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NuPAC 20051 Physics at the proton and neutron drip lines Theoretical perspectives Angela Bonaccorso.

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Presentation on theme: "NuPAC 20051 Physics at the proton and neutron drip lines Theoretical perspectives Angela Bonaccorso."— Presentation transcript:

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2 NuPAC 20051 Physics at the proton and neutron drip lines Theoretical perspectives Angela Bonaccorso

3 NuPAC 20052 Why do the driplines exist? Because there are unstable nuclei… Because the neutron is unstable… Because it is heavier than the proton… The neutron is unstable in order for the hydrogen atom and nature to be stable.

4 NuPAC 20053 Let us see how the “center-left” Physics needs ISOLDE and even an upgrade of it.

5 NuPAC 20054 at Nuclei at the driplines They are what the reaction mechanism makes them to be… Interplay between structure and reaction bound vs. continuum aspects…bound vs. continuum…stronger than in any other part of the nuclear chart. A perfect balance between short and long range parts of the nuclear interaction. Unbound Nuclei Unbound Nuclei

6 NuPAC 20055 reaction mechanism 13 Be: an example of creation by the reaction mechanism 14 Benuclear and Coulomb breakup: 14 Be nuclear and Coulomb breakup: GANIL (K. Jones thesis, 2000). 14 C+ 11 B 14 C+ 11 B multinucleon transfer: (Berlin Group,1998). 18 O fragmentation 18 O fragmentation MSU (Thoennessen, 2001) n-core relative velocity spectra. 14 B 14 B fragmentation: GANIL ( Lecouey, Orr) (2002). GSI (U. Datta Pramanik)( 2004).Unpublished 14 Be 14 Be nuclear breakup: RIKEN (Nakamura, Fukuda) (2004).Unpublished 14 Be 14 Be nuclear breakup, GSI ( Simon ), 287AMeV, n-core angular correlation transfer to the continuumtransfer to the continuum: 12 Be (d,p) RIKEN ( Korsheninnikov ) (1995). cf. 10 Li at REX-ISOLDE H.B. Jeppesen, et al., NP A748, (2005)374

7 NuPAC 20056 2s d5/2 p1/2 p3/2 1s1/2 2s d5/2 p1/2 p3/2 1s1/2 d5/2 p1/2 2s p3/2 1s1/2     ........ 14 B g.s. = 2 - =  p3/2+ 2s 12 Be g.s. = 0 + 14 Be g.s. = 0 + (?)....  .... d3/2 2s d5/2 p1/2 p3/2 1s1/2 inversion threshold

8 NuPAC 20057 Potential corrections due to the particle-vibration coupling ( N. Vinh Mau and J. C. Pacheco, NPA607 (1996) 163. also T. Tarutina, I.J. Thompson, J.A. Tostevin NPA733 (2004) 53 ) can be modeled as: … can be modeled as: n+ 12 Be: d3/2 2s d5/2 p1/2 p3/2 1s1/2 inversion threshold U( r ) = V WS + V so +  V  V ( r ) = 16  e (r-R)/a / (1+e (r-R)/a ) 4

9 NuPAC 20058 s-state potential:long range added p-state potential:long range subtracted

10 NuPAC 20059 G. Blanchon, A. B., D. M. Brink and N. Vinh Mau, Unbound exotic nuclei studied by projectile fragmentation reactions. IFUP-TH 29/2004: submitted to NPA 12 Be (d,p) G. Blanchon, A. B. and N. Vinh Mau Unbound exotic nuclei studied by transfer to the continuum reactions Nucl. Phys. A739 (2004) 259. Final s-state bound vs continuum

11 NuPAC 200510 Bound to unbound transitions

12 NuPAC 200511 Core excitation simulated by imaginary part of n-core optical potential

13 NuPAC 200512 effective range theory (1 0 order) k cotan  = - 1 asas + 1 2 r o k 2

14 NuPAC 200513 All aspects of the nuclear interaction discussed in structure models: short range vs. long range, real vs. imaginary…volume vs. surface… amplified at the driplines

15 NuPAC 200514 Momentum Distributions Momentum Distributions Reaction Cross Sections Reaction Cross Sections Spin-orbit coupling effects 19 C+ 9 Be 20 88 A.MeV J.Enders et al.,

16 NuPAC 200515 Spectroscopic factors from knockout reactions (P.G.Hansen et al.) Spectroscopic factors from excited states of fragment. l of nucleon from momentum distribution of fragment. ∑

17 NuPAC 200516 Elastic Scattering Elastic Scattering Elastic Scattering and Optical Potentials of Halo Nuclei GANIL data P. Russel-Chomaz, unpublished 11 Be 10 Be

18 NuPAC 200517 A.A. Ibraheem and A. B., Recoil effects on the optical potentials of weakly bound nuclei Nucl. Phys. A748 (2005) 414. A. B. and F. Carstoiu Optical potentials of halo and weakly bound nuclei Nucl. Phys. A706 (2002) 322.

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20 NuPAC 200519   ≈    i   ћ   ≈  f -  i  ћ  v decay length of initial wave function adiabaticity parameter of Coulomb excitation theory

21 NuPAC 200520 …see also a classical reference Effect of the breakup channel on 11Li elastic scattering, J.S. Al-Khalili, Nucl. Phys. A 581 (1995) 315-330 …and references therein. …and one of the most recent at 10A.MeV

22 NuPAC 200521 For the structure aspect…see also http://www.df.unipi.it/~angela/talks.html http://www.df.unipi.it/~angela/finalprogram.html “Evolution of nuclear structure, shapes, and fission” Structure of proton-radioactive nuclei Lídia S Ferreira and Enrico Maglione 2005 J. Phys. G: Nucl. Part. Phys. 31 S1569-S1572

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24 NuPAC 200523 Conclusions and Outlook phenomenological energy dependent nuclear potential bound scattering. Study of dripline nuclei will lead us to the best possible phenomenological energy dependent nuclear potential for bound and scattering states. My guess for the future My guess for the future: We will have to redefine the n-n interaction in terms ”n-body“ of a ”n-body“ interaction ( 3-body terms are already necessary !! ). Paring ( n-p ) will be understood ( I hope!! ) on a effective field theories ?? microscopic basis…( effective field theories ?? )..“Exotic” threshold characteristics of dripline nuclei enhanced by low energy experiments at E inc ≤ 20A.MeV.

25 NuPAC 200524 Hi Gregers, would you agree…? Spectroscopic Factors, Trento 04 UPGRADE ISOLDE !!

26 NuPAC 200525 check of sudden approximation E inc: independent  if : important S and S correspond to different phase shifts ‾ Broglia & Winther book transfer to the continuum projectile fragmentation:inelastic excitation transfer inelastic Appendix I: transfer vs. inelastic

27 NuPAC 200526 Appendix II: potential from phase shift.


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