Applications of the modified Faddeev equations: t + dμ-

We present calculations of the cross-sections for elastic as well as for muon transfer in t + dμ^- collisions below the tμ^-(n = 2) threshold. The appropriate mass-scaled Jacobi coordinates are used in the direct and rearrangement channels. The K-matrix elements are obtained from the solution of multichannel Faddeev equations in the configuration space formulation. A bipolar expansion and spline representation are used in the numerical solution of the modified Faddeev equations. This revised version was published online in August 2006 with corrections to the Cover Date.     

B_(s,d)→μ~+μ_- decays in a flavor changing Z′ model

We study the pure leptonic decays Bs,d →μ+μ- in a Flavor Changing Z′ Model.From the recent measurements of the branching ratios B(Bs,d →μ+μ-),we have derived the bounds on the effective μ-μ-Z′ lepton coupling BμLμ.We find that,(i) if neglecting the contribution from the right-handed lepton coupling BμRμ,we obtain 1.32 < BμLμ < 3.32;(ii) if considering the contribution from the right-handed lepton coupling BμRμ and setting BμLμ =BμRμ,we obtain 0.99相似文献   

Isotope dependence of particle-decay rates of muonic molecular ions (d3,4Heμ) J=1 below (dμ)1s-3,4He threshold

Rates of particle-emitting decay of the resonant state of the muonic molecular ion (dHe) _J=1 lying below the (d)_1s-He threshold can decay to the d-He scattering state. The resonant state is estimated by scattering calculations with the non-adiabatic coupled-rearrangement-channel method. Strong isotope dependence of the decay rates of (d³He) _J=1 and (d⁴He) _J=1 is predicted, though the calculated radiative decay rates of the states are almost the same. In (d³He) _J=1, the particle decay width is three times larger than the radiative decay width, while the two types of decay widths are almost the same in (d⁴He) _J=1. This results in a strong hindrance of the branching ratio of the radiative decay of (d³He) _J=1 compared with the case of (d⁴He) _J=1. This is consistent with a recent observation of the radiative decay of the two molecular states.     

在辐射俘获过程中(dμ)原子的生成截面

在梯形近似下,导出了(dμ)原子的Bethe-Salpeter方程. 在弱耦合条件下求得了l=0的近似BS波函数. 利用这些波函数计算了(dμ)原子在辐射俘获过程中的生成截面.     

dμz／dt=0在电子自旋共振中的物理含义

具有净自旋磁矩物质中的电子在ｚ轴方向外磁 场的作用下，ｄμｚ／ｄｔ＝０从而导致μｚ＝Ｃ，Ｃ为正、负 常数和零，本文对此进行了理论分析和讨论．结果表明：Ｃ 取值的不同，标志着在ｚ轴所加的磁场不同，但只要满足 在垂直于ｚ轴方向上射频场（微波场）的旋转方向和频 率与自旋磁矩μ的拉莫尔进动的方向和频率相同的条 件，都可发生电子自旋共振．并给出了μｚ取不同常数 时μ绕磁场的拉莫尔进动轨迹．     

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.     

Bs,d → μ^μ^- decays in a flavor changing Z＇ model

We study the pure leptonic decays Bs,d → μ^μ^- in a Flavor Changing ZI Model. From the recent measurements of the branching ratios B（Bs,d → μ^μ^-）, we have derived the bounds on the effective μ-μ-Z＇ lepton coupling Bμμ^L. We find that, （i） if neglecting the contribution from the right-handed lepton coupling R L Bμμ^R, we obtain 1.32 〈 Bμμ^L 〈 3.32; （ii） if considering the contribution from the right-handed lepton coupling Bμμ^R and setting Bμμ^R and setting Bμμ^L= Bμμ^R, we obtain 0.99 〈 Bμμ^L 〈 2.19. Our results could be useful for researching Z＇ effects.     

