SciPost logo

Spin Density Matrix Elements for Exclusive $\rho^{0}$ Meson Muoproduction at COMPASS


SciPost Phys. Proc. 8, 073 (2022) · published 12 July 2022

Proceedings event

28th Annual Workshop on Deep-Inelastic Scattering (DIS) and Related Subjects


Spin density matrix elements were extracted from COMPASS data for exclusive $\rho^{0}$ meson muoproduction on a liquid hydrogen target. The measurement cover the kinematic range of 1.0 (GeV/$c$)$^2$ $< Q^{2} <$ 10.0 (GeV/$c$)$^2$, 5.0 GeV/$c^2$ $< W <$ 17.0 GeV/$c^2$ and 0.01 (GeV/$c$)$^2$ $<p^{2}_{T} < $ 0.5 (GeV/$c$)$^2$. Here, $W$ denotes the mass of the final hadronic system, $Q^{2}$ the virtuality of the exchanged photon and $p_{T}$ the transverse momentum of the $\rho^{0}$ meson with respect to the virtual-photon direction. We observe a violation of s-channel helicity conservation for the transition $\gamma^{*}_{T} \to \rho^{0}_{L}$. Additionally, we find a dominant contribution of the natural-parity-exchange transitions.

Author / Affiliation: mappings to Contributors and Organizations

See all Organizations.
Funder for the research work leading to this publication