Measurement of giant dipole resonance width at low temperature: A new experimental perspective

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• 作者：S. Mukhopadhyay^a ; Deepak Pandit^a ; Surajit Pal^a ; Srijit Bhattacharya^b ; A. De^c ; S. Bhattacharya^a ; C. Bhattacharya^a ; K. Banerjee^a ; S. Kundu^a ; T.K. Rana^a ; G. Mukherjee^a ; R. Pandey^a ; M. Gohil^a ; H. Pai^a ; J.K. Meena^a ; S.R. Banerjee^a ; ^{srb@vecc.gov.in}
• 关键词：Low temperature GDR width ; Adiabatic thermal shape fluctuation model ; BaF2 detectors
• 刊名：Physics Letters B
• 出版年：2012
• 出版时间：13 March 2012
• 年：2012
• 卷：709
• 期：1-2
• 页码：9-13
• 全文大小：253 K

文摘

The systematic evolution of the giant dipole resonance (GDR) width in the temperature region of has been measured experimentally for ¹¹⁹Sb using alpha induced fusion reaction and employing the LAMBDA high energy photon spectrometer. The temperatures have been precisely determined by simultaneously extracting the vital level density parameter from the neutron evaporation spectrum and the angular momentum from gamma multiplicity filter using a realistic approach. The systematic trend of the data seems to disagree with the thermal shape fluctuation model (TSFM). The model predicts the gradual increase of GDR width from its ground state value whereas the measured GDR widths appear to remain constant at the ground state value till and increase thereafter, indicating towards a failure of the adiabatic assumption of the model at low temperature.