A High Statistics Neutrino-Nucleus Scattering Experiment in the NuMI Beam at Fermilab

A High Statistics Neutrino-Nucleus Scattering Experiment in the NuMI Beam at Fermilab

Jorge G. Morfín

Fermilab

Illinois Institute of Technology29 August 2002

NuMI Scattering Experiment - Jorge G. Morfín 2

OUTLINE

Facility: Beam Facility: Expected Event Rates Facility: MINOS Near Detector Hall

Detector Concept

Physics Topics to be Studied


NuMI Beamline on the Fermilab Site


NuMI Beamline Geometry

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


NuMI Neutrino Beam Configurations

Horn 1 position fixed - move target and horn 2 to change mean energy of beam.

Three “nominal” configurations: low-, medium-, high energy.

In addition, “pseudo-me” and “pseudo-he” beams. Horns left in le configuration and only target moved.

MINOS will run with a combination of configurations. It will be heavily weighted toward lower energy but also involve pme- and phe-beam running.


Neutrino Event Energy Distributionsand Statistics

Reasonably expect 2.5 x 1020 pot per year of NuMI running.

le-configuration: Events- (E>0.35 GeV) Epeak = 3.0 GeV, <E> = 10.2 GeV, rate = 200 K events/ton - year.

me-configuration: Events- Epeak = 7.0 GeV, <E> = 8.5 GeV, rate = 675 K events/ton - year pme rate = 540 K events/ton - year.

he-configuration: Events- Epeak = 12.0 GeV, <E> = 13.5 GeV, rate = 1575 K events/ton - year phe rate =

1210 K events/ton - year.

With E-907 at Fermilab to measure particlespectra from the NuMI target, expect to know neutrino flux to better than ± 5%.


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

Approved for 2 such cycles (3 year run) with 2.5x1020 protons/year: 860 K events/ton. <E> = 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


MINOS Parasitic Running: x, Q2 and W2

Events / ton

elastic+

resonance


Prime User: he Event Energy Distribution

Run he beam configuration only! <E> = 13.5 GeV

For example, 1 year neutrino plus 2 years anti-neutrino would yield:

1.5 M - events/ton0.9 M -

events/ton

DIS (W > 2 GeV, Q2 > 1.0 GeV2): 0.85 M events / ton

0.35 M events / ton

Shadowing region (x < 0.1):0.3 M events/ton


he- beam: x, Q2 and W2

Events / ton-year


NuMI Near Hall: Dimensions & Geometry

≈ 100 m undergroundLength: 45m - Height: 9.6m - Width: 9.5m

Length Available for New Detector: 26 m

Incoming angle: beam: 58 mr.


NuMI Beam Interacts Off-Module-Center

Wonderful - inviting - spotfor a new detector which could

use MINOS near detector as part of a muon ID/spectrometer!


A First Significant Step…Block Diagram

MINOSNear Detector

ScintillatorStrips

Planes ofC, Fe, Pb

2.5 cm thick iron plates alternating with scintillator strips 15 ton fiducial

volume

Recycler (permanent)Magnets

Side IDspectrometer

Forward IDSpectrometer

MagnetCoil


Detector: Conceptual DesignANL: John Arrington, Roy Holt, Dave Potterveld and Paul Reimer - FNAL: JGM

Fermilab Bright Booster Study - Spring 2001

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 = 1.0 ton (+MINOS) 2 planes Pb = 1.0 ton

Readout: mainly VLPC, perhaps also multi-anode PMT for TOF.

Use MINOS near detector as muon identifier / spectrometer.

2.0 m x 2.0 m x 2.0 m long

Scintillator Only

Scint. + Planes of C, Fe,W

Upstream Half

Downstream Half


Example of Event Profiles in Scintillator Detector

David Potterveld - ANL

CC: E = 4.04 GeV, x = .43, y = .37

“Elastic”: E = 3.3 GeV, x = .90, y = .08

CC: E = 11.51 GeV, x = ..34, y = .94

NC: E = 29.3 GeV, x = ..25, y = .46


Detector: Side -ID/Spectrometer

Without the side ID/Spectrometer we would lose 19 % of he-events and 25% of MINOS-parasitic events.

The E of lost events has ≈ 50% below 2 GeV. The < Eh> for these events ranges from 1.0 GeV for the le-beam to 1.6 GeV for the he-beam

We can use permanent magnets to ID

and measure P of the B = 3.8 KG. 6” x 4” x 1” cost $5.00!

These side detectors also function as a calorimeter for particles leaking out the side.


