publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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1994-12-24 | Strong coupling analysis of the large-N 2-d lattice chiral models | Two dimensional large-N chiral models on the square and honeycomb lattices
are investigated by a strong coupling analysis. Strong coupling expansion turns
out to be predictive for the evaluation of continuum physical quantities, to
the point of showing asymptotic scaling. Indeed in the strong coupling region a
quite la... | 9412101v1 |
1995-02-01 | Two-loop relation between the bare lattice coupling and the MSbar coupling in pure SU(N) gauge theories | We report the result of a computation of the relation between the
renormalized coupling in the MSbar scheme of dimensional regularization and the
bare coupling in the standard lattice formulation of the SU(N) Yang-Mills
theory to two-loop order of perturbation theory and discuss some of its
implications. | 9502001v1 |
1995-05-12 | Computation of the relation between the bare lattice coupling and the MSbar coupling in SU(N) gauge theories to two loops | The perturbation expansion of the MSbar coupling in the SU(N) gauge theory in
powers of the bare lattice coupling is extended to two-loop order. A discussion
of our results has already been published elsewhere. We here describe the
calculation in some detail. It relies on the background field technique and a
recently i... | 9505011v1 |
1995-11-21 | Singular Vertices in the Strong Coupling Phase of Four--Dimensional Simplicial Gravity | We study four--dimensional simplicial gravity through numerical simulation
with special attention to the existence of singular vertices, in the strong
coupling phase, that are shared by abnormally large numbers of four--simplices.
The second order phase transition from the strong coupling phase into the weak
coupling p... | 9511023v1 |
1996-05-28 | Phase diagram of Regge quantum gravity coupled to SU(2) gauge theory | We analyze Regge quantum gravity coupled to SU(2) gauge theory on $4^3\times
2$, $6^{3}\times 4$ and $8^{3}\times 4$ simplicial lattices. It turns out that
the window of the well-defined phase of the gravity sector where geometrical
expectation values are stable extends to negative gravitational couplings as
well as to... | 9605036v1 |
1997-10-10 | Two loop expansion of the Schroedinger functional coupling alpha_SF in SU(3) lattice gauge theory | The two loop coefficient of the expansion of the Schroedinger functional
coupling in terms of the lattice coupling is calculated for the SU(3)
Yang-Mills theory. This coefficient is required to relate lattice data to the
MS-bar-coupling. As a byproduct of the calculation, the Schroedinger functional
is improved to two ... | 9710043v1 |
1999-12-14 | Hamiltonian domain wall fermions at strong coupling | We apply strong-coupling perturbation theory to gauge theories containing
domain-wall fermions in Shamir's surface version. We construct the effective
Hamiltonian for the color-singlet degrees of freedom that constitute the
low-lying spectrum at strong coupling. We show that the effective theory is
identical to that de... | 9912019v2 |
2000-05-01 | Center Vortices at Strong Couplings and All Couplings | Motivations for the center vortex theory of confinement are discussed. In
particular, it is noted that the abelian dual Meissner effect, which is the
signature of dual superconductivity, cannot adequately describe the confining
force at large distance scales. A long-range effective action is derived from
strong-couplin... | 0005001v1 |
2000-12-28 | Phase Structure of the 5D Abelian Higgs Model with Anisotropic Couplings | We establish the phase diagram of the five-dimensional anisotropic Abelian
Higgs model by mean field techniques and Monte Carlo simulations. The
anisotropy is encoded in the gauge couplings as well as in the Higgs couplings.
In addition to the usual bulk phases (confining, Coulomb and Higgs) we find
four-dimensional ``... | 0012028v1 |
2001-10-11 | Investigation of gauge-fixed pure U(1) theory at strong coupling | We numerically investigate the phase diagram of pure U(1) gauge theory with
gauge fixing at strong gauge coupling. The FM-FMD phase transition, which
proved useful in defining Abelian lattice chiral gauge theory, persists also at
strong gauge coupling. However, there the transition seems no to be longer
continuous. At ... | 0110043v1 |
2004-09-23 | Domain-Wall Fermions at Strong Coupling | The DWF formulation becomes increasingly problematic at gauge couplings for
which $a^{-1}<2$ GeV, where the roughness of the gauge field leads to increased
explicit chiral symmetry breaking ($\mres$). This problem becomes especially
severe for sufficiently strong coupling where the underlying 4-dimensional
Wilson theor... | 0409143v1 |
2005-02-23 | Running coupling of 2-flavor QCD at zero and finite temperature | We present lattice studies of the running coupling in 2-flavor QCD. The
coupling at zero temperature (T=0) is extracted from Wilson loops while the
coupling at finite temperature ($T\neq0$) is determined from Polyakov loop
correlation functions. | 0502012v2 |
2005-12-19 | The behavior of the sextic coupling for the scalar field at the intermediate and strong coupling regime | We study the behavior of the renormalized sextic coupling at the intermediate
and strong coupling regime for the $\phi^4 $ theory defined in $d=2$-dimension.
