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?

33

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!

44

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

55

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”

66

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

77

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

88

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

99

Site 1: Interaction RatesSite 1: Interaction Rates

Shaft

Near Hall

Absorber

LE+, 10m

ME+, 10m

ME+, 5m

LE+, 5m

1010

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

1212

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?