Scintillator/Fiber & VLPC R&D at Fermilab

Scintillation detector work at FermilabScintillation Detector Development Laboratory

Extruded scintillatorFiber characterization and test

Thin-Film facilityFiber processing: Mirroring and coatingsPhotocathode workDiamond polishing

Machine DevelopmentDiamond polishingOptical connector developmentHigh-density Photodetector packaging

(VLPC)

Triangles:1 cm base and transverse segmentation. Yields about 1 mm position resolution for mips

From D0 pre-shower test data

Polymer Dopant

Scintillator Cost < $ 5 / kg

Continuing development of D0 VLPC readout with $750K grant.

Produced D0-type arrays for detailed device analysis at low cost compared to D0

Goal: Demonstrate X10 cost reduction for VLPC.


New K2K Near Detector: Similar Concept

2 cm1cm

3m

3m

Particle identification using dE/dx information.


Off-axis Near Detector - Univ. of Rochester

Would be “near detector” for an off-axis neutrino oscillation experiment.

Lower <E> and narrower peaked E distribution yields x10 less events.

Main physics goal is to measure composition of neutrino beam and low-energy CC and NC cross-sections.

Proposed detector is constructed of scintillator bars (2 cm x 2 cm) in a 2m x 2m x 3m yielding a 1.9 m3 fiducial volume. Surrounded by 1m iron/scintillator sandwich on four sides and 2.4 m downstream muon ID/spectrometer.

Requires civil-construction to build “hall” off NuMI facility and extensive iron handling. About x10 cost of this experiment.


Add a Liquid H2/D2Target

H_2/D_2

MINOS Near

Fid. vol: r = 80 cm. l = 150 cm.

350 K CC evts in LH2 800 K CC evts in LD2 per year he- running.

Technically easy/inexpensive to build and operate.

Meeting safety specifications the major expense.


Detector: Event Rates; CC - E > 0.35 GeV

Event rates (2.5 x 1020 protons per year)

Parasitic Running Prime User Prime User (3 years) (1 year, he-) (2

year, he -)

CH 2.60 M 4.80 M 2.70 M

C 0.85 M 1.60 M 0.90 M

Fe 0.85 M 1.60 M 0.90M

Pb 0.85 M 1.60 M 0.90 M

LH2 0.35 M 0.20 M

LD2 0.80 M 0.45 M


Rough Costs

Scintillator (12.5 K channels) $50 K Fibers (12.5 K channels) $50 K Permanent Magnet Material (35 cm thick) $70 K VLPC

Boeing Tax $250 K VLPC $50/channel $625 K* Electronics $40/channel $500 K Cryogenics $200 K

SUM $1575 K

SUM = $1750 K x 2 (assembly) $ 3.5 M


-Scattering Physics Topics with NuMI Beam Energies and Statistics

Measure during initial MINOS exposure Quasi-elastic neutrino scattering and associated form-factors. Spin of the strange quark through elastic scattering. Far more accurate with many

fewer assumptions than charged lepton results for s. Nuclear effects involving neutrinos.

Need antineutrinos for (maximal) physics output sin2W via the ratio of NC / CC (as well as d/dy from -e scattering) to check the recent surprising

NuTeV result. Nuclear effects for valence and sea quarks. Parton distribution functions (pdf), particularly in the high-xBj region.

Leading exponential contributions of pQCD. Charm physics including the mass of the charm quark mc (improved accuracy by an order of

magnitude, Vcd, s(x) and, independently, s(x.).

Need excellent particle identification Strange particle production for Vus, flavor-changing neutral currents and measurements of

hyperon polarization. Resonance production region (very poorly studied up to now).


(Quasi-)elastic Scattering

World sample is still fairly miserable statistics!

Garvey et al showed that +p elastic scattering quite sensitive to the spin carried by s within proton.

Measure s cleanly in scattering Radiative corrections small. Past experiments (BNL, LSND)

We can significantly reduce systematic errors by measuring the ratio: +p +p

+n +p


Measuring s -- J. Arrington, R. Holt, D. Potterveld and P. Reimer - ANL C. Horowitz and R. Tayloe - Indiana U.

Status s ≈ - 0.12 ± 0.03, BUT: Large x --> 0 extrapolation and one has to assume SU(3) symmetry

Neutrino NC Scattering yields s directly

Measure R to ± 0.03 yields s to ± 0.02

R. Holt - ANL


Measurement of the Axial Form Factor

Needed to control systematic errors for extraction of s.

Accurate determination of MA possible with charged current quasi-elastic events.

