arXiv subjects

Dong-Sheng Du

Publications and source records attributed to Dong-Sheng Du.

At least 19 recordsLinked to original sources

arXiv2012

Determination of $f_0-σ$ mixing angle through $B_s^0 \to J/Ψ~f_0(980)(σ)$ decays

We study $B_s^0 \to J/ψf_0(980)$ decays, the quark content of $f_0(980)$ and the mixing angle of $f_0(980)$ and $σ(600)$. We calculate not only the factorizable contribution in QCD facorization scheme but also the nonfactorizable hard spectator corrections in QCDF and pQCD approach. We get consistent result with the experimental data of $B_s^0 \to J/ψf_0(980)$ and predict the branching ratio of $B_s^0 \to J/ψσ$. We suggest two ways to determine $f_0-σ$ mixing angle $θ$. Using the experimental measured branching ratio of $B_s^0 \to J/ψf_0(980) $, we can get the $f_0-σ$ mixing angle $θ$ with some theoretical uncertainties. We suggest another way to determine $f_0-σ$ mixing angle $θ$ using both of experimental measured decay branching ratios $B_s^0 \to J/ψf_0(980) (σ)$ to avoid theoretical uncertainties.

hep-ph↗

arXiv2009

Probing new physics in $B\to J/Ψπ^0$ decay

We calculate the branching ratio of $B\to J/Ψπ^{0}$ with a mixed formalism that combines the QCD-improved factorization and the perturbative QCD approaches. The result is consistent with experimental data. The quite small penguin contribution in $B\to J/Ψπ^{0}$ decay can be calculated with this method. We suggest two methods to extract the weak phase $β$. One is through the dependence of the mixing induced CP asymmetry $S_{J/Ψπ^{0}}$ on the weak phase$β$, the other is from the relation of the total asymmetry $A_{CP}$ with the weak phase $β$. Our result shows that the deviation $ \bigtriangleup S_{J/ψπ^0}$ of the mixing induced CP asymmetry from $Sin(-2β)$ is of $ \mathcal{O}(10^{-3})$ and has much less uncertainty. The above $ \mathcal{O}(10^{-3})$ deviation can provide a good reference for identifying new physics.

hep-ph↗

arXiv2009

The study of $B\to J/Ψη^{(\prime)}$ decays and determination of $η-η^{\prime}$ mixing angle

We study $B\to J/Ψη^{(\prime)}$ decays and suggest two methods to determine the $η-η^{\prime}$ mixing angle. We calculate not only the factorizable contribution in QCD facorization scheme but also the nonfactorizable hard spectator corrections in pQCD approach. We get the branching ratio of $B\to J/Ψη$ which is consistent with recent experimental data and predict the branching ratio of $B\to J/Ψη^{\prime}$ to be $7.59\times 10^{-6}$. Two methods for determining $η-η^{\prime}$ mixing angle are suggested in this paper. For the first method, we get the $η-η^{\prime}$ mixing angle to be about $-13.1^{\circ}$, which is in consistency with others in the literature. The second method depends on less parameters so can be used to determine the $η-η^{\prime}$ mixing angle with better accuracy but needs, as an input, the branching ratio for $B\to J/Ψη^{\prime}$which should be measured in the near future.

hep-ph↗

arXiv2009

Study of Bc --> J/psi pi, etac pi decays with perturbative QCD approach

The Bc --> J/psi pi, etac pi decays are studied with the perturbative QCD approach. It is found that form factors and branching ratios are sensitive to the parameters w, v, f_J/psi and f_etac, where w and v are the parameters of the charmonium wave functions for Coulomb potential and harmonic oscillator potential, respectively, f_J/psi and f_etac are the decay constants of the J/psi and etac mesons, respectively. The large branching ratios and the clear signals of the final states make the Bc --> J/psi pi, etac pi decays to be the prospective channels for measurements at the hadron colliders

hep-ph↗

arXiv2006

Study of W-exchange Mode $D^0 \to ϕ\bar K^0$

We calculate the branching ratio of $D^0 \to ϕ\bar K^0$ decay using the so-called perturbation QCD approach based on $k_T$ factorization. Our result shows this branching ratio is $(8.7 \pm1.4)\times 10^{-3}$, which is consistent with experimental data. We hope the CLEO-C and BES-III can measure it more accurately, which will help us to understand QCD dynamics and $D$ meson weak decays.

