| 1. |
- Aaltonen, T., et al.
(författare)
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Combination of Tevatron Searches for the Standard Model Higgs Boson in the W+W- Decay Mode
- 2010
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:6, s. 061802-
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Tidskriftsartikel (refereegranskat)abstract
- We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb(-1) of p (p) over bar collisions at root s = 1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard model Higgs boson in the mass range 162-166 GeV at the 95% C.L.
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| 2. |
- Hasselstrom, J, et al.
(författare)
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Ammonia adsorbed on Cu(110): An angle resolved x-ray spectroscopic and ab initio study
- 1999
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Ingår i: JOURNAL OF CHEMICAL PHYSICS. - : AMER INST PHYSICS. - 0021-9606. ; 110:10, s. 4880-4890
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We present a study of a monolayer of ammonia (NH3) adsorbed on Cu(110) using core level spectroscopies in combination with ab initio calculations based on density functional theory. In particular, x-ray emission spectroscopy has been applied, providing an
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| 3. |
- Hasselstrom, J, et al.
(författare)
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The adsorption structure of glycine adsorbed on Cu(110); comparison with formate and acetate/Cu(110)
- 1998
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Ingår i: SURFACE SCIENCE. - : ELSEVIER SCIENCE BV. - 0039-6028. ; 407:1-3, s. 221-236
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The molecular orientation of an ordered monolayer of glycine adsorbed on Cu(110) has been studied using X-ray Photoelectron Spectroscopy (XPS), Near Edge X-ray Absorption Fine Structure (NEXAFS), X-ray Photoelectron Diffraction (XPD), Low-Energy Electron
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| 4. |
- Karis, O, et al.
(författare)
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The bonding of simple carboxylic acids on Cu(110)
- 2000
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Ingår i: JOURNAL OF CHEMICAL PHYSICS. - : AMER INST PHYSICS. - 0021-9606. ; 112:18, s. 8146-8155
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Tidskriftsartikel (refereegranskat)abstract
- We present a study of the bonding of formate (HCOO) and acetate (CH3COO) chemisorbed on Cu(110) using core level spectroscopies in combination with theoretical calculations. For the first time, we apply x-ray emission spectroscopy (XES) to these systems.
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| 5. |
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| 6. |
- Nilsson, A, et al.
(författare)
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Local probing of the surface chemical bond using X-ray emission spectroscopy
- 1997
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Ingår i: APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING. - : SPRINGER VERLAG. - 0947-8396. ; 65:2, s. 147-154
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- X-ray emission spectroscopy applied to adsorbate systems is shown to reveal new details of the chemical bond formed at surfaces. An atom and symmetry projected view of the bonding orbitals is obtained. We will present recent studies of N-2 and CO on Ni(10
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| 7. |
- Weinelt, M, et al.
(författare)
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Electronic structure of benzene on Ni(100) and Cu(110): An x-ray-spectroscopy study
- 1998
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Ingår i: PHYSICAL REVIEW B-CONDENSED MATTER. - : AMERICAN PHYSICAL SOC. - 0163-1829. ; 58:11, s. 7351-7360
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The valence electronic structure of benzene chemisorbed on Ni(100) and Cu(110) has been studied using angle-dependent x-ray emission and x-ray absorption spectroscopy. These techniques allow us to resolve the benzene p contributions involved in the chemic
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| 8. |
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| 9. |
- Frietsch, B., et al.
(författare)
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Disparate ultrafast dynamics of itinerant and localized magnetic moments in gadolinium metal
- 2015
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- The Heisenberg-Dirac intra-atomic exchange coupling is responsible for the formation of the atomic spin moment and thus the strongest interaction in magnetism. Therefore, it is generally assumed that intra-atomic exchange leads to a quasi-instantaneous aligning process in the magnetic moment dynamics of spins in separate, on-site atomic orbitals. Following ultrashort optical excitation of gadolinium metal, we concurrently record in photoemission the 4f magnetic linear dichroism and 5d exchange splitting. Their dynamics differ by one order of magnitude, with decay constants of 14 versus 0.8 ps, respectively. Spin dynamics simulations based on an orbital-resolved Heisenberg Hamiltonian combined with first-principles calculations explain the particular dynamics of 5d and 4f spin moments well, and corroborate that the 5d exchange splitting traces closely the 5d spin-moment dynamics. Thus gadolinium shows disparate dynamics of the localized 4f and the itinerant 5d spin moments, demonstrating a breakdown of their intra-atomic exchange alignment on a picosecond timescale.
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| 10. |
- Frietsch, B., et al.
(författare)
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The role of ultrafast magnon generation in the magnetization dynamics of rare-earth metals
- 2020
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Ingår i: Science Advances. - : American Association for the Advancement of Science. - 2375-2548. ; 6:39
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Tidskriftsartikel (refereegranskat)abstract
- Ultrafast demagnetization of rare-earth metals is distinct from that of 3d ferromagnets, as rare-earth magnetism is dominated by localized 4f electrons that cannot be directly excited by an optical laser pulse. Their demagnetization must involve excitation of magnons, driven either through exchange coupling between the 5d6s-itinerant and 4f-localized electrons or by coupling of 4f spins to lattice excitations. Here, we disentangle the ultrafast dynamics of 5d6s and 4f magnetic moments in terbium metal by time-resolved photoemission spectroscopy. We show that the demagnetization time of the Tb 4f magnetic moments of 400 fs is set by 4f spin-lattice coupling. This is experimentally evidenced by a comparison to ferromagnetic gadolinium and supported by orbital-resolved spin dynamics simulations. Our findings establish coupling of the 4f spins to the lattice via the orbital momentum as an essential mechanism driving magnetization dynamics via ultrafast magnon generation in technically relevant materials with strong magnetic anisotropy.
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| 11. |
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| 12. |
- Karis, O, et al.
(författare)
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One-step and two-step description of deexcitation processes in weakly interacting systems
- 1996
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Ingår i: PHYSICAL REVIEW LETTERS. - : AMER INST PHYSICS. ; 76:8, s. 1380-1383
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The origin of one- and two-step behavior of core-hole decay processes is identified in connection with high resolution autoionization spectra for Ar/Pt(111). The spectra simultaneously show features of the two types (resonant Raman vs Auger-like behavior)
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| 13. |
- Magnuson, Martin, 1965-, et al.
(författare)
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Coherent and Incoherent Processes in resonant Photoemission
- 1997
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Ingår i: Advanced Light Source. - California, USA : Ernest Orlando Lawrence Berkeley National Laboratory, University of California Berkeley. ; 65:2, s. 159-167
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Bokkapitel (populärvet., debatt m.m.)
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| 14. |
- Martensson, N, et al.
(författare)
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Coherent and incoherent processes in resonant photoemission
- 1997
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Ingår i: APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING. - 0947-8396. ; 65:2, s. 159-167
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The basis for resonant photoemission is discussed in connection with data for a physisorption system, Ar/Pt(111) and a 3d transition metal, Ni(100). For Ar/Pt(111) the quasi-localized character of the intermediate state leads to two types of features in t
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| 15. |
- Nilsson, A, et al.
(författare)
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An atom-specific look at the surface chemical bond
- 1997
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Ingår i: PHYSICAL REVIEW LETTERS. - : AMER INST PHYSICS. - 0031-9007. ; 78:14, s. 2847-2850
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- High resolution x-ray emission spectroscopy is shown to reveal unprecedented details of the chemical bond formed between a molecule and a transition metal surface. An atom and symmetry projected view of the bonding orbitals is obtained. We find that all o
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| 16. |
- Nyberg, M, et al.
(författare)
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The electronic structure and surface chemistry of glycine adsorbed on Cu(110)
- 2000
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Ingår i: JOURNAL OF CHEMICAL PHYSICS. - : AMER INST PHYSICS. - 0021-9606. ; 112:12, s. 5420-5427
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Tidskriftsartikel (refereegranskat)abstract
- We present a combined density functional theory and x-ray emission spectroscopy study of the bonding and chemistry of glycine (NH2CH2COOH) chemisorbed on Cu(110). The amino acid deprotonates upon adsorption. The adsorbate exhibits a rich surface chemistry
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| 17. |
- Triguero, L., et al.
(författare)
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Direct experimental measurement of donation/back-donation in unsaturated hydrocarbon bonding to metals
- 2000
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 122:49, s. 12310-12316
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Tidskriftsartikel (refereegranskat)abstract
- Using resonant and off-resonant X-ray emission spectroscopy, in combination with ground-state density functional calculations, we examine the electronic structure of chemisarbed ethylene and benzene on thr Cu(110) surface to investigate the suitability of the donation/back-donation bonding model given by Dewar(1) and Chart and Duncanson(2) (DCD) for the interaction of unsaturated hydrocarbons with metal surfaces. We give an experimental verification of the DCD model and find donation/back-donation to be twice as large for ethylene as for benzene. In particular, the degree of sigma-pi mixing (rehybridization) is found to correspond to the amount of donation/back-donation, which is put in relation to the aromatic and nonaromatic pi characters of benzene and ethylene, respectively.
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| 18. |
- Triguero, L, et al.
(författare)
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Direct experimental measurement of donation/back-donation in unsaturated hydrocarbon bonding to metals
- 2000
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Ingår i: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. - : AMER CHEMICAL SOC. - 0002-7863. ; 122:49, s. 12310-12316 Language: English
-
Tidskriftsartikel (refereegranskat)abstract
- Using resonant and off-resonant X-ray emission spectroscopy, in combination with ground-state density functional calculations, we examine the electronic structure of chemisarbed ethylene and benzene on thr Cu(110) surface to investigate the suitability of
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| 19. |
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| 20. |
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| 21. |
- Weinelt, M., et al.
(författare)
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Resonant Photoemission at the 2p Edges of Ni: Resonant Raman and Interference Effects
- 1997
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 78:5, s. 967-970
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Tidskriftsartikel (refereegranskat)abstract
- Unambiguous evidence for resonant photoemission in Ni is presented. Interference effects are identified at the 2p edges for the valence band and the 6 eV satellite. A rapid transition from a resonant Raman to an Auger-like regime shows that the core-excited states above threshold are not localized enough to significantly enhance the photoemission intensity, implying a large fraction of incoherent intensity. The results indicate that the appearance of interference effects does not require strong localization of the intermediate state.
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| 22. |
- Weinelt, M, et al.
(författare)
-
Resonant photoemission at the 2p edges of Ni: Resonant Raman and interference effects
- 1997
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Ingår i: PHYSICAL REVIEW LETTERS. - 0031-9007. ; 78:5, s. 967-970
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Unambiguous evidence for resonant photoemission in Ni is presented. Interference effects are identified at the 2p edges for the valence band and the 6 eV satellite. A rapid transition from a resonant Raman to an Auger-like regime shows that the core-excit
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