Related papers: Towards a Dynamical Solution of the Strong CP Prob…
A possible solution to the strong CP problem is presented without using an axion. The model is based on the framework of the supersymmetric vectorlike theory with the spontaneous breakdown of the P-C-T-invariance. It is shown that the…
QCD at finite temperature and density is becoming increasingly important for various experimental programmes, ranging from heavy ion physics to astro-particle physics. The non-perturbative nature of non-abelian quantum field theories at…
The strong coupling limit of lattice QCD with staggered fermions has been studied for decades, both via Monte Carlo and via mean field theory. In this model, the finite density sign problem can be made mild and the full phase diagram can be…
We investigate the phase diagram and critical behavior of a three-dimensional lattice CP(N-1) model in the large-N limit. Numerical evidence of first-order transitions is always observed for sufficiently large values of N, i.e. N>2 up to…
The search for a new source of CP violation is one of the most important endeavors in particle physics. A particularly interesting way to perform this search is to probe the CP phase in the $h\tau\tau$ coupling, as the phase is currently…
A brief review is given of the sign problem in finite density lattice QCD and various attempts to overcome it. To date there is still no solution to this problem which would work for realistic QCD. The main focus then is on the deconfined…
The QED(0+1) model describing a quantum mechanical particle on a circle with minimal electromagnetic interaction and with a potential -M cos(phi - theta_M), which mimics the massive Schwinger model, is discussed as a prototype of mechanisms…
I review recent developments in determining the QCD phase diagram by means of lattice simulations. Since the invention of methods to side-step the sign problem a few years ago, a number of additional variants have been proposed, and…
Motivated by the intimate connection between the strong CP problem and the flavor structure of the Standard Model, we present a flavor model that revives and extends the classic ${m_u=0}$ solution to the strong CP problem. QCD is embedded…
A spontaneously-broken CP provides an alternative to the KM mechanism for CP violation with the advantage that the strong CP problem is solved. We consider, for such a model with a new gauged U(1), the incorporation of low-energy…
We discuss a possible solution to the strong CP problem which is based on spontaneous CP violation and discrete symmetries. At the same time we predict in a simple way the almost right-angled quark unitarity triangle angle ($\alpha \simeq…
We give a brief introduction on finite temperature phase transitions in lattice QCD including a discussion on the identification of first order transitions. We present a study of the deconfinement phase transition of one-flavour QCD, using…
A recent work combined the popular left-right parity (LR) and Peccei-Quinn (PQ) symmetries to explain the alignment in quark masses. Since axions may not exist, we break PQ softly and discover a new solution to the strong CP problem.…
A $\theta$ term in lattice field theory causes the sign problem in Monte Carlo simulations. This problem can be circumvented by Fourier-transforming the topological charge distribution $P(Q)$. This strategy, however, has a limitation,…
The CP-restoring phase transition at theta = pi and high temperature is investigated using two related models that aim to describe the low-energy phenomenology of QCD, the NJL model and the linear sigma model coupled to quarks. Despite many…
Ambiguities regarding the physics and the existence of the critical point (CP) on the QCD phase boundary still exist and the mist regarding the conjectured QCD phase boundary has not yet cleared. In this paper we extend our earlier study…
We suggest a new solution to the strong CP problem. The solution is based on the proper use of the boundary conditions for the QCD generating functional integral. We expand the perturbative boundary conditions to both perturbative and…
We present a new mechanism to solve the strong CP problem using $N\geq2$ axions, each dynamically relaxing part of the $\bar\theta$ parameter. At high energies $M\gg\Lambda_{QCD}$ the $SU(3)_{c}$ group becomes the diagonal subgroup of an…
We demonstrate that at finite density and sufficiently high temperatures, phase-quenched (PQ) lattice simulations combined with perturbation theory provide a new precision approach to determining the thermodynamics of QCD across a wide arc…
We investigate the stability of Quantum Critical Points (QCPs) in the presence of two competing phases. These phases near QCPs are assumed to be either classical or quantum and assumed to repulsively interact via square-square interactions.…