论文标题
$ {}^{208} $ pb的中子皮肤厚度从反应横截面确定的质子散射
Neutron skin thickness of ${}^{208}$Pb determined from reaction cross section for proton scattering
论文作者
论文摘要
反应横截面$σ_r$对于确定中子半径$ r_n $以及物质半径$ r_m $很有用。 $^{12} $ c散射的手性（kyushu）$ g $ -matrix折叠模型，$^{9} $，$^{12} $ c，$^{27} $ al targets在入射能量范围内经过$ 30 \ lsim e _ {\ lsir iS} \ lsir and} \ lsir and i; $σ_r$ in $ 30 \ lsim e _ {\ rm in} \ lsim 100 $ mev和$ 250 \ lsim e _ {\ rm in} \ lsim 400 $ mev。 \ item [aim] 我们确定$ r_n $和中性皮肤厚度$ r _ {\ rm skin} $ $ {}^{}^{208} {\ rm pb} $，通过使用$ p+{}^{208} {\ rm pb} {\ rm pb} {\ rm pb} $ in的高质量$σ_r$数据100 $ MEV。 理论模型是kyushu $ g $ -matrix折叠模型，其密度是用带有角动量投影（AMP）的Gongny-D1S HFB（GHFB）计算的。 \ item [结果] 带有GHFB+AMP密度的Kyushu $ G $ -Matrix折叠模型低估了$σ_{\ rm rm r} $ in $ 30 \ leq e _ {\ rm in} \ leq 100 $ 〜MEV仅为0.97倍。 由于使用GHFB+AMP计算的质子半径$ R_P $与5.444 fm的精确实验数据一致，因此理论结果与$σ_R$的数据的小偏差很小，使我们可以扩展GHFB+AMP中子中子密度，以便重现$σ_R$数据。 在$ e _ {\ rm in} $ = 30---100 meV中，可以通过假设中子半径为$ {}^{208} {\ rm pb} $作为$ r_n $ = $ = $ = $ 5.722 \ pm pm 0.035 $ fm，可以通过假设中子半径为$ {}^{208} {\ rm pb} $来复制实验$σ_R$数据。 \ item [结论] 目前的结果$ r _ {\ rm skin} $ = $ 0.278 \ pm 0.035 $ fm与最近的prex-II结果非常吻合，$ r _ {\ rm skin} $ = $ 0.283 \ pm 0.071 $ fm。
The reaction cross section $σ_R$ is useful to determine the neutron radius $R_n$ as well as the matter radius $R_m$. The chiral (Kyushu) $g$-matrix folding model for $^{12}$C scattering on $^{9}$Be, $^{12}$C, $^{27}$Al targets was tested in the incident energy range of $30 \lsim E_{\rm in} \lsim 400 $ MeV, and it is found that the model reliably reproduces the $σ_R$ in $30 \lsim E_{\rm in} \lsim 100 $ MeV and $250 \lsim E_{\rm in} \lsim 400$ MeV. \item[Aim] We determine $R_n$ and the neutron skin thickness $R_{\rm skin}$ of ${}^{208}{\rm Pb}$ by using high-quality $σ_R$ data for the $p+{}^{208}{\rm Pb}$ scattering in $30 \leq E_{\rm in} \leq 100$ MeV. The theoretical model is the Kyushu $g$-matrix folding model with the densities calculated with Gongny-D1S HFB (GHFB) with the angular momentum projection (AMP). \item[Results] The Kyushu $g$-matrix folding model with the GHFB+AMP densities underestimates $σ_{\rm R}$ in $30 \leq E_{\rm in} \leq 100$~MeV only by a factor of 0.97. Since the proton radius $R_p$ calculated with GHFB+AMP agrees with the precise experimental data of 5.444 fm, the small deviation of the theoretical result from the data on $σ_R$ allows us to scale the GHFB+AMP neutron density so as to reproduce the $σ_R$ data. In $E_{\rm in}$ = 30--100 MeV, the experimental $σ_R$ data can be reproduced by assuming the neutron radius of ${}^{208}{\rm Pb}$ as $R_n$ = $5.722 \pm 0.035$ fm. \item[Conclusion] The present result $R_{\rm skin}$ = $0.278 \pm 0.035$ fm is in good agreement with the recent PREX-II result of $r_{\rm skin}$ = $0.283\pm 0.071$ fm.
