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We examine the construction of the spin angular momentum in systems with pseudoclassical Grassmann variables. In constrained systems there are many different algebraic forms for the dynamical variables that will all agree on the constraint surface. For the angular momentum, a particular form of the generators is preferred, which yields superselection sectors of irreducible spin^c(n) representations rather than reducible so(n) representations when quantized in the Schr\"odinger realization., Comment: 7 pages. Published version

We examine the quantization of pseudoclassical dynamical systems, models that have classically anticommuting variables, in the Schrodinger picture. We quantize these systems, which can be viewed as classical models of particle spin, using the generalized Gupta–Bleuler method as well as the reduced phase space method in even dimensions. With minimal modifications, the standard constructions of Schrodinger quantum mechanics of constrained systems work for pseudoclassical systems. We generalize the standard Schrodinger norm and implement the correct adjointness properties of observables and constraints. We construct the state space corresponding to spinors as physical wave functions of anticommuting variables, finding that there are superselection sectors in both the physical and ghost subspaces. The physical states are isomorphic to those of the Dirac–Kahler formulation of fermions, though the inner product in Dirac–Kahler theory is not equivalent to ours.

Motivated by nonrelativistic models of a QCD (quantum chromodynamic) string, we examine the systemof a nonrelativistic string in uniform rotational motion with one endfixed and with a mass (quark) attached to the other end. A QCD string hasno purely longitudinal modes, so some constraint must be imposed upon thenonrelativistic system to exclude these modes. Accordingly, we examinethe cases that the string is either inextensible or purely transverse. Foreach case we solve first the discretized string and then do the continuumcase. We find the small amplitude oscillatory motions and frequencies ofoscillation of the string and mass. We show that the assumption of a nodeat the end of the inextensible string produces frequencies that are veryclose to the actual frequencies. For the transverse string, we show thatkeeping centrifugal terms for the motion of the masses comprising thestring leads to an unstable mode.PACS Nos.: 03.20.+i, 03.40.-t, 12.39.Mk

Starting from Buchm{umlt u}ller{close_quote}s observation that a chromoelectric flux tube meson will exhibit only the Thomas-type spin-orbit interaction, we show that a model built upon the related assumption that a quark feels only a constant radial chromoelectric field in its rest frame implies a complete relativistic effective Hamiltonian that can be written explicitly in terms of quark canonical variables. The model yields linear Regge trajectories and exhibits some similarities to scalar confinement, but with the advantage of being more closely linked to QCD. {copyright} {ital 1997} {ital The American Physical Society}

In this Letter the method of Lund is applied to formulate a variational principle for the motion of charged vortices in an effective non-linear Schr\"{o}dinger field theory describing finite size two-dimensional quantum Hall samples under the influence of an arbitrary perpendicular magnetic field. Freezing out variations in the modulus of the effective field yields a $U(1)$ sigma-model. A duality transformation on the sigma-model reduces the problem to finding the Green function for a related electrostatics problem. This duality illuminates the plasma analogy to the Laughlin wave function., Comment: 7 pp., Plain TeX (macros included), MAD/TH-92-03

We examine the issue of duality both in electrodynamics and in Kalb-Ramond scalar axion systems. In D space-time dimensions the dual abelian theories of (p −1)- and (D − p − 1)-form potentials have vacua classified by the dimensions of the cohomology spaces Hp − 1((D − 1)M) or HD − p −((D − 1)M), respectively. The vacua are characterized by topological charges which are expectation values for generalized “Wilson loop” operators around non-trivial cycles. In certain instances the vacua exhibit a theta angle parametrization much as in QCD. The relation of axionic hair and discrete gauge hair is analyzed in the topologically massive Kalb-Ramond theory. If there are no fundamental strings in the theory, axionic charge is replaced by an irrelevant vacuum angle.

It is demonstrated that charged particles may acquire unusual statistics in topologically nontrivial two-dimensional samples placed in strong magnetic fields. These novel statistics follow from an analysis of the self-adjoint extensions of the Landau hamiltonian which are partially classified by the UIR's of the fundamental group. Superselection rules corresponding to different quantum theories are found. Supersymmetry arguments are used to construct exact ground states.

The 4-dimensional theory of a 1-form Abelian gauge field A coupled to a 2-form (antisymmetric tensor) potential B is studied. The two gauge invariances of the theory admit a coupling mB ∧ F where F is the field strength (F=dA) of A. It is shown that this theory is a unitary, renormalizable theory of a massive spin-one field with no additional degrees of freedom. In this sense, it is a generalization to four dimensions of topological mechanisms in two dimensions (the Schwinger model) and three dimensions (Chern-Simons theory). The issue of spontaneous symmetry breaking is also examined.

