Superbeams Deborah Harris Fermilab July 26, 2004 NuFact’04 Osaka University.
What can Superbeams and Neutrino Factories Add to n Scattering Measurements?
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Transcript of What can Superbeams and Neutrino Factories Add to n Scattering Measurements?
What can Superbeams and What can Superbeams and Neutrino Factories Add to Neutrino Factories Add to Scattering Measurements?Scattering Measurements?
What What Scattering Scattering Measurements will we want Measurements will we want in era of Superbeams and in era of Superbeams and
Neutrino Factories?Neutrino Factories?
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Physics and BeamsPhysics and Beams• Neutral Current Neutral Current
Measurements vs EMeasurements vs E
• Anti-neutrino cross sections Anti-neutrino cross sections & interactions& interactions
• HH22, D, D22 Measurements Measurements
• Polarized Target Polarized Target Measurements (spin Measurements (spin structure functions)structure functions)
• Narrow Band Narrow Band Beams Beams– How narrow is narrow?How narrow is narrow?– Are there tricks to get Are there tricks to get
more narrow beams?more narrow beams?
• Broad Band Broad Band Beams Beams– Largest rate Largest rate – No NC vs ENo NC vs E available available
• Beta-beamsBeta-beams– Broad band, Low EnergyBroad band, Low Energy
• Neutrino FactoriesNeutrino Factories– Broad BandBroad Band– Neutrino and antineutrino Neutrino and antineutrino
at the same time, if you at the same time, if you can reconstruct can reconstruct and and ee CC CC
– NO NC vs ENO NC vs E or even vs or even vs neutrino helicity!neutrino helicity!
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What Neutrino Beams may be What Neutrino Beams may be Available?Available?
• Energies from Energies from 200MeV to 15GeV200MeV to 15GeV
• Broad and NarrowBroad and Narrow
• But near and far But near and far beams aren’t beams aren’t identical…narrow identical…narrow beams not as beams not as narrow at near sitenarrow at near site
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How Narrow is “Narrow How Narrow is “Narrow Band”?Band”?• Near Detector sees line source, Far detector sees Near Detector sees line source, Far detector sees
point sourcepoint source
• NB fluxes on previous slide not the same!NB fluxes on previous slide not the same!• One way to fix this: go far enough away (T2K 2km One way to fix this: go far enough away (T2K 2km
detector)detector)• Another way to improve this: Run with 0 horn Another way to improve this: Run with 0 horn
current and subtract off “high energy tail” current and subtract off “high energy tail”
From NOA:FD: 20% FWHMND: 40% FWHM and higher “high energy tail”
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Tale of One BeamlineTale of One Beamline• People are thinking of many far detectors at People are thinking of many far detectors at
many on and off axis locations for oscillationsmany on and off axis locations for oscillations
• We can also think of how many different near site We can also think of how many different near site locations might be available for different neutrino locations might be available for different neutrino scattering measurements scattering measurements
• Following slides come from K.McFarland’s Following slides come from K.McFarland’s presentation at the 11/2002 FNAL-PAC meeting presentation at the 11/2002 FNAL-PAC meeting
Shaft
Near HallAbsorber
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Off-Axis BeamsOff-Axis Beams• Illustration at Illustration at
NUMI near NUMI near detector sitedetector site– Peak energy shifts Peak energy shifts
lowerlower– Width decreasesWidth decreases– High energy tail High energy tail
suppressedsuppressed– Rate significantly Rate significantly
decreaseddecreased
On Axis5m
10m
20m
On Axis
5m
10m20m
NUMI Near On and Off-Axis Beams(beam sim. courtesy M. Messier)
NUMI LEConfiguration
NUMI ME
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Site 3: 5-15 meters Off-AxisSite 3: 5-15 meters Off-Axis
• Located upstream of Located upstream of absorberabsorber– Wide, unfinished tunnel. Wide, unfinished tunnel.
Sloped floor (9% grade).Sloped floor (9% grade).
• Not an attractive siteNot an attractive site– Far from shaft and utility Far from shaft and utility
sourcesource– Interferes with absorber Interferes with absorber
utitilies? Radiation? utitilies? Radiation?
– <E<E>~1.5-3+ GeV>~1.5-3+ GeV
Shaft
Near Hall
Absorber
15m
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Site 1: Interaction RatesSite 1: Interaction Rates
Shaft
Near Hall
Absorber
LE+, 10m
ME+, 10m
ME+, 5m
LE+, 5m
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Site 2: Interaction RatesSite 2: Interaction Rates
Shaft
Near Hall
Absorber
LE+, 15m
ME+, 15m
1111
Site 3: Interaction RatesSite 3: Interaction Rates
Shaft
Near Hall
Absorber
LE+, 15m
LE+, 13m
ME+, 13m
LE+, 9m
ME+, 9m
ME+, 11m
LE+, 11m
ME+, 15m
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DiscussionDiscussion
• Admission of prorities—new Admission of prorities—new beamlines won’t be built for neutrino beamlines won’t be built for neutrino scattering physics alone…scattering physics alone…
• How do we make sure to get the How do we make sure to get the most out of whatever beamline does most out of whatever beamline does get built?get built?