117884871
Coarse graining and renormalization
Formulating the QFT's as coarse grained 'low' energy sectors of a postulated complete quantum theory of everything with the 'high' energy modes integrated out or 'clustering' into 'low' energy objects, we can evaluate the Feynman amplitudes by solving a series of natural differential equations which automatically dissolves the necessity of infinity subtraction and the associated subtleties. This new strategy has direct implications to the scheme dependence problem.
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.
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
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.
15717462
Dimension-six CP-violating operators of the third-family quarks and their effects at colliders
We list all possible dimension-six $\mathrm{CP}$-violating ${\mathrm{SU}}_{c}(3)\ifmmode\times\else\texttimes\fi{}{\mathrm{SU}}_{L}(2)\ifmmode\times\else\texttimes\fi{}{\mathrm{U}}_{Y}(1)$-invariant operators involving the third-family quarks, which can be generated by new physics at a higher energy scale. The expressions of these operators after electroweak symmetry breaking and the induced effective couplings $\mathrm{Wt}\overline{b}$, $\mathrm{Xb}\overline{b}$, and $\mathrm{Xt}\overline{t}$ $(X=Z,\ensuremath{\gamma},g,H)$ are also presented. We evaluate sample contributions of these operators to $\mathrm{CP}$-odd asymmetries of transverse polarization of the top quark in single top quark production at the upgraded Fermilab Tevatron, the same polarization effect in top-quark\char21{}top-antiquark pair production at the NLC, and the $\mathrm{CP}$-odd observables of momentum correlations among the top quark decay products at the NLC. The energy and luminosity sensitivity in probing this $\mathrm{CP}$-violating new physics is also studied.
119201106
Semi-direct Gauge-Yukawa mediation
We propose semi-direct Gauge-Yukawa mediation of supersymmetry (SUSY) breaking. The messenger fields mediating SUSY breaking to the visible sector do not directly couple with the goldstino field, and instead they have gauge and Yukawa interactions with some primary messenger fields which couple directly with the goldstino fields. From the explicit Feynman diagram calculations for the SUSY breaking soft masses, we find that the SUSY particle spectra can be realistic. Especially, this generalization of semi-direct gauge mediation solves the massless gaugino mass problem since the holomorphic soft mass terms of the messenger fields can be generated by Yukawa couplings. We also provide some arguments that this scenario can be realized naturally in some dynamical SUSY-breaking models such as the ISS-like model.
17604385
The SU(3)(C) x SU(4)(W) x U(1)B-L models with left-right unification
Abstract To understand the origin of the left–right symmetry, we study a partial unification model based on SU ( 4 ) W × U ( 1 ) B − L which can be broken down to the minimal left–right model either through the Higgs mechanism in four dimensions or through the five-dimensional orbifolding gauge symmetry breaking, especially we propose to use the rank reducing outer automorphism orbifolding breaking mechanism. We scrutinized all these breaking mechanisms and found that for the orbifold breaking in five dimensions, the rank-reducing outer automorphism is better than the inner automorphism and can make the low energy theory free of the U ( 1 ) Z anomaly. It is possible for the outer automorphism orbifolding breaking mechanism to be non-anomalous without Chern–Simons terms and new localized fermions. For the four-dimensional model with the Higgs mechanism, we study in detail both its structure and its typical phenomenology. It turns out that this four-dimensional scenario may predict some new phenomenology since the new mirror fermions (which are introduced in order to fill the SM fermions into SU ( 4 ) W without anomaly) are preserved at low energy scale and mix with the SM fermions. We also examine the gauge coupling unification in each case, and discuss the possibility for unifying this partial unification group with the Pati–Salam group SU ( 4 ) PS to realize a grand unification.
118912746
B-meson dileptonic decays enhanced by supersymmetry with large tan beta
We examined the rare decays B --> X(x)e(+)e(-) and B-x --> e(+)e(-)gamma in the minimal supersymmetric model with large tan beta. Taking into account the effects of the gluino-loop and neutralino-loop with neutral Higgs exchange, we found that for a large tan beta the neutral Higgs exchanging diagrams could enhance Br(B --> X(s)tau(+)tau(-)) by a factor of 5 and Br(B-s --> tau(+)tau(-)gamma) by a couple of orders in some part of supersymmetric parameter space allowed by current experiments such as b --> sgamma, B --> K((*))e(+)e(-) and B-s --> e(+)e(-). The forward-backward asymmetry and the distributions of differential branching ratios are also found to differ significantly from the standard model results. Such enhanced branching ratios reach the level of 10(-5) and thus might be observable in the new generation of B experiments. (C) 2002 Elsevier Science B.V. All rights reserved.
14522743
Supersymmetric QCD corrections to single top quark production at the Fermilab Tevatron
We evaluate the supersymmetric QCD corrections to single top quark production via q{bar q}{sup {prime}}{r_arrow}t{bar b} at the Fermilab Tevatron in the minimal supersymmetric model. We find that within the allowed range of squark and gluino masses the supersymmetric QCD corrections can enhance the cross section by a few percent. The combined effects of SUSY QCD, SUSY EW, and the Yukawa couplings can exceed 10{percent} for the smallest allowed tan{beta}({approx_equal}0.25) but are only a few percent for tan{beta}{gt}1. {copyright} {ital 1997} {ital The American Physical Society}