122357291
UNPARTICLE PHYSICS AND NEUTRAL MESON MIXING
The concept of exact and broken scale invariance is discussed. We give a brief introduction to unparticle physics. The neutral meson mixing can be caused by exchange of unparticle at the tree level. The constraints on interaction between unparticle and SM quarks are discussed.
15594064
The Factorization in exclusive B decays: A Critical look
I review the theoretical ideas and concepts along the line of factorization in the exclusive B decays. In order to understand the naive factorization, the effective field theories and the perturbative method of QCD are introduced and developed. We focus our discussions on the large energy effective theory, the QCD factorization approach and the soft-collinear effective theory.
119155459
Neutrino decay as a possible interpretation of the MiniBooNE observation with unparticle scenario
In a new measurement on neutrino oscillations, νμ→νe, the MiniBooNE Collaboration observes an excess of electron-like events at low energy and the phenomenon may demand an explanation that obviously is beyond the oscillation picture. We propose that the heavier neutrino, ν2, decaying into a lighter one, ν1, via the transition process νμ→νe+X, where X denotes any light products, could be a natural mechanism. The theoretical model we employ here is the unparticle scenario established by Georgi. We have studied two particular modes $\nu_{\mu}\to\nu_{e}+\mathcal{U}$ and νμ→νe+ν̄e+νe. Unfortunately, the number coming out of the computation is too small to explain the observation. Moreover, our results are consistent with the cosmology constraint on the neutrino life time and the theoretical estimation made by other groups; therefore, we can conclude that even though neutrino decay seems plausible in this case, it indeed cannot be the source of the peak at lower energy observed by the MiniBooNE Collaboration and there should be other mechanisms responsible for the phenomenon.
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.
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.
14014748
The reliability of pQCD approach in pion electromagnetic form factor
The pion electromagnetic form factor with leading and next-to-leading twist corrections are studied in the framework of pQCD approach. We find that, at small momentum transfer regions, Sudakov effects cannot provide a strong enough suppression of the non-perturbative contributions coming from large transverse separations, but at large momentum transfer region, non-perturbative contributions can be effectively suppressed. So pQCD approach can be applied at large momentum transfer region. At the energy region where experiment can access so far, i.e. Q < 4GeV, pQCD prediction can not be precise because there may be a quite large part of contributions coming from non-perturbative region. The calculation of power corrections may not be performed systematically in pQCD framework.
119572213
Colour Dipole Picture for Deep Inelastic Scattering in the Collinear Factorization Scheme
The colour dipole picture for deep inelastic scattering processes is generalized in the collinear factorization scheme. We show that a duality between the colour dipole picture and scattering picture is lost in higher twist amplitudes.
124725065
Gluon Cluster in Nuclei and EMC Effect
The gluebond and its role in the EMC offect are proposed in this paper. The discrepancy between electro and muon-production data can be ascribed to the QCD evolution of the gluebond in nuclei. The enhancement of the gluon distribution at small , observed in muon-production experiment, can be also explained by using the gluebond model.
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.
123800661
Probing the nuclear symmetry energy using single and double pi(-)/pi(+) ratios from mirror reaction systems
123160166
Nuclear Shadowing in Very Small Bjorken Variable Region
We show that partonic shadowing model can be used to describe the nuclear shadowing phenomena of Q2 > 1 Gev2. The shadowing saturation observed in E665 experiment in very small Bjorken variable region is originated from the interaction between the component of vector meson in the probe γ* and the nuclear target while Q2 < 0.1 GeV2.