Electroproduction of Φ(1020) Mesons at High Q² with CLAS

Thesis/Dissertation · Thu Oct 11 04:00:00 EDT 2007

DOI:https://doi.org/10.2172/955478· OSTI ID:955478

Santoro, Joseph P. ^[1]

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1. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

This analysis studies the reaction ep → e'p'φ in the kinematical range 1.6 ≤ Q² ≤ 3.8 GeV² and 2.0 ≤ W ≤ 3.0 GeV at CLAS. After successful signal identification, total and differential cross sections are measured and compared to the world data set. Comparisons are made to the predictions of the Jean-Mart Laget (JML) model based on Pomeron plus 2-gluon exchange. The overall scaling of the total cross section was determined to be 1/Q^4.6+/-1.7 which is compatible within errors to the Vector Meson Dominance prediction of 1/ Q⁴ as well as to the expected behavior of a quark and gluon exchange-dominated model described by Generalized Parton Distributions of 1/Q⁶. The differential cross section dσ/dΦ was used to determine that the s-channel helicity conservation (SCHC) assumption is valid within the precision of the current data. SCHC leads to a simple expression for the decay angular distribution from which R, the ratio of the longitudinal to the transverse cross section, can be extracted. Under the assumption of SCHC, we determine R = 1.33 ± 0.18 at an average Q² of 2.21 GeV² which leads to a determination of the longitudinal cross section s_L = 5.3 ± 1.3 nb for exclusive φ production.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 955478
• Report Number(s): JLAB-PHY--04-314
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ELECTROPRODUCTION
MESONS
SPECTROMETERS