131 research outputs found
Search for charginos in e+e- interactions at sqrt(s) = 189 GeV
An update of the searches for charginos and gravitinos is presented, based on
a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector
in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was
found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a
centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by
combining the chargino searches with neutralino searches at the Z resonance
implies a limit on the mass of the lightest neutralino which, for a heavy
sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure
Hadronization properties of b quarks compared to light quarks in e+e- -> q qbar from 183 to 200 GeV
The DELPHI detector at LEP has collected 54 pb^{-1} of data at a
centre-of-mass energy around 183 GeV during 1997, 158 pb^{-1} around 189 GeV
during 1998, and 187 pb^{-1} between 192 and 200 GeV during 1999. These data
were used to measure the average charged particle multiplicity in e+e- -> b
bbar events, _{bb}, and the difference delta_{bl} between _{bb} and the
multiplicity, _{ll}, in generic light quark (u,d,s) events: delta_{bl}(183
GeV) = 4.55 +/- 1.31 (stat) +/- 0.73 (syst) delta_{bl}(189 GeV) = 4.43 +/- 0.85
(stat) +/- 0.61 (syst) delta_{bl}(200 GeV) = 3.39 +/- 0.89 (stat) +/- 1.01
(syst). This result is consistent with QCD predictions, while it is
inconsistent with calculations assuming that the multiplicity accompanying the
decay of a heavy quark is independent of the mass of the quark itself.Comment: 13 pages, 2 figure
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)
Comparative palatability among eggs of mass-spawning corals
The eggs and larvae of mass-spawning reef corals are seasonally abundant and highly nutritious and are therefore a potentially important food source for planktivorous fishes. While there arc several reports of fish feeding on coral propagules, it is not known whether propagules of different coral species are equally palatable. Here we report that the planktivorous fish Pomacentrus moluccensis readily consumed, and did not distinguish between, food pellets made from eggs of Acropora millepora and A. humilis. In contrast, pellets made from eggs of Pachyseris speciosa were often tasted but then rejected. Pomacemrus moluccensis consistently selected pellets made from eggs of the Acropora species over pellets made from eggs of P. speciosa. These preliminary findings suggest that not all coral propagules are equally palatable. Consequently rates of larval mortality resulting from fish predation may vary greatly among different coral species
Is the Individual Market More Than a Bridge Market? An Analysis of Disenrollment Decisions
Differential impacts of public health insurance expansions at the local level
Health insurance, Labor markets, Unemployment, Medicaid, SCHIP, I1, H7,
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