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Recent Developments in Nuclear Forces Lecture

This lecture discusses recent developments in nuclear forces, including new ideas and revisions of chiral forces up to N3LO and the need to go beyond N3LO. It also explores two- and three-nucleon forces at N4LO and the NN interaction at N5LO, providing an outlook on future advancements.

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Recent Developments in Nuclear Forces Lecture

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  1. 2016 Nuclear Physics School June 20 – 24, 2016 APCTP Headquarters, Pohang Nuclear Forces- Lecture 7 - Recent Developments R. Machleidt University of Idaho R. Machleidt Nuclear Forces - Lecture 7 Recent (Pohang 2016) Nuclear Forces - Lecture 6 NF from EFT II (Pohang 2016) 1

  2. Nuclear Forces- Overview of all lectures - • Lecture 1: Historical perspective • Lecture 2: Properties and phenomenology of the nuclear force • Lecture 3: The meson theory of nuclear forces • Lecture 4: QCD and nuclear forces; the symmetries of low-energy QCD • Lecture 5: Effective field theory (EFT) for low-energy QCD and nuclear two-body forces • Lecture 6: Nuclear many-body forces from chiral EFT • Lecture 7: Recent Developments Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  3. Outline • “New” ideas and revisions of chiral forces up to N3LO • The need to go beyond N3LO • Two- and three-nucleon forces at N4LO • The NN interaction at N5LO • Outlook Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  4. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  5. Status A.D. 2000 Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  6. But: Recent revival: Ekstroem et al., 2013+ NNLOopt NNLOsat NNLOsep NNLOsim R. Machleidt Nuclear Forces - Lecture 7 Recent (Pohang 2016) 6

  7. Status A.D. 2003 R. Machleidt Nuclear Forces - Lecture 7 Recent (Pohang 2016) 7

  8. But also here: Recent revival: Epelbaum et al., 2015 “New Generation of Potentials” R. Machleidt R. Machleidt Nuclear Forces - Lecture 7 Recent (Pohang 2016) Chiral nuclear forces PKU-CUSTIPEN, August 2, 2015 8 8

  9. Why revival at N3LO? Problems with the old Bochum potentials: Bad fit, bad chi2 Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  10. Problems with the new Bochum potentials • Fitted to phase shifts. As pointed out correctly by the Nijmegen group some 20 years ago, phase shift chi2 can be very misleading concerning the true reproduction of the NN data. • Comparison is made to just one data set: Abfalterer et al. 2001, 78 np total cross section data. Even the craziest NN potential can fit one data set. The point is to fit all 4000+ NN data. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  11. Problems with the new Bochum potentials,continued • The potentials use local cutoffs: But potentials with local cutoffs stay non-zero up to several GeV, far beyond the validity of chiral EFT. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  12. But also here: Recent revival: Epelbaum et al., 2014 “New Generation of Potentials” Not so “new” and Not a “Generation”. R. Machleidt R. Machleidt R. Machleidt Nuclear Forces - Lecture 7 Recent (Pohang 2016) Chiral nuclear forces PKU-CUSTIPEN, August 2, 2015 Chiral nuclear forces PKU-CUSTIPEN, August 2, 2015 12 12 12

  13. Status A.D. 2010 R. Machleidt R. Machleidt Nuclear Forces - Lecture 7 Recent (Pohang 2016) Chiral nuclear forces PKU-CUSTIPEN, August 2, 2015 13 13

