| 1. |
- Bergman, A. S., et al.
(författare)
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280 GHz Focal Plane Unit Design and Characterization for the SPIDER-2 Suborbital Polarimeter
- 2018
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Ingår i: Journal of Low Temperature Physics. - : Springer Science and Business Media LLC. - 0022-2291 .- 1573-7357. ; 193:5-6, s. 1075-1084
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Tidskriftsartikel (refereegranskat)abstract
- We describe the construction and characterization of the 280 GHz bolometric focal plane units (FPUs) to be deployed on the second flight of the balloon-borne SPIDER instrument. These FPUs are vital to SPIDER's primary science goal of detecting or placing an upper limit on the amplitude of the primordial gravitational wave signature in the cosmic microwave background (CMB) by constraining the B-mode contamination in the CMB from Galactic dust emission. Each 280 GHz focal plane contains a 16 x 16 grid of corrugated silicon feedhorns coupled to an array of aluminum-manganese transition-edge sensor (TES) bolometers fabricated on 150 mm diameter substrates. In total, the three 280 GHz FPUs contain 1530 polarization-sensitive bolometers (765 spatial pixels) optimized for the low loading environment in flight and read out by time-division SQUID multiplexing. In this paper, we describe the mechanical, thermal, and magnetic shielding architecture of the focal planes and present cryogenic measurements which characterize yield and the uniformity of several bolometer parameters. The assembled FPUs have high yields, with one array as high as 95% including defects from wiring and readout. We demonstrate high uniformity in device parameters, finding the median saturation power for each TES array to be similar to 3 pW at 300 mK with a less than 6% variation across each array at 1 sigma. These focal planes will be deployed alongside the 95 and 150 GHz telescopes in the SPIDER-2 instrument, slated to fly from McMurdo Station in Antarctica in December 2018.
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| 2. |
- Gualtieri, R., et al.
(författare)
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SPIDER : CMB Polarimetry from the Edge of Space
- 2018
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Ingår i: Journal of Low Temperature Physics. - : Springer Science and Business Media LLC. - 0022-2291 .- 1573-7357. ; 193:5-6, s. 1112-1121
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Tidskriftsartikel (refereegranskat)abstract
- SPIDER is a balloon-borne instrument designed to map the polarization of the millimeter-wave sky at large angular scales. Spider targets the B-mode signature of primordial gravitational waves in the cosmic microwave background (CMB), with a focus on mapping a large sky area with high fidelity at multiple frequencies. SPIDER's first long-duration balloon (LDB) flight in January 2015 deployed a total of 2400 antenna-coupled transition-edge sensors (TESs) at 90 GHz and 150 GHz. In this work we review the design and in-flight performance of the SPIDER instrument, with a particular focus on the measured performance of the detectors and instrument in a space-like loading and radiation environment. SPIDER's second flight in December 2018 will incorporate payload upgrades and new receivers to map the sky at 285 GHz, providing valuable information for cleaning polarized dust emission from CMB maps.
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| 3. |
- Nagy, J. M., et al.
(författare)
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A New Limit on CMB Circular Polarization from SPIDER
- 2017
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 844:2
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Tidskriftsartikel (refereegranskat)abstract
- We present a new upper limit on cosmic microwave background (CMB) circular polarization from the 2015 flight of SPIDER, a balloon-borne telescope designed to search for B-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the nonzero circular-to-linear polarization coupling of the half-wave plate polarization modulators, data from SPIDER's 2015 Antarctic flight provide a constraint on Stokes V at 95 and 150 GHz in the range 33 < l < 307. No other limits exist over this full range of angular scales, and SPIDER improves on the previous limit by several orders of magnitude, providing 95% C.L. constraints on l (l + 1)C-l(VV) /(2 pi) ranging from 141 to 255 mu K-2 at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain even stronger constraints on circular polarization.
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| 4. |
- Lee, James J, et al.
(författare)
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Gene discovery and polygenic prediction from a genome-wide association study of educational attainment in 1.1 million individuals.
- 2018
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 50:8, s. 1112-1121
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Tidskriftsartikel (refereegranskat)abstract
- Here we conducted a large-scale genetic association analysis of educational attainment in a sample of approximately 1.1million individuals and identify 1,271independent genome-wide-significant SNPs. For the SNPs taken together, we found evidence of heterogeneous effects across environments. The SNPs implicate genes involved in brain-development processes and neuron-to-neuron communication. In a separate analysis of the X chromosome, we identify 10independent genome-wide-significant SNPs and estimate a SNP heritability of around 0.3% in both men and women, consistent with partial dosage compensation. A joint (multi-phenotype) analysis of educational attainment and three related cognitive phenotypes generates polygenic scores that explain 11-13% of the variance in educational attainment and 7-10% of the variance in cognitive performance. This prediction accuracy substantially increases the utility of polygenic scores as tools in research.
