H. Mardanpour, H. R. Amir-Ahmadi, R. Benard, A. Biegun, M. Eslami-Kalantari, L. Joulaeizadeh, N. Kalantar-Nayestanaki, M. Kiš, St. Kistryn, A. Kozela, H. Kuboki… 展开作者
H. Mardanpour, H. R. Amir-Ahmadi, R. Benard, A. Biegun, M. Eslami-Kalantari, L. Joulaeizadeh, N. Kalantar-Nayestanaki, M. Kiš, St. Kistryn, A. Kozela, H. Kuboki, Y. Maeda, M. Mahjour-Shafiei, J. G. Messchendorp, K. Miki, S. Noji, A. Ramazani-Moghaddam-Arani, H. Sakai, M. Sasano, K. Sekiguchi, E. Stephan, R. Sworst, Y. Takahashi, K. Yako
精确的数据提出的分裂反应,$^2{\rm H}(\vec p,pp)n$,在核力研究的框架内。该实验是在KVI使用190兆电子伏的极化质子束撞击液体氘靶,并利用检测器,BINA。一些矢量分析的权力,并与国家的最先进的Faddeev计算,包括三核子力的影响。观察到与$^2{\rm H}(\vec p,^2$ He $)n$通道对应的运动学构型的数据和理论预测之间存在显著差异。这些结果与$^2{\rm H}(\vec p,d)p$反应进行了比较,以检验目前的三核子力模型的同位旋敏感性。目前的两个和三个核子力的模型是不足以描述一致的极化数据的两个同位旋状态。
英文摘要:
Precision data are presented for the break-up reaction, $^2{\rm H}(\vec p,pp)n$, within the framework of nuclear-force studies. The experiment was carried out at KVI using a polarized-proton beam of 190 MeV impinging on a liquid-deuterium target and by exploiting the detector, BINA. Some of the vector-analyzing powers are presented and compared with state-of-the-art Faddeev calculations including three-nucleon forces effect. Significant discrepancies between the data and theoretical predictions were observed for kinematical configurations which correspond to the $^2{\rm H}(\vec p,^2$He$)n$ channel. These results are compared to the $^2{\rm H}(\vec p,d)p$ reaction to test the isospin sensitivity of the present three-nucleon force models. The current modeling of two and three-nucleon forces is not sufficient to describe consistently polarization data for both isospin states.
Experimental results concerning the dynamical fission of quasiprojectiles in semiperipheral collisions for the system 80 Kr+ 48 Ca at 35 MeV/nucleon are presented. Data have been collected with four blocks of the FAZIA setup in the first physics experiment of the FAZIA Collaboration. The degree of isospin equilibration between the two fission fragments and its dependence on their charge asymmetry is investigated. The data are compared with the results of the AMD model coupled to GEMINI as an afterburner, in order to get hints about the timescale of the process.
Neutron-proton effective mass splitting in neutron-rich matter at normal density from analyzing nucleon-nucleus scattering data within an isospin dependent optical model
Symmetry energy and the isospin dependent equation of state
利用30、40和47 MeV/核子的$^{58}$ Ni + $^{58}$ Ni、$^{58}$ Fe + $^{58}$ Ni和$^{58}$ Fe + $^{58}$ Fe反应的多重碎裂产生的碎片,将等标度参数$α$与基于两种不同的核子-核子有效力Gogny和Gogny-AS相互作用的反对称化分子动力学(AMD)计算结果进行了比较.结果表明,Gogny-AS有效相互作用的选择更符合实验数据,得到$\sim$的对称能为18-20 MeV.观察到的值表明,碎片是在$\sim$ 0.08 fm $^{-3}$的降低密度下形成的。
We have studied the isoscalar giant quadruple resonance (ISGQR) and the isovector giant dipole resonance (IVGDR) in $^{208}$Pb based on an improved isospin-dependent Boltzmann-Uehling-Uhlenbeck transport approach using an improved isospin- and momentum-dependent interaction. With the isoscalar nucleon effective mass and the nucleon-nucleon cross section which reproduces respectively the excitation energy and the width of the ISGQR strength function, the slope parameter of the symmetry energy and the neutron-proton effective mass splitting are constrained respectively within $36<L<62$ MeV and $…
We investigate the isospin transport with 40,48 Ca+ 40,48 Ca reactions at 35 MeV/nucleon, measured with the coupling of the VAMOS high acceptance spectrometer and the INDRA charged particle multidetector. Using the quasi-projectile remnant measured with VAMOS and carefully selected light-charged-particles measured in coincidence with INDRA, a reconstruction method is applied to estimate the excited quasi-projectile (QP) on an event-by-event basis. The isospin diffusion is investigated using the isospin transport ratio with the asymmetry $δ$ = (N -- Z)/A of the projectile as an isospin-sensitiv…
An investigation of the isospin equilibration process in the reactions $^{58,64}$Ni+$^{58,64}$Ni at two bombarding energies in the Fermi regime ($32\,$MeV/nucleon and $52\,$MeV/nucleon) is presented. Data have been acquired during the first experimental campaign of the coupled INDRA-FAZIA apparatus in GANIL. Selecting from peripheral to semi-central collisions, both the neutron content of the quasiprojectile residue and that of the light ejectiles coming from the quasiprojectile evaporation have been used as probes of the dynamical process of isospin diffusion between projectile and target for…
Isospin decomposition of the $γ^{(*)} N \to N^*$ transitions as input for constructing models of neutrino-induced reactions in the nucleon resonance region
The isospin dependence of in-medium nuclear effective interactions is a fundamental issue in nuclear physics and has broad ramifications in astrophysics. Its uncertainties, especially the difference of neutron-proton interactions in the isosinglet and isotriplet channels, affect significantly the density and momentum dependence of the isovector single-nucleon potential and nucleon-nucleon short-range correlation in neutron-rich matter. Consequently, the neutron-proton effective mass splitting and the density dependence of nuclear symmetry energy are still rather uncertain. Heavy-ion reactions …
We provide a systematic study of the isospin composition and neutron-to-proton $\left( \frac{N}{Z} \right)$ ratio dependence of nuclear short-range correlations (SRC) across the nuclear mass table. We use the low-order correlation operator approximation (LCA) to compute the SRC contribution to the single-nucleon momentum distributions for 14 different nuclei from $A=4$ to $A=208$. Ten asymmetric nuclei are included for which the neutrons outnumber the protons by a factor of up to 1.54. The computed momentum distributions are used to extract the pair composition of the SRC. We find that there i…
New experimental data obtained from $γ$-ray tagged one-neutron and one-proton knockout from $^{55}$Co is presented. A candidate for the sought-after $T=1, T_z = 0, J^π = 6^+$ state in $^{54}$Co is proposed based on a comparison to the new data on $^{54}$Fe, the corresponding observables predicted by large-scale-shell-model (LSSM) calculations in the full $fp$-model space employing charge-dependent contributions, and isospin-symmetry arguments. Furthermore, possible isospin-symmetry breaking in the $A=54$, $T=1$ triplet is studied by calculating the experimental $c$ coefficients of the isobaric…