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1.
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.  相似文献   

2.
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.  相似文献   

3.
The positive parity scalar D * s0 (2317) and axial-vector D * s1 (2460) charmed strange mesons are generated by coupled-channel dynamics through the s-wave scattering of Goldstone bosons off the pseudoscalar and vector D(D s )-meson ground states.The specific masses of these states are obtained as a consequence of the attraction arising from the Weinberg-Tomozawa interaction in the chiral Lagrangian.Chiral corrections to order Q 2 χ are calculated and found to be small.The D * s0 (2317) and D * s1 (2460) mesons decay either strongly into the isospin-violating π 0 D s and π 0 D ? s channels or electromagnetically.We show that the π 0-η and (K^ 0 D ^+-K^ + D^ 0 ) mixings act constructively to generate strong widths of the order of 140 keV and emphasize the sensitivity of this value to the KD component of the states.The one-loop contribution to the radiative decay amplitudes of scalar and axial-vector states is calculated using the electromagnetic Lagrangian to chiral order Q 2 χ .We show the importance of taking into account processes involving light vector mesons explicitly in the dynamics of electromagnetic decays.The radiative width are sensitive to both η D s and KD components,hence providing information complementary to the strong widths on the positive parity D s-meson structure.  相似文献   

4.
Hadron molecules     
We discuss a possible interpretation of the open charm mesons D*s0 (2317),D s1 (2460) and the hidden charm mesons X(3872),Y(3940) and Y(4140) as hadron molecules.Using a phenomenological Lagrangian approach we review the strong and radiative decays of the D* s0 (2317) and D s1 (2460) states.The X(3872) is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration.Determing the radiative (γJ/ψ and γψ(2s)) and strong (J/ψ2π and J/ψ3π) decay modes we show that the present experimental observation is consistent with the molecular structure assumption of the X(3872).Finally,we give evidence for molecular interpretations of the Y(3940) and Y(4140) related to the observed strong decay modes J/ψ+ω or J/ψ+φ,respectively.  相似文献   

5.
Based on the two mutually conjugate entangled state representations |ξ〉 and |η〉, we propose an integration transformation in ξ - η phase space ∫∫ d^2ξd^2η/π^2e^(ξ-η)(η^* -v^*)-(η-v)(ξ^*-μ^*)F(ξ^*,μ^*) F(ξ, η)≡D(μ,v), and its inverse trans- formation, which possesses some well-behaved transformation properties, such as being invertible and the Parseval theorem. This integral transformation is a convolution, where one of the factors is fixed as a special normalized exponential function. We generalize this transformation to a quantum mechanical case and apply it to studying the Weyl ordering of bipartite operators, regarding to (Q1 -Q2) (P1 - P2) ordered and simultaneously (P1 + P2) (Q1+ Q2) ordered operators.  相似文献   

6.
王登霞  张爱林 《中国物理 C》2010,34(9):1387-1389
The spectrum of D s mesons is systematically studied in a semi-classic mass loaded flux tube model.D s in D-wave multiplets is predicted to have lower masses in comparison with most theoretical predictions.D sJ (2632) +,D s1 (2700) ±,D sJ (2860) + and D sJ (3040) + are interpreted in the constituent quark model.  相似文献   

7.
Low-energy scattering of D ^*+ and D1^0 meson is studied using quenched lattice QCD with improved lattice actions on anisotropic lattices.The threshold scattering parameters,namely the scattering length a 0 and the effective range r 0,for the s-wave scattering in J P = 0 - channel are extracted: a 0 = 2.52(47) fm and r 0 = 0.7(1) fm.It is argued that,albeit the interaction between the two charmed mesons being attractive,it is unlikely that they can form a shallow bound state in this channel.Our calculation provides some useful information on the nature of the newly discovered resonance-like structure Z + (4430) by the Belle Collaboration.  相似文献   