As a step toward a fundamental understanding of hybrid states we demonstrate the close relationship between the relativistic string and lattice simulation results for excited glue states with two fixed color sources.

A black hole may carry axionic charge in a theory which has gravity coupled to a massless two-form Kalb-Ramond field. We show that this effect persists if the axion has a topological mass term coupling the Kalb-Ramond potential to a U(1) gauge field. Such mass terms arise in the low-energy effective theory of the string.

We construct a consistent action for a massive spinning quark on the end of a QCD string that leads to pure Thomas precession of the quark's spin. The string action is modified by the addition of Grassmann degrees of freedom to the string such that the equations of motion for the quark spin follow from boundary conditions, just as do those for the quark's position., Comment: REVTeX4, 10 pages, no figures

The concept of Lorentz scalar quark confinement has a long history and is still widely used despite its well-known theoretical faults. We point out here that the predictions of scalar confinement also conflict directly with experiment. We investigate the dependence of heavy-light meson mass differences on the mass of the light quark. In particular, we examine the strange and non-strange D mesons. We find that the predictions of scalar confinement are in considerable conflict with measured values., Comment: REVTeX4, 7 pages, 4 EPS figures

We demonstrate the equivalence of the relativistic flux tube model of mesons to a simple potential model in the regime of large radial excitation. We make no restriction on the quark masses; either quark may have a zero or finite mass. Our primary result shows that for fixed angular momentum and large radial excitation, the flux tube/QCD string meson with a short-range Coulomb interaction is described by a spinless Salpeter equation with a time component vector potential V(r) = ar - k/r., Comment: RevTeX4, 10 pages, 3 eps figures

Clean predictions are presented for all the spin-averaged heavy-light meson spectroscopies. A new symmetry is identified wherein the energy eigenstates have a universal dependence on both the light and heavy quark masses. This universality is used in an efficient analysis of these mesons within the QCD string/flux tube picture. Unique predictions for all the D, D_s, B, and B_s type mesons in terms of just four measured quantities., Comment: REVTeX4, 6 pages, 9 eps figures

We demonstrate that the Nambu-Goto string spectroscopy with massless quarks is replicated in highly excited states of the linear vector confinement potential. For deep radial excitations we observe that the Regge slope, spacing between daughter trajectories, and absolute state energies agree with those of the QCD string., 4 pages, 4 figures, REVTeX4. Version to appear in Phys. Rev. D. Section II substantially improved, references added

We perform an analytic semi-classical quantization of the straight QCD string with one end fixed and a massless quark on the other, in the limits of orbital and radial dominant motion. Our results well approximate those of the exact numerical semi-classical quantization as well as our exact numerical canonical quantization.

We perform an analytic semi-classical quantization of the straight QCD string with one end fixed and a massless quark on the other, in the limits of orbital and radial dominant motion. We compare our results to the exact numerical semi-classical quantization. We observe that the numerical semi-classical quantization agrees well with our exact numerical canonical quantization., Comment: RevTeX, 10 pages, 9 figures

We outline a connection between scalar quark confinement, a phenomenologically successful concept heretofore lacking fundamental justification, and QCD. Although scalar confinement does not follow from QCD, there is an interesting and close relationship between them. We develop a simple model intermediate between scalar confinement and the QCD string for illustrative purposes. Finally, we find the bound state masses of scalar, time-component vector, and string confinement analytically through semi-classical quantization., ReVTeX, 9 pages, 5 figures

The computation of mode sums of the types encountered in basic quantum field theoretic applications is addressed with an emphasis on their expansions into functions of distance that can be interpreted as potentials. We show how to regularize and calculate the Casimir energy for the continuum Nambu-Goto string with massive ends as well as for the discrete Isgur-Paton non-relativistic string with massive ends. As an additional example, we examine the effect on the interquark potential of a constant Kalb-Ramond field strength interacting with a QCD string., 10 pages ReVTeX, 3 PostScript figures. Introductory material and references added. To appear in Phys Rev D

We consider the effects of going beyond the approximation of a straight string in mesons by using a flexible flux tube model wherein a Nambu-Goto string bends in response to quark accelerations. The curved string is dynamically identical to the straight string even for ultra-relativistic mesons except for a small additional radial momentum. We numerically solve the curved string model in the case where both ends have equal mass quarks and also the case where one end is fixed. No approximation of non-relativistic motion is made. We note some small but interesting difference from the straight string., Comment: 12 pages REVTeX, 10 PostScript Figures

