Splitting of the Pygmy Dipole Resonance

Endres J; Butler P; Harakeh M.N.; Harissopulos S; Herzberg R.-D.; Kruecken R.; Lagoyannis A; Litvinova E.; Pietralla N.; Tonomarev V.Yu.; Lucia Popescu; Ring P; Savran D.; Scheck M.; Sonnabend K.; Stoica V.I.; Woertche H.J.; Zilges A.; Dieter Pauwels

Splitting of the Pygmy Dipole Resonance

Endres J, Butler P, Harakeh M.N., Harissopulos S, Herzberg R.-D., Kruecken R., Lagoyannis A, Litvinova E., Pietralla N., Tonomarev V.Yu., Lucia Popescu, Ring P, Savran D., Scheck M., Sonnabend K., Stoica V.I., Woertche H.J., Zilges A., Dieter Pauwels

Research output › peer-review

Abstract

In recent years investigations have been made to study the electric Pygmy Dipole Resonance (PDR) systematically, mainly in semi-magic nuclei. For this purpose the well understood high resolution (γ ,γ ') photon scattering method is used. In complementary (α,α'γ ) coincidence experiments at Eα = 136 MeV a similar γ -energy resolution and a high selectivity to E1 transitions can be obtained at the Big-Bite Spectrometer (BBS) at KVI, Groningen. In comparison to the (γ ,γ') method a structural splitting of the PDR is observed in the N=82 nuclei 138Ba and 140Ce and in the Z=50 nucleus 124Sn. The low energy part is excited in (γ ,γ') as well as in (α,α'γ ) while the high energy part is observed in (γ ,γ') only. The experimental results together with theoretical QPM and RQTBA calculations on 124Sn which are able to reproduce the splitting of the PDR qualitatively are presented. The low-lying group of 1− states seem to represent the more isoscalar neutron-skin oscillation of the PDR while the energetically higher-lying states seemingly belong to the transitional region between the PDR and the isovector Giant Dipole Resonance (IVGDR).

Original language	English
Title of host publication	Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3
Place of Publication	United States
Pages	260-264
Volume	1
State	Published - 28 Oct 2011
Event	Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3 - Rhodes Duration: 23 Aug 2010 → 27 Aug 2010

Publication series

Name	AIP Conference Proceedings
Number	1377

Conference

Conference	Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3
Country/Territory	Greece
City	Rhodes
Period	2010-08-23 → 2010-08-27

Cite this

J, Endres ; P, Butler ; M.N., Harakeh ; S, Harissopulos ; R.-D., Herzberg ; R., Kruecken ; A, Lagoyannis ; E., Litvinova ; N., Pietralla ; V.Yu., Tonomarev ; Popescu, Lucia ; P, Ring ; D., Savran ; M., Scheck ; K., Sonnabend ; V.I., Stoica ; H.J., Woertche ; A., Zilges ; Pauwels, Dieter. / Splitting of the Pygmy Dipole Resonance. Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3. Vol. 1 United States, 2011. pp. 260-264 (AIP Conference Proceedings; 1377).

@inproceedings{df8305cf1fd34957913a0b4978dd1fe7,

title = "Splitting of the Pygmy Dipole Resonance",

abstract = "In recent years investigations have been made to study the electric Pygmy Dipole Resonance (PDR) systematically, mainly in semi-magic nuclei. For this purpose the well understood high resolution (γ ,γ ') photon scattering method is used. In complementary (α,α'γ ) coincidence experiments at Eα = 136 MeV a similar γ -energy resolution and a high selectivity to E1 transitions can be obtained at the Big-Bite Spectrometer (BBS) at KVI, Groningen. In comparison to the (γ ,γ') method a structural splitting of the PDR is observed in the N=82 nuclei 138Ba and 140Ce and in the Z=50 nucleus 124Sn. The low energy part is excited in (γ ,γ') as well as in (α,α'γ ) while the high energy part is observed in (γ ,γ') only. The experimental results together with theoretical QPM and RQTBA calculations on 124Sn which are able to reproduce the splitting of the PDR qualitatively are presented. The low-lying group of 1− states seem to represent the more isoscalar neutron-skin oscillation of the PDR while the energetically higher-lying states seemingly belong to the transitional region between the PDR and the isovector Giant Dipole Resonance (IVGDR).",

keywords = "PDR, QPM, RQTBA, nuclear reactions, 124Sn(α, α'γ )",

author = "Endres J and Butler P and Harakeh M.N. and Harissopulos S and Herzberg R.-D. and Kruecken R. and Lagoyannis A and Litvinova E. and Pietralla N. and Tonomarev V.Yu. and Lucia Popescu and Ring P and Savran D. and Scheck M. and Sonnabend K. and Stoica V.I. and Woertche H.J. and Zilges A. and Dieter Pauwels",

