14 documents found, page 1 of 2

Spontaneous magnetization under a pseudovector interaction between quarks in hi...

A practical scheme for constructing the minimum-weight states of the su(n)-Lipk...

With the aim of performing an argument supplementary to the previous paper by the present authors [Y. Tsue, C. Providência, J. da Providência, and M.Yamamura, Prog. Theor. Exp. Phys. 2017, 081D01 (2017)], in this paper, a practical scheme for constructing the minimum-weight states of the su(n)-Lipkin model in arbitrary fermion number is discussed. The idea comes from the following two points: (i) consideration ...

A note on the Lipkin model in arbitrary fermion number

A possible form of the Lipkin model obeying the su(6) algebra is presented. It is a natural generalization from the idea for the su(4) algebra recently proposed by the present authors. All the relations appearing in the present form can be expressed in terms of spherical tensors in the su(2) algebras. For specifying the linearly independent basis completely, twenty parameters are introduced. It is concluded tha...

Spin Polarized versus Chiral Condensate in Quark Matter at Finite Temperature a...

25 pages, 9 figures; It is shown that the spin polarized condensate appears in quark matter at high baryon density and low temperature due to the tensor-type four-point interaction in the Nambu-Jona-Lasinio-type model as a low energy effective theory of quantum chromodynamics. It is indicated within this low energy effective model that the chiral symmetry is broken again by the spin polarized condensate as incr...

A possible framework of the Lipkin model obeying the SU(n) algebra in arbitrary...

The minimum weight states of the Lipkin model consisting of n single-particle levels and obeying the SU(n) algebra are investigated systematically. The basic idea is to use the SU(2) algebra, which is independent of the SU(n) algebra. This idea has already been presented by the present authors in the case of the conventional Lipkin model consisting of two single-particle levels and obeying the SU(2) algebra. If...

A possible framework of the Lipkin model obeying the SU(n) algebra in arbitrary...

Based on the results for the minimum weight states obtained in the previous paper (I), an idea of how to construct the linearly independent basis is proposed for the SU(n) Lipkin model. This idea starts in setting up m independent SU(2) subalgebras in the cases with n = 2m and n = 2m+1 (m = 2, 3, 4, . . .). The original representation is re-formed in terms of the spherical tensors for the SU(n) generators built...

Spontaneous magnetization in high-density quark matter

19 pages, 3 figures; It is shown that the spontaneous magnetization occurs due to the anomalous magnetic moments of quarks in the high-density quark matter under the tensor-type four-point interaction. The spin polarized condensate for each flavor of quark appears at high baryon density, which leads to the spontaneous magnetization due to the anomalous magnetic moments of quarks. The implications to the strong ...

New boson realization of the Lipkin model obeying the su(2)-algebra

7 pages, no figure; New boson representation of the su(2)-algebra proposed by the present authors for describing the damped and amplified oscillator is examined in the Lipkin model as one of simple many-fermion models. This boson representation is expressed in terms of two kinds of bosons with a certain positive parameter. In order to describe the case of any fermion number, third boson is introduced. Through t...

Spin Polarization versus Color-Flavor-Locking in High Density Quark Matter

23 pages, 4 figures; It is shown that spin polarization with respect to each flavor in three-flavor quark matter occurs instead of the color-flavor locking at high baryon density by using the Nambu-Jona-Lasinio model with four-point tensor-type interaction. Also, it is indicated that the order of phase transition between the color-flavor locked phase and the spin polarized phase is the first order by means of t...

Beyond the Schwinger boson representation of the su(2)-algebra. I -- New boson ...

31 pages, 6 figures; With the use of two kinds of boson operators, a new boson representation of the su(2)-algebra is proposed. The basic idea comes from the pseudo su(1,1)-algebra recently given by the present authors. It forms a striking contrast to the Schwinger boson representation of the su(2)-algebra which is also based on two kinds of bosons. This representation may be suitable for describing time-depend...