Lifetimes of excited nuclear states were determined in 59Ni and 57Fe utilizing the recoil distance Doppler-shift technique. The results are based on the fusion-evaporation reactions 51V(12C, pn alpha) 57Fe and 51V(12C,p3n)59Ni measured at the FN Tandem accelerator in Cologne. Reduced transition strengths were deduced from the lifetime values and compared to shell-model calculations employing the GXPF1A interaction along the N = 31 isotonic chain and for several Z = 28 even-odd Ni isotopes. Existing large discrepancies between previous experimental E2 strength values and the corresponding GXPF1A values in 59Ni were resolved by the new experimental results. The shell closure for the Z = 28 isotope 59Ni, indicated by a drop in the B(E 2; 9/2-1 -> 5/2-1 ) value, is clearly observed, in contrast to evaluated data. Despite the good agreement between experiment and theory for most B(E2) values, considerable deviations remain for the new experimental B(M1) values and results from GXPF1A calculations.

Excited states in 57Mn are populated using the 55Mn(18O, 16O) 57Mn two-neutron transfer reaction at the FN tandem accelerator in Cologne. Lifetimes of excited nuclear states in 57Mn were determined utilizing the Doppler-shift attenuation method. A comparison between experiment and shell-model theory was made for excitation energies and reduced transition strengths along the odd-Z isotopes Sc, V, Mn, and Co. The new results on transition strengths in 57Mn are described well by the standard interactions GXPF1A and KB3G. The development along the N = 32 isotones for these odd-Z nuclei and discrepancies between experiment and theory are discussed.

Lifetimes and reduced transition probabilities were determined in the ground-state band in Pd-104 up to the 12(+) state employing the recoil distance Doppler-shift method. Excited states were populated via the fusion-evaporation reaction Zr-96(C-12, 4n)Pd-104 at 55 MeV. The B(E2; 2(i)(+) -> O-g+s.(+)) value deviates from previous evaluated values obtained by Coulomb excitation and electron scattering. The transition strengths for higher-lying states were obtained for the first time, closing a gap in the medium-mass Pd isotope chain. Large-scale shell-model calculations were performed employing the SR88MHJM Hamiltonian along the isotope chain Pd96-106 for even-even nuclei and for high-spin states up to 26(+) in Pd-104.

Excited states in Cr-55 have been populated via the fusion-evaporation reaction Ca-48(B-11, p3n) Cr-55 at a beam energy of 32 MeV. The Cologne plunger device surrounded by a gamma-ray detector array was employed to determine lifetimes with the recoil-distance Doppler-shift method. gamma rays were observed by one Ge EUROBALL cluster detector and five HPGe detectors. gamma gamma-coincidence data were analyzed with help from the differential decay-curve method, and precise lifetimes for the first excited states were extracted from the 5/2(-) -> 3/2(-) and the 9/2(-) -> 5/2(-) transitions. Reduced transition strengths B(sigma lambda) were determined and compared to shell-model calculations employing four interactions KB3G, FPD6, GXPF1A, and GXPF1Br. The calculations were also performed for the N = 31 isotonic chain from Ti-53 to Zn-61. Inspection of the wave functions as well as particle-plus-rotor model calculations allow for a detailed understanding of the excited states and the reduced transition strength in Cr-55.

Lifetime measurements of excited states in doubly-magic 56Ni have been performed exploiting the Doppler-shift attenuation method in order to determine reduced transition probabilities. For the 41+ and 61+ states, the deduced B(E2) values are compared with results from shell-model calculations employing the GXPF1A and the modern PFSDG-U interactions. In addition, valence ab-initio calculations were performed using a novel realistic Hamiltonian derived from chiral perturbation theory including three-body potential contributions and are confronted with the experimental findings. The new results show maximum E2 strength in comparison with known values along the N=28 chain of isotones. The results corroborate the high collectivity for the double shell closure at N=Z=28 which was anticipated from the large B(E2;21+→0g.s.+) value despite the considerable increase of its excitation energy as compared to neighboring semi-magic nuclei. Based on similarities in the shell structures of the self-conjugate doubly-magic nuclei 56Ni and 100Sn, the new values could be an indication for an expected comparable collective behavior of the 61+ state in 100Sn.

