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.

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The following article has been retracted due to the investigation of complaints received against it.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.

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.

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,andcalculate the electromagnetic coupling constants d,g_1,g_2,and g_3 using the light-cone QCD sum rules.Then we studythe radiative decays B_(s0)-→ B_s~*γ B_(s1)→ B_(sγ),Bs1→ B_s~* γ and B_(s1)→ B_(s0γ),and observe that the widths are rathernarrow.We can search for the (0^+,1^+) strange-bottom mesons in the invariant B_sπ~0 and B_s~*π~0 mass distributions inthe strong decays or in the invariant B_s~* γ and B_s γ mass distributions in the radiative decays.

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.

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.

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.

Influence of σ^(* )and φ Mesons on (A) Hyperon ^(1)S_(0) Superfluidity in Neutron Star Matter

Within the framework of the relativistic mean field theory,we investigate the ^(1)S_(0) superfluidity (SF) of A hyperons in neutron star (NS) matter including σ^(*) and φ mesons.The energy gap of ∧ hyperons is calculated with the Nijmegen one-boson-exchange potentials for a (∧∧) pair. The parameter set we use is in line with the recent experimental data △B_(∧∧) ~ 1.01 ± 0.20_+0.18-0.11 MeV.It is found that with σ^(*) and φ mesons the pairing energy gap △F of ∧ hyperons and the corresponding SF critical temperature T_(C∧) are suppressed.In addition the NS mass range of ∧ hyperon SF is enlarged obviously.

Meson-Nucleon Interaction and Excessive Mesons in Nuclei

The effect of excessive mesons on the meson-nucleon interaction in nuclei is studied.It is shown that even if nonlinear meson interactions are considered,excessive mesons exist in the nuclear ground state(GS)and the GS expectation value of the meson-nucleon interaction Hamiltonian is exactly equal to zero if there are no excessive mesons.

Effective Masses of Mesons and Nucleon in Hot Medium for the Walecka Model

Based on tbe thermo-iield dynamics,the temperature and density dependencies of the elective masses of cr,uj mesons and nucleon in the walecka model have been calcula.ted.The vacuum fluctuation effect is examined.It is found that the vacuum fluctuation is very important and leads to a reduction of cu-meson mass and an enhancement of a-meson mass in hot and dense medium.

Concept of Excessive Mesons in Nuclei

The concept of excessive mesons in nuclei is discussed.Since nucleons are identical particles,it is pointed out that the physical content of a meson distribution around a bound nucleon in nuclei is different from that of a meson clotid around a free nucleon,if the effect of the principle of identity cannot be neglected.The difference is enunciated in detail.

Oscillation Frequencyof𝐵and B𝐵Mesons in a QCD Potential Model with Relativistic Effects

Wavefunction at the origin,with the incorporation of a relativistic effect,leads to singularity in a specific potential model.To regularize the wavefunction,we introduced a short distance scale and used it to estimate the mass and decay constants of Bd and Bs mesons within the QCD potential model.These values were then used to compute the oscillation frequency,ΔmB,of Bd and Bs mesons.The values were found to be in good agreement with experimental and other theoretical values.

Solution of Salpeter Equation for 0^(-) Mesons Involving the Vacuum Condensates in Quantum Chromodynamics

We study the solutions of the salpeter equation for 0^(-) mesons of equal mass quark-antiquark.A potential which was derived in our previour paper in quantum chromodynamics in the background fields is used as the kernel.It includes the perturbative interaction of one gluon exchange and the nonperturbative corrections induced by the quark condensate and the gluon condensate.The results for m_(π),m_(ηc) and m_(ηb) are quite reasonable.

A New Approach to Mesons’ States and Their Dependence on Spin and Isospin: A Mathematical 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 authors’ name: Alireza Heidari and Seyedali Vedad. 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.5 412-419, 2012, has been removed from this site.

On Radiative Decay of Heavy Vector Mesons <i>V</i>&rarr;<i>P&gamma;</i>in the Scalar Strong Interaction Hadron Theory

Radiative decay of heavy ground state vector meson V → P&gamma;is treated semi-classically in the scalar strong interaction hadron theory. The treatment successfully employs the new wave function of the vector meson updated here. The ratio of the available J/ψ and decay rates agrees with prediction. The values of the predicted rates are also in order of magnitude agreement with measurements. These agreements are the only ones directly computed from a first principles’ theory.

Masses and Widths of Light Scalar Mesons in Chiral Perturbation Theory

基于 diquark 模型，我们假设轻分级的介子是 q 22 状态而非 q。chiral 为轻分级的介子的有效 Lagrangian 被构造，并且集体关系被获得：isotriplet (0) 和 isosinglet (f 0) 是最重并且是退化的， isodoublets (κ ) 更重，另外的 isosinglet (σ ) 最轻；并且 2M κ2= M a0 2+ M σ2 。用为 0 和 σ 质量的试验性的价值，我们获得 M κ= 794 兆电子伏，它与试验性的价值一致。然后拿 Γ (00→ ηπ0)= 90 兆电子伏和 Γ (f 00→ π 0π0)= 20 兆电子伏，我们得到 σ 的宽度：Γ (σ → π +π-)= 150 兆电子伏。

Semileptonic Decays of B_s^(**) Mesons into D_(s1) and D_(s2)~* in HQET

In the framework of the heavy quark effective theory,the leading order Isgur-Wise functions relevant to semileptonic decays of the orbitally P-wave excited B s meson states B**s,including the newly found narrow B s1(5830) and B**s2(5840) states,into the(D s1(2536),D*s2(2573)) doublet are calculated from QCD sum rules.With these universal form factors,the decay rates and branching ratios are also estimated.

宇宙线相关的诺贝尔物理学奖

20世纪初,物理学家在对大气导电性的研究中发现了宇宙线,时至今日,宇宙线的发现已过百年.宇宙线是指来自宇宙空间的高能粒子,是人类能够获得的来自太阳系以外的唯一物质样品,包括原子核、电子、光子和中微子,以及其它目前尚未被探测到的未知粒子,它们主要来自宇宙空间中的宇宙线源或者是宇宙线在传播时与空间物质相互作用的产物.在现代物理学发展史中,宇宙线的研究占有重要地位,许多新粒子都是首先在宇宙线研究中发现的,且目前人类已知的最高能量的粒子也来自于宇宙线的观测.作为联系微观粒子和宏观宇宙的桥梁,宇宙线研究既对粒子物理也对天体物理做出了重要贡献.本文重点梳理了在宇宙线研究过程中,荣获的诺贝尔物理学奖,详细介绍了其实验原理、实验仪器和实验成果.