We found a good agreement with the results obtained by the field-theoretical
renormalization-group in the Ising limit. In this work we use the lattice
regularizat... | 0512024v1 |
2006-08-21 | The spectrum of lattice QCD with staggered fermions at strong coupling | Using 4 flavors of staggered fermions at infinite gauge coupling, we compare
various analytic results for the hadron spectrum with exact Monte Carlo
simulations. Agreement with Ref. \cite{Martin_etal} is very good, at the level
of a few percent.
Our results give credence to a discrepancy between the baryon mass and t... | 0608012v1 |
1992-09-21 | CP Violating Form Factors for Three Gauge Boson Vertex in the Two Higgs Doublet and Left-Right symmetric Models | In this paper we calculate the one loop contributions to the CP violating
three gauge boson couplings in two-Higgs doublet and Left--Right symmetric
models. In the two-Higgs doublet model only a P conserving and CP violating
coupling is generated, and it can be large as $10^{-3}$. In the Left--Right
symmetric model bot... | 9209260v1 |
1993-02-24 | Masses, Mixings, Yukawa Couplings and their Symmetries | We present a method to find the number of real and imaginary observable
parameters coming from the Yukawa sector in an arbitrary gauge theory. The
method leads naturally to a classification of Yukawa couplings according to
their symmetries and suggests a new parametrization of masses and mixings that
is useful to study... | 9302301v1 |
1993-06-10 | Anomalous $WWZ$ couplings and $K_L\rightarrow μ^+ μ^-$ | We study contributions to $K_L \rightarrow \mu^+\mu^-$ from anomalous $WWZ$
interactions. There are, in general, seven anomalous couplings. Among the seven
anomalous couplings, only two of them contribute significantly. The others are
suppressed by factors like $m_s^2/M_W^2$, $m_d^2$, or $m_K^2/M_W^2$. Using the
experi... | 9306254v3 |
1994-05-12 | Probing the Couplings of the Top Quark to Gauge Bosons | We parameterize the non-universal couplings of t-t-Z and t-b-W in the
electroweak chiral lagrangian approach, and examine the constraints on these
parameters from the LEP data. We also study how the SLC, Tevatron, LHC and NLC
can improve the measurement of these couplings. Different symmetry breaking
scenarios imply di... | 9405277v1 |
1994-05-21 | Anomalous Vector-Boson Couplings in Majorana Neutrino Models | We examine the contributions of Majorana neutrinos to CP-violating WWZ and
ZZZ self-couplings, using a model in which sterile neutrinos couple to the W
and Z by mixing with a fourth-generation heavy lepton. We find that the induced
form factors can be as large as 0.5%. The model satisfies all phenomenological
bounds in... | 9405349v1 |
1994-10-25 | Bounds on Anomalous Gauge Boson Couplings From Partial Z Widths at LEP | We place bounds on anomalous gauge boson couplings from LEP data with
particular emphasis on those couplings which do not contribute to $Z$ decays at
tree level. We use an effective field theory formalism to compute the one-loop
corrections to the $Z\rightarrow {\overline f} f$ decay widths resulting from
non-standard ... | 9410364v1 |
1994-12-09 | CP Violation and the Width $Z\rightarrow b\bar{b}$ | We discuss the effect of CP-violating $Zb\bar{b}$, $Zb\bar{b}G$ and
$Zb\bar{b}\gamma$ couplings on the width $\Gamma(Z\rightarrow b\bar bX)$. The
presence of such couplings leads in a natural way to an increase of this width
relative to the prediction of the standard model. Various strategies of a
direct search for suc... | 9412268v1 |
1995-02-16 | Constraining the Strongly-Coupled Standard Model Including a W' Isotriplet | We consider the Strongly-Coupled Standard Model (Abbott-Farhi model)
including an isotriplet of W' vector bosons. First we calculate the corrections
to the low-energy theory, which can be effectively summarized in terms of the
parameters S, T and U. Then we use high- precision electroweak measurements to
constrain the ... | 9502331v1 |
1995-06-12 | Axion-photon Couplings in Invisible Axion Models | We reexamine the axion-photon couplings in various invisible axion models
motivated by the recent proposal of using optical interferometry at the ASST
facility in the SSCL to search for axion. We illustrate that the assignment of
$U(1)_{PQ}$ charges for the fermion fields plays an important role in
determining the coup... | 9506295v1 |
1995-06-16 | Chiral symmetry breaking in strongly coupled scalar QED | Scalar QED with fermions is investigated in an expansion in powers of the
inverse gauge coupling constant. The fermion mass generation is studied in next
to leading order of the strong coupling expansion for the Higgs-phase of the
model. Chiral symmetry breaking is discussed. Our approach supports from a
strong couplin... | 9506341v1 |
1995-10-17 | New Bounds on R-Parity Violating Couplings | Bounds on R-parity violating couplings in the supersymmetric standard model
are reviewed, and some new bounds arising from non-observation of certain rare
B-decays (such as $B \rightarrow K^+K^-$) are presented. The focus is on