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。     

Energy spectra and energy correlations in the decayH→ZZ→μ+μ−μ+μ−

It is shown that in the sequential decay $H \to ZZ \to (f_1 \bar f_1 ) + (f_2 \bar f_2 )$ , the energy distribution of the final state particles provides a simple and powerful test of theHZZ vertex. For a standard Higgs boson, the energy spectrum of any final fermion, in the rest frame ofH, is predicted to be dΓ/dx～1+β⁴?2(x?1)², with $\beta = \sqrt {1 - 4m_Z^2 /m_H^2 } $ and 1?β≤x=4E/m _H ≤1+β. By contrast, the spectrum for a pseudoscalar Higgs is dΓ/dx～β²+(x?1)². There are characteristic energy correlations betweenf ₁ andf ₂ and betweenf ₁ andf ₂. These considerations are applied to the “gold-plated” reactionH→ZZ→μ⁺μ^?μ⁺μ^?, including possible effects ofCP-violation in theHZZ coupling. Our formalism also yields the energy spectra and correlations of leptons in the decay $H \to W^ + W^ - \to l^ + v_l l^ - \bar v_l $ .     

μ原子和μ子催化的核聚变反应

实现可控核聚变反应,大致有两种方法:一种是所谓热核反应,即把由重氢所组成的等离子体或混合介质加热到足够高的温度例如一亿度,用以克服库仑位垒.磁约束的托卡马克装置,惯性约束的核聚变炉属于这一种;另一种是所谓冷核反应(亦称低温核聚合反应),是以μ子在氖和氖所组成的混合介质中的原子分子过程作为基础的μ子催化法, 一、μ子催化的核聚变连锁过程 μ子是轻子,不参与强相互作用,且其自旋为 1/2,是费米子.它的各种特性与电子很相似,例如带负电的μ-子靠着和原子核的库仑作用形成与氢原子(pe)相类似的介原子(如pμ,dμ,tμ等).但是由于μ…     

μ介子寿命与μ-e对称性的实验限度

μ介子有反常作用,破坏了μ-e对称性。本文讨论了反常作用对弱作用过程的影响,分析了反常作用的电荷无关性和r₅变换性质与μ蜕变弱作用常数的重正化之间的联系,证明了重正化后G_V=G,G_A=εG,ε=1+δ。利用这一结果,可以解释矢量流守恒假定下普适V-A费米弱作用理论在解释μ介子寿命时遇到的困难。从理论和实验的比较中定出δ=0.04,这是由μ蜕变定出的μ-e对称性的实验限度。     

1.30μm／1.55μm SiGe多模干涉滤波器

用多模干涉原理分析和设计了光通信波长（１．３０μｍ～１．５５μｍ）的Ｓｉ１－ｘＧｅｘ／Ｓｉ滤波器，并用模的传播分析方法对其传输特性进行了研究。结果发现，在Ｇｅ含量ｘ＝０．０４时，干涉区的脊高和宽度分别为６．３５μｍ和８μｍ。如果多模干涉区长度ＬＭ＝２３０２．５μｍ，可滤１．３０μｍ而通１．５５μｍ的波长。且具有３１ｄＢ的对比度和０．０１ｄＢ的插入损耗；如果多模干涉区长度ＬＭ＝２５１２．５μｍ，可滤１．５５μｍ而通１．３０μｍ的波长。具有１６ｄＢ的对比度和０．０９ｄＢ的插入损耗。     

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     

Effects of a Family Non-universal Z' Boson in B_d → μ~+μ~-and B~-→ π~-μ~+μ~-,ρ~-μ~+μ~-Decays

Motivated by the recently updated experimental measurement on Bˉd →μ+μ and B →πμ+μ decays by CDF and Belle collaborations,we revisit these decays,as well as B →ρμ+μ decay,within the Standard Model,and evaluate the effects of a family non-universal Z' boson.Under the constraint from B(B →πμ+μ),we find the ranges of the Z' couplings SμLμR 5.2 × 10 2 or DμLμR 8.1 × 10 2 are excluded.Within the allowed Z' parameters spaces,comparing with the SM predictions,we find that B(Bˉd →μ+μ),B(B →πμ+μ),and B(B →ρμ+μ) could be enhanced by a factor about 226%,245%,and 254%,respectively,by Z' contributions.However,they are hardly to be reduced.Furthermore,the zero crossing in the normalized forward-backward asymmetry spectrum of B →ρμ+μ decay at low dimuon mass always exists.     

