1. reconstruction in final state Jaewon Park University of Rochester MINERvA/Jupiter Group Meeting, May 23, 2007

2. 2 Enhance pi0 energy resolution using chi-squire minimization wit h pi0 mass constraint Next step is including angular contribution.

3. 3 Angle between two gammas For the first step, I’m tryin g to use average RMS of c os(theta) After making code work fo r average RMS, I can modi fy it to use RMS function o f pi0 energy RMS function will be deter mined from single pi0 parti cle event with each energy (theta=0deg) Angle RMS decrease as e nergy increases. It is diffe rent from RMS of gamma energy

4. 4 How to check the result Some combinatorial cases (1) Pi0 resolution without chi-square fit using true angle (2) Pi0 resolution after chi-square(E) fit using true angle (3) Pi0 resolution after chi-square(E) fit using reconstructed angle (4) Pi0 resolution after chi-square(E, angle) fit using reconstructed angle It’s not fair to compare between (2) and (4) I have compared (1) and (2) to show that chi-square(E) fit enhanced the pi0 resolution. I can compare (3) and (4) to show that chi-square(E, angle) fit enha nced pi0 resolution.