论文标题
$ e^+e^ - $ b-factory的梁极化的测量以及新的tau极化技术
Measurement of Beam Polarization at an $e^+e^-$ B-Factory with New Tau Polarimetry Technique
论文作者
论文摘要
巴巴尔合作证明了新的tau极化技术的第一个应用。这种极化技术利用了$τ$衰减产品的运动耦合到$τ$和初始状态电子的旋转状态，以精确确定$ e^+e^ - collider中的平均光束极化。在升级到偏振电子束之后，预计TAU极化技术将在Belle II上使用，在该偏光电子束上，人们已知平均光束极化的精度预计将是所提出的需要极化束的拟议未来测量中的主要系统不确定性。 Babar采用Tau Polarimetry，初步测量了PEP-II平均光束极化为$ \ langle p \ rangle = -0.0010 \ pm0.0036 _ {\ textrm {stat}}} \ pm0.0030
The BABAR collaboration has demonstrated the first application of the new Tau Polarimetry technique. This polarimetry technique exploits the kinematic coupling of $τ$ decay products to the spin states of the $τ$ and initial state electron, to precisely determine the average beam polarization in an $e^+e^-$ collider. The Tau Polarimetry technique is expected to be used at Belle II following an upgrade to a polarized electron beam, where the precision with which the average beam polarization is known is expected to be the dominant systematic uncertainty in proposed future measurements which require polarized beams. Applying Tau Polarimetry, BABAR has preliminarily measured the PEP-II average beam polarization to be $\langle P\rangle=-0.0010\pm0.0036_{\textrm{stat}}\pm0.0030_{\textrm{sys}}$.