Search for non dipole Search for non dipole behavior? Look at large Qbehavior? Look at large Q22 range: 0.2 - 6+ GeVrange: 0.2 - 6+ GeV22..


Is Neutron Background in the NuMI near hall a problem?

Particle Flux (10-5 cm-2)--------------------------------------------------- Eth (MeV) LE ME HE--------------------------------------------------- n 0 11.560 29.130 76.320 0.1 2.447 5.613 13.000 1 1.745 3.812 8.404 20 1.088 2.490 4.551 100 0.472 1.112 1.992--------------------------------------------------- h± 0.2 0.537 1.234 3.118 20 0.529 1.105 2.938 100 0.395 1.078 2.454--------------------------------------------------- 0.2 38.010 80.690 204.600 20 2.557 4.472 12.570 100 0.913 1.304 4.208--------------------------------------------------- e+- 0.2 3.340 4.880 12.540 20 1.246 2.144 4.921 100 0.403 0.703 2.209--------------------------------------------------- 0.2 3.542 6.753 11.740 20 3.450 6.690 11.580 100 3.448 6.560 11.320---------------------------------------------------

Using MARS Monte Carlo. M. Kostin and N. Mokhov determined flux of non- particles at site of new detector.

Multiply the relevant number by fiducial volume to determine total track length within fid. vol.

For example: for neutrons E > 100 MeV with the le-beam, 14 cm of track length in fiducial volume per spill.

Need to fold Ep from n+p n+p with incoming neutron spectrum. Further reduction by surrounding detector with neutron absorbing material and making kinematic cuts possible.


Studying Charged-Current Resonant Processes

Data from a number of experiments exists Pure I=3/2 channel ~solid Agreement less than spectacular for

mixed isospin channels

Description by Rein-Sehgal model

Nuclear effects: Axial form-factor? Nuclear medium effects on Delta inelastic scattering Pion final state reactions?

n–p0

n–n+

p–p+


Studying Neutral Current Resonant Processes

The World’s sample!!

ANL p n + (7 events) n n 0 (7 events)

Gargamelle p p 0 (178 evts) p p 0 (139 evts)

BNL p p –/ p p +

K2K

Starting a careful analysis of single 0 production.

0 angle

P 0 (MeV/c)

K2K Preliminary1-kton, single 0’s


Studying Nuclear Effects with Neutrinos

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.


Are Nuclear Effects the SAMEfor and e/ Scattering

Shadowing with NOT the same as with charged leptons. Axial vector component of current Shadowing off valance quarks different than off sea quarks????

No reason to expect the EMC effect to be the same with axial vector current involvement. Particularly if pion cloud is responsible for the effect

All such IVB effects are contained in nuclear parton distribution functions (Kumano, Eskola et al.) for parton level interactions.


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 (E906 will yield improved statistics) 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


Nuclear Parton Distribution Functions

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?

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

b hep-ph/9807297 c hep-ph/0103208


A Specific Look at Scattering Nuclear Effects:Shadowing

Q2 = 15 GeV2

•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.


Predicted Scattering Nuclear Effects compared to e/ Scattering

hep-ph/9812532


Experimental Results in Scattering: Nuclear Effects?

Bubble Chamber:Ne/D2

FNAL E-545

CERN BEBC


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.


Examples: Expected Statistical Errors-MINOS Parasitic( running only)

Ratio Fe/C: Statistical Errors xBj MINOS MINOS

2-cycle DIS

0.0 - .01 1.8 % xxx

.01 - .02 1.4 10 %

.02 - .03 1.3 6

.03 - .04 1.2 4

.04 - .05 1.1 3

.05 - .06 1.1 2.6

.06 - .07 1.0 2.3

.1.01.0010.5

0.6

0.7

0.8

0.9

1.0

Pb/C

Fe/C

Kulagin Predictions: Fe/C and Pb/C - ALL EVENTS - 2-cycle

x

R (A/C)


Examples: Expected Statistical Errors - he Running

Ratios (he, 1 year , DIS): Statistical Errors xBj Fe/ LD2 Fe/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

High xBj (he, 1 year, DIS): Statistical Errors

xBj CH LH2 LD2 .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

Taking ratios: most beam systematics cancel.

Assume relative target systematics are the same as Tevatron Muon Expt. O (1 %).

Ratios (he, 1 year 2 year , DIS): Statistical ErrorsNo optimization of implies very conservative errors


Another Open Nuclear Effects Question: Behavior of F2 as x --> 1.0 in Nuclear Environment

Need to add more than Fermi gas model to simple nucleon model to reproduce behavior of F2 at high x in nucleus.

