********************************************************************** GAUSTEQ Germany and U.S. Nuclear Theory Exchange Program for QCD Studies of Hadrons and Nuclei *************************** VISITOR REPORT *************************** Please use the following template to prepare your report in plain text format. Short, itemized answers are preferred. Send your report by E-mail to (as an attachment to preserve formating). ---------------------------------------------------------------------- 1) NAME AND HOME INSTITUTION OF TRAVELER (INCL. E-MAIL ADDRESS) Fred Myhrer, University of South Carolina; myhrer@physics.sc.edu ---------------------------------------------------------------------- 2) POSITION OF TRAVELER (FACULTY/STAFF/POSTDOC/STUDENT) Professor ---------------------------------------------------------------------- 3) DATES OF TRAVEL June 15TH - July 18TH ---------------------------------------------------------------------- 4) INSTITUTIONS VISITED (LIST PLACES AND TIME SPENT THERE) A; Ruhr University Bochum (RUB), Germany (June 15TH - July 18TH, EXCEPT DURING Mainz VISIT) B; University of Mainz, Mainz, Germany (July 6th) ---------------------------------------------------------------------- 5) SCIENTIFIC CONTACTS AND COLLABORATORS (INDICATE NATURE OF CONTACTS, LIKE "NEW COLLABORATION," "CONTINUING COLLABORATION," "USEFUL DISCUSSION," ETC.) RUB ----- Continuing collaboration and useful discussions with E. Epelbaum, V. Baru, A. Gasparyan and H. Krebs. Mainz ----- Discussions on chiral effective theories and applications to electroweak processes with Stefan Scherer. ---------------------------------------------------------------------- 6) TOPICS DISCUSSED DURING VISIT The problems regarding inelastic reactions like pion production involving light nuclei was extensively discussed as was electroweak interactions in light nuclei leading to a new collaborative project with scientists from RUB. In Mainz I discussed the application of meson exchange models, which provide new additional neutrino producing reactions in supernova explosions. These models are tested in electron scattering off light nuclei. ---------------------------------------------------------------------- 7) IMPACT ON TRAVELER'S OR HOST'S RESEARCH (INCL. EXPECTED PUBLICATIONS) The trip allowed me to efficiently write the outline of a paper with my RUB/Juelich collaborators on the cross sections of pion production in proton proton collisions based on our developed chiral effective theory. In addition, the trip permitted the start of a new project for a higher order precision calculation of the muon capture on the deuteron relevant for the MuSun experiment at PSI and which will contribute to the determination of a low-energy-constant, d. This LEC will give an independent determination of one of the two LEC, c_D, in the chiral three-nucleon potential. During my stay in Germany I gave a seminar about my recent research in Mainz. ---------------------------------------------------------------------- 8) RELEVANCE TO JEFFERSON LAB OR GSI-FAIR (LIST RELEVANT PROGRAMS) The possible new collaborative project on electroweak interaction with the RUB scientists will explore the electromagnetic and weak structure of light nuclei utilizing effective field theory, topics which are very relevant for some JLab experiments. Especially, we explore in the chiral effective theory the axial current, which enters in parity violating experiments at JLab. This axial two-nucleon exchange current is being tested in our pion-production process and hopefully will lead to a better understanding and possible improvement of the current MEC approach. ---------------------------------------------------------------------- 9) SUGGESTIONS/RECOMMENDATIONS FOR PROGRAM ADMINISTRATORS (IF ANY) ------------ ---------------------------------------------------------------------- 10) SUPPORT PROVIDED BY HOSTS (INDICATE TYPE AND EXTENT OF SUPPORT, NOT EXACT AMOUNTS) RUB provided funds to pay the rented apartment in Bochum during my stay. ---------------------------------------------------------------------- 11) ACKNOWLEDGMENTS Please acknowledge support from the GAUSTEQ program in any publication benefiting from the results of your visit, by including the following text in your acknowledgments: "This work was supported partially through GAUSTEQ (Germany and U.S. Nuclear Theory Exchange Program for QCD Studies of Hadrons and Nuclei) under contract number DE-SC0006758." ---------------------------------------------------------------------- updated: Nov. 2011 **********************************************************************