Month

Interfacial and near interfacial crack growth phenomena in metal bonded alumina (open access)

Interfacial and near interfacial crack growth phenomena in metal bonded alumina

Metal/ceramic interfaces can be found in many engineering applications including microelectronic packaging, multi-layered films, coatings, joints, and composite materials. In order to design reliable engineering systems that contain metal/ceramic interfaces, a comprehensive understanding of interfacial and near interfacial failure mechanisms is necessary.
Date: March 1, 2002
Creator: Kruzic, Jamie Joseph
System: The UNT Digital Library
Study of the Delta (1232) Using Double Polarization Asymmetries (open access)

Study of the Delta (1232) Using Double Polarization Asymmetries

An extensive experimental program to measure the spin structure of the nucleus is underway in Hall B at Jefferson Lab using a polarized electron beam incident on a polarized target. Spin degrees of freedom offer the possibility to test, in an independent way, existing models of resonance electro-production. The present analysis selects the Delta{sup +} (1232) in the exclusive channel {rvec p}({rvec e}, e'p)pi{sup 0} from data of the EG1 run period, taken in the Fall of 1998, to extract single and double asymmetries in a Q{sup 2} range from 0.5 to 1.5 GeV{sup 2}/c{sup 2}. Results of the asymmetries are presented as a function of momentum transfer Q{sup 2}. A comparison with the Effective Lagrangian Model by R. Davidson and N. Mukhopadhyay, the unitary isobar model MAID, and the dynamic model by Sato and Lee was performed. The data were found to be generally in good agreement with the models and a x{sup 2} comparison preferred the Sato-Lee model, which is tailored for the Delta (1232) photo- and electro-production. The present results are the first measurement of asymmetries for the exclusive reaction {rvec p}({rvec e}, e'p)pi{sup 0} and will provide new constraints for the models.
Date: March 1, 2002
Creator: Biselli, Angela
System: The UNT Digital Library