关于介分子离子(αp,μ~-)和(αp,2μ~-)

应用ACQM理论和方法研究介分子离子(αp,μ~-)和(αp,2μ~-).发现(αp,μ~-)的基态(X~2Σ~+)为排斥态;(αp,2μ~-)为束缚态,平衡核间距R_e=0.0078bohr,能量极小值E=-551.78a.u.     

关于介分子离子(αp,μ－)和(αp,2μ－)

应用ACQM理论和方法研究介分子离子(αp,μ^－)和(αp,2μ^－).发现(αp,μ^－)的基态(X²Σ⁺)为排斥态;(αp,2μ^－)为束缚态,平衡核间距R_e=0.0078bohr,能量极小值E=－551.78a.u..     

红外中性滤光法(1.8μ—2.5μ和0.7μ—22.5μ)

在红外跟踪,制导等光电子仪器的研制过程中,红外信号的强弱直接影响着跟踪距离和精度,为了取得可靠数据,必须作相应信号的模拟试验,这就需要采用不同透过率和不同光谱范围的中性滤光片。目前我国用量较大的是1.8μ至2.5μ光谱范围的中性滤光片。可见光到1.8μ的中性滤光片已有资料参考,但从可见光到2.5μ的还没见到报导。下面介绍我们镀制1.8μ至2.5μ和O.7μ至2.5μ中性滤光片的情况。     

ON THE MESONIC MOLECULES (αp,μ－) AND (αp,2μ－)

ACQM is applied to study the μ^－-mesenic molecules (αp,μ^－) and (αp,2μ^－).It is found that the ground state X²Σ⁺ of (αp,2μ^－) is the repulsive one and the ground state X¹Σ⁺ of (αp,2μ^－) is a bound state with the equilibrium proton-proton separation R_e=0.0078bohr and the minimum energy E=－551.78a.u..     

Measurement of the forward-backward asymmetry in the B→K*μ(+)μ(-) decay and first observation of the B(s)0→ϕμ(+)μ(-) decay

We reconstruct the rare decays B(+)→K(+)μ(+0μ(-0, B90)→K*(892)(0)μ(+)μ(-), and B(s)(0)→?(1020)μ(+)μ(-) in a data sample corresponding to 4.4 fb(-1) collected in pp collisions at √[s]=1.96 TeV by the CDF II detector at the Tevatron Collider. Using 121±16 B(+)→K(+)μ(+)μ(-) and 101±12 B(0)→K(*0)μ(+)μ(-) decays we report the branching ratios. In addition, we report the differential branching ratio and the muon forward-backward asymmetry in the B(+) and B(0) decay modes, and the K(*0) longitudinal polarization fraction in the B(0) decay mode with respect to the squared dimuon mass. These are consistent with the predictions, and most recent determinations from other experiments and of comparable accuracy. We also report the first observation of the B(s)(0)→?μ(+)μ(-) decay and measure its branching ratio BR(B(s)(0)→?μ(+)μ(-))=[1.44±0.33±0.46]×10(-6) using 27±6 signal events. This is currently the most rare B(s)(0) decay observed.     

195Pt,15N NMR spectroscopy of aqueous solutions of mixed valent oxonitrocomplexes,Pt(II,IV): K5[(NO2)3PtIV(μ-O)3 Pt 3 II (NO2)6] and K8[(NO2)6Pt 3 II (μ-O)3PtIV(μ-O)3Pt 3 II (NO2)6]

Two aqueous solutions of oxonitrocomplexes comprising di- and tetravalent platinum atoms, K₅[(NO₂)₃Pt^IV(μ-O)₃Pt ₃ ^II (NO₂)₆]· 3H₂O and K₈[(NO₂)₆Pt ₃ ^II (μ-O)₃Pt^IV (μ-O)₃Pt ₃ ^II (NO₂)₆] · 7H₂O, have been studied by¹⁹⁵Pt and¹⁵N NMR technique. Both compounds, enriched with the¹⁵N (95%) isotope, were synthesized by thermal denitrozylation of K₂[Pt(NO₂)₄]. Constants of spin-spin scalar coupling,¹⁹⁵Pt-¹⁵N and¹⁹⁵Pt^II-¹⁹⁵Pt^IV, were obtained for tetra-and heptameric complexes in aqueous solutions through multiplet simulation. The¹⁹⁵Pt and¹⁵N NMR spectra of the same solutions obtained two months after their preparation show signals from the hydrolytic forms of the tetrameric complex as well as the signals from mono- di- and trimeric oxonitrocomplex forms of divalent platinum. All signals of species formed as a result of hydrolysis were identified.     

μ介子转化电子装置超导磁体低温系统(英文)

μ介子转化为电子的试验装置(MECO)将安装在美国布鲁克海文国家实验室的交变磁场梯度同步加速器中。一台4.5K千瓦制冷量的氦制冷设备将为MECO试验中的四个大型的超导螺线管磁体提供冷量,针对MECO中超导磁体的性能特点及要求,主要讨论了该低温系统中每个超导磁体的冷却方法以及相应氦制冷机的流程设计方案。     

~(59)Co(n,p)~(59)Fe,~(59)Co(n,α)~(56)Mn,~(59)Co(n,2n)~(58)Co反应截面的测量

本实验用活化法测量了中子能量在12.8MeV到17.8MeV的~(59)Co(n,p)~(59)Fe,~(59)Co(n,α)~(56)Mn,~(59)Co(n,2n)~(58)Co三个反应道的反应截面值,实验的测量误差在3.3％—6.9％范围内. 本文还计算了反应截面测量误差的协方差矩阵,并将实验测量值与理论计算值进行了比较.另外,还对上述三个反应道的截面进行编评,给出了推荐的激发曲线.     

Investigation of rare semileptonic B_c→(D_(s,d)~((*))μ~+μ~- decays with non-universal Z' effect

We analyze different decay observables of semileptonic decays B_c→(D_(s,d)~((*)))μ~+μ~-,such as the branching ratio,forward-backward asymmetry,polarization fraction,and lepton polarization asymmetry in the non-universal Z'model.We further study the dependence of the branching fraction to the new model parameters and find that the values of different decay parameters increase in the Z' model,which indicates a possible approach for the search of new physics as well as for the unknown phenomena of the charm B meson.     

~(186)W(d,p)~(187)W,~(186)W(d,2n)~(186)Re,~(nat)Fe(p,x)~(56)Co和~(nat)Ti(a,x)~(51)Cr反应激发函数评价

考虑特征γ射线分支比、衰变常数和标准截面等修正,对带电粒子引起的核反应~(186)W(d,p)~(187)W,~(186)W(d,2n)~(186)Re,~(nat)Fe(p,x)~(56)Co和~(nat)Ti(a,x)~(51)Cr的激发函数进行了研究。全面收集了这些反应激发函数的实验测量数据,对这些实验数据进行了分析处理,应用数学方法对分析处理后的实验数据进行了拟合。经过评价,给出了50 Me V以下~(186)W(d,p)~(187)W,~(186)W(d,2n)~(186)Re,~(nat)Fe(p,x)~(56)Co和~(nat)Ti(a,x)~(51)Cr反应激发函数的推荐值。     

BESⅢμ子鉴别器μ,π鉴别的研究

用事件产生软件PYTHIA模拟了τ粲能区正负电子对撞的各反应道,得到各反应道产生末态μ子的截面和动量分布.用模拟软件Geant3对BESⅢ的μ子鉴别器进行了模拟.对动量为0?.5GeV/c以上的μ子和π介子的模拟数据,用BP神经网络方法和Fisher判别方法进行μ,π鉴别.BP神经网络具有非线性的模式识别能力,其μ,π鉴别效果显著优于线性的Fisher方法     

Non-resonant zeugmatography with muons (μSI) and radioactive isotopes

The procedure of zeugmatographic imaging — hitherto implemented only with nuclear magnetic resonance to form the well known MRI technique — is examined with the aim of utilizing it also in combination with non resonant phenomena. It is shown that in principle, one may indeed use zeugmatographic schemes with Perturbed Angular Correlations (PAC) or with muon spin rotations (SR) to obtain image information from material bodies. The preliminary experimentation with zeugmatographic Spin Imaging scheme, (SI), will be described. SomeSI imaging results will be presented and the inherent limitations of the method will be discussed.     

~(55)Mn(α,n)~(58m,g)Co,~(55)Mn(α,2n)~(57)Co和~(55)Mn(α,α′n)~(54)Mn反应的激发函数

用活化法和迭靶技术,在入射α粒子能量从10.4到26.5MeV范围内,测量了~(55)Mn(α,n)~(58m,g)Co、~(55)Mn(α,2n)~(57)Co和~(55)Mn(α,α′n)~(54)Mn反应的截面,并同激子模型理论计算作了比较,结果表明在上述反应中存在平衡前发射反应机制。     

Neutrino masses,leptonic flavor mixing,and muon (g-2) in the seesaw model with the U(1)Lμ-Lτ gauge symmetry

The latest measurements of the anomalous muon magnetic moment aμ ≡ (gμ-2)/2 show a 4.2σ discrep-ancy between the theoretical prediction of the Standard Model an...     

Quantized (1, 0) ⊕ (0, 1) Fields

We find a mapping between antisymmetric tensormatter fields and the Weinberg 2(2j + 1)-componentbispinor fields. Equations which describethe j = 1 antisymmetric tensor field coincide with the Hammer-Tucker equations entirely and withthe Weinberg ones within a subsidiary condition, theKlein-Gordon equation. A new Lagrangian for the Weinbergtheory is proposed which is scalar and Hermitian. It is built on the basis of the concept ofWeinberg doubles. The origin of acontradiction between the classical theory, the Weinbergtheorem B – A = for quantum relativisticfields, and the claimed longitudity of the antisymmetrictensor field [transformed on the (1, 0) (0, 1)Lorentz group representation] after quantization isclarified. Analogs of the j = 1/2 Feynman–Dysonpropagator are presented in the framework of the j = 1 Weinberg theory.It is then shown that under a definite choice of fieldfunctions and initial and boundary conditions themassless j = 1 Weinberg–Tucker–Hammerequations contain all the information that the Maxwell equationsfor the electromagnetic field have. Thus, the formerappear to be of use in describing some physicalprocesses.     

~(100)Mo(n,2n)~(99)Mo,~(96)Mo(n,p)~(96)Nb和~(92)Mo(n,α)~(89m+g)Zr反应截面测量

本文报告了在E_n=13.40—14.79MeV中子能区用活化法以~(27)Al(n,α)~(24)Na截面为中子注量标准测得的~(100)Mo(n,2n)~(99)Mo,~(96)Mo(n,p)~(96)Nb和~(92)Mo(n,α)~(89m+g)Zr的反应截面,中子能量是用铌锆截面比法测定的。文中将实验测量值与理论计算值进行了比较,还对上述三个反应的截面进行了编评,给出了推荐的激发曲线。     

[(μ-CF3CO2)2Ln (μ-CF3HCO2) Al (i-Bu)2·2THF]2(Ln=Nd,Y)配合物的NMR和X-射线衍射研究

对[μ-CF₃CO₂)₂Ln(μ-CF₃HCO₂)Al(i-Bu)₂·THF]₂(Ln=Nd,Y)配合物单晶结构的X-射线分析指出,配合物具有中心对称性,配位中心由两个稀土和两个Al离子组成,稀土由两个THF和6个TFA分子配位形成畸变的三盖三棱柱结构,Al由两个TFAG和两个i-Bu配位形成四面体结构。桥连Al与两个稀土的TFA分子的羧基发生歧化加氢,其碳原子由SP²型转变为SP³型.NMR研究表明,在THF溶液中,该配合物保持了它在单晶中的配位结构,所不同的是两个i-Bu在溶液中有两种异构形成,二者间为慢交换过程。     

Computational prediction of a new class of tri-coordinate cyclic heavier carbene analogues RM(μ-R)2AlR2 (M = Ge,Sn, Pb)

Design of stable heavier carbene analogues M(II) (M = Ge, Sn, Pb) with structural motifs different from the traditional di-coordinate analogues is extremely of interest and challengeable. In this paper, we computationally designed a novel class of tri-coordinate cyclic heavier analogues of carbenes covering a number of substituents, i.e., RM(μ-R)₂AlR₂ (M = Ge, Sn, Pb) 1, in which two sets of inter-molecular donor–acceptor interactions were formed between the di-coordinate carbene MR₂ and the AlR₃ moiety. The M-centre was found to undergo both the nucleophilic and insertion reactions, indicative of the ‘carbene’ character. We also designed c-1 starting from the known di-coordinate cyclic MR₂ and AlR₃ under 16 kinds of substituents [NR′₂, OR′, PR′₂, SR′(R′ = H, Me, iPr, Ph)]; c-1 also has favourable thermodynamic stability. After the only known cyclic tri-coordinate M(II) [M₂,R₄] inter-molecularly formed between two di-coordinate MR₂, the presently designed new tri-coordinate cyclic heavier carbene analogues should expand the higher coordinate M(II) family and await future laboratory synthesis.     

Experimental results on40Ca(μ−,v μγ)40K* and16O(μ−,v μγ)16N**)

Photon spectra from radiative muon capture in doubly closed shell nuclei¹⁶O and⁴⁰Ca have been measured with a pairspectrometer. The⁴⁰Ca data agree with the most recent of the three previous experiments, for¹⁶O no other measurements exist. The comparison with theoretical calculations indicates that a careful treatment of the nuclear response function is required, ifg _P is to be determined from the data.Presented at the symposium Mesons and Light Nuclei, Liblice, Czechoslovakia, June 1981.