hep-ph↗

arXiv2005

Prediction of $B_c\to Dπ$ in the pQCD approach

We investigate the branching ratios and direct CP asymmetries of $B_c^+\to D^0π^+$ and $B_c^+\to D^+π^0$ decays in the PQCD approach. All the diagrams with emission topology or annihilation topology are calculated strictly. A branching ratio of $10^{-6}$ and $10^{-7}$ for $B_c^+\to D^0π^+$ and $B_c^+\to D^+π^0$ decay is predicted, respectively. Because of the different weak phase and strong phase from penguin operator and two kinds of tree operator contributions, we predict a possible large direct CP violation: $A^{\rm dir}_{cp} (B_c^\pm \to D^0 π^\pm)\approx -50%$ and $A^{\rm dir}_{cp} (B_c^\pm \to D^\pm π^0)\approx 25%$ when $γ=55^\circ$, which can be tested in the coming LHC.

hep-ph↗

arXiv2005

Mass and Decay Constant of $I=1/2$ Scalar Meson In QCD Sum Rule

We calculate the mass and decay constant of $I=1/2$ scalar mesons composed of quark-antiquark pairs based on QCD sum rule. The quauk-antiquark pairs can be $s\bar{q}$ or $q\bar{s}$ ($q=u,d$) in quark model, the quantum numbers of spin and orbital angular momentum are S=1, L=1. We obtain the mass of the ground sate in this channel is $1.410\pm 0.049$GeV. This result favors that $K_{0}^{\ast}(1430)$ is the lowest scalar state of $s\bar{q}$ or $q\bar{s}$. We also predict the first excited scalar resonance of $s\bar{q}$ is larger than 2.0 GeV.

hep-ph↗

arXiv2004

Form Factors and semileptonic decay of $D_s^+\to ϕ\bar{\ell}ν$ from QCD sum rule

We calculate $D_s^+\to ϕ$ transition form factors $V$, $A_0$, $A_1$ and $A_2$, and study semileptonic decay of $D_s^+\to ϕ\bar{\ell}ν$ based on QCD sum rule method. We compare our results of the ratios of $V(0)/A_1(0)$, $A_2(0)/A_1(0)$, $Γ_L/Γ_T$, and the total decay branching ratio of $D_s^+\to ϕ\bar{\ell}ν$ with experimental data, and find that they are consistent.

hep-ph↗

arXiv2002

The one loop renormalization of the effective Higgs sector and its implications

We study the one-loop renormalization the standard model with anomalous Higgs couplings ($O(p^2)$) by using the background field method, and provide the whole divergence structure at one loop level. The one-loop divergence structure indicates that, under the quantum corrections, only after taking into account the mass terms of Z bosons ($O(p^2)$) and the whole bosonic sector of the electroweak chiral Lagrangian ($O(p^4)$), can the effective Lagrangian be complete up to $O(p^4)$.

hep-ph↗

arXiv2002

The renormalization of the effective gauge Lagrangian with spontaneous symmetry breaking: the U(1) case

We study the renormalization of the nonlinear effective U(1) Lagrangian up to $O(p^4)$ with spontaneous symmetry breaking. The problems of the quartic divergences and of the truncation of infinite divergence tower are addressed. The renormalization group equations of the effective Lagrangian are derived, which make it possible to get the leading logarithm corrections of the heavy degree of freedom, even if the effective and full theories are matched at tree level. The method we use in the U(1) case can easily be extended to study the non-Abelian effective theories and the electroweak chiral Lagrangian.

hep-ph↗

arXiv2002

The renormalization of the effective Lagrangian with spontaneous symmetry breaking: the SU(2) case

We study the renormalization of the nonlinear effective SU(2) Lagrangian up to $O(p^4)$ with spontaneous symmetry breaking. The Stueckelberg transformation, the background field gauge, the Schwinger proper time and heat kernel method, and the covariant short distance expansion technology, guarantee the gauge covariance and incooperate the Ward indentities in our calculations. The renormalization group equations of the effective couplings are derived and analyzed. We find that the difference between the results gotten from the direct method and the renormalization group equation method can be quite large when the Higgs scalar is far below its decoupling limit.