8.
We correct an inaccurate result of previous work on the Feynman propagator in position space of a free Dirac field in (3 + 1)-dimensional spacetime; we derive the generalized analytic formulas of both the scalar Feynman propagator and the spinor Feynman propagator in position space in arbitrary (D + 1)- dimensional spacetime; and we further find a recurrence relation among the spinor Feynman propagator in (D+1)-dimensional spacetime and the scalar Feynman propagators in (D+1)-, (D-1)- and (D+3)-dimensional spacetimes.  相似文献   

9.
Using the relativistic Bethe-Salpeter method, the electron energy spectrum and the semileptonic decay widths of B^0 → Ds^- e+ve and B^0 → Ds^*-e+ve are calculated. We obtain a large branching fraction Br(Bs → Dseve) = (2.85 ± 0.35)% and Br(Bs→ D^*s eue) = (7.09 ±0.88)%, which can be easily detected in future experiments.  相似文献   

10.
Cross sections of electron-loss in H(1s)+ H(1s) collisions and total collisional destruction of H(2s) in H(1s) 4- H(2s) collisions are calculatted by four-body classical-trajectory Monte Caylo (CTMC) method and compared with previous theoretical and experimental data over the energy range of 4-100 keV. For the former a good agreement is obtained within different four-body CTMC calculations, and for the incident energy Ep 〉 10 keV, comparison with the experimental data shows a better agreement than the results calculated by the impact parameter approx- imation. For the latter, our theory predicts the correct experimental behaviour, and the discrepancies between our results and experimental ones are less than 30%. Based on the successive comparison with experiments, the cross sections for excitation to H(2p), single- and double-ionization and H- formation in H(2s)+H(2s) collisions are calculated in the energy range of 4-100 keV for the first time, and compared with those in H(1s)+H(1s) and H(1s)+U(2s) collisions.  相似文献   

11.
This paper applies the symmetry-aziapted-cluster/symmetry-adapted-cluster configuration-interaction (SAC/SACCI) method to optimize the structures for X^1∑^+, A^1 Ⅱ and C^1 ∑^- states of SiO molecule with the basis sets D95++, 6-311++G and 6-311++G^**. Comparing the obtained results with the experiments, it gets the conclusion that the basis set 6-311++G^** is most suitable for the optimal structure calculations of X^1.∑^+, A^Ⅱ and C^1∑^- states of SiO molecule. The whole potential energy curves for these electronic states are further scanned by using SAC/6-311++G^** method for the ground state and SAC-CI/6-311++G^** method for the excited states, then use a least square method to fit Murrell~Sorbie functions, at last the spectroscopic constants and force constants are calculated, which are in good agreement with the experimental data.  相似文献   

12.
We systematically investigate the mass spectra of {Qs}{Q(')s} molecular states in the framework of QCD sum rules. The interpolating currents representing the molecular states are proposed. Technically, contributions of the operators up to dimension six are included in operator product expansion (OPE). The masses for molecular states with various {Qs}{Q(')s} configurations are presented. The result 4.36 ± 0.08 Ge V for theDs* Ds0- * molecular state is consistent with the mass 4350+4.6 -5.1± 0.7 MeV of the newly observed X(4350), which could support X(4350) interpreted as a D*D*so molecular state.  相似文献   

13.
刘翔 《中国物理 C》2010,34(9):1405-1407
In my talk,we present the dynamical study of Y(4140) and Y(3930) under the D*s D*s and D* D* molecular assignments respectively.The importance to theoretically and experimentally study their open-charm decay,hidden-charm decay,radiative decay and double-photon decay is proposed combing with the theoretical calculation of the decay behavior of Y(4140) and Y(3930).According to the recent new experimental progress made by Belle,we further indicate the reasonability of molecular explanation to Y(4140).Another event cluster around 4270 MeV in the J/ψφ invariant mass spectrum of B → KJ/ψφ can provide us more hints to reveal the creation mechanism of molecular structure in B meson decay,which will be helpful to clarify the underlying structure of Y(4140) and Y(3930).  相似文献   

