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- Aprile, E., et al.
(författare)
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Emission of single and few electrons in XENON1T and limits on light dark matter
- 2022
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 106:2
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Tidskriftsartikel (refereegranskat)abstract
- Delayed single- and few-electron emissions plague dual-phase time projection chambers, limiting their potential to search for light-mass dark matter. This paper examines the origins of these events in the XENON1T experiment. Characterization of the intensity of delayed electron backgrounds shows that the resulting emissions are correlated, in time and position, with high-energy events and can effectively be vetoed. In this work we extend previous S2-only analyses down to a single electron. From this analysis, after removing the correlated backgrounds, we observe rates <30 events/(electron×kg×day) in the region of interest spanning 1 to 5 electrons. We derive 90% confidence upper limits for dark matter-electron scattering, first direct limits on the electric dipole, magnetic dipole, and anapole interactions, and bosonic dark matter models, where we exclude new parameter space for dark photons and solar dark photons.
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| 2. |
- Aprile, E., et al.
(författare)
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Effective Field Theory and Inelastic Dark Matter Results from XENON1T
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this work we expand on the XENON1T nuclear recoil searches and study the individual signals of Dark Matter interactions from operators up to dimension-eight in a Chiral Effective Field Theory (ChEFT) as well as a model of inelastic Dark Matter using data from the two science runs of the detector totalling 1 tonne*year exposure. For these analyses we extended the region of interest from [4.9, 40.9]keVnr to [4.9, 54.4]keVnr to enhance our sensitivity for signals that peak at nonzero energies. We show that the data is consistent with a background only hypothesis, with small excesses in the models which peak between 20 and 50keVnr, obtaining a maximum local discovery significance of 1.7 for the VVs ChEFT model for a WIMP mass of 70GeV/c2, and 1.8 for an iDM particle of 50GeV/c2 with a mass splitting of 100keV/c2. For each model we report 90% confidence level upper limits. We also report limits on three benchmark models of WIMP interaction using ChEFT for which we investigate the effect of isospin breaking interactions, reporting up to 6 orders of magnitude weaker limits with respect to the isospin conserving case driven by cancellations in the expected rate.
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| 9. |
- Grahn, J. V., et al.
(författare)
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A low-complexity 62-GHz f(T) SiGe heterojunction bipolar transistor process using differential epitaxy and in situ phosphorus-doped poly-Si emitter at very low thermal budget
- 2000
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Ingår i: Solid-State Electronics. - 0038-1101 .- 1879-2405. ; 44:3, s. 549-554
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Tidskriftsartikel (refereegranskat)abstract
- A low-complexity SiGe heterojunction bipolar transistor process based on differential epitaxy and in situ phosphorus doped polysilicon emitter technology is described. Silane-based chemical vapor deposition at reduced pressure was used for low-temperature SiGe epitaxy. Following SiGe epitaxy, the process temperature budget was kept very low with 900 degrees C for 10 s as the highest temperature step. A very high current gain of almost 2000 and cut off frequency of 62 GHz were achieved for a uniform 12% Ge profile. The breakdown voltage BVCEO and forward Early voltage were equal to 2.9 and 6.5 V, respectively.
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| 10. |
- Johansson, C., et al.
(författare)
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Atopy patch test reactions to Malassezia allergens differentiate subgroups of atopic dermatitis patients.
- 2003
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Ingår i: British Journal of Dermatology. - : Oxford University Press (OUP). - 1365-2133 .- 0007-0963. ; 148:3, s. 479-488
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Tidskriftsartikel (refereegranskat)abstract
- Background The yeast Malassezia is considered to be one of the factors that can contribute to atopic dermatitis (AD). Objectives To investigate the reactivity to Malassezia allergens, measured as specific serum IgE, positive skin prick test and positive atopy patch test (APT), in adult patients with AD. Methods In total, 132 adult patients with AD, 14 with seborrhoeic dermatitis (SD) and 33 healthy controls were investigated for their reactions to M. sympodialis extract and three recombinant Malassezia allergens (rMal s 1, rMal s 5 and rMal s 6). Results Sixty-seven per cent of the AD patients, but only one of the SD patients and none of the healthy controls, showed a positive reaction to at least one of the Malassezia allergens (extract and/or recombinant allergens) in at least one of the tests. The levels of M. sympodialis-specific IgE in serum correlated with the total serum IgE levels. Elevated serum levels of M. sympodialis-specific IgE were found in 55% and positive APT reactions in 41% of the AD patients with head and neck dermatitis. A relatively high proportion of patients without head and neck dermatitis and patients with low total serum IgE levels had a positive APT for M. sympodialis, despite lower proportions of individuals with M. sympodialis-specific IgE among these groups of patients. Conclusions These results support that Malassezia can play a role in eliciting and maintaining eczema in patients with AD. The addition of an APT to the test battery used in this study reveals a previously overlooked impact of Malassezia hypersensitivity in certain subgroups of AD patients.
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