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Abstract FASER, the ForwArd Search ExpeRiment, is an experiment dedicated to searching for light, extremely weakly-interacting particles at CERN's Large Hadron Collider (LHC). Such particles may be produced in the very forward direction of the LHC's high-energy collisions and then decay to visible particles inside the FASER detector, which is placed 480 m downstream of the ATLAS interaction point, aligned with the beam collisions axis. FASER also includes a sub-detector, FASERν, designed to detect neutrinos produced in the LHC collisions and to study their properties. In this paper, each component of the FASER detector is described in detail, as well as the installation of the experiment system and its commissioning using cosmic-rays collected in September 2021 and during the LHC pilot beam test carried out in October 2021. FASER has successfully started taking LHC collision data in 2022, and will run throughout LHC Run 3.
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This content will become publicly available on January 1, 2026
The W-Si High Precision Preshower Detector of the FASER Experiment at the LHC
FASER is searching for light, weakly-interacting particles at the Large Hadron Collider. The first search for Axion-like particles (ALPs) decaying to a photon pair using data collected in 2022 and 2023 was performed and successfully excluded regions not previously ruled out. To further reduce neutrino background, a new preshower detector will be installed by the end of 2024. The detector is based on a monolithic active pixel sensor in 130 nm SiGe BiCMOS, which will allow resolving the photon pairs interacting in the preshower detector. The final ASICs have been produced in May 2024 and are currently being validated.
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- Award ID(s):
- 2111427
- PAR ID:
- 10638208
- Publisher / Repository:
- EPJC
- Date Published:
- Journal Name:
- EPJ Web of Conferences
- Volume:
- 320
- ISSN:
- 2100-014X
- Page Range / eLocation ID:
- 00056
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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