Related papers: Decay and structure of the Hoyle state
The spatial structure of the lowest 0$_1^+$, 0$_2^+$, 2$_1^+$ and 2$_2^+$ states of the $^{12}$C nucleus is studied within the 3$\alpha$ model with the Buck, Friedrich, and Wheatley $\alpha \alpha$ potential with Pauli forbidden states in…
Background: The triple-alpha process is a vital reaction in nuclear astrophysics, characterized by two consecutive reactions [$2\alpha\leftrightarrows{^{8}\rm{Be}}(\alpha,\gamma){^{12}\rm{C}}$] that drive carbon formation. The second…
Background: The structure of the Hoyle state, a highly $\alpha$-clustered state at 7.65 MeV in $^{12}\mathrm{C}$, has long been the subject of debate. Understanding if the system comprises of three weakly-interacting $\alpha$-particles in…
In the context of the search for triples of relativistic $\alpha$-particles in the Hoyle state, the analysis of available data on the dissociation of the nuclei ${}^{12}$C, ${}^{16}$O and ${}^{22}$Ne in the nuclear emulsion was carried out.…
Our present understanding of the structure of the Hoyle state in $^{12}$C and other near-threshold states in $\alpha$-conjugate nuclei is reviewed in the framework of the $\alpha$-condensate model. The $^{12}$C Hoyle state, in particular,…
We investigate geometric configurations of $\alpha$ ($^4$He nucleus) clusters in the second $J^\pi=2^+$ state of $^{12}$C, which has been discussed as a rotational band member of the second $0^+$ state, the Hoyle state. The ground and…
The present understanding of the structure of the Hoyle state in 12C is reviewed. Most of the theoretical approaches to the Hoyle state are shortly summarized. The corresponding results are analyzed with respect to whether they give…
The second 2+ state of 12C, predicted over fifty years ago as an excitation of the Hoyle state, has been unambiguously identified using the 12C(g,a_0)8Be reaction. The alpha particles produced by the photodisintegration of 12C were detected…
The energy level structure of ${}^{12}$C nucleus at a few MeV above the three-$\alpha$ threshold is still unsatisfactory known. For instance, most microscopic calculations predicted that there exist one $0^+$-state in this energy region…
The electric multipole strength distributions for transitions from the ${}^{12}\mathrm{C}(0_1^+)$ ground state to $3\alpha$ ($0^+$, $1^-$, $2^+$, and $3^-$) continuum states are studied in terms of $3\alpha$ model. Several sets of the…
The Hoyle state and other resonances in the continuum above the 3 alpha threshold in 12C are studied in a microscopic cluster model. Whereas the Hoyle state is a very sharp resonance and can be treated reasonably well in bound state…
The hyperspherical adiabatic expansion is combined with complex scaling and used to calculate the energy distributions of the particles arising from three-body decaying low-lying $^{12}$C resonances. The large distance continuum properties…
In order to discuss the spatial extention of the second 0+ state of 12C (Hoyle state), we analyze the inelastic form factor of electron scattering to the Hoyle state, which our 3 alpha condensate wave function reproduces very well like…
We use a sequential $R$-matrix model to describe the breakup of the Hoyle state into three $\alpha$ particles via the ground state of $^8\mathrm{Be}$. It is shown that even in a sequential picture, features resembling a direct breakup…
$^3$He+$^{12}$C scattering is studied in a coupled channel method by using a double folding model with microscopic wave functions of $^{12}$C. Experimental angular distributions in elastic and inelastic scattering to the $2^+$ (4.44 MeV),…
We compute energy distributions of three $\alpha$-particles emerging from the decay of $^{12}$C resonances by means of the hyperspherical adiabatic expansion method combined with complex scaling. The large distance continuum properties of…
An excited state of $^{12}$C having excitation energy E$_x \sim$ 9.65 $\pm$ 0.02 MeV and width (FWHM) $\sim607\pm$ 55 keV, which decays to three $ \alpha $-particles via Hoyle state ($E_x \sim$ 7.65 MeV), has been directly identified for…
We compute energy distributions of three particles emerging from decaying many-body resonances. We reproduce the measured energy distributions from decays of two archetypal states chosen as the lowest $0^{+}$ and $1^{+}$-resonances in…
The excited states in ${^{12}{\rm C}}$ are investigated by using an extended version of the so-called Tohsaki-Horiuchi- Schuck-R\"opke (THSR) wave function, where both the $3\alpha$ condensate and ${^{8}{\rm Be}} + \alpha$ cluster…
Production of $\alpha$-particle triples in the Hoyle state (HS) in dissociation of ${}^{12}$C nuclei at 3.65 and 0.42 $A$ GeV in nuclear track emulsion is revealed by the invariant mass approach. Contribution of the HS to the dissociation…