共查询到20条相似文献,搜索用时 15 毫秒
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Type I superstring theory was previously shown to be anomaly-free if the gauge group is SO(32). Here it is demonstrated that the same group is also singled out by the requirement that infinities can be canceled by combining diagrams. 相似文献
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Y. Nagahama 《Zeitschrift fur Physik C Particles and Fields》1988,39(1):47-56
We explicitly calculate the hexagon and heptagon (covariant) gauge anomaly including the precise numerical coefficients in type-I open superstring. The calculation is performed by using the Pauli-Villars regularization on the basis of the stringy Ward identity, which is an assumption weaker than the cancelled propagator argument. We show that the anomalies in the effective theory are realized as the zero slope limit (α′→0) of the string anomalies in a very non-trivial way in the present calculational scheme. This non-trivial realization in higher point (n≧8) anomalies is also discussed. 相似文献
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《Physics letters. [Part B]》1986,178(1):15-20
The phenomenology of superstring theories in which the gauge symmetry after compactification is SO(10) × E′8, instead of E6 × E′8, is discussed. In particular, the generation of an intermediate scale, the radiative breaking of electroweak symmetry, and the supersymmetric particle spectrum are investigated. 相似文献
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The pure spinor formalism for the superstring has recently been used to compute massless four-point two-loop amplitudes in a manifestly super-Poincaré covariant manner. In this Letter, we show that when all four external states are Neveu-Schwarz states, the two-loop amplitude coincides with the Ramond-Neveu-Schwarz result. 相似文献
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《Physics letters. [Part B]》1987,186(1):52-56
We discuss the general problem of divergences and the particularly important “tadpole” configuration for multiloop amplitudes in the closed superstring - or heterotic string - covariant theory, with any number of external legs. We show that, due to a factor coming from the supermoduli, the tachyon divergence in the tadpole is cancelled in each spin structure contribution separately. 相似文献
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Motivated by recent experiments with Bechgaard salts, we investigate the competition between antiferromagnetism and triplet superconductivity in quasi-one-dimensional electron systems. We unify the two orders in an SO(4) symmetric framework, demonstrating the existence of such symmetry in one-dimensional Luttinger liquids. SO(4) symmetry strongly constrains the phase diagram, leading to coexistence regions of antiferromagnetic, superconducting, and normal phases, as observed in (TMTSF)(2)PF(6). We predict a sharp neutron scattering resonance in superconducting samples. 相似文献
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《Physics letters. [Part B]》1987,194(4):506-510
Earlier, we have established that, for a constrained system with a first class bosonic constraint algebra, the standard BRST invariance generalizes to an OSP(1, 1|2) symmetry, with four nilpotent and anticommuting BRST-type operators. Here we generalize this to arbitrary constrained systems with a graded first class constraint algebra. Our approach is based on the Fradkin- Vilkovisky formalism and uses a relation between abelian and nonabelian constraint algebras. Subsidiary constraints and generalized structure constants play an important role in the construction. As an application, we construct the OSP(1, 1|2) generators for superstrings. Here the subsidiary constraints are identified with physically relevant operators used in the unitarity proof. 相似文献
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A realistic supersymmetric SO(10) grand unified theory is explicitly constructed. The neutrino masses turn out to be 10?5 eV or less. It is also found that the proton life time can be longer than 1031 yr. 相似文献
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We perform a thorough study of 3+1-dimensional SO(3) LGT for fixed-twist background. We concentrate in particular on the physically
significant trivial and 1-twist sectors. Introducing a ℤ2 monopole chemical potential the 1st order bulk transition is moved down in the strong coupling region and weakened to 2nd
order in the 4-dimensional Ising model universality class. In this extended phase diagram we gain access to a confined phase
in every fixed-twist sector of the theory. The Pisa disorder operator is employed together with the Polyakov loop to study
the confinement–deconfinement transition in each sector. Due to the specific properties of both operators, most results can
be used to gain insight in the ergodic theory, where all twist sectors should be summed upon. An explicit mapping of each
fixed-twist theory to effective positive plaquette models with fixed-twisted boundary conditions is applied to better establish
their properties in the different phases. 相似文献
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《Physics letters. [Part B]》1988,212(3):292-298
It is shown that the BRST-cohomology in the enlarged bosonized formulation of the superstring field theory is trivial, and the “homotopy operation” that implements this traviality is given. As a result of truncating the enlarged representation to the irreducible one, the picture changing operation emerges in a quite natural way as a residual effect of the underlying structure. 相似文献
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J. Paukonis 《Fortschritte der Physik》2005,53(9):1011-1029
In this paper we perform the calculation of the gravitational scattering amplitude for 4 massless scalars in quantum field theory and Type II superstring theory. We show that the results agree, providing an example of how gravity is incorporated in the superstring theory. During the calculation we quantize gravitational action to derive graviton propagator and interaction vertex with massless scalar. We also calculate general 3‐point and 4‐point scattering amplitudes in SST for open and closed massless strings in NS sector. 相似文献
20.
Rainer Dick 《International Journal of Theoretical Physics》1997,36(9):2005-2012
I examine the potential of a pointlike particle carrying SU (N
c) charge in a gauge theory with a dilaton. The potential depends on boundary conditions imposed on the dilaton: For a dilaton
that vanishes at infinity the resulting potential is a regulatized Coulomb potential of the form (r+r
ϕ)−1, withr
ϕ, inversely proportional to the decay constant of the dilaton. Another natural constraint on the dialaton ϕ is independence
of (1/g
2) exp(ϕ/fϕ) from the gauge couplingg. This requirement yields a confining potential proportional tor. 相似文献