arXiv subjects

Chung-I Tan

Publications and source records attributed to Chung-I Tan.

59 records · Page 4Linked to original sources

arXiv1994

Chirally Extended Quantum Chromodynamics

We propose an extended Quantum Chromodynamics (XQCD) Lagrangian in which the fermions are coupled to elementary scalar %$σ$ and $π$ fields through a Yukawa coupling which preserves chiral invariance. Our principle motivation is to find a new lattice formulation for QCD which avoids the source of critical slowing down usually encountered as the bare quark mass is tuned to the chiral limit. The phase diagram and the weak coupling limit for XQCD are studied. They suggest a conjecture that the continuum limit of XQCD is the same as the continuum limit of conventional lattice formulation of QCD. As examples of such universality, we present the large N solutions of two prototype models for XQCD, in which the mass of the spurious pion and sigma resonance go to infinity with the cut-off. Even if the universality conjecture turns out to be false, we believe that XQCD will still be useful as a low energy effective action for QCD phenomenology on the lattice. Numerical simulations are recommended to further investigate the possible benefits of XQCD in extracting QCD predictions. Postscript files for figures are attached. Search for strings "fig11.ps", "fig22.ps", "fig33.ps".

hep-lat↗

arXiv1994

High energy scattering in 2+1 QCD

High energy scattering in 2+1 QCD is studied using the recent approach of Verlinde and Verlinde. We calculate the color singlet part of the quark-quark scattering exactly within this approach, and discuss some physical implication of this result. We also demonstrate, by two independent methods, that reggeization fails for the color singlet channel. We briefly comment on the problem in 3+1 QCD.

hep-th↗

arXiv1993

Heterotic Pomeron: A Unified Treatment of High Energy Hadronic Collisions in QCD

A unified treatment of high energy collisions in QCD is presented. Using a probabilistic approach, we incorporate both perturbative (hard) and non-perturbative (soft) components in a consistent fashion, leading to a ``Heterotic Pomeron". As a Regge trajectory, it is nonlinear, approaching 1 in the limit $t\rightarrow -\infty$.

hep-ph↗

arXiv1993

Ideal Gas of Strings and QCD at Hadronic Scales

By using lessons learned from modern string studies, we show how interesting non-perturbative features of QCD can be learned from future heavy ion collisions even if the deconfinement density is not reached.

hep-th↗

arXiv1992

Symmetry Breaking in the Double-Well Hermitian Matrix Models

We study symmetry breaking in $Z_2$ symmetric large $N$ matrix models. In the planar approximation for both the symmetric double-well $ϕ^4$ model and the symmetric Penner model, we find there is an infinite family of broken symmetry solutions characterized by different sets of recursion coefficients $R_n$ and $S_n$ that all lead to identical free energies and eigenvalue densities. These solutions can be parameterized by an arbitrary angle $θ(x)$, for each value of $x = n/N < 1$. In the double scaling limit, this class reduces to a smaller family of solutions with distinct free energies already at the torus level. For the double-well $ϕ^4$ theory the double scaling string equations are parameterized by a conserved angular momentum parameter in the range $0 \le l < \infty$ and a single arbitrary $U(1)$ phase angle.

hep-th↗