Determination of the COSY Proton Beam Polarization Using the WASA Detector
I. Schätti-Ozerianska (The Marian Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland); P. Moskal (The Marian Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland); M. Zieliński (The Marian Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland)
The dynamics of $\eta$-meson production and the interaction of $\eta$ mesons with nucleons can be studied using the $\vec{p}p\to pp\eta$ reaction via measurements of the analyzing power $A_{y}$. To this end, we have performed a measurement of the $\vec{p}p\to pp\eta$ reaction using the WASA-at-COSY detector, which provides large acceptance and is $\varphi$-symmetric. The experiment was carried out for the beam momenta of $2026$~MeV/$c$ and $2188$~MeV/$c$. In this article, we present a method and results for the determination of the degree of the beam polarization.
