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.     

钪原子的自电离里德伯能级3d4s(~1D_2)nf~2D_(3/2),3d4s(~1D_2)nf~2F_(5/2)和3d4s(~1D_2)np~2D_(3/2)的理论研究

在多通道量子亏损理论框架下,利用相对论多通道理论,分别在冻结实近似和考虑偶极极化下计算钪原子的Jπ=(3/2)-,(5/2)-的三个收敛于[Ar]3d4s(1D2)的自电离里德伯系列的能级.对3d4s(1D2)np2D3/2和3d4s(1D2)nf2F5/2这两个系列,计算结果表明,考虑偶极极化效应后,理论计算和实验测量的量子数亏损之差普遍小于0.01.而对3d4s(1D2)nf2D3/2系列,考虑偶极极化效应后的结果和仅考虑冻结实的结果比较接近,理论计算和实验测量的量子数亏损之差普遍在0.04左右.     

Study of pure annihilation decays B_(d,s)→D~0~0

Within the heavy quark limit and the hierarchy approximation λQCD mD mB, we analyze the B → D00 and Bs → D00 decays, which occur purely via annihilation type diagrams. As a rough estimate, we calculate their branching ratios and CP asymmetries in the perturbative QCD (PQCD) approach. The branching ratio of B → D00 is about 3.8×10-5 that is just below the latest experimental upper limit. The branching ratio of Bs → D00 is about 6.8×10-4, which could be measured in LHC-b. From the calculation, it is found that this branching ratio is not sensitive to the weak phase angle γ. In these two decay modes, there exist CP asymmetries because of the interference between weak and strong interaction. However, these asymmetries are too small to be measured easily.     

Branching fractions and direct C P asymmetries of ■_s →K~0h~+h′~-(h(′)=K,π) decays

Motivated by the recent LHCb collaboration measurements of charmless three-body decays of ■s meson, we calculate the branching fractions of ■ s →K0π+π-, ■s→K0K+K-, ■s→K0π+K- and ■s→K0K+π- decay modes using the factorization approach.Both the resonant and nonresonant contributions are studied in detail. For the decays ■s→K0π+π- and ■s→K0K+K-, our results agree well with experimental data, and the former is dominated by the K*, while the latter one is dominated by the nonresonant contribution. Considering the flavor S U(3) symmetry violation, the sum of branching fractions of ■s→K0π+K- and ■s→K0K+π-could accommodate the data well too. It should be noted that both branching fractions are sensitive to the scalar density Kπ|ˉsq|0.Furthermore, the resonant contributions are dominated by the scalar K*0(1430). We hope that these branching fractions could be measured individually in the experiments so as to test the factorization approach and the flavor S U(3) asymmetry. Moreover, the direct C P asymmetries of these decays are also investigated, which could be measured in the running LHCb experiment and Super-b factory in the future.     

Mo(d,x)~(95m)Tc,Mo(d,x)~(96g),Tc和Mo(d,x)~(97)Tc反应的激发函数

用活化法和迭靶技术,测量了入射氘核能量从3.2到13.3MeV范围内,Mo(d,x)~(95m)Tc,Mo(d,x)~(96g)Tc和Mo(d,x)~(97m)Tc反应的激发函数,并与复合核统计模型理论计算作了比较。     

Rare decays B_(s,d)~0→e+e~- in a top quark two-Higgs-doublet model

In the framework of T2HDM,we calculated the new physics contributions involving neutral Higgs bosons to the branching ratios of Bs0,d→e+e-(= e,μ) decays.Comparing the theoretical predictions with the experimental upper-limits,we found that(a) The data of Br(B0d →e+e-) give the upper bound on tanβ:tanβ 22,while Br(Bs0 →e+e-) give tanβ 12 for fixed δ = 0°,mH+= 350 GeV,mH0 = 160 GeV,mh0 = 115 GeV and mA0 = 120 GeV;(b) A light neutral Higgs boson mass mh0(mA0) less than 50 GeV(120 GeV) is excluded by the data o...     

Phenomenological studies on B~0 → [K~-π~+]_(S/V)[π~+π~-]_(V/S) → K~-π~+π~+π~- decay

