Goldstone

Goldstone, J., Proc. Roy. Soc. [London] A239, 267, Derivation of the Brueckner many-body theory. ... 

Goldstone, Adrian and Wesley Sweetser. A bibliography of Arthur Machen. University of Texas, 1965 reprint, New York Haskell House, 1973. 179p. ISBN 083831614X... 

Korbonits, M., Goldstone, A. P., Gueorguiev, M. Grossman, A. B. (2004). Ghrelin - a hormone with multiple functions. Front. Neuroendocrinol. 25, 27-68. 

Luttinger-Tisza method is burdened by independent minimization variables, while analysis of the values of the Fourier components F k) makes it possible to immediately exclude no less than half of the variable set and to obtain a result much more quickly. Degeneracy of the ground state occurs either due to coincidence of minimal values of Vt (k) at two boundary points of the first Brillouin zone k = b]/2 and k = b2/2, or as a result of the equality Fj (k) = F2 (k) at the same point k = h/2. The natural consequence of the ground state degeneracy is the presence of a Goldstone mode in the spectrum of orientational vibrations.53... 

The 4>2 particle is known as a Goldstone boson. The important point is that this phenomenon is general. The Goldstone theorem [48] which states that massless scalars occur whenever a continuous symmetry of a physical system is spontaneously broken (or, more accurately, is not apparent in the ground state) will be accepted without further proof, however, compare [49],... 

The particle spectrum consists of a massless Goldstone boson 2, a massive scalar i, and more crucially a massive vector A. The Goldstone boson can be eliminated by gauge transformation. For infinitesimal gauge factor a(x),... 

In order to test this experimental finding we are comparing with the eigenvalues of a Hamiltonian for a realistic quark model, namely the Goldstone-boson-exchange (GBE) constituent quark model (Glozman et al, 1998). It includes the kinetic energy in relativistic form... 

Figure 8. Histograms of the nearest-neighbor spacing distribution for the nucleon (left plots) and the delta (right plots). The data is for Goldstone-boson exchange and for one-gluon exchange compared to a pure linear confinement potential of the same strength. Curves represent the Poisson and the GOE-Wigner distributions.

In the Brueckner-Hartree-Fock (BHF) approximation, the Brueckner-Bethe-Goldstone (BBG) hole-line expansion is truncated at the two-hole-line level [5]. The short-range NN repulsion is treated by a resummation of the particle-particle ladder diagrams into a n effect vc i n tcract ion or G-matrix. Self-consistency is required at the level of the BHF single-particle spectrum eBHF(k),... 

This constraint implicitly defines the matrix, K (4>,gL,gR) Here, we wish to examine the CFL spectrum of massive states using the technique of integrating in/out at the level of the effective Lagrangian. is the Goldstone boson decay... 

This must be contrasted with the situation at zero chemical potential, where the coefficient of the four-derivative term is always a pure number before quantum corrections are taken into account. In vacuum, the tree-level Lagrangian which simultaneously describes vector mesons, Goldstone bosons, and their interactions is ... 

By expanding the effective Lagrangian with the respect to the Goldstone boson fields, one sees that g is also connected to the vector meson coupling to two pions, through the relation... 

At very high quark density the ordinary Goldstone phase is no longer favored compared with a superconductive one associated to the following type of diquark condensates ... 

The validity of the t Hooft anomaly conditions at high matter density have been investigated in [32, 33], A delicate part of the proof presented in [33] is linked necessarily to the infrared behavior of the anomalous three point function. In particular one has to show the emergence of a singularity (i.e. a pole structure). This pole is then interpreted as due to a Goldstone boson when chiral symmetry is spontaneously broken. 

It is also interesting to note that the explicit dependence on the quark chemical potential is communicated to the Goldstone excitations via the coefficients of the effective Lagrangian (see [31] for a review). For example is proportional to fj, in the high chemical potential limit and the low energy effective theory is a good expansion in the number of derivatives which allows to consistently incorporate in the theory the Wess-Zumino-Witten term [32] and its corrections. 

Alternatively, if we had taken rns to be finite for fixed regulator d (so that, as /j, —> oo, eventually rns < m ), the inequality in (60) could be applied to exclude a Nambu-Goldstone boson, but we would find ourselves in the phase without a kaon condensate. 

Note that this phase breaks no global symmetry at all. This is an important point in connection with the identification of the lowest lying excitation modes which in turn strongly influence the thermodynamic properties of the system. In the 2SC phase we do not find, even in the chiral limit, any real Goldstone bosons, although there are some low-lying (pseudo)-Goldstones related to the axial 17,4(1) [15]. 

Because of the spontaneously broken U 1) x 0(3) symmetry in Eq. (3), for A / 0 there should be collective Nambu-Goldstone excitations in the spectrum. However, due to the Lorentz non-invariance of the system there can be subtleties [19, 28-30], The NG spectrum can be analyzed within an underlying effective Higgs potential... 

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