Related papers: Parity doublets in the baryon spectrum
The smallness of the quark and lepton parameters and the hierarchy between them could be the result of selection rules due to a horizontal symmetry broken by a small parameter. The same selection rules apply to baryon number violating…
Properties of high-density strong-interaction matter of relevance for astrophysical scenarios that involve neutron stars are discussed. It is argued that theoretical and experimental insights from the small baryo-chemical potential…
We discuss various mechanisms for the creation of an asymmetric charge fluctuation with respect to the reaction plane among hadrons emitted in relativistic heavy-ion collisions. We show that such mechanisms exist in both, the hadronic gas…
In the covariant level-classification scheme of hadrons based on U(12)SF * O(3,1)L symmetry, the ground state baryons and antibaryons are assigned to the (12 * 12 * 12)Sym = 364-multiplet in the spin-flavor U(12)SF symmetry. This multiplet…
Non-perturbative electroweak effects, in thermal equilibrium in the early universe, have the potential to erase the baryon asymmetry of the universe, unless it is encoded in a B-L asymmetry, or in some "accidentally" conserved quantity. We…
In the framework chiral SU(3) quark model, the baryon spectra within the band of $N\leq 2$ are studied, and the effect of the confining potential in different configurations, namely the $\Delta$-mode and Y-mode are compared. In the same…
I study the consequences of chiral symmetry restoration for the Dirac spectrum in finite-temperature gauge theories in the two-flavor chiral limit, using Ginsparg--Wilson fermions on the lattice. I prove that chiral symmetry is restored at…
I discuss the consequences of the constraints imposed on the Dirac spectrum by the restoration of chiral symmetry in the chiral limit of gauge theories with two light fermion flavors, with particular attention to the fate of the anomalous…
We derive mass formulae for the ground state, J^P = 0^- and 1^-, and first excited even-parity, J^P = 0^+ and 1^+, charmed mesons including one loop chiral corrections and O(1/m_c) counterterms in heavy hadron chiral perturbation theory. We…
Roles of quark-pair correlations in the baryon structure and the hyperon non-leptonic weak decay are studied within the non-relativistic constituent quark model. We construct the SU(3) ground state baryons by solving the three body problem…
Several topics concerning the light hadron spectrum are discussed. Flavor symmetry breaking effects and the problem of quenched chiral logarithm are examined with pion mass data for the Kogut-Susskind quark action, and light meson decay…
We study odd-parity baryonic resonances with one heavy and three light flavors, dynamically generated by meson-baryon interactions. Special attention is paid to Heavy Quark Spin Symmetry (HQSS), hence pseudoscalar and vector mesons and…
We study the low energy part of the nucleon and $\Delta$ spectra by solving the Schr\"{o}dinger equation for the three-quark system in the hyperspherical harmonic approach. The quark-quark hamiltonian considered includes, besides the usual…
In the present talk, we report recent results on electromagnetic properties of the baryon decuplet within the SU(3) chiral quark-soliton model, taking into account the effects of explicit flavor SU(3) symmetry breaking. We focus on the…
We revise the role played by symmetry in the study of the low-lying baryon spectrum and comment on the difficulties when trying to generalize the symmetry pattern to higher energy states. We show that for the $(N,\Delta)$ part such a…
It is argued that the baryon excitations group to four-dimensional partial waves described by means of the three Rarita-Schwinger (RS) fields [(\sigma -1 )/2 ,(\sigma -1)/2]* [(1/2, 0)+(0,1/2)] with \sigma =2,4 and 6, where all components…
I review recent progress and developments in parity-violating electron scattering as it bears on three topics: strange quarks and hadron structure, electroweak radiative corrections, and physics beyond the Standard Model. I also discuss…
The current theoretical status in the analysis and interpretation of low-mass dilepton measurements in (ultra-) relativistic heavy-ion experiments is reviewed. Special emphasis is put on potential signals of (partial) restoration of…
The recently postulated existence of a baryon antidecuplet [1] can be reproduced in strong coupling theory in which a bare baryon spin 1/2 octet interacts with an octet of pseudoscalar mesons. When a suitable mixture of F- and D-type Yukawa…
A key question to QCD is what mechanism generates the hadron mass in the light quark sector, where both confinement and chiral symmetry breaking are in the game. Are confinement and chiral symmetry breaking in the vacuum uniquely…