Related papers: The nonperturbative origin of delta-function singu…
Dynamical chiral symmetry breaking is a nonperturbative phenomenon that may be studied using QCD's gap equation. Model-independent results can be obtained with a nonperturbative and symmetry preserving truncation. The gap equation yields…
Under the assumption of Abelian dominance in QCD, we have shown that chiral condensate is locally present around each QCD monopole. The essence is that either of charge or chirality of a quark is not conserved, when the low energy massless…
Using chiral symmetry we investigate the leading SU(3) violation in the complete set of quark twist-3 light-cone distribution functions of the pion, kaon, and eta. It is shown that terms non-analytic in the quark masses do not affect the…
The isospin asymmetry of the sea quark distribution as well as the unexpectedly small quark spin fraction of the nucleon are two outstanding discoveries recently made in the physics of deep-inelastic structure functions. We evaluate here…
While chiral symmetry breaking in the QCD vacuum is attributed to nonzero chiral condensate, an alternative symmetry breaking pattern with no chiral condensate is also possible, as pointed out by Stern. This hypothetical phase was excluded…
We present a study of the QCD interactions which do not conserve the chirality of quarks. These non-perturbative forces are responsible for the violation of the U_A(1) charge conservation and for the breaking of chiral symmetry. From a…
The mass function of the nonperturbative quark propagator in SU(3) gauge theory shows only a weak dependence on the vortex content of the gauge configurations. Of particular note is the survival of dynamical mass generation on vortex-free…
We define twist-two and twist-three quark fragmentation functions in Quantum Chromodynamics (QCD) and study their physical implications. Using this formalism we show how the nucleon's transversity distribution can be measured in single pion…
We evaluate the complete leading-order evolution kernels for the chiral-odd twist-3 distributions $e(x)$ and $\widetilde h_L(x)$ of the nucleon. We establish the connection between the evolution equations in light-cone position and…
We present a determination, from lattice QCD, of charge symmetry violation in the spin- independent and spin-dependent parton distribution functions of the nucleon. This is done by chirally extrapolating recent QCDSF/UKQCD Collaboration…
We have revisited the calculation of the neutron electric dipole moment in the presence of the CP-violating operators up to dimension five based on the chiral perturbation theory. Especially, we focus on the contribution of strangeness…
We study spontaneous symmetry breaking in one dimensional quantum mechanical problems in terms of two-point boundary problems which lead to singular potentials containing Dirac delta functions and its derivatives. We search for…
In this talk, which popularizes some of our recent work, we provide novel insights into the bulk properties of light chiral quarks in a fixed Euclidean volume (e.g. lattice QCD). We show that the spontaneous breakdown of chiral symmetry…
We study the QCD evolution for the twist-three quark-gluon correlation functions associated with the transverse momentum odd quark distributions. Different from that for the leading twist quark distributions, these evolution equations…
The nucleon sigma term of the isoscalar and isovector quark chromo-magnetic dipole moments are essential inputs for the determination of the CP-odd pion-nucleon couplings induced by quark chromo-electric dipole moments. We demonstrate that…
A model for the QCD vacuum based on domain-like background gluon fields has previously been developed and demonstrated to exhibit confinement of quarks and strong correlation of the local chirality of quark modes and duality of the…
We examine Dashen's phenomenon in the Leutwyler--Smilga regime of QCD with any number of colors and quarks in either the fundamental or adjoint representations of the gauge group. In this limit, the theories only depend on simple…
On a null-plane (light-front), all effects of spontaneous chiral symmetry breaking are contained in the three Hamiltonians (dynamical Poincar\'e generators), while the vacuum state is a chiral invariant. This property is used to give a…
In the first part of the talk, I review what we know (or rather do not know) about the structure of the QCD vacuum in the presence of strange quarks. Chiral perturbation theory allows to study reactions of pions and kaons and to further…
We study quantum chromodynamics including the two-index symmetric or anti-symmetric quark (QCD(Sym/ASym)) on small $\mathbb{R}^2\times T^2$ with a suitable magnetic flux. We first discuss the 't Hooft anomaly of these theories and claim…