At the beginning of 2024, the data taking of the Belle II experiment resumed after the long-shutdown 1, required to install a new two-layer DEPFET detector (PXD) and upgrade accelerator components. The whole silicon tracker (VXD) was extracted, the two halves of the outer strip detector (SVD) were split for the PXD insertion and reconnected again. The new VXD was commissioned for the start of the new run. We will describe the challenges of this VXD upgrade and report on the operational experience and the SVD performance obtained with this first-year data. We then introduce the various improvements in the reconstruction procedure, that exploit the excellent SVD hit-time resolution to enhance beam-induced background rejection and reduce track fake-rate, crucial aspects for the higher luminosity regime.
Reinstallation and performance of the Belle II Silicon Vertex Detector
Corona L.;Bettarini S.;Casarosa G.;Forti F.;Massaccesi L.;Mondal S.;Paoloni E.;Rizzo G.;Tenchini F.;Zani L.;
2025-01-01
Abstract
At the beginning of 2024, the data taking of the Belle II experiment resumed after the long-shutdown 1, required to install a new two-layer DEPFET detector (PXD) and upgrade accelerator components. The whole silicon tracker (VXD) was extracted, the two halves of the outer strip detector (SVD) were split for the PXD insertion and reconnected again. The new VXD was commissioned for the start of the new run. We will describe the challenges of this VXD upgrade and report on the operational experience and the SVD performance obtained with this first-year data. We then introduce the various improvements in the reconstruction procedure, that exploit the excellent SVD hit-time resolution to enhance beam-induced background rejection and reduce track fake-rate, crucial aspects for the higher luminosity regime.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
