119531985
Callan–Symanzik equations and low-energy theorems with trace anomalies
Based on some new and concise forms of the Callan–Symanzik equations, the low-energy theorems involving trace anomalies a la Novikov–Shifman–Vainshtein–Zakharov, first advanced and proved in Novikov et al (1980 Nucl. Phys. B 165 67, 1981 Nucl. Phys. B 191 301), are proved as immediate consequences. The proof is valid in any consistent effective field theories and these low-energy theorems are hence generalized. Some brief discussions about related topics are given.
119670186
Padé Expansion and the Renormalization of Nucleon–Nucleon Scattering
The importance of imposing physical boundary conditions on the T-matrix to remove the nonperturbative renormalization prescription dependence is stressed and demonstrated in two diagonal channels 1P1 and 1D2, with the help of Pade expansion.
15356070
Can QFT be UV finite as well as effective
A new attempt is demonstrated that QFTs can be UV finite if they are viewed as the low energy effective theories of a fundamental underlying theory (complete and well-defined in all respects) according to the modern standard point of view. This approach is much simpler in principle and in technology comparing to any known renormalization program. Some subtle and difficult issues can be easily resolved. The importance of the procedure for defining the ambiguities is fully appreciated in the new approach. Some simple but important nonperturbative examples are discussed to show the power and plausibility of the new approach.
13049479
A new kind of constraints on renormalization schemes
We derive a new kind of physical constraints on the subtraction schemes for theories with massive particles in addition to the Ward identities for gauge symmetries. The momentum subtraction scheme fails this criterion. The decoupling of heavy fields is discussed in the context of Callan-Symanzik equations where all schemes (including MOM) lead to the same pattern of decoupling with inevitable discontinuities in beta function across heavy field thresholds. PACS number(s): 11.10.Gh; 11.10.Hi; 12.39.Hg
120520076
Soliton mass and discrete coupling constants in the quantized sine-Gordon model
The soliton mass in the quantized sine-Gordon model over the whole range of the coupling constant (g2 from 0 to 8 pi ) is evaluated by means of the Gaussian effective potential method. The analytical expression with numerical results is presented. The authors find that the coupling constant g can only take discrete values. A new kind of soliton linking g Phi =0 to g Phi = pi emerges at a set of special coupling constants g.
14239579
Confinement of Higgs bosons from hidden symmetry and convexity
In the full effective potential (EFP) approach, we find that spontaneous symmetry breaking (SSB) can, with the convexity of the full EFP, lead to the prediction of the IR confinement of Higgs particles, adding difficulty to the experimental identification of Higgs particles. The short distance behaviors remain intact. The whole presentation is given in the understanding that any QFT becomes UV well defined in a more complete underyling theory according to a recently proposed strategy.
119274047
Structure function of holographic quark-gluon plasma: Sakai-Sugimoto model versus its noncritical version
Motivated by recent studies of deep inelastic scattering off the N = 4 super-Yang-Mills (SYM) plasma, holographically dual to an AdS(5) x S(5) black hole, we use the spacelike flavor current to probe the internal structure of one holographic quark-gluon plasma, which is described by the Sakai-Sugimoto model at high temperature phase (i.e., the chiral-symmetric phase). The plasma structure function is extracted from the retarded flavor current-current correlator. Our main aim in this paper is to explore the effect of nonconformality on these physical quantities. As usual, our study is under the supergravity approximation and the limit of large color number. Although the Sakai-Sugimoto model is nonconformal, which makes the calculations more involved than the well-studied N = 4 SYM case, the result seems to indicate that the nonconformality has little essential effect on the physical picture of the internal structure of holographic plasma, which is consistent with the intuition from the asymptotic freedom of QCD at high energy. While the physical picture underlying our investigation is same as the deep inelastic scattering off the N = 4 SYM plasma with(out) flavor, the plasma structure functions are quantitatively different, especially their scaling dependence on the temperature, which can be recognized as model dependent. As a comparison, we also do the same analysis for the noncritical version of the Sakai-Sugimoto model which is conformal in the sense that it has a constant dilaton vacuum. The result for this noncritical model is quite similar to the conformal N = 4 SYM plasma. We therefore attribute the above difference to the effect of nonconformality of the Sakai-Sugimoto model.
96462689
Can MSSM with light sbottom and light gluino survive $Z$ peak constraints?
In the framework of the minimal supersymmetric model we examine the Z-peak constraints on the scenario of one light bottom squark (sbottom) (similar to2-5.5 GeV) and light gluino (similar to12-16 GeV) which has been successfully used to explain the excess of bottom quark production in hadron collisions. Such a scenario is found to be severely constrained by the CERN LEP Z-peak observables, especially by R-b, due to the large effect of gluino-sbottom loops. To account for the Rb data in this scenario, the other mass eigenstate of sbottom, i.e., the heavier one, must be lighter than 125 ( 195) GeV at 2sigma(3sigma) level, which, however, is disfavored by CERN LEP II experiments.
125300279
Possible new physics forms for Z b anti-b couplings
116807085
Bogomolny Field Equations and the Double-Complex Function Method
The double-complex function method is applied tothe Bogomolny field equations ofYang–Mills–Higgs theory. We discuss how togenerate a family of solutions of the Bogomolny fieldequations with a double-complex Ernst potential. We discuss the application ofthe Neugebauer–Kramer transformation, the doubleEhlers transformation, and noncommutativity. An exampleof a concrete calculation is given.
2551792
Low-scale SU(4)W unification
We embed the minimal left-right model SU(2) L x SU(2) R x U(1)B-L into an SU(4) W gauge group, and break the unified group via five-dimensional S(1)/(Z(2) x Z2) orbifolding. Leptons are fitted into SU(4)(W) multiplets and located on a symmetry preserving O brane, while quarks are placed onto an O' brane where the symmetry is broken. This approach predicts sin(2) theta(W) = 0.25 for the weak mixing angle at tree level and leads to a rather low weakly ( strongly) coupled unification scale of order 3 x 10(2) TeV (several TeV) with supersymmetry, or as low as several TeV in the non-supersymmetric case. Another symmetry breaking chain with the low-energy gauge group SU(2)(L) x U(1)(3R) x U(1)(B-L) can also give rise to a weak mixing angle sin 2. W = 0.25 at tree level after gauge symmetry breaking by orbifolding. Such theories with low-scale unification have interesting phenomenological consequences.