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Papers by Alejandro Frank
arXiv (Cornell University), May 9, 2001
In order to investigate to what extent is the low-lying behavior of even-even nuclei dependent on... more In order to investigate to what extent is the low-lying behavior of even-even nuclei dependent on particular nucleon-nucleon interactions, we consider systems of bosons where these interactions are taken as gaussian random numbers with equal likelyhood of being attractive or repulsive. We find a statistical dominance of L = 0 ground states and other correlations, which we analyze in terms of a mean field approach. Para investigar hasta que punto el comportamiento de los núcleos está determinado por interacciones particulares entre los nucleones, consideramos sistemas de bosones con interacciones gaussianas aleatorias, donde dichas interacciones tienen la misma probabilidad de ser atractivas o repulsivas. Encontramos un dominio estadístico de estados base L = 0 y otras correlaciones, que analizamos en términos de un método de campo medio.
arXiv (Cornell University), Feb 27, 2009
The Hispalensis Lectures on Nuclear Physics Vol. 2, 2004
The main ideas behind nuclear supersymmetry are presented, starting from the basic concepts of sy... more The main ideas behind nuclear supersymmetry are presented, starting from the basic concepts of symmetry and the methods of group theory in physics. We propose new, more stringent experimental tests that probe the supersymmetry classification in nuclei and point out that specific correlations should exist for particle transfer intensities among supersymmetric partners. We also discuss possible ways to generalize these ideas to cases where no dynamical symmetries are present. The combination of these theoretical and experimental studies may play a unifying role in nuclear phenomena.
AIP Conference Proceedings, 1995
A consistent baryon mapping oC colorless three-quark clustcrs is proposed and tested in thc conte... more A consistent baryon mapping oC colorless three-quark clustcrs is proposed and tested in thc context oC a three-color extcnsion oC the Lipkin model. The results suggest that baryon mappings may provide a practical means oC deriving nuclei Crom constituent quark rnodels. RESUMEN. Se propone en Corma consistente un mapeo bariónico de agrupamientos de tres quarks acoplados a color cero. El mapeo se pone a prueba en el contexto de una extensión de tres colores del modelo de Lipkin. Los resultados sugieren que los mapeos bariónÍCos podrian dar lugar a métodos prácticos de derivación de la estructura de los núcleos a partir de modelos de quarks constituyentes.
![Research paper thumbnail of New supersymmetric quartet of nuclei: [sup 192,193]Os-[sup 193,194]Ir](https://attachments.academia-assets.com/119735779/thumbnails/1.jpg)
](AIP Conference Proceedings, 2009
We present evidence for the existence of a new supersymmetric quartet of nuclei in the A ∼ 190 ma... more We present evidence for the existence of a new supersymmetric quartet of nuclei in the A ∼ 190 mass region. The analysis is based on new experimental information on the odd-odd nucleus 194 Ir from transfer and neutron capture reactions. The new data allow the identification of a new supersymmetric quartet, consisting of the 192,193 Os and 193,194 Ir nuclei. We make explicit predictions for 193 Os, and suggest that its spectroscopic properties be measured in dedicated experiments. Finally, we study correlations between different transfer reactions.
Symmetries in Nuclear Structure, 2004
Symmetries in Nuclear Structure, 2004
Nuclear Physics News, 2001
International Journal of Modern Physics E, 2008
A review of recent advances in the theoretical analysis of nuclear mass models and their predicti... more A review of recent advances in the theoretical analysis of nuclear mass models and their predictive power is presented. After introducing two tests which probe the ability of nuclear mass models to extrapolate, three models are analyzed in detail: the liquid drop model (LDM), the liquid drop model plus empirical shell corrections (LDMM) and the Duflo–Zuker mass formula (DZ). The DZ model is exhibited as the most predictive model. The Garvey–Kelson mass relations are also discussed. It is shown that their fulfillment probes the consistency of the most commonly used mass formulae, and that they can be used in an iterative process to predict nuclear masses in the neighborhood of nuclei with measured masses, offering a simple and reproducible procedure for short range mass predictions.
Physics Letters B, 1986
The relation between the pseudo-L scheme and the Nilsson model is discussed within the context of... more The relation between the pseudo-L scheme and the Nilsson model is discussed within the context of SU (3) dynamical symmetry limits of boson-fermion models of odd-mass nuclei. It is shown that the pseudo-L approach incorporates certain nonadiabatic effects which modify the effective Coriolis matrix elements, thus offering a possible explanation for their observed deviation from experiment.
Physical Review Letters, 2005
Physical Review C, 2001
Transfer reactions constitute a stringent test for nuclear supersymmetry, a theory that simultane... more Transfer reactions constitute a stringent test for nuclear supersymmetry, a theory that simultaneously describes neighboring nuclei with bosonic and fermionic character. We construct and analytically evaluate one-nucleon transfer matrix elements between supersymmetric partners with the U (6/4) case as an example, and stress the need for a careful treatment of bosonic and fermionic operators in the construction of mixed tensor operators.