Lifetimes of excited nuclear states were determined in Ti-44 using the recoil distance Doppler-shift technique and the Doppler-shift attenuation method. Results from the K-pi = 3(-) band confirm isospin-symmetry breaking for the 3(1)(-) -> 2(1)(+) E1 transition. The lifetime of the 4(1)(-) state differs considerably from the previously known value. Good agreement is found for the 4(1)(+) and 6(1)(+) level lifetimes with respect to previous values. The experimental values are compared with large-scale shell-model calculations employing established interactions in the 0f1p shell, as well as a modern effective Hamiltonian including multiparticle multihole cross-shell configurations. Extended configuration spaces of this shell-model calculation allow for a detailed comparison with newly determined negative-parity states.

The transitional nuclei Ba-134 and Ba-133 are investigated after multinucleon transfer employing the high-resolution Advanced GAmma Tracking Array coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and after fusion-evaporation reaction at the FN tandem accelerator of the University of Cologne, Germany. The J(pi) = 19/2(+) state at 1942 keV in Ba-133 is identified as an isomer with a half-life of 66.6(20) ns corresponding to a B(E1) value of 7.7(4) x 10(-6) e(2) fm(2) for the J(pi) = 19/2(+) to J(pi) = 19/2(-) transition. The level scheme of Ba-134 above the J(pi) = 10(+) isomer is extended to approximately 6 MeV. A pronounced backbending is observed at h omega = 0.38 MeV along the positive-parity yrast band. The results are compared to the high-spin systematics of the Z = 56 isotopes. Large-scale shell-model calculations employing the GCN50:82, SN100PN, SNV, PQM130, Realistic SM, and EPQQM interactions reproduce the experimental findings and elucidate the structure of the high-spin states. The shell-model calculations employing the GCN50:82 and PQM130 interactions reproduce alignment properties and provide detailed insight into the microscopic origin of this phenomenon in transitional Ba-134.

L. Kaya,1, a A. Vogt,1 P. Reiter,1 M. Siciliano,2, 3 N. Shimizu,4 Y. Utsuno,4, 5 H.-K. Wang,6 A. Gargano,7 2 L. Coraggio,7 N. Itaco,7, 8 K. Arnswald,1 D. Bazzacco,9 B. Birkenbach,1 A. Blazhev,1 A. Bracco,10 3 B. Bruyneel,11 L. Corradi,3 F. C. L. Crespi,10 G. de Angelis,3 M. Droste,1 J. Eberth,1 E. Farnea,9, b 4 E. Fioretto,3 C. Fransen,1 A. Gadea,12 A. Giaz,10 A. Görgen,13, 14, 15 A. Gottardo,3 K. Hadyńska-Klęk,3 5 H. Hess,1 R. Hirsch,1 P. R. John,16 J. Jolie,1 A. Jungclaus,17 V. Karayonchev,1 L. Kornwebel,1 W. 6 Korten,14 S. Leoni,10 L. Lewandowski,1 S. Lunardi,2, 9 R. Menegazzo,9 D. Mengoni,2, 9 C. Michelagnoli,18 7 T. Mijatović,19 G. Montagnoli,2, 9 D. Montanari,20 C. Müller-Gatermann,1 D. Napoli,3 Zs. Podolyák,21 G. 8 Pollarolo,22 F. Recchia,2, 9 J.-M. Régis,1 N. Saed-Samii,1 E. Şahin,23 F. Scarlassara,2, 9 K. Schomacker,1 9 M. Seidlitz,1 B. Siebeck,1 P.-A. Söderström,24 A. M. Stefanini,3 O. Stezowski,25 S. Szilner,19 B. Szpak,26 10 E. Teruya,27 C. Ur,9 J. J. Valiente-Dobón,3 K. Wolf,1 K. Yanase,27 N. Yoshinaga,27 and K. O. Zell1 11

