Fundamental Problems at Intermediate Energies (Physics)

研究将在TRIUMF回旋加速器和伯克利超级希拉克设备上进行实验介子和重离子物理。工作将集中在(1)极化质子散射引起的介子轫致辐射和(2)高z核重离子碰撞产生的异常电子和正电子发射线。将在δ等压线激发区测量介子轫致辐射实验中的微分截面和不对称性，以研究长期以来与理论的分歧。重离子实验将在运动学上完成，检测电子和正电子与散射离子的重合，具有很高的统计精度，并使用比GSI达姆施塔特早期测量改进的检测系统。重离子测量解决了可能出现的新中性基本粒子、真空异常状态和奇异QED效应等问题。

Research will be carried out in experimental pion and heavy- ion physics at the TRIUMF cyclotron and at the Berkeley SuperHilac facility. The work will focus on (1) pion bremsstrahlung resulting from pion scattering from polarized protons, and (2) anomalous electron and positron emission lines produced in heavy ion collisions of high-Z nuclei. Differential cross sections and asymmetries in the pion bremsstrahlung experiment will be measured in the delta isobar excitation region to investigate longstanding disagreement with theory. The heavy- ion experiments will be kinematically complete, detecting electrons and positrons in coincidence with scattered ions, have high statistical accuracy, and use improved detection systems over earlier measurements at GSI Darmstadt. The heavy-ion measurement addresses issues raised concerning possible new neutral elementary particles, abnormal states of the vacuum, and exotic QED effects.