124490688
THE VIRTUAL EXCHANGE OF PSEUDOSCALAR MESONS IN THE MIT BAG MODEL
In this paper the virtual exchange effect of pseudoscalar mesons in the MIT bag model is discussed and the mass spectrum of hadrons, the magnetic moments and the mean square values of charge radius are calculated. It is pointed out that our model can preserve and improve the static properties of the MIT bag model and provide an explanation for the origin of the meson cloud outside baryons.
124473583
Partonic Structure of the Pomeron in the Modified GLR Equation
The gluon recombination effect in the pomeron is studied by using the modified Gribov–Levin–Ryskin evolution equation. We find that the measured parton distributions in the pomeron can be generated dynamically from a purely gluonic input on assuming a small size for the pomeron.
124556870
A New Effect in the QCD Fusion of Nuclear Partons
The parton fusion in nucleus at the leading order of recombination is investigated based on perturbative QCD. We compute various cut diagrams including the nuclear parton fusion, and find that the parton-fusion effects depend on the nuclear QCD structure.
119716730
A twist-4 effect in the parton evolution processes
Recently, a research group reported that they can fit the F2 data well by using the Altarelli-Parisi evolution equation with a valence-like initial gluon distribution, which means that we need not consider the high twist effects in the proton. In this letter, we point out that their valence-like initial gluon distribution is unreasonable for the proton structure function. With the reasonable initial distributions, we find that the high twist corrections to the Altarelli-Parisi evolution equation is necessary.
122365434
Bag skin effect for Friedberg-Lee model
Importance of the bag skin effect to determine the parameters of the Friedberg-Lee model is pointed out. The European Muon Collaboration (EMC) effect regarded as a bag skin effect can be used to determine the parameters of this model.
18244927
Nuclear Shadowing and Antishadowing in a Unitarized BFKL Equation
The nuclear shadowing and antishadowing effects are explained by a unitarized BFKL equation. The Q2and x-variations of the nuclear parton distributions are detailed based on the level of the unintegrated gluon distribution. In particular, the asymptotical behavior of the unintegrated gluon distribution near the saturation limit in nuclear targets is studied. Our results in the nuclear targets are insensitive to the input distributions if the parameters are fixed by the data of a free proton. PACS numbers: 13.60.Hb; 12.38.Bx. keywords: nuclear shadowing and antishadowing; unintegrated gluon distribution in nuclei; QCD evolution equation Supported by National Natural Science Foundation of China 10135060, 10475028 and 10205004. Corresponding author, E-mail: weizhu @mail.ecnu.edu.cn
118982861
Sudakov form factor in effective field theory
We discuss the Sudakov form factor in the framework of the soft-collinear effective theory. The running of the short distance coefficient function from high to low scale gives the summation of Sudakov logarithms to all orders. Our discussions concentrate on the factorization and derivation of the renormalization group equation from the effective theory point of view. The intuitive interpretation of the renormalization group method is discussed. We compared our method with other resummation approaches in the literatures.
122147995
Hyperon–hyperon interaction in relativistic mean field model
By using the new experimental data of �� potential, this paper has performed a full calculation for strange hadronic matter with different strangeness contents as well as its consequences on the global properties of neutron star matter in relativistic mean field model. It finds that the new weak hyperon–hyperon interaction makes the equations of state much stiffer than the result of the previous strong hyperon–hyperon interaction, and even stiffer than the result without consideration of hyperon–hyperon interaction. This new hyperon–hyperon interaction results in a maximum mass of 1.75M⊙ (where M⊙ stands for the mass of the Sun), about 0.2–0.5M⊙ larger than the previous prediction with the presence of hyperons. After examining carefully the onset densities of kaon condensation it finds that this new weak version of hyperon–hyperon interaction favours the occurrence of kaons in comparison with the strong one.
53643146
Constraints on unparticle interactions from particle and antiparticle oscillations
AbstractUnparticles have dramatic effects on particle and antiparticle oscillations in meson–antimeson and muonium–antimuonium systems. Unlike the usual tree-level contributions to meson oscillations from heavy-particle exchange, which results in a small Γ12, the unparticle may have sizeable contributions to both M12 and Γ12 due to the fractional dimension 
$d_{\mathcal{U}}$ 
of the unparticle. If the unparticle effect dominates the contributions (which may happen in D0–
$\bar{D}^{0}$ 
mixing) to the meson mixing parameters x and y, we find that 
$x/y=\cot(\pi d_{\mathcal{U}})$
. The mass difference Δm in meson mixing can provide interesting constraints on the unparticle interactions. The unparticle interaction can significantly enhance the CP asymmetry in meson mixing, which can be tested in more accurate experiments in the future. Interesting constraints on unparticle and particle interactions can also be obtained using muonion and antimuonion oscillation data.
10151399
Test of CPT symmetry in cascade decays
Abstract. Cascade mixing provides an place for elegant study of $B^0$–$\bar{B^0}$ 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 $\theta$ and $\phi$. A procedure to extract the parameters $\theta$ and $\phi$ is suggested. The feasibility of exploring CPT violation and determining $\theta$ and $\phi$ in the future B-factories and LHC-B is discussed.
14637708
Factorization and polarization in two charmed-meson B decays
We provide a comprehensive test of factorization in the heavy–heavy B decays motivated by the recent experimental data from the BELLE and BABAR collaborations. The penguin effects are not negligible in the B decays with two pseudoscalar mesons. The direct CP asymmetries are found to be a few percent. We give estimates on the weak annihilation contributions by analogy to the observed annihilation-dominated processes. The Nc insensitivity of branching ratios indicates that the soft final state interactions are not dominant. We also study the polarizations in B→D*D(s)* decays. The power law shows that the transverse perpendicular polarization fraction is small. The effects of the heavy quark symmetry breaking caused by the perturbative QCD and power corrections on the transverse polarization are also investigated.