Hall D Polarization DeterminationI. Physics Requirements

Beam polarization is a required input to the partial wave analysis (PWAPWA). The PWAPWA fit sensitivity to the value of pp will differ from one channel to

another, depending on the physical analyzing power Aanalyzing power A in that channel:

AA and 0 have different sensitivities to small amplitude components.

There are cases where AA is primary discriminator between solutions.

SystematicsSystematics on acceptance will limit precision on measured ±

Limiting case: where A where A ±1 then ±1 then p p few % would be useful. few % would be useful.

± = 0 (1 ± pp AA) where AA [-1,1].

±

0 few % pp |AA| few %

Hall D Polarization DeterminationII. Plans for Polarimetry

Primary method:

Expected precision: pp = 5%= 5%

Systematics may ultimately be pushed down to 2-3%

The expected initial 5% precision will be sufficient for The expected initial 5% precision will be sufficient for many analysis channels and doing substantially better may many analysis channels and doing substantially better may await further motivation from await further motivation from actual physics analysis.actual physics analysis.

CB spectral shape analysisCB spectral shape analysis

requires cross checking with requires cross checking with complementary methodscomplementary methods