118270514
Covariant lagrangian formulation of interacting heterotic strings
A manifestly Lorentz-covarariant lagrangian formulation of the Neveu-Schwarz-Ramond heterotic string interacting with external fields is presented. The action is derived from the action for fully 26-dimensional semi-superstring by a simple ansatz. The internal space compactification occurs automatically from the action. The twist factors associated with the Kac-Moody algebra are involved in the theory without introducing them by hands.
123479897
Exact Solutions to Mean-Field Equations in Lattice Gauge Theories
16459641
Interaction between Noncommutative Open Strings and Closed-String Tachyons
We construct a vertex operator that describes the emission of a ground-state tachyon of a closedstring out of a noncommutative open string. Such a vertex operator is shown to exist only when the momentum of the closed-string tachyon is subject to some constraints coming from the background B field. When the non-zero background B fieldis lying only on a D-brane, and both ends of the open string are on the D-brane, the closed-string tachyon is emittedfrom the open string in an orthogonal d irection to the D-brane. The vertex operator has a multiplicative coupling constant g(σ) which depends on σ as g(σ) = sin 2 σ in 0 ≤ σ ≤ π. This behavior is the same as in the ordinary B = 0 case.
120052040
Axially Symmetric Solutions for Field Strengths in Non-Abelian Gauge Theories
We find axially symmetric cla"ical solutions to static equations for SU (2) gauge field strengths. These equations can also be derived from the hydrodynamic Lagrangian of Seo and Okawa, so it is possible to interpret our solution hydrodynamically. In these solutions there appears a circulation flow of fluid around the z-axis owing to the vorticity source. In addition there are two flows along the z-axis, one in the positive z-direction for y>O(x O).
123170513
Color-Magnetic Permeability of QCD Vacuum
In a preYious papern we have shown that the true ground-state yacuum of QCD (quantum chromodynamics) has lower energy than the "perturbative vacuum." The MIT bag constant may be given by the energy density difference between the perturbative vacuum and the true ground-state vacuum of QCD, because in the MIT bag model the perturbative vacuum is used inside the bag, while on the outside we have for the fields an impenetrable vacuum. In the present paper we calculate the color-magnetic permeability lie of the QCD true vacuum and show this value to be 1/2 within the quark-one-loop approximation. A gl uon-loop contribution to the QCD vacuum is shown to be neglected when the number of quark flavor is large. If lie= 0, the vacuum is the perfect diamagnet so that quarks and gluons may be confined inside Abrikosov flux lines by the Meissner effect. However, m view of our result fie= 1/2 this confinement is still imperfect at this stage. We begin with a review of our previous work. We adopt the following expression of the SU (2) background gauge field:
121289650
Schwarzian Connections in the Krichever-Novikov Algebra
In the local operator approach to higher-genus Riemann surface we point out an importance of
15509349
Performance of hpge detectors in high magnetic fields
Abstract A new generation of high-resolution hypernuclear γ -spectroscopy experiments with high-purity germanium detectors (HPGe) are presently designed at the FINUDA spectrometer at DA Φ NE, the Frascati φ -factory, and at P ¯ ANDA , the p ¯ p hadron spectrometer at the future FAIR facility. Both, the FINUDA and P ¯ ANDA  spectrometers are built around the target region covering a large solid angle. To maximise the detection efficiency the HPGe detectors have to be located near the target, and therefore they have to be operated in strong magnetic fields ( B ≈ 1 T ). The performance of HPGe detectors in such an environment has not been well investigated so far. In the present work VEGA and EUROBALL Cluster HPGe detectors were tested in the field provided by the ALADiN magnet at GSI. No significant degradation of the energy resolution was found, and a change in the rise time distribution of the pulses from preamplifiers was observed. A correlation between rise time and pulse height was observed and is used to correct the measured energy, recovering the energy resolution almost completely. Moreover, no problems in the electronics due to the magnetic field were observed.