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تسجيل مستخدم جديدExploring two-neutron halo formation in the ground-state of $^{29}$F within a three-body model
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Background$colon$ The $^{29}$F system is located at the lower-N boundary of the island of inversion and is an exotic, weakly bound system. Little is known about this system beyond its two-neutron separation energy ($S_{2n}$) with large uncertainties. A similar situation is found for the low-lying spectrum of its unbound binary subsystem $^{28}$F. Purpose$colon$ To investigate the configuration mixing, matter radius and neutron-neutron correlations in the ground state of $^{29}$F within a three-body model, exploring the possibility of $^{29}$F to be a two-neutron halo nucleus. Method$colon$ The $^{29}$F ground-state wave function is built within the hyperspherical formalism by using an analytical transformed harmonic oscillator basis. The Gogny-Pires-Tourreil (GPT) nn interaction with central, spin-orbit and tensor terms is employed in the present calculations, together with different core$+n$ potentials constrained by the available experimental information on $^{28}$F. Results$colon$ The $^{29}$F ground-state configuration mixing and its matter radius are computed for different choices of the $^{28}$F structure and $S_{2n}$ value. The admixture of d-waves with pf components are found to play an important role, favoring the dominance of dineutron configurations in the wave function. Our computed radii show a mild sensitivity to the $^{27}$F$+n$ potential and $S_{2n}$ values. The relative increase of the matter radius with respect to the $^{27}$F core lies in the range 0.1-0.4 fm depending upon these choices. Conclusions$colon$ Our three-body results for $^{29}$F indicate the presence of a moderate halo structure in its ground state, which is enhanced by larger intruder components. This finding calls for an experimental confirmation.
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We report the measurement of reaction cross sections ($sigma_R^{rm ex}$) of $^{27,29}$F with a carbon target at RIKEN. The unexpectedly large $sigma_R^{rm ex}$ and derived matter radius identify $^{29}$F as the heaviest two-neutron Borromean halo to
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We investigate low-lying bound states of the neutron-rich nucleus ${}^{15}$B by assuming it is a three-body system made of an inert core ${}^{13}$B and two valence neutrons. The three-body wave functions are obtained using the Faddeev formalism. Spec
ial attention is paid to the excited state at $3.48(6)$ MeV observed in the ${}^{13}text{C}({}^{14}text{C},{}^{12}text{N}){}^{15}text{B}$ reaction, whose properties are less clear theoretically. In our three-body model, besides the ground state $3/2_1^-$, a second $3/2_2^-$ state is discovered at around $3.61$ MeV, which might be identified with the excited state observed at $3.48(6)$ MeV. We study this $3/2_2^-$ state in detail, which turns out to be a two-neutron halo state with a large matter radius $r_text{m}approx 4.770$ fm.
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