It is shown that the quark mass aligns QCD θ vacuum in such a way that the strong CP is conserved, resolving the strong CP problem. Quantum chromodynamics (QCD) is well established as the fundamental theory for the strong interactions. However, there has been a persistent puzzle with QCD, namely the smallness of the strong CP violation. The most general QCD Lagrangian is given in the form:

Recently, a non-Hermitian chiral random matrix model was proposed to describe the eigenvalues of the QCD Dirac operator at nonzero chemical potential. This matrix model can be constructed from QCD by mapping it to an equivalent matrix model which has the same symmetries as QCD with chemical potential. Its microscopic spectral correlations are conjectured to be identical to those of the QCD Dira...

The order parameter of the chiral phase transition is directly related to the infrared part of the spectrum of the QCD Dirac operator. This part of the spectrum follows from the low energy limit of QCD which is given by a partition function of weakly interacting Goldstone modes. We find that the slope of the Dirac spectrum is determined by the pion decay constant whereas for λ ≪ 1/L 2 Λ QCD the...

Results for the first test of the “crude” QCD continuum model, commonly used in QCD Sum Rule analyses, are presented for baryon correlation functions. The QCD continuum model is found to effectively account for excited state contributions to the short-time regime of two-point correlation functions and allows the isolation of ground state properties. Confusion in the literature surrounding the p...

Using the replica method, we analyze the mass dependence of the QCD 3 partition function in a parameter range where the leading contribution is from the zero momentum Goldstone fields. Three complementary approaches are considered in this article. First, we derive exact relations between the QCD 3 partition function and the QCD 4 partition function continued to half-integer topological charge. ...

There are two distinct pictures of the vacuum structure in QCD. One is based on the appearance of color-magnetic monopoles (QCDmonopoles) after performing the abelian gauge xing [1]. The recent lattice QCD simulations show that the dual Meissner e ect brought to the QCD vacuum by QCD-monopole condensation [2]. Hence, color con nement could be regarded as the dual version of the superconductivit...

We summarize recent developments in our understanding of low-mass quark-antiquark excitations in hadronic matter under various different conditions. This includes the ther-modynamics of the chiral condensate, pions as Goldstone bosons in normal nuclear matter, and excursions into extreme territory of the QCD phase diagram: lepton pair production from a fireball expanding through the transition ...

A code is -quasi-cyclic ( -QC) if there is an integer such that cyclic shift of a codeword by -positions is also a codeword. For = 1, cyclic codes are obtained. A dyadic code is a code which is closed under all dyadic shifts. An -QC dyadic ( -QCD) code is one which is both -QC and dyadic. QCD codes with = 1 give codes that are cyclic and dyadic (CD). In this correspondence, we obtain a simple c...