[en] Recent released WMAP data show a low value of quadrupole in the CMB temperature fluctuations, which confirms the early observations by COBE. In this Letter we consider a model of two inflatons with different masses, V(phi₁,phi₂)=((1)/(2))m₁²phi₁²+((1)/(2))m₂²phi₂², m₁>m₂ and study its effects on CMB of suppressing the primordial power spectrum P(k) at small k. Inflation is driven in this model firstly by the heavier inflaton phi₁, then the lighter field phi₂. But there is no interruption in between. We numerically calculate the scalar and tensor power spectra with mode by mode integrations, then fit the model to WMAP temperature correlations TT and the TE temperature-polarization spectra. Our results show that with m₁∼10¹⁴ GeV and m₂∼10¹³ GeV, this model solves the problems of flatness, etc. and the CMB quadrupole predicted can be much lower than the standard power-law ΛCDM model

[en] k-Essence is a possible candidate for dark energy of the Universe. In this Letter we consider couplings of k-essence to the matter fields of the standard electroweak theory and study the effects of the cosmological CPT violation induced by the CPT violating ether during the evolution of the k-essence scalar field on the laboratory experiments and baryogenesis. Our results show that the matter and antimatter asymmetry can be naturally explained via leptogenesis without conflicting with the experimental limits on CPT violation test. The mechanism for baryogenesis proposed in this Letter provides a unified picture for dark energy and baryon matter of our Universe and allows an almost degenerate neutrino mass pattern with a predicted rate on the neutrinoless double beta decays accessible to the experimental sensitivity in the near future

[en] After neutralinos cease annihilating in the early Universe, they may still scatter elastically from other particles in the primordial plasma. At some point in time, however, they will eventually stop scattering. We calculate the cross sections for neutralino elastic scattering from standard-model particles to determine the time at which this kinetic decoupling occurs. We show that kinetic decoupling occurs above a temperature T∼MeV. Thereafter, neutralinos act as collisionless cold dark matter

[en] An improved version of the grand unification composite model propose earlier is suggested. Under the hypothesis of partly broken global chiral symmetry, we give the four family of Fermions at low energies to realize unification of four family of Fermions. Neutrino may acquire naturally the Dirac mass. Proton lifetime and weak neutral current at low energy are consistent with experimental results

[en] In this Letter, we consider a model of tachyon with a non-minimal coupling to gravity and study its cosmological effects. Regarding inflation, we show that only for a specific coupling of tachyon to gravity this model satisfies observations and solves various problems which exist in the single and multi tachyon inflation models. But noting in the string theory the coupling coefficient of tachyon to gravity is of order g_s, which in general is very small, we can hardly expect that the non-minimally coupling of tachyon to gravity could provide a reasonable tachyon inflation scenario. Our work may be a meaningful try for the cosmological effect of tachyon non-minimally coupled to gravity

[en] According to WNW condition, a systematic analysis about the restraints from GUT on chiral three-preon model with confining weak interaction is discussed. It shows that the metacolor gauge group may not be SU(N) or SO(M), but may be semisimple group, for example, SU(N) x SO(M) or SU(N) x SU(M). By calculating, the candiats are G_MC = SU(3) x SO(5) and G_U ≥ SU(11), G_MC = SU(3) x SU(2) and G_U ≥ SU(12) under conditions: 10¹⁴GeV ≤ A_U ≤ 10¹⁹ GeV and 300GeV ≤ A_MC ≤ 1TeV

[en] Beijing Spectrometer (BES) at Beijing Electron Positron Collider (BEPC),IHEP has accumulated 2.5 x 10⁷ J/ψ events and plans to increase this number to 10⁸ - 10⁹ in the near future. The author review and summarize the recent studies on the possibilities of probing for new physics at BES. This includes the theoretical works on and experimental attempt performed at BES in searching for flavor changing neutral current, CP violation and lepton flavor violation in the processes of J/ψ decays

[en] A composite model with hypercolor group being semi-simple gauge group is discussed. A SU(4) x SU(4) composite model with confining weak interactions is proposed, which gives three families of light fermions

[en] In this paper I discuss some of the phenomenologies of models of the dark energy interacting with the ordinary matter. After a very brief review about the current constraint on the equation of the state of the dark energy from the SN and a new scenario of dark energy the Quintom, I present models of Quintessential Baryo(Lepto) genesis, Quintessino dark matter and mass varying neutrinos in details. (author)

[en] Unveiling the nature of dark matter and dark energy is one of the main tasks of particle physics and cosmology in the 21st century. We first present an overview of the history and current status of research in cosmology, at the same time emphasizing the new challenges in particle physics. Then we focus on the scientific issues of dark energy, dark matter and anti-matter, and review the recent progress made in these fields. Finally, we discuss the prospects for future research on the experimental probing of dark matter and dark energy in China. (authors)