Radial excitation states of η and η' in the chiral quark model

A chiral quark model is applied to calculate the spectra of pseudoscalar mesons η and η'. By analyzing the obtained spectra, we find that the mesons η'(2¹S₀), η(4¹S₀), η'(3¹S₀) and η'(4¹S₀) are the possible candidates of η(1760), X(1835), X(2120) and X(2370). The strong decay widths of these pseudoscalars to all the possible two-body decay channels are calculated within the framework of the ³P₀ model. Although the total width of η'(2¹S₀) is compatible with the BES Collaboration's experimental value for η(1760), the partial decay width to ωω is too small, which is not consistent with the BES result. If X(1835) is interpreted as η(4¹S₀), the total decay width is compatible with the experimental data, and the main decay modes will be mπ a₀(980) and m π a₀(1450), which needs to be checked experimentally. The assignment of X(2120) and X(2370) to η'(3¹S₀) and η'(4¹S₀) is disfavored in the present calculation because of the incompatibility of the decay widths.     

Uncertainty study of DS-(D-)→γlν (l=e,μ) decays determined by wave function

Wave function is important for determining decay constants f_DS^- and f_D^-. Using the 5 types of D meson wave functions in the heavy quark limit, we studied the uncertainties of radiative pure-leptonic decays of D_S^-(D^-) mesons. The branching ratios are (1.025390—1.706812) × 10^-5 and (0.953498—1.576725) × 10^-6 for D_S^- and D^- decays, respectively, which are sensitive to the type of wave function.     

Mechanism for Alternating Electric Fields Induced-Effects on Cytosolic Calcium

In this work, from the point of calcium ions in the cytosol, we extend a V_m-[Ca²⁺]_cyt model to explain the changes of action potential V_m of the plasma membrane and the calcium concentration in the cytosol [Ca²⁺]_cyt under an alternating electric field in cells. An alternating external electric field may exert an oscillating force to each of the free electrolytes, existing on both sides of the plasma membrane. The mechanism for the alternating electric field induced-effects on V_m and [Ca²⁺]_cyt is elucidated. The simulation results show a correlation between the changes of [Ca²⁺]_cyt and the alternating electric field. When the numerical ratio between the intensity E₀(mV/m) and the frequency υ (Hz) of the field was about 1-2, the [Ca²⁺]_cyt signal is changed dramatically. The bioactive changes of [Ca²⁺]_{_cyt} appear at low frequency, in the range of 0-100Hz.     

SEVERAL PROBABLE QUESTIONS ON "A STUDY OF A SEMICLASSICAL APPROXIMATIONS FOR HEAVY ION TRANSFER REACTIONS"

The identity G(S,θ,π,0)=(－1)^{λ₁－λ₂}G(S,θ,0,0) is proved thus the transition amplitude's formula ((33), H-B,see[1]) stands good under the nonforward angular scattering conditions. The equation (ε₁-Δε₁-h²k₁²/2m_x⁾=(ε₂-Δε₂- h²k₂²/2m_x⁾ in Ref[1] may be questionable. The transfer amplitude's formula ((48), H-B) may be suitable only in post representation. The choice of different representations probablely influences the calculation results. The two symmetry properties of the transfer amplitude can simplify the numerical calculation.     

Study of ψ(4415) in the QPC model

Some authors consider the ψ(4415) to be the 4S or 5S excited tate of a cc pair. Starting from this assumption, we study he decays of the ψ(4415) to DD, D^*D^*, D_SD_S, D_S^*D_S^*, and get the corresponding branching ratios in terms of the Quark-Pair-Creation (QPC) model. Compared with the experimental data, we find that the results of 4S state agree much better than those of the 5S state. Therefore, it is more reasonable to assume the ψ(4415) to be a 4S state.     

Scintillation properties of YPO4: RE (RE=Ce3+, Pr3+ or Nd3+)

The spectra of RE-doped YPO₄ (RE=Ce³⁺, Pr³⁺ or Nd³⁺) have been measured. The spectroscopic and decay kinetics properties of pure host YPO₄ were also studied at 8 K and 300 K, which indicated the host had taken part in the luminescent processes of activators. Under the excitation over the bandgap of the host, the electron could relax to the activators. Through the comparison of spectra and decay time, Nd³⁺ doped YPO₄ had better scinillation properties than Ce³⁺ or Pr³⁺ inYPO₄.     

