Low temperature s-shaped heat capacities in finite nuclei
2004; Mexican Society of Physics; Volume: 50; Issue: 4 Linguagem: Inglês
ISSN
2683-2224
AutoresO. Civitarese, Peter O. Hess, Jorge G. Hirsch,
Tópico(s)Cold Atom Physics and Bose-Einstein Condensates
ResumoEN EL LIMITE TERMODINAMICO UNA TRANSICION DE FASE ESTA ASOCIADA A UN PICO BIEN DEFINIDO EN EL CALOR ESPECIFICO. POR OTRO LADO, EN SISTEMAS FINITOS COMO LOS NUCLEOS ATOMICOS SE ENCUENTREN ELEVACIONES ANCHAS EN EL CALOR ESPECIFICO QUE NO REPRESENTAN UNA TRANSFORMACION DE FASE. ESTOS APARECEN DEBIDO A LA EXISTENCIA DE NIVELES AISLADOS DE BAJA ENERGIA A TRAVES DEL EFECTO SCHOTTKY LOCAL. SE PRESENTAN EJEMPLOS DE ESTE COMPORTAMIENTO PARA NUCLEOS DEFORMADOS PESADOS Y LIGEROS, Y EMPLEANDO TANTO NIVELES DE ENERGIA EXPERIMENTALES COMO ESPECTROS CALCULADOS EN UN MODELO SENCILLO. Abstract WHILE IN THE THERMODYNAMIC LIMIT A PHASE TRANSITION IS SIGNALED BY THE PRESENCE OF A SHARP PEAK IN THE SPECIFIC HEAT, IN FINITE SYSTEMS A BUMP IS USUALLY FOUND. HOWEVER, THERE ARE RELEVANT CASES IN WHICH THE PRESENCE OF A LOW-TEMPERATURE BUMP IN THE CANONICAL SPECIFIC HEAT OF ATOMIC NUCLEI IS LINKED TO THE EXISTENCE OF ISOLATED LOW ENERGY STATES THROUGH A LOCAL SCHOTTKY EFFECT, AND DO NOT REPRESENT A PHASE TRANSITION. EXAMPLES ARE PRESENTED FOR LIGHT AND HEAVY DEFORMED NUCLEI, BY USING IN THE CALCULATIONS EXPERIMENTAL AND THEORETICAL ENERGY LEVELS.
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