e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) Cross Sections and the Λ_(c)^(+) Electromagnetic Form Factors within the Extended Vector Meson Dominance Model

Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model parameters are determined by fitting them to the cross sections of the process𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) and the magnetic form factor|G_(M)|of Λ_(c)^(+) .By considering four charmonium-like states,called𝜓(4500),𝜓(4660),𝜓(4790),and𝜓(4900),we can well describe the current data on the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction from the reaction threshold up to 4.96 GeV.In addition to the total cross sections and|𝐺M|,the ratio|G_(E)/G_(M)|and the effective form factor|Geff|for Λ_(c)^(+) 𝑐are also calculated,and found that these calculations are consistent with the experimental data.Within the fitted model parameters,we have also estimated the charge radius of the charmed Λ_(c)^(+) baryon.

Vector meson spin alignment by the strong force field

Observation of unexpectedly large global spin alignment of φ vector mesons in non-central heavy-ion collisions by STAR experiment may reveal the non-perturbative nature of quark interaction in hot matter through fluctuating strong force field with short correlation length.

On the mass of the ss^- member of the 1^3D1 meson nonet

In the framework of Regge phenomenology and meson meson mixing, this paper estimates the mass of isoscalar state （ss^-） of the 1^3D1 meson nonet, and the results given by two different approaches are 1735.51 ± 59MeV and 1730.29 ±46.SMeV.

The Theoretical Value of Mass of the Light <i>η</i>-Meson via the Quarks’ Geometric Model

Highlighting a golden triangular form in u and d quarks (Quark Geometric Model), we build the geometric structures of light meson η and individualize its decays and spin. By the structure equations describing mesons, we determine a mathematic procedure to calculate the theoretical value of the mass of light mesons η.

Study of the Bc—Meson Lifetime

We in terms of optical theorem estimate the lifetime of Bc meson with the parameters which are determined by fitting the data for the lifetimes and inclusive semileptonic decays of various B and D mesons. In the estimation, we find that the bound-state effects are important, and take them into account carefully in the framework which attributes the effects to the effective masses of the decay heavy quarks in the inclusive processes. We also find that to Bc lifetime the penguin contribution is enhanced due to possible interference between the penguin and the 'tree part' c1O1 + c2O2.

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.

The Theoretical Spectrum of Mass of the Light Mesons without Strangeness via the Quarks’ Geometric Model

Using the “Aureum Geometric Model” (AGM) of quarks, we formulate the structure equations describing mesons and, by a mathematic procedure, we calculate the theoretical spectrum of mass values of light mesons without strangeness.

The Structure Functions in the Weak and Semileptonic Decay of Meson B to the Mesons D and D*: A Computational Study

The following article has been retracted due to the investigation of complaints received against it. Mr. Mohammadali Ghorbani (corresponding author and also the last author) cheated the author’s name: Alireza Heidari. The scientific community takes a very strong view on this matter and we treat all unethical behavior such as plagiarism seriously. This paper published in Vol.3 No.2, 208-213, 2012, has been removed from this site.

The mass of the isodoublet of the 2^1S0 meson nonet revisited

In the qq quark model, the states π（1300）, η（1295） and η（1475） are assigned as the 2^1S0 meson nonet. The mass of the isodoublet remains interesting and needs further confirmation in experiments. This paper employs the phenomenological trajectory on the （N, M^2）-plot and meson meson mixing methods to calculate the mass of this state, the calculated results are 1341 MeV and 1311.58 ± 59 MeV respectively. These predictions can be compared with experiments in the future.

Non-extensive statistical distributions of charmed meson production in Pb-Pb and pp(p)collisions

The mid-rapidity transverse momentum spectra of charmed mesons in Pb–Pb and pp(p)collisions are analyzed using the Tsallis–Pareto distribution derived from non-extensive statistics.We provide uniform descriptions of both small and large systems over a wide range of collision energies and hadron transverse momenta.By establishing the relationship between the event multiplicity and Tsallis parameters,we observe that there is a signifi-cant linear relationship between the thermal temperature and Tsallis q parameter in Pb–Pb collisions at √sNN=2.76 TeV and 5.02 TeV.Further,the slope of the T–(q-1)parameter plot is positively correlated with the hadron mass.In addition,charmed mesons have a higher thermal temperature than light hadrons at the same q-1,indicat-ing that the charm flavor requires a higher temperature to reach the same degree of non-extensivity as light flavors in heavy-ion collisions.The same fit is applied to the trans-verse momentum spectra of charmed mesons in pp(p)collisions over a large energy range using the Tsallis–Pareto distribution.It is found that the thermal temperature increases with system energy,whereas the q parameter becomes saturated at the pp(p)limit,q-1=0.142±0.010.In addition,the results of most peripheral Pb–Pb collisions are found to approach the pp(p)limit,which suggests that more peripheral heavy-ion collisions are less affected by the medium and more similar to pp(p)collisions.

