Color Transparency Effects in Electron Deuteron Interactions at Intermediate Q^2

High momentum transfer electrodisintegration of polarized and unpolarized deuterium targets, $d(e,e'p)n$ is studied. We show that the importance of final state interactions-FSI, occuring when a knocked out nucleon interacts with the other nucleon, depends strongly on the momentum of the spectator nucleon. In particular, these FSI occur when the essential contributions to the scattering amplitude arise from internucleon distances $\sim 1.5~fm$. But the absorption of the high momentum $\gamma^*$ may produce a point like configuration, which evolves with time. In this case, the final state interactions probe the point like configuration at the early stage of its evolution. The result is that significant color transparency effects, which can either enhance or suppress computed cross sections, are predicted to occur for $\sim 4 GeV^2 \ge Q^2\leq~10~(GeV/c)^2$.Comment: 37 pages LaTex, 12 uuencoded PostScript Figures as separate file, to be published in Z.Phys.

Non linear equation of state and effective phantom divide in brane models

Here, DGP model of brane-gravity is analyzed and compared with the standard general relativity and Randall-Sundrum cases using non-linear equation of state. Phantom fluid is known to violate the weak energy condition. In this paper, it is found that this characteristic of phantom energy is affected drastically by the negative brane-tension $\lambda$ of the RS-II model. It is found that in DGP model strong energy condition(SEC) is always violated and the universe accelerates only where as in RS-II model even SEC is not violated for $1 < \rho/\lambda < 2$ and the universe decelerates

Limits on the production of scalar leptoquarks from Z (0) decays at LEP

A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)

Stock Price and Management Changes: The Case of REITs

This paper examines the relationship between a Real Estate Investment Trust's (REIT's) stock returns and top management changes. The results indicate an inverse relationship between the probability of a management change and a REIT's recent stock price performance. This is consistent with internal monitoring of management activities by the board of directors, other top managers, or large block shareholders. Copyright American Real Estate and Urban Economics Association.

Evidence for B(s)0 meson production in Z0 decays

Seven unambiguous events out of a sample of 270 000 Z0 decays, contain in the same jet a Ds meson and a muon at large transverse momentum relative to the jet axis. These events are direct evidence for Bs 0 meson production in hadronic Z0 decays. The production rate of these events, relative to all hadronic Z0 decays is (18 ± 8) × 10-5, this number including the relevant branching fractions of the Bs 0 and Ds. The value of the Bs 0 meson lifetime relative to the average B meson lifetime is measured to be 0.8 ± 0.4.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Measurement of the B0 - anti-B0 mixing using the average electric charge of hadron jets in Z0 decays

From the data recorded with the DELPHI detector at LEP in the years 1991–1992, 46497 events were selected having a high-momentum muon in hadron jets. A fit to the average electric charge sum of the jets recoiling against a b-quark jet tagged by a high-PT muon results in an average mixing parameter of View the MathML source