L. Kaya,1,* A. Vogt,1 P. Reiter,1 M. Siciliano,2,3,4 N. Shimizu,5 Y. Utsuno,5,6 H.-K. Wang,7 A. Gargano,8 L. Coraggio,8 N. Itaco,8,9 K. Arnswald,1 D. Bazzacco,10 B. Birkenbach,1 A. Blazhev,1 A. Bracco,11 B. Bruyneel,4 L. Corradi,3 F. C. L. Crespi,11 G. de Angelis,3 M. Droste,1 J. Eberth,1 A. Esmaylzadeh,1 E. Farnea,10,† E. Fioretto,3 C. Fransen,1 A. Gadea,12 A. Giaz,11 A. Görgen,13,4 A. Gottardo,3 K. Hadyńska-Klęk,3 H. Hess,1 R. Hirsch,1 P. R. John,14 J. Jolie,1 A. Jungclaus,15 V. Karayonchev,1 L. Kornwebel,1 W. Korten,4 S. Leoni,11 L. Lewandowski,1 S. Lunardi,2,10 R. Menegazzo,10 D. Mengoni,2,10 C. Michelagnoli,16 T. Mijatović,17 G. Montagnoli,2,10 D. Montanari,2,10 C. Müller-Gatermann,1 D. Napoli,3 Zs. Podolyák,18 G. Pollarolo,19 F. Recchia,2,10 J.-M. Régis,1 N. Saed-Samii,1 E. Şahin,13 F. Scarlassara,2,10 K. Schomacker,1 M. Seidlitz,1 B. Siebeck,1 P.-A. Söderström,20 A. M. Stefanini,3 O. Stezowski,21 S. Szilner,17 B. Szpak,22 E. Teruya,23 C. Ur,10 J. J. Valiente-Dobón,3 K. Wolf,1 K. Yanase,23 N. Yoshinaga,23 and K. O. Zell1 1Institut für Kernphysik, Universität zu Köln, D-50937 Köln, Germany 2Dipartimento di Fisica e Astronomia, Università di Padova, I-35131 Padova, Italy 3Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy 4Institut de Recherche sur les lois Fondamentales de l’Univers – IRFU, CEA/DSM,

The high-spin structures of Ba-136 and Ba-137 are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Ba-136 is populated in a Xe-136 + U-238 MNT reaction employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and in two Be-9 + Te-130 fusion-evaporation reactions using the High-efficiency Observatory for gamma-Ray Unique Spectroscopy (HORUS) at the FN tandem accelerator of the University of Cologne, Germany. Furthermore, both isotopes are populated in an elusive reaction channel in the B-11 + Te-130 fusion-evaporation reaction utilizing the HORUS gamma-ray array. The level scheme above the J(pi) = 10(+) isomer in Ba-136 is revised and extended up to an excitation energy of approximately 5.5 MeV. From the results of angular-correlation measurements, the E-x = 3707- and E-x = 4920-keV states are identified as the bandheads of positive- and negative-parity cascades. While the high-spin regimes of both Te-132 and Xe-134 are characterized by high-energy 12(+) -> 10(+) transitions, the Ba-136 E2 ground-state band is interrupted by negative-parity states only a few hundred keV above the J(pi) = 10(+) isomer. Furthermore, spins are established for several hitherto unassigned high-spin states in Ba-137. The new results close a gap along the high-spin structure of N < 82 Ba isotopes. Experimental results are compared to large-scale shell-model calculations employing the GCN50:82, Realistic SM, PQM130, and SN100PN interactions. The calculations suggest that the bandheads of the positive-parity bands in both isotopes are predominantly of proton character.

