| 1. |
- Barausse, Enrico, et al.
(författare)
-
Prospects for fundamental physics with LISA
- 2020
-
Ingår i: General Relativity and Gravitation. - : SPRINGER/PLENUM PUBLISHERS. - 0001-7701 .- 1572-9532. ; 52:8
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, which is of programmatic rather than quantitative nature, we aim to further delineate and sharpen the future potential of the LISA mission in the area of fundamental physics. Given the very broad range of topics that might be relevant to LISA,we present here a sample of what we view as particularly promising fundamental physics directions. We organize these directions through a "science-first" approach that allows us to classify how LISA data can inform theoretical physics in a variety of areas. For each of these theoretical physics classes, we identify the sources that are currently expected to provide the principal contribution to our knowledge, and the areas that need further development. The classification presented here should not be thought of as cast in stone, but rather as a fluid framework that is amenable to change with the flow of new insights in theoretical physics.
|
|
| 2. |
|
|
| 3. |
- Ciemala, M., et al.
(författare)
-
Testing ab initio nuclear structure in neutron-rich nuclei : Lifetime measurements of second 2(+) state in C-16 and O-20
- 2020
-
Ingår i: Physical Review C. - : AMER PHYSICAL SOC. - 2469-9985 .- 2469-9993. ; 101:2
-
Tidskriftsartikel (refereegranskat)abstract
- To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2(+) state in neutron-rich O-20, tau(2(2)(+)) = 150(-30)(+80) fs, and an estimate for the lifetime of the second 2(+) state in C-16 have been obtained for the first time. The results were achieved via a novel Monte Carlo technique that allowed us to measure nuclear state lifetimes in the tens-to-hundreds of femtoseconds range by analyzing the Doppler-shifted gamma-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction O-18 (7.0 MeV/u) + Ta-181. The requested sensitivity could only be reached owing to the excellent performances of the Advanced gamma-Tracking Array AGATA, coupled to the PARIS scintillator array and to the VAMOS++ magnetic spectrometer. The experimental lifetimes agree with predictions of ab initio calculations using two- and three-nucleon interactions, obtained with the valence-space in-medium similarity renormalization group for O-20 and with the no-core shell model for C-16. The present measurement shows the power of electromagnetic observables, determined with high-precision gamma spectroscopy, to assess the quality of first-principles nuclear structure calculations, complementing common benchmarks based on nuclear energies. The proposed experimental approach will be essential for short lifetime measurements in unexplored regions of the nuclear chart, including r-process nuclei, when intense beams, produced by Isotope Separation On-Line (ISOL) techniques, become available.
|
|
| 4. |
|
|
| 5. |
- Kern, R., et al.
(författare)
-
Restoring the valence-shell stabilization in Nd 140
- 2020
-
Ingår i: Physical Review C. - 2469-9985. ; 102:4
-
Tidskriftsartikel (refereegranskat)abstract
- A projectile Coulomb-excitation experiment was performed at the radioactive-ion beam facility HIE-ISOLDE at CERN to obtain E2 and M1 transition matrix elements of Nd140 using the multistep Coulomb-excitation code gosia. The absolute M1 strengths, B(M1;22+→21+)=0.033(8)μN2,B(M1;23+→21+)=0.26-0.10+0.11μN2, and B(M1;24+→21+)<0.04μN2, identify the 23+ state as the main fragment of the one-quadrupole-phonon proton-neutron mixed-symmetry state of Nd140. The degree of F-spin mixing in Nd140 was quantified with the determination of the mixing matrix element VF-mix<7-7+13keV.
|
|
| 6. |
- Morrison, L., et al.
(författare)
-
Dealing with contaminants in Coulomb excitation of radioactive beams
- 2020
-
Ingår i: 27th International Nuclear Physics Conference (INPC2019) 29 July - 2 August 2019, Glasgow, UK. - : IOP Publishing. - 1742-6588. ; 1643
-
Konferensbidrag (refereegranskat)abstract
- Data analysis of the Coulomb excitation experiment of the exotic 206Hg nucleus, recently performed at CERN's HIE-ISOLDE facility, needs to account for the contribution to target excitation due to the strongly-present beam contaminant 130Xe. In this paper, the contamination subtraction procedure is presented.
|
|
| 7. |
- Morrison, L., et al.
