Modern Physics Letters A

We investigate the time-of-night variation of solar neutrino rate which will be of relevance to super-Kamioka and Sudbury neutrino detectors in the framework of oscillations among the three flavors. An analytical method of computing the regeneration in the earth is presented. If day–night effect is seen, we show how the study of the time-of-night variation will allow the determination of the neutrino parameters.

Supersymmetry is perhaps most effectively probed at the Tevatron through production and decay of weak gauginos. Most of the analyses of weak gaugino observables require electrons or muons in the final state. However it is possible that the gauginos will decay primarily to τ leptons, thus complicating the search for supersymmetry. The motivating reasons for high τ multiplicity final states are discussed in three approaches to supersymmetry model building: minimal supergravity, minimal gauge mediated supersymmetry, and more minimal supersymmetry. The concept of "e/μ/τ candidate" is introduced, and an observable with three e/μ/τ candidates is defined in analog to the trilepton observable. The maximum mass reach for supersymmetry is then estimated when gaugino decays to τ leptons have full branching fraction.

We confirm the non-integrability of the multi-deformed Ising model — an already expected result. After deforming with the energy operator ϕ_1,3, we use the Majorana free fermionic representation for the massive theory to show that, besides the trivial one, no local integrals of motion can be built in the theory arising from perturbing with both energy and spin operators.

A model-independent analysis is made using the LEP and SLD data on Z decays available at the end of 1996. The effective weak coupling constants of leptons, c quarks and b quarks are extracted. Except for the right-handed b-quark coupling, they all agree with the predictions of the standard electroweak model for m_t=180 GeV and m_H=100 GeV. The right-handed b-quark coupling is found to be 42% and 3.2 standard deviations above the standard model prediction.

We suggest that the topological susceptibility in gluodynamics can be found in terms of the gluon condensate using renormalizability and heavy fermion representation of the anomaly. Analogous relations can also be obtained for other zero-momentum correlation functions involving the topological density operator. Using these relations, we find the θ dependence of the condensates <GG>, and of the partition function for small θ and an arbitrary number of colors.

A three-dimensional non-Abelian gauge theory was proposed by Jackiw and Pi to create mass for the gauge fields. However, the quadratic action obtained by switching off the non-Abelian interactions possesses more gauge symmetries than the original one, causing some difficulties in quantization. Jackiw and Pi proposed another action by introducing new fields, whose gauge symmetries are consistent with the quadratic part. It is shown that all of these theories have the same number of physical degrees of freedom in the Hamiltonian framework. Hence, as far as the physical states are considered, there is no inconsistency. Nevertheless, perturbation expansion is still problematic. To rectify this we propose to modify one of the constraints of the non-Abelian theory without altering its canonical Hamiltonian nor the number of physical states.

We obtain extremal stationary solutions that generalize the Israel–Wilson–Perjés class for the low-energy limit of heterotic string theory with n≥3U(1) gauge fields toroidally compactified from five to three dimensions. A dyonic solution is obtained using the matrix Ernst potential (MEP) formulation and expressed in terms of a single real (3×3)-matrix harmonic function. By studying the asymptotic behavior of the field configurations, we define the physical charges of the field system. The extremality condition makes the charges saturate the Bogomol'nyi–Prasad–Sommmerfield (BPS) bound.

Depending on their masses, supersymmetric particles can affect various measurements in Z decay. Among these are the total width (or consequent extracted value of α_s), enhancement or suppression of various flavors, and left–right and forward–backward asymmetries. The latter depend on squark mass splittings and are, therefore, a possible test of the supergravity related predictions. We calculate leading order corrections for these quantities considering in particular the case of light photino and gluino where the SUSY effects are enhanced. In this limit the effect on α_s is appreciable, the effect on R_b is small, and the effect on the asymmetries is extremely small.