We consider the annihilation process of an electron-positron pair into a pair of heavier fermions when the initial electron and positron beams are polarized. By calculating the polarization of the final-state particles, we discuss in detail the effect due to the produced particle masses in the T-charm energy region at BEPC/BES, and also compare the effect with that at the B-factory. Such a study is useful for the design of possible polarization investigation at the BEPC/BES facility and the B-factory.
We report that a general principle of physical independence of mathematical background manifolds brings a replacement of common derivative operators by co-derivative ones. Then we obtain a new Lagrangian for the ordinary minimal standard model with supplementary terms containing the Lorentz invariance violation information measured by a new matrix, denoted as the Lorentz invariance violation matrix. We thus provide a new fundamental theory to study Lorentz invariance violation effects consistently and systematically.
We study the entropic force effects on black holes and photons. It is found that application of an entropic analysis restricts the radial change △R of a black hole of radius RH, due to a test particle of a Schwarzschild radius Rn moving towards the black hole by △x near a black body surface, to be given by a relation RH△R = Rh△x/2, or △ R/λM = △x /2λm. We suggest a new rule regarding entropy changes in different dimensions, △S = 2πkD △l/λ, which unifies Verlinde＇s conjecture and the black hole entropy formula. We also propose the extension of the entropic force idea to massless particles such as photons. It is realized that there is an entropic force on a photon of energy Eγ with F = GM（Eγ/c^2）/R^2, and therefore the photon has an effective gravitational mass mγ= Eγ/c^2.
The newly proposed entropic gravity suggests gravity as an emergent force rather than a fundamental one. In this approach,the Newtonian constant G does not play a fundamental role any more, and a new fundamental constant is required to replace itsposition. This request also arises from some philosophical considerations to contemplate the physical foundations for the unificationof theories. We here consider the suggestion to derive G from more fundamental quantities in the presence of a new fundamentallength scale l, which is suspected to originate from the structure of quantum space-time, and can be measured directly from Lorentz-violating observations. Our results are relevant to the fundamental understanding of physics, and more practically, of natural units,as well as explanations of experimental constraints in searching for Lorentz violation.
A new and simple statistical approach is performed to calculate the parton distribution functions （PDFs） of the nucleon in terms of light-front kinematic variables.Analytic expressions of x-dependent PDFs are obtained in the whole x region.And thereafter,we treat the temperature T as a parameter of the atomic number A to explain the nuclear EMC effect in the region x ∈ [0.2,0.7].We give the predictions of PDF ratios,and they are very different from those by other models,thus experiments aiming at measuring PDF ratios are suggested to provide a discrimination of different models.