Within the quasi-two-body decay model,we study the localized CP violation and branching fraction of the four-body decay B~0→[K~-π~+]_(s/V)[π~+π~-]_(V/)S→K-π~+π~-π~+ when the K~-π~+and π~-π~+ pair invariant masses are0.35 m(K~-π~+)2.04 GeV and 0 mπ~-π~+1.06 GeV,with the pairs being dominated by the K_0~*(700)~0,K~*(892)~0,K~*(1410)~0,K_0~*(1430) and K~*(1680)~0,and fo(500),ρ~0(770),ω(782) and fo(980) resonances,respectively.When dealing with the dynamical functions of these resonances,fo(500),ρ~0(770),fo(980) and K_0~*(1430) are modeled with the Bugg model,Gounaris-Sakurai function,Flatte formalism and LASS lineshape,respectively,while the others are described by the relativistic Breit-Wigner function.Adopting the end point divergence parameters ρA ∈[0,0.5] andΦ_A∈[0,2π],our predicted results are F_(CP)(B~0→K~-π~+π~+π~-)∈[-0.365,0.447] and B(B~0→K-π~+π~+π~-)∈[6.11,185.32] x 10~(-8),based on the hypothetical qq structures for the scalar mesons in the QCD factorization approach.Meanwhile,we calculate the CP violating asymmetries and branching fractions of the two-body decays B~0→SV(VS) and all the individual four-body decays B~0→SV(VS)→K~-π~+π~-π~+,respectively.Our theoretical results for the two-body decays B~0→K~*(892)~0 fo(980),B~0→K_0~*(1430)~0ω(782),B~0→K~*(892)~0 f~0(980),B~0→K_0~*(1430)~0ρ,and B~0→(1430)~0ω are consistent with the available experimental data,with the remaining predictions await testing in future high precision experiments.     

Ω BARYONS(S=-3,I=0)Ω~-=sss

<正>Ω~-I(J~P)=0(3/2~+)Status:****The unambiguous discovery in both production and decay was by BARNES 64.The quantum numbers follow from the assignment of the particle to the baryon decuplet.DEUTSCHMANN 78 and BAUBILLIER 78 rule out J=1/2 and find consistency with J=3/2.AUBERT.BE 06 finds from the decay angular distributions ofΞ_c~0→Ω~-K~+andΩ_(c~0)→Ω~-K~+that J=3/2;this depends on the spins of theΞ_c~0 andΩ_c~0 being J=1/2,their supposed values.We have omitted some results that have been superseded by later experiments.See our earlier editions.     

∑BARYONS(S=-1,I=1)∑~+=uus,∑~0=uds,∑~-=dds

<正>~~     

Pure annihilation decays of B_s~0→a_0~+a_0~- and B_d~0→K_0~(*+)K_0~(*-) in the PQCD approach

We study the CP-averaged branching fractions and the CP-violating asymmetries in the pure annihilation decays ofB _s~0→a_0~+a _0~-andB _d~0→K_0~(*+)K_0~(*-),where a_0[K_0~*]denotes the scalar a_0(980) and a_0(1450)[K_0~*(800)(ork)and K_0~*(1430)],with the perturbative QCD factorization approach under the assumption of two-quark structure for the a_0and K_0~*states.The numerical results show that the branching ratios of theB _d~0→K_0~(*+)K_0~(*-)decays are in the order of 10~(-6),while the decay rates of theB_s~0→a_0~+a _0~-modes are in the order of 10~(-5).In light of the measured modes with the same quark components in the pseudoscalar sector,namely,B _d~0→K~+K~-and B_s~0→p p~(+-),the predictions for the considered decay modes in this work are expected to be measured at the Large Hadron Collider beauty and/or Belle-Ⅱ experiments in the (near) future.Meanwhile,it is of great interest to find that the twist-3 distribution amplitudes φ~S and φ~T with inclusion of the Gegenbauer polynomials for the scalar a_0(1450) and K_0~*(1430)states in scenario2 contribute slightly to the branching ratios while significantly to the CP violations in the B_d~0→K_0~*(14 30)~+K_0*(14 30)~-and B_s~0→a_0(1450)~+a_0(1450)~-decays,which indicates that,compared to the asymptotic φ~Sand φ~T,these Gegenbauer polynomials could change the strong phases evidently in these pure annihilation decay channels.These predictions await for the future confirmation experimentally,which could further provide useful information to help explore the inner structure of the scalars and shed light on the annihilation decay mechanism.     

△BARYONS(S=0,I=3/2)△~(++)=uuu,△~+=uud,△~0=udd,△~-=ddd

<正>~~     

T_(1u)h_g杨-泰乐系统:D_(5d)势阱中的各向异性现象

杨 泰乐 (Jahn Teller缩写为JT)系统在其最低的绝热势能面上常常典型地含有一系列相互等同的势阱 .在C6 0 分子中 ,若一个电子占据该分子的三重简并的能量最低电子态 ,这一具有T1u 对称性的电子态将会与具有hg 对称性的五重简并振动态发生相互作用 ,形成所谓的T1u hgJT系统 .当考虑电声的非线性相互作用时 ,该系统的势能面上将出现D5d对称性的势阱并伴随D3d对称性的势垒 ;反之亦然 .本文在幺正平移变换的基础上 ,引入了标度变换 ,研究了该JT系统中D5d势阱中的各向异性现象 :在电子空间中 ,非线性项的引入使得阱中的能级分裂 ,通过计算 ,得到了阱中各能级的对称性及其相应的能量表达式 ;在电声耦合强度有限的情况下 ,利用幺正平移和标度变换 ,对阱中的能级分裂、声子的重叠积分以及能级的反演分裂都进行了计算 .其结果不仅展示了各向异性效应对系统中以上各物理量的影响 ,且对C6 0 分子的阴离子态C-6 0 及其相关物质的进一步研究都有着重要的意义     