L. Kaya,1,* A. Vogt,1 P. Reiter,1 C. Müller-Gatermann,1 A. Gargano,2 L. Coraggio,2 N. Itaco,2,3 A. Blazhev,1 K. Arnswald,1 D. Bazzacco,4 B. Birkenbach,1 A. Bracco,5 B. Bruyneel,6 L. Corradi,7 F. C. L. Crespi,5 G. de Angelis,7 M. Droste,1 J. Eberth,1 E. Farnea,4,† E. Fioretto,7 C. Fransen,1 A. Gadea,8 A. Giaz,5 A. Görgen,9,10,11 A. Gottardo,7 K. Hadyńska-Klęk,7 H. Hess,1 R. Hetzenegger,1 R. Hirsch,1 P. R. John,12 J. Jolie,1 A. Jungclaus,13 W. Korten,10 S. Leoni,5 L. Lewandowski,1 S. Lunardi,14,4 R. Menegazzo,4 D. Mengoni,14,4 C. Michelagnoli,15 T. Mijatović,16 G. Montagnoli,14,4 D. Montanari,17 D. Napoli,7 Zs. Podolyák,18 G. Pollarolo,19 F. Recchia,14,4 D. Rosiak,1 N. Saed-Samii,1 E. Şahin,9 M. Siciliano,14,7 F. Scarlassara,14,4 M. Seidlitz,1 P.-A. Söderström,20 A. M. Stefanini,7 O. Stezowski,21 S. Szilner,16 B. Szpak,22 C. Ur,4 J. J. Valiente-Dobón,7 M. Weinert,1 K. Wolf,1 and K. O. Zell1 1Institut für Kernphysik, Universität zu Köln, D-50937 Köln, Germany 2Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, I-80126 Napoli, Italy 3Dipartimento di Matematica e Fisica, Università degli Studi della Campania “Luigi Vanvitelli”,

L. Kaya,1, a A. Vogt,1 P. Reiter,1 C. Müller-Gatermann,1 M. Siciliano,2, 3 L. Coraggio,4 N. Itaco,4, 5 A. Gargano,4 K. 2 Arnswald,1 D. Bazzacco,6 B. Birkenbach,1 A. Blazhev,1 A. Bracco,7 B. Bruyneel,8 L. Corradi,3 F. C. L. Crespi,7 G. 3 de Angelis,3 M. Droste,1 J. Eberth,1 E. Farnea,6, b E. Fioretto,3 C. Fransen,1 A. Gadea,9 A. Giaz,7 A. Görgen,10, 11, 12 4 A. Gottardo,3 K. Hadyńska-Klęk,3 H. Hess,1 R. Hetzenegger,1 R. Hirsch,1 P. R. John,13 J. Jolie,1 A. Jungclaus,14 5 W. Korten,11 S. Leoni,7 L. Lewandowski,1 S. Lunardi,2, 6 R. Menegazzo,6 D. Mengoni,15, 2, 6 C. Michelagnoli,16 T. 6 Mijatović,17 G. Montagnoli,2, 6 D. Montanari,18 D. Napoli,3 Zs. Podolyák,19 G. Pollarolo,20 F. Recchia,2, 6 D. 7 Rosiak,1 N. Saed-Samii,1 E. Şahin,21 F. Scarlassara,2, 6 M. Seidlitz,1 P.-A. Söderström,13 A. M. Stefanini,3 O. 8 Stezowski,22 S. Szilner,17 B. Szpak,23 C. Ur,6 J. J. Valiente-Dobón,3 M. Weinert,1 K. Wolf,1 and K. O. Zell1 9

