Hadronic Regge Trajectories Research Articles

Light-front holographic distribution amplitudes of pseudoscalar mesons and their application to B -meson decays

In this paper the dynamical spin effects of the light-front holographic wavefunctions for light pseudoscalar mesons are studied using two different assumptions. These improved wavefunctions are then confronted with a number of sensitive hadronic observables: the decay constants of $\pi$ and $K$ mesons, their $\xi$-moments, the pion-to-photon transition form factor, and the pure annihilation $\bar{B}_{s}\to \pi^+ \pi^-$ and $\bar{B}_{d}\to K^+K^-$ decays. Taking $f_{\pi}$, $f_{K}$ and their ratio $f_{K}/f_{\pi}$ as constraint conditions, the $\chi^2$ analyses for holographic parameters, including the mass scale parameter $\sqrt{\lambda}$ and effective quark masses, are all consistent with the mass scale which controls the slopes of the light-quark hadronic Regge trajectories. In addition, we also show how the improved light-front holographic distribution amplitudes regulate the end-point divergences which appear in the annihilation amplitudes of $B\to PP$ decays.

Glueball masses and Regge trajectories for the QCD-inspired potential

The bound state of two massive constituent gluons is studied in the potential approach. The relativistic quasi-classical wave equation with the QCD-inspired scalar potential is solved by the quasi-classical method in the complex plane. Glueball masses are calculated with the help of the universal mass formula. The hadron Regge trajectories are given by the complex non-linear function in the whole region of the invariant variable t. The Chew–Frautschi plot of the leading glueball trajectory, α P (t), has the properties of a t-channel Pomeron, which is dual to the glueball states in the s channel. The imaginary part of the Pomeron is also calculated.

Making confining strings out of mesons

The light mesons such as $\ensuremath{\pi}$, $\ensuremath{\rho}$, $\ensuremath{\omega}$, ${f}_{0}$, and ${a}_{0}$ are possible candidates of magnetic degrees of freedom, if a magnetic dual picture of QCD exists. We construct a linear sigma model to describe spontaneous breaking of the magnetic gauge group, in which there is a stable vortex configuration of vector and scalar mesons. We numerically examine whether such a string can be interpreted as the confining string. By using meson masses and couplings as inputs, we calculate the tension of the string as well as the strength of the Coulomb force between static quarks. They are found to be consistent with those inferred from the quarkonium spectrum and the Regge trajectories of hadrons. By using the same Lagrangian, the critical temperature of the QCD phase transition is estimated, and a nontrivial flavor dependence is predicted. We also discuss a possible connection between the Seiberg duality and the magnetic model we studied.

Low-energy properties of hadrons in the relativistic quark model

The properties of light and heavy mesons, baryons and tetraquarks are discussed within a QCD-motivated relativistic quark model. The results for the mass spectra, electroweak properties and Regge trajectories of hadrons are presented.

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.

Thermal time scales in a color glass condensate

In a model of relativistic heavy ion collisions wherein the unconfined quark-gluon plasma is condensed into glass, we derive the Vogel-Fulcher-Tammann cooling law. This law is well known to hold true in condensed matter glasses. The high energy plasma is initially created in a very hot negative temperature state and cools down to the Hagedorn glass temperature at an ever decreasing rate. The cooling rate is largely determined by the QCD string tension derived from hadronic Regge trajectories. The ultimately slow relaxation time is a defining characteristic of a color glass condensate.

Hadronic Regge trajectories: Problems and approaches

We scrutinized hadronic Regge trajectories in a framework of two different models --- string and potential. Our results are compared with broad spectrum of existing theoretical quark models and all experimental data from PDG98. It was recognized that Regge trajectories for mesons and baryons are not straight and parallel lines in general in the current resonance region both experimentally and theoretically, but very often have appreciable curvature, which is flavor-dependent. For a set of baryon Regge trajectories this fact is well described in the considered potential model. The standard string models predict linear trajectories at high angular momenta J with some form of nonlinearity at low J.

Effective functional form of Regge trajectories

We present theoretical arguments and strong phenomenological evidence that hadronic Regge trajectories are essentially nonlinear and can be well approximated, for phenomenological purposes, by a specific square-root form.

Effect of color screening on heavy quarkonia Regge trajectories

Using an unquenched lattice potential to calculate the spectrum of a bottomonium-like system, we demonstrate numerically that the effect of pair creation is to produce termination of the real part of hadronic Regge trajectories, in contrast to the Veneziano model and the vast majority of phenomenological generalizations. Termination of the real part of Regge trajectories may have significant experimental consequences.

A Rotating Bag Model for Hadrons. II: Regge Trajectories of Baryons

The MIT bag model is modified in order to describe rotational motion of hadrons. It has a kind of «diatomic molecular» structure. The rotational excitation of the MIT bag is described by the polarized two colored sub-bags which are connected with each other by the gluon flux. One sub-bag contains a quark and the other has an antiquark for mesons. For baryons, the latter sub-bag contains the remaining two quarks instead of the antiquark. The Regge trajectories of hadrons are explained qualitatively by our new model with the usual MIT bag parameters. In particular the Regge slopes are reproduced fairly well. It is also pointed out that the gluon flux plays an important role in the rotational motion of hadrons

Quark-Orbital Regge Trajectories

It is shown that the pattern of Regge trajectories of hadrons becomes very much simpler and more regular than the usual Chew-Frautschi plot when one uses the orbital angular mo­ mentum of the quarks in a hadron instead of the spin of the meson and the spin minus 1/2 of the baryon, as the Reggeized angular momentum. Available data on particles and resonances are classified by means of the quark-orbital Regge trajectories, and as a result of it, the following pattern appears: there are linear rising quark-orbital trajectories with the universal slope for each irreducible representation of SU(6); actual hadron spectra are reproduced by adding the spin- and unitary spin-exchange interactions and the mass shift of the .l-quark. The Gell-Mann-Okubo mass formula holds rather good including resonances with high mass. Effects of the spin-orbit interaction are clearly recognized and its magnitude is nearly of the same order as those of the spin- and unitary spin-exchange interactions for mesons, whereas they are not so obvious for baryons. It follows from this splitting pattern of the quark-orbital Regge trajectories that the exchange degeneracies hold better for mesons than for baryons and that many doublets exist apparently and several parity partners should not appear, in conformity with experimental data. Classification of resonances using the orbital angular momentum between incoming two hadrons does not show much regularity. It is suggested from these results that strong interactions are essentially characterized by the degree of freedom of the spatial motion at the urbaryon level. § I. Introduction The fact that the hadron spectra obey the classification due to SU(6) @0 (3) very well*l and that the properties of the exotic and nonexotic channels are quite different, seems to show the importance of pursuing seriously the consequences of the quark model. On the other hand, we also recognize the importance of analytic properties of amplitudes, especially the Regge trajectories. Then the following question arises naturally: Which is the most important quantity that essentially determines the dynamics of strong interactions: the three angular momenta, total angular momentum of a hadron (denoted by J in the following), total orbital angular momentum of a hadron in the quark model (denoted by L) or the total orbital angular momentum of hadrons in the most dominant decay mode of the hadron (denoted by l)? It is the purpose of this paper to shed some light on this question by a comprehensive investigation of experimental data on hadron spectra. We will discuss the classification of mesons and baryons in the quark model in § 2 and *> This does not necessarily mean that the SU(6) symmetry applies to the wholeS-matrix as