| 1. |
- Cederwall, Bo, et al.
(författare)
-
Evidence for a spin-aligned neutron-proton paired phase from the level structure of 92Pd
- 2011
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 469:7328, s. 68-71
-
Tidskriftsartikel (refereegranskat)abstract
- Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.
|
|
| 2. |
- Hadinia, Baharak, et al.
(författare)
-
First identification of excited states in 106Te and evidence for isoscalar-enhanced vibrational collectivity
- 2005
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 72:4, s. 041303-1-041303-5
-
Tidskriftsartikel (refereegranskat)abstract
- Gamma-ray transitions in the extremely neutron-deficient nucleus Te-106 have been identified for the first time. The experiment utilized the Fe-54(Fe-54,2n)Te-106(*) reaction, and the gamma-ray transitions from excited states in Te-106 were selected by use of the recoil-decay-tagging technique. The production cross section was estimated at 25 nb, a new limit for in-beam gamma-ray spectroscopy. A ground-state band tentatively extending up to I-pi=10(+) is proposed. The systematics of low-lying yrast states in the Te isotopes is discussed within the context of vibrational excitations and residual nucleon-nucleon interactions.
|
|
| 3. |
- Hadinia, Baharak, et al.
(författare)
-
First identification of gamma-rays in Te-106 using recoil decay tagging technique
- 2006
-
Ingår i: Frontiers in Nuclear Structure Astrophysics, and Reactions: FINUSTAR. - MELVILLE, NY : AMER INST PHYSICS. - 0735403236 - 9780735403239 ; , s. 457-459
-
Konferensbidrag (refereegranskat)abstract
- Gamma-ray transitions from excited states in Te-106 have been identified using the recoil decay tagging technique. The experiment which was the reaction Fe-54(Fe-54,2n)Te-106* was performed at the JYFL accelerator facility at the University of Jyvaskyla, Finland. The production cross section was estimated at 25 nb, a new limit for in-beam gamma-ray spectroscopy. A tentative level structure for the ground state band of Te-106 is proposed.
|
|
| 4. |
- Hadinia, Baharak, et al.
(författare)
-
In-beam gamma-ray and alpha-decay spectroscopy of 170Ir
- 2007
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 76:4, s. 044312-1-044312-8
-
Tidskriftsartikel (refereegranskat)abstract
- Excited states in the highly neutron deficient odd-odd nucleus Ir-170 have been investigated. The experiment was performed using the Sn-112(Ni-60, pn)Ir-170 reaction and employing the recoil-decay tagging technique. Gamma rays were detected using the JUROGAM gamma-ray spectrometer and those belonging to Ir-170 were selected based on recoil identification provided by the RITU gas-filled recoil separator and the GREAT spectrometer at the RITU focal plane. A partial level scheme of Ir-170 is presented for the first time. New alpha-decay branches are assigned to Ir-170 and a tentative level structure for Re-166 is deduced from a study of the alpha-decay fine structure and the associated alpha-gamma correlations.
|
|
| 5. |
- Sandzelius, Mikael, et al.
(författare)
-
First identification of excited states in 169Ir
- 2007
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 75:5, s. 054321-
-
Tidskriftsartikel (refereegranskat)abstract
- Gamma rays populating the alpha-decaying isomeric state in Ir-169 have been observed for the first time. The experiment employed the recoil-decay tagging method using the JUROGAM gamma-ray spectrometer, the RITU gas-filled recoil separator and the GREAT spectrometer located at the RITU focal plane. The gamma-ray cascade feeding the isomeric alpha-decaying state exhibits a rotational structure consistent with a h(11/2) proton coupled to a triaxially deformed core. The experimental results are compared with predictions from total Routhian surface calculations.
|
|
| 6. |
- Al-Khatib, A., et al.
(författare)
-
High-spin states in Ba-124
- 2005
-
Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 36:4, s. 1029-1032
-
Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Ba-124 were populated using the Ni-64 (Ni-64,4n) Ba-124 reaction at beam energies of 255 and 261 MeV. Gamma-ray coincidences were measured using the EUROBALL detector array. The charged-particle detector array DIAMANT provided channel selection. The previously known rotational bands are extended to higher spins. Five new hands are observed, one of them extends up to the spin 40h region.
|
|
| 7. |
- Andgren, Karin, et al.
