Neutron�skin�structure�and�shell�evolution of�weakly�bound�neutron�rich�EURISOL�nuclei� in�coupled�reaction�channel�studies Physics &�Instrumentation�,�Firenze,�14�18�January 2008 ρ � ,� ρ � Structure�studies at the�drip�lines :�exemples,�+�exp�theory GOAL�with EURISOL:�extended systematics of�neutron�rms radius�and�of neutron�excitation along isotopic chains Probe�the�structure�&�spectroscopy at large�isospin � Measure unbound states� � detection devices Requirements for�a�new�experimental set�up NEED�FOR�AN�IMPROVED�THEORETICAL�FRAMEWORK�OF�STRUCTURE�AND�REACTIONS NEED�FOR�AN�IMPROVED�THEORETICAL�FRAMEWORK�OF�STRUCTURE�AND�REAC TIONS ��������������������� �����������������������
Nuclear�structure�towards�the�drip�lines�:�phenomena�to�explore�&�to�understand ����������������������� ���������������� � Drip�lines:��limit of�nuclear binding,�large�isospin Exploration:��new�exotic structures� � neutron�skin Tests:�nuclear modelling &�interactions��V NN (T z ) Change�in�shell�structure New�magic�numbers Neutron�skins Local�properties�(N,Z) Weakly�bound�states�? Continuum� �������� ? halo,clusters Isospin dependence�? 2008�:�what is known ? Neutron halo skin 2016�:�area�to�explore�? 6 He 8 He 4 He 4 He ��������������������� �����������������������
���� ���� Nuclear landscape towards the�drip�lines (# � " � � � �( � ! � �� �� #* � �� # )� %� �� ## �� � �� " %� &����'��� � � � � ! %� � � � � ! " #$ #� # #! 6 He Very few�drip�line�nuclei have�their identity card complete Drip�line�: 8 He���� � Masses,�size,�densities,�neutron�excitation,� neutron�skin low�lying spectroscopy,�Shell�structure�� ��������������������� �����������������������
Search�for�low�lying�resonances�and�study�of�neutron�excitations (p,p p,p’ ’)�probe )�probe ( Particle�spectroscopy ������������������ structure�studies�by�(p,p’)�&�(p,d)��reactions� using�GANIL/SISSI�or�SPIRAL�beams� and�MUST+CATS Elastic scattering Inelastic scattering :� sensitive�to�the� sensitive�to�the� matter rms shape of�the�density Nuclear�densities,� C.Jouanne,�VL.�et�al.,� 10,11 C(p,p’) ������ neutron�excitation PRC� �� ,��014308�(’05) rms m ( 10 C)�:� ���� ± 0.1�fm ;�rms m ( 11 C)�:� ���� ± 0.1�fm [rms m ( 12 C)�:�2.30�(3) fm] beam Weakly�bound nuclei � + ������� Unbound excited states � ��� �� low�lying resonances $ + ����� � �� MUST�:�Y.Blumenfeld et�al.,�NIM�A421,�421�(‘99)�� CATS�:�S.�Ottini et�al.,��NIM�A431,�476�(‘99). Halo,�Neutron�skin�structure ��������������������� �����������������������
�������� of�( of�(p,p p,p’ ’)�&�direct� )�&�direct�reactions reactions at at low low energy energy:� :� 8 He(p,p p,p’ ’) ) �������� 8 He( 8 He�(T 1/2 =�119ms)�I=�10 4 /s� reaction�target��CH 2 set� �up up at at GANIL GANIL set CsI 1.5�cm � ���� ��� Si(Li)�3mm � + X,�Y,�T,�E � �� ���� Si Strips 300� � m MUST � �� ���� ��������� � ��� ����� ������� � neutron�skin�? $ + Resonances � �� T 1/2 =119�ms � � ��# � PROBE�:� 8 He(p,p’) 8 He* $�� � % SPIRAL 8 He He @�15.7�A.MeV 14000�/s CH 2 [1 ary beam:� 13 C� target @�75�A.MeV] � test�of�the�validity�of�the�densities eg 6 He(p,p’) @��40.9�MeV/n�GANIL�MUST� A.�Lagoyannis et�al.,�PLB� !"� ,�27�(‘01) 2n�Halo�features 6 He����NP ���� ,�49c(‘03) Beam detector CATS2 CATS1 Collaboration�:�SPhN,�GANIL,�IPN�Orsay,� FLNR�Dubna,�Univ.�Ioannina�(Greece) ��������������������� �����������������������
