| 1. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Carninci, P, et al.
(författare)
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The transcriptional landscape of the mammalian genome
- 2005
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Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 309:5740, s. 1559-1563
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Tidskriftsartikel (refereegranskat)abstract
- This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5′ and 3′ boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.
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| 3. |
- Klug, Stefanie J, et al.
(författare)
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TP53 codon 72 polymorphism and cervical cancer : a pooled analysis of individual data from 49 studies
- 2009
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Ingår i: The Lancet Oncology. - 1470-2045 .- 1474-5488. ; 10:8, s. 772-784
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cervical cancer is caused primarily by human papillomaviruses (HPV). The polymorphism rs1042522 at codon 72 of the TP53 tumour-suppressor gene has been investigated as a genetic cofactor. More than 80 studies were done between 1998 and 2006, after it was initially reported that women who are homozygous for the arginine allele had a risk for cervical cancer seven times higher than women who were heterozygous for the allele. However, results have been inconsistent. Here we analyse pooled data from 49 studies to determine whether there is an association between TP53 codon 72 polymorphism and cervical cancer. METHODS: Individual data on 7946 cases and 7888 controls from 49 different studies worldwide were reanalysed. Odds ratios (OR) were estimated using logistic regression, stratifying by study and ethnic origin. Subgroup analyses were done for infection with HPV, ethnic origin, Hardy-Weinberg equilibrium, study quality, and the material used to determine TP53 genotype. FINDINGS: The pooled estimates (OR) for invasive cervical cancer were 1.22 (95% CI 1.08-1.39) for arginine homozygotes compared with heterozygotes, and 1.13 (0.94-1.35) for arginine homozygotes versus proline homozygotes. Subgroup analyses showed significant excess risks only in studies where controls were not in Hardy-Weinberg equilibrium (1.71 [1.21-2.42] for arginine homozygotes compared with heterozygotes), in non-epidemiological studies (1.35 [1.15-1.58] for arginine homozygotes compared with heterozygotes), and in studies where TP53 genotype was determined from tumour tissue (1.39 [1.13-1.73] for arginine homozygotes compared with heterozygotes). Null results were noted in studies with sound epidemiological design and conduct (1.06 [0.87-1.29] for arginine homozygotes compared with heterozygotes), and studies in which TP53 genotype was determined from white blood cells (1.06 [0.87-1.29] for arginine homozygotes compared with heterozygotes). INTERPRETATION: Subgroup analyses indicated that excess risks were most likely not due to clinical or biological factors, but to errors in study methods. No association was found between cervical cancer and TP53 codon 72 polymorphism when the analysis was restricted to methodologically sound studies.
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| 4. |
- Kitajima, M., et al.
(författare)
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Angle-resolved photoion yield and resonant Auger spectroscopy for the doubly excited Rydberg states above the C 1s threshold of CO
- 2008
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 78:3, s. 033422-
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Tidskriftsartikel (refereegranskat)abstract
- Doubly excited core-hole states of carbon monoxide in the photon energy region of 300-305 eV, i.e., directly above the C 1s ionization threshold, have been studied using both angle-resolved ion-yield and high-resolution resonant Auger spectroscopies. The leading configurations of the most prominent doubly excited Rydberg states are assigned by careful analysis of the ion-yield spectra and the final-state spectra to C 1s(-1) (5 sigma(-1)2 pi S-1=1) 3s sigma (v'=0,1,2), C 1s(-1) (5 sigma(-1)2 pi S-1=0) 3s sigma (v'=0,1,2), and C 1s(-1) (5 sigma(-1)2 pi S-1=1) 4s sigma (v'=0,1), which can only be populated via a conjugate shake-up process. Analysis of the resonant Auger spectra provides an assignment of several two-hole-one-electron (2h-1e) final states.
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| 5. |
- Sorensen, S. L., et al.
(författare)
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Electronic Doppler effect in resonant Auger decay of CO molecules upon excitation near a shake-up Pi resonance
- 2007
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - : APS. - 1050-2947 .- 1094-1622. ; 76:062704
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Tidskriftsartikel (refereegranskat)abstract
- Wepresent an experimental observation of the electronic Doppler effect inresonant Auger spectra upon core excitation slightly above the carbonK edge of the CO molecule. Thus the electronic Dopplereffect has been identified in above-threshold excitation, and in atransition of symmetry. Ab initio calculations of the potentialenergy curves of the relevant states of CO and thewave packet technique have been employed to provide a theoreticalbackground to the experimental studies. The weak feature around 299.4 eVin the photoabsorption spectrum, whose decay has been investigated bythe present experiment, is assigned to double (core-valence) excitations toC 1s shake-up states |1s1−1*2 with a strong dissociative character,and the Doppler splitting of the atomic peak has beenreproduced by the simulation.
