Possibility of weakly charged nonlinear solitary dust clouds near the continuum threshold of dust population in a quasi-neutral dusty plasma

Pramana ◽  
1998 ◽  
Vol 51 (6) ◽  
pp. 757-771 ◽  
Author(s):  
S. K. Baishya ◽  
Joyanti Chutia ◽  
M. K. Kalita ◽  
G. C. Das ◽  
C. B. Dwivedi
2018 ◽  
Vol 172 ◽  
pp. 04005 ◽  
Author(s):  
Juan Pablo Carlomagno ◽  
Marcelo Loewe

We study the relation between two order parameters for deconfinement, normally employed in the literature: the continuum threshold s0, in the context of QCD Sum Rules, and the trace of the Polyakov loop ϕ in the framework of a nonlocal SU(2) chiral quark model. We establish a bridge between both order parameters at finite temperature T and baryonic chemical potential μ. In our analysis, we also include the the chiral quark condensate, the order parameter for the chiral symmetry restoration. We found that s0 and ϕ provide us with the same information for the deconfinement transition, both for the zero and finite chemical potential cases. At zero density, the critical temperatures for both quantities coincide exactly. This part of the analysis has been reinforced by the discussion of the corresponding susceptibilities and the static quark entropy behavior. At finite μ both order parameters provide evidence for the appearance of a quarkyonic phase.


2016 ◽  
Vol 31 (37) ◽  
pp. 1630041 ◽  
Author(s):  
Jens Erler ◽  
Pere Masjuan ◽  
Hubert Spiesberger

In this paper, we present preliminary results of the determination of the charm quark mass [Formula: see text] from QCD sum rules of moments of the vector current correlator calculated in perturbative QCD at [Formula: see text]. Self-consistency between two different sum rules allow to determine the continuum contribution to the moments without requiring experimental input, except for the charm resonances below the continuum threshold. The existing experimental data from the continuum region is used, then, to confront the theoretical determination and reassess the theoretic uncertainty.


1992 ◽  
Vol 9 ◽  
pp. 93-100
Author(s):  
Farhad Yusef-Zadeh

AbstractThe dynamic subject of the Galactic center is driven mostly by high-resolution imaging both in the continuum and in the spectral line modes in a number of wavelength regimes. An attempt has been made to give a short overview of recent observations in this region, as follows: 1) Unusual characteristics of the population of molecular and dust clouds within the inner few hundred pc of the Galactic center. 2) Large-scale magnetic structures within the inner 100 pc of the Galactic center and the possible evidence for their poloidal configurations -unlike that seen in the disk of the Galaxy. 3) Stellar kinematics in the bulge and the possible evidence for a massive central source at the dynamical center and its examination as a gravitational lens. 4) Morphological and kinematic evidence for the Galactic center wind interacting with stellar wind associated IRS7, a mass-losing supergiant lying one light year away in projection from the Galactic center.


2009 ◽  
Vol 24 (35n37) ◽  
pp. 2848-2857 ◽  
Author(s):  
A. P. BAKULEV ◽  
A. V. PIMIKOV ◽  
N. G. STEFANIS

We discuss the QCD sum-rule approach for the spacelike electromagnetic pion form factor in the O(αs) approximation. We show that the nonlocality of the condensates is a key point to include nonperturbative contributions to the pion form factor. We compare our results with the Local-Duality predictions and show that the continuum threshold s0(Q2) parameter is highly underestimated in the Local-Duality approach at Q2 ≳ 2 GeV 2. Using our fit for this parameter, [Formula: see text] and applying the fractional analytic perturbation theory, we estimate with an accuracy of the order of 1% the [Formula: see text] contribution to the pion's form factor.


2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Jarah Evslin

Abstract The 𝜙4 double-well theory admits a kink solution, whose rich phenomenology is strongly affected by the existence of a single bound excitation called the shape mode. We find that the leading quantum correction to the energy needed to excite the shape mode is −0.115567λ/M in terms of the coupling λ/4 and the meson mass M evaluated at the minimum of the potential. On the other hand, the correction to the continuum threshold is −0.433λ/M. A naive extrapolation to finite coupling then suggests that the shape mode melts into the continuum at the modest coupling of λ/4 ∼ 0.106M2, where the ℤ2 symmetry is still broken.


1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.


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