Artículos de revistas
Low temperature s-shaped heat capacities in finite nuclei
Autor
CIVITARESE , O.
HESS , P. O.
HIRSCH , J. G.
Institución
Resumen
EN EL LIMITE TERMODINÁMICO UNA TRANSICIÓN DE FASE ESTÁ ASOCIADA A UN PICO BIEN DEFINIDO EN EL CALOR ESPECIFICO. POR OTRO LADO, EN SISTEMAS FINITOS COMO LOS NÚCLEOS ATÓMICOS SE ENCUENTREN ELEVACIONES ANCHAS EN EL CALOR ESPECIFICO QUE NO REPRESENTAN UNA TRANSFORMACIÓN DE FASE. ESTOS APARECEN DEBIDO A LA EXISTENCIA DE NIVELES AISLADOS DE BAJA ENERGÍA A TRAVÉS DEL EFECTO SCHOTTKY LOCAL. SE PRESENTAN EJEMPLOS DE ESTE COMPORTAMIENTO PARA NÚCLEOS DEFORMADOS PESADOS Y LIGEROS, Y EMPLEANDO TANTO NIVELES DE ENERGÍA EXPERIMENTALES COMO ESPECTROS CALCULADOS EN UN MODELO SENCILLO.AbstractWHILE 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. 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.