Light-Cone Gauge String Field Theory in Noncritical Dimensions

We study light-cone gauge string field theory in noncritical space-time dimensions. Such a theory corresponds to a string theory in a Lorentz noninvariant background. We identify the worldsheet theory for the longitudinal coordinate variables $X^\pm$ and study its properties. It is a CFT with the right value of Virasoro central charge, using which we propose a BRST invariant formulation of the worldsheet theory.Comment: 27 pages, 2 figure

Light-cone Gauge NSR Strings in Noncritical Dimensions

Light-cone gauge NSR string theory in noncritical dimensions should correspond to a string theory with a nonstandard longitudinal part. Supersymmetrizing the bosonic case [arXiv:0909.4675], we formulate a superconformal worldsheet theory for the longitudinal variables X^{\pm}, \psi^{\pm}. We show that with the transverse variables and the ghosts combined, it is possible to construct a nilpotent BRST charge.Comment: 22 pages, 1 figur

Light-cone Gauge Superstring Field Theory and Dimensional Regularization II

We propose a dimensional regularization scheme to deal with the divergences caused by colliding supercurrents inserted at the interaction points, in the light-cone gauge NSR superstring field theory. We formulate the theory in $d$ dimensions and define the amplitudes as analytic functions of $d$. With an appropriately chosen three-string interaction term and large negative $d$, the tree level amplitudes for the (NS,NS) closed strings can be recast into a BRST invariant form, using the superconformal field theory proposed in Ref.[arXiv:0911.3704]. We show that in the limit $d \to 10$ they coincide with the results of the first quantized theory. Therefore we obtain the desired results without adding any contact interaction terms to the action.Comment: 23 pages; v2: minor modifications; v3: revised argument in section 3, added appendix C, results unchanged; v4: added clarifications, two figures and a footnote; v5: minor modification

Twist-3 Effects in Polarized Photon Structure

The polarized photon structure is described by two spin structure functions $g_1^\gamma$ and $g_2^\gamma$ which can be studied in the future polarized ep or e$^+$e$^-$ colliders. Here we investigate the QCD twist-3 effects in $g_2^\gamma$ to the leading order in QCD.Comment: 4 pages, LaTeX2e, 2 eps figures, ws-ijmpa.cls file included, Talk given at the 3rd Circum-Pan-Pacific Symposium on High Energy Spin Physics, Beijing, October 8-13, 2001, to appear in the Proceeding

D-brane States and Disk Amplitudes in OSp Invariant Closed String Field Theory

We construct solitonic states in the OSp invariant string field theory, which are BRST invariant in the leading order of regularization parameter $\epsilon$. We calculate the disk amplitudes using these solitonic states and show that they describe D-branes and ghost D-branes.Comment: 37 pages, 8 figure

Spacetime Fermions in Light-cone Gauge Superstring Field Theory and Dimensional Regularization

We consider the dimensional regularization of the light-cone gauge type II superstring field theories in the NSR formalism. In the previous work, we have calculated the tree-level amplitudes with external lines in the (NS,NS) sector using the regularization and shown that the desired results are obtained without introducing contact term interactions. In this work, we study the tree-level amplitudes with external lines in the Ramond sector. In order to deal with them, we propose a worldsheet theory to be used instead of that for the naive dimensional regularization. With the worldsheet theory, we regularize and define the tree-level amplitudes by analytic continuation. We show that the results coincide with those of the first quantized formulation.Comment: 28 pages, 5 figures; v2: more details of our manipulations in subsection 3.2 added, figures and references added; v3: clarifications adde

Some geochemical considerations in the petrogenesis of Madagali granitoids, northeastern Nigeria

Major and trace element geochemical data on granitoids of Madagali area of northeastern Nigeria show a series that ranges from K-calc-alkaline, through granodiorite-monzogranite to granite. They are characterized as mildly peraluminous to metaluminous and I-type based on alumina saturation index (ASI). Trace element contents preclude the possibility of entire mantle origin and indicate significant crustal involvement in the evolution of the granitoids. The enrichment in LREE ( La, Ce and, Nd), depletion in HREE (Ho, Er, Yb and Lu) and a pronounced negative Eu anomaly with (La/Yb)N suggest that the granitoids must have evolved by partial fractionation or partial melting of the pre-existing crust in which plagioclase feldspar was retained. Furthermore, the enrichments in some large-ionlithophile elements (LILE) such as Rb, Ba, Th and K and depletion in some high field strength (HFS) elements such asNb, P, and Ti as well as some transitional elements Cr and Ni are supportive of crustal involvement in their genesi