Related papers: Chirality distributions inside baryons in ${\rm QC…
We have computed the baryon spectrum in the context of $\mathcal{N} = 4$ super-conformal Yang-Mills theory using AdS/CFT duality. Baryons are included in the theory by adding an open string sector, corresponding to quarks in the fundamental…
That chiral symmetry is a crucial feature of the strong force was realized before the discovery of Quantum Chromodynamics. However, the full power it exerts on the structure of the nucleon became apparent only afterwards. We present a…
Infra-red properties of the triangle anomaly and the ``anomaly pole'' are elaborated and applied to the study of high-energy scattering in QCD, when the gauge symmetry is partially broken to SU(2). It is shown that the chiral flavor anomaly…
Lattice studies suggest that at zero baryon chemical potential and increasing temperature there are three characteristic regimes in QCD that are connected by smooth analytical crossovers: a hadron gas regime at T < T_ch ~ 155 MeV, an…
We study the properties and couplings of hybrid baryons in the large-$N_c$ expansion. These are color-neutral baryon states which contain in addition to $N_c$ quarks also one constituent gluon. Hybrid baryons with both symmetric and mixed…
We present preliminary results for the chiral behavior of charged pseudo-Goldstone-boson masses and decay constants. These are obtained in simulations with N_f=2+1 flavors of tree-level, O(a)-improved Wilson sea quarks. In these…
The strange quark plays a unique role in QCD, reflecting its intermediate mass between the light and heavy quarks. In recent years, remarkable progress has been made in the spectroscopy of baryons with strangeness. Many new features of the…
We analyse the baryon mass spectrum in a framework which combines the 1/Nc expansion with chiral perturbation theory. Meson loop contributions involving the full SU(3) octet of pseudoscalar Goldstone bosons are evaluated, and the influence…
We review the open-charm spectrum of chiral excitations in QCD. At leading order in a chiral expansion a parameter-free prediction is obtained for the coupled-channel scattering of Goldstone bosons off open-charm mesons and baryons with…
We study the relation between chiral and $U_A(1)$ symmetries in the quark-meson model. Although quarks and mesons are described in mean field approximation, the topological susceptibility characterizing the $U_A(1)$ breaking comprises two…
We investigate the physical consequences of the survival of the effects of the U(1)_A anomaly in the chiral symmetric phase of QCD, and show that the free energy density is a singular function of the quark mass m, in the chiral limit, and…
We discuss meson-meson scattering at next-to-next-to-leading order in the chiral expansion for QCD-like theories with general $n$ degenerate flavours for the cases with a complex, real and pseudo-real representation. I.e. with global…
Quantum chromodynamics is a fundamental non-abelian gauge theory of strong interactions. The physical quantum chromodynamics vacuum state, $|\theta\rangle$, is a linear superposition of the $n$-vacua states with different topological…
We argue that the charge fractionalization in quarks has a hidden topological character related to a broken ${\cal Z}_2$ symmetry between integer-charged bare quarks and leptons. The mechanism is a tunneling process occurring in time…
Corrections to meson/ground-state baryon scattering amplitudes in the 1/N_c expansion of QCD have previously been shown to be controlled by the t-channel difference |I_t - J_t| of isospin and angular momentum and by the change of…
We compute nonanalytical pion-loop corrections to baryon masses in a combined expansion in chiral symmetry breaking and 1/N_c, where N_c is the number of colors. Specifically, we compute flavor-27 baryon mass splittings at leading order in…
The generalization of QCD to many colors is not unique; each distinct choice corresponds to a distinct 1/N_c expansion. The familiar 't Hooft N_c -> \infty limit places quarks in the fundamental representation of SU(N_c), while an…
In a string picture of hadrons, spins are distributed over the whole configuration of string. According to this picture, spin of hadron is discussed in a dual gravity theory of QCD, towards realistic mass formulae of hadrons including…
Starting from the multi-local Klein-Gordon equations with Lorentz-scalar squared-mass operator we give a covariant quark representation of the general composite mesons and baryons with definite Lorentz transformation property. The…
We study baryons of arbitrary isospin in a stringy holographic QCD model. In this D4-D8 holographic setting, the flavor symmetry is promoted to a gauge symmetry in the bulk, and produces, as KK modes of the gauge field, pions and spin one…