9 research outputs found
A high efficiency photon veto for the Light Dark Matter eXperiment
Fixed-target experiments using primary electron beams can be powerful discovery tools for light dark matter in the sub-GeV mass range. The Light Dark Matter eXperiment (LDMX) is designed to measure missing momentum in high-rate electron fixed-target reactions with beam energies of 4 GeV to 16 GeV. A prerequisite for achieving several important sensitivity milestones is the capability to efficiently reject backgrounds associated with few-GeV bremsstrahlung, by twelve orders of magnitude, while maintaining high efficiency for signal. The primary challenge arises from events with photo-nuclear reactions faking the missing-momentum property of a dark matter signal. We present a methodology developed for the LDMX detector concept that is capable of the required rejection. By employing a detailed Geant4-based model of the detector response, we demonstrate that the sampling calorimetry proposed for LDMX can achieve better than 10⁻¹³ rejection of few-GeV photons. This suggests that the luminosity-limited sensitivity of LDMX can be realized at 4 GeV and higher beam energies
A high efficiency photon veto for the Light Dark Matter eXperiment
Fixed-target experiments using primary electron beams can be powerful discovery tools for light dark matter in the sub-GeV mass range. The Light Dark Matter eXperiment (LDMX) is designed to measure missing momentum in high-rate electron fixed-target reactions with beam energies of 4 GeV to 16 GeV. A prerequisite for achieving several important sensitivity milestones is the capability to efficiently reject backgrounds associated with few-GeV bremsstrahlung, by twelve orders of magnitude, while maintaining high efficiency for signal. The primary challenge arises from events with photo-nuclear reactions faking the missing-momentum property of a dark matter signal. We present a methodology developed for the LDMX detector concept that is capable of the required rejection. By employing a detailed Geant4-based model of the detector response, we demonstrate that the sampling calorimetry proposed for LDMX can achieve better than 10⁻¹³ rejection of few-GeV photons. This suggests that the luminosity-limited sensitivity of LDMX can be realized at 4 GeV and higher beam energies
Photon-rejection Power of the Light Dark Matter eXperiment in an 8 GeV Beam
The Light Dark Matter eXperiment (LDMX) is an electron-beam fixed-target
experiment designed to achieve comprehensive model independent sensitivity to
dark matter particles in the sub-GeV mass region. An upgrade to the LCLS-II
accelerator will increase the beam energy available to LDMX from 4 to 8 GeV.
Using detailed GEANT4-based simulations, we investigate the effect of the
increased beam energy on the capabilities to separate signal and background,
and demonstrate that the veto methodology developed for 4 GeV successfully
rejects photon-induced backgrounds for at least electrons on
target at 8 GeV.Comment: 28 pages, 20 figures; corrected author lis
Optics Studies for the ATLAS Forward Proton Project
A brief report of a project consisting of writing a framework for performing optics studies is given, along with the full documentation of the new framework
Building a Distributed Computing System for LDMX
Particle physics experiments rely extensively on computing and data services, making e-infrastructure an integral part of the research collaboration. Constructing and operating distributed computing can however be challenging for a smaller-scale collaboration.
The Light Dark Matter eXperiment (LDMX) is a planned small-scale accelerator-based experiment to search for dark matter in the sub-GeV mass region. Finalizing the design of the detector relies on Monte-Carlo simulation of expected physics processes. A distributed computing pilot project was proposed to better utilize available resources at the collaborating institutes, and to improve scalability and reproducibility.
This paper outlines the chosen lightweight distributed solution, presenting requirements, the component integration steps, and the experiences using a pilot system for tests with large-scale simulations. The system leverages existing technologies wherever possible, minimizing the need for software development, and deploys only non-intrusive components at the participating sites. The pilot proved that integrating existing components can dramatically reduce the effort needed to build and operate a distributed e-infrastructure, making it attainable even for smaller research collaborations
A high efficiency photon veto for the Light Dark Matter eXperiment
Fixed-target experiments using primary electron beams can be powerful discovery tools for light dark matter in the sub-GeV mass range. The Light Dark Matter eXperiment (LDMX) is designed to measure missing momentum in high-rate electron fixed-target reactions with beam energies of 4 GeV to 16 GeV. A prerequisite for achieving several important sensitivity milestones is the capability to efficiently reject backgrounds associated with few-GeV bremsstrahlung, by twelve orders of magnitude, while maintaining high efficiency for signal. The primary challenge arises from events with photo-nuclear reactions faking the missing-momentum property of a dark matter signal. We present a methodology developed for the LDMX detector concept that is capable of the required rejection. By employing a detailed Geant4-based model of the detector response, we demonstrate that the sampling calorimetry proposed for LDMX can achieve better than 10−13 rejection of few-GeV photons. This suggests that the luminosity-limited sensitivity of LDMX can be realized at 4 GeV and higher beam energies. [Figure not available: see fulltext.
Current Status and Future Prospects for the Light Dark Matter eXperiment
The constituents of dark matter are still unknown, and the viable
possibilities span a vast range of masses. The physics community has
established searching for sub-GeV dark matter as a high priority and identified
accelerator-based experiments as an essential facet of this search strategy. A
key goal of the accelerator-based dark matter program is testing the broad idea
of thermally produced sub-GeV dark matter through experiments designed to
directly produce dark matter particles. The most sensitive way to search for
the production of light dark matter is to use a primary electron beam to
produce it in fixed-target collisions. The Light Dark Matter eXperiment (LDMX)
is an electron-beam fixed-target missing-momentum experiment that realizes this
approach and provides unique sensitivity to light dark matter in the sub-GeV
range. This contribution provides an overview of the theoretical motivation,
the main experimental challenges, how LDMX addresses these challenges, and
projected sensitivities. We further describe the capabilities of LDMX to
explore other interesting new and standard physics, such as visibly-decaying
axion and vector mediators or rare meson decays, and to provide timely
electronuclear scattering measurements that will inform the modeling of
neutrino-nucleus scattering for DUNE.Comment: 26 pages, 17 figures. Contribution to Snowmass 202