10526710
Trace and chiral anomalies in QED and their underlying theory interpretation
Parametrizing the possible underlying theory or new physics' decoupling effects in the most general way we reexamined the validity of canonical trace relation and chiral symmetry in certain one-loop two-point functions. The anomalies and the relation between chiral and trace Ward identities are investigated and interpreted in the perspective of a complete underlying theory or new physics instead of regularization, with some new phenomena found as by-products.
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.
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
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.
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.
119115457
Light dark matter in NMSSM and implication on Higgs phenomenology
For the experimental search of neutralino dark matter, it is important to know its allowed mass and scattering cross section with the nucleon. In order to figure out how light a neutralino dark matter can be predicted in low energy supersymmetry, we scan over the parameter space of the NMSSM (next-to-minimal supersymmetric model), assuming all the relevant soft mass parameters to be below TeV scale. We find that in the parameter space allowed by current experiments the neutralino dark matter can be as light as a few GeV and its scattering rate off the nucleon can reach the sensitivity of XENON100 and CoGeNT. As a result, a sizable parameter space is excluded by the current XENON100 and CoGeNT data (the plausible CoGeNT dark matter signal can also be explained). The future 6000 kg-days exposure of XENON100 will further explore (but cannot completely cover) the remained parameter space. Moreover, we find that in such a light dark matter scenario a light CP-even or CP-odd Higgs boson must be present to satisfy the measured dark matter relic density. Consequently, the SM-like Higgs boson h(SM) may decay predominantly into a pair of light Higgs bosons or a pair of neutralinos so that the conventional decays like h(SM) -> gamma gamma is much suppressed. (C) 2011 Elsevier B.V. All rights reserved.
125300279
Possible new physics forms for Z b anti-b couplings
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.
123742445
The Deconfinement Transition in SU(2) Lattice Gauge Theory: An Analytical Study
We study SU(2) lattice gauge theory at finite temperature in the variational cumulant expansion approach. The deconfinement transition is given in four and five dimensions. The comparison with Monte Carlo results is also presented.
118350624
R-parity violating effects in top quark FCNC productions at LHC
In the minimal supersymmetric model the R-parity violating top quark interactions, which are so far weakly constrained, can induce various flavor-changing neutral-current (FCNC) productions for the top quark at the Large Hadron Collider (LHC). In this work we assume the presence of the B-violating couplings and examine their contributions to the FCNC productions proceeding through the parton processes cg → t, gg → tc̄, cg → tγ, cg → tZ and cg → th. We find that all these processes can be greatly enhanced relative to the R-parity preserving predictions. In the parameter space allowed by current experiments, all the production channels except cg → th can reach the 3σ sensitivity, in contrast to the R-parity preserving case in which only cg → t can reach the 3σ sensitivity. PACS numbers: 14.65.Ha,14.80.Ly,11.30.Hv