14.
15.
We present the comaprative study of semileptonic and leptonic decays of Ds, D±and D0meson(D →M l+-αl-β, D → l+αlβ, D → l+αvα;α,β=e,μ) within the framework of R-parity violating the( Rp) Minimal Supersymmetric Standard Model(MSSM). The comparison shows that combination and product couplings,(λβiα λ* ij qor λβqkλ*αj k)contribution to the branching fractions of the said processes(under consideration) is consistent with or comparable to the experimental measurements in most of the cases. However, some cases exist where these contributions are highly suppressed. We identify such cases in our analysis and single out the important ones suitable for exploring in the future and current experiments.  相似文献   

16.
The initial single pion emission (ISPE) mechanism is applied to the processes r(5S)→πB(*)B-(*), whose details have been recently reported at ICHEP2012, and we obtain reasonable agreement with Bell's measurements; that is, we succeed in reproducing the enhancement structures of Zb(10610) and Zb(10650). Inspired by this success, we also predict the corresponding enhancement structures in open charm oue-pion decays of higher charmonia near the thresholds of D*D- and D*D-*.  相似文献   

17.
We present a study on the gyroresonant interaction particles in multi-ion (H^+, He^+, and O^+) plasmas between electromagnetic ion cyclotron waves and ring current We provide a first evaluation of the bounce-averaged pitch angle diffusion coefficient 〈Dαα〉 for three typical energies of 50, 100 and 150keV at L ≈ 3.5, the heart of the symmetrical ring current. We show that in the H^+-band and He^+-band, 〈Dαα〉 can approach - 10^-4 s^-1 for ion H^+, and - 5 × 10^-5 s^-1 /or ion He^+; meanwhile, in the O^+-band, 〈Dαα〉 can reach - 10^-5 s^-1 for ions He^+ and O^+. The results above show that the EMIC wave can efficiently produce precipitation loss of energetic (- 100 keV) ions (H^+, He^+ and even O^+), and such a wave tends to be a serious candidate responsible for the ring current decay.  相似文献   

18.
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.  相似文献   

19.
Abstract The possibility of QQqq heavy-light four-quark bound states has been analyzed by means of the chiral SU(3) quark model, where Q is the heavy quark (c or b) and q is the light quark (u, d, or s). We obtain a bound state for the bbnn configuration with quantum number JR=1^+, I = 0 and for the ccnn (JR=1^+, I=O) configuration, which is not bound but slightly above the D^* D^* threshold (n is u or d quark). Meanwhile, we also conclude that a weakly bound state in bbnn system can also be found without considering the ehiral quark interactions between the two light quarks, yet its binding energy is weaker than that with the chiral quark interactions.  相似文献   

20.
We focus on the investigation of the spatial distribution and temporal evolution of N2(A3Σ+u, ν=0) in a very early afterglow of a pulsed dc nitrogen discharge. The results indicate that a fast quenching process of N2(A3Σ+u, ν=0) exists in the very early afterglow. We study the dependence of this fast quenching process on the discharge pressure 20–40 torr. It seems that this fast quenching behavior of N2(A3Σ+u, ν=0) found in our experiment can be ascribed to the combined action of pooling reaction and collisions with N atoms through N2(A3Σ+u)+N2(A3Σ+u)→ N2*+N2(N2*=N2(B3Πg, C3Πu, C'3Πu, C"5Πu)) and N2(A3Σ+u)+N(4S)→N(2P)+N2, respectively. Meanwhile, the decay studies of N2(A3Σ+u, ν=0) near the anode and cathode infer that the production of N(4S) atoms does not distribute uniformly along the axis of the discharge gap at relatively low pressure, and this effect becomes gradually inconspicuous with the increasing discharge pressure.  相似文献   

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