[en] We discuss how to construct theta vacua in the light-front field theories using the 1+1 dimensional Abelian Higgs model as an example. Unlike the non-gauged scalar field, zero modes of the Higgs field are in general dynamical as well as the gauge-field zero mode. While symmetry breaking is discussed in semi-classical treatment of the zero modes, the theta vacua are introduced in the quantum level by use of the large gauge symmetry

[en] A method of describing the dynamical chiral symmetry breaking on the light front is exemplified in a chiral symmetric Yukawa model which is closely related to the NJL model. Emphasis is put on the importance of longitudinal zero modes of fermion bilinears

[en] Geometric scaling is a novel phenomenon observed in deep inelastic scattering (DIS) at small χ: the total γ^*p cross section depends upon the two variables Q² and χ only via their combination ζ ≡ Q²R₀²(χ), with R₀²(χ) ∞ χ^λ. We show that this scaling can be naturally understood as a manifestation of gluon saturation based on the effective theory for high density matter of saturated gluons, namely, the Color Glass Condensate (CGC)

[en] We apply the light-front quantization to the Nambu-Jona-Lasinio model with the vector interaction, and compute vector meson's mass and light-cone wavefunction in the large N limit. Following the same procedure as in the previous analyses for scalar and pseudo-scalar mesons, we derive the bound-state equations of a qq-bar system in the vector channel. We include the lowest order effects of the vector interaction. The resulting transverse and longitudinal components of the bound-state equation look different from each other. But eventually after imposing an appropriate cutoff, one finds these two are identical, giving the same mass and the same (spin-independent) light-cone wavefunction. Mass of the vector meson decreases as one increases the strength of the vector interaction

[en] We show that the HERA data for the inclusive structure function F₂(x,Q²) for x≤10^-2 and 0.045≤Q²≤45 GeV² can be well described within the color dipole picture, with a simple analytic expression for the dipole-proton scattering amplitude, which is an approximate solution to the non-linear evolution equations in QCD. For dipole sizes less than the inverse saturation momentum 1/Q_s(x), the scattering amplitude is the solution to the BFKL equation in the vicinity of the saturation line. It exhibits geometric scaling and scaling violations by the diffusion term. For dipole sizes larger than 1/Q_s(x), the scattering amplitude saturates to one. The fit involves three parameters: the proton radius R, the value x₀ of x at which the saturation scale Q_s equals 1 GeV, and the logarithmic derivative of the saturation momentum λ. The value of λ extracted from the fit turns out to be consistent with a recent calculation using the next-to-leading order BFKL formalism

[en] It has been strongly suggested by the results of the heavy ion collision experiments at RHIC that the 'state of high energy density' possibly comes to the 'thermal equilibrium (Quark Gluon Plasma, QGP') in very short time of 1 fm/c. In this paper, the conceptual aspect in the thermal equilibration of the heavy ion collisions is explained including the physics related to this phenomenon, and some theoretical approaches for this problem are introduced. The process is divided into the following five periods. (1) Before the collision: the state is described by Color Glass Condensate (CGC), which is the initial condition of the event. (2) During the collision: the thickness of the nuclei corresponds to the passing time of the nuclei each other, consequently the instant of collision has non zero time width but is about 0.1 fm/c at RHIC. (3) Glasma period: the initial CGC in still affecting at the beginning but this period is characterized by the strong gluon field. The gluon distribution becomes anisotropic due to expansion. Duration is about 0.2 fm/c at RHIC assuming Q_s -1GeV. (4) Period toward isotropic distribution: the system becomes isotropic due to the instability of gluon field induced by the interaction between anisotropic hard gluon particles and soft gluon field. Estimated time scale is 0.7 fm/c for RHIC (not the time of realization). (5) Thermally equilibrating period: the system gradually transfers to thermal equilibrium by the inter-particle interaction, the mechanism of which is yet unknown. (S. Funahashi)

[en] One- and two-dimensional nuclear Overhauser effect experiments demonstrate that a single hydrogen bond between a T imino proton and purine N3 is sufficient to hold the base pair dPu-dT in d(CGPuAATTTCG) by a Watson-Crick fashion rather than a Hoogsteen type. In addition, the dPu-dT base pair is well stacked with neighboring base pairs. The spin-lattice relaxation measurements at 30 and 35⁰C of two decamers, d(CGPuAATTTCG) and d(CGAAATTTCG), reveal that the elimination of two single hydrogen bonds of dA-dT base pairs (due to the substitution of adenine for purine) in the sequence results in an increase in the overall imino proton exchange rate from 7 to 36 s^-1 at the site of mismatch

[en] This talk is a brief overview of the light-front quantization as a new non-perturbative method and its application to hadron physics. Emphasis is put on the recent progress in describing the 'vacuum physics' on the light front. (author)

[en] Lead molybdate (PbMoO₄) is found to be an efficient scintillator when cooled down to liquid nitrogen temperature. The scintillation light of PbMoO₄ excited by γ-rays amounts to as much as 16% of that of NaI(Tl) in the wavelength range between 180 nm and 650 nm and the decay time is as long as 11 μs if it is cooled below 100 K. Since ¹⁰⁰Mo, whose natural abundance is 9,6%, is a double β decay nuclide, the PbMoO₄ can be useful for the double β decay experiment. (orig.)

[en] We discuss the 'odderon' exchange at high energy within the framework of the Color Glass Condensate (CGC). The theoretical framework for the CGC is intended to describe hadronic scatterings at very high energies. We explain its general strategies by using the scattering of a simple projectile in a reference frame where most of the total momentum of the scattering is carried by the target and we apply these strategies to the odderon exchange. These strategies imply: first to treat the target as a CGC which is a dense gluonic state on 2 dimensional transverse planes, then to determine the scattering operator which is associated with the specific scattering process, the eikonal approximation is used, and finally we have to compute the evolution equation for the relevant operator within the framework of JIMWLK equation. The description of C-odd 'odderon' exchange at high energies can be done by adding the information of the C parities to the incoming and outgoing states. We discuss 2 simple projectiles: a color dipole and a 3-quark state. (A.C.)