Jan 26 – 30, 2015
Bormio, Italy
Europe/Berlin timezone

Concept of the $K_{S}^{0}$ rescue system for the Belle II PXD

Jan 30, 2015, 6:00 PM
Bormio, Italy

Bormio, Italy

Short Contribution Friday Afternoon


Mr Leonard Koch


The Belle II experiment at KEK in Tsukuba, Japan will perform studies with B mesons with a factor $\times 40$ increased luminosity compared to the Belle experiment. One of the main goals of Belle II is the search for physics beyond the Standard Model, for example in rare B meson decays described by with loop diagrams. Detecting $B$ mesons frequently involves the detection of $K_{S}^{0}$ with its displaced decay vertex. The innermost detector of Belle II is the DEPFET pixel detector (PXD) with an expected occupancy of $\leq 3\%$ due to high background. In order to reduce the data, only hits inside region-of-interests (ROIs) are read out. The ROIs are determined by extrapolation into the PXD region of tracks in the surrounding detector, the Silicon Vertex Detector (SVD), and the outer detectors. Thus every PXD hit of a particle, which does not create a valid track in the track finder, and subsequently no ROI, will not be recorded. Frequently pions originating from a (far off) secondary vertex of a $K_{S}^{0}$ decay do not create sufficient hits in the SVD. As a consequence, a significant amount of $K_{S}^{0}$ mesons will be lost. In this contribution, we present a concept for a the $K_{S}^{0}$ - rescue system. Here, we perform online tracking using six of the PXD and SVD layers to find the tracks of these pions, resulting in significantly improved $K_{S}^{0}$ reconstruction efficiency.

Primary author

Mr Leonard Koch (JLU Giessen)

Presentation materials