L. Kaya,1, a A. Vogt,1 P. Reiter,1 C. Müller-Gatermann,1 A. Gargano,2 L. Coraggio,2 N. Itaco,2, 3 A. 2 Blazhev,1 K. Arnswald,1 D. Bazzacco,4 B. Birkenbach,1 A. Bracco,5 B. Bruyneel,6 L. Corradi,7 F. C. L. 3 Crespi,5 G. de Angelis,7 M. Droste,1 J. Eberth,1 E. Farnea,4, b E. Fioretto,7 C. Fransen,1 A. Gadea,8 A. 4 Giaz,5 A. Görgen,9, 10, 11 A. Gottardo,7 K. Hadyńska-Klęk,7 H. Hess,1 R. Hetzenegger,1 R. Hirsch,1 P. 5 R. John,12 J. Jolie,1 A. Jungclaus,13 W. Korten,10 S. Leoni,5 L. Lewandowski,1 S. Lunardi,14, 4 R. 6 Menegazzo,4 D. Mengoni,14, 4 C. Michelagnoli,15 T. Mijatović,16 G. Montagnoli,14, 4 D. Montanari,17 D. 7 Napoli,7 Zs. Podolyák,18 G. Pollarolo,19 F. Recchia,14, 4 D. Rosiak,1 N. Saed-Samii,1 E. Şahin,20 M. 8 Siciliano,14, 7 F. Scarlassara,14, 4 M. Seidlitz,1 P.-A. Söderström,21 A. M. Stefanini,7 O. Stezowski,22 9 S. Szilner,16 B. Szpak,23 C. Ur,4 J. J. Valiente-Dobón,7 M. Weinert,1 K. Wolf,1 and K. O. Zell1 10

Detailed information on isomeric states in $A\ensuremath{\approx}135$ nuclei is exploited to benchmark shell-model calculations in the region northwest of doubly magic nucleus $^{132}\mathrm{Sn}$. The $N=79$ isotones $^{133}\mathrm{Xe}$ and $^{135}\mathrm{Ba}$ are studied after multinucleon transfer in the $^{136}\mathrm{Xe}+^{208}\mathrm{Pb}$ reaction employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy and in a pulsed-beam experiment at the FN tandem accelerator of the University of Cologne, Germany utilizing a $^{9}\mathrm{Be}+^{130}\mathrm{Te}$ fusion-evaporation reaction at a beam energy of 40 MeV. Isomeric states are identified via delayed $\ensuremath{\gamma}$-ray spectroscopy. Hitherto tentative excitation energy, spin, and parity assignments of the 2107-keV ${J}^{\ensuremath{\pi}}=23/{2}^{+}$ isomer in $^{133}\mathrm{Xe}$ are confirmed and a half-life of ${T}_{1/2}=8.64(13)$ ms is measured. The 2388-keV state in $^{135}\mathrm{Ba}$ is identified as a ${J}^{\ensuremath{\pi}}=23/{2}^{+}$ isomer with a half-life of 1.06(4) ms. The new results show a smooth onset of isomeric ${J}^{\ensuremath{\pi}}=23/{2}^{+}$ states along the $N=79$ isotones and close a gap in the high-spin systematics towards the recently investigated ${J}^{\ensuremath{\pi}}=23/{2}^{+}$ isomer in $^{139}\mathrm{Nd}$. The resulting systematics of $M2$ reduced transition probabilities is discussed within the framework of the nuclear shell model. Latest large-scale shell-model calculations employing the SN100PN, GCN50:82, SN100-KTH, and a realistic effective interaction reproduce the experimental findings generally well and give insight into the structure of the isomers.

