Double Beta Decay of 48Ca within EMPM and STDA methods

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F25%3A00645749" target="_blank" >RIV/61389005:_____/25:00645749 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.epj-conferences.org/articles/epjconf/abs/2025/27/epjconf_NuclearPhysics2025_01030/epjconf_NuclearPhysics2025_01030.html" target="_blank" >https://www.epj-conferences.org/articles/epjconf/abs/2025/27/epjconf_NuclearPhysics2025_01030/epjconf_NuclearPhysics2025_01030.html</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/epjconf/202534201030" target="_blank" >10.1051/epjconf/202534201030</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Double Beta Decay of 48Ca within EMPM and STDA methods

Popis výsledku v původním jazyce

The calculation of nuclear matrix elements (NMEs) for neutrinoless double-beta decay (0vßß) remains a major theoretical challenge in nuclear physics, as NMEs for this process cannot be accessed directly through experiment. Cur­rent nuclear structure models yield significantly different predictions for 0 vßß NMEs, making it essential to validate theoretical approaches using observables that are experimentally known. In contrast, two-neutrino double-beta decay (2vßß) has been measured in eleven isotopes, providing a valuable benchmark for testing the reliability of nuclear many-body methods.nnIn this work, we compute the 2vßß decay half-life of 48Ca using the Second Tamm-Dancoff Approximation (STDA) and the Equation of Motion Phonon Method (EMPM). By extending EMPM up to two-phonon configurations, we confirm that the two approaches yield practically identical numerical results, providing a strong internal consistency check. In addition, we study the de­pendence of the 2 vßß NME on the Gamow-Teller and Fermi contributions, on the particle-hole interaction strength parameter gph. Accurately reproducing the experimental 2 vßß half-life requires a substantial quenching of the axial-vector coupling constant gA. Furthermore, our theoretical framework outlines a strat­egy to mitigate this quenching issue by systematically including more complex configurations in the nuclear wave function.

Název v anglickém jazyce

Double Beta Decay of 48Ca within EMPM and STDA methods

Popis výsledku anglicky

The calculation of nuclear matrix elements (NMEs) for neutrinoless double-beta decay (0vßß) remains a major theoretical challenge in nuclear physics, as NMEs for this process cannot be accessed directly through experiment. Cur­rent nuclear structure models yield significantly different predictions for 0 vßß NMEs, making it essential to validate theoretical approaches using observables that are experimentally known. In contrast, two-neutrino double-beta decay (2vßß) has been measured in eleven isotopes, providing a valuable benchmark for testing the reliability of nuclear many-body methods.nnIn this work, we compute the 2vßß decay half-life of 48Ca using the Second Tamm-Dancoff Approximation (STDA) and the Equation of Motion Phonon Method (EMPM). By extending EMPM up to two-phonon configurations, we confirm that the two approaches yield practically identical numerical results, providing a strong internal consistency check. In addition, we study the de­pendence of the 2 vßß NME on the Gamow-Teller and Fermi contributions, on the particle-hole interaction strength parameter gph. Accurately reproducing the experimental 2 vßß half-life requires a substantial quenching of the axial-vector coupling constant gA. Furthermore, our theoretical framework outlines a strat­egy to mitigate this quenching issue by systematically including more complex configurations in the nuclear wave function.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

10301 - Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)

Projekt

<a href="/cs/project/GA24-10180S" target="_blank" >GA24-10180S: Zkoumaní vlastností neutrin prostřednictvím dvojitého beta rozpadu: Souhra teorie a experimentu</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název statě ve sborníku

EPJ Web of Conferences

ISBN

—

ISSN

2100-014X

e-ISSN

—

Počet stran výsledku

8

Strana od-do

01030

Název nakladatele

EDP sciences

Místo vydání

Les Ulis

Místo konání akce

Ischia

Datum konání akce

19. 5. 2025

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

—