Vladimir B. Flyagin

A new upper limit for the branching ratio of the decay K0S → e+e−

Abstract A new value of the upper limit for the branching ratio of the decay of K 0 S into e + e − has been experimentally obtained using a lead glass detector. The value is BR (K 0 S → e + e − ) −4 (90% CL).

Some top-quark properties measured in \(p\bar p\) collisions using CDF detector at √s = 1.96 TeV (Review)

This review considers important properties of the top-quark. The top-quark decays before hadronization, and the spin information is directly transferred to the decay products. Therefore the structure of the weak interaction is investigated by measuring the helicity fractions, f, of the W boson—the top-quark decay product. Other investigations: search for the presence of V+A interaction, search for exotic top-quark charge — 4/3 and for (tbar t) — resonances—all of them, so far, were not found in the experiments — testifies against of going out of the Standard Model.

The top quark, others new phenomena observed at the CDF in {ie359-1} collisions at √s = 1.96 TeV (Review)

Upgraded Tevatron luminosity in Run-II (started 2001) has opened a new level of modern heavy-quark studies compared to that one of Run-I. Now top event samples contain hundreds of event statistics for investigation. This review mainly covers the mass measurements of the top quark produced at √s = 1.96 TeV in {ie359-2} collisions at the Collider Detector of Fermilab with the integrated luminosity samples up to 1 fb−1. As an example of the top quark mass measurements we consider so-called Matrix Element method in “lepton + jets” and “dilepton” channels of the top-quark decay. The CDF top quark mass obtained in lepton +jets mode is the world most precise single measurement of this important physics parameter. The review summarizes the essential results of the CDF top-quark mass measurement achieved and published for the recent 2003–2008 period. We consider also b-quark baryon discoveries like Σb, Σb*, Θb as well as first observation of {ie359-3} oscillations. Let us mention here that a CDF/JINR-group created significant contribution to the new CDF complex and physics investigation.

BUBBLE CHAMBER OPERATION IN THE REGIME OF AUTO-OSCILLATIONS

The possibility of constructing a high-efficiency bubble chamber is considered. The principle of operation depends on the production of pressure auto-oscillation conditions in the working fluid. A one-meter propane bubble chamber with a minimum air pressure stabilizer was used to study conditions for exciting and keeping up undamped oscillations in the chamber and conditions for bubble recompression. (A.G.W.)