Ds1（2536）^＋ decays and the structure of P-wave charmed strange mesons

We calculate the D s 1 （2536） ^＋ decays into D＊K channels,including the decay D s 1 （2536） ＋ → D ＋ π-K ＋ through a virtual D＊0 in a constituent quark model.Widths and S/D amplitudes ratio are in agreement with the recent Belle and BABAR data,being the results sensitive to 1 P 1 and 3 P 1 mixture.     

Study of semileptonic decays B_s →D_(s1)(2536)l and B_s →D_(s2)(2573)l in the CQM model

Based on the assumption that Ds1(2536) and Ds2(2573) belong to T doublet (1 ,2 ), we calculate the semileptonic decays of Bs to Ds1(2536) and Ds2(2573) in terms of the Constituent Quark Meson (CQM) model. For Bs → Ds1(2536) l, and Bs → Ds2(2573) l, the order of magnitude of the obtained branching ratios is 10-3. Our numerical results of the semileptonic decays of Bs to Ds1(2536) and Ds2(2573) are large, which implies that two semileptonic decays should be seen in future experiments.     

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.     

Helicity Amplitude Analysis of e^＋e^- ψ（2S） → γχcJ→γ∧∧^-→γpπ^-p^-π^＋＊

An analysis of the helicity amplitude is performed on the process e^＋e^- ψ（2S） → γχcJ→γ∧∧^-→γpπ^-p^-π^＋. The joint angular distributions for each decay chain are given, and we focus on discussing the E1 contributions to ψ（2S） radiative decays, and the violation of the helicity selection rule in χcJ decays into hyperon pairs, together with the possibility of observing parity violation in successive hyperon decays.     

New Physics Effects on Rare Decays Bu^＋ → π^＋e^＋e^-, ρ^＋e^＋e^- in a Top Quark Two-Higgs-Doublet Model

Using the form factors from light-cone sum rules, we study the branching ratios and forward-backward asymmetries （FBAs） of the exclusive decays Bu^＋→π^＋e^＋e^- and Bu^＋ →ρ^＋e^＋e^- （e= e,μ） in the standard model （SM） and the top quark two-Higgs-doublet model （T2HDM）. From the numerical results, we find that the new physics contributions cannot provide very large enhancement to the branching ratios and the theoretical predictions are in good agreement with the SM ones. The T2HDM effects on FBAs of these decays are small. Precision measurements of the dilepton invariant mass distributions, especially in the lower dilepton mass region, and the FBAs in the decays Bu^＋ → π^＋ （ρ^＋ ）e^＋ e^- will greatly help in discriminating among the SM and the new physics models.     

Radiative Decays of （0^＋, 1^＋） Strange-Bottom Mesons

In this article, we assume that the （0^＋,1^＋） strange-bottom mesons are the conventional bs mesons, and calculate the electromagnetic coupling constants d, g1, g2, and g3 using the light-cone QGD sum rules. Then we study the radiative decays Bs0→Bs^＊γ, Bs1→Bsγ, Bs1→Bs^＊γ, and Bs1→Bs0γ, and observe that the widths are rather narrow. We can search for the （0^＋, 1^＋） strange-bottom mesons in the invariant Bsπ^0 and Bs^＊π^0 mass distributions in the strong decays or in the invariant Bs^＊γ, and Bsγ mass distributions in the radiative decays.     

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.     

News on PHOTOS Monte Carlo： γ＊→π^＋π^-（γ） and K^±→π^＋π^-e^±υ（γ）

PHOTOS Monte Carlo is widely used for simulating QED effects in decay of intermediate particles and resonances. It can be easily connected to other main process generators. In this paper we consider decaying processes γ＊→π^＋π^-（γ） and K^±→π^＋π^-e^±υ（γ） in the framework of Scalar QED. These two processes are interesting not only for the technical aspect of PHOTOS Monte Carlo, but also for precision measurement of αED（Mz）, g--2, as well as ππ scattering lengths.     

Combined fit to BABAR and Belle Data on e^＋e^- →φπ^＋π^- and φf0（980）

A combined fit is performed to the BABAR and Belle measurements of the e^＋e^- →φπ^＋π^- and φf0（980） cross sections for center-of-mass energy between threshold and 3.0 GeV. The resonance parameters of the φ（1680） and Y（2175） are determined. The mass is （1681-12^＋10） MeV/c^2 and the width is （221-24^＋34） MeV/c^2 for the φ（1680）, and the mass is （2117-49^＋59） MeV/c^2 and the width is （164-80^＋69） MeV/c^2 for the Y（2175）. This information will shed light on the understanding of the nature of the excited φ and Y states observed in e＋e- annihilation.     

Thermal Rate Constants of the N（^4S）＋O2（X^3∑g^-） → NO（X^2Ⅱ） ＋O（^3P） Reaction on the ^2A′ Potential Energy Surface

A quasiclassical trajectory study with the sixth-order explicit symplectic algorithm for the N（^4S）＋O2（X^3∑g^-） → NO（X^2Ⅱ） ＋O（^3P） reaction has been reported by employing a new ground potential energy surface. We have discussed the influence of the relative translational energy, the vibrational and rotational levels of O2 molecules on the total reaction cross section. Thermal rate constants at temperatures 300, 600, and 1000 K determined in this work for the reaction are 4.4 × 10^7, 1.8 × 10^10, and 3.1 × 10^11 cm^3mol^-1s^-1, respectively. It is found that they are in better agreement with the experimental data than previous theoretical values.     

Determination of Astrophysical 13N（p,γ）^14O S-factors from the Asymptotic Normalization Coefficient of ^14C→^13C ＋ n

The angular distribution of the ^13C（d,p）^14C reaction is reanalysed using the Johnson-Soper approach. The squared asymptotic normalization coefficient （ANC） of virtual decay ^14 C →^13 C^14＋ n is then derived to be 21.4±5.0 fm^-1. The squared ANC and spectroscopic factor （SF） of ^14O→^13N ＋p are extracted to be 30.4± 7.1 fm^-1 and 1.94 ± 0.45, respectively. The astrophysical S-factors and reaction rates of ^13N（p, γ）140 are determined from the ANC of ^14O → ^13N ＋ P using the R-matrix approach.     

Quasi-classical trajectory investigation on the stereodynamics of Li ＋ DF（v=1-6,j=0）→LiF＋D reaction

In this paper, the stereodynamics of Li ＋ DF → Li F ＋ D reaction is investigated by the quasi-classical trajectory（QCT）method on the ^2A＇ potential energy surface（PES） at a relatively low collision energy of 8.76 kcal/mol. The scalar properties of the title reaction such as reaction probability and cross section are studied with vibrational quantum number of v = 1–6. The product angular distributions P（θr） and P（φr） are presented in the same vibrational level range. Moreover, two polarization-dependent generalized differential cross sections（PDDCSs）, i.e., the PDDCS00 and PDDCS22＋are calculated as well. These stereodynamical results demonstrate sensitive behaviors to the vibrational quantum numbers.     

Lepton-number-violating decays of singly-charged Higgs bosons in the type-（Ⅰ＋Ⅱ ） seesaw model

The lepton-number-violating decays of singly-charged Higgs bosons H^± are investigated in the minimal type-（ Ⅰ＋Ⅱ ） seesaw model with one SU（2）L Higgs triplet △ and one heavy Majorana neutrino N1 at the TeV scale. We find that the branching ratios B（H^＋ → 1α^＋υ^-） （for α = e,μ,τ） depend not only on the mass and mixing parameters of three light neutrinos υi （for i = 1, 2, 3） but also on those of N1. Assuming that the mass of N1 lies in the range of 200 GeV to 1 TeV, we figure out the generous interference bands for the contributions of υi and N1 to B（H^＋→ 1α^＋υ^-）. We illustrate some salient features of such interference effects by considering three typical mass patterns of υi, and show that the relevant Majorana CP-violating phases can affect the magnitudes of B（H^＋→ 1α^＋υ^-）） in this parameter region.     

Study of ππ final state interactions in ψ（2S） →π^＋π^-J/ψ

The π^＋π^ transition of heavy quarkonia in decay ψ（2S） →π^＋π^-J/ψ is studied. With the BESII data on the decay ψ（2S） →π^＋π^-J/ψ, we update the values of coupling constants （gi） and chromopolarizability （αψ（2s）J/ψ） in this process.     

B→K0^＊（1430）K Decays in Perturbative QCD Approach

In this article, we calculate the branching ratios of B→K0^＊ （1430）K decays by employing the pertur-bative QCD （pQCD） approach at leading order. We perform the evaluations in the two scenarios for the scalar meson spectrum. We find that （i） The leading order pQCD predictions for the branching ratio Br（B^＋→K^＋K0^＊（1430）^0）are in good agreement with the experimental upper limit in both scenarios, while the pQCD predictions for other considered B→K0^＊（1430）K decay modes are also presented and will be tested by the LHC experiments; （ii） The annihilation contributions play an important role in these considered decays, for B^0→K0^＊（1430）^±K^± decays,for example,which are found to be （1-4）×10^-6.     

B → ρ（ω, φ）η（＇） Decays and NLO Contributions in pQCD Approach

By employing the perturbative QCD （pQCD） factorization approach, we calculate some important next- to-leading-order （NLO） contributions to the two-body charmless hadronic decays B^＋ →ρ^＋η（＇） and B^0 → ρ^0（ω, φ）η（＇）, induced by the vertex QCD corrections, the quark-loops as well as the chromo-magnetic penguins. From the numerical results and phenomenological analysis we find that （a） for B^± → ρ^±η（＇） （B^0 → ρ^0（ω, φ）η（＇）decays, the partial NLO contributions to branching ratios are small （large） in magnitude; and （b） the pQCD predictions for ACP^dir（B^± → ρ^±η（＇）） are consistent with the data, while the predicted .ACP（B^0 → ρ^0（ω）η（＇）） are generally large in magnitude and could be tested by the forthcoming LHCb experiments.     

Evidence for resonant structures in e＋e-→π＋π-hc

Abstract： The cross sections of e＋e-→π＋π-hc at center-of-mass energies from 3.90 to 4.42 GeV were measured by the BESIII and the CLEO-c experiments. Resonant structures are evident in the e＋e-→π＋π-hc line shape. The fit to the line shape results in a narrow structure at a mass of （4216±18） MeV/c2 and a width of （39±2） MeV, and a possible wide structure of mass （4293±9） MeV/c2 and width （222=k67） MeV. Here, the errors are combined statistical and systematic errors. This may indicate that the Y（4260） state observed in e＋e-→π＋π-J/ψ has a fine structure in it.     

Resonant Reaction in Rb-Cs Vapour Mixture Rb（5P1/2） ＋ Cs（6P3/2） → Cs（8S1/2）＋Rb（5S1/2）

We experimentally study energy-pooling collision in the Rb-Cs vapour mixture at low densities in a cell. Atoms are excited to Rb（5P1/2） and Cs（6P3/2） states using two single-mode diode lasers. To isolate the heteronuclear contribution in the fluorescence spectrum, a double-modulation technique is adopted. The excited-atom density and spatial distribution are mapped by monitoring the absorption of a counterpropagating single-mode diode laser beam, tuned to Rb（5P1/2 → 7S1/2） and Cs（6Pa/2 → 8S1/2） transitions, respectively, which could be translated parallel to the pump beams. The excited atom densities are combined with the measured fluorescence ratios to determine cross section for the energy-pooling process [i.e. Rb（5P1/2） ＋Cs （6P3/2） → Cs（8S1/2）＋Rb （5S1/2）]. The cross section is 3.79 × 10^-14 cm^2 ± 45%.     

Quasi-classical Trajectory Study of Reaction O （^3P）＋HCl （v =2; j=1,6,9） →OH＋Cl

The reaction O（^3P）＋HCl （v=2; j= 1,6,9） → OH＋Cl is theoretically studied with a quasi-classical trajectory method （QCT） on the benchmark potential energy surface of the ground 3A＇＇ state [J. Chem. Phys. 119（2003）9550]. The QCT-calculated state-resolved rotational distributions are in good agreement with the experimental results. The rotational polarization of the product OH molecule becomes weaker as the initial HCl rotation is excited. The calculated results can be explained from the large mass factor cos2 β of the title reaction, the van der Waals well in the potential energy surface and the secondary encounters in the exit channel.     

Determination of J/ψ Event Number via J/ψ → μ^＋μ^- and J/ψ → e^＋e^- at BESⅢ

The decays of J/ψ → μ^＋μ^- and J/ψ → e^＋e^- are studied by Monte-Carlo simulation, based on the Beijing Spectrometer （BES）Ⅲ offtine software system. The methods of determination of the J/ψ event number via J/ψ → μ^＋μ^- and J/ψ → e^＋e^- are presented, respectively. These methods can be used to determine the J/ψ event number for the coming BESⅢ J/ψ data sample.