A New Uniform Calibration Method for Double-Sided Silicon Strip Detectors
We proposed and implemented a new uniform calibration approach for double-sided silicon strip detector, named the self-calibration method (SCM). This method uses the strips on one side of the detector as references, to calibrate the strips on the other side, and vice versa. This calibration method has the inherent advantages that it can be run during the experiment corresponding exactly to the required particle type and energy range, and provides good statistics based on flexible selection of the event samples. Two strategies based on the same working principle but with deferent complexities, named simple SCM and overall SCM, were introduced and examined experimentally. The simple SCM requires less computation but a large number of events, while the overall SCM exhibits excellent performance even with a relatively small number of events.
Breakup of 12C resonances into three α particles
The reaction He-3 + B-11 -> d + C-12* has been used to populate resonances in C-12 up to an excitation energy of 15 MeV. The subsequent breakup to three alpha particles has been measured in complete kinematics. Dalitz plots are used to visualize and analyze the data. The Dalitz plot intensity distribution exhibits zero points characteristic of the total spin and parity of the 3 alpha system allowing us to determine the spin and parity of a state in C-12 at 13.35 MeV whose quantum numbers were hitherto not well established. The Dalitz plot intensity distributions of the 2(-) state at 11.83 MeV and the 1(+) state at 12.71 MeV are compared with the predictions of a recent three-body calculation as well as with simpler models. All are able to reproduce the gross structures seen in the Dalitz plot, but none give an accurate description of the detailed profile of the distributions.
Energy distributions from three-body decaying many-body resonances.
We compute energy distributions of three particles emerging from decaying many-body resonances. We reproduce the measured energy distributions from decays of two archetypal states chosen as the lowest 0+ and 1+ resonances in 12C populated in beta decays. These states are dominated by sequential, through the 8Be ground state, and direct decays, respectively. These decay mechanisms are reflected in the "dynamic" evolution from small, cluster or shell-model states, to large distances, where the coordinate or momentum space continuum wave functions are accurately computed.