257 research outputs found
Spin content of constituent quarks and one-spin asymmetries in inclusive processes
We consider mechanism for one-spin asymmetries observed in inclusive hadron
production. The main role belongs to the orbital angular momentum of the
quark-antiquark cloud in the internal structure of constituent quarks. We argue
that the origin of the asymmetries in pion production is a result of retaining
of this internal angular orbital momentum by the perturbative phase of QCD
under transition from the non-perturbative phase. The non-perturbative hadron
structure is based on the results of chiral quark models. PACS number(s):
11.30.Qc, 12.40.Pp, 13.75.Ni, 13.88.+eComment: 21 pages LaTeX + 8 figures (not included
Search for Direct CP Violation in Non-Leptonic Decays of Charged and Hyperons
A search for direct CP violation in the non-leptonic decays of hyperons has
been performed. In comparing the product of the decay parameters,
, in terms of an asymmetry parameter,
, between hyperons and anti-hyperons in the charged and decay sequence, we found no evidence of
direct CP violations. The parameter was measured to be .Comment: Submitted for publication; RevTex, 13 pages, 4 figure
Hyperon Polarization in the Constituent Quark Model
We consider mechanism for hyperon polarization in inclusive production. The
main role belongs to the orbital angular momentum and polarization of the
strange quark-antiquark pairs in the internal structure of the constituent
quarks. We consider a nucleon as a core consisting of the constituent quarks
embedded into quark condensate. The nonperturbative hadron structure is based
on the results of chiral quark models.Comment: 14 pages, LaTeX, 2 Figures, References adde
Preliminary results from E756 on the Ξ− and Ω− magnetic moments
We have used the spin precession technique to measure the Ξ− and Ω− magnetic moments. The preliminary results are μ(Ξ−)=−0.64±0.02 nuclear magnetons and μ(Ω−)=−2.0±0.2 nuclear magnetons where the error for both measurements is statistical. The polarization of Ξ−’s produced at 2.5 mr by 800 GeV protons on a Be target was 11% while the polarization of Ω−’s was consistent with zero. Polarized Ξ−’s and Ω−’s were produced using spin transfer from a polarized neutral hyperon beam. The Ω− polarization at 325 GeV/c was 6.5%.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87375/2/374_1.pd
Polarization and spin transfer of Ω− and Ξ− hyperons at 800 GeV
Fermilab experiment E756 has measured the polarization of W− hyperons produced by 800 GeV protons to be small compared to that of Ξ− hyperons. When produced by a neutral beam containing polarized Λ and Ξ0 hyperons, both the Ω− and the Ξ− have a significant polarization indicating a large spin transfer at high energies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87380/2/80_1.pd
Measurement of Decay Parameters for Decay
Based on 1.35 million polarized events, we measure the parameter
to be for
decay. New results for the parameters
and are also presented. Assuming that the
CP-violating phase-shift difference is negligible, we deduce the strong
phase-shift difference between the P-wave and S-wave amplitudes of the
final state to be . This strong phase-shift difference reduces the theoretical
uncertainty in estimating the level of CP violation in -hyperon decay.Comment: To be published in Physical Review Letter
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