gluon polarization tensor in external field in su 3 theory n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Gluon Polarization Tensor in external field in SU(3) theory PowerPoint Presentation
Download Presentation
Gluon Polarization Tensor in external field in SU(3) theory

Loading in 2 Seconds...

play fullscreen
1 / 19

Gluon Polarization Tensor in external field in SU(3) theory - PowerPoint PPT Presentation


  • 73 Views
  • Uploaded on

M. Khandoga , V. Skalozub. Gluon Polarization Tensor in external field in SU(3) theory. New Physics and Quantim Chromodynamics at External Conditions 2011 May 5 Dnipropetrovsk. Introduction.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Gluon Polarization Tensor in external field in SU(3) theory' - cholena-harris


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
gluon polarization tensor in external field in su 3 theory

M. Khandoga, V. Skalozub

Gluon Polarization Tensor in external field in SU(3) theory

New Physics and Quantim Chromodynamics at External Conditions 2011

May 5

Dnipropetrovsk

introduction
Introduction
  • Magnetic field of order is spontaneously generated in QCD vacuum at high temperatureSuperdaisy resummations:A. O. Starinets, A. V. Vshivtsev, V. Ch. Zukovskii. Phys. Lett. B 322, 403 (1994)Lattice simulations:N.O. Agasian (2003), V. Demchik (2008).
  • Cosmological proof: Fermi-LAT Collaborationfound out, that relict intergalactic magnetic fields of order ~ 10-15 Gare observed (Science, Vol. 328. no. 5979, pp. 725 – 729, April 2010).
  • Peripheral collisions of heavy ions: magnetic field is generated by parts of nuclei, travelling by sides
su 2 gluodynamics in external field
SU(2)-gluodynamics in external field

- QCD Lagrangian

- Ghostfields

background gauge
Background gauge

Field potential А(х) is divided into external field B(x)andquantum fluctuations Q(x):

External field is chosen in the following form:

Lagrangian in background gauge:

Ghost Lagrangian

charged basis
Charged basis

Since external field is directed along 3rd axis in the color space, it is convenient to introduce the following basis, which is called charged:

su 3 gluodynamics in external field
SU(3)-gluodynamics in external field

Spatial structure remains unchanged

Now we have 8 degrees of freedom instead of 3 which results in 8 gauge particles.

One more external field is added, it has same spatial orientation and directed along 8th axis in color space.

su 3 gluodynamics lagrangian in background gauge
SU(3)-gluodynamics Lagrangian in background gauge

- SU(3) group structure constants.

Let’s switch to charged basis:

neutral gluons sector
Neutral gluons sector

Neutral gluons do not interact with each other. We can write interaction Lagrangians of both neutral gluons as a combination of SU(2)-like Lagrangians:

Every interaction Lagrangian has a structure, identical to SU(2) case.

Thus the polarization operator of neutral gluons in SU(3) theory can be brought to SU(2) case, already researched by M.Bordag, V. Skalozub, Phys. Rev. D 75, 125003 (2007)

slide12
In the recent paper (V.Skalozub, A. Strelchenko (2004)) it was found out, that two fields are generated. After reaching the deconfinement phase two fields are generated:

Spontaneous generation of magnetic fields at high temperature

But after reaching some temperature only one field remains:

Hence the behavior of field-dependant quantities differs significantly at high temperature. Let’s illustrate it on Debye mass.

debye mass
Debye mass

If electrical potential is surrounded by plasma, it has a limited reach:

Sometimes it is convenient to use an inverted quantity:

In QFT Debye screening is caused by vacuum polarization. Debye mass can be obtained from polarization operator:

In finite-temperature QCD there is a well-known result:

O. Kalashnikov (1984)

debye mass of neutral gluons
Debye mass of neutral gluons

Debye mass slightly grows at high temperature:

charged gluons sector
Charged gluons sector

In SU(3) theory charged gluons do interact with each other:

SU(2) case was researched in paper by M. Bordag and V. Skalozub Phys. Rev. D 77, 105013 (2008)

For polarization operators of charged gluons we get

charged gluons debye mass
Charged gluons Debye mass

Expressions for Debye mass:

Dependence on temperature:

conclusions
Conclusions
  • Gluon polarization operator in external field is obtained in SU(3) case. Significant differences with SU(2) gluodynamics are observed.
  • The spontaneously generated external field appears to reduce Debye mass.
  • Obtained result may be used for further research, finding gluon spectra and magnetic masses.