1−and2+discrete states inZr90populated via the

Multitude of2+discrete states inSn124observed via the(O17Pellegri1, Bracco2, Tsoneva3 et al. 2015Phys. Rev. CSelf Cite272180View full textAdd to dashboardCite

“…Among the most interesting findings of nuclear structure physics there are those concerning the nuclear dipole response at energies below and close to the particle emission threshold in stable and unstable nuclei with charge asymmetry N/Z > 1 where a new excitation mode called the pygmy dipole resonance (PDR) has been observed [1]. That mode was intensively investigated in many experimental and theoretical studies in which unknown aspects on the isospin dynamics of the nucleus have been revealed (see [1] and [2] for reviews and, e.g., the recent experiments [3][4][5]). Typically, the PDR appears as an additional dipole strength situated on top of the low-energy tail of the giant dipole resonance (GDR) [6].…”

Toroidal, compressive, and E1 properties of low-energy dipole modes in Be10

“…[1][2][3][4] and references therein). Remarkable progress has been made in these years in experimentally studying isospin characters of low-energy dipole excitations for various nuclei, in particular, neutron-rich nuclei [4][5][6][7][8][9]. For stable nuclei, familiar dipole excitations in high-energy region known to be giant dipole resonances (GDRs) have been systematically observed in various nuclei by means of photonuclear reactions and α (or 6 Li) inelastic scatterings, which can probe isovector (IV) and isoscalar (IS) dipole excitations, respectively [10][11][12][13][14].…”

Nature of low-lying electric dipole resonance excitations inGe74

“…The PDR has been interpreted as an exotic mode of excitation due to the motion of a weakly bound neutron excess against an almost inert proton-neutron core [1][2][3], although single particlehole excitations are also considered [4,5]. One major reason for the renewed interest in the PDR is the possibility of carrying out high-resolution measurements on these low-lying dipole excitations using heavy ion [6,7], proton [8,9], and α inelastic scattering experiments [10,11]. An experimental technique, combining particle and γray detection techniques, to study the response of dipole excitations to isoscalar probes was pioneered by Poelhekken et al [12] and applied in several studies since [6,7,10,11,[13][14][15][16][17].…”

“…One major reason for the renewed interest in the PDR is the possibility of carrying out high-resolution measurements on these low-lying dipole excitations using heavy ion [6,7], proton [8,9], and α inelastic scattering experiments [10,11]. An experimental technique, combining particle and γray detection techniques, to study the response of dipole excitations to isoscalar probes was pioneered by Poelhekken et al [12] and applied in several studies since [6,7,10,11,[13][14][15][16][17]. These experiments provide complementary information to those obtained from (γ, γ ′ ) experiments which investigate the isovector nature of the excitations [18][19][20][21][22][23][24].…”

“…Incidentally, scattering experiments with isocalar probes for the study of the PDR have so far been limited to only certain regions of the nuclear chart and carried out mainly on nuclei with large neutron-to-proton ratios [6,10,13,14,17]. Information on how the results from scattering reactions compare to those of (γ, γ ′ ) experiments in nuclei closer to N/Z =1 are also becoming available [7,12,15,16]. Since most of the incident isoscalar probes are sensitive to the surface of the nucleus, the information gathered advances our understanding of the evolution of the PDR with changing N/Z.…”