0000000001324142
AUTHOR
Ramón Cases Ruiz
First evidence of hard scattering processes in single tagged gamma-gamma-collisions
For the first time, multihadronic production from single tagged gammagamma collisions has been studied, where one of the scattered leptons was tagged at very low virtual photon absolute mass squared ( = 0.06GeV/(c2))2 ). Data collected during 1991 and 1992 in the DELPHI experiment at LEP are shown to agree well with predictions which included the non-perturbative vector meson dominance model in which the interacting photons are assumed to have converted into a vector meson (rho, omega or pi), a quark-parton model which describes direct photon interactions and a QCD-based model which considers the photon to have quark and gluon structure functions. Five different parametrizations of these st…
Search for pair-produced heavy scalars in Z° decays
A search for charged Higgs bosons decaying into quarks is described, based on statistics of around 1.7 million hadronic Z0 decays detected in DELPHI. Despite the very high background from standard hadronic decays of the Z0, masses in the range up to 43.5 GeV/c2 are excluded at the 95% con dence level. After combination with a search for leptonic decays, this mass limit is extended to cover all branching ratios. A similar analysis sets new limits on the possible production of any pair-produced heavy scalar decaying into a pair of jets, such as neutral Higgs bosons in a two doublet scheme and diquarks.
A Study of radiactive muon-pair events at Z° energies and limits on an additional Z' gauge boson
An analysis is reported on the channele + e −→μ+μ−(nγ), n=1,2..., using data taken with the DELPHI detector at LEP from 1990 to 1992. Differential cross sections of the radiative photons as a function of photon energy and of the angle between the photon and the muon are presented. No significant deviations from expectations are observed. The data are also used to extract the muon-pair cross section and asymmetry below the Z0 peak by using those events with relatively hard initial state radiative photon(s). The measured cross section and asymmetry show no significant deviation from the Standard Model expectations. These results together with the DELPHI cross section and asymmetry measurement…
Measurement of time-dependent b-d(0) (b)over-bar-d(0) mixing
The time dependent mixing of View the MathML source mesons has been observed by using the correlations between the charge of D∗ mesons and the weighted mean charge of particles in each hemisphere. From a reconstructed D∗± sample corresponding to about 1.7 million hadronic Z0 decays, the mass difference between the two Bd0 mass eigenstates has been measured to be View the MathML source or, converting into eV/c2: Δm = [3.29 ± 0.79 (stat) ± 0.39 (syst.)] 10−4 eV/c2.
Demo 98. Péndulo electrostático
Objetivo: Detectar la presencia de cargas eléctricas con materiales sencillos.
Demo 87. Patrones ondulatorios de sonidos
Objetivo: Observar la forma de las ondas sonoras correspondientes a distintos instrumentos musicales. Analizar el espectro de frecuencias de dichos sonidos.