8 research outputs found
SARS-CoV-2 Catalonia contact tracing program : evaluation of key performance indicators
Background: Guidance on SARS-CoV-2 contact tracing indicators have been recently revised by international public health agencies. The aim of the study is to describe and analyse contact tracing indicators based on Catalonia's (Spain) real data and proposing to update them according to recommendations. Methods: Retrospective cohort analysis including Catalonia's contact tracing dataset from 20 May until 31 December 2020. Descriptive statistics are performed including sociodemographic stratification by age, and differences are assessed over the study period. Results: We analysed 923,072 contacts from 301,522 SARS-CoV-2 cases with identified contacts (67.1% contact tracing coverage). The average number of contacts per case was 4.6 (median 3, range 1-243). A total of 403,377 contacts accepted follow-up through three phone calls over a 14-day quarantine period (84.5% of contacts requiring follow-up). The percentage of new cases declared as contacts 14 days prior to diagnosis evolved from 33.9% in May to 57.9% in November. All indicators significantly improved towards the target over time (p < 0.05 for all four indicators). Conclusions: Catalonia's SARS-CoV-2 contact tracing indicators improved over time despite challenging context. The critical revision of the indicator's framework aims to provide essential information in control policies, new indicators proposed will improve system delay's follow-up. The study provides information on COVID-19 indicators framework experience from country's real data, allowing to improve monitoring tools in 2021-2022. With the SARS-CoV-2 pandemic being so harmful to health systems and globally, is important to analyse and share contact tracing data with the scientific community
First -decay spectroscopy of and new -decay branches of
19 pags., 14 figs., 3 tabs.The  decay of the neutron-rich and was investigated experimentally in order to provide new insights into the nuclear structure of the tin isotopes with magic proton number above the shell. The -delayed -ray spectroscopy measurement was performed at the ISOLDE facility at CERN, where indium isotopes were selectively laser-ionized and on-line mass separated. Three -decay branches of were established, two of which were observed for the first time. Population of neutron-unbound states decaying via rays was identified in the two daughter nuclei of and , at excitation energies exceeding the neutron separation energy by 1 MeV. The -delayed one- and two-neutron emission branching ratios of were determined and compared with theoretical calculations. The -delayed one-neutron decay was observed to be dominant -decay branch of even though the Gamow-Teller resonance is located substantially above the two-neutron separation energy of . Transitions following the  decay of are reported for the first time, including rays tentatively attributed to . In total, six new levels were identified in on the basis of the coincidences observed in the and decays. A transition that might be a candidate for deexciting the missing neutron single-particle state in was observed in both  decays and its assignment is discussed. Experimental level schemes of and are compared with shell-model predictions. Using the fast timing technique, half-lives of the , and levels in were determined. From the lifetime of the state measured for the first time, an unexpectedly large transition strength was deduced, which is not reproduced by the shell-model calculations.M.P.-S. acknowledges the funding support from the Polish National Science Center under Grants No.
2019/33/N/ST2/03023 and No. 2020/36/T/ST2/00547 (Doctoral scholarship ETIUDA). J.B. acknowledges
support from the Universidad Complutense de Madrid under the Predoctoral Grant No. CT27/16-
CT28/16. This work was partially funded by the Polish National Science Center under Grants No.
2020/39/B/ST2/02346, No. 2015/18/E/ST2/00217, and No. 2015/18/M/ST2/00523, by the Spanish
government via Projects No. FPA2017-87568-P, No. RTI2018-098868-B-I00, No. PID2019-104390GB-I00,
and No. PID2019-104714GB-C21, by the U.K. Science and Technology Facilities Council (STFC), the German BMBF
under Contract No. 05P18PKCIA, by the Portuguese FCT under the Projects No. CERN/FIS-PAR/0005/2017, and
No. CERN/FIS-TEC/0003/2019, and by the Romanian IFA Grant CERN/ISOLDE. The research leading to these
results has received funding from the European Unionâs Horizon 2020 research and innovation programme under
Grant Agreement No. 654002. M.Str. acknowledges the funding from the European Unionâs Horizon 2020 research
and innovation program under Grant Agreement No. 771036 (ERC CoG MAIDEN). J.P. acknowledges support from the
Academy of Finland (Finland) with Grant No. 307685. Work at the University of York was supported under STFC Grants
No. ST/L005727/1 and No. ST/P003885/1
First beta-decay spectroscopy of In-135 and new beta-decay branches of In-134
The beta decay of the neutron-rich In-134 and In-135 was investigated experimentally in order to provide new insights into the nuclear structure of the tin isotopes with magic proton number Z = 50 above the N = 82 shell. The beta-delayed gamma-ray spectroscopy measurement was performed at the ISOLDE facility at CERN, where indium isotopes were selectively laser-ionized and on-line mass separated. Three beta-decay branches of In-134 were established, two of which were observed for the first time. Population of neutron-unbound states decaying via. rays was identified in the two daughter nuclei of In-134, Sn-134 and Sn-133, at excitation energies exceeding the neutron separation energy by 1 MeV. The beta-delayed one- and two-neutron emission branching ratios of In-134 were determined and compared with theoretical calculations. The beta-delayed one-neutron decay was observed to be dominant beta-decay branch of In-134 even though the Gamow-Teller resonance is located substantially above the two-neutron separation energy of Sn-134. Transitions following the beta decay of In-135 are reported for the first time, including. rays tentatively attributed to Sn-135. In total, six new levels were identified in Sn-134 on the basis of the beta.. coincidences observed in the In-134 and In-135 beta decays. A transition that might be a candidate for deexciting the missing neutron single-particle 13/2(+) state in Sn-133 was observed in both beta decays and its assignment is discussed. Experimental level schemes of Sn-134 and Sn-135 are compared with shell-model predictions. Using the fast timing technique, half-lives of the 2(+), 4(+), and 6(+) levels in Sn-134 were determined. From the lifetime of the 4(+) state measured for the first time, an unexpectedly large B(E2; 4(+)-> 2(+)) transition strength was deduced, which is not reproduced by the shell-model calculations.Peer reviewe
