Search For Exotic Particles Research Articles

SEARCHES FOR EXOTIC PARTICLES IN e+ e- COLLISIONS WITH THE DELPHI DETECTOR

Results of searches for exotic particles by the DELPHI collaboration at CERN are prented. Highlights from the searches for Flavor Changing Neutral Currents, Technicolor, Fermiophobic Higgs and Compositeness, in the LEP 2 data are shown. No evidence for new physics was found and the excluded regions of the parameter space for each model are presented.

THE SEARCH FOR STABLE, MASSIVE, ELEMENTARY PARTICLES

In this paper we review the experimental and observational searches for stable, massive, elementary particles other than the electron and proton. The particles may be neutral, may have unit charge or may have fractional charge. They may interact through the strong, electromagnetic, weak or gravitational forces or through some unknown force. The purpose of this review is to provide a guide for future searches — what is known, what is not known, and what appear to be the most fruitful areas for new searches. A variety of experimental and observational methods such as accelerator experiments, cosmic ray studies, searches for exotic particles in bulk matter and searches using astrophysical observations is included in this review.

Underground experiments for cosmic ray physics: results and future projects

A review is made of the main results obtained by large underground detectors on cosmic ray physics, neutrino physics and astrophysics and searches for exotic particles. Future projects and their objectives are also briefly reviewed.

Open problems in the physics of charmonium and QCD exotics

Recent developments in charmonium physics are presented in order to highlight the still open problems. The current status of searches for exotic particles predicted by QCD, dibaryons, hybrids, and glueballs is reviewed.

Precise measurements of e+e- annihilation at rest into four photons and the search for exotic particles.

We measured the branching ratio R of ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}4\ensuremath{\gamma} with respect to ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}2\ensuremath{\gamma} as [1.48\ifmmode\pm\else\textpm\fi{}0.13(statistical)\ifmmode\pm\else\textpm\fi{}0.12(systemic)]\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}6}$. The upper limits of the branching ratios for the exotic particles are obtained to be around 3\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}7}$.

CUSB-II: a high precision electromagnetic spectrometer

Abstract The design, construction and performance of a very compact precision electromagnetic spectrometer is described. The CUSB-II detector has been used to study ϒ spectroscopy, search for exotic particles and measure properties of the B and B ∗ mesons at the Cornell Electron Storage Ring.

Accelerator Mass Spectrometry for Measurement of Long-Lived Radioisotopes

Particle accelerators, such as those built for research in nuclear physics, can also be used together with magnetic and electrostatic mass analyzers to measure rare isotopes at very low abundance ratios. All molecular ions can be eliminated when accelerated to energies of millions of electron volts. Some atomic isobars can be eliminated with the use of negative ions; others can be separated at high energies by measuring their rate of energy loss in a detector. The long-lived radioisotopes (10)Be, (14)C,(26)A1, 36Cl, and (129)1 can now be measured in small natural samples having isotopic abundances in the range 10(-12) to 10(- 5) and as few as 10(5) atoms. In the past few years, research applications of accelerator mass spectrometry have been concentrated in the earth sciences (climatology, cosmochemistry, environmental chemistry, geochronology, glaciology, hydrology, igneous petrogenesis, minerals exploration, sedimentology, and volcanology), in anthropology and archeology (radiocarbon dating), and in physics (searches for exotic particles and measurement of halflives). In addition, accelerator mass spectrometry may become an important tool for the materials and biological sciences.