Nonlinear Higher Quasiparticle Random Phase Approximation

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21670%2F17%3A00318848" target="_blank" >RIV/68407700:21670/17:00318848 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1063/1.5007646" target="_blank" >http://dx.doi.org/10.1063/1.5007646</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/1.5007646" target="_blank" >10.1063/1.5007646</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Nonlinear Higher Quasiparticle Random Phase Approximation

Popis výsledku v původním jazyce

We develop a new approach to describe nuclear states of multiphonon origin, motivated by the necessity for a more accurate description of matrix elements of neutrinoless double-beta decay. Our approach is an extension of the Quasiparticle Random Phase Approximation (QRPA), in which nonlinear phonon operators play an essential role. Before applying the nonlinear higher QRPA (nhQRPA) to realistic problems, we test its efficiency with exactly solvable models. The first considered model is equivalent to a harmonic oscillator. The nhQRPA solutions follow from the standard QRPA equation, but for nonlinear phonon operators defined for each individual excited state separately. The second exactly solvable model is the proton-neutron Lipkin model that describes successfully not only energy spectrum of nuclei, but also beta-decay transitions. Again, we reproduce exactly the numerical solutions in the nhQRPA framework. We show in particular that truncation of the nonlinear phonon operators leads to an approximation similar to the self-consistent second QRPA, given the phonon operators are defined with a constant term. The test results demonstrate that the proposed nhQRPA is a promising tool for a realistic calculation of energy spectra and nuclear transitions.

Název v anglickém jazyce

Nonlinear Higher Quasiparticle Random Phase Approximation

Popis výsledku anglicky

We develop a new approach to describe nuclear states of multiphonon origin, motivated by the necessity for a more accurate description of matrix elements of neutrinoless double-beta decay. Our approach is an extension of the Quasiparticle Random Phase Approximation (QRPA), in which nonlinear phonon operators play an essential role. Before applying the nonlinear higher QRPA (nhQRPA) to realistic problems, we test its efficiency with exactly solvable models. The first considered model is equivalent to a harmonic oscillator. The nhQRPA solutions follow from the standard QRPA equation, but for nonlinear phonon operators defined for each individual excited state separately. The second exactly solvable model is the proton-neutron Lipkin model that describes successfully not only energy spectrum of nuclei, but also beta-decay transitions. Again, we reproduce exactly the numerical solutions in the nhQRPA framework. We show in particular that truncation of the nonlinear phonon operators leads to an approximation similar to the self-consistent second QRPA, given the phonon operators are defined with a constant term. The test results demonstrate that the proposed nhQRPA is a promising tool for a realistic calculation of energy spectra and nuclear transitions.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

10304 - Nuclear physics

Projekt

<a href="/cs/project/EF16_013%2F0001733" target="_blank" >EF16_013/0001733: Podzemní laboratoř LSM - česká účast ve výzkumné infrastruktuře evropského významu</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Workshop on Calculation of Double-Beta-Decay Matrix Elements (MEDEX´17)

ISBN

978-0-7354-1577-5

ISSN

0094-243X

e-ISSN

—

Počet stran výsledku

5

Strana od-do

—

Název nakladatele

AIP Conference Proceedings

Místo vydání

New York

Místo konání akce

Praha

Datum konání akce

29. 5. 2017

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

000417388100021