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.

Chiral effective Lagrangian for excited heavy-light mesons from QCD

We derive the chiral effective Lagrangian for excited heavy-light mesons from QCD under proper approximations.We focus on the chiral partners with j_(l)^(P)=3+/2 and j_(l)^(P)=3-/2 which amounts to(1^(+),2^(+))and(1^(-),2^(-))states respectively.The low energy constants including the masses of the chiral partners are calculated.The calculated spectrum for the excited mesons are found roughly consistent with experimental data.In addition,our results indicate that quantum numbers of B_(J)(5970)can be identified with 1^(-)or 2^(-).

Masses of heavy-light mesons in Regge phenomenology

The masses of some orbitally and radially excited heavy-light mesons are calculated in Regge phenomenol- ogy. 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＇1（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.

Possible hadronic molecular states composed of S-wave heavy-light mesons

We perform a systematical study of possible molecular states composed of the S wave heavy light mesons,where the S–D mixing and η-η＇ mixing are explicitly included.Our calculation indicates that the observed X（3872） could be a loosely shallow molecular state composed of D＊＋ h.c,while neither Z_c（3900）/Z_c（4020） nor Z_b（10610）/Z_b（10650） is supported to be a molecule.Some observed possible molecular states are predicted,which could be searched for by further experimental measurements.

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.

Heavy-light mesons in a relativistic model

We study the heavy-light mesons in a relativistic model, which is derived from the Bethe-Salpeter equation by applying the Foldy-Wouthuysen transformation to the heavy quark. The kernel we choose is based on scalar confinement and vector Coulomb potentials. The transverse interaction of the gluon exchange is also taken into account in this model. The spectra and wave functions of D, Ds, B, Bs meson states are obtained. The spectra are calculated up to the order of 1/mQ, and wave functions are treated to leading order.

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.

An Original Didactic about Standard Model (Geometric Model of Particle: The Quarks)

This work shows a didactic model representative of the quarks described in the Standard Model (SM). In the model, particles are represented by structures corresponding to geometric shapes of coupled quantum oscillators (GMP). From these didactic hypotheses emerges an in-depth phenomenology of particles (quarks) fully compatible with that of SM, showing, besides, that the number of possible quarks is six.

Mass Increase with Strong and Gravitational Potentials, and Mass Defect with Electromagnetic Potential

The proposal is “mass increases due to strong and gravitational potentials, while it decreases due to Electromagnetic potential”. This proposal explains the big difference in mass between hadrons (protons, neutrons, & mesons) and their components (quarks), mass difference between nucleus and its individual components (protons and neutrons), massless of gamma photons, abnormal masses of mesons and bosons, and the excess in galaxy masses (dark matter). Also, this proposal shows the exact relation between mass and energy: Strong Potential=−3.04mc2| Electric Potential |=−5.57×10−3mc2Gravitational Potential=−1.22×10−7mc2where m represents the excess in mass due to strong potential, or gravitational potential and represents the decrease in mass due to electromagnetic potential. Released energy here equals potential energy and doesn’t equal decrease in mass using the formula E = mc2. Released energy is transferred to heat, photons, kinetic energy… Finally, proposal will try to describe the relation between photon energy and mass of its components using the general equation of kinetic energy: Photon Energy=1/2mc2m is the sum of the individual masses of its components, while the total mass of photon is zero.

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.

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.

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 c liftime the peguin contribution is enhanced due to possible interference between peguin and the tree part c1O1+c2O2,.

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.

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.

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.

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.

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

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/ψ production is performed. The effect of the energy scale so and photon virtuality Q2 on differential cross section are also predicted. Agood agreement with experimental data is obtained. Our conclusions are that the Pomeron exchange model is a successful description of J/ψ 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 | t |≥ 1.25 GeV2.