New candidate for an alpha cluster condensed state in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mmultiscripts><mml:mi mathvariant="normal">O</mml:mi><mml:mprescripts /><mml:none /><mml:mn>16</mml:mn></mml:mmultiscripts><mml:mo stretchy="false">(</mml:mo><mml:mi>α</mml:mi><mml:mo>,</mml:mo><mml:msup><mml:mi>α</mml:mi><mml:mo>′</mml:mo></mml:msup><mml:mo stretchy="false">)</mml:mo></mml:math> at 400 MeV

Wakasa, T.; Ihara, Eikichi; Fujita, K.; Funaki, Y.; Hatanaka, K.; Horiuchi, Hisashi; Itoh, Masatoshi; Kamiya, J.; Röpke, G.; Sakaguchi, H.; Sakamoto, N.; Sakemi, Y.; Schuck, Peter; Shimizu, Y.; Takashina, Masaaki; Terashima, S.; Tohsaki, Akihiro; Uchida, M.; Yoshida, H. P.; Yosoi, M.

doi:10.1016/j.physletb.2007.08.016

Cited by 97 publications

(66 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The enhancement of the transition strength would correspond to the development of such cluster structure. In this respect, gas-like two α states around an 16 O core in 24 Mg have been investigated both theoretically [15,[17][18][19] and experimentally [16,20,21].…”

mentioning

confidence: 99%

Search for three-αstates around an16O core in28Si

et al. 2012

View full text Add to dashboard Cite

We investigate the existence of weakly coupled gas-like states comprised of three α particles around an 16 O core in 28 Si. We calculate the excited states in 28 Si using the multi-configuration mixing method based on the 16 O + 3α cluster model. We also include the 16 O + 12 C and 24 Mg + α basis wave functions prepared by the generator coordinate method. To identify the gas-like states, we calculate the isoscalar monopole transition strengths and the overlap of the obtained states with the geometrical cluster wave function and the TohsakiHoriuchi-Schuck-Röpke (THSR) wave function. The results show that the obtained fourth and twelfth states significantly overlap with the THSR wave function. These two states clearly coexist with the 16 O + 12 C cluster states, emerging at similar energies. The calculated isoscalar monopole strengths between those two states are significantly large, indicating that the states are members of the excitation mode. Furthermore, the calculated root-mean-squared (RMS) radii for these states also suggest that a layer of gas-like three α particles could exist around the surface of the 16 O core, which can be described as a "two-dimensional gas" in the intermediate state before the Hoyle-like three α states emerge. 21.60.Gx,27.20.+n,27.30.+t The investigations of excited states in light-mass nuclei provide a good opportunity to study the rich variety of nuclear structures of quantum many-body systems. One of these states is the well known Hoyle state in 12 C * [1]. The Hoyle state is the second 0 + state in 12 C * , with an excitation energy of 7.65 MeV, just above the 3 α decay threshold energy. Many theoretical attempts have been performed to reproduce its energy and geometrical properties. It was found, that it is difficult to reproduce those values by calculations based only on the shell model. On the other hand, the microscopic three α cluster models successfully describe the properties of the Hoyle state (such as the observed α-decay width) and indicate that the three α state develops well in the 0 + 2 state [2,3]. Recent calculations, using the α cluster model suggest that in the Hoyle state, the three "gas-like" α particles are weakly coupled with each other at near the three α-decay threshold energy [4,5]. Based on this picture, the Tohsaki-HoriuchiSchuck-Röpke (THSR) wave function was proposed. This wave function describes the α particles as independent, with their center-of-mass motion, in the same 0S state of the harmonic oscillator, having a large oscillator parameter. Using this wave function, Tohsaki et al. proposed the extremely large RMS nuclear radius for the 0 + 2 state in 12 C [4]. Those studies have triggered interest in whether such gaslike states exist in heavier-mass nuclei. Funaki et al. searched for gas-like four α states in 16 O * using the microscopic α cluster model coupled with the THSR wave function [6,7]. In this connection, the existence of weakly coupled gas-like α cluster states around a core has been recently suggested [8][9][10][11][12]. To study...

show abstract

mentioning

confidence: 99%

Search for three-αstates around an16O core in28Si

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Another example is 10 Be; although all the low-lying states of 10 Be have been found to be well described by the combination of three molecular-orbits for the two valence neutrons around two α-clusters [9], the α+t+t cluster structure is found to coexist with the α+α+n+n structure around E x = 15 MeV, close to the corresponding threshold [10]. The existence of 7 Li+t cluster configuration of 10 Be has been reported in the recent experiment with 8 Li(d, t) 7 Li reaction [11,12], and since the 7 Li nucleus is well-known to be described as α+t cluster structure, the resonance state is considered to have the α+t+t cluster configuration. This is one of the first example that completely different cluster configurations of triton-type (α + t + t) and α type (α+α+n+n) coexist in a single nucleus around the same energy region.…”

Section: Introductionmentioning

confidence: 98%

“…The state is well expressed by THSR (Tohsaki Horiuchi Schuck Röpke) wave function, where all of the α-clusters occupy the same 0s-orbital with a spatially extended distribution [2]. In addition, a candidate for the gas-like state of 4α clusters around the threshold energy in 16 O has been studied both by theoretical and experimental approaches [1,3,7].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Three-triton states in9Li

et al. 2011

View full text Add to dashboard Cite

We focus on a characteristic non-α cluster structure in light neutron-rich nuclei; three triton structure in 9 Li. This is an analogy to the case of three α state in 12 C (Hoyle state). The α clusters behave as bosons, however tritons have Fermionic nature, and how the three cluster structure is different from 12 C is an intriguing problem. For this purpose, we introduce three triton wave functions. In addition, α+t+n+n wave functions are prepared to describe other low-lying states of 9 Li, and the coupling effect between them is taken into account. The states with dominantly the three triton components appear below the three triton threshold energy, where three triton correlation is important, however the root mean square radius is not enhanced contrary to the α gas states in 12 C and 16 O.

show abstract

“…[45], and from Ref. [46] for the 0 + 4 state. The assignments with experiment are tentative, see, however, detailed discussion in the text.…”

mentioning

confidence: 99%

Alpha particle condensation in nuclear systems

Funaki¹

2006

AIP Conference Proceedings

Self Cite

View full text Add to dashboard Cite

The onset of quartetting, i.e. α-particle condensation, in symmetric nuclear matter is studied with the help of an in-medium modified four nucleon equation. It is found that at very low density quartetting wins over pairing, because of the strong binding of the α-particles. The critical temperature can reach values up to around 6 MeV. Also the disappearance of α-particles with increasing density, i.e. the Mott transition, is investigated. In finite nuclei the Hoyle state, that is the 0 2 + of 12 C, is identified as an "α-particle condensate" state. It is conjectured that such states also exist in heavier nα-nuclei, like 16 O, 20 Ne, etc. For instance the 6-th 0 + state of 16 O at 15.1 MeV is identified from a theoretical analysis as being a strong candidate for an α condensate state. Exploratory calculations are performed for the density dependence of the α condensate fraction at zero temperature to address the suppression of the four-particle condensate below nuclear-matter density. Possible quartet condensation in other systems is discussed briefly.

show abstract

New candidate for an alpha cluster condensed state in O16(α,α′) at 400 MeV

Cited by 97 publications

References 30 publications

Search for three-αstates around an16O core in28Si

Search for three-αstates around an16O core in28Si

Three-triton states in9Li

Alpha particle condensation in nuclear systems

Contact Info

Product

Resources

About