baryon-number violating couplings, but it is also noted that many products of
lepton- number... | 9510320v1 |
1996-01-11 | Dynamical Gauge Coupling Constants | In string theory the coupling parameters are functions of moduli fields. The
actual values of the coupling constants are then dynamically determined through
the vacuum expextation values of these fields. We review the attempts to
connect such theories to low energy effective field theories with realistic
gauge coupling... | 9601241v1 |
1996-07-07 | Relativistic Coulomb Problem: Energy Levels at the Critical Coupling Constant Analytically | The Hamiltonian of the spinless relativistic Coulomb problem combines the
standard Coulomb interaction potential with the square-root operator of
relativistic kinematics. This Hamiltonian is known to be bounded from below up
to some well-defined critical coupling constant. At this critical coupling
constant, however, t... | 9607249v1 |
1996-11-26 | CP violating couplings in Z -> 3 jet decays revisited | Possible CP violating effects in $Z\rightarrow$ 3 jet decays are
investigated. The analysis assumes the presence of CP violating $Zq\bar qG$
couplings. The contribution of these couplings to the $Z\rightarrow q\bar qG$
decay width is calculated for different cut algorithms, including nonzero quark
masses. Various CP--o... | 9611430v1 |
1997-01-31 | An extension of the standard model with a single coupling parameter | We show that it is possible to find an extension of the matter content of the
standard model with a unification of gauge and Yukawa couplings reproducing
their known values. The perturbative renormalizability of the model with a
single coupling and the requirement to accomodate the known properties of the
standard mode... | 9702204v1 |
1997-08-22 | Negative coupling instability and grandunified baryogenesis | I review my recent work with Brian Greene and Thomas Roos. First I discuss
the effect of a negative cross-coupling on the inflaton decay in two scalar
field theories. Our main finding is a new effect, the negative coupling
instability, which leads to explosive particle production and very fast
inflaton decay. Then I di... | 9708428v1 |
1997-10-01 | Model independent analysis of the trilinear gauge boson couplings at LC: role of polarized cross sections | By means of a model-independent analysis, we discuss the constraints on
anomalous trilinear gauge-boson couplings that can be obtained from the study
of electron-positron annihilation into $W$ pairs at LC with \sqrt{s}=0.5 TeV
and 1 TeV. We consider the general CP conserving anomalous effective
Lagrangian, as well as s... | 9710215v1 |
1997-11-02 | Excited Baryons Phenomenology from Large-$N_c$ QCD | We present a phenomenological analysis of the strong couplings of the
negative-parity L=1 baryons from the perspective of the large-$N_c$ expansion.
In the large-$N_c$ limit the mass spectrum and mixing pattern of these states
are constrained in a very specific way. The mixing angles are completely
determined in this l... | 9711201v1 |
1998-01-20 | Indications for an Anomalous Right-Handed Coupling of the b-Quark from a Model Independent Analysis of LEP and SLD Data on Z-Decays | A model independent analysis is made using the LEP and SLD data on Z decays
available at the end of 1996. The effective weak coupling constants of leptons,
c quarks and b quarks are extracted. Except for the right-handed b quark
coupling, they all agree well with the predictions of the Standard Electroweak
Model for $m... | 9801355v2 |
1998-06-03 | Flavour symmetry of mesonic decay couplings | We present flavour-symmetric results for the couplings of quark-antiquark
systems to meson-meson channels in the harmonic-oscillator expansion. We
tabulate their values for all possible open and closed decay channels of
pseudo-scalar, vector and scalar mesons. We compare the predictions of a model
that employs these fl... | 9806248v3 |
1998-10-13 | Violation of SUSY equivalence in triple gauge boson and gaugino couplings | Supersymmetry implies that the trilinear couplings between gauge bosons and
gauginos are equal to all orders in perturbation theory. However if SUSY is
broken and some of the superpartners have large SUSY breaking masses then they
can induce non-decoupling deviations in this relation through radiative
corrections. In t... | 9810344v1 |
1998-11-19 | Quark Gluon Plasma as a Strongly Coupled Color-Coulombic Plasma | We show that the extensively studied equation of state (EOS) of strongly
coupled QED plasma fits the recent lattice EOS data of gluon plasma remarkably
well, with appropriate modifications to take account of color degrees of
freedom and running coupling constant. Hence we conclude that the quark gluon
plasma near the c... | 9811397v1 |
1999-01-10 | Pionic coupling constants of heavy mesons in the quark model | We analyse pionic couplings of heavy mesons combining PCAC with the
dispersion quark model to calculate the relevant transition form factors.
