RT Journal Article T1 The boundary of the N=90 shape phase transition: 148Ce A1 Fraile Prieto, Luis Mario A1 otros, ... AB The even-even N=90 isotones with Z=60-66 are known to undergo a first order phase transition. Such a phase transition in atomic nuclei is characterized by a sudden change of the shape of the nucleus due to changes in the location of the potential minimum. In these proceedings we report a measurement of the B(4/2 )ratio of Ce-148, which will probe the location of the low-Z boundary of the N=90 phase transitional region. The measured B(4/2 )value is compared to the prediction from the X(5) symmetry within the interacting boson model at the critical point between the geometrical limits of vibrators and rigid/axial rotors. The EXILL&FATIMA campaign took place at the high-flux reactor of the Institut Laue Langevin, Grenoble, were U-235 and Pu-241 fission fragments were measured by a hybrid spectrometer consisting of high-resolution HPGe and fast LaBr3 (Ce)-scintillator detectors. The fast LaBr3 (Ce) detectors in combination with the generalized centroid difference method allowed lifetime measurements in the picosecond region. Furthermore, this kind of analysis can serve as preparation for the FATIMA experiments at FAIR. PB IOP Publishing Ltd SN 1742-6588 YR 2018 FD 2018 LK https://hdl.handle.net/20.500.14352/18735 UL https://hdl.handle.net/20.500.14352/18735 LA eng NO Artículo firmado por 34 autores. International School on Nuclear Physics, Neutron Physics and Applications (22nd. 2017. Varna, Bulgaria). This work was supported by the cooperation between TU Darmstadt and the GSI Helmholtz Center for Heavy Ion Research and by HGS-HIRe, by US DOE under No. DE-FG02-91ER-40609, by STFC (UK) under No. ST/L005743/1 and ST/G000751/1, by Istanbul University Scientific Research Project No. 54135, by DFG under No. KR 1796/2-1 and KR 1796/2-2 and by BMBF under No. 05P12RDNUP 05P15RDFN1, 05P15PKFNA and 05P12PKNU. NO TU Darmstadt NO GSI Helmholtz Center for Heavy Ion Research NO HGS-HIRe NO US DOE NO STFC (UK) NO Istanbul University Scientific Research Project NO DFG NO BMBF DS Docta Complutense RD 25 dic 2025