scholarly journals Highly excited pure gauge SU(3) flux tubes

2022 ◽  
Vol 258 ◽  
pp. 10001
Author(s):  
Pedro Bicudo ◽  
Nuno Cardoso ◽  
Alireza Sharifian
Keyword(s):  
Lattice Qcd ◽  
Flux Tube ◽  
Symmetric Case ◽  
Large Set ◽  
Flux Tubes ◽  
Pure Gauge ◽  
Generalized Eigenvalue ◽  
String Vibrations ◽  
Static Quark

Flux tube spectra are expected to have full towers of levels due to the quantization of the string vibrations. We study a spectrum of flux tubes with static quark and antiquark sources with pure gauge SU(3) lattice QCD in 3+1 dimensions up to a significant number of excitations. To go high in the spectrum, we specialize in the most symmetric case Σg+, use a large set of operators, solve the generalized eigenvalue and compare different lattice QCD gauge actions and anisotropies.

scholarly journals QCD flux tubes across the deconfinement phase transition

2018 ◽  
Vol 175 ◽  
pp. 12006 ◽  
Author(s):  
Paolo Cea ◽  
Leonardo Cosmai ◽  
Francesca Cuteri ◽  
Alessandro Papa
Keyword(s):  
Phase Transition ◽  
Flux Tube ◽  
Flux Tubes ◽  
Preliminary Results ◽  
Deconfinement Phase Transition ◽  
Static Quark

We study the behavior across the deconfinement phase transition of the chro-moelectric flux tube generated by a static quark and a static antiquark for several distances between them. We present preliminary results for distances up to 1.33 fm and temperatures up to 1.5Tc.

scholarly journals Colour fields of the quark-antiquark excited flux tube

2018 ◽  
Vol 175 ◽  
pp. 14009 ◽  
Author(s):  
Pedro Bicudo ◽  
Marco Cardoso ◽  
Nuno Cardoso
Keyword(s):  
Flux Tube ◽  
Large Set ◽  
Density Profiles ◽  
Field Density ◽  
Gluonic Excitations ◽  
Static Quark

We present colour field density profiles for some of the first SU(3) gluonic excitations of the flux tube in the presence of a static quark-antiquark pair. The results are obtained from a large set of gluonic operators.

scholarly journals Ion velocity distributions within the LLBL and their possible implication to multiple reconnections

2004 ◽  
Vol 22 (1) ◽  
pp. 213-236 ◽  
Author(s):  
O. L. Vaisberg ◽  
L. A. Avanov ◽  
T. E. Moore ◽  
V. N. Smirnov
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Tube ◽  
Magnetic Flux Tube ◽  
Flux Tubes ◽  
Different Types ◽  
Subsolar Point ◽  
Magnetic Flux Tubes ◽  
Ion Velocity ◽  
Field Lines

Abstract. We analyze two LLBL crossings made by the Interball-Tail satellite under a southward or variable magnetosheath magnetic field: one crossing on the flank of the magnetosphere, and another one closer to the subsolar point. Three different types of ion velocity distributions within the LLBL are observed: (a) D-shaped distributions, (b) ion velocity distributions consisting of two counter-streaming components of magnetosheath-type, and (c) distributions with three components, one of which has nearly zero parallel velocity and two counter-streaming components. Only the (a) type fits to the single magnetic flux tube formed by reconnection between the magnetospheric and magnetosheath magnetic fields. We argue that two counter-streaming magnetosheath-like ion components observed by Interball within the LLBL cannot be explained by the reflection of the ions from the magnetic mirror deeper within the magnetosphere. Types (b) and (c) ion velocity distributions would form within spiral magnetic flux tubes consisting of a mixture of alternating segments originating from the magnetosheath and from magnetospheric plasma. The shapes of ion velocity distributions and their evolution with decreasing number density in the LLBL indicate that a significant part of the LLBL is located on magnetic field lines of long spiral flux tube islands at the magnetopause, as has been proposed and found to occur in magnetopause simulations. We consider these observations as evidence for multiple reconnection Χ-lines between magnetosheath and magnetospheric flux tubes. Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; solar wind-magnetosphere interactions)

scholarly journals Linking Thin Flux Tube MHD Models to Apparent Stellar Surface Activity

2004 ◽  
Vol 219 ◽  
pp. 546-551
Author(s):  
T. Granzer ◽  
K. G. Strassmeier
Keyword(s):  
Magnetic Flux ◽  
Surface Activity ◽  
Flux Tube ◽  
Convection Zone ◽  
Active Regions ◽  
Similar Model ◽  
Flux Tubes ◽  
Stellar Convection ◽  
Magnetic Flux Tubes ◽  
Spot Formation

We model thin magnetic flux tubes as they rise from the bottom of a stellar convection zone to the photosphere. On emergence they form active regions, i.e. star spots. This model was very successfully applied to the solar case, where the simulations where in agreement with the butterfly diagram, Joy's law, and Hale's law. We propose the use of a similar model to describe stellar activity in the more extreme form found on active stars. A comparison between Doppler-images of well-observed pre-MS stars and a theoretically derived probability of star-spot formation as a function of latitude is presented.

