Large Hadron Collider forward (LHCf) - PowerPoint PPT Presentation

実験の概要とこれまでの測定結果 Large Hadron Collider forward (LHCf) 牧野 友耶 名古屋大学 CR 研 YMAP 若手研究会 , ICRR

実験の概要とこれまでの測定結果 • UHECRs 観測とハドロン相互作用モデル起因の不定性 • Large Hadron Collider forward ( LHCf ) 実験 • これまでの測定結果 ( p-p/p-Pb, √ s=900 GeV - 7 TeV) • 新型検出器開発 • 13 TeV 測定と Preliminary results Large Hadron Collider forward (LHCf) 牧野 友耶 名古屋大学 CR 研 YMAP 若手研究会 , ICRR

相互作用モデル 用いられる複数存在するハドロン 空気シャワーシミュレーションで UHECR とハドロン相互作用モデルの問題 850 <X max > [gm/cm 2 ] Data QGSJETII − 03 QGSJET − 01c SYBILL 2.1 800 Proton 750 Iron 700 R.U. Abbasi et al., Astroparticle Physics 64 (2015) 650 18.5 19 19.5 20 Energy log 10 (E/eV) • 空気シャワー実験が UHECRs の観測数を増やしつつある • TAx4, Auger prime によりさらに高統計が期待 • 相互作用モデル起因の不定性が化学組成決定のボトルネック 3

Contributions from accelerator experiments ● Inelastic cross section (by TOTEM) large → rapid development small → deep penetrating ● Inelasticity k = 1 – p lead / p mean First neutrons interaction large → rapid development small → deep penetrating ● Forward energy spectrum photons, π 0 softer → rapid development harder → deep penetrating ● Nuclear effects p-Pb collisions ● Extrapolation to high energies many precise measurements data at lower energies are points crucial 4

相互作用モデルの加速器実験による検証 Pseudo-rapidity • 空気シャワー発達に関連するのは、エネルギー流量の大きい ( 超 ) 前方領域 • 前方での粒子生成を測定し、相互作用モデルの予測と比較する 5

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The Large Hadron Collider forward ( LHCf ) experiment 66666 66666 !"#!$ 342. ! " 345 %&"'(!)"%*&+(',%*& "!& "!& -./012/32+412+53672.809 !"#$ !"#2. 34$ %&'()*+,&-*"./0)&"1#*,*" %&'()*+,&-*"./0)&"1#*,*" • Sampling & Imaging E.M. calorimeters 2 calorimeter towers Absorber: Tungsten 44X 0 , 1.6 λ int Energy measurement: 16 plastic scintillator tiles Imaging: 4 tracking layers Performance • Energy resolution ( >100GeV ) • 4 X-Y SciFi imaging layers • 4 X-Y Silicon strip 5% for γ , 40% for neutron + MAPMTs • Position resolution (E.M shower) imaging layers • 20mm x 20mm + • 25mm x 25mm + < 200 µm (#Arm1) 40mm x 40mm 32mm x 32mm ~ 40 µm (#Arm2) 7

The LHCf collaboration The LHCf Collaboration *,** Y.Itow, * Y.Makino, * K.Masuda, * Y.Matsubara, * E.Matsubayashi, *** H.Menjo, * Y.Muraki, *,** T.Sako, * K.Sato, * M.Shinoda, * M.Ueno, * Q.D.Zhou * Institute for Space-Earth Environmental Research, Nagoya University, Japan ** Kobayashi-Maskawa Institute, Nagoya University, Japan *** Graduate School of Science, Nagoya University, Japan K.Yoshida Shibaura Institute of Technology, Japan T.Iwata, K.Kasahara, T.Suzuki, S.Torii Waseda University, Japan Y.Shimizu, T.Tamura Kanagawa University, Japan N.Sakurai Tokushima University, Japan M.Haguenauer Ecole Polytechnique, France W.C.Turner LBNL, Berkeley, USA O.Adriani, E.Berti, L.Bonechi, M.Bongi, G.Castellini, R.D’Alessandro, P.Papini, S.Ricciarini, A.Tiberio INFN, Univ. di Firenze, Italy A.Tricomi INFN, Univ. di Catania, Italy 2 8

The LHCf collaboration The LHCf Collaboration student *,** Y.Itow, * Y.Makino, * K.Masuda, * Y.Matsubara, * E.Matsubayashi, *** H.Menjo, * Y.Muraki, *,** T.Sako, * K.Sato, * M.Shinoda, * M.Ueno, * Q.D.Zhou * Institute for Space-Earth Environmental Research, Nagoya University, Japan ** Kobayashi-Maskawa Institute, Nagoya University, Japan *** Graduate School of Science, Nagoya University, Japan K.Yoshida Shibaura Institute of Technology, Japan T.Iwata, K.Kasahara, T.Suzuki, S.Torii Waseda University, Japan Y.Shimizu, T.Tamura Kanagawa University, Japan N.Sakurai Tokushima University, Japan M.Haguenauer Ecole Polytechnique, France W.C.Turner LBNL, Berkeley, USA O.Adriani, E.Berti, L.Bonechi, M.Bongi, G.Castellini, R.D’Alessandro, P.Papini, S.Ricciarini, A.Tiberio INFN, Univ. di Firenze, Italy A.Tricomi INFN, Univ. di Catania, Italy 2 9

Photon energy spectra @ √ s = 7TeV • No model can reproduce LHCf spectra • but data points are among model predictions 10

