No Arabic abstract
Within the electroweak theory, it is shown that the form of the total Lagrangian is invariant, under local phase changes of the basis states for leptons and under local changes of the mathematical spaces employed for the description of left-handed spinor states of leptons. In doing this, a contribution from vacuum fluctuations of the leptonic fields, which causes no experimentally-observable effect, is added to the total connection field. Accompanying the above-mentioned changes of basis states, the leptonic and connection fields are found to undergo changes whose forms are similar to $U(1)$ and $SU(2)$ gauge transformations, respectively. These results suggest a simple physical interpretation to gauge symmetries in the electroweak theory.
This paper studies models with extended electroweak gauge sectors of the form SU(2) x SU(2) x U(1) x [SU(2) or U(1)]. We establish the general behavior of corrections to precision electroweak observables in this class of theories and connect our results to previous work on specific models whose electroweak sectors are special cases of our extended group.
This paper proposes new symmetries (the body-centred cubic periodic symmetries) beyond the standard model. Using a free particle expanded Schrodinger equation with the body-centred cubic periodic symmetry condition, the paper deduces a full baryon spectrum (including mass M, I, S, C, B, Q, J and P) of all 116 observed baryons. All quantum numbers of all deduced baryons are completely consistent with the corresponding experimental results. The deduced masses of all 116 baryons agree with (more than average 98 percent) the experimental baryon masses using only four constant parameters. The body-centred cubic periodic symmetries with a periodic constant ``a about $10^{-23}$m play a crucial rule. The results strongly suggest that the new symmetries really exist. This paper predicts some kind of ``Zeeman effect of baryons, for example: one experimental baryon N(1720)${3/2}^{+}$ with $ Gamma$ = 200 Mev is composed of two N baryons [(N(1659)${3/2}^{+}$ + N(1839)${3/2}^{+}$] = $bar{N(1749)}$${3/2}^{+}$ with $Gamma$ = 1839-1659 = 180 Mev.
Invariance properties of classes in the variational sequence suggested to Krupka et al. the idea that there should exist a close correspondence between the notions of variationality of a differential form and invariance of its exterior derivative. It was shown by them that the invariance of a closed Helmholtz form of a dynamical form is equivalent with local variationality of the Lie derivative of the dynamical form, so that the latter is locally the Euler--Lagrange form of a Lagrangian. We show that the corresponding local system of Euler--Lagrange forms is variationally equivalent to a global Euler--Lagrange form.
We discuss some aspects of the relation between dualities and gauge symmetries. Both of these ideas are of course multi-faceted, and we confine ourselves to making two points. Both points are about dualities in string theory, and both have the flavour that two dual theories are closer in content than you might think. For both points, we adopt a simple conception of a duality as an isomorphism between theories: more precisely, as appropriate bijections between the two theories sets of states and sets of quantities. The first point (Section 3) is that this conception of duality meshes with two dual theories being gauge related in the general philosophical sense of being physically equivalent. For a string duality, such as T-duality and gauge/gravity duality, this means taking such features as the radius of a compact dimension, and the dimensionality of spacetime, to be gauge. The second point (Sections 4, 5 and 6) is much more specific. We give a result about gauge/gravity duality that shows its relation to gauge symmetries (in the physical sense of symmetry transformations that are spacetime-dependent) to be subtler than you might expect. For gauge theories, you might expect that the duality bijections relate only gauge-invariant quantities and states, in the sense that gauge symmetries in one theory will be unrelated to any symmetries in the other theory. This may be so in general; and indeed, it is suggested by discussions of Polchinski and Horowitz. But we show that in gauge/gravity duality, each of a certain class of gauge symmetries in the gravity/bulk theory, viz. diffeomorphisms, is related by the duality to a position-dependent symmetry of the gauge/boundary theory.
We argue that CP is a gauge symmetry in string theory. As a consequence, CP cannot be explicitly broken either perturbatively or non-pertubatively; there can be no non-perturbative CP-violating parameters. String theory is thus an example of a theory where all $theta$ angles arise due to spontaneous CP violation, and are in principle calculable.