Looking for anomalous gamma-gamma-H and Z-gamma-H couplings at future linear collider

We consider the possibility of studying anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices through the process e-gamma--> e-H at future e-gamma linear colliders, with Sqrt(S)=500-1500 GeV. We make a model independent analysis based on SU(2)xU(1) invariant effective operators of dim=6 added to the standard model lagrangian. We consider a light Higgs boson (mostly decaying in bar(b)-b pairs), and include all the relevant backgrounds. Initial e-beam polarization effects are also analyzed. We find that the process e-gamma--> e-H provides an excellent opportunity to strongly constrain both the CP-even and the CP-odd anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices.Comment: LaTeX, 33 pages, 16 eps figures, extended section

Self field measurements by Hall sensors on the SeCRETS short sample CICC's subjected to cyclic load

An imbalance in the transport current among the strands of a Cable-in-Conduit conductors (CICC) can be associated with the change of their performance. In order to understand and improve the performance of CICC's, it is essential to study the current imbalance. This paper focuses on the study of the current imbalance in two short samples of the SeCRETS (Segregated Copper Ratio Experiment on Transient Stability) conductors subjected to a cyclic load in the SULTAN facility. The self field around the conductors was measured on four locations by 32 miniature Hall sensors for a reconstruction of the current distribution. The results of the self field measurements in the DC tests are presented and discussed

On the search for 50 GeV neutrinos

Using the computer code CompHEP we estimate the number of events and the background, at LEP II and TESLA, for the reaction $e^+ e^- \to N\bar{N}\gamma$, where $N$ is a hypothetical Dirac neutrino with mass of the order of 50 GeV.Comment: Standard LaTeX, 9 pages, 2 tables, 3 figure

Precision measurements, extra generations and heavy neutrino

The existence of extra chiral generations with all fermions heavier than $M_Z$ is strongly disfavored by the precision electroweak data. The exclusion of one additional generation of heavy fermions in SUSY extension of Standard Model is less forbidden if chargino and neutralino have low degenerate masses with $\Delta m \simeq 1$ GeV. However the data are fitted nicely even by a few extra generations, if one allows neutral leptons to have masses close to 50 GeV. Such heavy neutrino can be searched in the reaction $e^+ e^- \to N\bar{N}\gamma$ at LEP-200 with total final luminosity of $2600 pb^{-1}$.Comment: 5 pages, 6 figures, Proceedings ICHEP2000 Osaka conferenc

Bounds on anomalous gamma-gamma-H and Z-gamma-H couplings at future e-gamma linear colliders

We study the bounds on the anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices that can be obtained via the process e-gamma-->e H. We consider the representative case of an intermediate Higgs mass production of MH=120 GeV and for a center of mass energy of Sqrt{S}=500 GeV and Sqrt{S}=1500 GeV. We use a model independent analysis based on SU(2)xU(1) invariant operators of dimension 6 added to the Standard Model lagrangian. We find that this process provides an excelent way to put strong constraints both in the sector of CP-even and CP-odd anomalous couplings contribution to the gamma-gamma-H and Z-gamma-H vertices.Comment: LaTeX, 6 pages, To appear in the proceedings of the International Workshop on Linear Colliders, Sitges, Barcellona, Spain, April 28 - May 5, (1999

Anomalous gamma-gamma-H and Z-gamma-H couplings in the process e,gamma->e,H

The bounds on the anomalous contributions to the ggh and zgh vertices that can be obtained via the process eg->eh are discussed through a model independent analysis based on SU(2) X U(1) invariant operators of dim=6. A light Higgs boson with m_H ~ 120 GeV and center-of-mass energies of \sqrt{S}=500 GeV and \sqrt{S}=1500 GeV are assumed. The process eg->eh is shown to provide an excellent way to strongly constraint both the CP-even and CP-odd anomalous contributions in the ggH and ZgH couplings.Comment: 8 pages. To appear in the DESY report on "Physics Studies for a Future Linear Collider", DESY 123

Testing the ZγHZ\gamma H vertex at future linear colliders for intermediate Higgs masses

Higgs production in $e\gamma$ collisions, through the one-loop reaction $e\gamma\to eH$ at large $p_T$, can provide a precise determination of the $Z\gamma H$ vertex.Comment: 2 pages (standard LaTeX code); Contribution to the Proceedings of the Int. Europhysics Conference on High Energy Physics (Jerusalem, 19-26 August 1997

ZγHZ\gamma H Vertex Effects at Future Colliders

We show that the Higgs production in $e\gamma$ collisions, through the one-loop reaction $e\gamma\to eH$ at large transverse momentum, can provide a precise determination of the $Z\gamma H$ vertex. We concentrate on the analysis of signal rates vs background looking for strategies to improve the ratio $S/B$. Possible bounds on anomalous contributions to the $Z\gamma H$ vertex are derived.Comment: 5 pages (standard LaTeX code); Talk given at "Beyond the Standard Model V" Conference, April 29 - May 4 1997, Balholm (Norway); to be published in the Proceeding