Document

Sept 20, 2006
奈良
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, KEKB, 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
Contents
1. Cross Section for Neutrino Reactions
2. Fermi National Laboratory Booster Neutrino Beam
3. SciBooNE Experiment
4. Summary
1. Neutrino Cross Section
Charged Current
Neutral Current




W
Z
p
p
   p    p
p
n
   n    p
Neutrino-induced reaction (CC)
  n    p

( )

Carbon Target
12
7
Anti-neutrino induced reaction (CC)
  p    n

(  )
12
5
N
B
12
6
C
Mirror Nuclei
Nuclear Targets:
Elastic
Quasi-elastic
Resonance Production (  )
Coherent  Production, Non-resonant  Production
Charged Current
QE
Data from earlier
experiments (1970~1980)
Low statistics
Systematic uncertainties
Nuclear effects
(/p/n absorption/scattering,
low Q2 region)
Not well-modelled
DIS
resonance
Oscillation maximum
in T2K
More data around 1GeV are essential
to advance Neutrino Physics
2. Booster Neutrino Beam (BNB) at FNAL
Protons from Booster: 8 GeV
cf. NuMI
Being operated for MiniBooNE since 2002
Meson production cross section by HARP at CERN
エネルギー：
J-PARK T2K とほぼ同じ
3. SciBooNE実験
FNAL E-954
BNB + SciBar
SciBooNE 実験の目的
• 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。
ニュートリノビームと標的・検出器の配置
MiniBooNE beamline
SciBar
Decay region
MiniBooNE
Detector
50 m
440 m
100 m
•
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

SciBar
3.5m
3m
MRD 4m
3m
1.7m
EC
~1.5m
Fermi National Laboratory
MiniBooNE
SciBooNE実験ホール
このあたり
実験ホール
~8m
SciBar
スケジュール：
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
1 年間の Run (2x1020 proton on target)
ニュートリノビーム Run
0.5x1020 POT:
(cf. K2K-SciBar: 0.21020 POT)
CC-non-QE の断面積測定(ex. +n  p++)
反ニュートリノビーム Run
1.5x1020 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 1pi0
746
---------------------------------------Total
77,960
----------------------------------------
Summary
SciBooNE is an experiment of neutrino and antineutrino
cross section measurements around 1 GeV
The aims are to study neutrino cross section for T2K and
also to open up ‘Nuclear Physics with Neutrino Beam’
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
Cooperation with theoretical physicists is highly important
2. Booster Neutrino Beam (BNB) at FNAL
cf. NuMI
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
Meson Production Cross Sections by HARP at CERN
Being Operated for MiniBooNE since 2002
実験ホールにおける Detector
EC MRD
SciBar
Area of circle is proportional to ADC.
Hits along the proton track are larger
CCQE candidate

p

CC-non-QE candidate
νμ+ p 
μ+p+π
3

νμ+ n  μ + p
2
1
NC elastic scattering cand.
NC 0 candidate
p
ν μ+ N
 νμ+ N + π0
Vertex!
e
e candidate
g

0
g
p
Large energy deposit
in Electron Catcher
e
νe+ n  e + p e

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