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| 5. |
- Ade, Peter, et al.
(författare)
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The Simons Observatory : science goals and forecasts
- 2019
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :2
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Tidskriftsartikel (refereegranskat)abstract
- The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial con figuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping approximate to 10% of the sky to a white noise level of 2 mu K-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of sigma(r) = 0.003. The large aperture telescope will map approximate to 40% of the sky at arcminute angular resolution to an expected white noise level of 6 mu K-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.
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| 6. |
- Baum, Sebastian, et al.
(författare)
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NMSSM Higgs boson search strategies at the LHC and the mono-Higgs signature in particular
- 2017
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 95:11
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Tidskriftsartikel (refereegranskat)abstract
- We study the collider phenomenology of the extended Higgs sector of the next-to-minimal supersymmetric Standard Model (NMSSM). The region of NMSSM parameter space favored by a 125 GeV SM-like Higgs and naturalness generically features a light Higgs and neutralino spectrum as well as a large O(1) coupling between the Higgs doublets and the NMSSM singlet fields. In such regimes, the heavier Higgs bosons can decay dominantly into lighter Higgs bosons and neutralinos. We study the prospects of observing such decays at the 13 TeV LHC, focusing on mono-Higgs signatures as probes of such regions of parameter space. We present results for the mono-Higgs reach in a framework easily applicable to other models featuring similar decay topologies. In the NMSSM, we find that the mono-Higgs channel can probe TeV scale Higgs bosons and has sensitivity even in the low tan beta, large m(A) regime that is difficult to probe in the MSSM. Unlike for many conventional Higgs searches, the reach of the mono-Higgs channel will improve significantly with the increased luminosity expected to be collected at the LHC in the ongoing and upcoming runs.
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| 7. |
- Baum, Sebastian, et al.
(författare)
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The NMSSM is within reach of the LHC : mass correlations & decay signatures
- 2019
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Ingår i: Journal of High Energy Physics (JHEP). - : SPRINGER. - 1126-6708 .- 1029-8479. ; :4
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Tidskriftsartikel (refereegranskat)abstract
- The Next-to-Minimal Supersymmetric Standard Model (NMSSM), the singlet extension of the MSSM which fixes many of the MSSM's shortcomings, is shown to be within reach of the upcoming runs of the Large Hadron Collider (LHC). A systematic treatment of the various Higgs decay channels and their interplay has been lacking due to the seemingly large number of free parameters in the NMSSM's Higgs sector. We demonstrate that due to the SM-like nature of the observed Higgs boson, the NMSSM's Higgs and neutralino sectors have highly correlated masses and couplings and can effectively be described by four physically intuitive parameters: the physical masses of the two CP-odd states and their mixing angle, and tan , which plays a minor role. The heavy Higgs bosons in the NMSSM have large branching ratios into pairs of lighter Higgs bosons or a light Higgs and a Z boson. Search channels arising via these Higgs cascades are unique to models like the NMSSM with a Higgs sector larger than that of the MSSM. In order to cover as much of the NMSSM parameter space as possible, one must combine conventional search strategies employing decays of the additional Higgs bosons into pairs of SM particles with Higgs cascade channels. We demonstrate that such a combination would allow a significant fraction of the viable NMSSM parameter space containing additional Higgs bosons with masses below 1 TeV to be probed at future runs of the LHC.
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| 8. |
- Freese, Katherine, et al.
(författare)
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MSSM A-funnel and the galactic center excess : prospects for the LHC and direct detection experiments
- 2016
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Ingår i: Journal of High Energy Physics (JHEP). - : Springer-Verlag New York. - 1126-6708 .- 1029-8479. ; :4
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Tidskriftsartikel (refereegranskat)abstract
- The pseudoscalar resonance or "A-funnel" in the Minimal Supersymmetric Standard Model (MSSM) is a widely studied framework for explaining dark matter that can yield interesting indirect detection and collider signals. The well-known Galactic Center excess (GCE) at GeV energies in the gamma ray spectrum, consistent with annihilation of a less than or similar to 40 GeV dark matter particle, has more recently been shown to be compatible with significantly heavier masses following reanalysis of the background. In this paper, we explore the LHC and direct detection implications of interpreting the GCE in this extended mass window within the MSSM A-funnel framework. We find that compatibility with relic density, signal strength, collider constraints, and Higgs data can be simultaneously achieved with appropriate parameter choices. The compatible regions give very sharp predictions of 200-600 GeV CP-odd/even Higgs bosons at low tan beta at the LHC and spin-independent cross sections approximate to 10(-11) pb at direct detection experiments. Regardless of consistency with the GCE, this study serves as a useful template of the strong correlations between indirect, direct, and LHC signatures of the MSSM A-funnel region.
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