Masses of heavy-light mesons in Regge phenomenology

The masses of some orbitally and radially excited heavy-light mesons are calculated in Regge phenomenology. The results are in reasonable agreement with the experimental data and those given in many other theoretical approaches. Based on the calculation, we suggest that the recently observed D(2550), D(2600) and D(2760) can be assigned as the charmed members of the 2¹S₀, 2³S₁ and 1³D₁ multiplets, respectively. D_s1^*(2700)^± may be assigned as the charm-strange member of the 2³S₁ state. The results may be helpful in understanding the nature of current and future experimentally observed heavy-light mesons.     

Semileptonic decays Bc→(ηc,J/Ψ)lv in the perturbative QCD approach

In this paper we study the semileptonic decays of B_c^-→(η_c,J/Ψ)l^-v_l. We first evaluate the B_c→(η_c,J/Ψ) transition form factors F₀(q²), F₊(q²), V(q²) and A_0,1,2(q²) by employing the pQCD factorization approach, and then we calculate the branching ratios for all considered semileptonic decays. Based on the numerical results and the phenomenological analysis, we find that: (a) the pQCD predictions for the values of the B_c→η_c and B_c→J/Ψ transition form factors agree well with those obtained by using other methods; (b) the pQCD predictions for the branching ratios of the considered decays are Br(B_c^-→η_c e^-v_e(μ^-v_μ)=(4.41_-1.09^+1.22)×10^-3, Br(B_c^-→η_cτ^-v_τ) =(1.37_-0.34^+0.37)×10^-3, Br(B_c^-→J/Ψ e^-v_e(μ^-v_μ)) =(10.03_-1.18^+1.33)×10^-3, and Br(B_c^-→J/Ψτ^-v_τ) =(2.92_-0.34^+0.40)×10^-3; and (c) we also define and calculate two ratios of the branching ratios R_ηc and R_J/Ψ, which will be tested by LHCb and the forthcoming Super-B experiments.     

Investigations on the charmless decays of Y(4260)

Apart from the charmful decay channels of Y(4260), the charmless decay channels of Y(4260) also provide us a good platform to study the nature and the decay mechanism of Y(4260). In this paper, we propose to probe the structure of Y(4260) through the charmless decays Y(4260)→VP via intermediate D₁D+c.c. meson loops, where V and P stand for light vector and pseudoscalar mesons, respectively. Under the molecule ansatz of Y(4260), the predicted total branching ratio BR_VP for all Y(4260)→VP processes are about (0.34_-0.23^+0.23)% to (0.75_-0.52^+0.72)% with the cutoff parameter α=2-3. Numerical results show that the intermediate m D₁D+c.c. meson loops may be a possible transition mechanism in the Y(4260)→VP decays. These predicted branching ratios are the same order to that of Y(4260)→Z_c⁺(3900)π^-, which may be an evidence of D₁D molecule and can be examined by the forthcoming BESⅢ data in the near future.     

Pure annihilation type decays B0→Ds- K2+ and Bs→Da2 in perturbative QCD approach

We calculate the branching ratios of pure annihilation type decays B⁰→D_s^- K₂^*+ and B_s→Da₂ using the perturbative QCD approach based on k_T factorization. The branching ratios are predicted to be (60.6_{-16.5-10.4-2.1}^{+17.3+4.3+3.2} )× 10^-6 for B⁰→D_s^- K₂^*+, (1.1_-0.4-0.2-0.1^+0.4+0.1+0.1)×10^-6 for B_s→D⁰a₂⁰ and (2.3_-0.8-0.4-0.1^+0.8+0.2+0.1)×10^-6 for B_s→D^-a₂⁺. They are large enough to be measured in the ongoing experiment. Due to the shortage of contributions from penguin operators, there are no direct CP asymmetries for these decays in the Standard Model. We also derive simple relations among these decay channels to reduce theoretical uncertainties for the experiments to test the accuracy of theory and search of new physics signal.     