Detailed structure of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Sn</mml:mi><mml:mprescripts/><mml:none/><mml:mn>131</mml:mn></mml:mmultiscripts></mml:math> populated in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>ÎČ</mml:mi></mml:math> decay of isomerically purified <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>In</mml:mi><mml:mprescripts/><mml:none/><mml:mn>131</mml:mn></mml:mmultiscripts></mml:math> states
The excited structure of the single-hole nucleus Sn131 populated by the ÎČâ decay of In131 was investigated in detail at the ISOLDE facility at CERN. This new experiment took advantage of isomeric purification capabilities provided by resonant ionization, making it possible to independently study the decay of each isomer for the first time. The position of the first-excited Îœh11/2 neutron-hole state was confirmed via an independent mass spectroscopy experiment performed at the Ion Guide Isotope Separator On-Line facility at the University of JyvĂ€skylĂ€. The level scheme of Sn131 was notably expanded with the addition of 31 new Îł-ray transitions and 22 new excited levels. The Îł-emitting excited levels above the neutron separation energy in Sn131 were investigated, revealing a large number of states, which in some cases decay by transitions to other neutron-unbound states. Our analysis showed the dependence between the population of these states in Sn131 and the ÎČ-decaying In131 state feeding them. Profiting from the isomer selectivity, it was possible to estimate the direct ÎČ feeding to the 3/2+ ground and 11/2â isomeric states, disentangling the contributions from the three indium parent states. This made possible to resolve the discrepancies in logft for first-forbidden transitions observed in previous studies, and to determine the ÎČ-delayed neutron decay probability (Pn) values of each indium isomers independently. The first measurement of subnanosecond lifetimes in Sn131 was performed in this work. A short T1/2=18(4)âps value was measured for the 1/2+ neutron single-hole 332-keV state, which indicates an enhanced l-forbidden M1 behavior for the Îœ3s1/2â1âÎœ3d3/2â1 transition. The measured half-lives of high-energy states populated in the ÎČ decay of the (21/2+) second isomeric state (In131m2) provided valuable information on transition rates, supporting the interpretation of these levels as core-excited states analogous to those observed in the doubly-magic Sn132.
Published by the American Physical Society
2024
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Detailed spectroscopy of doubly magic Sn 132
18 pags., 11 figs., 4 tabs.The structure of the doubly magic Sn8250132 has been investigated at the ISOLDE facility at CERN, populated both by the ÎČ-decay of In132 and ÎČ - delayed neutron emission of In133. The level scheme of Sn132 is greatly expanded with the addition of 68 Îł transitions and 17 levels observed for the first time in the ÎČ decay. The information on the excited structure is completed by new Îł transitions and states populated in the ÎČ-n decay of In133. Improved delayed neutron emission probabilities are obtained both for In132 and In133. Level lifetimes are measured via the advanced time-delayed ÎČγγ(t) fast-timing method. An interpretation of the level structure is given based on the experimental findings and the particle-hole configurations arising from core excitations both from the N = 82 and Z = 50 shells, leading to positive- and negative-parity particle-hole multiplets. The experimental information provides new data to challenge the theoretical description of Sn132.We acknowledge the support of the ISOLDE Collaboration
and the ISOLDE technical teams, and by the European
Union Horizon 2020 research and innovation programme
under Grant Agreement No. 654002. This work was partially
funded by the Spanish government via Projects No. FPA2015-
65035-P, No. FPA-64969-P, No. FPA2017-87568-P, and
No. RTI2018-098868-B-I00; the Polish National Science
Center under Contracts No. UMO-2015/18/E/ST2/00217,
No. UMO-2015/18/M/ST2/00523, and No. UMO2019/33/N/ST2/03023; the Portuguese FCT via
CERN/FIS-NUC/0004/2015 project; the German BMBF
under Contract No. 05P18PKCIA; the Romanian IFA Grant
CERN/ISOLDE; and by grants from the U.K. Science
and Technology Facilities Council, the Research Foundation
Flanders (FWO, Belgium), the Excellence of Science program
(EOS, FWO-FNRS, Belgium), and the GOA/2015/010
(BOF KU Leuven). J.B. acknowledges support from the
Universidad Complutense de Madrid under the Predoctoral
Grant No. CT27/16-CT28/1
Detailed spectroscopy of doubly magic Sn-132
The structure of the doubly magic Sn has been
investigated at the ISOLDE facility at CERN, populated both by the
decay of In and -delayed neutron emission of
In. The level scheme of Sn is greatly expanded with the
addition of 68 -transitions and 17 levels observed for the first time
in the decay. The information on the excited structure is completed by
new -transitions and states populated in the -n decay of
In. Improved delayed neutron emission probabilities are obtained both
for In and In. Level lifetimes are measured via the Advanced
Time-Delayed (t) fast-timing method. An interpretation of
the level structure is given based on the experimental findings and the
particle-hole configurations arising from core excitations both from the
\textit{N} = 82 and \textit{Z} = 50 shells, leading to positive and negative
parity particle-hole multiplets. The experimental information provides new data
to challenge the theoretical description of Sn.Comment: 19 pages, 11 figures. Accepted for publication in Phys. Rev.
Detailed spectroscopy of doubly magic 132Sn
status: publishe