Experimental study of the A(e,e'{pi}{sup +}) reaction on {sup 1}H, {sup 2}H, {sup 12}C, {sup 27}Al, {sup 63}Cu and {sup 197}Au.

Journal Article · Tue May 25 04:00:00 EDT 2010 · Physical Review, C (Nuclear Physics)

DOI:https://doi.org/10.1103/PhysRevC.81.055209· OSTI ID:1029096

Qian, X; Horn, T; Clasic, B; Arrington, J; Asaturyan, R; El Fassi, L; Zheng, X ^[1]

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1. Physics

Cross sections for the {sup 1}H(e,e'{pi}{sup +})n process on {sup 1}H, {sup 2}H, {sup 12}C, {sup 27}Al, {sup 63}Cu, and {sup 197}Au targets were measured at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) to extract nuclear transparencies. Data were taken from Q{sup 2}=1.1-4.7 GeV{sup 2} for a fixed center-of-mass energy of W=2.14 GeV. The ratio of {sigma}{sub L} and {sigma}{sub T} was extracted from the measured cross sections for {sup 1}H, {sup 2}H, {sup 12}C, and {sup 63}Cu targets at Q{sup 2}=2.15 and 4.0 GeV{sup 2}, allowing for additional studies of the reaction mechanism. In this article, we present the experimental setup and the analysis of the data in detail, including systematic uncertainty studies. Differential cross sections and nuclear transparencies as a function of the pion momentum at different values of Q{sup 2} are presented. Our results are consistent with the predicted early onset of color transparency in mesons. Global features of the data are discussed and the data are compared with model calculations for the {sup 1}H(e,e'{pi}{sup +})n reaction from nuclear targets.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC; NSF; NSREC - Canada
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1029096
• Report Number(s): ANL/PHY/JA-65429
• Journal Information: Physical Review, C (Nuclear Physics), Journal Name: Physical Review, C (Nuclear Physics) Journal Issue: 5 Vol. 81; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

43 PARTICLE ACCELERATORS
CEBAF ACCELERATOR
COLOR
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
MESONS
PIONS
REACTION KINETICS
TARGETS