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Studying Nuclear Effects and Structure Functions at the NuMI Facility. Jorge G. Morfín Fermilab NuFact’02 London, July 2002. What are these Nuclear Effects?. F 2 / nucleon within a nucleus changes as a function of A. Nuclear effects measured (with high statistics) in -A not in .
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Studying Nuclear Effects and Structure Functions at the NuMI Facility Jorge G. Morfín Fermilab NuFact’02 London, July 2002
What are these Nuclear Effects? • F2 / nucleon within a nucleus changes as a function of A. • Nuclear effects measured (with high statistics) in -A not in . • From low-to-high xBj go through: shadowing, anti-shadowing, “EMC” effect, Fermi motion. Jorge G. Morfín - NuFact02 - London, July 2002
Are Nuclear Effects the SAME for n and e/m-A Scattering • Shadowing with nNOT the same as with charged leptons. • Axial vector component of current • Shadowing off valance quarks different than off sea quarks???? • Shadowing separate phenomena from nucleus, has to be put in “by hand”. • All such IVB effects are contained in nuclear parton distribution functions (Kumano, Eskola et al.) for parton level interactions. • EMC effect can be accounted for in nuclear spectral functions. Jorge G. Morfín - NuFact02 - London, July 2002
Any Indication of a Difference in Nuclear Effects of Valence and Sea Quarks? • Nuclear effects similar in Drell-Yan and DIS for x < 0.1. • Then no “anti-shadowing” in D-Ya while “anti-shadowing” seen in DIS (5-8% effect in NMC). • Indication of difference in nuclear effects between valence & sea quarks? a hep-ex/9906010 Jorge G. Morfín - NuFact02 - London, July 2002
Nuclear Parton Distribution Functions • This quantified by: • K.J. Eskolab et al within LO DGLAP using initial nuclear distributions from CTEQ4L and GRV-LO and assume scale evolution of nuclear parton densities is perturbative. • S. Kumano et alc hep-ph/0103208 plus a talk at this workshop • Neutrinoshave the ability to directly resolve flavor of the nucleon’s constituents: interacts with d, s, u, and c while interacts with u, c, d and s. Jorge G. Morfín - NuFact02 - London, July 2002 b hep-ph/9807297 c hep-ph/0103208
A Specific Look at Scattering Nuclear Effects • S.A.Kulagin has calculated shadowing for F2 • and xF3 in -A interactions based on a • non-perturbative parton model. • Shadowing in the low Q2 (A/VMD dominance) • region is much stronger than at higher Q2. Q2 = 5 GeV2 Jorge G. Morfín - NuFact02 - London, July 2002
Scattering Nuclear Effects compared to e/m-A Scattering Jorge G. Morfín - NuFact02 - London, July 2002 hep-ph/9812532
Goals in Study of Nuclear Effectswith scattering • Overall Goal: Measure nuclear effects across full xBj range in scattering off a variety of targets. • Goal: Measure nuclear effects separately for F2 and xF3. What are the nuclear effects for valence quarks alone ? Use as input to global nuclear PDF’s • Long-term Goal: High statistics scattering experiment on H2 and D2 as well as heavy nuclei to extract all six structure functions on nucleons as well as within nuclei. Jorge G. Morfín - NuFact02 - London, July 2002
Fermilab On-site Beam and Near Detector Hall • Target-Horn Chase: 2 parabolic horns. 50 m • Decay Region: 1m radius decay pipe. 675 m • Hadron Absorber: Steel with Al core 5 m • Muon range-out: dolomite (rock). 240 m • Near Detector Hall 45 m Jorge G. Morfín - NuFact02 - London, July 2002
Neutrino Event Energy Distributions and Statistics • Reasonably expect 2.5 x 1020 pot per year of NuMI running. • le-configuration: Events- Epeak = 3.0 GeV, <En> = 10.2 GeV, rate = 200 K events/ton - year. • me-configuration: Events- Epeak = 7.0 GeV, <En> = 8.5 GeV, rate = 675 K events/ton - year pme rate = 540 K events/ton - year. • he-configuration: Events- Epeak = 12.0 GeV, <En> = 13.5 GeV, rate = 1575 K events/ton - year phe rate = 1210 K events/ton - year. With E-907 at Fermilab to measure particle spectra from the NuMI target, expect to know neutrino flux to ±5%. Jorge G. Morfín - NuFact02 - London, July 2002
NuMI Near Hall: Dimensions & Geometry Length: 45m - Height: 9.6m - Width: 9.5m Length Available for New Detector:26 m Incoming angle: n beam: 58 mr Jorge G. Morfín - NuFact02 - London, July 2002
NuMI Beam Interacts Off-Module-Center Wonderful - inviting - spot for a new detector which could use MINOS near detector as a muon ID/spectrometer! Jorge G. Morfín - NuFact02 - London, July 2002
Initial Step... Scintillator Strips Planes of C, Fe, Pb MINOS Near Jorge G. Morfín - NuFact02 - London, July 2002