Nuclear structure of proton-rich unstable nucleus 28P studied by g-factor measurement

Nuclear structure of proton-rich unstable nucleus ²⁸P has been studied by measuring its g-factor for the first time. The g-factor of ²⁸P (I^π=3⁺, T_1/2=270.3 ms) was measured by means of β-NMR technique combined with the new polarization technique for charge exchange reaction product in the intermediate energy heavy ion collisions. The obtained g-factor of g=0.1028(27) is very much quenched from the Schmidt value, but is well reproduced by the shell model (+0.102). In connection with the magnetic moment of the mirror partner and the β-ray transition probability, the orbital angular momenta and intrinsic spins of protons and neutrons have been determined as 〈l_p〉=0.43(29), 〈l_n〉=1.85(29), 〈S_p)=0.28(4), and 〈S_n〉=0.44(4).     

Analysis of Bs→φμ+μ- decay within supersymmetry

Motivated by the rst measurement on B(B_s→φμ⁺μ^-) by the CDF Collaboration, we study the supersymmetric e ects in semi-leptonic B_s→φμ⁺μ^- decay. In our evaluations, we analyze the dependences of the dimuon invariant mass spectrum and the forward-backward asymmetry on relevant supersymmetric couplings in the MSSM with and without R-parity. The analyses show that the new experimental upper limits of B(B_s→φμ⁺μ^-)from the LHCb Collaboration could further improve the bounds on sneutrino exchange couplings and (δ_LL^u)₂₃ as well as (δ_LL,RR^u)₂₃ mass insertion couplings. In addition, within the allowed ranges of relevant couplings under the constraints from B(B_s→φμ⁺μ^-), B(B→K^(*)μ⁺μ^-) and (B_s→φμ⁺μ^-), the dimuon forward-backward asymmetry and the di erential dimuon forward-backward asymmetry of B_s→φμ⁺μ^-are highly sensitive to the squark exchange contribution and the (δ_LL^u)₂₃ mass insertion contribution. The results obtained in this work will be very useful in searching for supersymmetric signals at the LHC.     

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.     

Testing lepton flavor universality in terms of BESⅢ and charm-tau factory data

The recent measurements on R_K and R_π imply that there exists a possible violation of the leptonic flavor universality which is one of the cornerstones of the Standard Model. It is suggested that a mixing between sterile and active neutrinos might induce such a violation. In this work we consider the scenarios with one or two sterile neutrinos to explicitly realize the data while the constraints from the available experiments have been taken into account. Moreover, as indicated in literature, the deviation of the real PMNS matrix from the symmetric patterns may be due to a μ-τ asymmetry, therefore the measurements on R_D(Ds)eμ=Γ(D(D_s)→ e⁺ν_e)/Γ(D(D_s)→ μ⁺ν_μ) and R_D(Ds)μτ=Γ(D(D_s)→ μ⁺ν_μ)/Γ(D(D_s)→ τ⁺ν_τ) (and for some other heavy mesons B^± and B_c etc.) may shed more light on the physics responsible for the violation of the leptonic flavor universality. The data of BESⅢ are available to test the universality and that of future charm-tau factories will provide more accurate information. In this work, we will discuss R_D(Ds)eμ and R_D(Ds)μτ in detail and also briefly consider the cases for B^± and B_c.     

Systematic analysis of DJ(2580), DJ(2650), DJ(2740), DJ(2760), DJ(3000) and DJ(3000) in the D meson family

In this work, we tentatively assign the charmed mesons D_J(2580), D_J^*(2650), D_J(2740), D_J^*(2760), D_J(3000) and D_J^*(3000) observed by the LHCb collaboration according to their spin, parity and masses, then systematically study their strong decays to ground state charmed mesons plus pseudoscalar mesons with the ³P₀ decay model. Based on these studies, we assign the D_J^*(2760) as the 1D(5/2)3^- state, the D_J^*(3000) as the 1F(5/2)2⁺ or 1F(7/2)4⁺ state, the D_J(3000) as the 1F(7/2)3⁺ or 2P(1/2)1⁺ state in the D meson family. As a byproduct, we also study the strong decays of the states 2P(1/2)0⁺, 2P(3/2)2⁺, 3S(1/2)1^-, 3S(1/2)0^- etc, which will be valuable in searching for the partners of these D mesons.     

