The phenomenon of the almost linear growth of the square root of spatial string tension
and of the Debye mass
was found both in lattice and in theory, based on the Field Correlator Method (FCM). In ...the latter the string tension (both spatial and colorelectric) is expressed as an integral of the two gluon Green’s function calculated with the same string tension:
. This relation allows to check the self-consistency of the theory and at high
it allows also to calculate
and hence
. We calculate below in the paper the corresponding coefficients
and
numerically in the FCM method and compare the results with lattice data finding a good agreement. This justifies the use of the FCM in the space-like region and in high-
thermodynamics without extra parameters.
Nucleon form factors play an especially important role in studying the dynamics of nucleons and explicit structure of the wave functions at arbitrary nucleon velocity. The purpose of the paper is to ...explain theoretically all four nucleon form factors measured experimentally in the cross section measurements (by the Rosenbluth method), yielding almost equal normalized form factors
G
E
p
,
G
M
p
,
G
M
n
), as well as in the polarization transfer experiments, where a strongly decreasing proton electric form factor has been discovered. It is shown, using relativistic hyperspherical formalism, that the nucleon wave functions in the lowest (hypercentral) approximation provide almost equal normalized form factors as seen in the Rosenbluth cross sections, but in the higher components they contain a large admixture of the quark orbital momenta, which strongly decreases
G
E
p
and this effect is possibly detected in the polarization transfer method (not seen in the classical cross section experiments). Moreover, the same admixture of the higher components explains the small positive form factor
G
E
n
, which is zero in the hypercentral approximation. The resulting form factors,
G
M
p
(
Q
)
,
G
E
p
(
Q
)
,
G
M
n
(
Q
)
are calculated up to
Q
2
≈
10
GeV
2
, using the the Lorentz contracted nucleon wave functions and shown to be in reasonable agreement with experimental data.
The basic form of the quark condensate for arbitrary values of the quark mass, external magnetic field and temperature, is derived using the field equations with account of confinement. The resulting ...expression of the chiral condensate is shown to be proportional to square of the singlet
ground state wave function at origin,
. For light quarks without magnetic field the condensates are proportional to
(
is the string tension). Numerical results are presented in 5 Tables and shown to be in good agreement with the lattice data, both for nonzero magnetic field
and temperature
in the range
MeV,
GeV
.
The thermodynamics of quarks and gluons strongly depends on the vacuum colormagnetic field, which grows with the temperature
T
, so that spatial string tension
σ
s
=
const
g
4
(
T
)
T
2
. We ...investigate below what happens when one imposes in addition constant magnetic field and discover remarkable structure of the resulting thermodynamic potential.
The Fundamental Scale of QCD Simonov, Yu. A.
Physics of atomic nuclei,
11/2021, Letnik:
84, Številka:
6
Journal Article
Recenzirano
Odprti dostop
There are several scales in the QCD as the theory of strong interaction: the vacuum gluonic condensate (as the divergence of the dilatation current), the nucleon mass as the basic mass scale in our ...universe, which is connected to the string tension
, and the perturbative QCD scale
, which defines the scale of the renormalized perturbative expansions. In this paper we connect all these scales to the vacuum condensate, using the field correlator method, where the string tension is expressed in terms of nonlocal field correlators, which are connected to the local condensates, while the perturbative
is connected to
in the framework of the Background Perturbation Theory (BPT). We also demonstrate how the IR singularities and IR renormalons disappear in BPT making the resulting theory internally consistent.
The behaviour of spatial string tension
σ
s
(
T
)
as a function of the temperature
T
is found in the framework of the Field Correlator Method (FCM). Here the string tension is calculated using the ...gluelump Green’s function, where gluons in the gluelump are interacting via the same spatial string tension. The resulting T-dependence was obtained without extra parameters in the region
T
c
<
T
<
5
T
c
using the formalism of elliptic functions
θ
3
, demonstrating good agreement with available lattice data.
The effect of structural parameters on the strength and crack resistance of maraging steels under single loading has been investigated. It has been found that the increase in strength due to ...dispersion hardening with intermetallic compounds in the steels studied is determined by the titanium content and the presence of cobalt. It has been shown that the change in crack resistance under single loading with increasing tempering temperature has a complicated character. It was found that, unlike the dynamic crack resistance, the minimum level of the static crack resistance characteristics of the steels studied corresponds to the maximum strength. Possible reasons for such a change in static and dynamic crack resistance characteristics are discussed.
The speed of sound Cs in the SU(3) and (2+1) QCD is calculated within the field correlator method using the nonperturbative color magnetic confinement and Polyakov loop interaction in the deconfined ...region.The resulting Cs displays a discontinuity at T=Tc in the SU(3) case. It is shown numerically and analytically that Cs2 never exceeds 13 both for SU(3) and (2+1) QCD for vanishing chemical potential. A good agreement is found of our numerical results with the corresponding lattice data.
Properties of the quark-gluon plasma (QGP) in the presence of the baryon chemical potential μB are studied using the field correlator method (FCM). The nonperturbative FCM dynamics includes the ...Polyakov line, computed via color-electric string tension σE(T), and the quark and gluon Debye masses, defined by the color-magnetic string tension σH(T). The resulting QGP thermodynamics at μB ≤ 400 MeV is in a good agreement with the available lattice data; neither the pressure nor the sound velocity shows any sign of a critical behavior in this region.
Hadron form factors are calculated using the Lorentz-contracted wave functions, determined in the arbitrary dynamical scheme with the instantaneous interaction. It is shown that the large
asymptotics ...of the form factors is defined by the contraction coefficient
, where
is the meson mass, and weakly depends on the interaction used. The resulting form factors
and
are obtained in good agreement with the lattice and experimental data. Important consequences for the dynamics of hadron decays and scattering are shortly discussed.
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