reactor & accelerator
DESCRIPTION
Reactor & Accelerator . Thanks to Bob McKeown for many of the slides. Outline. Reactor Neutrinos The neutrinos Past experiments What we know and what we want to learn Accelerator Neutrinos The neutrinos Past experiments What we know and what we want to learn. n e Disappearance. - PowerPoint PPT PresentationTRANSCRIPT
Reactor & Accelerator
Thanks to Bob McKeown for many of the slides
June 2005 Steve Elliott, NPSS 2005 2
Outline
• Reactor NeutrinosThe neutrinosPast experimentsWhat we know and what we want to learn
• Accelerator NeutrinosThe neutrinosPast experimentsWhat we know and what we want to learn
June 2005 Steve Elliott, NPSS 2005 3
Distance (m)
P(ee)
€
Pee ≈1− cos4 θ13 1− sin2θ12 sin2 Δm122L
4Eν
⎛
⎝ ⎜
⎞
⎠ ⎟
⎡
⎣ ⎢
⎤
⎦ ⎥
Dominant 12 Oscillation
€
Pee ≈1− sin2 2θ13 sin2 Δm312L
4Eν+ Δm21
2L4Eν
⎛
⎝ ⎜
⎞
⎠ ⎟cos4 θ13 sin2 2θ12
Subdominant 13 Oscillation
e Disappearance
June 2005 Steve Elliott, NPSS 2005 4
13
90, 95, 99% CL
hep-
ph/0
3091
30
m232 from SK
atmospheric
Chooz
Solar
122
134
122
134
NCCC sinsinsincos/ ≈+≈ΦΦ
June 2005 Steve Elliott, NPSS 2005 5
Neutrino Oscillation Studies with Nuclear Reactors
• e from n-rich fission products
• detection via inverse beta decay (e+pe++n)
• Measure flux and energy spectrum
• Improve detectors, reduce background
• Variety of distances L= 10m-250km
June 2005 Steve Elliott, NPSS 2005 6
Detection Signal
Coincidence signal: detect• Prompt: e+ annihilation EEprompt+En+0.8 MeV• Delayed: n capture 180 s capture time
p+e
511keV
511keV 2.2 MeV
d
n
June 2005 Steve Elliott, NPSS 2005 7
June 2005 Steve Elliott, NPSS 2005 8
KamLAND usesthe entire Japanese
nuclear powerindustry as a
long baseline source
Kashiwazaki
Takahama
Ohi
June 2005 Steve Elliott, NPSS 2005 9
June 2005 Steve Elliott, NPSS 2005 10
Solar : m2 = 5.5x10-5 eV2
sin2 2 = 0.833
G.Fogli et al., PR D66, 010001-406,(2002)
Ratio of Measured and Expected e Flux from Reactor Neutrino Experiments
June 2005 Steve Elliott, NPSS 2005 11
Measurement of Energy Spectrum
June 2005 Steve Elliott, NPSS 2005 12
KamLAND best fit : m2 = 7.9 x 10-5 eV2
tan2 = 0.45
KamLAND fixes massSolar fixes angle
June 2005 Steve Elliott, NPSS 2005 13
New Reactor Proposals
Braidwood, Il
Daya Bay, China
Chooz, France• ~1.5 km baseline• Deeper/bigger• Near/Far
June 2005 Steve Elliott, NPSS 2005 14
Detector Design Studies
horizontal cylinder
horizontal cylinder
spherical
June 2005 Steve Elliott, NPSS 2005 15
Oscillation Formulae for Long-Baseline Neutrinos
For anti-neutrinos, the Jcp terms change sign.
June 2005 Steve Elliott, NPSS 2005 16
Long Baseline Physics Goals
• Definitive observation of oscillatory behavior in disappearance mode and precise determination of m2
23 and 23.• Detection of oscillation e in appearance
mode and measurement of 13.• Observe matter effects, hence sign of m2
23.• Measure cp
June 2005 Steve Elliott, NPSS 2005 17
CP violation and matter effects
hep-
ph/0
3062
21
June 2005 Steve Elliott, NPSS 2005 18
T2K
Phase I0.75 MW +SKPhase II4 MW + HyperK
June 2005 Steve Elliott, NPSS 2005 19
HyperK
June 2005 Steve Elliott, NPSS 2005 20
NOAUse the NUMI beam line from FermiLab.Far detector uses alternate vertical planes of active scintillator with passive wood absorber.
June 2005 Steve Elliott, NPSS 2005 21
Off-Axis Beam• For pions decaying in
flight, most neutrinos are forward directed
• Neutrino energy is proportional to E
• Neutrino energy flattens with angle, however. Allowing one to “choose” an energy by choosing the angle.
June 2005 Steve Elliott, NPSS 2005 22
Far Detector810 km from target10-14 km off axis
June 2005 Steve Elliott, NPSS 2005 23
LONG baseline 2500-3000 km
June 2005 Steve Elliott, NPSS 2005 24
The LSND Puzzle and MiniBOONE
30 meters
e etectorNeutrios e , , a
Protobea
Pios
Coer bea sto
Muos a electros
Watertaret
June 2005 Steve Elliott, NPSS 2005 25
The Evidence for Neutrino Oscillations
June 2005 Steve Elliott, NPSS 2005 26
Requires a 3rd m2
June 2005 Steve Elliott, NPSS 2005 27
June 2005 Steve Elliott, NPSS 2005 28
June 2005 Steve Elliott, NPSS 2005 29
Measurement of Oscillation Parameters
June 2005 Steve Elliott, NPSS 2005 30
Typical Muon-Neutrino Event
June 2005 Steve Elliott, NPSS 2005 31
Typical Michel Electron Event
June 2005 Steve Elliott, NPSS 2005 32
Resources
• Bob Mckeown APS April 2005 (Tampa)• APS neutrino study on reactors and
long baseline experiments.• BNL, T2K and NOA Letters of Intent• Bill Louis Talks