Spin Density Matrix Elements in Exclusive Muoproduction of ρ0 and ω Mesons at COMPASS
Result description
Spin Density Matrix Elements (SDMEs) describe the transition processes between initial spin states of the virtual photon and final spin states of the produced vector meson and provide an important input for modelling Generalised Parton Distributions (GPDs). The SDMEs are measured in hard exclusive muoproduction of ρ0 and ω mesons on the proton using ±80% polarised μ+ and μ- beams with energy 160 GeV scattering off a liquid hydrogen target. Significant deviation from the hypothesis of s-channel helicity conservation is observed. The results for exclusive ρ0 meson show dominant contribution of natural-parity-exchange amplitudes and a small contribution of unnatural-parity-exchange amplitudes at small values of W. On the contrary, results for exclusive ω meson indicate significant contribution of unnatural-parity-exchange amplitudes that decreases with increasing W.
Keywords
The result's identifiers
Result code in IS VaVaI
Result on the web
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Spin Density Matrix Elements in Exclusive Muoproduction of ρ0 and ω Mesons at COMPASS
Original language description
Spin Density Matrix Elements (SDMEs) describe the transition processes between initial spin states of the virtual photon and final spin states of the produced vector meson and provide an important input for modelling Generalised Parton Distributions (GPDs). The SDMEs are measured in hard exclusive muoproduction of ρ0 and ω mesons on the proton using ±80% polarised μ+ and μ- beams with energy 160 GeV scattering off a liquid hydrogen target. Significant deviation from the hypothesis of s-channel helicity conservation is observed. The results for exclusive ρ0 meson show dominant contribution of natural-parity-exchange amplitudes and a small contribution of unnatural-parity-exchange amplitudes at small values of W. On the contrary, results for exclusive ω meson indicate significant contribution of unnatural-parity-exchange amplitudes that decreases with increasing W.
Czech name
—
Czech description
—
Classification
Type
O - Miscellaneous
CEP classification
—
OECD FORD branch
10303 - Particles and field physics
Result continuities
Project
LTT17018: Getting new knowledge of the microworld using the CERN infrastructure
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Basic information
Result type
O - Miscellaneous
OECD FORD
Particles and field physics
Year of implementation
2022