Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Density dependence of the pairing interaction and pairing correlation in unstable nuclei
KTH, School of Engineering Sciences (SCI), Physics.
KTH, School of Engineering Sciences (SCI), Physics.ORCID iD: 0000-0002-1406-5695
2015 (English)In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 91, no 2, 024305Article in journal (Refereed) Published
Abstract [en]

This work aims at a global assessment of the effect of the density dependence of the zero-range pairing interaction. Systematic Skyrme-Hartree-Fock-Bogoliubov calculations with the volume, surface, and mixed pairing forces are carried out to study the pairing gaps in even-even nuclei over the whole nuclear chart. Calculations are also done in coordinate representation for unstable semimagic even-even nuclei. The calculated pairing gaps are compared with empirical values from four different odd-even staggering formulas. Calculations with the three pairing interactions are comparable for most nuclei close to the beta-stability line. However, the surface interaction calculations predict neutron pairing gaps in neutron-rich nuclei that are significantly stronger than those given by themixed and volume pairing. On the other hand, calculations with volume andmixed pairing forces show noticeable reduction of neutron pairing gaps in nuclei far from stability.

Place, publisher, year, edition, pages
American Physical Society , 2015. Vol. 91, no 2, 024305
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:kth:diva-162961DOI: 10.1103/PhysRevC.91.024305ISI: 000350174000001Scopus ID: 2-s2.0-84922511228OAI: oai:DiVA.org:kth-162961DiVA: diva2:799875
Funder
Swedish Research Council
Note

QC 20150331

Available from: 2015-03-31 Created: 2015-03-26 Last updated: 2017-12-04Bibliographically approved
In thesis
1. Pairing correlation in atomic nuclei under extreme conditions
Open this publication in new window or tab >>Pairing correlation in atomic nuclei under extreme conditions
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The pairing correlation has long been recognized as the dominant many-body correlation beyond the nuclear mean field. Pairing plays an essential role in many nuclear phenomena including the occurrence of a systematic odd-even staggering (OES) of the nuclear binding energy. Pairing interaction plays, in particular, a significant role in the stability of weakly bound nuclei. Therefore it has been one of the most critical topics in nuclear physics because of the weakly bound structure of all newly discovered nuclei. Beyond the line of stability, pairing interaction is not a residual interaction anymore. Its strength can be of the same order of magnitude as the mean field.  In this thesis we have focused on the pairing interaction in atomic nuclei under extreme conditions to investigate the structure of loosely bound nuclei near the dripline; to probe and globally assess different outcomes of various zero-range pairing interactions and their effect on the loosely bound low angular momentum states. How much can density-dependence in zero-range pairing interaction nuclei affect the line of stability? Calculations predict that pure density-dependent pairing interaction so-called surface interaction enhances the collectivity and gives stronger neutron pairing gap in nuclei far from stability, while, the density dependence pairing interaction does not affect the gap for bound nuclei as much. The odd-even staggering of nuclear binding energies has been investigated to estimate the empirical pairing gap. A 3-point formula Δ(3)C (1/2[B(N,Z)+B(N −2,Z)−2B(N −1,Z)]) is advocated in this thesis, which we believe it is more suitable to measure the magnitude of pairing gap in even-even nuclei. The strength of Δ(3)C can be a good indicator of the two-particle spatial correlation. One-quasiparticle energies and binding energy for those odd nuclei, which can be approximated by spherical symmetry, are calculated to obtain binding energy odd-even staggering (OES) in all known semi-magic even-even nuclei. The pairing strength is fitted globally to all available data on the OES of semi-magic nuclei with Z ≥ 8. The difference between different zero-range density-dependent pairing interactions reduces with this global fitted parameter. The difference between the mean pairing gap and the OES gets larger as we get closer to the dripline. At the end of the thesis, a simple model has been developed which shows that when the mean-field becomes shallower the odd-even staggering of charge radii is reduced.This thesis covers results that are not included in the three published papers and some complementary works on the subject.

