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

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Presentation on theme: "Studying Nuclear Effects and Structure Functions at the NuMI Facility Jorge G. Morfín Fermilab NuFact’02 London, July 2002."— Presentation transcript:

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

2 Jorge G. Morfín - NuFact02 - London, July 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   From low-to-high x Bj go through: shadowing, anti-shadowing, “EMC” effect, Fermi motion.

3 Jorge G. Morfín - NuFact02 - London, July Are Nuclear Effects the SAME for and e/  Scattering  Shadowing with NOT the same as with charged leptons. t Axial vector component of current t 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.

4 Jorge G. Morfín - NuFact02 - London, July 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-Y a while “anti-shadowing” seen in DIS (5-8% effect in NMC).  Indication of difference in nuclear effects between valence & sea quarks? a hep-ex/

5 Jorge G. Morfín - NuFact02 - London, July Nuclear Parton Distribution Functions  This quantified by : t K.J. Eskola b et al within LO DGLAP using initial nuclear distributions from CTEQ4L and GRV-LO and assume scale evolution of nuclear parton densities is perturbative. t S. Kumano et al c hep-ph/ 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. b hep-ph/ c hep-ph/

6 Jorge G. Morfín - NuFact02 - London, July A Specific Look at Scattering Nuclear Effects Q 2 = 5 GeV 2 S.A.Kulagin has calculated shadowing for F 2 and xF 3 in -A interactions based on a non-perturbative parton model. Shadowing in the low Q 2 (A/VMD dominance) region is much stronger than at higher Q 2.

7 Jorge G. Morfín - NuFact02 - London, July Scattering Nuclear Effects compared to e/  Scattering hep-ph/

8 Jorge G. Morfín - NuFact02 - London, July Goals in Study of Nuclear Effects with  scattering  Overall Goal: Measure nuclear effects across full x Bj range in  scattering off a variety of targets.  Goal: Measure nuclear effects separately for F 2 and xF 3. 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 H 2 and D 2 as well as heavy nuclei to extract all six structure functions on nucleons as well as within nuclei.

9 Jorge G. Morfín - NuFact02 - London, July 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

10 Jorge G. Morfín - NuFact02 - London, July Neutrino Event Energy Distributions and Statistics  Reasonably expect 2.5 x pot per year of NuMI running.  le-configuration: Events- E peak = 3.0 GeV, = 10.2 GeV, rate = 200 K events/ton - year.  me-configuration: Events- E peak = 7.0 GeV, = 8.5 GeV, rate = 675 K events/ton - year pme rate = 540 K events/ton - year.  he-configuration: Events- E peak = 12.0 GeV, = 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%.

11 Jorge G. Morfín - NuFact02 - London, July NuMI Near Hall: Dimensions & Geometry Length: 45m - Height: 9.6m - Width: 9.5m Length Available for New Detector: 26 m Incoming angle: beam: 58 mr

12 Jorge G. Morfín - NuFact02 - London, July NuMI Beam Interacts Off-Module-Center Wonderful - inviting - spot for a new detector which could use MINOS near detector as a muon ID/spectrometer!

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

14 Jorge G. Morfín - NuFact02 - London, July 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. t 11 planes C = 1.0 ton (+Scintillator) t 3 planes Fe =.95 ton (+MINOS) t 2 planes Pb =.90 ton  Readout: combination of VLPC and multi-anode PMT.  Use MINOS near detector as muon identifier / spectrometer.

15 Jorge G. Morfín - NuFact02 - London, July 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: t 12 months le beam t 3 months pme beam t 1 month phe beam  Assuming 2 such cycles (3 year run) with 2.5x10 20 protons/year: 860 K events/ton. = 10.5 GeV t DIS (W > 2 GeV, Q 2 > 1.0 GeV 2 ) : 0.36 M events / ton. t Quasi elastic: 0.14 M events / ton. t Resonance + “Transition”: 0.36 M events / ton

