59 research outputs found
Neutron charge form factor at large
The neutron charge form factor is determined from an analysis of
the deuteron quadrupole form factor data. Recent calculations, based
on a variety of different model interactions and currents, indicate that the
contributions associated with the uncertain two-body operators of shorter range
are relatively small for , even at large momentum transfer . Hence,
can be extracted from at large without undue
systematic uncertainties from theory.Comment: 8 pages, 3 figure
Travelers With Cutaneous Leishmaniasis Cured Without Systemic Therapy
Guidelines recommend wound care and/or local therapy as first-line treatment for cutaneous leishmaniasis. An analysis of a referral treatment program in 135 travelers showed that this approach was feasible in 62% of patients, with positive outcome in 83% of evaluable patient
Photochemical Degradation of Poly(ethylene terephthalate)-Modified Copolymer
The photolysis and the photooxidation of poly(ethylene terephthalate, PET)-modified copolymer have been investigated. The copolymer (COP) that results from the polycondensation of terephthalic acid, ethyleneglycol and 1,4-cyclohexanedimethanol was studied and a comparison with the behaviour of PET was made. Under vacuum irradiation at lambda \u3e 300 nm, the pure photolytic processes involve Norrish type I and II reactions. The formation of the hydroxylated and carbonyl containing photolytic products, which involves hydrogen abstraction from the polymeric backbone, is enhanced in the COP: this result is related to the labile hydrogen atom on the tertiary carbon atom of the cyclohexane units. The pure photolytic processes, in the presence of oxygen, induces oxidation of the aliphatic sequences under polychromatic (lambda \u3e 300 nm) and monochromatic irradiations (254 and 365 nm). The tertiary carbon atoms of the cyclohexane units are shown to be more oxidizable than the methylene groups in the alpha-position of the eater groups. The decomposition of the hydroperoxides so formed leads to the formation of acetic and formic acids that can migrate out of the film; it also generates hydroxy radicals that is one path leading to the ortho-hydroxylation of aromatic rings which gives fluorescence emission to the photooxidised films. The penetration of polychromatic light in the COP sample limits the degradation to the 100 mu m top layer. In this superficial layer, chain scission occurs to a large extent as revealed by the identification of terephthalic acid. (C) 2000 Elsevier Science Ltd. All rights reserved
Backward production in reaction at 9 and 12 GeV/c
The authors have analyzed backward meson production in the reaction pi /sup -/p to p/sub f/ pi /sup +/ pi /sup -/ pi /sup -/ at 9 GeV/c and 12 GeV/c incident pi /sup -/ momenta, from an experiment performed at the CERN Omega Spectrometer using a fast proton (p/sub f/) trigger device. They find strong production of quasi-two-body processes N* rho and N*f with a production mechanism consistent with u-channel nucleon exchange. At a lower level, N* pi processes with a 3-body baryon decay through Delta (1232) pi are observed. In the (3 pi )/sup -/ system, evidence is found for A/sub 1//sup -/ and clear A/sub 2//sup -/ backward production with similar cross sections ( approximately 0.5 mu b). (16 refs)
Backward omega /sup 0/ and eta /sup 0/ production in pi p interactions at 9 and 12 GeV/c
The backward production of omega /sup 0/ mesons in the u-channel I/sub u/=/sup 1///sub 2/ exchange reaction pi /sup -/p to N/sup 0/ (1680) omega /sup 0/ has been studied at 9 GeV/c and 12 GeV/c incident momenta. The data comes from an experiment performed at the CERN Omega Spectrometer using a fast proton trigger device. The backward production of the eta /sup 0/ meson has also been observed and the coupling constant ratio g/sub eta NN//g/sub pi NN/ has been estimated. (21 refs)
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