407 research outputs found
Two dimensional QCD and abelian bosonization
A bosonized action, that reproduces the structure of the 't Hooft equation
for in the large- limit, up to regularization dependent terms, is
derived.Comment: paper revised, several signs and coefficients corrected. A comment on
regularization dependence and several references adde
Exact beta function from the holographic loop equation of large-N QCD_4
We construct and study a previously defined quantum holographic effective
action whose critical equation implies the holographic loop equation of large-N
QCD_4 for planar self-avoiding loops in a certain regularization scheme. We
extract from the effective action the exact beta function in the given scheme.
For the Wilsonean coupling constant the beta function is exacly one loop and
the first coefficient agrees with its value in perturbation theory. For the
canonical coupling constant the exact beta function has a NSVZ form and the
first two coefficients agree with their value in perturbation theory.Comment: 42 pages, latex. The exponent of the Vandermonde determinant in the
quantum effective action has been changed, because it has been employed a
holomorphic rather than a hermitean resolution of identity in the functional
integral. Beta function unchanged. New explanations and references added,
typos correcte
Phase structure of QCD for general number of flavors
We investigate and elucidate the phase structure of QCD for general number of
flavors with Wilson quarks, varying from 2 up to 300. Based on
numerical results combined with the result of the perturbation theory we
propose the following picture: When , there is only a trivial fixed
point and therefore the theory in the continuum limit is trivial. On the other
hand, when , there is a non-trivial fixed point and therefore
the theory is non-trivial with anomalous dimensions, however, without quark
confinement. Theories which satisfy both quark confinement and spontaneous
chiral symmetry breaking in the continuum limit exist only for . We
also discuss the structure of the deconfining phase at finite temperatures for
the small number of flavors such as and 3, through a systematic study
of it for general number of flavors.Comment: LaTeX, 7 pages, 10 PS figures, Talk presented at LATTICE96(poster)
and LATTICE96(finite temperature
Finite Temperature QCD with Wilson Quarks: A Study with a Renormalization Group Improved Gauge Action
Finite temperature transition in lattice QCD with degenerate Wilson quarks is
investigated on an lattice, using a renormalization group improved
gauge action. We find the following for the case:
1) The transition is smooth for a wide range of the quark mass.
2) The chiral transition is continuous.
3) The chiral condensation well satisfies a scaling relation with the
critical exponents of the 3 dimensional spin model. For , we find
that the chiral transition is of first order.Comment: 4 pages (6 figures), Postscript file, Contribution to Lattice 95
proceeding
The Light Quark Masses with the Wilson Quark Action using Chiral Ward Identities
We present results for the light quark masses for the Wilson quark action
obtained with the PCAC relation for the one-link extended axial vector current
in quenched QCD at . This method leads to a remarkable
improvement of scaling behavior of the light quark masses compared to the
conventional method. We obtain MeV for the averaged up and
down quark mass and MeV for the strange quark mass in the
{\barMS} scheme at GeV.Comment: 3 pages, latex source-file, 2 figures as epsf-file, uses espcrc2.sty.
Poster presented at Lattice 97: 15th International Symposium on Lattice Field
Theory, Edinburgh, Scotland, 22-26 Jul 199
Right-Wing Authoritarianism and Antipathy Toward Immigrants and Sexual Minorities in the Early Days of the Coronavirus Pandemic in Italy
Theory and research in social, evolutionary, and political psychology indicates that subjective feelings of threat and exposure to objectively threatening circumstances—including pandemic diseases—may contribute to increased affinities for political conservatism, right-wing authoritarianism, and prejudice against out-group members. We investigated these possibilities in the context of Italy, which was the first Western country to be severely affected by the spread of COVID-19. Early on in the pandemic, from March 3–8, 2020, we surveyed 757 Italian adults ranging in age from 18 to 78 years. Results revealed that antipathy toward immigrants and sexual minorities was predicted by (male) sex, COVID-19 anxiety, RWA, and political distrust. Furthermore, COVID-19 anxiety magnified the effect of RWA on disliking of immigrants and sexual minorities (but not obese or disabled people). Contrary to prediction, political trust failed to attenuate the effects of COVID-19 anxiety or RWA on out-group antipathy. Implications for the theories of right-wing authoritarianism and political ideology as motivated social cognition, as well as the state of contemporary Italian politics are discussed
Finite-Temperature Phase Structure of Lattice QCD with Wilson Quark Action
The long-standing issue of the nature of the critical line of lattice QCD
with the Wilson quark action at finite-temperatures, defined to be the line of
vanishing pion screening mass, and its relation to the line of
finite-temperature chiral tansition is examined. Analytical and numerical
evidence are presented that the critical line forms a cusp at a finite gauge
coupling, and the line of chiral transition runs past the tip of the cusp
without touching the critical line. Implications on the continuum limit and the
flavor dependence of chiral transition are discussed.Comment: 13 pages(4 figures), latex (epsf style-file needed), one sentence in
abstract missed in transmission supplied and a few minor modifications in the
text mad
Finite-temperature chiral transitions in QCD with the Wilson quark action
We investigate the finite-temperature phase structure and the scaling of the
chiral condensate in lattice QCD with two degenerate light quarks, using a
renormalization group improved gauge action and the Wilson quark action. We
obtain a phase diagram which is consistent with that from the parity-flavor
breaking scenario. The scaling relation for the chiral condensate assuming the
critical exponents and the scaling function of the three dimensional O(4) model
is remarkably satisfied for a wide range of parameters. This indicates that the
chiral transition in two flavor QCD is of second order in the continuum limit.Comment: LaTeX, 3 pages, 4 EPS figures, Talk presented at LATTICE97 (finite
temperature
Advances in the Determination of Quark Masses
Significant progress has been made in the determination of the light quark
masses, using both lattice QCD and sum rule methods, in the last year. We
discuss the different methods and review the status of current results.
Finally, we review the calculations of bottom and charm quark masses.Comment: 14 pages. Package submitted in uufiles format: unpack and latex
paper.tex. Plenary talk presented at LATTICE97. This version fixes typos in
the proceedings version and includes additional dat
TUNING TO SUPERSYMMETRY IN THE SU(2) ADJOINT HIGGS-YUKAWA MODEL
The supersymmetric continuum limit is investigated in the SU(2) adjoint
Higgs-Yukawa model using lattice perturbation theory. In the one-loop
renormalization group equations a non-trivial infrared fixed point of coupling
ratios is found. The phase structure at weak couplings is determined by a
numerical study of the one-loop effective potential.Comment: 32 pages, latex, 7 figures
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