ترغب بنشر مسار تعليمي؟ اضغط هنا

Investigation of octupole vibrational states in 150Nd via inelastic proton scattering (p,pg)

126   0   0.0 ( 0 )
 نشر من قبل Sorin Pascu
 تاريخ النشر 2011
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

Octupole vibrational states were studied in the nucleus $^{150}mathrm{Nd}$ via inelastic proton scattering with $unit[10.9]{MeV}$ protons which are an excellent probe to excite natural parity states. For the first time in $^{150}mathrm{Nd}$, both the scattered protons and the $gamma$ rays were detected in coincidence giving the possibility to measure branching ratios in detail. Using the coincidence technique, the $B(E1)$ ratios of the decaying transitions for 10 octupole vibrational states and other negative-parity states to the yrast band were determined and compared to the Alaga rule. The positive and negative-parity states revealed by this experiment are compared with Interacting Boson Approximation (IBA) calculations performed in the (spdf) boson space. The calculations are found to be in good agreement with the experimental data, both for positive and negative-parity states.



قيم البحث

اقرأ أيضاً

The polarization of the secondary protons in the inelastic (p,p) reaction on the 40Ca nucleus and the relative cross sections of this reaction at 1 GeV of the initial proton energy were measured in a wide range of the scattered proton momenta (K) at lab angles theta=13.5 and theta=21.0 degrees. The final protons from the reaction were detected by means of a magnetic spectrometer equipped with multiwire proportional chamber polarimeter.
[Background:] The band structure of the negative-parity states of $^{24}$Mg has not yet been clarified. The $K^pi=0^-$, $K^pi=1^-$, and $K^pi=3^-$ bands have been suggested, but the assignments have been inconsistent between experiments and theories. [Purpose:] Negative-parity states of $^{24}$Mg are investigated by microscopic structure and reaction calculations via proton and alpha inelastic scattering to clarify the band assignment for the observed negative-parity spectra. [Method:] The structure of $^{24}$Mg was calculated using the antisymmetrized molecular dynamics~(AMD). Proton and alpha inelastic reactions were calculated using microscopic coupled-channel (MCC) calculations by folding the Melbourne $g$-matrix $NN$ interaction with the AMD densities of $^{24}$Mg. [Results:] The member states of the $K^pi=0^+$, $K^pi=2^+$, $K^pi=0^-$, $K^pi=1^-$, and $K^pi=3^-$ bands of $^{24}$Mg were obtained through the AMD result. In the MCC+AMD results for proton and alpha elastic and inelastic cross sections, reasonable agreements were obtained with existing data, except in the case of the $4^+_1$ state. [Conclusions:] The $3^-$ state of the $K^pi=3^-$ band and the $1^-$ and $3^-$ states of the $K^pi=0^-$ bands were assigned to the $3^-_1$(7.62 MeV), $1^-_1$(7.56 MeV), and $3^-_2$(8.36 MeV) states, respectively. The present AMD calculation is the first microscopic structure calculation to reproduce the energy ordering of the $K^pi=0^-$, $K^pi=1^-$, and $K^pi=3^-$ bands of $^{24}$Mg.
91 - Junki Tanaka 2017
Proton inelastic scattering off a neutron halo nucleus, 11Li, has been studied in inverse kinematics at the IRIS facility at TRIUMF. The aim was to establish a soft dipole resonance and to obtain its dipole strength. Using a high quality 66 MeV 11Li beam, a strongly populated excited state in 11Li was observed at Ex=0.80 +/- 0.02 MeV with a width of 1.15 +/- 0.06 MeV. A DWBA (distorted-wave Born approximation) analysis of the measured differential cross section with isoscalar macroscopic form factors leads to conclude that this observed state is excited in an electric dipole (E1) transition. Under the assumption of isoscalar E1 transition, the strength is evaluated to be extremely large amounting to 600 to 2000 Weisskopf units, exhausting 4% to 14% of the isoscalar E1 energy-weighted sum rule (EWSR) value. The large observed strength originates from the halo and is consistent with the simple di-neutron model of 11Li halo.
We performed a high resolution study of $0^{+}$ states in $^{134}$Ba using the $^{136}$Ba($p,t$) two-neutron transfer reaction. Our experiment shows a significant portion of the $L = 0$ pair-transfer strength concentrated at excited $0^+$ levels in $ ^{134}$Ba. Potential implications in the context of $^{136}$Xe $to$ $^{136}$Ba neutrinoless double beta decay matrix element calculations are briefly discussed.
112 - J. Hu , J.J. He , S.W. Xu 2010
Properties of proton resonances in $^{18}$Ne have been investigated efficiently by utilizing a technique of proton resonant elastic scattering with a $^{17}$F radioactive ion (RI) beam and a thick proton target. A 4.22~MeV/nucleon $^{17}$F RI beam wa s produced via a projectile-fragmentation reaction, and subsequently separated by a Radioactive Ion Beam Line in Lanzhou ({tt RIBLL}). Energy spectra of the recoiled protons were measured by two sets of $Delta$E-E silicon telescope at center-of-mass scattering angles of $theta_{c.m.}$$approx$175${^circ}$$pm$5${^circ}$, $theta_{c.m.}$$approx$152${^circ}$$pm$8${^circ}$, respectively. Several proton resonances in $^{18}$Ne were observed, and their resonant parameters have been determined by an $R$-matrix analysis of the differential cross sections in combination with the previous results. The resonant parameters are related to the reaction-rate calculation of the stellar $^{14}$O($alpha$,$p$)$^{17}$F reaction, which was thought to be the breakout reaction from the hot CNO cycles into the $rp$-process in x-ray bursters. Here, $J^pi$=(3$^-$, 2$^-$) are tentatively assigned to the 6.15-MeV state which was thought the key 1$^-$ state previously. In addition, a doublet structure at 7.05 MeV are tentatively identified, and its contribution to the resonant reaction rate of $^{14}$O($alpha$,$p$)$^{17}$F could be enhanced by at least factors of about 4$sim$6 in comparison with the previous estimation involving only a singlet. The present calculated resonant rates are much larger than those previous values, and it may imply that this breakout reaction could play a crucial role under x-ray bursters conditions.
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