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| 6. |
- Tanaka, T., et al.
(författare)
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Symmetry and vibrationally resolved absorption spectra near the OK edge of N2O : Experiment and theory
- 2007
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 435:4-6, s. 182-187
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Tidskriftsartikel (refereegranskat)abstract
- Angle-resolved energetic-ion yield spectra have been measured in the 0 Is excitation region of N2O. Franck-Condon analysis based on ab initio two-dimensional potential energy surfaces of the core-excited Rydberg states reproduces well the observed vibrational excitations specific to the individual Rydberg states. The irregular Rydberg behavior in the Sigma-symmetry absorption spectrum is attributed the valence-Rydberg coupling in light of the second moment analysis.
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| 7. |
- Céolin, A, et al.
(författare)
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Study of the Dissociation of Nitrous Oxide Following Resonant Excitation of the Nitrogen and Oxygen K-shells
- 2008
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 128:2, s. 024306-
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Tidskriftsartikel (refereegranskat)abstract
- A photochemistry study on nitrous oxide making use of site-selective excitation of terminal nitrogen, central nitrogen, and oxygen 1s -> 3 pi excitations is presented. The resonant Auger decay which takes place following excitation can lead to dissociation of the N2O+ ion. To elucidate the nuclear dynamics, energy-resolved Auger electrons were detected in coincidence with the ionic dissociation products, and a strong dependence of the fragmentation pathways on the core-hole site was observed in the binding energy region of the first satellite states. A description based on the molecular orbitals as well as the correlation between the thermodynamical thresholds of ion formation and the first electronic states of N2O+ has been used to qualitatively explain the observed fragmentation patterns.
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| 8. |
- Feifel, R., et al.
(författare)
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X-ray absorption and resonant Auger spectroscopy of O(2) in the vicinity of the O 1s ->sigma* resonance : Experiment and theory
- 2008
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Ingår i: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 128:6
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Tidskriftsartikel (refereegranskat)abstract
- We report on an experimental and theoretical investigation of x-ray absorption and resonant Auger electron spectra of gas phase O(2) recorded in the vicinity of the O 1s ->sigma* excitation region. Our investigation shows that core excitation takes place in a region with multiple crossings of potential energy curves of the excited states. We find a complete breakdown of the diabatic picture for this part of the x-ray absorption spectrum, which allows us to assign an hitherto unexplained fine structure in this spectral region. The experimental Auger data reveal an extended vibrational progression, for the outermost singly ionized X (2)Pi(g) final state, which exhibits strong changes in spectral shape within a short range of photon energy detuning (0 eV>Omega>-0.7 eV). To explain the experimental resonant Auger electron spectra, we use a mixed adiabatic/diabatic picture selecting crossing points according to the strength of the electronic coupling. Reasonable agreement is found between experiment and theory even though the nonadiabatic couplings are neglected. The resonant Auger electron scattering, which is essentially due to decay from dissociative core-excited states, is accompanied by strong lifetime-vibrational and intermediate electronic state interferences as well as an interference with the direct photoionization channel. The overall agreement between the experimental Auger spectra and the calculated spectra supports the mixed diabatic/adiabatic picture.
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| 9. |
- Kukk, E., et al.
(författare)
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Electronic state dependence in the dissociation of core-ionized methane
- 2007
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 40:18, s. 3677-3692
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Tidskriftsartikel (refereegranskat)abstract
- Methane and deuteromethane molecules were core ionized using synchrotron radiation, and the ionic fragments from the molecular dissociation were detected in coincidence with the Auger electrons. The electron - ion coincidence spectra are analysed in terms of partial ion yields and ion kinetic energy distributions, both as functions of electron kinetic energy. The dependence of the fragmentation patterns on the electronic character of the Auger final states as well as on the excess energy available for dissociating the molecule is studied. The analysis reveals marked differences in the dissociation of the 2a(1)(-2) and 2a(1)(-1) 1t(2)(-1) states, interpreted as an `excess- energy- dependent' concerted dissociation process for the 2a(1)(-2) state and an ` electronic- state- dependent' sequential process for the 2a(1)(-1) 1t(2)(-1) state.
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| 10. |
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