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Jose Wudka

Publications and source records attributed to Jose Wudka.

At least 73 records · Page 4Linked to original sources
arXiv2004

CP Violation from 5-dimensional QED

It has been shown that QED in (1+4)-dimensional space-time, with the fifth dimension compactified on a circle, leads to CP violation (CPV). Depending on fermionic boundary conditions, CPV may be either explicit (through the Scherk--Schwarz mechanism), or spontaneous (via the Hosotani mechanism). The fifth component of the gauge field acquires (at the one-loop level) a non-zero vacuum expectation value. In the presence of two fermionic fields, this leads to spontaneous CPV in the case of CP-symmetric boundary conditions. Phenomenological consequences are illustrated by a calculation of the electric dipole moment for the fermionic zero-modes.

hep-ph↗
arXiv2003

Higgs-Boson Mass Limits and Precise Measurements beyond the Standard Model

The triviality and vacuum stability bounds on the Higgs-boson mass ($\mh$) were revisited in presence of weakly-coupled new interactions parameterized in a model-independent way by effective operators of dimension 6. The constraints from precision tests of the Standard Model were taken into account. It was shown that for the scale of new physics in the region $Λ\simeq 2 ÷50 \tev$ the Standard Model triviality upper bound remains unmodified whereas it is natural to expect that the lower bound derived from the requirement of vacuum stability is substantially modified depending on the scale $\La$ and strength of coefficients of effective operators. A natural generalization of the standard triviality condition leads also to a substantial reduction of the allowed region in the ($Λ,\mh$) space.

hep-ph↗
arXiv2003

Triviality and stability limits on the Higgs boson mass in effective theories

The impact of new interactions on the triviality and stability Higgs-boson mass bounds has been studied. The interactions have been parame- trized in a model-independent way by a set of effective operators of dimension 6. Constraints from electroweak observables at 1-loop level have been included. In the analyzed region of scale of new physics $\La \simeq 2 ÷50 \tev$ the classic triviality bound remains unchanged. An extension of the triviality condition that has been introduced leads to strong constraints on the possible models. The stability bound on the Higgs boson mass is substantially modified depending on the scale $\La$ and strength of coefficients of relevant effective operators.

hep-ph↗
arXiv2003

Natural and model-independent conditions for evading the limits on the scale of new physics

I argue that the limits on this quantity obtained using model-independent parameterizations contain an tacit assumption that could be invalidated under a variety of situations. As a specific example, existing limits on $Λ$ would be decreased by at least an order of magnitude if the underlying physics has a symmetry under which all \sm particles are singlets but none of the heavy excitations are. In this case current experiments would see no clear indications of new physics using precision measurements while future colliders capable of directly producing the heavy particles would only occur in pairs.

hep-ph↗
arXiv2001

Triviality and Vacuum Stability Bounds on the Higgs Boson Mass beyond the Standard Model

The triviality and vacuum stability bounds on the Higgs-boson mass were revisited in presence of weakly-coupled new interactions parameterized in a model-independent way by effective operators of dimension 6. It was shown that for the scale of new physics in the region Lambda=.5-50 TeV the Standard Model triviality upper bound remains unmodified whereas it is natural to expect that the lower bound derived from the requirement of vacuum stability is increased by 40-60 GeV depending on the scale Lambda and strength of coefficients of effective operators. It turns out that if the Higgs-boson mass is close to its lower LEP limit then the upper bound on the scale of new physics that follows from the vacuum stability requirement would be decreased dramatically even for modest values of coefficients of effective operators implying new physics already at the scale of a few TeV.

hep-ph↗
arXiv2001

Consistency bounds on the Higgs-boson mass

In this talk we consider the modifications induced by heavy physics on the triviality and vacuum stability bounds on the Higgs-boson mass. We parameterize the heavy interactions using an effective Lagrangian and find that the triviality bound is essentially unaffected for weakly-coupled heavy physics. In contrast there are significant modifications in the stability bound that for a light Higgs boson require a scale of new physics of the order of a few TeV.