Study of semileptonic decays Bs→Ds1(2536)lν and Bs→Ds2(2573) lν in the CQM model

Based on the assumption that D_s1(2536) and D_s2(2573) belong to T doublet (1⁺,2⁺), we calculate the semileptonic decays of B_s to D_s1(2536) and D_s2(2573) in terms of the Constituent Quark Meson (CQM) model. For B_s→D_s1(2536)+lν and B_s→D_s2(2573)+lν, the order of magnitude of the obtained branching ratios is 10^－3. Our numerical results of the semileptonic decays of B_s to D_s1(2536) and D_s2(2573) are large, which implies that two semileptonic decays should be seen     

Configuration of the valence neutrons of 17B

The reaction cross section of ¹⁷B on ¹²C target at (43.7±2.4)MeV/u has been measured at the Radioactive Ion Beam Line in Lanzhou (RIBLL). The root-mean-square matter radius (R_rms) was deduced to be (2.92±0.10)fm, while the R_rms of the core and the valence neutron distribution are 2.28fm and 5.98fm respectively. Assuming a ``core plus 2n' structure in ¹⁷B, the mixed configuration of (2s_1/2) and (1d_5/2) of the valence neutrons is studied and the     

Study of the total reaction cross section via QMD

This paper presents a new empirical formula to calculate the average nucleon-nucleon (N-N) collision number for the total reaction cross sections (σ_R). Based on the initial average N-N collision number calculated by quantum molecular dynamics (QMD), quantum correction and Coulomb correction are taken into account within it. The average N-N collision number is calculated by this empirical formula. The total reaction cross sections are obtained within the framework of the Glauber theory. σ_R of ²³Al+¹²C, ²⁴Al+¹²C, ²⁵Al+¹²C, ²⁶Al+¹²C and ²⁷Al+¹²C are calculated in the range of low energy. We also calculate the σ_R of ²⁷Al+¹²C with different incident energies. The calculated σ_R are compared with the experimental data and the results of Glauber theory including the σ_R of both spherical nuclear and deformed nuclear. It is seen that the calculated σ_R are larger than σ_R of spherical nuclear and smaller than σ_R of deformed nuclear, whereas the results agree well with the experimental data in low-energy range.     

∧c^＊ in a coupled-channel baryon-meson scattering

Possible structures and properties of some excited states of Λ_c⁺ dynamically generated in the coupled-channel P-wave meson-baryon scattering are studied by solving the Bethe-Salpeter(BS) equation in the framework of the Chiral Unitary Approach. It is shown that both Λ_c⁺(2765) and Λ_c⁺(2940) could be generated dynamically and could be compound states with multi-configuration molecular-like structures. The couplings of the generated states to various reaction channels are also calculated. Moreover, two highly excited states, Λ_c⁺(3024) and Λ_c⁺(3134), are predicted.     

Particle correlation in p+p collision √sNN=200 GeV in PYTHIA

We calculated the relative abundances of charge hadron, K_S⁰, Λ and Λ in the near-side and away-side cones correlated with triggered high p_T particles in minimum bias in p+p collisions at √s_NN=200 GeV in the PYTHIA model. From the quark and gluon jet events in the PYTHIA model, we have found that the particle yields' different splitting. So the di-hadron correlation in the quark jet events and gluon jet events are also presented. And the particle charge dependance of the di-hadron correlation is extracted from the PYTHIA model. The di-hadron plus and di-hadron minus correlations are similar in the near-side (Δφ~0), but in the away-side, the di-hadron minus correlation seems to be lower. The Hadron-K_S⁰ and －Λ+Λ correlations seem to be differet. We have used a double-Gaussian function to fit those correlation functions and compared the fit parameters.