Neutron spectra @ √ s = 7 TeV η η η > 10.76 8.99 < < 9.22 8.81 < < 8.99 × -3 × -3 × -3 10 10 10 0.6 2.4 2.4 /dE [mb/GeV] /dE [mb/GeV] /dE [mb/GeV] DPMJET 3.04 DPMJET 3.04 DPMJET 3.04 LHCf s = 7 TeV LHCf s = 7 TeV LHCf s = 7 TeV 2.2 2.2 EPOS 1.99 PYTHIA 8.145 EPOS 1.99 PYTHIA 8.145 EPOS 1.99 PYTHIA 8.145 0.5 2 2 QGSJET II-03 SYBILL 2.1 QGSJET II-03 SYBILL 2.1 QGSJET II-03 SYBILL 2.1 1.8 1.8 n n n σ σ σ 0.4 1.6 1.6 d d d 1.4 1.4 0.3 1.2 1.2 1 1 0.2 0.8 0.8 0.6 0.6 0.1 0.4 0.4 0.2 0.2 0 0 0 0 500 1000 1500 2000 2500 3000 3500 0 500 1000 1500 2000 2500 3000 3500 0 500 1000 1500 2000 2500 3000 3500 Energy [GeV] Energy [GeV] Energy [GeV] • Neutron production may be relevant to muon production • Could be a key for muon problem • EPOS 1.99, QGSJETII-03, SIBYLL 2.1 were not able to reproduce measured spectra 11

Publications Proton equivalent π 0 Gamma Neutron energy in lab (eV) Detector NIM A, 671, 129 JINST 9 P030016 performance - - (2012) (2014) (old) p+p Phys. Lett. B 715 4.3x10 14 - √ s = 900GeV 298 (2012) Former p+p Phys. Lett. B 703, Phys. Lett. B 750 Phys. Rev. D 86, 2.6x10 16 detector √ s = 7TeV 128 (2011) (2015) 360366 092001 (2012) + p+p Phys. Rev. C 89, 4.1x10 15 √ s = 2.76 TeV 065029 (2014) + Phys. Rev. D 94 p+Pb 1.4x10 16 032007 (2016) √ s = 5.02 TeV Detector to be submitted performance - - Upgraded (JINST) (new) detector Analysis p+p 10 17 completed, Next target √ s = 13 TeV paper writing 12

レータからなるシャワー位置検出器 New rad-hard LHCf detectors for √ s=13 TeV LHCf 検出器の設置場所は LHC の中でも放射線環境が過酷なところ。 特に 13 TeV 測定では 30 Gy/nb -1 に達し、プラシン等では正確な測定が無理 カロリメータと位置検出器 SciFi で使用していた、プラシンを Gd 2 SiO 5 (GSO) に変更 Sampling layer with GSO GSO-bar hodoscope X-Y 井桁状に並べた 1mm pitch の GSO シンチ 13

Beam tests @ SPS, CERN • 2012/2014/2015 の 3 回実施 • 100-250 GeV electron/muon, 200-350 GeV proton を使用 • √ s=13 TeV で測定するのは 200 < E < 6500 GeV • 検出器の calibration & performance check 14

Beam tests @ SPS, CERN m] µ Data X Resolution [ Total energy deposit [GeV] 8 250 Data Y Shower peak 
 MC X 7 MC Y position resolution 200 6 <100µm 5 Detector simulation reproduced 150 4 measured data very well 100 3 Non-linearity 2 <0.5% 50 1 0 0 0 50 100 150 200 250 15 50 100 150 200 250 Electron beam energy [GeV] Electron beam energy [GeV] Sampled energy [MeV]

Installation (Nov. 2014) 16

ビームパイプ ATLAS ( 含衝突点 ) がある方向 LHCf 検出器 中性子のダンパー ( ここでビームパイプが２本に別れる ) 17

“LHCf dedicated run” in p-p √ s=13TeV, 2015 LHCf dedicated run • Very-low luminosity special runs for LHCf • 3 days for all physics program!! • No mistake is allowed… LHCf control room (“barrack”) g n i z 18 18 g 
 n i o

13 TeV run, event display, π 0 candidate 19

13 TeV run, event display, π 0 candidate 20

plots from 13TeV data… Beam center calculation Photon/hadron separation Events Data 800 Photon template 700 Neutron template 600 500 400 300 200 100 0 0 5 10 15 20 25 30 35 40 45 50 Depth of 90% total-energy-deposit [X ] 0 21

Energy scale monitoring during the operation : pi0 mass 22

LHCf photon spectra @ √ s=13 TeV !"#$%&%'(")*+,-.-'*#'#"/)*0+#1."(*%'*++*23*4#5 • DPMJET3, SIBYLL2.1 など pre-LHC のモデルは測定値との乖離が激しい • post-LHC のモデル (QGSJETII-04, EPOS-LHC) が測定値を良く再現 23

pp √ s=13 TeV, Photon energy fm ow measurement pp 散乱の Photon へのエネルギー流量の η 依存性 [GeV] >200 GeV photon only 350 Data QGSJETII-04 η dE/d 80 300 EPOS-LHC [mm] 25 SIBYLL 2.3 70 250 #1."(*%'*++*23*4#5 60 20 50 200 40 15 30 150 20 10 100 "#$%&%'(")*+,-.-'*#'#"/)*0+ 10 0 5 50 − 10 − 20 0 − − − 30 20 10 0 10 20 30 0 5 6 7 8 9 10 11 12 13 [mm] η 24