16 Jorge G. Morfín - NuFact02 - London, July MINOS Parasitic Running: x and Q 2 Events / ton

17 Jorge G. Morfín - NuFact02 - London, July Prime User: he Event Energy Distribution  Run he beam configuration only! = 13.5 GeV  For example, 1 year neutrino plus 2 years anti-neutrino would yield: 1.6 M - events/ton 0.9 M - events/ton  DIS (W > 2 GeV, Q 2 > 1.0 GeV 2 ): 0.80 M events / ton 0.35 M events / ton t Shadowing region (x < 0.1): 0.3 M events/ton

18 Jorge G. Morfín - NuFact02 - London, July he-beam: x and Q 2

19 Jorge G. Morfín - NuFact02 - London, July Add a Liquid H 2 /D 2 Target H_2/D_2 Scintillator Strips MINOS Near Additional Tracking Fiducial volume: r = 80 cm. and l = 150 cm. 350 K CC events LH 2 ; 800 K CC events in LD 2 per year he- running. Planes of C, Fe, Pb Additional Tracking

20 Jorge G. Morfín - NuFact02 - London, July Detector: Event Rates Event rates (2.5 x protons per year) Parasitic Running Prime User Prime User (3 years) (1 year, he- ) (2 year, he - ) CH2.60 M4.80 M 2.70 M C0.85 M1.60 M 0.90 M Fe0.80 M1.55 M 0.85 M Pb0.75 M1.45 M 0.80 M LH M 0.20 M LD M 0.45 M

21 Jorge G. Morfín - NuFact02 - London, July Examples: Expected Statistical Errors-MINOS Parasitic ( running only) Ratio Fe/C: Statistical Errors x B j MINOS 2-cycle %

22 Jorge G. Morfín - NuFact02 - London, July Examples: Expected Statistical Errors - he Running Ratios (he, 1 year, DIS): Statistical Errors x B j Fe/ LD 2 Fe/C %9 % High x Bj (he, 1 year, DIS): Statistical Errors x B j CHLH 2 LD % 2 % 1.4 % Taking ratios: beam systematics cancel. Assume relative target systematics are the same as Tevatron Muon Expt. O (1 %).

23 Jorge G. Morfín - NuFact02 - London, July Fractional Statistical Errors in Measurements of F i Ratios  Assuming he beam 1 year and 2 year  One ton fiducial mass of C, Fe and Pb  0.5 ton fiducial mass of D 2

24 Jorge G. Morfín - NuFact02 - London, July Six Structure Functions for Maximal Information on PDF’s X = Q 2 = GeV 2 + y 2 F L

25 Jorge G. Morfín - NuFact02 - London, July What Can We Learn With All Six Structure Functions?  Does s = s and c = c over all x?  If so..... Leading order expressions:

26 Jorge G. Morfín - NuFact02 - London, July Neutrino Factory: Expected Errors on Measured F’s  D 2 Target: r = 50 cm & l = 60 cm.  One year exposure.  Errors on F 1 better than 10%  Assume the Callan-Gross relationship eliminating F 1.  Errors now O (1%) or better over most of the x-range.

27 Jorge G. Morfín - NuFact02 - London, July Summary  Some nuclear effects are predicted to be different for as compared to e/  scattering.  Furthermore, Kulagin predicts nuclear effects different for valance as compared to sea quarks.  We need to measure these nuclear effects as well as F 2 and xF 3 off different A targets to extract the nuclear parton distribution functions.  NuMI Facility excellent for this purpose.  The NuMI beam is Intense: t yielding ≈ 860 K events/ton during MINOS run*  yielding ≈ 1.6 M events/ton-year in the he_ -mode.  NuMI Near Hall: t space for new detector(s) with w(x) ≤ 6 m, h(y) ≤ 4 m,(sum) L ≈ 25 m.  NuMI Near Hall Detector studies underway: t “pure scintillator planes” + planes of A: ton fiducial volume - cost O($3M) t liquid H 2 / D 2 (bubble chamber): large target technically feasible - safety requirements..?  With these detectors and a 1 year he_ and 2 year he_ exposure, we could measure the ratio (A/ D 2 ) of F 2 for x >.01 to better than 10% and ratio of xF 3 for x >.02 to better than 30% (better than 18 % for x >.02).


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