Ground states and radial excitations are considered. For the ground state
coupling constants the values $\hat g=0.5\pm0.02$ in the heavy quark limit,
$g_{B^*B\pi}=40\pm 3$, $g_{D... | 9901261v1 |
1999-01-19 | CP Violation in Decays Z --> 4 Jets | We analyse CP-violating effects in Z \to 4 jet decays, assuming the presence
of CP-violating effective $Z b \bar{b} G$ and $Z b \bar{b} G G$ couplings. We
discuss the influence of these couplings on the decay width. Furthermore, we
propose various strategies of a direct search for such CP-violating couplings
by using d... | 9901343v2 |
1999-02-05 | Measurements of electroweak couplings of the tau lepton at L3 | We review the current knowledge of the couplings of the tau lepton to the
electroweak gauge bosons, the W, Z and photon, obtained from the full L3 data
sample at center-of-mass energies near the Z mass. Measurements of the the
effective vector and axial-vector weak neutral couplings of the $\tau$, the
Lorentz structure... | 9902253v1 |
1999-02-16 | Spin Effects in Diffractive $J/Ψ$ Leptoproduction and Structure of Pomeron Coupling | We calculate the cross section and the $A_{ll}$ asymmetry of the diffractive
vector meson leptoproduction for a simple model of the pomeron coupling with
the proton. It is found that the sensitivity of the spin--dependent cross
section of the diffractive $J/\Psi$ production to the pomeron coupling
structure is rather w... | 9902356v2 |
1999-08-31 | A new approach to axial coupling constants in the QCD sum rule | We derive new QCD sum rules for the axial coupling constants by considering
two-point correlation functions of the axial-vector currents in a one nucleon
state. The QCD sum rules tell us that the axial coupling constants are
expressed by nucleon matrix elements of quark and gluon operators which are
related to the sigm... | 9908512v1 |
1999-09-28 | The CP-violating triple gluon interaction in Z -> 4 jets | We analyse CP-violating effects in Z -> 4 jet decays, assuming the presence
of a CP-violating effective triple gluon coupling. We discuss the influence of
this coupling on the decay width. Furthermore, we analyse different CP-odd
observables and propose strategies of a direct search for such a CP-violating
GGG coupling... | 9909527v1 |
2000-02-14 | Anomalous quartic couplings in six-fermion processes at the Linear Collider | The dimension-four genuine anomalous quartic couplings are studied in
processes of six-fermion production via e+e- collisions. Complete tree-level
electroweak calculations are performed including initial-state-radiation and
beamstrahlung. The analysis of final-state distributions can be used to find
kinematical cuts to... | 0002142v1 |
2000-03-07 | Critical couplings for chiral symmetry breaking via instantons | Using an instanton effective action formalism, we compute the critical
coupling for the nonperturbative formation of a dynamical mass via instantons
in non-Abelian gauge theories with N_f massless fermions. Only continuous phase
transitions are considered. For large values of N_f the critical couplings are
found to be ... | 0003059v2 |
2000-11-03 | Solving the BFKL Equation with Running Coupling | We describe a formalism for solving the BFKL equation with a coupling that
runs for momenta above a certain infrared cutoff. By suitably choosing matching
conditions proper account is taken of the fact that the BFKL diffusion implies
that the solution in the infrared (fixed coupling) regime depends upon the
solution in... | 0011047v2 |
2000-11-21 | CP-violating ZZh Coupling at e+e- Linear Colliders | We study the general Higgs-weak boson coupling with CP-violation via the
process e+e- -> f \bar f h. We categorize the signal channels by sub-processes
Zh production and ZZ fusion and construct four CP asymmetries by exploiting
polarized e+e- beams. We find complementarity among the sub-processes and the
asymmetries to... | 0011271v1 |
2000-12-29 | Brane Couplings from Bulk Loops | We compute loop corrections to the effective action of a field theory on a
five-dimensional $S_1/Z_2$ orbifold. We find that the quantum loop effects of
interactions in the bulk produce infinite contributions that require
renormalization by four-dimensional couplings on the orbifold fixed planes.
