Strangeness in the Meson Cloud Model

I review progress in calculating strange quark and antiquark distributions of the nucleon using the meson cloud model. This progress parallels that of the meson cloud model, which is now a useful theoretical basis for understanding symmetry breaking in nucleon parton distribution functions. I examine the breaking of symmetries involving strange quarks and antiquarks, including quark - antiquark symmetry in the sea, SU(3) flavour symmetry and SU(6) spin-flavour symmetry.Comment: 6 pages, 4 figures. Talk given at workshop "Achievements and New Directions in Subatomic Physics: Workshop in honour of Tony Thomas' 60th birthday," CSSM, Adelaide, South Australia, 15 - 19 February 2010

Mapping properties for the Bargmann transform on modulation spaces

We investigate mapping properties for the Bargmann transform and prove that this transform is isometric and bijective from modulation spaces to convenient Banach spaces of analytic functions.Comment: Pre-version, 21 page

g1(x) and g2(x) in the Meson Cloud Model

We calculate the spin dependent structure functions g1(x) and g2(x) of the proton and neutron. Our calculation uses the meson cloud model of nucleon structure and includes the effects of kinematic terms which mix transverse and longitudinal spin components. We find small corrections to the nucleon structure functions, however these are significant for the neutron.Comment: 4 pages, contribution to DIS 05, Madison, Wisconsi

The flavour asymmetry of polarized anti-quarks in the nucleon

We present a study of the flavour asymmetry of polarized anti-quarks in the nucleon using the meson cloud model. We include contributions both from the vector mesons and the interference terms of pseudoscalar and vector mesons. Employing the bag model, we first give the polarized valence quark distribution of the $\rho$ meson and the interference distributions. Our calculations show that the interference effect mildly increases the prediction for \Delta \dbar(x)-\Delta \ubar(x) at intermediate $x$ region. We also discuss the contribution of `Pauli blocking' to the asymmetry.Comment: 22 pages, LaTex, 5 PS figures. Version to appear in Eur. Phys. J. C. An appendix is added for expressions for the helicity dependent fluctuation functions. An error in the programme for fluctuation function f_{(\pi\rho)\Delta /N} is corrected, which increases numerical results by about 10%. Unchanged conclusion

The quark - antiquark asymmetry of the strange sea of the nucleon

The strange sea of the proton is generally assumed to have quark - antiquark symmetry. However it has been known for some time that non-perturbative processes involving the meson cloud of the proton may break this symmetry. Recently this has been of interest as it affects the analysis of the so-called `NuTeV anomaly', and could explain the large discrepancy between the NuTeV measurement of $\sin^{2} \theta_{W}$ and the currently accepted value. In this paper we re-examine strange - anti-strange asymmetry using the meson cloud model. We calculate contributions to the strange sea arising from fluctuations in the proton wavefunction to states containing either Lambda or Sigma hyperons together with either Kaons or pseudovector $K^{*}$ mesons. We find that we should not ignore fluctuations involving $K^{*}$ mesons in this picture. The strange sea asymmetry is found to be small, and is unlikely to affect the analysis of the Llewellyn-Smith cross section ratios or the Paschos-Wolfenstein relationship.Comment: 12 pages, 3 figure

When the client is not the abuser, but one of the abused

The question of client confidentiality and reporting animal abuse is complicated when the client is not the abuser, and when the abuse (of both people and animals) may escalate precisely because it has been (or may be) reported