6,986 research outputs found
Single-spin asymmetries in the leptoproduction of transversely polarized hyperons
We analyze single-spin asymmetries (SSAs) in the leptoproduction of
transversely polarized hyperons within the collinear twist-3
formalism. We calculate both the distribution and fragmentation terms in two
different gauges (lightcone and Feynman) and show that the results are
identical. This is the first time that the fragmentation piece has been
analyzed for transversely polarized hadron production within the collinear
twist-3 framework. In lightcone gauge we use the same techniques that were
employed in computing the analogous piece in , which
has become an important part to that reaction. With this in mind, we also
verify the gauge invariance of the formulas for the transverse SSA in the
leptoproduction of pions.Comment: 12 pages, 1 figure, reference added, version to appear in Phys. Lett.
Longitudinal-transverse double-spin asymmetries in single-inclusive leptoproduction of hadrons
We analyze the longitudinal-transverse double-spin asymmetry in
lepton-nucleon collisions where a single hadron is detected in the final state,
i.e., . This is a subleading-twist
observable in collinear factorization, and we look at twist-3 effects in both
the transversely polarized nucleon and the unpolarized outgoing hadron. Results
are anticipated for this asymmetry from both HERMES and Jefferson Lab Hall A,
and it could be measured as well at COMPASS and a future Electron-Ion Collider.
We also perform a numerical study of the distribution term, which, when
compared to upcoming experimental results, could allow one to learn about the
"worm-gear"-type function as well as assess the role of
quark-gluon-quark correlations in the initial-state nucleon and twist-3 effects
in the fragmenting unpolarized hadron.Comment: 14 pages, 7 figures, minor changes to the text, version to appear in
Phys. Lett.
Development of a 1000V, 200A, low-loss, fast-switching, gate-assisted turn-off thyristor
The results of a program to develop a fast high power thyristor that can operate in switching circuits at frequencies of 10 to 20 kHz with very low power loss are given. Feasibility was demonstrated for a thyristor that blocks 1000V forward and reverse, conducts 200A, turns on in little more than 2 more microseconds with only 2A of gate drive, turns off in 3 microseconds with 2A of gate assist current and has an energy dissipation of only 12 mJ per pulse for a 20 microsecond half sine wave 200A pulse. Data were generated that clearly showed the tradeoffs that can be made between the turn off time and forward drop. The understanding of this relationship is necessary in the selection of deliverable thyristors with turn off times up to 7 microseconds to give improved efficiency in a series resonant dc to dc inverter application
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