It is well known that a straight Nambu-Goto string is an exact solution of the equations of motion when its end moves in a circular orbit. In this paper we investigate the shape of a confining relativistic string for a general motion of its end. We determine analytically the shape of the curved string to leading order in deviation from straightness, and show that it reduces to an expected non-relativistic result. We also demonstrate numerically that in realistic meson models this deviation is always small. We further find that the angular momentum and energy are the same as for the straight string, but that the curved string has a small radial momentum not present in a straight string. Our results justify the common assumption of straight strings usually made in hadron models., 17 pages LaTeX, 4 figures. Version to appear in Phys Rev D

Recent lattice results for the energy of gluonic excitations as a function of quark separation are shown to correspond to transverse relativistic flux tube vibration modes. For large quark separations all states appear to degenerate into a few categories which are predicted uniquely, given the ground state., Comment: 10 pages, 3 figures, LaTeX, references added and minor corrections

We examine two methods for incorporating complex first-class constraints into the BRST formalism when the complex conjugates of the constraints are linearly dependent upon the constraints, as is the case for general relativity in the Ashtekar variables.

We show that the harmonic Becchi-Rouet-Stora-Tyutin method of quantizing bosonic systems with second-class constraints or first-class holomorphic constraints extends to systems having both bosonic and fermionic second-class or first-class holomorphic constraints. Using a limit argument, we show that the harmonic BRST modified path integral reproduces the correct Senjanovic measure., 11 pages, phyzzx

A new ‘harmonic’ BRST method is presented for quantizing those dynamical systems having second-class constraints which split into holomorphic and antiholomorphic algebras. These theories include those whose phase spaces are coadjoint orbits of a compact semisimple Lie group. The method also applies to theories with holomorphic first-class constraints which have nonvanishing brackets with their antiholomorphic conjugates. An operatorial quantization, resembling supersymmetric quantum mechanics, is presented. In addition, a general path integral is given and is shown to reduce to that given by Batalin, Fradkin, and Vilkovisky.

We derive explicit forms for the neutrino and lepton "mixing-matrices" which describe the generic singular see-saw model. The dependence on the hierarchy parameter is contrasted with the non-singular case. Application is made to Simpson's 17 keV neutrino.

Both the Green-Schwarz and Siegel strings are presented in canonical form. Both systems are shown to describe the same number of physical degrees of freedom. The apparent extra symmetries of the Siegel string are not true symmetries but are combinations of second-class constraints. A formal quantization procedure is outlined and the problems of quantization are discussed.

AS THE NUMBER OF children in . fected with the human im munodeficiency virus (HIV) and pediatric acquired immune deficiency syndrome (AIDS) cases grows nation wide, the mutual problems and con cerns of child welfare and health care agencies point to the need for increas ing collaboration between the two com munities. Numerous media reports have described the astronomical costs of pro viding health care to persons with AIDS. The increasing number of HIV infected "boarder babies" who remain in acute care hospital beds is un necessarily costly and does not allow for the provision of love, care, and stimula tion essential to infant development. Child welfare agencies are being asked to assume custody and find foster homes for these children. The health care community is assuming greater responsibility not only in treating these children but also in educating the public about AIDS and in attempting to allay the fears of potential foster parents. The cooperative efforts in New Jersey between the child welfare and health care communities represent a signifi cant effort to challenge and overcome the territorial boundaries that can pre vent the provision of critical services to HIV-infected children and to their fami lies. This article describes the col laborative effort between the New Jersey Department of Human Services, Division of Youth and Family Services (DYFS), and the Children's Hospital AIDS Program (CHAP) of New Jersey.

The primordial mass density fluctuations may have arisen from quantum fluctuations in a (massless) scalar field that occurred during an inflationary era. We show that it is possible for primordial mass density fluctuations, which arose in this way, to be highly non-gaussian. We also show that the “bad” infrared properties of the propagator for a massless scalar field in de Sitter space can translate itself into a power spectrum, for the two-point spatial correlation of objects that do not trace the mass, which behaves like k−3, at small wave numbers k.

Dirac’s procedure is applied to the Brink-Schwarz and Siegel superparticle systems. Both systems are exhibited to have the same first-class constraints. The difference between the systems is the lack of second-class fermionic constraints in the Siegel superparticle. Thus the Siegel superparticle has a phase space with twice as many fermionic degrees of freedom as the Brink-Schwarz superparticle.

It is demonstrated that the unitary propagator is obtained from the pseudoclassical system proposed as a first-quantized version of the Dirac particle by Berezin and Marinov. The action for the system is written in a form which has manifest global supersymmetry on the worldline.