C12（d,p）C13反应中存在一个中间结构的可能性

在氘核能量为0.5-2.5MeV能区,测量了C¹²（d,d）C¹²,C¹²（d,p₀）C_8.3.¹³,C¹²（d,p₁）C_13t¹³,C¹²（d,p₂）C_2nd¹³和C¹²（d,p₃）C_3rd¹³反应在几个角度上的激发函数,及在一些能量点上的角分布。围绕E_d=1.73MeV附近,在角分布和激发函数中出现有规律变化趋势,讨论了不同反应机制之间相干,并探讨了孤立“门态”存在的可能性。     

23Na（p,α）20Ne反应中几个非孤立共振的研究

本工作测量了²³Na（p,α₀）²⁰Ne_g.s.反应在 E_p=1—2.5MeV 能量范围内和θ_L=30°,150°时的激发函数,还测量了²³Na（p,α₁）²⁰Ne_lst,反应在上述能量范围内和θ_L=30°时的激发函数.对2.171 MeV 共振,在12个角度上测量了（p,α₀）的激发函数,并由激发函数求得了多个角分布,另外在一个固定能量上（150°激发函数的共振峰上）测量了（p,α₀）反应的角分布.对2.117 MeV 共振,在二个固定能量上（150°激发函数的共振峰上和其高能端的半高点处）测量了（p,α₀）反应的角分布.对2.075 MeV 共振,在16个角度上测量了（p,α₀）反应的激发函数,并由激发函数求得了角分布.这三个共振的角分布不是90°对称的,并且共振峰的峰位与角度有关.用复合核理论对它们进行了讨论.     

Be9(d,p),(d,t),(d,a)反应研究

本文在E_d=0.1—2.5MeV能量范围内,研究了Be⁹(d,p₀)Be¹⁰(0),Be⁹(d,p₁)Be¹⁰(3.368MeV),Be⁹(d,t₀)Be⁸(0),Be⁹(d,α₀)Li⁷(0)及Be⁹(d,α₁)Li⁷(0.478MeV)诸反应。在E_d=0.150,0.220,0.401,0.706,1.005,1.301,1.484,1.750,2.000,2.250和2.500MeV共十一个能量上分别测量了这五群出射粒子在θ_L=10—155°区间的角分布。在θ_L=135°,E_d=0.1—2.5MeV,在θ_L=95°,E_d=0.1—2.2MeV,和在θ_L=112.5°,E_d=0.5—2.5MeV测量了Be⁹(d,p₀)Be¹⁰的激发函数。在θ_L=135°和112.5°,E_d=1.2MeV,用较厚靶(100—300μg/cm²)测量了Be⁹(d,p₀)Be¹⁰(0)反应的截面绝对值,结果为σ_(p0)(θ_L=135°)=1.60mb/sr,σ_(p0)(θ_L=112.5°)=1.55mb/sr。这样就得到了在此能区内,这五群出射粒子的截面情况。对所得结果进行了一些讨论。     

Fourth generation effects in Bs→π^-K^＋ decay

We study the effects of the fourth quark generation model in B_s → π^-K⁺ decay. Combining with the up-to-date experimental measurement for B(B_s → π^-K⁺) and A_cp^dir(B_s → π^-K⁺) by the CDF Collaboration, we derive the new bound of weak phase ø_bd, which are 0°< ø_bd <44°, 321°< ø_bd < 360° and 0°< ø_bd < 26°, 342°< ø_bd < 360° for m_t'=400 and 600 GeV respectively. In these regions, B(B_s → π^-K⁺) and A_cp^dir(B_s → π^-K⁺) consist with the current experimental data within errors.     

α粒子在24Mg核上大角反常散射的研究

在?_L=12°至178°,每间隔2°测量了18.1MeVα粒子在²⁴Mg同位素核上的弹性散射角分布和部分非弹性散射角分布。α+²⁴Mg弹性散射角分布在大角区呈现强烈振荡结构,微分截面全面增强。标准光学模型和复合核弹性散射（通过H-F公式）不相干相加的计算不能预言这一反常现象。角动量相关吸收光学模型能相当好地与实验数据拟合。角动量相关吸收势光学模型对其他能量的α粒子在²⁴Mg核上弹性散射实验角分布的拟合也进行了计算和讨论。     

掺铒(Er3+)光纤功率放大器中脉冲非线性放大的理论研究

本文应用稳态和非稳态激光放大理论,分析了两类脉冲信号(t_p》t₂、t_p《t₂)在980nm泵浦的掺Er³⁺光纤功率放大器中的非线性放大特性,讨论了泵浦劝率、信号功率、泵浦能级寿命对脉冲非线性放大的影响.两类脉冲的放大机理不同,其放大特性也大相径庭.     

低密度硅橡胶冲击雨贡纽曲线测量

 采用阻抗匹配法测量了两种低密度（ρ₀＝0.45 g/cm³和ρ₀＝0.47 g/cm³）硅橡胶在2.5~15 GPa压力范围内的冲击雨贡纽参数，p-u_p和u_s-u_p曲线，并采用最小二乘法拟合出C₀，λ′和λ″的值。实验结果与理论预估值符合较好。     

31.2MeV α 粒子在10,11B核上的反应机制的-EFRDWBA分折

利用Mars-Saturn程序对31.2MeV α 粒子在^10,11B核上的反应机制进行了EFR-DWBA的分析.结果表明:对于反应^10,11B(α,t_0,1)^11,12C、¹⁰B(α,t_0,1)¹²C_0,1和¹⁰B(α,p₀)¹³C而言,直接的削裂反应是主要的; 而对于反应¹¹B(α,d₀)¹³C,则是直接的削裂反应的非相干相加; 对于¹¹B(α,p₀)¹⁴C反应,则是上述两种机制相加适合于前、后角区,两中间角区的峰表明复合核反应机制似乎也应考虑进去.     

Study of pure and semileptonic decays of D_s meson within R-parity violating supersymmetric model

We present the comaprative study of semileptonic and leptonic decays of D_s,D^± and D⁰ meson ( D→ M l_α ⁺l_β^-,D→l_α⁺l_β^-,D→l_α⁺v_α ;α,β=e,μ) within the framework of R-parity violating the (R_p) Minimal Supersymmetric Standard Model (MSSM). The comparison shows that combination and product couplings, (λ_βiαλ''_ijq^* or λ''_βqk^*λ''_{α jk}^*) contribution to the branching fractions of the said processes (under consideration) is consistent with or comparable to the experimental measurements in most of the cases. However, some cases exist where these contributions are highly suppressed. We identify such cases in our analysis and single out the important ones suitable for exploring in the future and current experiments.     

代的问题和SO(14)大统一理论

本文提出了三个SO（14）规范群大统一模型。它们能容纳四代通常的费米子。模型A预言了第一代和第二代费米子具有V-A型荷电弱流,而第三代和第四代费米子具有y+A型荷电弱流。在模型B中,我们得到和实验接近的Weinberg值:sin²θ_w=0.225荷电中间玻色子和中性中间玻色子的质量都将比Weinberg-Salam模型中的大1.7倍。模型B预言了另一个质量为100GeV数量级的中性中间玻色子,它与第一、二代费米子的耦合类似于重光子的耦合。模型B的τ—ν_r耦合和模型C的四代轻费米子的荷电弱流都是V—A型。本文中所有的模型都能容纳质量关系:m_α·m_μ～m_d·m_τ,m_μ～3m_s,m_r～m_b,并给出第一Cabibbo角sinθ₁=（（m_d）/（m_s））^1/2。     

(p,π)反应的微观描述

本文推广了W. Weise等人处理π核散射的方法,把它用于研究（p,π）反应,并用此方法计算了³He（P,π⁺）⁴He(T_p^1ab=415MeV)的角分布。所得角分布的形状与实验符合,绝对值比实验值大3-5倍。     

Centrality dependence of pT spectra for identified hadrons in Au+Au and Cu+Cu collisions at √sNN= 200GeV

The centrality dependence of transverse momentum spectra for identified hadrons at midrapidity in Au+Au collisions at √s_NN= 200GeV is systematically studied in a quark combination model. The p_T spectra of π^±, K^±, p(p) and Λ(Λ) in different centrality bins and the nuclear modification factors (R_CP) for these hadrons are calculated. The centrality dependence of the average collective transverse velocity 〈β(r)〉 for the hot and dense quark matter is obtained in Au+Au collisions, and it is applied to a relative smaller Cu+Cu collision system. The centrality dependence of p_T spectra and the R_CP for π⁰, K_s⁰ and Λ in Cu+Cu collisions at √s_NN= 200GeV are well described. The results show that 〈β(r)〉 is only a function of the number of participants N_part and it is independent of the collision system.     

Configuration of the valence neutrons of 17B

The reaction cross section of ¹⁷B on ¹²C target at (43.7±2.4)MeV/u has been measured at the Radioactive Ion Beam Line in Lanzhou (RIBLL). The root-mean-square matter radius (R_rms) was deduced to be (2.92±0.10)fm, while the R_rms of the core and the valence neutron distribution are 2.28fm and 5.98fm respectively. Assuming a ``core plus 2n' structure in ¹⁷B, the mixed configuration of (2s_1/2) and (1d_5/2) of the valence neutrons is studied and the     

16O轰击27Al α粒子发射的研究

用ΔE-E半导体望远镜测量了84.5MeV及62.0MeV ¹⁶O轰击²⁷Al产生的α粒子, 得到了α粒子的发射能谱、角分布、E-θ平面上d²σ/dE﹒dΩ等高图及核温度随发射角的变化. 对产生α粒子的直接机制作了讨论.     

12C（d,d）12C及12C（d,p）13C反应机制的研究

本文用S矩阵理论给出:研究直接过程与复合共振过程相干机制的方法及计算公式;并用它分析了1.63MeVd<2.05MeV能区¹²C（d,d）¹²C、¹²C（d,p₁）¹³C^*及¹²C（d,p₂）¹³C^*反应的机制.结果表明:在此能区内,两种反应机制相干是存在的;并给出了他们之间的定量关系.同时还定出各种直接过程和复合共振过程参数,特别是确定了E_d=1.726,1.767,1.792及1.86MeV 4个共振态的参数.     

Analysis of Bs→φμ+μ- decay within supersymmetry

Motivated by the rst measurement on B(B_s→φμ⁺μ^-) by the CDF Collaboration, we study the supersymmetric e ects in semi-leptonic B_s→φμ⁺μ^- decay. In our evaluations, we analyze the dependences of the dimuon invariant mass spectrum and the forward-backward asymmetry on relevant supersymmetric couplings in the MSSM with and without R-parity. The analyses show that the new experimental upper limits of B(B_s→φμ⁺μ^-)from the LHCb Collaboration could further improve the bounds on sneutrino exchange couplings and (δ_LL^u)₂₃ as well as (δ_LL,RR^u)₂₃ mass insertion couplings. In addition, within the allowed ranges of relevant couplings under the constraints from B(B_s→φμ⁺μ^-), B(B→K^(*)μ⁺μ^-) and (B_s→φμ⁺μ^-), the dimuon forward-backward asymmetry and the di erential dimuon forward-backward asymmetry of B_s→φμ⁺μ^-are highly sensitive to the squark exchange contribution and the (δ_LL^u)₂₃ mass insertion contribution. The results obtained in this work will be very useful in searching for supersymmetric signals at the LHC.     

Analysis of Λb→pK- and pπ- decays in a flavor changing Z' mode

In this paper, we calculate the branching ratios of Λ_b→pK^- and pπ^- decays in the avor changing Z' model. We nd that the branching ratios for these two decay modes are sensitive to the contributions of the Z' boson. For Λ_b→pK^- decay, if the left-handed couplings are equal to the right-handed couplings, the branching ratio of this decay could match up to the currently experimental data for ξ_s=0.01 and -52°<φ_s^L<132°, or ξ_s=0.004 and 0°<φ_s^L<84°; if only the left-handed couplings are considered, it could match up to the experimental data for ξ_s=0.01 and -10°φ_s^L<138°. And for Λ_b→pK^- decay, if the left-handed and right-handed couplings are equal, the branching ratio of Λ_b→pK^- decay may be consistent with the currently experimental data with ξ_d=0.05 and -135°φ_d^L<43°, if only the left-handed couplings are considered, it may be consistent with ξ_d=0.05 and -114°φ_d^L<8°.     

核电荷半径的壳(形变)效应

实验证据分析表明: 大变形区的核电荷方均根半径常数r_p无例外地比相邻球形核大一些. 这可以用形变效应来说明. 中子数在下列壳层中1p_3/2(N~3—6), 1d_5/2(N~9—14), 1f_7/2(N~20—28), 1g_9/2(N~40—50), 1h_11/2(N~70—82)的各同位素的电荷半径的变化(随A的增大半径反而变小等)与A^1/3律完全抵触. 在Z^1/3律基础上, 考虑形变效应后可给予较好的说明.     

一种可能的新型反应机制——双α直接转移反应

假定8Be是由两个在组态空间相邻的α粒子组成的, 因而获得在余核中⁸Be集团的谱密度正比于核表面α粒子预形成几率P_α的平方. 利用改进了的EFRDWBA重叠积分的参数化方法^[1—2], 我们计算了²⁰⁹Bi(¹²C, α)²¹⁷Fr反应中出射的α粒子的角分布和双微分能谱, 而且通过拟合实验数据提取了在²¹⁷Fr核表面的α粒子的预形成几率, 结果与由α衰变数据提取的预形成几率在计算误差范围内一致. 这个事实说明, ²⁰⁹Bi(¹²C, α)²¹⁷Fr可能是双α直接转移反应.     

Pure annihilation type decays B0→Ds- K2+ and Bs→Da2 in perturbative QCD approach

We calculate the branching ratios of pure annihilation type decays B⁰→D_s^- K₂^*+ and B_s→Da₂ using the perturbative QCD approach based on k_T factorization. The branching ratios are predicted to be (60.6_{-16.5-10.4-2.1}^{+17.3+4.3+3.2} )× 10^-6 for B⁰→D_s^- K₂^*+, (1.1_-0.4-0.2-0.1^+0.4+0.1+0.1)×10^-6 for B_s→D⁰a₂⁰ and (2.3_-0.8-0.4-0.1^+0.8+0.2+0.1)×10^-6 for B_s→D^-a₂⁺. They are large enough to be measured in the ongoing experiment. Due to the shortage of contributions from penguin operators, there are no direct CP asymmetries for these decays in the Standard Model. We also derive simple relations among these decay channels to reduce theoretical uncertainties for the experiments to test the accuracy of theory and search of new physics signal.