Insights on d μ t sticking from d μ d stripping and μ,3He capture

Data from the recent PSI high statistics experiment on d μ d fusion are used to measure the stripping process in d μ d→ n+μ,³He and test current calculations of the stripping process. The PSI results in μ³He capture are also used to remove a troubling background from this measurement. Combination of these results with the old dμ t sticking analysis slightly raise and improve that result to ω_s= (0.58± 0.04)% and indicate that theory and experiment can meet if theoretical stripping is increased only at the beginning of the track. This conclusion is in accord with the new stripping calculations where excited state stripping is increased significantly. This revised version was published online in August 2006 with corrections to the Cover Date.     

Be~9(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Be~9(d,p_0)Be~(10)(0),Be~9(d,p_1)Be~(10)(3.368MeV),Be~9(d,t_0)Be~8(0),Be~9(d,α_0)Li~7(0)及Be~9(d,α_1)Li~7(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Be~9(d,p_0)Be~(10)的激发函数。在θ_L=135°和112.5°,E_d=1.2MeV,用较厚靶(100—300μg/cm~2)测量了Be~9(d,p_0)Be~(10)(0)反应的截面绝对值,结果为σ_p_0(θ_L=135°)=1.60mb/sr,σ_p_0(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。     

1.4μm～1.7μm宽带光放大材料研究

宽带光放大是指在整个硅基光纤最低损耗带1.4μm～1.7μm能够获得有效信号净增益的光放大。研究高效的宽带光放大材料可以大大满足人们提高通信容量和实现光集成的要求。材料体系的研究主要集中在稀土掺杂氧化物薄膜、玻璃材料和有机聚合物材料上。着重从宽带的获得、发光性能的改善和发光机理的探索3个方面介绍了稀土掺杂玻璃和薄膜材料的研究进展。结合已经取得的结果和积累的经验,探讨了提高发光效率的方法,指出纳米结构设计的共掺材料体系可以获得有效的宽带发光。最后展望了本领域的发展前景。     

Microscopic description of the reactions d + d → p + 3H and d + d → n + 3He at low energies

A collective adiabatic approach is used to explore the total and differential cross sections for the reactions d + d → p + ³H and d + d → n + ³He at incident-deuteron energies of up to 6 MeV. All substantially contributing partial waves of order not higher than that of G waves are taken into account. The experimental value of the difference of the cross sections for the above mirror reactions is reproduced theoretically under the assumption that nuclear forces obey the condition of isotopic invariance. The positions and amplitudes of the maxima in the calculated total cross sections virtually coincide with those of the corresponding experimental values. It is shown that, around the maxima of the cross sections under study, dominant contributions to them come from the P wave. The sensitivity of observables to the parameters of nucleon-nucleon interaction is analyzed.     

Bs,d → μ+μ- decays in a flavor changing Z' model decays in a flavor changing Z' model

We study the pure leptonic decays Bs,d→μ+μ- in a Flavor Changing Z' Model. Prom the recent measurements of the branching ratios β(Bs,d →μ+μ-).we have derived the bounds on the effective μ-μ-Z' lepton coupling BμμL. We find that, (i) if neglecting the contribution from the right-handed lepton coupling BμμR, we obtain 1.32 < BμμL < 3.32; (ii) if considering the contribution from the right-handed lepton coupling BμμR and setting BμμL = BμμR, we obtain 0.99 < BμμL < 2.19. Our results could be useful for researching Z' effects.