142 research outputs found
Linguistics
Contains reports on three research projects.U. S. Air Force (Electronics Systems Division) under Contract AF 19(628)-2487Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 36-039-AMC-03200(E)National Science Foundation (Grant GK-835)National Institutes of Health (Grant 2 P01 MH-04737-06)National Aeronautics and Space Administration (Grant NsG-496
Linguistics
Contains reports on two research projects.National Institute of Mental Health (Grant 5 P01 MH-13390-05)National Institute of Mental Health (Grant 5 TO1 HD-00111-06
Complementary yet distinct roles for oestrogen receptor-α and oestrogen receptor-β in mouse mammary epithelial proliferation
New determinations of gamma-ray line intensities of the Ep = 550 keV and Ep = 1747 keV resonances of the 13-C(p,gamma)14-N reaction
Gamma-ray angular distributions for the resonances at Ep = 550 keV and 1747
keV of the radiative capture reaction 13-C(p,g)14-N have been measured, using
intense proton beams on isotopically pure 13-C targets. Relative intensities
for the strongest transitions were extracted with an accuracy of typically five
per cent, making these resonances new useful gamma-ray standards for efficiency
calibration in the energy range Egamma = 1.6 to 9 MeV.Comment: 17 pages, 6 figures, Nuclear Instruments and Methods, Sec. A,
accepte
Weak decays of 4He-Lambda
We measured the lifetime and the mesonic and non-mesonic decay rates of the
4He-Lambda hypernucleus. The hypernuclei were created using a 750 MeV/c
momentum K- beam on a liquid 4He target by the reaction 4He(K-,pi-)4He-Lambda.
The 4He-Lambda lifetime was directly measured using protons from Lambda p -> n
p non-mesonic decay (also referred to as proton-stimulated decay) and was found
to have a value of tau = 245 +/- 24 ps. The mesonic decay rates were determined
from the observed numbers of pi-'s and pi0's as Gamma_pi-/Gamma_tot = 0.270 +/-
0.024 and Gamma_pi0/Gamma_tot = 0.564 +/- 0.036, respectively, and the values
of the proton- and neutron-stimulated decay rates were extracted as
Gamma_p/Gamma_tot = 0.169 +/- 0.019 and Gamma_n/Gamma_tot <= 0.032 (95% CL),
respectively. The effects of final-state interactions and possible 3-body
Lambda N N decay contributions were studied in the context of a simple model of
nucleon-stimulated decay. Nucleon-nucleon coincidence events were observed and
were used in the determination of the non-mesonic branching fractions. The
implications of the results of this analysis were considered for the empirical
Delta I = 1/2 rule and the decay rates of the 4H-Lambda hypernucleus.Comment: 15 pages, 11 figures, published in PRC, revised content to match
published versio
Selective segregation of DNA strands persists in long label retaining mammary cells during pregnancy
Møllerov polarimetar za elektrone u dvorani A u JLabu
As part of the spin-physics program at Jefferson Laboratory (JLab), a Moller polarimeter was developed to measure the polarization of electron beam of energies 0.8 to 5.0 GeV. A unique signature for Moller scattering is obtained using a series of three quadrupole magnets which provide an angular selection, and a dipole magnet for energy analysis. The design, commissioning and the first results of the polarization measurements of this polarimeter will be presented as well as future plans to use its small scattering angle capabilities to investigate physics in very low Q2 regime.Kao dio programa istraživanja spinske fizike, u Jeffersonovom se laboratoriju sagradio Møllerov polarimetar radi mjerenja polarizacije elektrona energije 0,8 do 5,0 GeV. Jedinstven signal za Møllerovo raspršenje se postiže nizom od tri kvadrupolna magneta koji određuju kut, te dipolnim magnetom za analizu impulsa elektrona. Opis, preuzimanje i prva mjerenja s tim polarimetrom se izlažu, kao i planovi za buduću upotrebu mogućnosti sustava za mjerenja na malim kutovima raspršenja radi istraživanja fizike za vrlo male Q2
Toward a Consistent Description of the PNC Experiments in A=18-21 Nuclei
The experimental PNC results in F, F, Ne and the current
theoretical analysis show a discrepancy . If one interprets the small limit of
the experimentally extracted PNC matrix element for Ne as a destructive
interference between the isoscalar and the isovector contribution, then it is
difficult to understand why the isovector contribution in F is so small
while the isoscalar + isovector contribution in F is relatively large.
In order to understand the origin of this discrepancy a comparison of the
calculated PNC matrix elements was performed. It is shown that the F and
Ne matrix elements contain important contributions from 3
and 4 configuration and that the (0+1) calculations
give distorted results.Comment: REVTEX, 16 pages, 1 postscriptum figure uuencoded and appende
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