Quest for superradiance in atomic nuclei

Kravvaris, Konstantinos; Volya, Alexander

doi:10.1063/1.5016135

Cited by 7 publications

(2 citation statements)

References 42 publications

(76 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In theory there are two states predicted at 6.9 and 7.9 MeV that are strongly coupled and share nearly full alpha strength in ℓ = 1 n = 4 channel. Strong coupling to a decay channel is known to cause a super-radiance mechanism in overlapping resonances leading to full decay width being absorbed by one of the states [46,47]. Thus the super-radiant 1 − is likely the state seen in experiments and redistribution of the width that this theory is unable to describe is not surprising.…”

Section: Theorymentioning

confidence: 99%

The Lowest Broad Alpha Cluster Resonances in $^{19}$F

Volya,

Goldberg,

Nurmukhanbetova

et al. 2021

Preprint

View full text Add to dashboard Cite

Background: There is a deep astrophysical interest in the structure of 19 F states close to the alpha decay threshold. The nuclear structure of these states is important for understanding of the development of α clustering in the 20 Ne region. Emergence of clustered states and generally states that favor coupling to reaction channels near the corresponding decay thresholds is currently of special interest in theoretical physics. The only detailed high energy resolution 15 N(α,α) work was made in 1961, and a complete analysis of these data has never been made.Purpose: To identify the parameters of broad low spin states in 19 F near the α decay threshold, to present a theoretical study of these states and to assess the current state of the theoretical methods.Method: Excitation function for 15 N(α,α) elastic scattering was measured by the TTIK method. These new data together with old, high energy resolution data, were analyzed using the R matrix approach. 19 F nuclear structure was calculated using configuration interaction methods with the recently developed effective interaction Hamiltonian. Results:The parameters of broad low spin ℓ = 0 and 1 relative partial wave resonances close to the α decay threshold in 19 F were identified. Detailed theoretical analysis was carried out identifying all states coupled to the ℓ = 0 and 1 alpha cluster channels. Considering hierarchy of states with different harmonic oscillator shell excitations allows to evaluate coupling to the alpha channels with different number of nodes in the relative wave function and helps to explain the distribution of the clustering strength and emergence of broad clustering resonances. Comparison of clustering in 20 Ne into 16 O+α and consideration of spin-orbit splitting of the 15 N+α channel provides additional evidence.Conclusions: Detailed analysis of new and old experimental data allows to identify a series of α clustering resonances in 19 F and to assess the distribution of the clustering strength which is of importance to questions of astrophysics and for theoretical understanding of many-body physics and emergence of clustering in loosely bound or unstable nuclei. Progress has been made in theoretical understanding of the origins of clustering and questions for future theoretical and experimental research are identified.

show abstract

Section: Theorymentioning

confidence: 99%

The Lowest Broad Alpha Cluster Resonances in $^{19}$F

Volya,

Goldberg,

Nurmukhanbetova

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…Some states become more aligned along the dominant channels and thus become superradiant, while others decouple from the decay and become trapped. The term superradiance originates from the coherent radiation phenomenon by gas atoms coupled through a common radiation field [14][15][16] is well known in quantum optics and has been observed in some atomic systems, however, its manifestation in nuclear physics is not yet clear 17 .…”

mentioning

confidence: 99%

Superradiance in alpha clustered mirror nuclei

et al. 2022

Self Cite

View full text Add to dashboard Cite

Resonances in unstable quantum systems are radiating states that despite decaying overall normalization have a well-defined structure which is being balanced by outgoing radiation. Such an interplay between outgoing wave and internal quantum many-body dynamics leads to several unique effects. One of those is known as superradiance, or alignment, where due to decay or virtual coupling to the continuum the states undergo restructuring so that their wave functions align towards the decay channels thus facilitating the decay. This effect is well understood theoretically and is closely related to the fundamental properties of reaction physics. Direct observation of superradiance in open quantum many-body systems is difficult because it is hard to find identical complex quantum systems that are different only in their coupling to the continuum of reaction states describing the decay. Here we report this phenomenon in alpha cluster decays of mirror nuclei 18O and 18Ne.

show abstract