hep-ph↗

arXiv2002

Final State Interactions in $D \to PP$ decays

The two-body nonleptonic charmed meson decays into two pseudoscalar mesons are studied using one-particle-exchange method. The effects of the final state interactions are analyzed through the strong phases extracted from the experimental data.

hep-ph↗

arXiv2002

D-->PV decays with final state interactions

We employ one-particle-exchange method to study D-->PV decays in D-->K ρ, πK*, πρprocesses. Taking into account a strong phase and considering nonfactorizable effect, we can get good results consistent with the experimental data. Nonfactorizable effect is not always large, but in some cases, the nonfactorizable effect is nececcesary to accommodate the experimental data. Strong phase is approximately SU(3) flavour symmetric.

hep-ph↗

arXiv2002

$D \to ππ$ decays with Final State Interactions

We study $D \to ππ$ decays with final state interactions considered in one-particle-exchange method. A clear physical picture for final state interactions based on quark and hadronic level diagrams is presented. A strong phase is introduced for hadronic effective couplings, which is crucial for explaining the experimental data of $D^+\to π^+π^0$, $D^0\to π^+π^-$, and $D^0\to π^0π^0$. Rescattering effects between different $D$ decay channels are usually large. They are important for obtaining correct branching ratios for $D\to ππ$ decays in theoretical calculation.

hep-ph↗

arXiv2002

Brane fluctuation and the electroweak chiral Lagrangian

We use the external field method to study the electroweak chiral Lagrangian of the extra dimension model with brane fluctuation. Under the assumption that the contact terms between the matters of the standard model and KK excitations are heavily suppressed, we use the standard procedure to integrate out the quantum fields of KK excitations and the equation of motion to eliminate the classic fields of KK excitations. At one-loop level, we find that up to the order $O(p^4)$, due to the momentum conservation of the fifth dimension and the gauge symmetry of the zero modes, there is no constraint on the size of extra dimension. This result is consistent with the decoupling theorem. However, meaningful constraints can come from those operators in $O(p^6)$, which can contribute considerably to some anomalous vector couplings and can be accessible in the LC and LHC.

hep-ph↗

arXiv2002

Is the truncated SU(N) non-Abelian gauge theory in extra dimensions renormalizable?

In this letter we show that in the extra dimension model, contrary to the widely accepted conception, the simply truncated $ϕ^4$ and non-Abelian SU(N) Kaluza-Klein theories are not renormalizable, i.e. the tree level relations of the effective theories can not sustain the quantum corrections. The breaking down of the tree level relations of the effective theories can be traced back to several factors: the breaking of the higher dimension Lorentz symmetry and higher dimension gauge symmetry, interactions assumed in the underlying Lagrangians, and the dimension reduction and rescaling procedure.

hep-th↗

arXiv2002

Sudakov effects in BBNS approach

The end-point singularity is an unsolved problem in BBNS approach. Incorporating the partonic transverse momentum and the Sudakov form factor, this problem can be solved model-independently. We discuss the Sudakov effects in BBNS approach. The BBNS approach is compared with the modified PQCD approach. The main idea of Sudakov form factor is briefly discussed. Our conclusion is that the twist-3 contribution for the hard spectator scattering is numerically not important in $B\to ππ$ decays, compared with the twist-2 contribution.

hep-ph↗

arXiv2000

Test of CPT symmetry in cascade decays

Cascade mixing provides an elegant place to study the $B^0-\bar{B^0}$ mixing. We use this idea to study the CPT violation caused by $B^0-\bar{B^0}$ mixing. An approximation method is adopted to treat the two complex $B^0-\bar{B^0}$ mixing parameters $θ$ and $ϕ$. A procedure to extract the parameters $θ$ and $ϕ$ is suggested. The feasibility of exploring the CPT violation and determining of $θ$ and $ϕ$ in the future B-factories and LHC-B is discussed.

hep-ph↗