Study on Production of Exotic 0^＋ Meson D＇^＊aj（2317） in Decays of ψ（4415）

The newly observed D^＊aj family containing D^＊aj（2317）, Daj（2460）, and Daj（2632） attracts great interests. Determining their structures may be an important task for both theorists and experimentalists. In this work we use a non-relativistic model （the harmonic oscillator model） to evaluate the production rate of D^＊aj （2317） from the decays of ψ（4415）. For a comparison, we a/so employ the widely adopted heavy quark effective theory to repeat the calculation. We lind that the rate is sizable and may be observed at BES III and CLEO, if it is a p-wave excited state of Da（1968）. Unfortunately, the other two members of the family cannot be observed through decays of charmonia, because of the constraints from the final state phase space.

Vector Meson Electro-production in Pomeron Exchange Model

Based on Pomeron exchange model, elastic production of vector meson in electro-proton interaction is investigated with both linear and non-linear Pomeron trajectory. A numerical calculation for J/psi production is performed. The effect of the energy scale so and photon virtuality Q(2) on differential cross section are also predicted. A good agreement with experimental data is obtained. Our conclusions are that the Pomeron exchange model is a successful description of J/psi electro-production, the dependence of the differential cross sections on Q2 is negligible, the linear trajectory is a good approximation to non-linearity of the Pomeron trajectory, and the value of the energy scale parameter so is dependent on the momentum transfer, namely its effect is moderate at low momentum transfer but it causes no difference at high momentum transfer vertical bar t vertical bar >= 1.25 GeV2.

Incompressibility of Nuclear Matter in a Quark-Meson Coupling Model

The quark meson coupling model is used to investigate the correlation between thenuclear incompressibility K and the third order derivitive K′ of the nuclear matter saturationcurve,the temperature and entropy dependence of the nuclear

Chiral Lagrangian Treatment of 0^＋＋ Mesons and 0^＋＋ Glueballs

Within the framework of a nonlinear chiral Lagrangian the mass spectra and the decay properties of 0^＋＋ states below 2 GeV are studied. Assuming that f0（980）, a0（980）, K0（1430）, and f0（1500） comprise an SU（3） nonet, we make a detailed prediction about the static properties of the 0^＋＋ mesons. The substructure analysis of these states in terms of two- and four-quark components as well as a glueball component is carried out. We also consider the interaction Lagrangian and provide a preliminary study of the strong and radiative decays of the 0＋＋ mesons. The scalar glueball masses and partial widths are also presented. In view of the fact that few data of 0＋＋ mesons are clearly given in the present PDG （Particle Data Group） list and that the four-quark content of mesons is a hot issue both experimentally and theoretically, the predicted results of the paper may be helpful for upcoming experimental and theoretical studies of these mesons.

The Effects of δ Meson on the Neutron Star Cooling

In the framework of the relativistic mean field theory, the isovector scalar interaction is considered by exchanging δ meson to study the influence of δ meson on the cooling properties of neutron star matter. The calculation results show that with the inclusion of δ meson, the neutrino emissivity of the direct Urca processes increases, and thus enhances the cooling of neutron star matter. When strong proton superfluidity is considered, the theoretical cooling curves agree with the observed thermal radiation for isolated neutron stars.

Anisotropic emission of charged mesons and structure characteristic of emission source in heavy ion collisions at 1-2A GeV

Angular distributions of pious and kaons produced in heavy ion collisions at the low-energy end of high energies （1-2 A GeV） have been investigated by using a multisource ideal gas model. The model covers the expansions and movements of the emission sources, and it is related to the collective flows. By using the analytic expression and the Monte Carlo method, the azimuthal and polar angle distributions of mesons are calculated by the model and compared with the experimental data of the KaoS Collaboration.

On Excited Meson Spectra in the Scalar Strong Interaction Hadron Theory

Meson spectra have been treated earlier in the scalar strong interaction hadron theory, choosing the Coulomb and linear type of potentials, neglecting the quadratic one. The spectra of ground state pseudoscalar and vector mesons were adequately accounted for but not that of the excited mesons. Here, the quadratic potential replaces the Coulomb one and the same ground state meson spectra were recovered. Also, the masses of low-lying radially excited pseudoscalar and vector mesons were found to be 4% - 18% smaller than the measured ones. Here, the linear type of potential, by itself of nonlinear nature, has been neglected. For some orbitally excited pseudoscalar mesons, the difference is 14% - 38%. The discrepancies are tentatively attributed to the neglected nonlinear potential, which is expected to increase with meson mass, as can be seen in the tables below.

Meson Effects on the Chiral Condensate at Finite Density

Meson corrections on the chiral condensate up to next-to-leading order in a 1/Nc expansion at finite densityare investigated in the NJL model with explicit chiral symmetry breaking. Compared with mean-field results, the chiralphase transition is still of the first order while the properties near the critical density for chiral phase transition are foundto change significantly.

Tensor Couplings of ω- and ρ-Mesons with Nucleons in a Derivative Scalar Coupling Model for Finite Nuclei

Theω-andρ-meson tensor couplings to nucleons in a derivative scalar coupling model for finite nuclei are investigated.The influences of the tensor couplings on the binding energies per nucleon,the root-mean-square charge radii,spin-orbit splittings and single particle energies are discussed.The obtained results show that the spin-orbit splittings for finite nuclei are more sensitive to theω-meson tensor coupling.

One-Meson Exchange in Quantized Two-Breather Model

Instead of two-kink system,two-breather system under sum ansatz is quantized.A covariant meson-breather interaction to the one-meson range and to the leading nonstatic order is obtained.All of the results depend on breather internal variable θ.