123479897
Exact Solutions to Mean-Field Equations in Lattice Gauge Theories
120807669
Theory of the Dual-Fermion String
'In the string model of the fermion we consider the physical meaning of the DiracRamond equation and the supergauge conditions for both the free and. the interacting cases, The interaction of the string with external fields is determined in such a way that it is conformally invariant and is compatible with the gauge conditions. Any fermion states have zero norm when the ground-state fermion has zero mass. For this reason we consider a definition of S-matrix elements:' The proof of the absence of ghosts is then reexamined. The 10-dimensional Dirac equation is reduced to the usual 4-dimensional Dirac equation with a mass term. Finally the isospin quantum number is introduced into the string in such a way that all the algebraic relations remain unchanged.
122480764
Supergauge Algebra and Electromagnetic Interaction of the Dual Pion Model. II
We consider the electromagnetic problems of the dual pion model proposed by Neveu and Schwarz. The photon gauge substitution and the supergauge algebra appearing in this model are shown to determine the interaction uniquely. Consequently we find that (i) the electric charge has only two localization points which are at the ends of the string and that (ii) new gauge conditions hold, which are crucial for proving the no-ghost theorem in our t)leory. We also give a proof of the photon-gauge invariance of our system and find (iii) the conserved dual current. Unfortunately we are forced to stay in the on-shell world (i.e., massless photon).
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.
121289650
Schwarzian Connections in the Krichever-Novikov Algebra
In the local operator approach to higher-genus Riemann surface we point out an importance of
121930670
Supergauge Algebra and Interaction between Open and Closed Strings
In the Neveu-Schwarz and Ramond models we construct the vertices which describe the emission of closed-string ground-state particles out of open string states. The modified supergauge algebra associated with the new vertices can be shown to hold in the same form as the usual supergauge algebra in free cases. and is crucial for proving the no-ghost theorem in our system.
122641390
The T=2 mirrors 36Ca and 36S: A test for isospin symmetry of shell gaps at the driplines
The first excited 2 + state of 36 Ca has been identified by its γ -decay, exploiting the two-step fragmentation technique at the FRS-RISING setup at GSI. This is the heaviest Tz =− 2 nucleus in the Segre chart in which a γ -decay of an excited state has been observed. A stable beam of 40 Ca at 420A MeV impinged on a primary 9 Be target. Out of the secondary beam of fragmentation products, 37 Ca was separated by the FRS and struck on a second 9 Be target at the final focus of the FRS. The energy for the 2 + decay of 36 Ca was determined to be 3015(16) keV, which is 276 keV lower than in its T = 2 mirror 36 S. This mirror energy difference (MED) is discussed in the framework of shell model calculations using a 16 O core, the sd shell isospin symmetric interaction USD and experimental single-particle energies from 17 Oa nd 17 F. The results show that the MED within the sd shell provide a sensitive test for the evolution of the N , Z = 14, 16 subshell gaps towards the driplines. Especially the N, Z = 16 gap is determined by Thomas–Ehrman shift in the A = 17, T = 1/2 isospin doublet, while Coulomb effects are found to have marginal influence. © 2007 Elsevier B.V. All rights reserved.