Two-loop diagrams in nonrelativistic QCD with elliptics

Exponential Elliptics Give Dimension Two

Using the theory of infinite iterated function systems, we show that the Julia set of any function of the type G = λ exp ◦F , λ ∈ C \ {0} and with F : C → Ĉ a non–constant elliptic function, has Hausdorff dimension two. However there exist elliptic functions F such that the Julia sets of the maps G = exp ◦F are nowhere dense in C.

Two - loop splitting functions in QCD ∗

We present the universal two-loop splitting functions that describe the limits of two-loop n-point amplitudes of massless particles when two of the momenta are collinear. To derive the splitting amplitudes, we take the collinear limits of explicit two-loop four-point helicity amplitudes computed in the ’t Hooft-Veltman scheme. The g → gg splitting amplitude has recently been computed using the ...

Loop scattering in two-dimensional QCD.

Using the integrability conditions that we recently obtained in QCD 2 with massless fermions, we arrive at a sufficient number of conservation laws to be able to fix the scattering amplitudes involving a local version of the Wilson loop operator.

The Improvement Program in Nonrelativistic Lattice QCD

Bottomonium above deconfinement in lattice nonrelativistic QCD.

We study the temperature dependence of bottomonium for temperatures in the range 0.4T(c) < T < 2.1T(c), using nonrelativistic dynamics for the bottom quark and full relativistic lattice QCD simulations for Nf = 2 light flavors on a highly anisotropic lattice. We find that the Υ is insensitive to the temperature in this range, while the χb propagators show a crossover from the exponential decay ...