Magnetic Symmetry,Regge Trajectories,and the Linear Confinement in Dual QCD

Using the magnetic symmetry structure of non-Abelian gauge theories, we analyze the flux tube formulation and its implications on the hadronic Regge trajectories and the confinement of color isocharges in magnetically condensed (with as well as without the electric excitations) QCD vacuum. Starting with the fiber bundle structure of QCD, the dual potentials are used to construct the QCD Lagrangian which has been shown to develop a unique flux tube configuration in its dynamically broken phase. The vector mass mode of the condensed vacuum has been shown to play a leading role in flux tube energy and other confinement parameters. Using the flux tube energy and the angular momentum, the Regge trajectories for hadrons have been obtained and the linear confining properties of dual QCD have been established. The dyonic flux tube structure of the condensed QCD vacuum has been obtained by inducing the electric excitation of QCD monopoles and the confining nature along with the linearity of Regge trajectories in dyonically condensed QCD vacuum are shown to remain intact. Implications of the modification in Regge slope parameter, on improving the confining properties of dual QCD vacuum are also discussed. PACS: 12.38.Aw; 11.30.-j; 14.80.Hv; 12.39.Mk An erratum to this article is available at .     

Spectrum and Regge trajectories in QCD

Starting in the 1960s, an active group of physicists under the guidance of Prof. K.A. Ter-Martirosyan began creating the theory of high-energy processes in QCD. From the beginning, the key element of this theory is the notion of Regge trajectories and, in particular, of the Pomeron trajectory, which have been introduced phenomenologically. In this talk, I review the problem of the spectrum and Regge trajectories as it can be derived from nonperturbative QCD dynamics.     

Regge theory and QCD in large-angle scattering

We argue that exclusive processes whose cross-sections are determined by Regge pole trajectory exchanges, α(t), at small momentum transfers (t), are controlled by these same exchanges at very large |t| too. The analysis is based on a Reggeized version of the constituent interchange model (CIM), which predicts that α(t)→?1 ast→?∞, and that the asymptotic form of the Regge residues is fixed by the dimensional counting rules and CIM constraints. Between the two regimes of soft and hard scattering there is an intermediate region where Regge cuts are important, but these higher-twist effects die away as |t| is increased. We show that this hypothesis is consistent with high energy nucleon-nucleon and pion-nucleon scattering at all angles.     

Threshold Behaviour of Simple and Double Regge Pole Trajectories

The threshold behaviour of simple and double Regge pole trajectories is studied. It is shown that for a number of cases two particle unitarity gives rise to moving J-plane zeros, colliding at threshold with Regge poles. Conditions are found for which Regge trajectories near the threshold S = S₀ have square-root behaviour independent of the value of α(S₀).     

Light-Front Holography,Color Confinement,and Supersymmetric Features of QCD

Light-Front Quantization—Dirac’s “Front Form”—provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes are defined from the hadronic light-front wavefunctions. One obtains new insights into the hadronic spectrum, light-front wavefunctions, and the functional form of the QCD running coupling in the nonperturbative domain using light-front holography—the duality between the front form and AdS₅, the space of isometries of the conformal group. In addition, superconformal algebra leads to remarkable supersymmetric relations between mesons and baryons of the same parity. The mass scale \({\kappa}\) underlying confinement and hadron masses can be connected to the parameter \({\Lambda_{\overline {MS}}}\) in the QCD running coupling by matching the nonperturbative dynamics, as described by the effective conformal theory mapped to the light-front and its embedding in AdS space, to the perturbative QCD regime. The result is an effective coupling defined at all momenta. This matching of the high and low momentum transfer regimes determines a scale Q₀ which sets the interface between perturbative and nonperturbative hadron dynamics. The use of Q₀ to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with the principle of maximal conformality for setting the renormalization scales, can greatly improve the precision of perturbative QCD predictions for collider phenomenology. The absence of vacuum excitations of the causal, frame-independent front form vacuum has important consequences for the cosmological constant. I also discuss evidence that the antishadowing of nuclear structure functions is non-universal; i.e., flavor dependent, and why shadowing and antishadowing phenomena may be incompatible with the momentum and other sum rules for nuclear parton distribution functions.     

Regge asymptotics of scattering with flavour exchange in QCD

We investigate the dynamical possibility for the formation of a transient new coherent condition of matter in high-energy hadronic collisions. The coherent bosonic amplitude is characterized by a non-zero mementum and is sustained byP-wave interactions of quasi-pions in a dense fermionic medium. We make quantitative estimates of several essential properties: the condensate momentum and the fermionic density, the zize of the coherent amplitude and the negative energy density contributed by the condensate, a characteristic proper time for the system to exist prior to breakdown into a few pions, and a characteristic extension of the system over the plane perpendicular to the collision axis. These quantities then allow us to make definite estimates of new signals: a few pions with anomalously small transverse momenta <-50 mev/c;=" and=" a=" possible=" anomalous=" bremsstrahlung=" of=" very=" soft=" photons=" with=" characteristic=" transverse=" momenta=" as=" low=" as=" about=" 4=">     

Regge asymptotics of scattering amplitudes in the logarithmic approximation of QCD

The method of separation is applied to the calculation of scattering amplitudes in the Regge region. The method allows to represent the nonladder contributions in a simple form. The result for the amplitude with quark-antiquark exchange and positive signature is discussed.     

