17 research outputs found
Constraining Light Thermal Inelastic Dark Matter with NA64
Get PDFA vector portal between the Standard Model and the dark sector is a
predictive and compelling framework for thermal dark matter. Through
co-annihilations, models of inelastic dark matter (iDM) and inelastic Dirac
dark matter (i2DM) can reproduce the observed relic density in the MeV to GeV
mass range without violating cosmological limits. In these scenarios, the
vector mediator behaves like a semi-visible particle, evading traditional
bounds on visible or invisible resonances, and uncovering new parameter space
to explain the muon anomaly. By means of a more inclusive signal
definition at the NA64 experiment, we place new constraints on iDM and i2DM
using a missing energy technique. With a recast-based analysis, we
contextualize the NA64 exclusion limits in parameter space and estimate the
reach of the newly collected and expected future NA64 data. Our results
motivate the development of an optimized search program for semi-visible
particles, in which fixed-target experiments like NA64 provide a powerful probe
in the sub-GeV mass range.Comment: 14 pages, 8 figure
Status and prospects of the NA64 experiment
No full textThe NA64 experiment at the CERN SPS has obtained the world-leading constraints in the search for Light Dark Matter (LDM) candidates with sub-GeV masses using an electron beam. Most recently, the complementarity of the physics case with the NA64 and NA64 programs has been established, in particular following the first results for searches with high-energy muons. Planned upgrades for all programs during the CERN's next long shutdown (LS3) are aimed at boosting the experiment data-taking capabilities and ensuring a low level of background, further enhancing the sensitivity to the uncharted region of the parameter space suggested by benchmark LDM models. Finally, the feasibility of Dark Sector (DS) searches with hadronic beams, NA64, has been demonstrated, opening a new avenue for exploration
Probing light dark matter with positron beams at NA64
No full textISSN:1550-7998ISSN:0556-2821ISSN:1550-2368ISSN:0556-2821ISSN:1550-236
Proof of principle for a light dark matter search with low-energy positron beams at NA64
No full textISSN:1126-6708ISSN:1029-8479ISSN:1029-847
Dark-Sector Search via Pion-Produced η and η′ Mesons Decaying Invisibly in the NA64h Detector
No full textISSN:0031-9007ISSN:1079-7114ISSN:1079-711
Shedding light on dark sectors with high-energy muons at the NA64 experiment at the CERN SPS
No full textISSN:1550-7998ISSN:0556-2821ISSN:1550-2368ISSN:0556-2821ISSN:1550-236
Probing hidden leptonic scalar portals using the NA64 experiment at CERN
No full textIn this study, we demonstrate the potential of the NA64 experiment at CERN SPS to search for New Physics processes involving transitions after the collision of 100 GeV electrons with target nuclei. A new Dark Sector leptonic portal in which a scalar boson could be produced in the lepton-flavor-changing bremsstrahlung-like reaction, , is used as benchmark process. In this work, we develop a realistic Monte Carlo simulation of the NA64 experimental setup implementing the differential and total production cross-section computed at exact tree-level and applying the Weiszäcker–Williams phase space approximation. Using this framework, we investigate the main background sources and calculate the expected sensitivity of the experiment. The results indicate that with minor setup optimization, NA64 can probe a large fraction of the available parameter space compatible with the muon anomaly and the Dark Matter relic predictions in the context of a new Dark Sector leptonic portal with EOT. This result paves the way to the exploration of lepton-flavour-changing transitions in NA64
Development of the fully Geant4 compatible package for the simulation of Dark Matter in fixed target experiments
No full textISSN:0010-4655ISSN:1879-2944ISSN:1879-294
Application of the VMM3a/SRS: A t0-less TWIN GEM-based TPC
No full textIntegrating the ATLAS/BNL VMM3a ASIC (Application Specific Integrated Circuit) into the RD51/SRS (Scalable Readout System) provides a self-triggered continuous readout system for various gaseous detectors.Since the system allows flexible parameters, such as switching the polarity, adjusting electronics gain or different peaking times, the settings can be adjusted for a wide range of detectors.The system allows particles to be recorded with a MHz interaction rate in energy, space, and time.The system is used as a trigger-less readout for the TWIN GEM-TPC (Gas ElectronMultiplier-Time Projection Chamber) to prove the operationwithout external t of such a TPC configuration. First results of position reconstruction withthe TWIN GEM-TPC are presented, with a spatial resolution around 220 µm in X, and330 µm in Y. Y is reconstructed from the time information, and X from the 1D stripreadout.Operating the setup as an ultra-low material budget tracking telescope, an angular distribution can be extracted in the horizontal and vertical planes.Giving distributions with σ = 0.15° in the horizontal plane and in the vertical plane σ between 0.3° and 0.9°, depending on the reconstruction method.Integrating the ATLAS/BNL VMM3a ASIC (Application Specific Integrated Circuit) into the RD51/SRS (Scalable Readout System) provides a self-triggered continuous readout system for various gaseous detectors. Since the system allows flexible parameters, such as switching the polarity, adjusting electronics gain or different peaking times, the settings can be adjusted for a wide range of detectors. The system allows particles to be recorded with a MHz interaction rate in energy, space, and time. The system will be introduced in the beginning, and short examples will be given for different applications. After, the Twin GEM TPC will be discussed in more detail to show the benefits of such a trigger-less system in combination with the Twin configuration. Last, a few results for the tracking performance and the possibility to operate as a tracking telescope will be shown. Thus, this presents the possibility of an extremely low material budget tracking system suitable for tracking from high to low-energy particle beams
