フェルミ国立研における SciBooNE による ニュートリノ － 核子・原子核反応断面積の測定 東工大理, 京大理 A, KEK B, 東大宇宙線研 C 柴田利明, 宮地義之, 武居秀行, 中家剛 A, 横山将志 A, 田中秀和 A, 平出克樹 A, 栗本佳典 A, 中島康博 A, 石井孝 B, 田中真伸 B, 早戸良成 C, 他 SciBooNE Collaboration Sept 20, 2006 奈良

Contents 1. Cross Section for Neutrino Reactions 2. Fermi National Laboratory Booster Neutrino Beam 3. SciBooNE Experiment 4. Summary

Neutral Current Z W Charged Current 1. Neutrino Cross Section

Neutrino-induced reaction (CC) Anti-neutrino induced reaction (CC) Nuclear Targets: Elastic Quasi-elastic Resonance Production ( ) Coherent Production, Non-resonant Production Carbon Target Mirror Nuclei

Oscillation maximum in T2K DIS Data from earlier experiments ( 1970~1980 ) Low statistics Systematic uncertainties Nuclear effects (  p/n absorption/scattering, low Q 2 region) Not well-modelled QE resonance More data around 1GeV are essential to advance Neutrino Physics Charged Current

Protons from Booster: 8 GeV 2. Booster Neutrino Beam (BNB) at FNAL cf. NuMI Being operated for MiniBooNE since 2002 エネルギー： J-PARK T2K とほぼ同じ Meson production cross section by HARP at CERN

3.SciBooNE 実験 FNAL E-954 BNB + SciBar

次期長基線ニュートリノ振動実験 J-PARK T2K に向けて、 1GeV 近辺 のニュートリノ反応を良く理解し ておくことが重要。 ニュートリノビームをプローブと した 原子核物理の創生。 SciBooNE 実験の目的

実験標的＋検出器 （アクティブ ターゲッ ト）： ニュートリノビーム生成標的の下流 100m Decay region 50 m MiniBooNE Detector SciBar MiniBooNE beamline 100 m 440 m 3.5m 4m ~1.5m MRD SciBar 1.7m 3m EC ニュートリノビームと標的・検出器の配置

MiniBooNE SciBooNE 実験ホール Fermi National Laboratory

~8m SciBar 実験ホール このあたり

2005 年 12 月に 採択： E954 “ SciBooNE ” 2006 年 5-8 月 SciBar の搬送 (KEK  FNAL) 2006 年 10,11 月 測定器組み立て 2006 年 12 月 実験スタート スケジュール： 1 年間の Run (2x10 20 proton on target) ニュートリノビーム Run 0.5x10 20 POT: (cf. K2K-SciBar: 0.2  POT) CC-non-QE の断面積測定 (ex.  +n  p+  +  ) 反ニュートリノビーム Run 1.5x10 20 POT CCQE, CC-non-QE の断面積測定

Expected Number of Events Neutrino-induced reactions Reaction Number of Events CC QE 31,720 CC resonant 1pi+ 14,108 NC elastic 13,751 CC multi-pi 5,279 NC resonant 1pi0 3,723 CC resonant 1pi0 3,106 NC resonant 1pi+- 2,372 NC multi-pi 1,723 CC coherent 1pi+ 1,432 NC coherent 1pi Total 77,

Summary SciBooNE is an experiment of neutrino and antineutrino cross section measurements around 1 GeV It uses Booster Neutrino Beam at FNAL, and a detector (SciBar, EC, MRD) It measures Cross section for Nuclear Elastic scattering, Quasi-elastic, Resonance Production ( ), Coherent and non-Resonant Productions in charged and neutral current interactions The aims are to study neutrino cross section for T2K and also to open up ‘ Nuclear Physics with Neutrino Beam ’ Cooperation with theoretical physicists is highly important

Meson Production Cross Sections by HARP at CERN Protons from Booster: 8 GeV, maximum rate 5Hz, a batch is 1.6x10 -6 s wide and consists of 84 bunches, one bunch is 4ns wide, 19 ns peak-to-peak separation to next bunch  background suppression 2. Booster Neutrino Beam (BNB) at FNAL cf. NuMI Being Operated for MiniBooNE since 2002

SciBar MRD EC 実験ホールにおける Detector

 p CCQE candidate CC-non-QE candidate Area of circle is proportional to ADC. Hits along the proton track are larger ν μ + n  μ + p ν μ + p  μ + p + π μ + p + π

Vertex! 00 e e   NC elastic scattering cand. p ν μ + N  ν μ + N + π 0  ν μ + N + π 0 Large energy deposit in Electron Catcher e p e candidate ν e + n  e + p NC  0 candidate