Vertex Operators in IIB Matrix Model

The vertex operators for the supergravity multiplet can be constructed through the Wilson lines in IIB matrix model. We investigate the structure of the vertex operators and the symmetry of their correlation functions. For this purpose, we perturb the theory by the Wilson lines dual to the supergravity multiplet. The structure of the Wilson lines can be determined by requiring $\cal{N}$=2 SUSY under the low energy approximation. We argue that the generating functional of the correlators is invariant under local SUSY transformations of IIB supergravity.Comment: 21 pages; references adde

Quasiparticle picture of quarks near chiral transition at finite temperature

We investigate, using a chiral effective model, the quark spectrum in the critical region of the chiral transition focusing on the effect of the possible mesonic excitations in the quark-gluon plasma phase. We find that there appears a novel three-peak structure in the quark spectra. We elucidate the mechanism of the appearance of the multi-peak structure with the help of a Yukawa model with an elementary boson.Comment: 4 pages, 5 eps figures, to appear in the proceedings of International Conference on Strong & Electroweak Matter 2006, Brookhaven National Laboratory, USA, May 10-13, 200

Precursor of Color Superconductivity

We investigate possible precursory phenomena of color superconductivity at finite temperature $T$ with an effective theory of QCD. It is found that the fluctuation of the diquark pair field exists with a prominent strength even well above the critical temperature $T_c$. We show that such a fluctuaiton forms a collective mode, the corresponding pole of which approaches the origin as $T$ is lowered to $T_c$ in the complex energy plane. We discuss the possible relevance of the precursor to the observables to be detected in heavy-ion collisions.Comment: 4 pages, 5 figures, Talk presented at the XVIth International Conference on Particles and Nuclei (PANIC02), Osaka, Japan, Sep.30 - Oct.4, 2002, Uses espcrc1.st

String Field Theory from IIB Matrix Model

We derive Schwinger-Dyson equations for the Wilson loops of a type IIB matrix model. Superstring coordinates are introduced through the construction of the loop space. We show that the continuum limit of the loop equation reproduces the light-cone superstring field theory of type IIB superstring in the large-N limit. We find that the interacting string theory can be obtained in the double scaling limit as it is expected.Comment: 21 pages, Latex, 1 figur

Chiral and Color-superconducting Phase Transitions with Vector Interaction in a Simple Model (Addenda)

In the preceding paper(Prog.Theor.Phys.108(2002)929 or hep-ph/0207255), we have shown that the critical line of the first order chiral transition of QCD can have two endpoints. In this addendum, we elucidate the mechanism to realize the two-endpoint structure in the QCD phase diagram and argue the robustness for the appearance of such an interesting phase structure

Setting Children Free: Children’s Independent Movement in the Local Environment

Parental concerns about children’s safety and security are restricting children’s independent exploration of the local environment. Children are being denied important opportunities to exercise, to acquire decision-making skills, such as crossing the road safely, and to develop social skills through interaction with their peers. This paper presents findings from the project CAPABLE (Children’s Activities, Perceptions And Behaviour in the Local Environment) being carried out at University College London. Based on findings from fieldwork carried out with children aged 8-11 in Cheshunt, Hertfordshire, the paper shows the effect of factors such as the number of adults at home, having an older sibling, having a car or garden at home and living near to a park on the propensity to be allowed out alone. Then it considers how being allowed out alone affects the amount of time children spend outdoors, playing with friends and watching television. The paper then uses data from children who have been fitted with physical activity monitors and GPS (Global Positioning Satellite) monitors and asked to keep diaries, to show how children’s travel behaviour differs when they are with adults from when they are not