Short distance Regge singularities. Renormalized gluon ladder in QCD

It is shown that the renormalized gluon ladder gives rise to an accumulation of Regge poles at j = +1. This approximation is obtained by reordering the perturbation expansion of the Bethe-Salpeter kernel using the renormalization group. The existence of this accumulation is shown to be independent of the gauge. The relevance of this result for the problem of the Pomeron is discussed briefly.     

Dynamical Model of QCD Vacuum and Quark Confinement

The phase transition of a simple local gauge model is investigated in termsof the Nambu-Jona-Lasinio mechanism and it is pointed out that thephysical vacuum of QCD is bound state of quark-antiquark pairs which can beviewed, generally, as a nearly perfect color dia-electric medium. Animportant relation between the vacuum expectation value of gauge fields andscalar fields is also derived by solving the Euler equation for the gaugefields. Based on this relation the SU_C(3) gauge potential is given which can be used to explain the asymptotic behavior and confinement of quarks in a hadron, and at the same time the Yukawa potential of strong interaction can be given too.     

Charmonium production at the Tevatron and Large Hadron Collider in the Regge limit of QCD

Processes involving direct J/ψ-meson production in proton-antiproton and proton-proton collisions are studied under the assumption of gluon Reggeization in t-channel exchanges and with the aid of the formalism of nonrelativistic quantum chromodynamics. The present calculations are performed in the leading approximation in the strong coupling constant α _s and in the relative quark velocity v. The octet nonperturbative matrix elements for the transition of a c $\bar c$ pair to quarkonium are fixed in fitting the transverse-momentumspectra obtained by the CDF Collaboration for J/ψ mesons at the Tevatron collider. The spectra of J/ψ-meson production at the energies of the Large Hadron Collider are predicted, and the resulting predictions agree well with experimental data obtained by the ATLAS, CMS, and LHCb Collaborations at $\sqrt S $ = 7 TeV.     

Deuteron photodisintegration within the Quark-Gluon Strings Model and QCD motivated nonlinear Regge trajectories

We investigate deuteron two-body photodisintegration within the framework of the Quark-Gluon Strings Model with nonlinear baryon Regge trajectories. Special attention is paid to the use of QCD motivated Regge trajectories of the logarithmic and square-root form. We find that the recent experimental data from TJNAF in the few-GeV region can be reasonably described by the model. Angular distributions at different γ-energies are presented and the effect of a forward-backward asymmetry is discussed. Predictions for the energy dependence of dσ/dt at higher energies and different Θ_c.m. are presented, too. Received: 12 March 2001 / Accepted: 19 March 2001     

Enhancement of Laser-induced Breakdown Spectroscopy (LIBS) Signal Subject to the Magnetic Confinement and Dual Pulses

Optics and Spectroscopy - In this work, a comparative study for the laser-induced breakdown spectroscopy (LIBS) of aluminium (Al) target has been performed by using the two kinds of enhancement...     

Symmetry properties of fermionic bilinears in lattice QCD

The 256 fermionic bilinears $\text{ψ}\text{γTψ}$ appearing in the Kogut-Susskind/Kähler-Dirac theory are classified into representations of the hypercubic rotation reflection group; charge conjugation and U(1)_A are also considered. Applications to the study of the normalization of lattice currents are suggested.     

Couplings of the rho meson in a holographic dual of QCD with Regge trajectories

The couplings g_ρHH of the ρ meson with a scalar meson H are calculated in a holographic dual of QCD in which the Regge trajectories for the mesons are manifest. In contrast to the conclusion in general AdS/QCD models, the resulting couplings grow linearly with the quantum number of excited H; thus they are far from universal. This non-universality seems to result from the disappearance of an explicit cutoff in the holographic dimension in this model. Correspondingly, the ρ-dominance for the electromagnetic form factors of H does not hold any more, even in an apparent sign-alternating manner. With these couplings at hand, the asymptotic behavior of the form factors can easily be calculated. The form factor exhibits the 1/Q^(2Δ-2) behavior, which is in accordance with the scaling behavior of the fixed-angle scattering amplitude based on the AdS/CFT correspondence. It is also pointed out that the asymptotic behavior can be matched to the results of perturbative QCD, if the conformal dimension Δ of the operator is replaced by the combination τ+L of the meson. PACS  11.25.Tq; 12.40.Vv; 14.40.Cs     

Three gluon integral equation and odd C singlet Regge singularities in QCD

The integral equation for a three gluon system in the odd C colour singlet channel is derived utilising reggeon calculus based on QCD. This equation is shown to be free from infrared divergences. It generates a fixed branch point near j = 1 as the singularity.