Krzysztof Cichy

  • Citations Per Year
Learn More
We present results of applying the Hamiltonian approach to the massless Schwinger model. A finite basis is constructed using the strong coupling expansion to a very high order. Using exact diagonalization, the continuum limit can be reliably approached. This allows to reproduce the analytical results for the ground state energy, as well as the vector and(More)
We investigate BB̄ systems by computing potentials of two static quarks in the presence of two quarks of finite mass using lattice QCD. By solving the Schrödinger equation we check whether these potentials are sufficiently attractive to host bound states. Particular focus is put on the experimentally most promising bottomonium-like tetraquark candidate Z± b(More)
The COntractor REnormalization group method was devised in 1994 by Morningstar and Weinstein. It was primarily aimed at extracting the physics of lattice quantum field theories (like lattice Quantum Chromodynamics). However, it is a general method of analyzing Hamiltonian lattice systems, e.g. Ising, Heisenberg or Hubbard models. The aim of this work is to(More)
We present results from an ongoing computation of masses of D mesons, Ds mesons and charmonium, including both ground states and several parity and angular momentum excitations. We employ 2+1+1 flavours of dynamical maximally twisted mass fermions at three lattice spacings and three u/d quark masses at each lattice spacing. We consider different(More)
We numerically study the zero temperature phase structure of the multiflavor Schwinger model at nonzero chemical potential. Using matrix product states, we reproduce analytical results for the phase structure for two flavors in the massless case and extend the computation to the massive case, where no analytical predictions are available. Our calculations(More)
The topological susceptibility is an important quantity in QCD, which can be computed using lattice methods. However, at a fine lattice spacing, or when using high quality chirally symmetric quarks, algorithms which proceed in small update steps — in particular the HMC algorithm — tend to get stuck in a single topological sector. In such cases, the(More)
Short-distance singularities in lattice correlators can modify their Symanzik expansion by leading to additional O(a) lattice artifacts. At the example of the chiral condensate and the topological susceptibility, we show how to account for these lattice artifacts for Wilson twisted mass fermions and show that the property of automatic O(a) improvement is(More)
Krzysztof Cichy∗abc†, Arthur Dromardb, Elena Garcia-Ramosad, Konstantin Ottnade f , Carsten Urbach f , Marc Wagnerb, Urs Wengerg, Falk Zimmermann f aJohn von Neumann Institute for Computing (NIC), DESY, Platanenallee 6, 15738 Zeuthen, Germany bGoethe-Universität Frankfurt am Main, Institut für Theoretische Physik, Max-von-Laue-Straße 1, D-60438 Frankfurt am(More)
  • 1