Three-Neutrino MSW Effect and the Lehmann Mass Matrix

Recent work on analytical solutions to the MSW equations for three neutrino flavours is reviewed, with emphasis on the exponential density. Application to a particular mass matrix, proposed by Lehmann, Newton and Wu, is also discussed. Within this model, the experimental data allow a determination of the three neutrino masses. They are found to be 0.002-0.004, 0.01 and 0.05 eV.Comment: 6 pages, LaTeX, 1 figure. Invited talk given at the conference "Beyond the Desert 2002", 2-7 June 2002, Oulu, Finland, to be published in the proceeding

CP Investigations in the Higgs Sector

In a more general electroweak theory, there could be Higgs particles that are odd under $CP$. When such particles decay via vector bosons to two fermion-antifermion pairs, the momenta of those will be correlated in a way which is determined by the $CP$ of the particle. Similarly, in the Bjorken process correlations among momenta of the initial electron and final-state fermions are sensitive to the $CP$ quantum number. Monte Carlo data on the expected efficiency demonstrate that it should be possible to verify the scalar character of an intermediate-mass Standard Model Higgs boson after three years of data taking at a future linear collider. This is most likely not possible at LEP2. Signals of possible presence of $CP$ violation in the Higgs sector are briefly discussed.Comment: 12 pages, LaTex2e, plus 7 uuencoded figures. Invited paper, Third Tallinn Symposium on Neutrino Physics, Lohusalu, Estonia, October 7-11, 199

Maximal CP nonconservation in the Two-Higgs-Doublet Model

We study the simplest Two-Higgs-Doublet Model that allows for CP nonconservation, where it can be parametrized by only one parameter in the Higgs potential. Different concepts of maximal CP-nonconservation in the gauge-Higgs and the quark-Higgs (Yukawa) sectors are compared. Maximal CP nonconservation in the gauge-Higgs sector does normally not lead to maximal CP nonconservation in the Yukawa sector, and vice versa.Comment: 22 pages, including figures. Invited talk given at the Cracow Epiphany conference on heavy flavours, 3 - 6 January 2003, Cracow, Poland, a shortened version to be published in Acta Physica Polonica, July 200

Signals of CPCP violation in Higgs decay

We consider an extension of the Standard Model where some Higgs particle is not an eigenstate of $CP$, and discuss the possibility of extracting signals of the resulting $CP$ violation. In the case of Higgs decay to four fermions we study correlations among momenta of the final-state fermions. We discuss observables which may demonstrate presence of $CP$ violation and identify a phase shift $\delta$, which is a measure of the strength of $CP$ violation in the Higgs-vector-vector coupling, and which can be measured directly in the decay distribution. In addition to these angular correlations, we consider correlations between energy differences. The former correlations include some recently reported results, whereas the latter ones appear to provide a much better probe for revealing $CP$ violation.Comment: 11 pages (5 figures in Postscript appended as uuencoded tar-compressed file), LATEX (full postscript version available by anonymous ftp at node VSFYS1.FI.UIB.NO in subdirectory OSLAND, file BERGEN94-06.PS), Bergen Scientific/Technical Report No. 1994-0

Light-Gluino Production at LEP

If gluinos are light, they will be produced in electron-positron annihilation at LEP, not only by radiation in pairs off quarks and antiquarks, but also without accompanying quark and antiquark jets. We here discuss the latter process, pair production of gluinos, in a model with soft supersymmetry breaking, allowing for mixing between the squarks. In much of the parameter space of the Minimal Supersymmetric Model (MSSM) the cross section corresponds to a $Z$ branching ratio above $10^{-5}$, even up to $10^{-4}$. A non-observation of gluinos at this level restricts the allowed MSSM parameter space.Comment: 8 pages, LaTex 2.09, 4 figures, uuencoded ps files Full ps file available via anonymous ftp at ftp://vsfys1.fi.uib.no/anonymous/kileng/NORDITA_9460.ps (Figures now tar-compressed according to party line.

More Series related to the Euler Series

We present results for infinite series appearing in Feynman diagram calculations, many of which are similar to the Euler series. These include both one-, two- and three-dimensional series. All these series can be expressed in terms of zeta(2) and zeta(3).Comment: 17 pages, LaTeX, uses elsart.cl

Perturbative Aspects of q-Deformed Dynamics

Within the framework of the q-deformed Heisenberg algebra a dynamical equation of q-deformed quantum mechanics is discussed. The perturbative aspects of the q-deformed Schr\"odinger equation are analyzed. General representations of the additional momentum-dependent interaction originating from the q-deformed effects are presented in two approaches. As examples, such additional interactions related to the harmonic-oscillator potential and the Morse potential are demonstrated.Comment: 10 pages, LaTeX, including 1 figur

Some infinite series related to Feynman diagrams

Results are presented for some infinite series appearing in Feynman diagram calculations, many of which are similar to the Euler series. These include both one-, two- and three-dimensional series. The sums of these series can be evaluated with the help of various integral representations for hypergeometric functions, and expressed in terms of $\zeta(2)$, $\zeta(3)$, the Catalan constant $G$ and ${\rm Cl}_2(\pi/3)$ where ${\rm Cl}_2(\theta)$ is Clausen's function.Comment: 10 pages, LaTeX, 2 figures; presented at ICCAM-200

Dyon mass bounds from electric dipole moments

Dyon loops give a contribution to the matrix element for light-by-light scattering that violates parity and time-reversal symmetry. This effect induces an electric dipole moment for the electron, of order $M^{-2}$, where $M$ is the dyon mass. The current limit on the electric dipole moment of the electron yields the lower mass bound M>{\cal O}(1)~\mbox{TeV}.Comment: LaTeX + 1 figure as uuencoded PostScript fil

Roy Glauber and Asymptotic Diffraction Theory

This is a review of Glauber's asymptotic diffraction theory, in which diffractive scattering is described in terms of interference between semiclassical amplitudes, resulting from a stationary-phase approximation. Typically two such amplitudes are sufficient to accurately describe elastic scattering, but the stationary points are located at complex values of the impact parameter. Their separation controls the interference pattern, and their offsets from the real axis determine the overall fall-off with momentum transfer. Asymptotically, at large momentum transfers, the stationary points move towards singularities of the profile function. I also include some reminiscences from our collaboration.Comment: 12 pages, contribution to SciPost Physics Proceedings: EFB 24. v2: minor change