Search arXivSearch

arXiv · nucl-ex/0505007

Investigation of the 6He cluster structures

Abstract

The 4He+2n and t+t clustering of the 6He ground state were investigated by means of the transfer reaction 6He(p,t)4He at 25 MeV/nucleon. The experiment was performed in inverse kinematics at GANIL with the SPEG spectrometer coupled to the MUST array. Experimental data for the transfer reaction were analyzed by a DWBA calculation including the two neutrons and the triton transfer. The couplings to the 6He --> 4He + 2n breakup channels were taken into account with a polarization potential deduced from a coupled-discretized-continuum channels analysis of the 6He+1H elastic scattering measured at the same time. The influence on the calculations of the 4He+t exit potential and of the triton sequential transfer is discussed. The final calculation gives a spectroscopic factor close to one for the 4He+2n configuration as expected. The spectroscopic factor obtained for the t+t configuration is much smaller than the theoretical predictions.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

L. Giot, P. Roussel-Chomaz, C. E. Demonchy, W. Mittig, H. Savajols, N. Alamanos, F. Auger, A. Gillibert, C. Jouanne, V. Lapoux, L. Nalpas, E. C. Pollacco, J. L. Sida, F. Skaza, M. D. Cortina-Gil, J. Fernandez-Vasquez, R. S. Mackintosh, A. Pakou, S. Pita, A. Rodin, S. Stepantsov, G. M. Ter Akopian, K. Rusek, I. J. Thompson, R. Wolski. 2005-05-04. Investigation of the 6He cluster structures. https://doi.org/10.1103/physrevc.71.064311

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Isospin-symmetry violation - kaons and beyond (ISO-BREAK 25: summary and outlook)

This report summarizes the presentations and discussions during the ISO-BREAK 25 Workshop ``Isospin symmetry violation: kaons and beyond'', which was held at Jan Kochanowski University in Kielce on October 23--25, 2025. We address the current status of the isospin-symmetry breaking discovered by NA61/SHINE in nucleus--nucleus collisions at the CERN SPS, its confirmation by other experiments and studies in \ee and deep inelastic scattering. In addition, we discuss the theoretical status as well as we outline experimental and theoretical priorities towards understanding this currently unexplained phenomenon.

nucl-ex

Probing the $^{12}$C+$^{12}$C fusion reaction via zero-degree spectator measurement in the $^{12}$C($^{14}$N,$αd$)$^{20}$Ne quasi-free reaction

The 12C+12C fusion reaction is a key physical process in stellar evolution and supernova explosions. It not only determines the late evolutionary fate of massive stars but also directly influences the critical conditions for triggering Type Ia supernovae in accreting white dwarfs. In this work, the THM was employed to investigate the 12C(12C,a0)20Ne reaction channel of the 12C+12C fusion process, using 14N as the Trojan horse nucleus. Telescope detectors were placed at 0 and 15 deg. to design two experimental configurations covering the forward-angle regions where spectator particles are most likely to emerge. By applying the DWBA, two sets of astrophysical S*(E) factors for the two-body reaction 12C(12C,a0)20Ne were extracted from the three-body reaction 12C(14N,da0)20Ne and normalized to existing experimental data. The results show that, limited by the overall experimental resolution, the present study cannot resolve fine resonance structures. Within the astrophysical energy region of 0.5-2 MeV, the extracted S*(E) factor exhibits an increasing trend toward lower energies. The S*(E) factor obtained with the 0-deg configuration shows a flatter trend than that obtained with the 15-deg configuration. Supported by the quasi-free reaction simulation results, the divergence between the two data sets may reflect a combination of experimental acceptance effects, finite detector resolution, and possible differences in the relative contributions of reaction mechanisms. This study provides a systematic examination of the experimental design, quasi-free event selection strategy, and interpretation of the underlying physical mechanisms, serving as a useful reference for understanding the role of the 12C+12C fusion reaction in astrophysical processes.

nucl-ex

Mean-$p_T$ fluctuations in Au+Au collisions at $\sqrt{s_{\rm NN}}=3.0$--$19.6$ GeV within JAM2

Event-by-event mean-$p_T$ fluctuations probe initial-state fluctuations and their evolution through the dynamics of heavy-ion collisions. We study second-order mean-$p_T$ fluctuations in Au+Au collisions at $\sqrt{s_{\rm NN}}=3.0$--$19.6$ GeV using JAM2 in the RQMDv mean-field mode with the MH2 parameterization. The model qualitatively reproduces the measured identified-particle $p_T$ spectra, providing a single-particle baseline for the fluctuation analysis. The scaled fluctuation $k_2$ decreases with increasing $\langle N_{\rm part}\rangle$ and shows broad agreement with the available measurements at 7.7--19.6 GeV, whereas its calculated centrality dependence is stronger than that in the data at 3.0--4.5 GeV. For the combined proton-plus-antiproton sample, the unnormalized correlator $\langle c_2\rangle$ is positive and larger than that for charged pions. The charged-pion correlator $\langle c_2\rangle$ is negative or consistent with zero over most centrality intervals at 3.0 and 3.5 GeV, becomes weakly positive at 4.5 GeV, and remains positive at higher energies. Its energy evolution resembles the change in the reaction-plane elliptic flow, but this comparison does not establish a common microscopic origin. These calculations provide species-dependent predictions within a transport model without an explicit partonic stage. Isolating the contributions of mean fields, rescattering, and spectator interactions requires controlled variations of the transport dynamics.

nucl-ex