kavic_Poster0216
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Transcript kavic_Poster0216
Vishnu Jejjala,a Michael Kavic,b
Djordje Minic,b Chia Tze,b
a
IHES, Le Bois-Marie, 35, route des
Chartres, F-91440 Bures sur Yvette, France
b Department of Physics, Virginia Tech
Introduction
With the new Large Hadron Collider (LHC) becoming operational in the near
future, our understanding of quantum chromodynamics (QCD) is essential in analyzing
the data to be collected. One area in which we lack understanding is in the nonperturbative effects of the theory. Understanding the non-perturbative dynamics of YangMills theory will bring us one step closer to this goal. Currently, lattice gauge theory has
made great progress in understanding QCD, however, analytic understanding has not
come as far.
In our present work, we consider Yang-Mills theory in (2+1) and (3+1)
dimensions with a large number of colors. The primary focus of our research is to
construct the spectrum of gauge-invariant glueball states. In the 2+1 case, we use a
Hamiltonian approach proposed by Karabali, Kim, and Nair (1997) in which the theory is
rewritten in terms of gauge-invariant “corner” variables. Using this approach, analytic
computations can be done. In the 3+1 case, the Karabali, Kim, and Nair formalism is
extended from 2+1 to 3+1 using corner variables (Bars 1978). This extension allows us
to compute our results in 3+1 using the same physical insight and analytic tools as in the
2+1 case.
Vacuum Wave Functional
In 2+1 dimensions, we take as the vacuum wavefunctional ansatz
Comparison With Lattice
(2+1) 0++ states
The Scrödinger equation becomes
(2+1) 0– states
where E0 is a divergent vacuum energy
The kernel equation is
(2+1) 2++ and 2-+ states
which has a general solution in terms of Bessel functions
Only one solution is normalizable and has the correct asymptotics in the UV
and IR limits and it is given by
Summary of Results
(3+1) J++ states
Determined a new non-trivial form of the vacuum wavefunctional by solving
the Schrodinger equation for (2+1) and (3+1) Yang-Mills theory.
Computed glueball mass spectrum in (2+1) and (3+1) Yang-Mills theory. The
0++ glueball mass in (2+1) is statistically indistinguishable from the lattice
results!
UV:
IR:
In 3+1 dimensions, we take as the vacuum wave functional ansatz
Computed string tension to within 1% of lattice result.
Note that
in the 2+1 case
(3+1) J-+ states
The Schrödinger equation with this wave functional yields the kernel equation
Background
We begin with (2+1) Yang-Mills theory. The Hamiltonian for the system is
Again, only one normalizable solution with the correct asymptotics is found
QCD String
where E is conjugate to A in the temporal gauge A0 = 0. We choose the
dynamics fields to be
We quantize the system using
Observable quantities and physical states must be gauge-invariant as a
consequence of Gauss’ law
By calculating the expectation value of a large spatial Wilson loop, the string
tension is determined to be
The Bessel function is essentially sinusoidal, so its
zeros are evenly spaced (better for large n)
Thus, the predicted spectrum has approximate
degeneracies
This agrees within 1% of the lattice result
The spectrum is organized into bands concentrated
around a given level
Mass Spectrum
•Background Independent Matrix Theory
• We parameterize the gauge fields by
• M transforms linearly under gauge transformations
Glueball states may found by computing the equal-time correlators of gaugeinvariant probe operators with the correct JPC quantum numbers
Preliminary counting suggests that there is an
approximate (in the sense that the degeneracies are
not exact) Hagedorn spectrum of states
We believe that this is a basic manifestation of the
QCD string
For example, 0++ is probed using Tr (B2):
We can expand the kernel using the formula
Future Prospects
• Gauge-invariant variables are constructed using
• The volume measure of the configuration space is given by a hermitian
Wess-Zumino-Witten action
• The volume of the configuration space is finite.
• Let us introduce the current
• In terms of the current, the Yang-Mills Hamiltonian is
Extension of method to include fundamental
fermions (QCD) and other types of matter
to get
Application to Yang-Mills theories at finite
temperature
Computation of the spectrum of baryons
Mn are mass constituents given by
2+1:
Computation of scattering amplitudes
3+1:
where 2,n are the ordered zeros of J2 and 3,n are the ordered zeros of J2.
At large separation distances, we find contributions of single particle poles
•
Extension to supersymmetric and superconformal
gauge theories
Condensed matter and Statistical Mechanics
application: 3D Ising model, High-Tc
superconductivity, etc.
with
Glueball masses are a sum of their constituents.
• m is the ‘t Hooft coupling
References
R. G. Leigh, D. Minic and A. Yelnikov, Phys. Rev. Lett. 96:222001 (2006); hep-th/0512111.
R. G. Leigh, D. Minic and A. Yelnikov, hep-th/0604060.
L. Freidel, R. G. Leigh and D. Minic, Phys. Lett. B641:105-111 (2006); hep-th/0604184.
L. Freidel, hep-th/0604185.
L. Freidel, R. G. Leigh, D. Minic and A. Yelnikov, hep-th/0801.1113.