118850251
Quarks and Gluons: A Century of Particle Charges
Introduction: a century of particle charges the electron - the quantum of electricity mass - E=mc" and all that the photon - no charge, no mass the spin - if it's round, it rolls antimatter - a mirror image the nucleus - a whole new ball game the strong force I - nucleons the weak force - a whisper in the night the strong force II - hadrons the quark - the queen of fractions the origin of quarks and gluons epligoue - m-re quarks, more leptons and more charges. Appendices: annotated chronology powers of ten Nobel prizes in physics.
120561444
Comment on the paper entitled «On the Poincaré noninvariance of a recent alternative to the Dirac equation»
120403374
THREE-TRIPLET MODEL WITH DOUBLE SU(3) SYMMETRY
121619492
A possible mechanism for CP nonconservation
122507140
Diquark color excitation and the narrow resonances
The new narrow resonances are interpreted in the three-triplet model with integral baryon numbers as diquark color excitations of the qq +- q-barq-bar type. Hadronic decays, ..gamma.. transitions, and coupling to ..gamma.. occur through impurity qq-bar admixtures. Except for the coupling to ..gamma.., all decay rates are suppressed. The enhancements above 4 GeV in hadronic cross sections are attributed to qq-bar color octets or still higher diquark levels. (AIP)
123307684
Hadronic regge sequences as primitive realizations of SL(3,R) symmetry☆
Abstract Four primitive infinite dimensional unitary representations of the group of rotations and deformations - SL(3,R) - are constructed and associated with the four Regge trajectories: π, ϱ, N, Δ. The model predicts E2 transition moments and a power law for E versus j consistent with the Chew-Frautschi relation E∼j 1 2 .
119310822
Asymptotics of Spinfoam Amplitude on Simplicial Manifold: Euclidean Theory
We study the large-j asymptotics of the Euclidean EPRL/FK spin foam amplitude on a 4D simplicial complex with arbitrary number of simplices. We show that for a critical configuration {jf, gve, nef} in general, there exists a partition of the simplicial complex into three regions: non-degenerate region, type-A degenerate region and type-B degenerate region. On both the non-degenerate and type-A degenerate regions, the critical configuration implies a non-degenerate Euclidean geometry, while on the type-B degenerate region, the critical configuration implies a vector geometry. Furthermore we can split the non-degenerate and type-A regions into sub-complexes according to the sign of Euclidean-oriented 4-simplex volume. On each sub-complex, the spin foam amplitude at the critical configuration gives a Regge action that contains a sign factor sgn (V4(v)) of the oriented 4-simplex volume. Therefore the Regge action reproduced here can be viewed as a discretized Palatini action with the on-shell connection. The asymptotic formula of the spin foam amplitude is given by a sum of the amplitudes evaluated at all possible critical configurations, which are the products of the amplitudes associated with different type of geometries.
119144559
Cosmological Constant in LQG Vertex Amplitude
A new q-deformation of the Euclidean EPRL/FK vertex amplitude is proposed by using the evaluation of the Vassiliev invariant associated with a 4-simplex graph (related to two copies of quantum SU(2) group at different roots of unity) embedded in a 3-sphere. We show that the large-j asymptotics of the q-deformed vertex amplitude gives the Regge action with a cosmological constant. In the end we also discuss its relation with a Chern-Simons theory on the boundary of 4-simplex.
53976028
Commuting simplicity and closure constraints for 4D spin-foam models
Spin Foam Models are supposed to be discretised path integrals for quantum gravity constructed from the Plebanski-Holst action. The reason for there being several models currently under consideration is that no consensus has been reached for how to implement the simplicity constraints. Indeed, none of these models strictly follows from the original path integral with commuting B elds, rather, by some non standard manipulations one always ends up with non commuting B elds and the simplicity constraints become in fact anomalous which is the source for there being several inequivalent strategies to circumvent the associated problems. In this article, we construct a new Euclidian Spin Foam Model which is constructed by standard methods from the Plebanski-Holst path integral with commuting B elds discretised on a 4D simplicial complex. The resulting model diers from the current ones in several aspects, one of them being that the closure constraint needs special care. Only when dropping the closure constraint by hand and only in the large spin limit can the vertex amplitudes of this model be related to those of the FK Model but even then the face and edge amplitude dier. Interestingly, a non-commutative deformation of the B IJ variables leads from our new model to the BarrettCrane Model in the case of = 1.
14607839
Exhaustive ghost solutions to Einstein-Weyl equations for two dimensional spacetimes
Exhaustive ghost solutions to Einstein-Weyl equations for two dimensional spacetimes are obtained, where the ghost neutrinos propagate in the background spacetime, but do not influence the background spacetime due to the vanishing stress-energy-momentum tensor for the ghost neutrinos. Especially, those non-trivial ghost solutions provide a counterexample to the traditional claim that the Einstein-Hilbert action has no meaningful two dimensional analogue.
27131029
Canonical path integral measures for Holst and Plebanski gravity: I. Reduced phase space derivation
An important aspect in defining a path integral quantum theory is the determination of the correct measure. For interacting theories and theories with constraints, this is non-trivial, and is normally not the heuristic 'Lebesgue measure' usually used. There have been many determinations of a measure for gravity in the literature, but none for the Palatini or Holst formulations of gravity. Furthermore, the relations between different resulting measures for different formulations of gravity are usually not discussed. In this paper we use the reduced phase technique in order to derive the path-integral measure for the Palatini and Holst formulation of gravity, which is different from the Lebesgue measure up to local measure factors which depend on the spacetime volume element and spatial volume element. From this path integral for the Holst formulation of general relativity we can also give a new derivation of the Plebanski path integral and discover a discrepancy with the result due to Buffenoir, Henneaux, Noui and Roche whose origin we resolve. This paper is the first in a series that aims at better understanding the relation between canonical loop quantum gravity and the spin-foam approach.