Measurement of the spin-correlation coefficients A{sub x,x} and A{sub y,y} in the quasi-free np → {pp}{sub s} π{sup −} reaction near threshold at ANKE-COSY

Journal Article · Wed Jan 15 04:00:00 EST 2014 · Physics of Particles and Nuclei

DOI:https://doi.org/10.1134/S1063779614010948· OSTI ID:22977360

Shmakova, V. ^[1]

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1. Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, Dubna (Russian Federation)

A kinematically complete double-polarization measurement of the quasi-free np → {pp}{sub s} π{sup −} reaction near threshold has been performed using the ANKE spectrometer at COSY-Jülich. Here {pp}{sub s} represents a two-proton system with an excitation energy less than 3 MeV. The transversely vector polarized deuteron beam and the internal polarized ANKE hydrogen target were used to determine the spin-correlation coefficients A{sub x,x} and A{sub y,y}. Events from the quasi-free np → dπ{sup 0} reaction were recorded simultaneously and used for both beam and target polarimetry. In addition, the product of the beam and target polarizations could be estimated from the A{sub y,y} coefficient. The storage cell within the polarized target was the main source of background events. Dedicated runs, with no gas in the cell and with the cell filled with N{sub 2} gas, were taken to study the backgrounds. The data analysis procedure and the initial results of the experiment are presented.

• OSTI ID: 22977360
• Journal Information: Physics of Particles and Nuclei, Journal Name: Physics of Particles and Nuclei Journal Issue: 1 Vol. 45; ISSN 1063-7796
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DATA ANALYSIS
DEUTERON BEAMS
POLARIZED TARGETS