Few Nucleon Studies at TUNL

1. The Nd Ay Puzzle:

(a) Refinement of NN 3PJ Phase Shifts: high-precision np and pp Ay measurements (b) Complete Picture of Energy Dependence of Discrepancy: new Nd Ay measurements

2. The Ay Puzzle in the 4N system: measurements with polarized 3He target

3. Discrepancies in nd Breakup: new cross-section measurements

Nd Ay Puzzle: Refinement of 3PJ np Phase Shifts

Proposal: Measurement of Ay() for np Elastic Scattering at 7.6 and 18.5 MeV

PI: W. Tornow

ParticipantsC.R. Howell, Duke Univ.J.H. Kelley, NC State Univ.R.L. Walter, Duke Univ.

A. Crowell (Postdoc)J. Deng (Graduate Student)M. Kiser (Graduate Student)R. Macri (Graduate Student/Postdoc)

B.J. Crowe (NC Central University)R.S. Pedroni (NC A&T State University)G.J. Weisel, Penn State at Altoona

Status of Low-Energy np 3PJ Phase Shifts(1988)

(1994)

Experimental Details: 7.6 MeV 18.5 MeVNumber data points: 15 15 Accuracy (±3%): ±0.0003 ±0.0005Accelerator: tandem tandemNeutron Source: 2H(d,n) 2H(d,n)Target Area: NSSA NSSACounting time: 120 days 40 days

Nd Ay Puzzle: Refinement of 3PJ pp Phase Shifts

Proposal: Measurement of Ay() for pp Elastic Scattering at 6.14 and 15.6 MeV

PIs: H.J. Karwowski and E.J. Ludwig

ParticipantsT.C. Black, UNC-WilmingtonT.B. Clegg, UNC-Chapel Hill

M.S. Boswell (Graduate Student)T.V. Daniels (Graduate Student)B.M. Fisher (Graduate Student)D. Gupta (Postdoc)T. Katabuchi (Postdoc)D.S. Leonard (Graduate Student)

Status of Low-Energy pp 3PJ Phase Shifts

Experimental Details of pp Ay Measurements

Experimental Details: 6.14 MeV 15.6 MeVNumber data points: 10 10 Accuracy (±5%): ±0.00005 ±0.00005Accelerator: tandem tandemTarget Area: Gas Jet Gas Jet

Nd Ay Puzzle: Complete Energy dependence of nd Ay Discrepancy

Proposal: Measurement of Ay() for nd Elastic Scattering at 0.65, 19.0, 28.0 and 35.0 MeV

PIs: W. Tornow and G.J. Weisel (Penn State at Altoona)

ParticipantsC.R. Howell, Duke Univ.J.H. Kelley, NC State Univ.D.M. Markoff, NC State Univ.R.L. Walter, Duke Univ.

A. Crowell (Postdoc)J. Deng (Graduate Student)M. Kiser (Graduate Student)R. Macri (Graduate Student/Postdoc)

B.J. Crowe (NC Central University)R.S. Pedroni (NC A&T State University)

H. Witała (Jagellonian Univ., Cracow, Poland)W. Glöckle (Univ. of Bochum, Bochum, Germany)

3NF in NNLO EFT CalculationsE. Epelbaum, A. Nogga, W. Gleockle, H. Kamada, Ulf-G. Meiner and H. Witała, arXiv:nucl-th/0208023 v1 13 Aug 2002

3NF

TPE OPE Contact

En = 3 MeV

0 60 120 0 60 120 180

EFT Calculations

En = 3 MeV

NLO NNLO

En = 10 MeV

En = 65 MeV

0 60 120 1800 60 120

Energy Dependence of Discrepancy in Nd Ay Puzzle

Experimental Details of LE nd Ay Measurements

Experimental Parameters

Tandem Accelerator NTOF Target Room En = 650 keV 7Li(p,n) source reaction Ay = ±0.001 Counting time: 25 days

Experimental Details of HE nd Ay Measurements

Experimental Parameters

Tandem Accelerator Neutron Shielded Source Area En = 19, 28 and 35 MeV 2H(d,n) and 3H(d,n) source reactions Ay = ±0.005 Counting times: 40 days at 19 MeV 60 days at 28 MeV 60 days at 35 MeV

LE pd Ay MeasurementsPIs: H.J. Karwowski and E.J. Ludwig

ParticipantsT.C. Black, UNC at WilmingtonT.B. Clegg, UNC-Chapel Hill

M.S. Boswell (Graduate Student/MS work)T.V. Daniels (Graduate Student)B.M. Fisher (Graduate Student)D. Gupta (Postdoc)T. Katabuchi (Postdoc)D.S. Leonard (Graduate Student)

A. Kievsky, INFN, Sezione di PisaM. Viviani, INFN, Sezione di Pisa

Experimental Details: 650 keV 1.0 MeVNumber data points: 10 10 Accuracy : ±0.0005 ±0.0005Accelerator: tandem tandemTarget Area: Gas Jet Gas Jet

Proposal to Measure A0y for p3He Elastic-Scattering with a Polarized 3He Target

PI: T.B. Clegg

ParticipantsH.J. Karwowski, UNC-Chapel HillE.J. Ludwig, UNC-Chapel Hill

M.S. Boswell (Graduate Student)T.V. Daniels (Graduate Student/MS project)B.M. Fisher (Ph.D. thesis project)D. Gupta (Postdoc)T. Katabuchi (Postdoc)D.S. Leonard (Graduate Student)

A. Kievsky, INFN, Sezione di PisaM. Viviani, INFN, Sezione di Pisa

The Ay Puzzle in the 4N system

p3He Elastic Scattering: Comparison of Ay0 and A0y

Sensitivity of p3He to NN 3PJ Potential

Verification of Selected Neutron-Deuteron Breakup Cross-Section Data

PIs: C.R. Howell W. Tornow and R.L. Walter

ParticipantsA. Crowell (Postdoc)J. Deng (Ph.D. thesis project)M. Kiser (Graduate Student)R. Macri (Graduate Student/Postdoc)

C. Jackson (NC A&T State University)R.S. Pedroni (NC A&T State University)B.J. Crowe (NC Central University)

W. von Witsch (Univ. of Bonn)

H. Witała (Jagellonian Univ., Cracow, Poland)W. Glöckle (Univ. of Bochum, Bochum, Germany)

1. Space Star Anomaly

2. nn FSI

Main Discrepancies in nd Breakup

1S0 ann

3. 0° proton energy spectrum 1S0 ann

(a) - + d n + n + p ann = -18.6 ± 0.3 ± 0.3 fm (PSI, 1984 and 1987 and LAMPF, 1998)

(b) n +d n + n + p TUNL: ann = -18.6 ± 0.5 fm (1999)

Bonn: ann = -16.3 ± 0.4 fm (2000)

4. nn QFS (recent data from von Witsch’s group in Bonn)

Space Star Anomaly

1.0

2.0

3.0

d5 /d

1d

2d

S (m

b/sr

2 MeV

) nd data, TUNL 1996nd data, Erlangen Univ. 1988pd data, Univ. Cologne 1991

Energy Dependence

Current Setup: coincidence geometry

Proposed Setup: recoil geometry

Systematic Differences with present setup:

(1) Measured cross section only depends on relative efficiency of one neutron det. (2) Only modest correction for neutron attenuation (3) Need correction for neutron loss when both neutrons are in solid angle of det.

(4) Can perform simultaneous measurements of identical configurations using recoil-geometry setup with coincidence-geometry setup behind it.