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Studying Nuclear Effects and Structure Functions at the NuMI Facility

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

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  1. Studying Nuclear Effects and Structure Functions at the NuMI Facility Jorge G. Morfín Fermilab NuFact’02 London, July 2002

  2. 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

  3. 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

  4. 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

  5. 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 • Neutrinoshave 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

  6. 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

  7.  Scattering Nuclear Effects compared to e/m-A Scattering Jorge G. Morfín - NuFact02 - London, July 2002 hep-ph/9812532

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. Initial Step... Scintillator Strips Planes of C, Fe, Pb MINOS Near Jorge G. Morfín - NuFact02 - London, July 2002

  14. 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

  15. 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

  16. MINOS Parasitic Running: x and Q2 Events / ton Jorge G. Morfín - NuFact02 - London, July 2002

  17. 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

  18. he-beam: x and Q2 Jorge G. Morfín - NuFact02 - London, July 2002

  19. 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

  20. 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

  21. 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

  22. 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

  23. 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

  24. 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

  25. 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

  26. 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

  27. 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

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