Structure�of� 8 He�extracted extracted from from direct� direct�reactions reactions on�proton� on�proton�target target Structure�of� 8 He� SPIRAL 8 He�+p�@�15.7A.MeV F.�Skaza PhD SPhN F.�Skaza,�N.�Keeley,�VL� et�al., 8 He(p,d) PLB� &"' .�82�(’05) N.�Keeley et�al., PLB� &�& ,222(’07) 8 He(p,t) 6 He(0 + ) 8 He(p,p)������� CRC�calc Coupled�channel calc.:� N.�Keeley (SPhN) 8 He(p,t) 6 He(2+) Structure�of�ground�state�&�search�for�unbound�excited�states� � spectroscopy�of�light�charged�particles�p,d,t (MUST)�� � measurements�of�resonances�in�� � He�NPA�788c,�260�(’07) � angular�distributions�;�analysis�in� ����� (�� ��������)��� �* PLB� &"' .�82�(’05)�; &�& ,�222�(’07) ��������������������� �����������������������
Structure�of� 8 He�extracted�from�direct�reactions�on�proton�target Structure�of� 8 He�extracted�from�direct�reactions�on�proton�target CRC�Coupled�reaction�channel�analysis:� � He(p,d) � He�C � S�=�4.4�± 1.3� N.�Keeley (SPhN,�Inst.�A.�Soltan) [CCBAanalysis] CRC�(p,p)�(p,d)�C � S�=�3.4�± 1.3 PLB�619.�82�(’05) 8 He(p,d) 8 He(p,t) 6 He(0+) (p,t) � wave�function�of� � He% & He� [ 8 He/ 6 He(0+)]�=1�; [ 8 He/ 6 He(2+)]�=0.014 Consistent�with results from 8 He(p,t) 6 He(0 + ) quasi�free�scattering of� 8 He measured at GSI,� RIKEN�61.3�A.MeV LV�Chulkov et�al,�NP ��!' ,�43(’05) 8 He(p,t) 6 He�(2+) 1p 1/2 1p 3/2 8 He(p,t) 6 He 2+ 1s 1/2 p n CRC�calc 1p 1/2 CRC�calc 1p 3/2 1s 1/2 +��� :�A.�A.Korsheninnikov p n et�al,�PRL� '� ,�082501�(‘03) +��� :�SPIRAL�MUST�[1�2] Configuration�mixing�:� (p3/2) 4 and�(p3/2) 2 (p1/2) 2 F.�Skaza et�al.,�PRC�(’07) N.�Keeley et�al,�PLB� &�& ,�222(‘07) ��������������������� �����������������������
Conclusions Test�of�the�validity of� 8 He�gs densities using (p,p)�:� ρ � ,� ρ � neutron�skin�features�close�to�NCSM�densities COSMA�not�valid ��.� �.�/ /� � � Rms (fm) Alpha�+�4�n 8 He� Proton Neutron Matter COSMA�5�body 1.69 2.74 2.52 HF+corr Sagawa 1.95 2.67 2.51 NCSM ,����� NCSM,�Navrátil 2.00 2.59 2.46 �) ���-�( � NCSM�(No�Core�Shell�Model)� ( V3eff�4hw,�13MeV� ) Validation�of�no�core�shell�model� COSMA: calculations�(NCSM)�for�gs Alpha+4n (p,p’)�mainly�sensitive�to�the�neutron�excitation�;� Transition�densities�2+� � 0+ :�NCSM�calc.�overestimate�the�p�&�n�excitations Test�of�transition�densities ;�Analysis in�progress �0����.� �0��� �.�/ /�� �� Coupling Coupling with with the�( the�(p,t p,t) ) NEUTRON� NEUTRON �SKIN�THICKNESS:�~�0.6�+/ SKIN�THICKNESS:�~�0.6�+/� � 0.05� 0.05�fm fm ��������������������� �����������������������
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