14293872
The mass formula for a fundamental string as a BPS solution of a D-brane's worldvolume
Abstract We propose a (generalized) “mass formula” for a fundamental string described as a BPS solution of a D-brane's worldvolume. The mass formula is obtained by using the Hamiltonian density on the worldvolume, based on transformation properties required for it. Its validity is confirmed by investigating the cases of point charge solutions of D-branes in a D-8-brane (i.e. curved) background, where the mass of each of the corresponding strings is proportional to the geodesic distance from the D-brane to the point parametrized by the (regularized) value of a transverse scalar field. It is also shown that the mass of the string agrees with the energy defined on the D-brane's worldvolume only in the flat background limit, but the agreement does not always hold when the background is curved.
9070559
Various Supersymmetric Brane Configurations from Superalgebras in Many Types of M-Brane Backgrounds
We derive superalgebras in many types of supersymmetric M-brane backgrounds. The backgrounds examined here include the cases of the M-wave and the M-Kaluza-Klein monopole. On the basis of the obtained algebras, we deduce all the supersymmetric nonorthogonal intersections of the M-Kaluza-Klein monopole and the M-5-brane at angles, most of which were previously unexamined. In addition, we present a new worldvolume soliton on the M-5-brane in the M-5-brane background which is interpreted as a certain intersection of three M-5-branes. The soliton has 1/8 supersymmetry, which can easily be confirmed by using the superalgebra. tsato@icrr.u-tokyo.ac.jp
17296162
Superalgebras in many types of M-brane backgrounds and various supersymmetric brane configurations
We derive superalgebras in many types of supersymmetric M-brane backgrounds. The backgrounds examined here include the cases of the M-wave and the M-Kaluza-Klein monopole. On the basis of the algebras obtained, we deduce all the supersymmetric non-orthogonal intersections of the M-Kaluza-Klein monopole and the M5-brane at angles. In addition, we present a 14 supersymmetric world-volume 3-brane soliton on the M5-brane in the M5-brane background as an extended solution of the 3-brane solitons of the M5-brane by Howe, Lambert and West. This soliton can be interpreted as a certain intersection of three M5-branes.
14541880
D-brane dynamics and creations of open and closed strings after recombination
Abstract A quantum-mechanical technique is used within the framework of U(2) super-Yang–Mills theory to investigate what happens in the process after recombination of two D p -branes at one angle. Two types of initial conditions are considered, one of which with p =4 is a candidate of inflation mechanism. It is observed that the branes' shapes come to have three extremes due to localization of tachyon condensation. Furthermore, open string pairs connecting the decaying D-branes are shown to be created; most part of the released energy is used to create them. It also strongly suggests that creation of closed strings happens afterward. Closed strings as gravitational radiation from the D-branes are also shown to be created. A few speculations are also given on implications of the above phenomena for an inflation model.
14027850
THE SPACETIME SUPERALGEBRAS FROM M-BRANES IN M-BRANE BACKGROUNDS
Abstract We derive the spacetime superalgebras explicitly from “test” M-brane actions in M-brane backgrounds to the lowest order in θ via canonical formalism, and discuss various BPS saturated configurations on the basis of their central charges which depend on the harmonic functions determined by the backgrounds. All the 1/4 supersymmetric intersections of two M-branes obtained previously are deduced from the requirement of the test branes to be so “gauge fixed” in the brane backgrounds as to preserve 1/4 supersymmetry. Furthermore, some of 1/2-supersymmetric bound states of two M-branes are deduced from the behavior of the harmonic functions in the limits of vanishing distances of the two branes. The possibilities of some triple intersections preserving 1/4 supersymmetry are also discussed.
9039443
A QUANTUM ANALYSIS ON RECOMBINATION OF D-BRANES AND ITS IMPLICATIONS FOR AN INFLATION MODEL
A quantum-mechanical technique is used within the framework of U(2) super-Yang-Mills theory to investigate processes after recombination of two D-p-branes at one angle. Two types of initial conditions are considered, one of which with $p=4$ is a candidate of inflation mechanism. It is shown that the branes' shapes come to have three extremes due to localization of tachyon condensation. ``Pair-creations'' of open stings connecting the recombined branes is also observed. The appearance of closed strings is also discussed; the decaying branes are shown to radiate non-vanishing gravitational wave, which may be interpreted as evidence of closed string appearance. A few speculations are also given on implications of the above phenomena for an inflation model.
118668452
Neutrino-induced forward meson-production reactions in nucleon resonance region
As a first step toward developing a reaction model that enables a comprehensive description of neutrino-nucleon reactions in the nucleon resonance region, we have applied for the first time a dynamical coupled-channels model, which successfully describes \pi N, \gamma N --> \pi N, \eta N, \pi \pi N, K\Lambda, K\Sigma reactions up to W = 2 GeV, to predict the neutrino-induced meson-production reactions with \Delta S = 0 at the forward angle limit. This has been achieved by relating the divergence of the axial-current matrix elements at Q^2 = 0 to the \pi N --> X reaction amplitudes through the PCAC hypothesis. We present the contributions from each of the \pi N, \eta N, \pi \pi N, K\Lambda, K\Sigma channels to the F_2 structure function at Q^2 --> 0 limit up to W = 2 GeV.