English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

This thesis reports on two experiments conducted by the HAPPEx (Hall A Proton Parity Experiment) collaboration at the Thomas Je#11;erson National Accelerator Facil- ity. For both, the weak neutral current interaction (WNC, mediated by the Z{sup 0} boson) is used to probe novel properties of hadronic targets. The WNC interaction amplitude is extracted by measuring the parity-violating asymmetry in the elastic scattering of longitudinally polarized electrons o#11; unpolarized target hadrons. HAPPEx-III, con- ducted in the Fall of 2009, used a liquid hydrogen target at a momentum transfer of Q{sup 2} = 0.62 GeV{sup 2}. The measured asymmetry was used to set new constraints on the contribution of strange quark form factors (G{sup s}{sub E,M} ) to the nucleon electromagnetic form factors. A value of A{sub PV} = -23.803{+-}#6; 0.778 (stat){+-}#6; 0.359 (syst) ppm resulted in G{sup s}{sub E} + 0:517G{sup s}{sub M} = 0.003{+-} 0.010 (stat){+-} #6;0.004 (syst){+-}#6; #6;0.009 (FF). PREx, conducted in the Spring of 2010, used a polarized electron beam on a 208Pb target at a momentum transfer of Q{sup 2} = 0.009 GeV{sup 2}. This parity-violating asymmetry can be used to obtain a clean measurement of the root-mean-square radius of the neutrons in the {sup 208}Pb nucleus. The Z{sup 0} boson couples mainly to neutrons; the neutron weak charge is much larger than that of the proton. The value of this asymmetry is at the sub-ppm level and has a projected experimental fractional precision of 3%. We will describe the accelerator setup used to set controls on helicity-correlated beam asymmetries and the analysis methods for #12;nding the raw asymmetry for HAPPEx-III. We will also discuss in some detail the preparations to meet the ex- perimental challenges associated with measuring such a small asymmetry with the degree of precision required for PREx

Probing Novel Properties of Nucleons and Nuclei via Parity Violating Electron Scattering