ترغب بنشر مسار تعليمي؟ اضغط هنا

Refinement of the $n-alpha$ and $p-alpha$ fish-bone potential

109   0   0.0 ( 0 )
 نشر من قبل Zoltan Papp
 تاريخ النشر 2012
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

The fishbone potential of composite particles simulates the Pauli effect by nonlocal terms. We determine the $n-alpha$ and $p-alpha$ fish-bone potential by simultaneously fitting to the experimental phase shifts. We found that with a double Gaussian parametrization of the local potential can describe the $n-alpha$ and $p-alpha$ phase shifts for all partial waves.



قيم البحث

اقرأ أيضاً

The fishbone potential of composite particles simulates the Pauli effect by nonlocal terms. We determine the $alpha-alpha$ fishbone potential by simultaneously fitting to two-$alpha$ resonance energies, experimental phase shifts and three-$alpha$ bin ding energies. We found that essentially a simple gaussian can provide a good description of two-$alpha$ and three-$alpha$ experimental data without invoking three-body potentials.
A large number of $(alpha,p)$ and $(alpha,n)$ reactions are known to play a fundamental role in nuclear astrophysics. This work presents a novel technique to study these reactions with the active target system MUSIC whose segmented anode allows the i nvestigation of a large energy range of the excitation function with a single beam energy. In order to verify the method, we performed a direct measurements of the previously measured reactions $^{17}$O$(alpha,n)^{20}$Ne, $^{23}$Na$(alpha,p)^{26}$Mg, and $^{23}$Na$(alpha,n)^{26}$Al. These reactions were investigated in inverse kinematics using $^{4}$He gas in the detector to study the excitation function in the range of about 2 to 6 MeV in the center of mass. We found good agreement between the cross sections of the $^{17}$O$(alpha,n)^{20}$Ne reaction measured in this work and previous measurements. Furthermore we have successfully performed a simultaneous measurement of the $^{23}$Na$(alpha,p)^{26}$Mg and $^{23}$Na$(alpha,n)^{26}$Al reactions.
168 - Z. Papp , S. Moszkowski 2008
Two body data alone cannot determine the potential uniquely, one needs three-body data as well. A method is presented here which simultaneously fits local or nonlocal potentials to two-body and three-body observables. The interaction of composite par ticles, due to the Pauli effect and the indistinguishability of the constituent particles, is genuinely nonlocal. As an example, we use a Pauli-correct nonlocal fish-bone type optical model for the $alpha-alpha$ potential and derive the fitting parameters such that it reproduces the two-$alpha$ and three-$alpha$ experimental data.
126 - Gy. Gyurky , Zs. Fulop , Z. Halasz 2014
In the model calculations of heavy element nucleosynthesis processes the nuclear reaction rates are taken from statistical model calculations which utilize various nuclear input parameters. It is found that in the case of reactions involving alpha pa rticles the calculations bear a high uncertainty owing to the largely unknown low energy alpha-nucleus optical potential. Experiments are typically restricted to higher energies and therefore no direct astrophysical consequences can be drawn. In the present work a (p,alpha) reaction is used for the first time to study the alpha-nucleus optical potential. The measured 64Zn(p,alpha)61Cu cross section is uniquely sensitive to the alpha-nucleus potential and the measurement covers the whole astrophysically relevant energy range. By the comparison to model calculations, direct evidence is provided for the incorrectness of global optical potentials used in astrophysical models.
We study elastic N$alpha $ scattering and produce a quantitative correlation between the range of the effective potential and the energy of the system. This allows the identification of the waves and energies for which the scattering may be said to b e peripheral. We then show that the corresponding phase shifts are sensitive to the tail of the NN potential, which is due to the exchange of two pions. However, the present uncertainties in the experimental phase shifts prevent the use of N$alpha $ scattering to discriminate the existing models for the NN interaction.
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