dependence � 14TeV at LHC, 0.5TeV pp at RHIC � Nuclear dependence � p-A, A-A at RHIC, and future LHC ? � Feedback to air showers 16
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Nuclear effects for very forward region � Air showers take place via p-N or Fe-N collisions ! � Nuclear shadowing, final state interaction, gluon saturations � Nuclear modification factor at 0 degree may be large. Phys. Rev. Lett. 97 (2006) 152302 p-p QGSJET II-04 p-N All η η s p-Pb 8.81< η <8.99 η >10.94 17 Courtesy of S. Ostapchenko
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 LHCf p – Pb runs at √ s NN = 4 TeV (Jan 2013) Pb IP1 IP2 IP8 Arm2 p � 2013 Jan / a month of p-Pb opportunity. � Install only Arm2 at one side (Si good for multiplicity) � Data both at p-side and Pb-side � Common pre-scaled trig. w/ ATLAS γ for centrality tagging p-remnant #Events (Millions) side Pb-remnant side Beam reversal 18 20 Jan 27 Jan. 01 Feb.
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 LHCf p-Pb runs A high multiplicity event at Pb-side Shower incident position at p-side 19
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Future p-N and Fe-N in LHC ? � LHC 7TeV/Z p-N and N-N collisions realize the laboratory energy of 5.2x10 16 eV and 3.6x10 17 eV, respectively (N: Nitrogen) � Suggestions from the CERN ion source experts: � LHC can in principle circulate any kind of ions, but switching ion source takes considerable time and manpower � Oxygen can be a good candidate because it is used as a ‘support gas’ for Pb ion production. This reduces the switching time and impact to the main physics program at LHC. � According to the current LHC schedule, the realization is not earlier than 2020. � New ion source for medical facility in discussion will enable even Fe-N collisions in future 20
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Summary � LHCf provides dedicated measurements of neutral particles at 0 deg to cover most of collision energy flow. � E spectra for single gamma at 7TeV and at 900GeV. Agreement is “so-so”, but none of models really agree. � PT spectra for 7TeV π 0 . EPOS gives nice agreement. � Forward neutron analysis is under going � 2004 LHC p-Pb run successfully (almost ) done to study cold nuclear effect at 0 degree. � Future � Revisit “14TeV” at ~2014 with a rad-hard detector. � Possible future RHIC run is under discussion. � Possible LHC light ion runs is under discussion. 21
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 International Workshop on “High-energy scattering at zero degree" 2 nd - 4 th March, 2013 KMI, Nagoya University http://www.gcoe.phys.nagoya-u.ac.jp/hesz2013 Organizing committee � Diffraction and very forward p-p and p-A scatterings � Forward and ultra peripheral A-A scatterings Yoshitaka Itow (Nagoya) � Spin asymmetry at very forward in polarized p-p Kazunori Itakura (KEK) scatterings Yuji Goto (Riken) Takashi Sako (Nagoya) � High energy cosmic ray interaction models Kenta Shigaki (Hiroshima) � QCD aspects in very forward scattering Kiyoshi Tanida (SNU) 22 Yuji Yamazaki (Kobe)
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Backup 23
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Calorimeter performance � Gamma-rays (E>100GeV, dE/E<5%) � Neutral Hadrons (E>a few 100 GeV, dE/E~30%) � Neutral Pions (E>700GeV, dE/E<3%) � Shower incident position (170 µ m / 40 µ m for Arm1/Arm2) π 0 γ -like Had-like 24
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 Very forward : Majority of energy flow ( √ s=14TeV) M ultiplicity Energy Flux All particles neutral 8.4 < η < ∞ Most of the energy flows into very forward ( Particles of X F > 0.1 contribute 50% of shower particles ) 25
Y.Itow, LHCf Forward physics results LHC-CRS2013 @ 11Feb 2013 LHCf calorimeters 290mm Arm#1 Detector 90mm Arm#2 Detector 26
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