scholarly journals Pure gauge flux tubes and their widths at finite temperature

2019 ◽  
Vol 940 ◽  
pp. 88-112
Author(s):  
P. Bicudo ◽  
N. Cardoso ◽  
M. Cardoso
Keyword(s):  
Finite Temperature ◽  
Flux Tubes ◽  
Pure Gauge

scholarly journals Dynamical Effects in Solar Photospheric Flux Tubes

1996 ◽  
Vol 154 ◽  
pp. 155-158
Author(s):  
S.S. Hasan
Keyword(s):  
Flux Tube ◽  
Ambient Medium ◽  
Resonant Interaction ◽  
Scale Height ◽  
Mhd Equations ◽  
Time Dependent ◽  
Radiative Transport ◽  
Local Pressure ◽  
Flux Tubes ◽  
Pressure Scale

AbstractThe interaction of an intense flux tube, extending vertically through the photosphere, with p-modes in the ambient medium is modelled by solving the time dependent MHD equations in the thin flux tube approximation. It is found that a resonant interaction can occur, which leads to the excitation of flux tube oscillations with large amplitudes. The resonance is not as sharp as in the case of an unstratified atmosphere, but is broadened by a factor proportional to H−2, where H is the local pressure scale height. In addition, the inclusion of radiative transport leads to a decrease in the amplitude of the oscillations, but does not qualitatively change the nature of the interaction.

scholarly journals Flux Tube Shredding and its Infrared Signature

1994 ◽  
Vol 154 ◽  
pp. 459-463
Author(s):  
M. Bünte ◽  
O. Steiner ◽  
S.K. Solanki ◽  
V.J. Pizzo
Keyword(s):  
Magnetic Flux ◽  
Flux Tube ◽  
Flux Tubes ◽  
Infrared Signature ◽  
Magnetic Tension ◽  
Magnetic Flux Tubes ◽  
Interchange Instability

The interchange instability of solar magnetic flux tubes and possible stabilization mechanisms are reviewed. Special attention is paid to the influence of magnetic tension forces and the internal atmosphere, both of which were neglected in earlier studies of this instability. It is found that whirl flows with velocities of only 2.2 km s–1 are strong enough to stabilize the flux tubes. However, their absence or the excitation of other instabilities might lead to a shredding of the tubes. The observability of such a scenario in the infrared is briefly discussed.

scholarly journals The increase of curvature radius of geomagnetic field lines preceding a classical dipolarization

2019 ◽  
Author(s):  
Osuke Saka
Keyword(s):  
Field Line ◽  
Electric Fields ◽  
Flux Tube ◽  
Slow Wave ◽  
Equatorial Plane ◽  
Curvature Radius ◽  
Flux Tubes ◽  
Ballooning Instability ◽  
Field Lines ◽  
Bursty Bulk Flows

Abstract. Downstream observations at geosynchronous altitudes of field line dipolarization exhibit fundamental component of substorms associated with high velocity magnetotail flow bursts referred to as Bursty Bulk Flows. In growth phase of substorms, we found that the magnetosphere at geosynchronous orbit are in unstable conditions for Ballooning instability due to the appreciable tailward stretching of the flux tubes, and for slow magnetoacoustic wave due to the continuing field-aligned inflows of plasma sheet plasmas towards the equatorial plane. We propose following scenario of field line dipolarization in downstream locations; (1) The slow wave was excited through Ballooning instability by the arrival of Dipolarization Front at the leading edge of Bursty Bulk Flows. (2) In the equatorial plane, slow wave stretched the flux tube in dawn-dusk directions, which resulted in the spreading plasmas in dawn-dusk directions and reducing the radial pressure gradient in the flux tube. (3) As a result, the flux tube becomes a new equilibrium geometry in which curvature radius of new field lines increased in meridian plane, suggesting an onset of field line dipolarization. (4) Increasing curvature radius induced inductive electric fields of the order of few mV/m pointing westward in the equatorial plane, as well as radial electric fields associated with stretching flux tubes in dawn-dusk directions. Westward electric fields transmitted to the ionosphere produce a dynamic ionosphere where the E layer contains both dynamo (E · J  0) processes in it for generating field-aligned current system of Bostrom type. The dipolarization processes associated with changing the curvature radius occurred in the transitional intervals lasting for about 10 minutes preceding classical dipolarization composed of reduction of cross-tail currents and pileup of the magnetic fields transported from the tail.

scholarly journals Flux tubes in Nf = 2 + 1 QCD with external magnetic fields

2018 ◽  
Vol 175 ◽  
pp. 12008 ◽  
Author(s):  
Claudio Bonati ◽  
Salvatore Calì ◽  
Massimo D’Elia ◽  
Michele Mesiti ◽  
Francesco Negro ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Tree Level ◽  
Magnetic Field Direction ◽  
Physical Point ◽  
Flux Tubes ◽  
Gauge Action ◽  
Uniform External Magnetic Field ◽  
Static Quark ◽  
The Magnetic Field

We study the behavior of the confining flux tube in Nf = 2 + 1 QCD at the physical point, discretized with the stout smearing improved staggered quark action and the tree level Symazik gauge action. We discuss how it depends on a uniform external magnetic field, showing how it displays anisotropies with respect to the magnetic field direction. Moreover, we compare the observed anisotropy pattern with that of the static quark-antiquark (QQ̅) potential we obtained in [1, 2].

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