Abstract [sv]

Parkopplingen i atomkärnan anses vara den dominerande mångkropparskorrelationen efter kärnmedelfältet. Parkoppling i atomkärnan spelar en viktig roll i många kärnfenomen,inklusive förekomsten av en systematisk udda-jämn förskjutning (OES) av bindningsenergin.Hos svagt bundna atomkärnor däremot spelar parkopplingen en signifikant roll för stabiliteten. Det gäller alla de nyupptäckta neutronrika atomkärnor som karakteriseras aven svag bindningsenergi där således parkopplingen blir ett kritiskt fenomen. När vi lämnar stabilitetslinjen och närmar oss linjen av spontan neutronsönderfall är parkopplingeninte längre obetydlig, utan tvärtom spelar en viktig roll för stabiliteten hos atomkärnan.Dess styrka kan vara av samma storleksordning som medelfältet. I denna avhandling har vi fokuserat på parkopplingen i atomkärnor under extrema villkor i syfte att undersöka strukturen hos löst bundna atomkärnor nära linjen för neutronsönderfall; att utforska och globalt bedöma resultaten av olika parkopplingar baserad på en deltakraft (räckvidd noll) och deras effekt på löst bundna tillstånd med lågt rörelsemängdsmoment. Hur mycket kan ett täthetsberoende i parkopplingen påverka stabilitetslinjen? Beräkningarna förutsäger att ren densitetsberoende växelverkan för parkoppling, så kallad ytväxelverkan, ökar kollektiviteten i atomkärnan och ger ett större pargap för neutroner i kärnor långt ifrån stabilitetslinjen,medan densitetsberoende parkoppling påverkar inte gapet för bundna kärnor i samma omfattning.Udda-jämn-spridning av bindningsenergier har undersökts för att hitta storleken på parkopplingens gap. En 3-punktsformel Δ(3)C (1/2[B(N,Z)+B(N −2,Z)−2B(N −1,Z)]) förespråkas i denna avhandling, som vi anser vara mera lämplig för att mäta storleken på pargapet i jämn-jämna kärnor. Storleken på Δ(3)C kan vara en bra indikator på rumskorrelationen mellan två nukleoner. En-kvasipartikelenergi för de udda kärnorna, som kan approximeras med sfärisk symmetri, beräknas för att erhålla udda-jämn spridning (OES) med avseende på bindningsenergin för alla kända semi-magiska jämn-jämna kärnor. Parkopplingsstyrkan är globalt anpassat med all tillgänglig data på OES vad gäller semi-magiska kärnor med Z ≥ 8. Skillnaden mellan olika täthetsberoende parkopplingar med vår växelverkan minskar med dessa globalt anpassade parametrar. Skillnaden mellan det teoretiska genomsnittliga parkopplingsgapet och OES blir större när vi kommer närmare tröskeln för atomkärnans stabilitet. I slutet av avhandlingen har en schematisk modell utvecklats som, genom attgöra medelfältet grundare, reducerar de udda-jämnt spridda laddningsradierna. Avhandlingen innehåller dessutom resultat som inte ingår i de tre publicerade artiklarna samt några kompletterande arbeten om ämnet.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2017. 88 p.
Series
TRITA-FYS, ISSN 0280-316X ; 69
Series
Pairing correlation in atomic nuclei under extreme conditions, ISSN 0280-316X
National Category
Subatomic Physics
Research subject
Physics
Identifiers
urn:nbn:se:kth:diva-217522 (URN)978-91-7729-537-2 (ISBN)
Public defence
2017-11-24, FA32, AlbaNova Universitetscentrum, Roslagstullsbacken 21, Stockholm, 10:34 (English)
Opponent
Supervisors
Note

QC 20171114

Available from: 2017-11-14 Created: 2017-11-14 Last updated: 2017-11-14Bibliographically approved

Open Access in DiVA

fulltext(801 kB)86 downloads
File information
File name FULLTEXT01.pdfFile size 801 kBChecksum SHA-512
23eaf2e246553e647128a94b20a960f5f9890b031a8bd3e78c58de66f0fafeb88c6a268a6132c88ec90da5ff2fb94017d97d8733be184125f1161027e8ac6f8c
Type fulltextMimetype application/pdf

Other links

Publisher's full textScopusPublisher's website

Authority records BETA

Qi, Chong

Search in DiVA

By author/editor
Changizi, Sara A.Qi, Chong
By organisation
Physics
In the same journal
Physical Review C. Nuclear Physics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 86 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 108 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf