5169223
On the renormalization of effective field theories for nucleon-nucleon interactions
The renormalization in nonperturbative regimes are investigated in a compact and general parametrization of the T -matrix for nucleon-nucleon scattering. The underlying theory perspective and the ’fixing’ of the prescriptions for the T -matrix from physical boundary conditions are stressed with various existing schemes briefly addressed.
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.
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.
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.
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
36032236
Lepton flavor violating Z-decays in supersymmetric seesaw model
Abstract.In the supersymmetric seesaw model, large flavor mixings of sleptons induce the lepton flavor violating (LFV) interactions $\ell_I \bar\ell_J V$ ($V = \gamma, Z$), which give rise to various LFV processes. In this work we examine the LFV decays $Z\to\ell_I \bar\ell_J$. Subject to the constraints from the existing neutrino oscillation data and the experimental bounds on the decays $\ell_J\to\ell_I\gamma$, these LFV Z-decays are found to be sizable, and among them the largest-rate channel $Z\to \tau \bar{\mu}$ can occur with a branching ratio of 10-8 and may be accessible at the LHC or GigaZ experiment.
122033631
An analytical study of lattice gauge theory at finite temperature
Abstract We extended the variational cumulant expansion for lattice gauge theories to finite temperature. The phase diagram of the Z(2) gauge model is given in four dimensions. The asymmetric Z(2) model at finite temperature is also treated.
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.
125826939
One loop effects of supersymmetry on $Z$ decays into $b \bar{b}$
Virtual effects of supersymmetry on the partial width and on the branching ratio are calculated in the minimal supersymmetric standard model. We found that the virtual gluino contribution to the width is negligibly small if the squark and gluino masses take their experiment-allowed values. Also, we have calculated the contributions to Rb from the charged Higgs and charginos. As to the discrepancy between two previous works about the virtual chargino correction, our calculations provide a confirmation.
118552829
New physics effects on top quark spin correlation and polarization at the LHC: A comparative study in different models
Extensions of the standard model often predict new chiral interactions for top quarks, which will contribute to top quark spin correlation and polarization in t (t) over bar production at the LHC. In this work, under the constraints from the current Tevatron measurements, a comparative study of the spin correlation and polarization is performed in three new physics models: the minimal supersymmetric model without R-parity, the third-generation enhanced left-right model, and the axigluon model. We find that the polarization asymmetry may be enhanced to the accessible level in all these models, while the correction to the spin correlation may be detectable in the axigluon model and the minimal supersymmetric model without R-parity with lambda '' couplings.