3,854 research outputs found
Ground state charmed meson spectra for N_f=2+1+1
We present a preliminary study of the charmed meson spectra using the
electrically neutral subset of the new Budapest-Marseille-Wuppertal N_f=2+1+1
gauge configurations that utilise the 3-HEX smeared clover action. The analysis
is performed with a focus on the hyperfine splitting.Comment: 7 pages, 5 figures; presentation given at the 33rd International
Symposium on Lattice Field Theory (Lattice 2015), 14 - 18 July 2015, Kobe,
Japa
Higher-order relativistic corrections to gluon fragmentation into spin-triplet S-wave quarkonium
We compute the relative-order-v^4 contribution to gluon fragmentation into
quarkonium in the 3S1 color-singlet channel, using the nonrelativistic QCD
(NRQCD) factorization approach. The QCD fragmentation process contains infrared
divergences that produce single and double poles in epsilon in 4-2epsilon
dimensions. We devise subtractions that isolate the pole contributions, which
ultimately are absorbed into long-distance NRQCD matrix elements in the NRQCD
matching procedure. The matching procedure involves two-loop renormalizations
of the NRQCD operators. The subtractions are integrated over the phase space
analytically in 4-2epsilon dimensions, and the remainder is integrated over the
phase-space numerically. We find that the order-v^4 contribution is enhanced
relative to the order-v^0 contribution. However, the order-v^4 contribution is
not important numerically at the current level of precision of
quarkonium-hadroproduction phenomenology. We also estimate the contribution to
hadroproduction from gluon fragmentation into quarkonium in the 3PJ color-octet
channel and find that it is significant in comparison to the complete
next-to-leading-order-in-alpha_s contribution in that channel.Comment: 41 pages, 8 figures, 3 tables, minor corrections, version published
in JHE
Evaluation of enzyme immunoassays in the diagnosis of camel (Camelus dromedarius) trypanosomiasis:a preliminary investigation
Three enzyme immunoassays were used for the serodiagnosis of Trypanosoma evansi in camels in the Sudan in order to evaluate their ability to discriminate between infected and non-infected animals. Two assays were used for the detection of trypanosomal antibodies, one using specific anti-camel IgG conjugate and another using a non-specific Protein A conjugate. The third assay detected the presence of trypanosomal antigens using anti-T. evansi antibodies in a double antibody sandwich assay. Inspection of the frequency distribution of assay results suggested that the ELISA for circulating trypanosomal antibodies using specific antisera and the ELISA for circulating antigens can distinguish between non-infected camels and infected camels exhibiting patent infections or not. The ELISA using Protein A conjugate to bind non-specifically to camel immunoglobulin did not appear to discriminate between infected and non-infected animals
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