TY  - JOUR
AU  - Natochii, A. et al
AU  - Marinas, C.
PY  - 2023
DA  - 2023//
TI  - Measured and projected beam backgrounds in the Belle II experiment at the SuperKEKB collider
T2  - Nucl. Instrum. Methods Phys. Res. A
JO  - Nuclear Instruments & Methods in Physics Research A
SP  - 168550
EP  - 21pp
VL  - 1055
PB  - Elsevier
KW  - Detector background
KW  - Lepton collider
KW  - Monte-Carlo simulation
AB  - The Belle II experiment at the SuperKEKB electron-positron collider aims to collect an unprecedented data set of 50 ab-1 to study CP-violation in the B-meson system and to search for Physics beyond the Standard Model. SuperKEKB is already the world's highest-luminosity collider. In order to collect the planned data set within approximately one decade, the target is to reach a peak luminosity of 6 x 1035 cm-2 s-1by further increasing the beam currents and reducing the beam size at the interaction point by squeezing the betatron function down to betay* = 0.3 mm. To ensure detector longevity and maintain good reconstruction performance, beam backgrounds must remain well controlled. We report on current background rates in Belle II and compare these against simulation. We find that a number of recent refinements have significantly improved the background simulation accuracy. Finally, we estimate the safety margins going forward. We predict that backgrounds should remain high but acceptable until a luminosity of at least 2.8 x 1035 cm-2 s-1is reached for betay* = 0.6 mm. At this point, the most vulnerable Belle II detectors, the Time-of-Propagation (TOP) particle identification system and the Central Drift Chamber (CDC), have predicted background hit rates from single-beam and luminosity backgrounds that add up to approximately half of the maximum acceptable rates.
SN  - 0168-9002
UR  - https://arxiv.org/abs/2302.01566
UR  - https://doi.org/10.1016/j.nima.2023.168550
DO  - 10.1016/j.nima.2023.168550
LA  - English
N1  - WOS:001056103200001
ID  - Natochii+Marinas2023
ER  -