(författare)
-
Quadrupole deformation of Xe 130 measured in a Coulomb-excitation experiment
- 2020
-
Ingår i: Physical Review C. - 2469-9985. ; 102:5
-
Tidskriftsartikel (refereegranskat)abstract
- Low-lying states in the isotope Xe130 were populated in a Coulomb-excitation experiment performed at CERN's HIE-ISOLDE facility. The magnitudes and relative signs of seven E2 matrix elements and one M1 matrix element coupling five low-lying states in Xe130 were determined using the semiclassical coupled-channel Coulomb-excitation least-squares search code gosia. The diagonal E2 matrix elements of both the 21+ and 41+ states were extracted for the first time. The reduced transition strengths are in line with those obtained from previous measurements. Experimental results were compared with the general Bohr Hamiltonian with the microscopic input from mean-field theory utilizing universal nuclear energy density functional (UNEDF0), shell-model calculations using the GCN50:82 and SN100PN interactions, and simple phenomenological models (Davydov-Filippov and γ-soft). The extracted shape parameters indicate triaxial-prolate deformation in the ground-state band. In general, good agreement between theoretical predictions and experimental values was found, while neither phenomenological model was found to provide an adequate description of Xe130.
|
|
| 8. |
|
|
| 9. |
- Stahl, K., et al.
(författare)
-
Search for proton emission of the isomeric 10+ state in 54Ni
- 2020
-
Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 56:1
-
Tidskriftsartikel (refereegranskat)abstract
- Several experiments were conducted at the 10 MV Van-de-Graaff tandem accelerator at the Institute of Nuclear Physics, Cologne, to detect proton emission from the isomeric 6457-keV 10+ state in 54Ni. Excitation functions for two fusion–evaporation reactions were measured to maximise the population of the rare two-neutron evaporation channel from a 56Ni compound nucleus. The search for delayed proton emission was based on the 28Si(28Si,2n)54Ni reaction at a beam energy of 70 MeV. For this reaction, a cross-section limit for the population of the 10+ state in 54Ni and its proton-decay branch was determined to be σ< 22 nb.
|
|
| 10. |
- van den Hombergh, Wieneke M.T., et al.
(författare)
-
Prediction of organ involvement and survival in systemic sclerosis patients in the first 5 years from diagnosis
- 2020
-
Ingår i: Journal of Scleroderma and Related Disorders. - : SAGE Publications. - 2397-1983 .- 2397-1991. ; 5:1, s. 57-65
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Organ involvement often occurs in early systemic sclerosis and has been related to premature death. Identifying patients at diagnosis at risk of developing early organ involvement would be useful to optimize screening and management strategies. Objective: To develop prediction models for the 5-year development of interstitial lung disease, pulmonary arterial hypertension and death. Methods: A European multicentre inception cohort was created. For modelling, predefined clinical variables with known predictive value at diagnosis were used. Univariate and multivariate regression analysis were done to select baseline predictors and build the prediction models. The models were tested using the area under the receiver operating characteristic curve comparing observed and expected frequencies. Results: Of 735 patients, 23% developed interstitial lung disease, 8% developed pulmonary arterial hypertension 12% died. The interstitial lung disease model included diffuse cutaneous systemic sclerosis (OR = 1.8), systemic sclerosis disease duration < 3 years (OR = 1.4), puffy fingers (OR = 1.6), and anti-topoisomerase-I-antibodies (OR = 1.8). The pulmonary arterial hypertension model included age > 65 years (OR = 3.2), forced vital capacity < 70% (OR = 2.5) and diffusing capacity of the lung for carbon monoxide < 55% (OR = 1.9). Death was predicted best by age > 65 years (OR = 4.1), male gender (OR = 1.9), no anti-centromere antibodies (OR = 0.5), proteinuria (OR = 1.9), forced vital capacity < 70% (OR = 1.8) and pulmonary arterial hypertension at diagnosis (OR = 10.1). The area under the receiver operating characteristic was 0.66 (95% CI 0.64–0.67), 0.66 (95% CI 0.64–0.68) and 0.70 (95% CI 0.69–0.72), respectively. Conclusion: We have shown that it is possible to predict interstitial lung disease, pulmonary arterial hypertension and death using established variables already available at the moment of systemic sclerosis diagnosis. Discriminatory performance of the models was suboptimal. Further research including new variables is necessary to improve performance.
|
|
