| Scientific Committee Paper | |
| Report number | CERN-SPSC-2024-024 ; SPSC-SR-352 |
| Title | NA64 Status Report 2024 |
| Project Manager/Technical Coordinator | Gninenko, Sergei |
| Author(s) | Crivelli, P ; Molina Bueno, L ; Banto Oberhauser, B |
| Corporate author(s) | CERN. Geneva. SPS and PS Experiments Committee ; SPSC |
| Collaboration | NA64 Collaboration |
| Series | (Status Report) |
| Note | co-spokesperson: Paolo Crivelli, ETH Zurich, [email protected] |
| Submitted by | [email protected] on 25 Aug 2024 |
| Subject category | Detectors and Experimental Techniques |
| Accelerator/Facility, Experiment | CERN SPS ; NA64 |
| Abstract | In this report, we focus mostly on the results obtained after unblinding the 2022 data using 160 GeV muons at the M2 beamline. We also report on the preliminary analysis of the 2023 data. Compared to 2022 an order of magnitude more statistics (1.5$\times10^{11}$ MOT) was collected with an upgraded setup featuring an additional magnetic spectrometer. The data show that the main background source from the miss-reconstruction of the incoming momentum is reduced by at least two orders of magnitude. Finally, we present the status of the ongoing 2024 run at M2 and give an overview of our plans before LS3 including the scenario of a possible run in 2026. Moreover, we summarise the current status of the analysis for the 2023 data collected at H4 with a setup upgraded with a prototype of a veto hadronic calorimeter (VHCAL) to suppress the dominant background from large-angle hadronic secondaries produced in the primary beam interactions upstream of the active target. With the collected statistics of $4.4\times10^{11}$ electrons on target (EOT), we demonstrate the effectiveness of this approach by reducing background to the negligible level and significantly improve the signal efficiency by increasing the missing energy threshold from 50 GeV to 60 GeV. The obtained results demonstrate the great potential of our approach and provide clear guidance for designing a full-scale optimized VHCAL (to be constructed during LS3) to make experiment background-free at a level of $10^{13}$ EOT that we expect to gather during RUN 4. This will allow us to enhance and extend the sensitivity for dark sector physics from future searches and decisively explore the well-motivated region of parameter space suggested by benchmark Light Dark Matter (LDM) models. \\ Our projections also show a significant gain when exploring LDM with the H4 $e^+$ beam via the annihilation channel since the mass range is extended. We also report on the run carried out at H4 in 2024. Preliminary results of a new LYSO-based synchrotron radiation detector prototype are presented together with the test of new faster electronics to readout the NA64 calorimeters. We conclude with our plans before LS3 including the scenario of a possible run at H4 in 2026. |
Email contact(s) : [email protected] ; [email protected]
Datensatz erzeugt am 2024-08-25, letzte Änderung am 2024-08-26