(författare)
-
Low-spin collective behavior in the transitional nuclei Mo-86,Mo-88
- 2007
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 76:1, s. 014307-
-
Tidskriftsartikel (refereegranskat)abstract
- Low-spin structures in Mo-86,Mo-88 were populated using the Ni-58(Ar-36, x alpha yp) heavy-ion fusion-evaporation reaction at a beam energy of 111 MeV. Charged particles and gamma rays were emitted in the reactions and detected by the DIAMANT CsI ball and the EXOGAM Ge array, respectively. In addition to the previously reported low-to-medium spin states in these nuclei, new low-spin structures were observed. Angular correlation and linear polarization measurements were performed in order to unambiguously determine the spins and parities of intensely populated states in Mo-88. Quasiparticle Random Phase Approximation (QRPA) calculations were performed for the first and second excited 2(+) states in Mo-86 and Mo-88. The results are in qualitative agreement with the experimental results, supporting a collective interpretation of the low-spin states for these transitional nuclei.
|
|
| 8. |
|
|
| 9. |
- Autio, Hanna, et al.
(författare)
-
Historically Based Room Acoustic Analysis and Auralization ofa Church in the 1470s
- 2021
-
Ingår i: Applied Sciences. - : MDPI. - 1454-5101 .- 2076-3417. ; 11:4
-
Tidskriftsartikel (refereegranskat)abstract
- Worship space acoustics have been established as an important part of a nation’s cultural heritage and area of acoustic research, but more research is needed regarding the region of northern Europe. This paper describes the historical acoustics of an important abbey church in Sweden in the 1470s. A digital historical reconstruction is developed. Liturgical material specific to this location is recorded and auralized within the digital reconstruction, and a room acoustic analysis is performed. The analysis is guided by liturgical practices in the church and the monastic order connected to it. It is found that the historical sound field in the church is characterized by the existence of two distinct acoustical subspaces within it, each corresponding to a location dedicated to the daily services of the monastical congregations. The subspaces show significantly better acoustic conditions for liturgical activities compared to the nave, which is very reverberant under the conditions of daily services. Acoustic transmission from the two subspaces is limited, indicating that the monastic congregations were visually and acoustically separated from the visitors in the nave and each other.
|
|
| 10. |
- Bygdéus, Pia, 1963-, et al.
(författare)
-
Legitimitet och närvaro i klostersång
- 2019
-
Ingår i: Musikforskning idag 2019, Göteborgs universitet, 12–14 juni 2019. - : Svenska samfundet för musikforskning. ; , s. 12-12
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 2016 initierades ett samarbete mellan benediktinklostret Mariavall och Bygdéus/Strinnholm Lagergren. De 15 nunnorna önskade förbättra sitt sångsätt och repertoaren önskades få nytt syre, förbättras och arbetas med. I denna presentation demonstreras och presenteras några av de viktigaste resultaten från detta pågående arbete utifrån frågor om förändringsprocess, praktik och repertoar där åhörarna delvis själva får delta. Uppdraget att arbeta med kommuniteten har kommit att paras med ett syfte där Bygdéus/Strinnholm Lagergren studerar hur en sjungande grupp som lever i en avskild miljö förändrar sin sångliga praxis och förändringsprocesser i den. Metoden har bestått i aktivt repetitionsarbete med kommuniteten med efterföljande reflektion, fotodokumentation och portföljskrivning. Projektet är inne på sitt tredje år med besök en gång i halvåret under tre dagar vardera. Portföljskrivning har inneburit att systrarna besvarat samma frågor i slutet av två övningstillfällen per dag under tre dagar. Portföljsvaren är individuella. Systrarnas reflektioner finns insamlat kring de många olika moment, teman och systrarnas individuella uppfattning om det gemensamma arbetet vilka sedan tematiserats. I materialbearbetningen av portföljskrivning blir särskilt följande kategorier tydliga: akustiken och rummet, upplevelsen av gemensam sång, olika attityd till sång innanför och utanför liturgin, förflyttningar, varierande uppställningar och kroppspositioner, lyssnande under sång, samtidighet i sången, rädslor. Repertoarmässigt finns en önskan sedan projektets start att sjunga mer på latin, mer gregorianik, särskilt i mässans inledande sång introitus. Allt eftersom har arbetet även kommit att omfatta andra delar av den liturgiska musiken samt sånger som inte alls används i liturgin men har sociala och sångtekniska aspekter för det individuella såväl som kollektiva arbetet med rösten och sång i grupp. Generellt framträder ett mönster där systrarna vill hitta ett personligt förhållningssätt till en tradition med lång historia utan att förlora sin egen identitet.
|
|