Thus bulk couplings gi... | 0012379v2 |
2001-01-23 | Testing Higgs Self-Couplings at High-Energy Linear Colliders | In order to verify the Higgs mechanism experimentally, the Higgs
self-couplings have to be probed. These couplings allow the reconstruction of
the characteristic Higgs potential responsible for the electroweak symmetry
breaking. The couplings are accessible in a variety of multiple Higgs
production processes. The theor... | 0101262v1 |
2001-04-09 | Treatment of the QCD coupling in high energy processes | The treatment of the running QCD coupling in evolution equations is
discussed. It is shown that the use of the virtuality of ladder (vertical)
partons as the scale for QCD coupling in every rung of ladder graphs is an
approximation that holds for DIS at large x only. On the contrary, in the small
x region the coupling ... | 0104082v2 |
2001-05-02 | Light Higgs bosons from a strongly interacting Higgs sector | The mass and the decay width of a Higgs boson in the minimal standard model
are evaluated by a variational method in the limit of strong self-coupling
interaction. The non-perturbative technique provides an interpolation scheme
between strong-coupling regime and weak-coupling limit where the standard
perturbative resul... | 0105018v1 |
2001-06-30 | Critical couplings in Crystalline Color superconductivity | Solving the Schwinger-Dyson equations, we analyze the pairing of quarks in
asymmetric quark matter where quarks have different chemical potentials. We
show that in the asymmetric quark matter a crystalline color-superconducting
gap opens when the quark coupling is stronger than a critical value. The
critical coupling i... | 0107003v1 |
2001-07-04 | Yukawa Hierarchy Transfer from Superconformal Sector and Degenerate Sfermion Masses | We propose a new type of supersymmetric models coupled to superconformal
field theories (SCFT's), leading simultaneously to hierarchical Yukawa
couplings and completely degenerate sfermion masses. We consider models with an
extra Abelian gauge symmetry to generate hierarchical structure for couplings
between the SM sec... | 0107030v2 |
2001-11-23 | Determination of the muon Yukawa coupling at high energy e+e- linear colliders | The perspectives for the observation of the rare decay H -> mumu decay and
the determination of the muon Yukawa coupling at a TeV-class and at a multi-TeV
e+e- linear colliders are discussed. The signal for the decay can be obtained
at 0.8 TeV and a first estimate of the coupling derived. A linear collider
operating at... | 0111307v1 |
2002-05-13 | The Infrared Behaviour of the Running Coupling in Landau Gauge QCD | Approximate solutions for the gluon and ghost propagators as well as the
running coupling in Landau gauge Yang-Mills theories are presented. These
propagators obtained from the corresponding Dyson-Schwinger equations are in
remarkable agreement with those of recent lattice calculations. The resulting
running coupling p... | 0205125v1 |
2002-05-15 | The Energy Dependence of the Saturation Momentum | We study BFKL evolution and, in particular, the energy dependence of the
saturation momentum in the presence of saturation boundaries limiting the
region of linear BFKL evolution. In the case of fixed coupling evolution we
confirm the previously found exponential term in $Q_s(Y)$ and determine the
prefactor $Y$ and $\a... | 0205167v1 |
2002-05-21 | Radion Couplings to Bulk Fields in the Randall-Sundrum Model | The radion may be the lightest new state present in the Randall-Sundrum(RS)
model. We examine the couplings of the radion to the Standard Model(SM) fields
in the scenario where they propagate in the bulk and expand into Kaluza-Klein
towers. These couplings are then contrasted with those of the more familiar
case where ... | 0205242v1 |
2002-08-08 | On the QCD coupling behavior in the infrared region | The summary of nonperturbative results for the QCD invariant coupling
bar{alpha}_s obtained by lattice simulations for functional integral and by
solution of approximate Dyson--Schwinger equations reveals a puzzling variety
of IR behavior of bar{alpha}_s(Q^2) even on a qualitative level. This, in turn,
rises a question... | 0208082v1 |
2002-11-06 | Quartic Gauge Boson Couplings and Tree Unitarity in the SU(3)_C X SU(3)_L X U(1)_N Models | The quartic gauge boson couplings in the ${SU(3)}_C \otimes {SU(3)}_L \otimes
{U(1)}_N$ models are presented. We find that the couplings of four {\it
differrent} gauge bosons may have unusual Lorentz structure and the couplings
sastify the tree unitarity requirement at high energy limit. | 0211072v1 |
2002-11-26 | Grand Unification and Time Variation of the Gauge Couplings | Astrophysical indications that the fine structure constant is time dependent
are discussed in the framework of grand unification models. A variation of the
electromagnetic coupling constant could either be generated by a corresponding
time variation of the unified coupling constant or by a time variation of the
unifica... | 0211421v1 |
2003-02-28 | J/psi couplings to charmed resonances and to pi | We present an evaluation of the strong couplings JD^(*)D^(*) and
JD^(*)D^(*)pi by an effective field theory of quarks and mesons. These
couplings are necessary to calculate pi+J/psi --> D^(*)+barD^(*) cross
sections, an important background to the J/psi suppression signal in the
quark-gluon plasma. We write down the ge... | 0302273v3 |
2003-06-17 | Vector Boson Fusion and Quartic Boson Couplings | One of the goals of the upcoming experiments at the LHC is the exploration of
electroweak symmetry breaking in all aspects. In particular, the self-couplings
of the vector gauge bosons are completely specified in the Standard Model, as
are the couplings of the Higgs boson to the vector bosons once the Higgs mass
is kno... | 0306160v1 |
2003-10-01 | The trilinear neutral Higgs self-couplings in the MSSM. Complete one-loop analysis | The Higgs boson effective self-couplings $\lambda_{hhh}$ and $\lambda_{HHH}$
are calculated in the framework of the Minimal Supersymmetric Standard Model
(MSSM) for the complete set of one-loop diagrams with one of the Higgs bosons
off-shell. The comparison with previous results, where only the leading
correction terms... | 0310018v1 |
2003-12-27 | Flavor Structure of Scherk-Schwarz Supersymmetry Breaking for Quasi-Localized Matter Field | We discuss the flavor structure of soft supersymmetry breaking parameters in
5-dimensional orbifold field theories in which N=1 supersymmetry is broken by
the Scherk-Schwarz boundary condition and hierarchical 4-dimensional Yukawa
couplings are obtained by quasi-localizing the matter fields in extra
dimension. In such ... | 0312357v1 |
2004-10-05 | The QCD analytic running coupling and chiral symmetry breaking | We study the dependence on the pion mass of the QCD effective charge by
employing the dispersion relations for the Adler D function. This new massive
analytic running coupling is compared to the effective coupling saturated by
the dynamically generated gluon mass. A qualitative picture of the possible
impact of the for... | 0410072v1 |
2004-11-03 | Analysis of SO(2N) Couplings of Spinor and Tensor Representations in $SU(N)\times U(1)$ Invariant Forms | A review is given of a recently developed technique for the analysis of
SO(2N) invariant couplings which allows a full exhibition of the SU(N)
invariant content of couplings involving the SO(2N) semi-spinors $|\Psi_{\pm}>$
with chiralilty $\pm$ and tensor representations. We discuss the Basic Theorem
used in the analys... | 0411054v1 |
2004-11-04 | On an Intensity-Ratio Equivalence for Two Top-Quark Decay Couplings | For the t --> W b decay mode, an intensity-ratio equivalence for two distinct
Lorentz-invariant couplings is shown to be a consequence of symmetries of
tWb-transformations. Three explicit tWb-transformations connect the four
standard model's (SM) helicity amplitudes and the amplitudes in the case of an
additional chira... | 0411072v1 |
2005-04-04 | Weak-coupling techniques for the thermodynamics of the quark-gluon plasma | We describe some of the recent progress in the calculation of thermodynamic
quantities in QCD at high temperatures and densities by weak-coupling
techniques and extrapolation to realistic coupling strength. We argue that a
(mostly) weakly coupled quark-gluon plasma at temperatures only a few times the
transition temper... | 0504023v3 |
2005-10-28 | Non-perturbative renormalization of Phi-derivable approximations in theories with multiple fields | We provide a renormalization procedure for Phi-derivable approximations in
theories coupling different types of fields. We illustrate our approach on a
scalar phi^4 theory coupled to fermions via a Yukawa-like interaction. The
non-perturbative renormalization amounts to fixing the scalar coupling via a
set of nested Be... | 0510380v2 |
2005-11-01 | Unitary Structure of the QCD Sum Rules and KYN and KYΞCouplings | New relations between QCD Borel sum rules for strong coupling constants of
K-mesons to baryons are derived. It is shown that starting from the sum rule
for the coupling constants $g_{\pi\Sigma\Sigma}$ and $g_{\pi\Sigma\Lambda}$ it
is straightforward to obtain corresponding sum rules for the $g_{K Y N}$, $g_{K
Y \Xi}$ c... | 0511007v1 |
2006-02-03 | Higgs Boson Mass From Orbifold GUTs | We consider a class of seven-dimensional N=1 supersymmetric orbifold GUTs in
which the Standard Model (SM) gauge couplings and one of the Yukawa couplings
(top quark, bottom quark or tau lepton) are unified, without low energy
supersymmetry, at M_{GUT} \simeq 4 \times 10^{16} GeV. With gauge-top quark
Yukawa coupling u... | 0602040v2 |
2006-02-17 | Gauge Coupling Unification, SUSY Scale and Strong Coupling Running | The apparent unification of gauge couplings around 10^16 GeV is one of the
strong arguments in favor of Supersymmetric extensions of the Standard Model
(SM). In this contribution two new analyses of the gauge coupling running, the
latter using in contrast to previous studies not data at the Z peak but at LEP2
energies,... | 0602168v1 |
2006-09-07 | Anomalous Higgs boson couplings in vector boson fusion at the CERN LHC | Deviations from SM expectations in the Higgs sector can be parameterized by
an effective Lagrangian. The corresponding anomalous couplings have been
implemented in a Monte Carlo program for Higgs production in vector boson
fusion, at NLO QCD accuracy. It allows to study anomalous coupling effects for
production and dec... | 0609075v2 |
2006-09-19 | Testing the SUSY-QCD Yukawa coupling in a combined LHC/ILC analysis | In order to establish supersymmetry (SUSY) at future colliders, the identity
of gauge couplings and the corresponding Yukawa couplings between gauginos,
sfermions and fermions needs to be verified. Here a first phenomenological
study for determining the Yukawa coupling of the SUSY-QCD sector is presented,
using a metho... | 0609180v1 |
2007-01-25 | Couplings and spectra in modular inflation | We analyze how the spectrum of perturbations produced in a multi-component
modular inflation model proposed by Kadota and Stewart depends on couplings
between the two moduli. Although some simple direct couplings give essentially
the same results as the original model, $dn/d\ln k \propto n-1$, simple
indirect couplings... | 0701213v2 |
1992-01-29 | Interaction of Tachyons and Discrete States in c=1 2-D Quantum Gravity | The two-dimensional (2-D) quantum gravity coupled to the conformal matter
with $c=1$ is studied. We obtain all the three point couplings involving
tachyons and/or discrete states via operator product expansion. We find that
cocycle factors are necessary and construct them explicitly. We obtain an
effective action for t... | 9201066v2 |
1992-03-25 | Moduli Corrections to Gravitational Couplings from String loops | We study moduli dependent threshold corrections to gravitational couplings in
the case of the heterotic string compactified on a symmetric orbifold, for
untwisted moduli, extending previous analysis on gauge couplings. Like in the
gauge case, the contribution comes entirely from the spacetime $N=2$ sector. As
a byprodu... | 9203071v1 |
1992-04-07 | Matter Coupling and Spontaneous Symmetry Breaking in Topological Gravity | Matter is coupled to three-dimensional gravity such that the topological
phase is allowed and the (anti-) de Sitter or Poincar\'e symmetry remains
intact. Spontaneous symmetry breaking to the Lorentz group occurs if a scalar
field is included. This Higgs field can then be used to couple matter so that
the familiar form... | 9204015v1 |
1992-12-11 | Exactly Marginal Operators and Running Coupling Constants in 2D Gravity | The Liouville action for two--dimensional quantum gravity coupled to
interacting matter contains terms that have not been considered previously.
They are crucial for understanding the renormalization group flow and can be
observed in recent matrix model results for the phase diagram of the
Sine--Gordon model coupled to... | 9212075v3 |
1993-01-18 | Berenstein-Zelevinsky triangles, elementary couplings and fusion rules | We present a general scheme for describing su(N)_k fusion rules in terms of
elementary couplings, using Berenstein-Zelevinsky triangles. A fusion coupling
is characterized by its corresponding tensor product coupling (i.e. its
Berenstein-Zelevinsky triangle) and the threshold level at which it first
appears. We show th... | 9301075v1 |
1993-11-02 | Mirror Symmetry for Hypersurfaces in Weighted Projective Space and Topological Couplings | By means of toric geometry we study hypersurfaces in weighted projective
space of dimension four. In particular we compute for a given manifold its
intrinsic topological coupling. We find that the result agrees with the
calculation of the corresponding coupling on the mirror model in the large
complex structure limit. | 9311014v2 |
1994-01-11 | A Study of Fermions Coupled to Gauge and Gravitational Fields on a Cylinder | Fermions on a cylinder coupled to gravity and gauge fields are examined by
studying the geometric action associated with the symmetries of such a system.
The gauge coupling constant is shown to be constrained and the effect of
gravity on the masses is discussed. Furthermore, we introduce a new
gravitational theory whic... | 9401039v2 |
1994-08-19 | Conformal Invariance of Interacting WZNW Models | We consider two level $k$ WZNW models coupled to each other through a
generalized Thirring-like current-current interaction. It is shown that in the
large $k$ limit, this interacting system can be presented as a two-parameter
perturbation around a nonunitary WZNW model. The perturbation operators are the
sigma model ki... | 9408112v1 |
1994-09-07 | Unification of the Soluble Two-dimensional vector coupling models | The general theory of a massless fermion coupled to a massive vector meson in
two dimensions is formulated and solved to obtain the complete set of Green's
functions. Both vector and axial vector couplings are included. In addition to
the boson mass and the two coupling constants, a coefficient which denotes a
particul... | 9409038v1 |
1994-10-13 | Towards a Strong Coupling Liouville Gravity | A possibility of strong coupling quantum Liouville gravity is investigated
via infinite dimensional representations of $\qslc$ with $q$ at a root of
unity. It is explicitly shown that vertex operator in this model can be written
by a tensor product of a vertex operator of the classical Liouville theory and
that of weak... | 9410088v1 |
1995-03-21 | Double expansion in asymptotically free theories | I propose an approximation scheme for asymptotically free field theories
combining both weak coupling and strong coupling series. The weak coupling
expansion is used to integrate the high frequency modes and the resulting low
energy effective theory is solved using the strong coupling expansion. In some
models there ex... | 9503128v1 |
1995-04-01 | STRINGY EVIDENCE FOR D=11 STRUCTURE IN STRONGLY COUPLED TYPE II-A SUPERSTRING | Witten proposed that the low energy physics of strongly coupled D=10 type-IIA
superstring may be described by D=11 supergravity. To explore the stringy
aspects of the underlying theory we examine the stringy massive states. We
propose a systematic formula for identifying non-perturbative states in D=10
type-IIA superst... | 9503228v1 |
1995-05-23 | Dilaton Gravity Coupled to a Nonlinear Sigma Model in $2+ε$ Dimensions | Quantum theory of dilaton gravity coupled to a nonlinear sigma model with a
maximally symmetric target space is studied in $2+\epsilon$ dimensions. The
ultraviolet stable fixed point for the curvature of the nonlinear sigma model
demands a new fixed point theory for the dilaton coupling function. The fixed
point of the... | 9505132v1 |
1995-06-07 | THE NEW PHYSICS OF STRONGLY COUPLED 2D GRAVITY | The strong coupling physics of two dimensional gravity at $C=7$, $13$, $19$
is summarized. It is based on a new set of local fields which do not preserve
chirality. Thus this quantum number becomes ``deconfined'' in the strongly
coupled regime. This new set leads to a novel definition of the area elements,
and hence to... | 9506040v1 |
1995-06-19 | Running surface couplings | We discuss the renormalization group improved effective action and running
surface couplings in curved spacetime with boundary. Using scalar
self-interacting theory as an example, we study the influence of the boundary
effects to effective equations of motion in spherical cap and the relevance of
surface running coupli... | 9506117v1 |