  14. Evaluate the current status of results From applications of chiral forces. • 2NFs and 3NFs up to N3LO have been applied in nuclear few- and many-body systems. • In general, quite a bit of success, but some persistent problems remain. • In the few-body sector: Ay puzzle, N-d break-up, … Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  15. Evaluate current status. Anything left to do in the nuclear force business? • Current status: 2NFs and 3NFs up to N3LO are applied in nuclear few- and many-body systems. • In general, quite a bit of success, but some persistent problems remain. • In the few-body sector: Ay puzzle, N-d break-up, … • Light nuclei: Spectra not perfect. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  16. Evaluate current status. Anything left to do in the nuclear force business? • Current status: 2NFs and 3NFs up to N3LO are applied in nuclear few- and many-body systems. • In general, quite a bit of success, but some persistent problems remain. • In the few-body sector: Ay puzzle, N-d break-up, … • Light nuclei: Spectra not perfect. • Intermediate nuclei: Overbinding. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  17. Ground-state energies from O-16 to Sn-132 obtained in CC with 2NF + 3NF From S. Binder et al., PLB 736, 119 (2014). Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  18. Evaluate current status. Anything left to do in the nuclear force business? • Current status: 2NFs and 3NFs up to N3LO are applied in nuclear few- and many-body systems. • In general, quite a bit of success, but some persistent problems remain. • In the few-body sector: Ay puzzle, N-d break-up, … • Light nuclei: Spectra not perfect. • Intermediate nuclei: Overbinding. • Convergence of the chiral expansion in the many-body system? Not converged at N3LO (F. Sammarruca et al., PRC 91, 054311 (2015)). Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  19. N3LO N2LO NLO Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  20. Because of the problems just pointed out, improvement of current nuclear forces is called for. • How? • Go to next order! • That is: Turn to N4LO. • What can we expect from N4LO? • Does N4LO have anything to offer we were not offered before? Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  21. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  22. R. Machleidt Nuclear Forces - Lecture 7 Recent (Pohang 2016) 22

  23. R. Machleidt Nuclear Forces - Lecture 7 Recent (Pohang 2016) 23

  24. Krebs et al. (2012, 2013) 1-loop graphs: 5 topologies 2PE 2PE-1PE Ring Contact-1PE Contact-2PE Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  25. Krebs et al. (2012, 2013) 1-loop graphs: 5 topologies 2PE 2PE-1PE Ring Contact-1PE Contact-2PE Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  26. 3NF contacts at N4LO Girlanda, Kievsky, Viviani, PRC 84, 014001 (2011) Krebs et al. (2012, 2013) 1-loop graphs: 5 topologies 2PE 2PE-1PE Ring Contact-1PE Contact-2PE Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  27. All possible 20 isospin-spin-momentum/position structures occur in the 3NF at N3LO! Epelbaum et al., Eur. Phys. J. A51, 26 (2015) Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  28. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  29. Because of the problems demonstrated, improvement of current nuclear forces indicated • How? • Go to next order! • That is: Turn to N4LO. • What can we expect from N4LO? • Does N4LO have anything to offer we were not offered before? Oh yes! All 3NFs you have ever dreamed of! Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  30. What else is there at N4LO? Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  31. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  32. N4LO 2NF Contributions Entem, Kaiser, Machleidt, Nosyk, PRC 91, 014002 (2015) Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  33. N4LO effects on NN scattering in peripheral partial waves From Entem, Kaiser, Machleidt, Nosyk, PRC 91, 014002 (2015) Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  34. Using LECs from pi-N Analysis at order four. From Entem, Kaiser, Machleidt, Nosyk, PRC 91, 014002 (2015) Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  35. How about convergence? Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  36. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  37. N5LO 2NF Contributions Entem, Kaiser, Machleidt, Nosyk, arXiv:1505.03562 (May 2015) Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  38. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  39. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  40. Convergence at N5LO Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  41. At N5LO: Super-accurate Potential possible Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  42. Map of Chartered and Unchartered Waters Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  43. Conclusions • The chiral force market has become divers: “new” forces at NNLO and N3LO; Be critical! • N3LO won’t solve all our problems. • Turn to N4LO: Complete set of 3NFs and new 3NF contacts. • 2NF at N4LO very quantitative including the peripheral waves (N4LO NN pots becoming available). • Convergence of NN occurs at N5LO. • There are now enough forces on the market to keep you either busy or confused. Nuclear Forces - Lecture 7 Recent (Pohang 2016)

  44. The End Nuclear Forces - Lecture 7 Recent (Pohang 2016)

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