Study of Radiative Decays Ds1（2536） → Ds（1968） ＋γ and Ds1（2536）→ Ds^＊（2112） ＋ γ in CQM Model

There are some uncertain charazteristics of the Ds1（2536）, which deserves further discussion. Based on the assumption that the meson is constituted by c s, and belongs to T doublet （1^＋, 2^＋）, radiative decays Ds1（2536） → Ds（1968） ＋γ and Ds1（2536） → Ds^＊（2112） ＋ γ are studied in the CQM model The large branching ratios of them from our calculations not only indicate the process may be detected in the future experiments, but also can give a deep comprehension of the structure of it.     

Uncertainty Study of Bd（Bs）→γvv Decays

B^0（Bs）→γvv decays are useful to determining the decay constants fB（fBs） and B（Bs） meson wave function. Using the B meson wave function determined in hadronic B（Bs） decays, we study the uncertainties due to the types of B meson wave functions. We find that the branching ratios are sensitive to the type of wave functions and input parameters, but the energy spectrum is independent. The predicted branching ratios are （0.45-1.04）×10^-9 and （2.14-3.27）×10^-8 for B^0 and Bs decay, respectively.     

Ds→φπ的理论分析

在重夸克极限下,用QCD因子化方法分析Ds→φπ的衰变. 讨论了硬旁观者散射等非因子化贡献,并给出了数值结果,理论预言的分支比与实验相符. 最后,结合D0→K*π的测量值,采用纯惟象的方法估计Ds→φπ的分支比.     

QCD corrections to b→sγγ and exclusive Bs→γγ decay

The short distance QCD corrections to b→sγγ are calculated in the leading logarithmic approximation. The equivalence of operator basis reduction for S-matrix elements by using the equations of motion or by proving a low energy theorem is discussed. We apply the above results to the exclusive B_s→γγ decay. The branching ratio of this decay is found to be 5×10⁻⁷ in the Standard Model. We also found that QCD corrections modify considerably the ratio between CP-even and CP-odd two-photon amplitudes.     

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.     

Is Ds（2700） a charmed tetraquark state？

In this article, we assume that the Ds(2700) is a tetraquark state, which consists of a scalar diquark and a vector antidiquark, and calculate its mass with the QCD sum rules. The numerical result indicates that the mass of the vector charmed tetraquark state is about MV = (3.75±0.18) GeV or MV = (3.71±0.15) GeV from different sum rules, which is about 1 GeV larger than the experimental data. Such tetraquark component should be very small in the Ds(2700).     

Study of Radiative Decays Ds1(2536) → Ds(1968)+γ andDs1(2536) → Ds*(2112)+γ in CQM Model

There are some uncertain characteristics of the D_s1(2536), which deserves further discussion. Based on the assumption that the meson is constituted by c\bar{s}, and belongs to T doublet (1⁺,2⁺), radiative decays D_s1(2536)→D_s(1968)+γ and D_s1(2536)→ D_s*(2112)+γ are studied in the CQM model. The large branching ratios of them from our calculations not only indicate the process may be detected in the future experiments, but also can give a deep comprehension of the structure of it.     

YAG晶体中Cr~（3＋）→Tm~（3＋），Er~（3＋）→Tm~（3＋）的能量

研究了加入敏化离子Ｃｒ３＋和Ｅｒ３＋的Ｔｍ：ＹＡＧ晶体的吸收谱和荧光谱，计算了Ｃｒ３＋、Ｅｒ３＋、Ｔｍ３＋离子的２Ｅ、４Ｉ１３／２、３Ｆ４能态的平均寿命及能量；转移效率、转移速率．得出Ｃｒ３＋→Ｔｍ３＋转移效率为８０％，转移速率为２．１×１０３ｓ－１．由（Ｅｒ，Ｔｍ）：ＹＡＧ的荧光谱可见存在Ｅｒ３＋→Ｔｍ３＋的有效的能量转移．讨论了Ｃｒ３＋→Ｔｍ３＋和Ｅｒ３＋→Ｔｍ３＋能量转移的不同．     

Bs →φπ^0 Decay in the Extra Down-Type Quark Model

Using the QCD factorization approach, we investigate the electro-weak penguin dominated process 13~ --, q57r~ in the extra down-type quark （EDQS） model. We calculate the effects of new physics （NP） on the branching fraction and direct CP asymmetry of the decay mode. It is found that the branching fraction can be increased by 15~o points or dropped by 13~o points than the standard model （SM） value, and its direct CP asymmetry can be increased by 35% points or dropped by 37% points than the SM one. The effects of NP on the direct CP asymmetry are more obvious than on the branching fraction. If this decay mode could be measured in the upcoming LHCb experiment, these results we obtain will be useful for further studies of the EDQS model.     

Ds（0^±） Meson Spectroscopy in Gaussian Sum Rules

Masses of the Ds（0^±） mesons are investigated from a view-point of ordinary light-heavy system in the framework of the Gaussian sum rules, which are worked out by means of the Laplacian transformation to the usual Borel sum rules. Using the standard input of QCD non-perturbative parameters, the corresponding mass spectra and couplings of the currents to the Ds（0^±） mesons are obtained. Our results are mDs（0-） = 1.968±0.016±0.003 GeV and mDs（0＋） = 2.320 ±0.014 ± 0.003 GeV, which are in good accordance with the experimental data, 1.969 GeV and 2.317 GeV.     

Analysis of the excited bottom and bottom-strange states B1（5721）, B2*（5747）,Bs1（5830）, Bs2*（5840）, BJ（5840） and BJ（5970） of the B meson family

In order to make a further confirmation of the assignments of the excited bottom and bottom-strange mesons B1(5721),B2^*(5747),Bs1(5830)and Bs2^*(5840)and identify possible assignments of BJ(5840)and BJ(5970),we study the strong decay of these states with the 3P0 decay model.Our analysis supports the assignments of B1(5721)and B2*(5747)as the 1P'1 and 1^3P2 states,and Bs1(5830)and Bs2^*(5840)as the strange partners of B1(5721)and B2^*(5747).Besides,we tentatively identify the recently observed BJ(5840)and BJ(5970)as the 2^3S1 and 13D3 states.It is noted that these conclusions need further confirmation by measurements of the decay channels BJ(5840)→Bπand BJ(5970)→Bπ.     

Reanalysis of the （0^＋, 1^＋） States Bs0 and Bs1 with QCD Sum Rules

We calculate the masses and decay constants of the P-wave strange-bottomed mesons Bs0 and Bs1 with the QCD sum rules, and observe that the central values of the masses Bs0 and Bs1 are smaller than the corresponding BK and B^＊K thresholds respectively, the strong decays Bs0→ BK and Bs1→B^＊K are kinematically forbidden. They can decay through the isospin violation processes Bs0→ Bsη → Bsπ^0 and Bs1 → Bs^＊η → Bs^＊π^0 .The bottomed mesons Bs0 and Bs1, just like their charmed cousins Ds0（2317） and Ds1（2460）, may be very narrow.     

B→ Ds^（＊）η（′） Decays in Perturbative QCD

In this paper, we calculate the branching ratios for B^＋→ Ds^＋η, B^＋→ Ds^＋η′, B^＋→ Ds^（→）η and B^＋ → Ds^＋η′ decays by employing the perturbative QCD （pQCD） factorization approach. Under the two kinds of η - η′ mixing schemes, the quark-flavor mixing scheme and the singlet-octet mixing scheme, we find that the calculated branching ratios agree well with the currently available experimental upper limits. We also consider the so called ＂fDs puzzle＂, by using two groups of parameters about the Ds^（→） meson decay constants, that are fDs = 241 MeV, fDs^→ = 272 MeV and fDs = 274 MeV, fDs^→ = 312 MeV, to calculate the branching ratios for the considered decays. We find that the results change 30%by using these two different kinds of paramters.     

New physical effects on the decay Bs →γγ in the technicolor model

In this paper we calculate the contributions to the branching ratio of Bs →γγ from charged pseudo-Goldstone bosons appearing in the one generation Technicolor model. We find that the theoretical value of the branching ratio, BR（Bs →γγ）, including the contributions of PGBs, P^± and P8^±, is very different from the standard model （SM） prediction. The new physical effects can provide a one to two order of magnitude enhancement of the SM results. It is shown that the decay Bs →γγ can test new physical signals from the technicolor model.     

B → Ds(*) η (') Decays in Perturbative QCD

In this paper, we calculate the branching ratios for B⁺ → D_s⁺η, B⁺ → D_s⁺η ', B⁺ → D_s^*+η, and B⁺ → D_s^*+η ' decays by employing the perturbative QCD (pQCD) factorization approach. Under the two kinds of η-η' mixingschemes, the quark-flavor mixing scheme and the singlet-octet mixingscheme, we find that the calculated branching ratios agree well withthe currently available experimental upper limits. We also consider the so called ``f_{D_s} puzzle', by using two groups of parameters about the D^(*)_s meson decay constants, that are f_{D_s}=241 MeV, f_{D^*_s}=272 MeV and f_{^D_s=}274 MeV, f_{D^*_s}=312 MeV, to calculate the branching ratios for theconsidered decays. We find that the results change 30% by usingthese two different kinds of paramters.     

New physical effects on the decay Bs→γγ in the technicolor model

In this paper we calculate the contributions to the branching ratio of Bs→γγ from charged pseudo-Goldstone bosons appearing in the one generation Technicolor model. We find that the theoretical value of the branching ratio, BR(Bs→γγ), including the contributions of PGBs, P± and P±8, is very different from the standard model (SM) prediction. The new physical effects can provide a one to two order of magnitude enhancement of the SM results. It is shown that the decay Bs→γγ can test new physical signals from the technicolor model.     

过程e~＋e~－→J／ψ→V＋X（J~（PC）），X→3P的矩分析

用推广的矩分析方法对过程ｅ＋ｅ－→Ｊ／ψ→Ｖ＋Ｘ（ＪＰＣ），Ｘ（ＪＰＣ）→３Ｐ进行了研究，着重讨论了多态耦合的共振峰复杂结构，并由此得到了一些矩的关系式．利用这些关系式，可以通过对实验数据的分析来确定宽共振峰的耦合模式，进而确定它们的质量，宽度，自旋等重要性质。     

QCD因子化方法下两体非轻无粲Bs→VV衰变

利用QCD因子化方法,在标准模型下对Bs?介子衰变到两个轻矢量介子的过程进行了分析.结果表明:(i)在该方法下,非因子化修正对不同的螺旋度振幅的贡献是不同的,有效系数ahi是与末态矢量介子的螺旋度h相关的;(ii)Bs→VV过程中的某些衰变道的分支比是很大的,甚至达到了10^-5的量级,在未来的B物理实验上是完全有可能测量到的;(iii)对大多数衰变道来讲,横向衰变宽度与总宽度的比值Γ^T/Γ是非常小的.这意味着在两体非轻Bs→VV衰变中,末态两个轻矢量介子都趋向于具有零螺旋度.