note = "Score = 3; Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3 ; Conference date: 23-08-2010 Through 27-08-2010",

year = "2011",

month = oct,

day = "28",

language = "English",

isbn = "978-0-7354-0937-8",

volume = "1",

series = "AIP Conference Proceedings",

number = "1377",

pages = "260--264",

booktitle = "Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3",

}

J, E, P, B, M.N., H, S, H, R.-D., H, R., K, A, L, E., L, N., P, V.Yu., T, Popescu, L, P, R, D., S, M., S, K., S, V.I., S, H.J., W, A., Z & Pauwels, D 2011, Splitting of the Pygmy Dipole Resonance. in Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3. vol. 1, AIP Conference Proceedings, no. 1377, United States, pp. 260-264, Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3, Rhodes, Greece, 2010-08-23.

Splitting of the Pygmy Dipole Resonance. / J, Endres; P, Butler; M.N., Harakeh; S, Harissopulos; R.-D., Herzberg; R., Kruecken; A, Lagoyannis; E., Litvinova; N., Pietralla; V.Yu., Tonomarev; Popescu, Lucia; P, Ring; D., Savran; M., Scheck; K., Sonnabend; V.I., Stoica; H.J., Woertche; A., Zilges; Pauwels, Dieter (null).

Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3. Vol. 1 United States, 2011. p. 260-264 (AIP Conference Proceedings; No. 1377).

Research output › peer-review

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AU - P, Butler

AU - M.N., Harakeh

AU - S, Harissopulos

AU - R.-D., Herzberg

AU - R., Kruecken

AU - A, Lagoyannis

AU - E., Litvinova

AU - N., Pietralla

AU - V.Yu., Tonomarev

AU - Popescu, Lucia

AU - P, Ring

AU - D., Savran

AU - M., Scheck

AU - K., Sonnabend

AU - V.I., Stoica

AU - H.J., Woertche

AU - A., Zilges

A2 - Pauwels, Dieter

N1 - Score = 3

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N2 - In recent years investigations have been made to study the electric Pygmy Dipole Resonance (PDR) systematically, mainly in semi-magic nuclei. For this purpose the well understood high resolution (γ ,γ ') photon scattering method is used. In complementary (α,α'γ ) coincidence experiments at Eα = 136 MeV a similar γ -energy resolution and a high selectivity to E1 transitions can be obtained at the Big-Bite Spectrometer (BBS) at KVI, Groningen. In comparison to the (γ ,γ') method a structural splitting of the PDR is observed in the N=82 nuclei 138Ba and 140Ce and in the Z=50 nucleus 124Sn. The low energy part is excited in (γ ,γ') as well as in (α,α'γ ) while the high energy part is observed in (γ ,γ') only. The experimental results together with theoretical QPM and RQTBA calculations on 124Sn which are able to reproduce the splitting of the PDR qualitatively are presented. The low-lying group of 1− states seem to represent the more isoscalar neutron-skin oscillation of the PDR while the energetically higher-lying states seemingly belong to the transitional region between the PDR and the isovector Giant Dipole Resonance (IVGDR).

AB - In recent years investigations have been made to study the electric Pygmy Dipole Resonance (PDR) systematically, mainly in semi-magic nuclei. For this purpose the well understood high resolution (γ ,γ ') photon scattering method is used. In complementary (α,α'γ ) coincidence experiments at Eα = 136 MeV a similar γ -energy resolution and a high selectivity to E1 transitions can be obtained at the Big-Bite Spectrometer (BBS) at KVI, Groningen. In comparison to the (γ ,γ') method a structural splitting of the PDR is observed in the N=82 nuclei 138Ba and 140Ce and in the Z=50 nucleus 124Sn. The low energy part is excited in (γ ,γ') as well as in (α,α'γ ) while the high energy part is observed in (γ ,γ') only. The experimental results together with theoretical QPM and RQTBA calculations on 124Sn which are able to reproduce the splitting of the PDR qualitatively are presented. The low-lying group of 1− states seem to represent the more isoscalar neutron-skin oscillation of the PDR while the energetically higher-lying states seemingly belong to the transitional region between the PDR and the isovector Giant Dipole Resonance (IVGDR).

KW - PDR

KW - QPM

KW - RQTBA

KW - nuclear reactions

KW - 124Sn(α

KW - α'γ )

UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_116460

UR - http://knowledgecentre.sckcen.be/so2/bibref/8398

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SN - 978-0-7354-0937-8

VL - 1

T3 - AIP Conference Proceedings

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EP - 264

BT - Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3

CY - United States

T2 - Frontiers in Nuclear Structure, Astrophysics, and Reactions: FINUSTAR 3

Y2 - 23 August 2010 through 27 August 2010

ER -