Detection of Neutral MSSM Higgs Bosons at LEP-II and NLC

We study the possibility of detecting the neutral Higgs bosons predicted in the Minimal Supersymmetric Standard Model (h0, H0, A0), with the reactions e+ e- --> b b h0 (H0, A0), using the helicity formalism. We analyze the region of parameter space (m_A0-tan beta) where h0(H0, A0) could be detected in the limit when tan beta is large. The numerical computation is done for the energy which is expected to be available at LEP-II (sqrt{s} = 200 GeV) and for a possible Next Linear e+ e- Collider (sqrt{s}=500 GeV).Comment: To be published in Phys.Rev.

Signatures for Majorana neutrinos in e−γe^- \gamma collider

We study the possibilities to detect Majorana neutrinos in $e^- \gamma$ colliders for different center of mass energies. We study the $W^- W^- l_j^{+}(l_j^+\equiv e^+ ,\mu^+ ,\tau^+)$ final state which are, due to leptonic number violation, a clear signature for intermediate Majorana neutrino contribution. Such a signal (final lepton have the opposite charge of the initial lepton) is not possible if the heavy neutrinos are Dirac particles. In our calculation we use the helicity formalism to obtain analytic expressions for the amplitude and we have considered that the intermediate neutrinos can be either on shell or off shell. Finally we present our results for the total cross-section and for the angular distribution of the final lepton. We also include a discussion on the expected events number as a function of the input parameters.Comment: Latex file with 12 pages and 6 figures. Submited to Phys. Rev.

Neodymium-complex-doped steady-state polymer waveguide lasers

Channel waveguides based on a polymer, 6-fluorinated-dianhydride/epoxy, which is actively doped with a rare-earth-ion-doped complex, Nd(thenoyltrifluoroacetone)3 1,10-phenanthroline, have been fabricated. Luminescence and loss spectra of the channel waveguides have been experimentally investigated. By optimization of the fabrication procedure of both, host material and optical structure, steady-state laser emission has been demonstrated from a channel waveguide near 1060 nm, which provides up to 440 µW of output power from the waveguide structures developed

DNA Separation and Fluorescence Monitoring by Integrated Waveguides in an Optofluidic Chip

We report on the monolithic integration of optical waveguides and microfluidics in a fused-silica lab-on-a-chip. Labeled biomolecules such as double-stranded DNA are flown and separated in the microfluidic channel by capillary electrophoresis and their fluorescent labels are excited by a continuous-wave laser beam through femtosecondlaser-written integrated waveguides. In this context, desirable features such as high spatial resolution (~12 μm), and a low limit of detection (~ 6 nano-molar) have been experimentally demonstrated. The proof of concept is being extended to real-world diagnostic samples for on-chip diagnosis of genetic diseases, e.g. breast cancer