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Few Nucleon Studies at TUNL

Few Nucleon Studies at TUNL. 1. The Nd A y Puzzle: (a) Refinement of NN 3 P J Phase Shifts: high-precision np and pp A y measurements (b) Complete Picture of Energy Dependence of Discrepancy: new Nd A y measurements

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Few Nucleon Studies at TUNL

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  1. 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

  2. Nd Ay Puzzle: Refinement of 3PJ np Phase Shifts Proposal:Measurement of Ay(q) for np Elastic Scattering at 7.6 and 18.5 MeV PI:W. Tornow Participants C.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

  3. Status of Low-Energy np 3PJ Phase Shifts (1988) (1994) Experimental Details: 7.6 MeV 18.5 MeV Number data points: 15 15 Accuracy (±3%): ±0.0003 ±0.0005 Accelerator: tandem tandem Neutron Source: 2H(d,n) 2H(d,n) Target Area: NSSA NSSA Counting time: 120 days 40 days

  4. Nd Ay Puzzle: Refinement of 3PJ pp Phase Shifts Proposal:Measurement of Ay(q) for pp Elastic Scattering at 6.14 and 15.6 MeV PIs:H.J. Karwowski and E.J. Ludwig Participants T.C. Black, UNC-Wilmington T.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)

  5. Status of Low-Energy pp 3PJ Phase Shifts

  6. Experimental Details of pp Ay Measurements Experimental Details: 6.14 MeV 15.6 MeV Number data points: 10 10 Accuracy (±5%): ±0.00005 ±0.00005 Accelerator: tandem tandem Target Area: Gas Jet Gas Jet

  7. Proposal:Measurement of Ay(q) for nd Elastic Scattering at 0.65, 19.0, 28.0 and 35.0 MeV Nd Ay Puzzle: Complete Energy dependence of nd Ay Discrepancy PIs:W. Tornow and G.J. Weisel (Penn State at Altoona) Participants C.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)

  8. En = 3 MeV 0 60 120 0 60 120 180 3NF in NNLO EFT Calculations E. Epelbaum, A. Nogga, W. Gleockle, H. Kamada, Ulf-G. Meiner and H. Witała, arXiv:nucl-th/0208023 v1 13 Aug 2002 3NF OPE Contact TPE

  9. NLO NNLO EFT Calculations En = 3 MeV En = 10 MeV En = 65 MeV 120 0 60 120 180 0 60

  10. Energy Dependence of Discrepancy in Nd Ay Puzzle

  11. 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

  12. 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

  13. PIs:H.J. Karwowski and E.J. Ludwig LE pd Ay Measurements Participants T.C. Black, UNC at Wilmington T.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 Pisa M. Viviani, INFN, Sezione di Pisa Experimental Details: 650 keV 1.0 MeV Number data points: 10 10 Accuracy : ±0.0005 ±0.0005 Accelerator: tandem tandem Target Area: Gas Jet Gas Jet

  14. Proposal to Measure A0y for p3He Elastic-Scattering with a Polarized 3He Target PI:T.B. Clegg Participants H.J. Karwowski, UNC-Chapel Hill E.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 Pisa M. Viviani, INFN, Sezione di Pisa

  15. The Ay Puzzle in the 4N system

  16. p3He Elastic Scattering: Comparison of Ay0 and A0y

  17. Sensitivity of p3He to NN 3PJ Potential

  18. Verification of Selected Neutron-Deuteron Breakup Cross-Section Data PIs:C.R. Howell W. Tornow and R.L. Walter Participants A. 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)

  19. Main Discrepancies in nd Breakup  1. Space Star Anomaly 2. nn FSI 1S0 ann • (a) p- + 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)  3. 0° proton energy spectrum 1S0 ann 4. nn QFS (recent data from von Witsch’s group in Bonn)

  20. Space Star Anomaly nd data, TUNL 1996 nd data, Erlangen Univ. 1988 pd data, Univ. Cologne 1991 3.0 d5s/dW1dW2dS (mb/sr2MeV) 2.0 1.0

  21. Energy Dependence

  22. Current Setup: coincidence geometry

  23. 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.

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