Few-nucleon-correlation and multi-quark models allow quarks to have higher momentum ---> high x tail with F2 e

- ax . Analyses by SLAC, BCDMS, CEBAF and CCFR with values of a varying 7 < a < 17

in various kinematical regions and targets. BCDMS and CCFR are in similar kinematical regions:

BCDMS ( + C): a = 16.5 ± 0.5 CCFR ( + Fe): a = 8.3 ± 0.7 ± 0.7(syst.)

Is a dependent on nucleus? Is a dependent on vs. Recent* e + Fe from Jlab: a = 16!

hep-ex/9905052


Extracting Parton Distribution Functions:What Can We Learn With All Six Structure Functions?

Does s = s and c = c over all x? If so.....

F 2Ν (x,Q2 ) =x u+ u + d+ d+2 s + 2c[ ]

F 2Ν (x,Q2 ) =x u+ u + d+ d+2s+ 2 c[ ]

xF 3Ν (x,Q2 ) =x u+ d - u - d - 2 s+ 2c[ ]

xF 3Ν (x,Q2 ) =x u+ d - u - d +2s - 2 c[ ]

F2 - xF3

=2 u + d+ 2 c( )=2U + 4 c

F2 - xF3

=2 u + d+ 2 s( )=2U + 4 s

xF3 - xF3

=2 s+ s( ) − c+ c( )[ ] =4 s - 4 c

Using Leading order expressions:

Recall that 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.


Six Structure Functions for Maximal Information on PDF’s

d A

dxdQ2= GF

2

2x12

F 2A (x,Q2 ) + xF3

A (x,Q2 )( ) +1 −y( )2

2F 2A (x,Q2 ) −xF 3

A (x,Q2 )( )⎡

⎣⎢⎤

⎦⎥

d A

dxdQ2= GF

2

2x12

F 2A (x,Q2 ) −xF 3

A (x,Q2 )( ) +1−y( )2

2F 2A (x,Q2 ) + xF3

A (x,Q2 )( )⎡

⎣⎢⎤

⎦⎥

,x Q2 , (1− )y 2( )G2 2x

X = 0.1 - 0.125Q2 = 2 - 4 GeV2

+ y2 FL

1.00.90.80.70.60.50.40.30.20.10.00.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

Neutrino

AntiNeutrino

NuFact_R + .5% Syst

NuFact_R + .5% Syst

MISCINT_R + 2% Syst

MISCINT_R + 2%Syst

R = R_Whitlow


The Ultimate NuMI Neutrino Scattering FacilityNickolas Solomey

Scintillator Strips

MINOS Near

H_2/D_2

Additional Scintillator Tracking

Additional Scintillator Tracking

Side Muon ID (Steel + Scintillator)

Side Muon ID (Steel + Scintillator)

TOF

Magnet

Electromagnetic Calorimeter

Electromagnetic Calorimeter

Electrom

agnetic Calorim

eter

Muon IDSteel + Scint


Proposal for a Study of -Nucleus Scatteringin the NuMI Beam

Collaboration of nuclear and particle physics communities.

Currently indicating interest in this experiment: Argonne National Lab, Colorado, Ecole Polytechnique, Fermilab,

Illinois, IIT, Indiana, Los Alamos National Lab, Marsseilles, Rutgers, Tuft - (Athens, BNL, College de France, Pittsburgh)

Goal is to sign up many MINOS collaborators and add more NP. Submit EOI/LOI to the Fermilab PAC in late 2002.

Start running parasitically with MINOS in 2005 time scale. Neutrinos only

Run as prime users starting as early as 2008. Higher Energy running with and


Summary

NuMI Beam is Intense: yielding ≈ 860 K events/ton during MINOS approved run* yielding ≈ 1.6 M events/ton-year in the he-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 Physics: cross section measurements including quasi-elastic neutrino scattering and associated form-factors. spin contribution of strange quark nuclear effects of different than eNuclear effects on valance- different than sea-quarks sin2W via the ratio of NC / CC

PDFs particularly high-x, study of leading exponentials of pQCD strange particle production

NuMI Near Hall Detector studies underway: “solid scintillator” + planes of A: 3 - 5 ton fiducial volume - cost O($3M) liquid H2 / D2 (bubble chamber): large target technically feasible - safety requirements….?

Can study all of the listed physics topics during MINOS run and/or in a 3 years (+ ) he run Real and growing interest from both the NP and EPP communities,


INVITATION!

JOIN THE FUN!!

Documents

A High Statistics Neutrino-Nucleus Scattering Experiment in the NuMI Beam at Fermilab