Physical Review C, 1987
We show that the SU(3) limit of the U( ) model used to describe asymmetric shape deforma- tion in... more We show that the SU(3) limit of the U( ) model used to describe asymmetric shape deforma- tion in even-even nuclei may be simply extended to odd-mass nuclei. The extension results in decoupling parameters with opposite signs in opposite-parity bands. We discuss the model in con-
Physical Review C, 1994
We present a new and consistent mapping of colorless three-quark clusters onto colorless triplet ... more We present a new and consistent mapping of colorless three-quark clusters onto colorless triplet fermions (baryons) and test it in the context of a three-color extension of the Lipkin model. For systems with two triplets (for which the problem can be solved without approximation both before and after the mapping), we exactly reproduce the dynamics of the model for the variety of correlation structures considered.
arXiv (Cornell University), May 9, 2001
In order to investigate to what extent is the low-lying behavior of even-even nuclei dependent on... more In order to investigate to what extent is the low-lying behavior of even-even nuclei dependent on particular nucleon-nucleon interactions, we consider systems of bosons where these interactions are taken as gaussian random numbers with equal likelyhood of being attractive or repulsive. We find a statistical dominance of L = 0 ground states and other correlations, which we analyze in terms of a mean field approach. Para investigar hasta que punto el comportamiento de los núcleos está determinado por interacciones particulares entre los nucleones, consideramos sistemas de bosones con interacciones gaussianas aleatorias, donde dichas interacciones tienen la misma probabilidad de ser atractivas o repulsivas. Encontramos un dominio estadístico de estados base L = 0 y otras correlaciones, que analizamos en términos de un método de campo medio.
arXiv (Cornell University), Feb 27, 2009
The Hispalensis Lectures on Nuclear Physics Vol. 2, 2004
The main ideas behind nuclear supersymmetry are presented, starting from the basic concepts of sy... more The main ideas behind nuclear supersymmetry are presented, starting from the basic concepts of symmetry and the methods of group theory in physics. We propose new, more stringent experimental tests that probe the supersymmetry classification in nuclei and point out that specific correlations should exist for particle transfer intensities among supersymmetric partners. We also discuss possible ways to generalize these ideas to cases where no dynamical symmetries are present. The combination of these theoretical and experimental studies may play a unifying role in nuclear phenomena.
AIP Conference Proceedings, 1995
A consistent baryon mapping oC colorless three-quark clustcrs is proposed and tested in thc conte... more A consistent baryon mapping oC colorless three-quark clustcrs is proposed and tested in thc context oC a three-color extcnsion oC the Lipkin model. The results suggest that baryon mappings may provide a practical means oC deriving nuclei Crom constituent quark rnodels. RESUMEN. Se propone en Corma consistente un mapeo bariónico de agrupamientos de tres quarks acoplados a color cero. El mapeo se pone a prueba en el contexto de una extensión de tres colores del modelo de Lipkin. Los resultados sugieren que los mapeos bariónÍCos podrian dar lugar a métodos prácticos de derivación de la estructura de los núcleos a partir de modelos de quarks constituyentes.
AIP Conference Proceedings, 2009
We present evidence for the existence of a new supersymmetric quartet of nuclei in the A ∼ 190 ma... more We present evidence for the existence of a new supersymmetric quartet of nuclei in the A ∼ 190 mass region. The analysis is based on new experimental information on the odd-odd nucleus 194 Ir from transfer and neutron capture reactions. The new data allow the identification of a new supersymmetric quartet, consisting of the 192,193 Os and 193,194 Ir nuclei. We make explicit predictions for 193 Os, and suggest that its spectroscopic properties be measured in dedicated experiments. Finally, we study correlations between different transfer reactions.
Symmetries in Nuclear Structure, 2004
Symmetries in Nuclear Structure, 2004
Nuclear Physics News, 2001
International Journal of Modern Physics E, 2008
A review of recent advances in the theoretical analysis of nuclear mass models and their predicti... more A review of recent advances in the theoretical analysis of nuclear mass models and their predictive power is presented. After introducing two tests which probe the ability of nuclear mass models to extrapolate, three models are analyzed in detail: the liquid drop model (LDM), the liquid drop model plus empirical shell corrections (LDMM) and the Duflo–Zuker mass formula (DZ). The DZ model is exhibited as the most predictive model. The Garvey–Kelson mass relations are also discussed. It is shown that their fulfillment probes the consistency of the most commonly used mass formulae, and that they can be used in an iterative process to predict nuclear masses in the neighborhood of nuclei with measured masses, offering a simple and reproducible procedure for short range mass predictions.
Physics Letters B, 1986
The relation between the pseudo-L scheme and the Nilsson model is discussed within the context of... more The relation between the pseudo-L scheme and the Nilsson model is discussed within the context of SU (3) dynamical symmetry limits of boson-fermion models of odd-mass nuclei. It is shown that the pseudo-L approach incorporates certain nonadiabatic effects which modify the effective Coriolis matrix elements, thus offering a possible explanation for their observed deviation from experiment.
Physical Review Letters, 2005
Physical Review C, 2001
Transfer reactions constitute a stringent test for nuclear supersymmetry, a theory that simultane... more Transfer reactions constitute a stringent test for nuclear supersymmetry, a theory that simultaneously describes neighboring nuclei with bosonic and fermionic character. We construct and analytically evaluate one-nucleon transfer matrix elements between supersymmetric partners with the U (6/4) case as an example, and stress the need for a careful treatment of bosonic and fermionic operators in the construction of mixed tensor operators.
Physical Review C, 1987
We show that the SU(3) limit of the U( ) model used to describe asymmetric shape deforma- tion in... more We show that the SU(3) limit of the U( ) model used to describe asymmetric shape deforma- tion in even-even nuclei may be simply extended to odd-mass nuclei. The extension results in decoupling parameters with opposite signs in opposite-parity bands. We discuss the model in con-
Physical Review C, 1994
We present a new and consistent mapping of colorless three-quark clusters onto colorless triplet ... more We present a new and consistent mapping of colorless three-quark clusters onto colorless triplet fermions (baryons) and test it in the context of a three-color extension of the Lipkin model. For systems with two triplets (for which the problem can be solved without approximation both before and after the mapping), we exactly reproduce the dynamics of the model for the variety of correlation structures considered.