≡BARYONS(S=-2,I=1/2)≡~0=uss,≡~-=dss

<正>~~     

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   

BOTTOM MESONS(B=±1)B~+=u,B~0=d,B~0=db,B~-=b,similarly for B~*'s

<正>B-particle organization Many measurements of 8 decays involve admixtures of B hadrons.Previously we arbitrarily included such admixtures in the B~±section,but because of their importance we have created two new sections:B~±/B~0 Admixture"for T(4S)results and"B~±/B~0/B_(s~0)/b-baryon Admixture"for results at higher energies.Most inclusive decay branching fractions and x_b at high energy are found in the Admixture sections.B~0-B~0mixing data are found in the 6°section,while B_(s~0)-B_(S~0)mixing data and B-B mixing data for a B~0/B_(s~0)admixture are found in the B_(s~0)section.CP-violation data are found in the B~±,S~0,and B~±B~0 Admixture sections.b-baryons are found near the end of the Baryon section.Recently,we also created a new section:"V_(cb)and     

Long-distance dominance of the CP asymmetry in B→X(s,d)γ decays

We show that in the standard model the parametrically leading (by a factor 1/α(s)) contribution to the inclusive CP asymmetry in B→X(s,d)γ decays arises from a long-distance effect in the interference of the electromagnetic dipole amplitude with the amplitude for an up-quark penguin transition accompanied by soft gluon emission. Using model estimates for the associated hadronic parameter Λ(17)(u), we predict a value in the range -0.6% < A(X(s)γ)(SM) < 2.8%. In view of current experimental data, a future precision measurement of the flavor-averaged CP asymmetry would signal the presence of new physics only if a value below -2% was found. A cleaner probe of new physics is offered by the difference of the CP asymmetries in charged versus neutral B→X(s,d)γ decays.     

Study on the A~2Π_(3/2u), B~2Δ_(3/2u), and X~2Π_(3/2g) states of Cl_2~+ including its isotopologues

Adopting the experimentally available vibrational constants in a recent analysis of the strong perturbation between the A22Π3/2u and BΔ3/2u states of Cl+2in the A–X band system [Gharaibeh et al. 2012 J. Chem. Phys. 137 194317], an unambiguous vibrational assignment of the bands reported previously is carried out. The equilibrium rotational constants Be and α e of the X2Π3/2g and A2Π3/2u states for35Cl+2and35Cl37Cl+and those of the B2Δ3/2u state for35Cl+2are obtained by fitting the experimental values of Bυ. In addition, the values of Be and α e of these three states for the minor isotopologues35Cl37Cl+and37Cl+2are predicted by employing the isotopic effect. The values of equilibrium internuclear distance Re of the three states for the three isotopologues are calculated as well.     

QCD因子化在湮没衰变_(s,d)~0→J/ψγ中的应用

在QCD因子化框架下 ,对可能的辐射湮灭衰变 B0s ,d→J/ψγ进行研究 .在标准模型中 ,相对于简单因子化下领头阶的分支比 ,αs 阶非因子化辐射修正对分支比有显著的量级上的改变 ,这些衰变可用来检验因子化方法 .在理论上 ,B介子稀有辐射衰变对超出标准模型的新物理特别敏感 .作为一个例子 ,我们考虑右手带电流对标准模型中左手流可能的混合效应 ,这个混合对衰变分支比有显著的影响 .     

在N_2中[V_nCr_(3-n)(μ_3-O)(μ-O_2CCH_3)_6(THF)_3]X[n=0-3,X=Cl~-,ClO_4~-,(VO_5)_(0.5)~-]及[V_nFe_(3-n)(μ_3O)(μ-O_2CCH_3)_6(THF)_3]X(n=0-3,X=Cl~-)反应行为的原位红外光谱研究

利用原位红外光谱研究标题化合物在N2 中的反应行为。发现它们在不同温度下能使乙酸分别转化为丙酮和甲烷。它们对乙酸的丙酮化反应活性顺序 :[V3OAT]>[VFe2 OAT],[V2 CrOAT]>[Fe3OAT],[VCr2 OAT]>[Cr3OAT][OAT =(μ3 O) (μ O2 CCH3) 6(THF) 3]。它们对乙酸的甲烷化反应活性顺序 :[Cr3OAT]>[VCr2 OAT],[V2 CrOAT]>[V3OAT]>[VFe2 OAT],[FeO3OAT]。对乙酸的丙酮化反应活性[Fe3OAT]明显低于 [Fe3OAH][OAH =(μ3 O) (μ O2 CCH3) 6(H2 O) 3]。对乙酸的甲烷化反应活性 [Cr3OAT]也明显低于 [CrOAH]。并对上述 [Fe3OAT],[Cr3OAT]与 [Fe3OAH],[Cr3OAH]之间差异进行了讨论。