ترغب بنشر مسار تعليمي؟ اضغط هنا

Improved di-neutron cluster model for 6He scattering

58   0   0.0 ( 0 )
 نشر من قبل Antonio Moro
 تاريخ النشر 2007
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

The structure of the three-body Borromean nucleus 6He is approximated by a two-body di-neutron cluster model. The binding energy of the 2n-alpha system is determined to obtain a correct description of the 2n-alpha coordinate, as given by a realistic three-body model calculation. The model is applied to describe the break-up effects in elastic scattering of 6He on several targets, for which experimental data exist. We show that an adequate description of the di-neutron-core degree of freedom permits a fairly accurate description of the elastic scattering of 6He on different targets.



قيم البحث

اقرأ أيضاً

Cross sections of $^{120}$Sn($alpha$,$alpha$)$^{120}$Sn elastic scattering have been extracted from the $alpha$ particle beam contamination of a recent $^{120}$Sn($^6$He,$^6$He)$^{120}$Sn experiment. Both reactions are analyzed using systematic doubl e folding potentials in the real part and smoothly varying Woods-Saxon potentials in the imaginary part. The potential extracted from the $^{120}$Sn($^6$He,$^6$He)$^{120}$Sn data may be used as the basis for the construction of a simple global $^6$He optical potential. The comparison of the $^6$He and $alpha$ data shows that the halo nature of the $^6$He nucleus leads to a clear signature in the reflexion coefficients $eta_L$: the relevant angular momenta $L$ with $eta_L gg 0$ and $eta_L ll 1$ are shifted to larger $L$ with a broader distribution. This signature is not present in the $alpha$ scattering data and can thus be used as a new criterion for the definition of a halo nucleus.
Vector analyzing power for the proton-6He elastic scattering at 71 MeV/nucleon has been measured for the first time, with a newly developed polarized proton solid target working at low magnetic field of 0.09 T. The results are found to be incompatibl e with a t-matrix folding model prediction. Comparisons of the data with g-matrix folding analyses clearly show that the vector analyzing power is sensitive to the nuclear structure model used in the reaction analysis. The alpha-core distribution in 6He is suggested to be a possible key to understand the nuclear structure sensitivity.
The first direct mass-measurement of $^{6}$He has been performed with the TITAN Penning trap mass spectrometer at the ISAC facility. In addition, the mass of $^{8}$He was determined with improved precision over our previous measurement. The obtained masses are $m$($^{6}$He) = 6.018 885 883(57) u and $m$($^{8}$He) = 8.033 934 44(11) u. The $^{6}$He value shows a deviation from the literature of 4$sigma$. With these new mass values and the previously measured atomic isotope shifts we obtain charge radii of 2.060(8) fm and 1.959(16) fm for $^{6}$He and $^{8}$He respectively. We present a detailed comparison to nuclear theory for $^6$He, including new hyperspherical harmonics results. A correlation plot of the point-proton radius with the two-neutron separation energy demonstrates clearly the importance of three-nucleon forces.
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.
271 - Chen Wu , Ru-Keng Su 2008
A new improved quark mass density-dependent model including u, d quarks, $sigma$ mesons, $omega$ mesons and $rho$ mesons is presented. Employing this model, the properties of nuclear matter, neutron matter and neutron star are studied. We find that i t can describe above properties successfully. The results given by the new improved quark mass density- dependent model and by the quark meson coupling model are compared.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا