9,027 research outputs found
QCD Sum-Rule Bounds on the Light Quark Masses
QCD sum-rules are related to an integral of a hadronic spectral function, and
hence must satisfy integral inequalities which follow from positivity of the
spectral function. Development of these Holder inequalities and their
application to the Laplace sum-rule for pions lead to a lower bound on the
average of the non-strange 2 GeV light-quark masses in the MS-bar scheme.Comment: latex2e, 8 pages. Write-up of talk presented at MRST 200
Hoelder Inequalities and QCD Sum-Rule Bounds on the Masses of Light Quarks
QCD Laplace Sum-Rules must satisfy a fundamental Hoelder inequality if they
are to consistently represent an integrated hadronic spectral function. The
Laplace sum-rules of pion currents is shown to violate this inequality unless
the and quark masses are sufficiently large, placing a lower bound on
, the SU(2)-invariant combination of the light-quark masses.Comment: 3 pages, latex, write-up of talk presented at DPF 200
Trailing Edge Unification via an Intermediate Pati-Salam Group
We demonstrate to two-loop order that an intermediate symmetrically embedded
Pati-Salam level of symmetry is all that
is necessary to accommodate empirical values of
and within a grand unification context but with a high
(10^{14} GeV) intermediate mass scale and with a concomitant higher GUT scale.Comment: 7 pages, 4 embedded eps figur
Analysis of Exotic Hybrid eta pion, eta-prime pion Decays
Investigations of the mass and decays of the exotic hybrid are reviewed,
including calculation of the pion1 to eta pion, eta-prime pion decay widths
within the QCD sum rules technique. In this calculation, the recently-proposed
eta, eta-prime quark mixing scheme is employed. The results indicate that the
decay width Gamma(pion1 to eta pion) around 250 MeV is large compared with the
decay width Gamma(pion1 to eta-prime pion) around 20 MeV. Inspired by these
results, some phenomenological approaches are suggested to gain an
understanding of the underlying mechanism of eta pion and eta-prime pion hybrid
decays.Comment: 4 pages, talk presented at the 10th International Symposium on
Meson-Nucleon Physics and the Structure of the Nucleon(MENU2004), Beijing,
China, August 29 to September 4, 200
Gaussian Sum-Rule Analysis of Scalar Gluonium and Quark Mesons
Gaussian sum-rules, which are related to a two-parameter Gaussian-weighted
integral of a hadronic spectral function, are able to examine the possibility
that more than one resonance makes a significant contribution to the spectral
function. The Gaussian sum-rules, including instanton effects, for scalar
gluonic and non-strange scalar quark currents clearly indicate a distribution
of the resonance strength in their respective spectral functions. Furthermore,
analysis of a two narrow resonance model leads to excellent agreement between
theory and phenomenology in both channels. The scalar quark and gluonic
sum-rules are remarkably consistent in their prediction of masses of
approximately 1.0 GeV and 1.4 GeV within this model. Such a similarity would be
expected from hadronic states which are mixtures of gluonium and quark mesons.Comment: latex2e using amsmath, 11 pages, 4 eps figures embedded in latex
file. Write-up of presentation for the 2003 SUNY IT (Utica) workshop on
scalar meson
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