Detector: Conceptual Design • 2m x 2 cm x 2cm scintillator (CH) strips with fiber readout. • Fiducial volume: r = .8m L = 1.5: 3 tons of scintillator • Downstream half: pure scintillator • Upstream half: scintillator plus 2 cm thick planes of C, Fe and W. • 11 planes C = 1.0 ton (+Scintillator) • 3 planes Fe = .95 ton (+MINOS) • 2 planes Pb = .90 ton • Readout: combination of VLPC and multi-anode PMT. • Use MINOS near detector as muon identifier / spectrometer. Jorge G. Morfín - NuFact02 - London, July 2002
MINOS Parasitic Running: Event Energy Distribution • MINOS oscillation experiment uses mainly le beam with shorter pme and phe runs for control and minimization of systematics. • An example of a running cycle would be: • 12 months le beam • 3 months pme beam • 1 month phe beam • Assuming 2 such cycles (3 year run) with 2.5x1020 protons/year: 860 K events/ton. <En> = 10.5 GeV • DIS (W > 2 GeV, Q2 > 1.0 GeV2): 0.36 M events / ton. • Quasi elastic: 0.14 M events / ton. • Resonance + “Transition”: 0.36 M events / ton Jorge G. Morfín - NuFact02 - London, July 2002
MINOS Parasitic Running: x and Q2 Events / ton Jorge G. Morfín - NuFact02 - London, July 2002
Prime User: he Event Energy Distribution • Run he beam configuration only! <En> = 13.5 GeV • For example, 1 year neutrino plus 2 years anti-neutrino would yield: 1.6 M n - events/ton0.9 M n - events/ton • DIS (W > 2 GeV, Q2 > 1.0 GeV2): 0.80 M n events / ton 0.35 M n events / ton • Shadowing region (x < 0.1): 0.3 M events/ton Jorge G. Morfín - NuFact02 - London, July 2002
he-beam: x and Q2 Jorge G. Morfín - NuFact02 - London, July 2002
Add a Liquid H2/D2Target Additional Tracking Scintillator Strips H_2/D_2 MINOS Near Additional Tracking Planes of C, Fe, Pb Fiducial volume: r = 80 cm. and l = 150 cm. 350 K CC events LH2 ; 800 K CC events in LD2 per year he-n running. Jorge G. Morfín - NuFact02 - London, July 2002
Detector: Event Rates Event rates (2.5 x 1020 protons per year) Parasitic Running Prime User Prime User (3 years) (1 year, he-n) (2 year, he -n) CH 2.60 M 4.80 M 2.70 M C 0.85 M 1.60 M 0.90 M Fe 0.80 M 1.55 M 0.85 M Pb 0.75 M 1.45 M 0.80 M LH2 0.35 M 0.20 M LD2 0.80 M 0.45 M Jorge G. Morfín - NuFact02 - London, July 2002
Examples: Expected Statistical Errors-MINOS Parasitic(n running only) Ratio Fe/C: Statistical Errors xBjMINOS2-cycle .01 - .02 1.3 % .02 - .03 1.0 .03 - .04 0.9 .04 - .05 0.8 .05 - .06 0.8 .06 - .07 0.7 Jorge G. Morfín - NuFact02 - London, July 2002
Examples: Expected Statistical Errors - he Running Ratios (he, 1 year n, DIS): Statistical Errors xBjFe/ LD2Fe/C .01 - .02 11% 9 % .02 - .03 6 5 .03 - .04 4 3 .04 - .05 3 2 .05 - .06 2 1.7 .06 - .07 1.7 1.4 Taking ratios: beam systematics cancel. Assume relative target systematics are the same as Tevatron Muon Expt. O (1 %). High xBj (he, 1 year, DIS): Statistical Errors xBjCHLH2LD2 .60 - .65 0.6 % 2 % 1.4 % .65 - .70 0.7 3 1.7 .70 - .75 1.0 4 2 .75 - .80 1.3 5 3 .80 - .85 2 7 5 .85 - .90 3 11 7 .90 - .95 5 17 11 .95 - 1.0 7 25 16 Jorge G. Morfín - NuFact02 - London, July 2002
Fractional Statistical Errors in Measurements of Fi Ratios • Assuming he beam 1 year n and 2 year n • One ton fiducial mass of C, Fe and Pb • 0.5 ton fiducial mass of D2 Jorge G. Morfín - NuFact02 - London, July 2002
Six Structure Functions for Maximal Information on PDF’s + y2 FL X = 0.1 - 0.125 Q2 = 2 - 4 GeV2 Jorge G. Morfín - NuFact02 - London, July 2002
What Can We Learn With All Six Structure Functions? Leading order expressions: • Does s = s and c = c over all x? • If so..... Jorge G. Morfín - NuFact02 - London, July 2002
Neutrino Factory: Expected Errors on Measured F’s • D2 Target: r = 50 cm & l = 60 cm. • One year exposure. • Errors on F1 better than 10% • Assume the Callan-Gross relationship eliminating F1. • Errors now O (1%) or better over most of the x-range. Jorge G. Morfín - NuFact02 - London, July 2002
Summary • Some nuclear effects are predicted to be different for n as compared to e/m scattering. • Furthermore, Kulagin predicts nuclear effects different for valance as compared to sea quarks. • We need to measure these nuclear effects as well as F2 and xF3 off different A targets to extract the nuclear parton distribution functions. • NuMI Facility excellent for this purpose. • The NuMI beam is Intense: • yielding≈ 860 K events/ton during MINOS run* • yielding ≈ 1.6 M events/ton-year in the he_n -mode. • NuMI Near Hall: • space for new detector(s) with w(x) ≤ 6 m, h(y) ≤ 4 m,(sum) L ≈ 25 m. • NuMI Near Hall Detector studies underway: • “pure scintillator planes” + planes of A: 3 - 5 ton fiducial volume - cost O($3M) • liquid H2 / D2 (bubble chamber): large target technically feasible - safety requirements..? • Withthese detectors and a 1 year he_n and 2 year he_n exposure, we could measure the ratio (A/ D2) of F2 for x > .01 to better than 10% and ratio of xF3 for x > .02 to better than 30% (better than 18 % for x > .02). Jorge G. Morfín - NuFact02 - London, July 2002