A modified Nambu–Jona-Lasinio Model with lattice structure is very instructive. It shows several similar problems and their solutions as the Lattice QCD. We study the limits of the large box size, ...small cell size and realistic pion mass. In particular, we study the relation of the discrete (bound state) solutions to the physical scattering states, for example the pion–pion scattering.
The existence of a star with such a large mass means that the equation of state is stiff enough to provide a high enough pressure up to a fairly large central densities,. Such a stiff equation of ...state is possible if the ground state has nucleons as its constituents. This further implies that a purely nucleon ground state may exist till about four times nuclear density which indicates that quarks in the nucleon are strongly bound and that the nucleon nucleon potential is strongly repulsive. We find this to be so in a chiral soliton model for the nucleon which has bound state quarks. We point out that this has important implications for the strong interaction \( \mu_B\) vs T phase diagram.
In recent years there has been a rapidly growing body of experimental evidence for existence of exotic, multiquark hadrons, i.e. mesons which contain additional quarks, beyond the usual ...quark-antiquark pair and baryons which consist of more than three quarks. In all cases with robust evidence they contain at least one heavy quark Q=c or b, the majority including two heavy quarks. Two key theoretical questions have been triggered by these discoveries: (a) how are quarks organized inside these multiquark states -- as compact objects with all quarks within one confinement volume, interacting via color forces, perhaps with an important role played by diquarks, or as deuteron-like hadronic molecules, bound by light-meson exchange? (b) what other multiquark states should we expect? The two questions are tightly intertwined. Each of the interpretations provides a natural explanation of parts of the data, but neither explains all of the data. It is quite possible that both kinds of structures appear in Nature. It may also be the case that certain states are superpositions of the compact and molecular configurations. This Whitepaper brings together contributions from many leading practitioners in the field, representing a wide spectrum of theoretical interpretations. We discuss the importance of future experimental and phenomenological work, which will lead to better understandingof multiquark phenomena in QCD.
The explanation for the origin of families of quarks and leptons and their properties is one of the most promising ways to understand the assumptions of the Standard Model. The Spin-Charge-Family ...theory, which does propose the mechanism for the appearance of families and offers an explanation for all the assumptions of the Standard Model, predicts two decoupled groups of four families. The lightest of the upper four families has stable members, which are correspondingly candidates to constitute the dark matter. We study the weak and the "nuclear" (determined by the colour interaction among the heavy fifth family quarks) scattering of such a very heavy baryon by ordinary nucleons in order to show that the cross-section is very small and consistent with the observation in most experiments so far, provided that the quark mass of this baryon is about 100 TeV or above.
In this work we find that the at the high polar magnetic fields of magnetars,
$B \sim 10^{14-15}$ G, the outermost crust ($\rho < 10^7$ gm/cc) of the star
can become a transverse insulator and a ...filamentary crystal along the field
direction. Also, the transverse conductivity in the crust goes inversely as the
square of polar magnetic field (as $1/B^2$). At these high fields the
transverse crustal currents associated with the polar magnetic field can then
dissipate more effectively via Ohm's law.
In this work we find that the at the high polar magnetic fields of magnetars, \(B \sim 10^{14-15}\) G, the outermost crust (\(\rho < 10^7\) gm/cc) of the star can become a transverse insulator and a ...filamentary crystal along the field direction. Also, the transverse conductivity in the crust goes inversely as the square of polar magnetic field (as \(1/B^2\)). At these high fields the transverse crustal currents associated with the polar magnetic field can then dissipate more effectively via Ohm's law.
Quark matter in a chiral chromodielectric model Broniowski, W; Cibej, M; Kutschera, M ...
Physical review. D, Particles and fields,
1990-Jan-01, 1990-1-00, 19900101, 1990-01-01, Letnik:
41, Številka:
1
Journal Article
Recenzirano
Zero- and finite-temperature quark matter is studied in a chiral chromodielectric model with quark, meson, and chromodielectric degrees of freedom. The mean-field approximation is used. Two cases are ...considered: two-flavor and three-flavor quark matter. It is found that at sufficiently low densities and temperatures the system is in a chirally broken phase, with quarks acquiring effective masses of the order of 100 MeV. At higher densities and/or temperatures a chiral phase transition occurs and the quarks become massless. A comparison with traditional nuclear physics suggests that the chirally broken phase with massive quark gas may be the ground state of matter at densities of the order of a few nuclear saturation densities.
The $\gamma\gamma\to\rho^0\rho^0\to 4 \pi$ reaction shows a broad
"resonance"at 1.5 GeV with no counterpart in the $\rho^+\rho^-$ channel. This
$(J^P,J_z)=(2^+,2)$, $I=0$, and $2$ resonance is ...considered as a candidate for
a $qq\bar q\bar q$ state. We show, however, that it can also be explained by
potential scattering of $\rho^0\rho^0$ via the $\sigma-$ exchange.
The \(\gamma\gamma\to\rho^0\rho^0\to 4 \pi\) reaction shows a broad "resonance"at 1.5 GeV with no counterpart in the \(\rho^+\rho^-\) channel. This \((J^P,J_z)=(2^+,2)\), \(I=0\), and \(2\) resonance ...is considered as a candidate for a \(qq\bar q\bar q\) state. We show, however, that it can also be explained by potential scattering of \(\rho^0\rho^0\) via the \(\sigma-\) exchange.