1995-09-21 | Strong coupling regime in two-dimensional large-N scalar quantum chromodynamics | Two-dimensional large-$N$ quantum chromodynamics with scalar quarks is
considered with particular emphasis on its strong coupling regime which has not
been studied so far. Techniques necessary to deal with the infinitely
oscillatory bound state wave functions in the strong coupling regime are
developed. I derive an est... | 9509117v2 |
1995-11-01 | Reduction of Coupling Parameters | The general theory of the reduction in the number of coupling parameters is
discussed. The method involves renormalization group invariant relations
between couplings. It is more general than the imposition of symmetries. There
are reduced theories with no known symmetry. The reduction scheme is finding
many applicatio... | 9511006v1 |
1996-04-12 | Prepotentials of N=2 SU(2) Yang-Mills theories coupled with massive matter multiplets | We discuss N=2 SU(2) Yang-Mills gauge theories coupled with N_f (=2,3)
massive hypermultiplets in the weak coupling limit. We determine the exact
massive prepotentials and the monodromy matrices around the weak coupling
limit. We also study that the double scaling limit of these massive theories
and find that the massi... | 9604059v2 |
1996-10-07 | Is the String Coupling Constant invariant under T-duality? | It is well known that under T-duality the sigma model dilaton (which is
normally thought to be related to the string coupling constant through the
simple formula $\kappa = exp <\phi >$), undergoes an additive shift. On the
other hand, Kugo and Zwiebach, using a simplified form of string field theory,
claim that the str... | 9610032v1 |
1997-05-02 | Exact Renormalization Group and Running Newtonian Coupling in Higher Derivative Gravity | We discuss exact renormalization group (RG) in $R^2$-gravity using effective
average action formalism. The truncated evolution equation for such a theory on
De Sitter background leads to the system of nonperturbative RG equations for
cosmological and gravitational coupling constants. Approximate solution of
these RG eq... | 9705008v1 |
1997-07-17 | Integrability of Coupled Conformal Field Theories | The massive phase of two-layer integrable systems is studied by means of RSOS
restrictions of affine Toda theories. A general classification of all possible
integrable perturbations of coupled minimal models is pursued by an analysis of
the (extended) Dynkin diagrams. The models considered in most detail are
coupled mi... | 9707159v2 |
1998-02-03 | A Solvable Model of Two-Dimensional Dilaton-Gravity Coupled to a Massless Scalar Field | We present a solvable model of two-dimensional dilaton-gravity coupled to a
massless scalar field. We locally integrate the field equations and briefly
discuss the properties of the solutions. For a particular choice of the
coupling between the dilaton and the scalar field the model can be interpreted
as the two-dimens... | 9802013v1 |
1998-02-10 | Vortex Solutions of Four-fermion Theory coupled to a Yang-Mills-Chern-Simons Gauge Field | We have constructed a four-fermion theory coupled to a
Yang-Mills-Chern-Simons gauge field which admits static multi-vortex solutions.
This is achieved through the introduction of an anomalous magnetic interation
term in addition to the usual minimal coupling, and the appropriate choice of
the fermion quartic coupling ... | 9802062v2 |
1998-03-18 | Quantum modified moduli spaces and field dependent gauge couplings | In this paper we discuss quantum modified moduli spaces in supergravity. We
examine a model suggested by Izawa and Yanagida and by Intriligator and Thomas
that breaks global supersymmetry by a quantum deformation of the classical
moduli space. We determine the minimum of the supergravity potential when the
gauge coupli... | 9803143v1 |
1998-03-20 | Axial and gauge anomalies in a theory with one and two-form gauge fields | We study the problem of axial and gauge anomalies in a reducible theory
involving vector and tensor gauge fields coupled in a topological way. We
consider that vector and axial fermionic currents couple with the tensor field
in the same topological manner as the vector gauge one. This kind of coupling
leads to an anoma... | 9803172v1 |
1998-09-01 | Cosmic Strings in the Abelian Higgs Model with Conformal Coupling to Gravity | Cosmic string solutions of the abelian Higgs model with conformal coupling to
gravity are shown to exist. The main characteristics of the solutions are
presented and the differences with respect to the minimally coupled case are
studied. An important difference is the absence of Bogomolnyi cosmic string
solutions for c... | 9809002v2 |
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