An Analysis of the Efficacy of the CSIM Cubesat for SSI Continuity

&nbsp; One of the many data-sets required by scientists seeking to understand Earth&rsquo;s climate is a long term record of solar variability over a wide range of spectral regions. Measurements of solar spectral irradiance (SSI) have been taken by two space-based missions: the SOlar Radiation and Climate Experiment (SORCE) and the Total and Spectral Solar Irradiance Sensor (TSIS), both primarily relying on two different implementations of the Spectral Irradiance Monitor (SIM) instru- ment. While large spacecraft like SORCE (and TSIS) are effective, there are problems associated with these types of missions; they are expensive and an instrument failure can put a continuous data record at risk. A potential solution to this problem can be found in a new emergent tech- nology in space-based observation, miniaturized single-instrument spacecraft colloquially known as CubeSats. In order to explore this alternative, the Compact Spectral Irradiance Monitor (CSIM) was built at LASP by professionals working with undergraduate students as a flight demonstration mission. Because of the relatively cheap cost and higher acceptable risk, CSIM could also afford to test new technologies. TSIS SIM measures SSI from 200nm to 2400nm (&sim;96% of the total solar irradiance, TSI), and CSIM is the first to make measurements from 200 nm all the way to 2800 nm (97.4% of TSI). To maintain accuracy of solar measurements, the SIM instrument needs to be corrected for optical degradation (common throughout all instruments measuring the sun directly). In developing a correction method for CSIM, slightly different analysis methods were required com- pared to TSIS and SORCE. Corrected data revealed that while this instrument is far from perfect, it performed well enough to merit further investigation into this technology. </div

First Direct Observation of Collider Neutrinos with FASER at the LHC

We report the first direct observation of neutrino interactions at a particle collider experiment. Neutrino candidate events are identified in a 13.6 TeV center-of-mass energy $pp$ collision data set of 35.4 fb${}^{-1}$ using the active electronic components of the FASER detector at the Large Hadron Collider. The candidates are required to have a track propagating through the entire length of the FASER detector and be consistent with a muon neutrino charged-current interaction. We infer $153^{+12}_{-13}$ neutrino interactions with a significance of 16 standard deviations above the background-only hypothesis. These events are consistent with the characteristics expected from neutrino interactions in terms of secondary particle production and spatial distribution, and they imply the observation of both neutrinos and anti-neutrinos with an incident neutrino energy of significantly above 200 GeV.Comment: Submitted to PRL on March 24 202

SENSEI: First Direct-Detection Results on sub-GeV Dark Matter from SENSEI at SNOLAB

International audienceWe present the first results from a dark matter search using six Skipper-CCDs in the SENSEI detector operating at SNOLAB. With an exposure of 534.9 gram-days from well-performing sensors, we select events containing 2 to 10 electron-hole pairs. After aggressively masking images to remove backgrounds, we observe 55 two-electron events, 4 three-electron events, and no events containing 4 to 10 electrons. The two-electron events are consistent with pileup from one-electron events. Among the 4 three-electron events, 2 appear in pixels that are likely impacted by detector defects, although not strongly enough to trigger our "hot-pixel" mask. We use these data to set world-leading constraints on sub-GeV dark matter interacting with electrons and nuclei

SENSEI: First Direct-Detection Results on sub-GeV Dark Matter from SENSEI at SNOLAB

International audienceWe present the first results from a dark matter search using six Skipper-CCDs in the SENSEI detector operating at SNOLAB. With an exposure of 534.9 gram-days from well-performing sensors, we select events containing 2 to 10 electron-hole pairs. After aggressively masking images to remove backgrounds, we observe 55 two-electron events, 4 three-electron events, and no events containing 4 to 10 electrons. The two-electron events are consistent with pileup from one-electron events. Among the 4 three-electron events, 2 appear in pixels that are likely impacted by detector defects, although not strongly enough to trigger our "hot-pixel" mask. We use these data to set world-leading constraints on sub-GeV dark matter interacting with electrons and nuclei

Search for Dark Photons with the FASER detector at the LHC

International audienceThe FASER experiment at the LHC is designed to search for light, weakly-interacting particles produced in proton-proton collisions at the ATLAS interaction point that travel in the far-forward direction. The first results from a search for dark photons decaying to an electron-positron pair, using a dataset corresponding to an integrated luminosity of 27.0 fb$^{-1}$ collected at center-of-mass energy $\sqrt{s} = 13.6$ TeV in 2022 in LHC Run 3, are presented. No events are seen in an almost background-free analysis, yielding world-leading constraints on dark photons with couplings $\epsilon \sim 2 \times 10^{-5} - 1 \times 10^{-4}$ and masses $\sim$ 17 MeV - 70 MeV. The analysis is also used to probe the parameter space of a massive gauge boson from a U(1)$_{B-L}$ model, with couplings $g_{B-L} \sim 5 \times 10^{-6} - 2 \times 10^{-5}$ and masses $\sim$ 15 MeV - 40 MeV excluded for the first time

Search for Dark Photons with the FASER detector at the LHC

The FASER experiment at the LHC is designed to search for light, weakly-interacting particles produced in proton-proton collisions at the ATLAS interaction point that travel in the far-forward direction. The first results from a search for dark photons decaying to an electron-positron pair, using a dataset corresponding to an integrated luminosity of 27.0 fb$^{-1}$ collected at center-of-mass energy $\sqrt{s} = 13.6$ TeV in 2022 in LHC Run 3, are presented. No events are seen in an almost background-free analysis, yielding world-leading constraints on dark photons with couplings $\epsilon \sim 2 \times 10^{-5} - 1 \times 10^{-4}$ and masses $\sim$ 17 MeV - 70 MeV. The analysis is also used to probe the parameter space of a massive gauge boson from a U(1)$_{B-L}$ model, with couplings $g_{B-L} \sim 5 \times 10^{-6} - 2 \times 10^{-5}$ and masses $\sim$ 15 MeV - 40 MeV excluded for the first time

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