32 research outputs found
Mass spectra in SQCD with and problems with S-confinement
The low energy mass spectra of the direct standard
SQCD theory and its N. Seiberg's dual variant [1], considered as
{\it two independent theories}, are calculated in sections 2 and 3. It is shown
that these two mass spectra are parametrically different, both for equal or
unequal quark masses.
Therefore, the proposal by N. Seiberg [1] of his dual theory of
mesons and baryons as the low energy form
of the direct theory is erroneous (and similarly for the case ).
In [17] the very special (not supersymmetric) lattice QCD theory
with scalar non-standard "quarks"\, was considered by E. Fradkin and
S.H. Shenker. The conclusion of [17] was that the transition between the
confinement and higgs regimes in this theory is the analytic crossover, not the
non-analytic phase transition. And although the theory considered in [17] was
very specific, the experience shows that up to now there is a widely spread
opinion that this conclusion has general applicability: both to lattice and
continuum theories, and both to not supersymmetric and supersymmetric ones.
This model used in [17] is criticized in section 5 of this paper as
incompatible with the standard QCD theory with scalar
quarks with all their physical degrees of freedom. Besides, the arguments
presented in [2] by K. Intriligator and N. Seiberg for the standard direct
, SQCD theory in support of conclusions
[17] about crossover are criticized as erroneous.Comment: 18 pages, no figure
Phase transitions between confinement and higgs phases in SQCD with quark flavors
Considered is supersymmetric QCD (SQCD) with equal mass quark flavors in the fundamental representation.
Using a number of independent arguments for different variants of transition
between the confinement and higgs regimes, it is shown that transitions between
these regimes are not crossovers but the phase transitions.
These are counterexamples to a widely spread opinion, originating from the
paper of E. Fradkin and S.H. Shenker [10], about absence of the phase
transition between the confinement and higgs phases.Comment: 10 pages, title and abstract changed, text expanded, argumentation
strengthened, results unchange
Mass spectra in SQCD with additional colorless fields and problems with Seiberg's duality
Considered is the direct SQCD-like -theory with
colors and flavors of light quarks .
Besides, it includes additional colorless but flavored fields
with the large mass parameter ,
interacting with quarks through the Yukawa coupling. In parallel, is considered
its Seiberg's dual variant, i.e. the -theory with dual
colors, flavors of dual quarks and
elementary mion fields .
In considered here vacua, the quarks of both theories are in the conformal
regimes at scales . The mass spectra are calculated in sections
4 and 5. It is shown that they are different in the direct and dual theories,
in disagreement with the Seiberg hypothesis about equivalence of two such
theories.
Besides it is shown in the direct theory that a qualitatively new phenomenon
takes place: the seemingly heavy fields `return back' and there appear
two additional generations of light -particles with small masses
.
In Conclusions also presented comparison of mass spectra of these two
theories for such values of parameters when the direct theory is in the very
strong coupling regime, while the dual one is in the weak coupling IR-free
logarithmic regime. It is shown that mass spectra of these two theories are
parametrically different in this case.Comment: 16 pages. Small improvements in the text, typos corrected, reference
added. Talk given at Session of Nucl.Phys. section of RAS, Novosibirsk,
Russia, 10-12 March 202
gamma+gamma --> pi+pi, K+K : leading term QCD vs handbag model
The "handbag" model was proposed as an alternative, at the present day
energies, to the leading term QCD predictions for some hard exclusive
processes. The recent precise data from the Belle Collaboration on the large
angle cross sections allow a check of these two
approaches to be performed. It is shown that the handbag model fails to
describe the data from Belle, while the leading term QCD predictions are in
reasonable agreement with these dataComment: 12 pages, 4 figures, v4: reference added, small improvements in the
tex