Abstract
The representation theory of the recently introduced proton-neutron symplectic model in the many-particle Hilbert space is considered. The relation of the Sp(12, R) irreducible representations (irreps) with the shell-model classification of the basis states is considered by extending of the state space to the direct product space of SU p (3) ⊗ SU n (3) irreps, generalizing in this way the Elliott’s SU(3) model for the case of two-component system. The Sp(12, R) model appears then as a natural multi-major-shell extension of the generalized proton-neutron SU(3) scheme, which takes into account the core collective excitations of monopole and quadrupole, as well as dipole type associated with the giant resonance vibrational degrees of freedom. Each Sp(12, R) irreducible representation is determined by a symplectic bandhead or an intrinsic U(6) space which can be fixed by the underlying proton-neutron shell-model structure, so the theory becomes completely compatible with the Pauli principle. It is shown that this intrinsic U(6) structure is of vital importance for the appearance of the low-lying collective bands without involving a mixing of different symplectic irreps. The full range of low-lying collective states can then be described by the microscopically based intrinsic U(6) structure, renormalized by coupling to the giant resonance vibrations.
Similar content being viewed by others
References
A. Bohm, Y. Ne'eman, A.O. Barut (Editors), Dynamical Groups and Spectrum generating Algebras, Vols. 1 and 2 (World Scientific Publishing Co. Pte. Ltd., Singapore, 1988).
R.F. Casten (Editor), Algebraic Approaches to Nuclear Structure: Interacting Boson and Fermion Models (Harwood Academic Publishers, New York, 1993).
F. Iachello, Lie Algebras and Applications, in Lecture Notes in Physics, Vol. 708 (Springer-Verlag, Berlin Heidelberg, 2006).
A. Frank, P.V. Isacker, J. Jolie, Symmetries in Atomic Nuclei: From Isospin to Supersymmetry, in Springer Tracks in Modern Physics, Vol. 230 (Springer-Verlag, New York, 2009).
D.J. Rowe, J.L. Wood, Fundamentals of Nuclear Models: Foundational Models (World Scientific Publisher Press, Singapore, 2010).
G. Rosensteel, D.J. Rowe, Ann. Phys. 96, 1 (1976).
G. Rosensteel, D.J. Rowe, Ann. Phys. 123, 36 (1978).
D.J. Rowe, G. Rosensteel, Ann. Phys. 126, 198 (1980).
O.L. Weaver, R.Y. Cussion, L.C. Biedenharn, Ann. Phys. (N.Y.) 102, 493 (1976).
L. Weaver, L.C. Biedenharn, Nucl. Phys. A 185, 1 (1972).
H. Ui, Prog. Theor. Phys. 44, 153 (1970).
L. Weaver, R.Y. Cusson, L.C. Biedenharn, Ann. Phys. (N.Y.) 77, 250 (1973).
D.J. Rowe, G. Rosensteel, Phys. Rev. Lett. 38, 10 (1977).
V.V. Vanagas, Methods of the theory of group representations and separation of collective degrees of freedom in the nucleus, in Lecture notes at the Moscow Engineering Physics Institute (MIFI, Moscow, 1974) (in Russian).
V. Vanagas, Fiz. Elem. Chastits At. Yadra. 7, 309 (1976) (Sov. J. Part. Nucl. 7.
H.G. Ganev, Eur. Phys. J. A 50, 183 (2014).
J.P. Elliott, Proc. R. Soc. London Ser. A 245, 128 (1958).
J.P. Elliott, Proc. R. Soc. London Ser. A 245, 562 (1958).
G.F. Filippov, V.I. Ovcharenko, Yu.F. Smirnov, Microscopic Theory of Collective Excitations in Nuclei (Naukova Dumka, Kiev, 1981) (in Russian). .
M. Moshinsky, C. Quesne, J. Math. Phys. 11, 1631 (1970).
V.V. Vanagas, Algebraic foundations of microscopic nuclear theory (Nauka, Moscow, 1988) (in Russian).
D.J. Rowe, M.J. Carvalho, J. Repka, Rev. Mod. Phys. 84, 711 (2012).
A. Georgieva, P. Raychev, R. Roussev, J. Phys. G 8, 1377 (1982).
F. Iachello, A. Arima, The Interacting Boson Model (Cambridge University Press, Cambridge, 1987).
H. Ganev, V.P. Garistov, A.I. Georgieva, Phys. Rev. C 69, 014305 (2004).
V. Vanagas, E. Nadjakov, P. Raychev, Preprint Trieste TC/75/40 (1975).
V. Vanagas, E. Nadjakov, P. Raychev, Bulg. J. Phys. 2, 558 (1975).
N. Lo Iudice, F. Palumbo, Phys. Rev. Lett. 41, 1532 (1978).
N. Lo Iudice, F. Palumbo, Nucl. Phys. A 326, 193 (1979).
O. Castanos, J.P. Draayer, Y. Leschber, Ann. Phys. 180, 290 (1987).
G. Rosensteel, D.J. Rowe, Phys. Rev. Lett. 46, 1119 (1981).
M.J. Carvalho, D.J. Rowe, S. Karram, C. Bahri, Nucl. Phys. A 703, 167 (1987).
O. Castanos, P.O. Hess, J.P. Draayer, P. Rochford, Nucl. Phys. A 524, 469 (1991).
D. Troltenier, J.P. Draayer, P.O. Hess, O. Castanos, Nucl. Phys. A 576, 351 (1994).
S.G. Nilsson, Dan. Mat. Fys. Medd. 29, 1 (1955).
R.D. Ratnnu Raju, J.P. Draayer, K.T. Hecht, Nucl. Phys. A 202, 433 (1973).
J.P. Draayer, K.J. Weeks, Ann. Phys. 156, 41 (1984).
J.P. Draayer, K.J. Weeks, K.T. Hecht, Nucl. Phys. A 381, 1 (1982).
J. Carvalho et al., Nucl. Phys. A 452, 240 (1986).
D.J. Rowe, Rep. Prog. Phys. 48, 1419 (1985).
V.V. Vanagas, Algebraic methods in nuclear theory (Mintis, Vilnius, 1971) (in Russian).
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by D. Blaschke
Rights and permissions
About this article
Cite this article
Ganev, H.G. Shell-model representations of the proton-neutron symplectic model. Eur. Phys. J. A 51, 84 (2015). https://doi.org/10.1140/epja/i2015-15084-1
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1140/epja/i2015-15084-1