6,258 research outputs found
Direct solution of the hard pomeron problem for arbitrary conformal weight
A new method is applied to solve the Baxter equation for the one dimensional
system of noncompact spins. Dynamics of such an ensemble is equivalent to that
of a set of reggeized gluons exchanged in the high energy limit of QCD
amplitudes. The technique offers more insight into the old calculation of the
intercept of hard Pomeron, and provides new results in the odderon channel.Comment: Contribution to the ICHEP96 Conference, July 1996, Warsaw, Poland.
LaTeX, 4 pages, 3 epsf figures, includes modified stwol.sty file. Some
references were revise
New representation for the odderon wave function
New representation of the odderon wave function is derived, which is
convergent in the whole impact parameter plane and provides the analytic form
of the quantization condition for the integral of motion q_3. A new quantum
number, triality, is identified. This, together with the choice of the
conformal basis, allows for simple calculation of eigenvalues of a wide class
of operators.Comment: 15 pages, latex, one .eps figur
Towards the lattice study of M-theory
We propose the Wilson discretization of the supersymmetric Yang-Mills Quantum
Mechanics as a lattice version of the matrix model of M-theory. An SU(2) model
is studied numerically in the quenched approximation for D=4. A clear signal
for the existence of two different phases is found and the continuum
pseudocritical temperature is determined. We have also extracted the continuum
limit of the total size of the system in both phases and for different
temperatures.Comment: Lattice 2000 (Gravity and Matrix Models
Effective Low Energy Theories and QCD Dirac Spectra
We analyze the smallest Dirac eigenvalues by formulating an effective theory
for the QCD Dirac spectrum. We find that in a domain where the kinetic term of
the effective theory can be ignored, the Dirac eigenvalues are distributed
according to a Random Matrix Theory with the global symmetries of the QCD
partition function. The kinetic term provides information on the slope of the
average spectral density of the Dirac operator. In the second half of this
lecture we interpret quenched QCD Dirac spectra at nonzero chemical potential
(with eigenvalues scattered in the complex plane) in terms of an effective low
energy theory.Comment: Invited talk at the 10th International Conference on Recent Progress
in Many-Body Theories (MBX), Seattle, September 1999, 13 pages, Latex, with 1
figure, uses ws-p9-75x6-50.cl
Solution of the Odderon Problem
The intercept of the odderon trajectory is derived, by finding the spectrum
of the second integral of motion of the three reggeon system in high energy
QCD. When combined with earlier solution of the appropriate Baxter equation,
this leads to the determination of the low lying states of that system. In
particular, the energy of the lowest state gives the intercept of the odderon
alpha_O(0)=1-0.2472 alpha_s N_c/pi.Comment: 11 pages, 2 Postscript figure
Spectral Curves of Non-Hermitean Hamiltonians
Recent analytical and numerical work have shown that the spectrum of the
random non-hermitean Hamiltonian on a ring which models the physics of vortex
line pinning in superconductors is one dimensional. In the maximally
non-hermitean limit, we give a simple "one-line" proof of this feature. We then
study the spectral curves for various distributions of the random site
energies. We find that a critical transition occurs when the average of the
logarithm of the random site energy squared vanishes. For a large class of
probability distributions of the site energies, we find that as the randomness
increases the energy at which the localization-delocalization transition occurs
increases, reaches a maximum, and then decreases. The Cauchy distribution
studied previously in the literature does not have this generic behavior. We
determine the critical value of the randomness at which "wings" first appear in
the energy spectrum. For distributions, such as Cauchy, with infinitely long
tails, we show that this critical value is infinitesimally above zero. We
determine the density of eigenvalues on the wings for any probability
distribution. We show that the localization length on the wings diverges
linearly as the energy approaches the energy at which the
localization-delocalization transition occurs. These results are all obtained
in the maximally non-hermitean limit but for a generic class of probability
distributions of the random site energies.Comment: 36 pages, 5 figures (.ps), LaTe
A study of the influence of Hg(6(3)P2) population in a low-pressure discharge on mercury ion emission at 194.2 nm
A low-pressure mercury-argon discharge, similar to the type existing in the mercury lamp for the trapped-ion standard, is probed with a new technique of laser spectroscopy to determine the influence of the Hg(6 3P(sub 2)) population on discharge emission. The discharge is excited with inductively coupled rf power. Variations in the intensity of emission lines in the discharge were examined as lambda = 546.1 nm light from a continuous wave (CW) laser excited the Hg(6 3P(sub 2)) to (7 3S (sub 1)) transition. The spectrum of the discharge viewed in the region of laser irradiation showed increased emission in lambda = 546.1, 435.8, 404.7, 253.7, and 194.2 nm lines. Other lines in Hg I exhibited a decrease in emission. When the discharge was viewed outside the region of laser irradiation, all lines exhibited an increased emission. Based on these results, it is concluded that the dominant mechanism for the excitation of higher lying levels of mercury is the the electron-impact excitation via the 3P(sub 2) level. The depopulation of this metastable is also responsible for the observed increase in the electron temperature when the laser irradiates the discharge. It is also concluded that the 3P(sub 2) metastable level of mercury does not play a significant role in the excitation of the 3P(sub 1/2) level of mercury ion
Simple analytic potentials for linear ion traps
A simple analytical model was developed for the electric and ponderomotive (trapping) potentials in linear ion traps. This model was used to calculate the required voltage drive to a mercury trap, and the result compares well with experiments. The model gives a detailed picture of the geometric shape of the trapping potenital and allows an accurate calculation of the well depth. The simplicity of the model allowed an investigation of related, more exotic trap designs which may have advantages in light-collection efficiency
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