122863740
Finiteness of Chern-Simons theory and fermion decoupling in 2 + 1-dimensional SU(N) gauge field theory
Abstract We discuss the decoupling of heavy fermions in SU( N ) gauge field theory (GFT) in 2 + 1-dimensional spacetime. The pure Chern-Simons (CS) theory may be seen as the resulting theory when the charge of the gauge field also goes to infinity. Then the finiteness of the CS theory or the vanishing of the beta function of the CS coefficient ϰ cs with or without matter, is proved in this approach.
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.
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.
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.
123073091
An analytical study of U(1) gauge-Higgs theory on a lattice
Lattice U(1) gauge-Higgs theory is studied in the variational cumulant expansion approach. The phase structures are given for this theory with different charges. A comparison with Monte Carlo results is also presented.
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.
119077959
Probing natural SUSY from stop pair production at the LHC
A bstractWe consider the natural supersymmetry scenario in the framework of the R-parity conserving minimal supersymmetric standard model (called natural MSSM) and examine the observability of stop pair production at the LHC. We first scan the parameters of this scenario under various experimental constraints, including the SM-like Higgs boson mass, the indirect limits from precision electroweak data and B-decays. Then in the allowed parameter space we study the stop pair production at the LHC followed by the stop decay into a top quark plus a lightest neutralino or into a bottom quark plus a chargino. From detailed Monte Carlo simulations of the signals and backgrounds, we find the two decay modes are complementary to each other in probing the stop pair production, and the LHC with $ \sqrt{s}=14 $ TeV and 100 fb−1 luminosity is capable of discovering the stop predicted in natural MSSM up to 450 GeV. If no excess events were observed at the LHC, the 95% C.L. exclusion limits of the stop masses can reach around 537 GeV.
119412299
Higgs-boson production associated with a bottom quark at hadron colliders with supersymmetric QCD corrections
The Higgs boson production pp(p (p) over bar)-->bh+X via bg-->bh at hadron colliders, which may be an important channel for testing the bottom quark Yukawa coupling, is subject to large supersymmetric quantum corrections. In this work the one-loop supersymmetric (SUSY) QCD corrections to this process are evaluated and are found to be quite sizable in some parameter space. We also study the behavior of the corrections in the limit of heavy SUSY masses and find the remnant effects of SUSY QCD. These remnant effects, which are left over in the Higgs sector by the heavy sparticles, are found to be so sizable (for a light CP-odd Higgs boson and large tan beta) that they might be observable in future experiments. The exploration of such remnant effects is important for probing SUSY, especially in the case that the sparticles are too heavy (above TeV) to be directly discovered in future experiments.
18499959
An extension for direct gauge mediation of metastable supersymmetry breaking
We study the direct mediation of metastable supersymmetry breaking by a Φ2-deformation to the ISS model and extend it by splitting both TrΦ and TrΦ2 terms in the superpotential and gauging the flavor symmetry. We find that with such an extension enough-long-lived metastable vacua can be obtained and the proper gaugino masses can be generated. Also, this allows for constructing a kind of models which can avoid the Landau pole problem. Especially, in our metastable vacua there exist a large region for the parameter m3 which can satisfy the phenomenology requirements and allow for a low SUSY-breaking scale (hμ2~100 TeV).