L. Kaya,1, a A. Vogt,1 P. Reiter,1 C. Müller-Gatermann,1 A. Gargano,2 L. Coraggio,2 N. Itaco,2, 3 A. 2 Blazhev,1 K. Arnswald,1 D. Bazzacco,4 B. Birkenbach,1 A. Bracco,5 B. Bruyneel,6 L. Corradi,7 F. C. L. 3 Crespi,5 G. de Angelis,7 M. Droste,1 J. Eberth,1 E. Farnea,4, b E. Fioretto,7 C. Fransen,1 A. Gadea,8 A. 4 Giaz,5 A. Görgen,9, 10, 11 A. Gottardo,7 K. Hadyńska-Klęk,7 H. Hess,1 R. Hetzenegger,1 R. Hirsch,1 P. 5 R. John,12 J. Jolie,1 A. Jungclaus,13 W. Korten,10 S. Leoni,5 L. Lewandowski,1 S. Lunardi,14, 4 R. 6 Menegazzo,4 D. Mengoni,14, 4 C. Michelagnoli,15 T. Mijatović,16 G. Montagnoli,14, 4 D. Montanari,17 D. 7 Napoli,7 Zs. Podolyák,18 G. Pollarolo,19 F. Recchia,14, 4 D. Rosiak,1 N. Saed-Samii,1 E. Şahin,20 M. 8 Siciliano,14, 7 F. Scarlassara,14, 4 M. Seidlitz,1 P.-A. Söderström,21 A. M. Stefanini,7 O. Stezowski,22 9 S. Szilner,16 B. Szpak,23 C. Ur,4 J. J. Valiente-Dobón,7 M. Weinert,1 K. Wolf,1 and K. O. Zell1 10

Detailed information on isomeric states in A approximate to 135 nuclei is exploited to shell-model calculations in the region northwest of doubly magic nucleus Sn-132. The N = 79 isotones Xe-133 and Ba-135 are studied after multinucleon transfer in the Xe-136 + Pb-208 reaction employing the high-resolution Advanced GAmma Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy and in a pulsed-beam experiment at the FN tandem accelerator of the University of Cologne Germany utilizing a Be-9 + Te-130 fusion-evaporation reaction at a beam energy of 40 MeV. Isomeric states are identified via delayed gamma-ray spectroscopy. Hitherto tentative excitation energy spin and parity assignments of the 2017-keV J(pi) = 23/2(+) isomer in Xe-133 are confirmed and a half-life of T-1/2 = 8.64(13) ms is measured. The 2388-keV state in Ba-135. is identified as a J(pi) = 23/2(+) isomer with a half-life of 1.06(4) ms. The new results show a smooth onset of isomeric J(pi) = 23/2(+) states along the N = 79 isotones and close a gap in the high-spin systematics towards the recently investigated J(pi) = 23/2(+) isomer in Nd-139. The resulting systematics of M2 reduced transition probabilities is discussed within the of the nuclear shell model. Latest large-scale shell-model calculations employing the SN100PN, GCN50:82, SN100-KTH and a realistic effective interaction reproduce the experimental findings generally well and give insight into the structure of the isomers.

Detailed information on isomeric states in A ≈ 135 nuclei is exploited to benchmark shell-model calculations in the region northwest of doubly-magic nucleus 132Sn. The N = 79 isotones 133Xe and 135Ba are studied after multinucleon transfer (MNT) in the 136Xe + 208Pb reaction employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy and in a pulsed-beam experiment at the FN tandem accelerator of the University of Cologne, Germany utilizing a 9Be+130Te fusion-evaporation reaction at a beam energy of 40 MeV. Isomeric states are identified via delayed γ-ray spectroscopy. Hitherto tentative excitation energy, spin, and parity assignments of the 2107-keV Jπ = 23/2+ isomer in 133Xe are confirmed and a half-life of T1/2 = 8.64(13) ms is measured. The 2388-keV state in 135Ba is identified as a Jπ = 23/2+ isomer with a half-life of 1.06(4) ms. The new results show a smooth onset of isomeric Jπ = 23/2+ states along the N = 79 isotones and close a gap in the high-spin systematics towards the recently investigated Jπ = 23/2+ isomer in 139Nd. The resulting systematics of M2 reduced transition probabilities is discussed within the framework of the nuclear shell model. Latest large-scale shell-model calculations employing the SN100PN, GCN50:82, SN100-KTH, and a realistic effective interaction reproduce the experimental findings generally well and give insight into the structure of the isomers.