hep-ph↗
arXiv2001

Triviality and stability in effective theories

In this talk we consider the modifications induced by heavy physics on the triviality and vacuum stability bounds on the Higgs-boson mass. We parameterize the heavy interactions using an effective Lagrangian and find that the triviality bound is essentially unaffected for weakly-coupled heavy physics. In contrast there are significant modifications in the stability bound that for a light Higgs boson require a scale of new physics of the order of a few TeV.

hep-ph↗
arXiv2001

Effective Beta-Functions for Effective Field Theory

We consider the problem of determining the beta-functions for any reduced effective field theory. Even though not all the Green's functions of a reduced effective field theory are renormalizable, unlike the full effective field theory, certain effective beta- functions for the reduced set of couplings may be calculated without having to introduce vertices in the Feynman rules for redundant operators. These effective beta-functions suffice to apply the renormalization group equation to any transition amplitude (i.e., S- matrix element), thereby rendering reduced effective field theories no more cumbersome than traditionally renormalizable field theories. These effective beta-functions may equally be regarded as the running of couplings for a particular redefinition of the fields.

hep-ph↗
arXiv2001

Bounds on the Higgs-Boson Mass in the Presence of Non-Standard Interactions

The triviality and vacuum stability bounds on the Higgs-boson mass are revisited in the presence of new interactions parameterized in a model-independent way by an effective lagrangian. When the scale of new physics is below 50 TeV the triviality bound is unchanged but the stability lower bound is increased by 40-60 GeV. Should the Higgs-boson mass be close to its current lower experimental limit, this leads to the possibility of new physics at the scale of a few TeV, even for modest values of the effective lagrangian parameters.

hep-ph↗
arXiv2001

Mass dependence of the gravitationally-induced wave-function phase

The leading mass dependence of the wave function phase is calculated in the presence of gravitational interactions. The conditions under which this phase contains terms depending on both the square of the mass and the gravitational constant are determined. The observability of such terms is briefly discussed.

gr-qc↗
arXiv2000

CP violation in gauge theories

We define the CP transformation properties of scalars, fermions and vectors in a gauge theory and show that only three types of interactions can lead to CP violation: scalar interactions, fermion-scalar interactions and $ F \tilde F $ associated with the strong CP problem and which involve only the gauge fields. For technicolor theories this implies the absence of CP violation within perturbation theory.

hep-ph↗
arXiv1998

Study of Trilinear Gauge Boson Couplings at the Tevatron Collider

We review studies of the trilinear gauge boson couplings at the Tevatron proton-antiproton collider from data collected by the CDF and D0 collaborations during the period 1992--1996. The gauge boson couplings are a fundamental prediction of the standard model, resulting from the non-Abelian nature of the theory. Therefore, experimental tests of the couplings are of foremost importance. We introduce the experimental results by reviewing the effective Lagrangian formalism, the indirect constraints on the couplings from low-energy experiments, and the expected values of the couplings in theories beyond the standard model. Finally, we consider the prospects for future measurements.

hep-ph↗
arXiv1998

Enhanced Three-Body Decay of the Charged Higgs Boson

If the charged Higgs boson H+ exists with mh < mt + mb, the conventional expectation is that it will decay dominantly into c s-bar and tau+ nu-tau. However, the three-body decay mode H+ --> W+ b b-bar is also present and we show that it becomes very important in the low tan(beta) region for mh >~ 140 GeV. We explore its phenomenological implications for the charged-Higgs-boson search in top-quark decay.

hep-ph↗
arXiv1997

Effective operators in Supersymmetry

We consider a low-energy supersymmetric scenario in which the effects of heavy supersymmetric interactions are included in a model-independent manner through a series of supersymmetric SU(3)_C*SU(2)_L*U(1)_Y invariant operators; we explicitly construct all such operators of dimension less or equal than 6. From this set, those operators generated at tree level by the underlying theory are isolated since under weak coupling conditions they are expected to provide the largest effects in low-energy processes. Potential deviations from low energy predictions in process such as proton decay, neutrinoless double-beta decay and flavor changing neutral currents are analyzed as illustrations of the method.

hep-ph↗
arXiv1997

Non-standard t production at the NLC

The top-quark system as a probe for new physics is considered using a consistent, gauge-invariant effective Lagrangian approach. The magnitude of new effects is estimated and the results are applied to top production through W fusion. Other processes are also briefly discussed.

hep-ph↗