HEP Lattice·hep-lat
5 papers—3 primary·2 cross-listed·reconstructed*
M. Guagnelli🇮🇹 · J. Heitger🇩🇪 · C. Pena🇩🇪 · A. Vladikas🇮🇹
Some new results on nonperturbative renormalisation of quark bilinears in quenched QCD with Schroedinger Functional techniques are presented. Special emphasis is put on a study of the universality of the continuum limit for step scaling functions computed with different levels of O(a) improvement.
A. Ali Khan🇩🇪 · T. Bakeyev🇷🇺 · M. Göckeler🇩🇪 · T.R. Hemmert🇩🇪 · R. Horsley🇬🇧 · A.C. Irving🇬🇧 · D. Pleiter🇩🇪 · P.E.L. Rakow🇬🇧 · G. Schierholz🇩🇪 · H. Stüben (the QCDSF Collaboration and the UKQCD Collaboration)🇩🇪
We calculate finite size effects on nucleon masses in chiral perturbation theory. We confront the theoretical predictions with N_f=2 lattice results and discuss chiral extrapolation formulae.
P. Dimopoulos🇮🇹 · J. Heitger🇩🇪 · C. Pena🇩🇪 · S. Sint🇪🇸 · A. Vladikas🇮🇹
We present some preliminary results for at , using the twisted mass QCD formalism for the computation of bare matrix elements of the operator. The main advantage of the method is that mixing with other operators under renormalisation is avoided. Moreover the operator renormalisation is performed in the Schrödinger functional (SF) framework, using earlier results of our collaboration for the corresponding step scaling function.
Florian Bauer🇩🇪 · Manfred Lindner🇩🇪 · Gerhart Seidl🇺🇸
We demonstrate that by employing the correspondence between gauge theories in geometric and in deconstructed extra dimensions, it is possible to transfer the methods for calculating finite Casimir energy densities in higher dimensions to the four-dimensional deconstruction setup. By this means, one obtains an unambiguous and well-defined prescription to determine finite vacuum energy contributions of four-dimensional quantum fields which have a higher-dimensional correspondence. Thereby, large kink masses lead to an exponentially suppressed Casimir effect. For a specific model we hence arrive at a small and positive contribution to the cosmological constant in agreement with observations.
Gaku Arakawa🇯🇵 · Ikuo Ichinose🇯🇵
In the present paper we shall study (2+1) dimensional Z_N gauge theories on a lattice. It is shown that the gauge theories have two phases, one is a Higgs phase and the other is a confinement phase. We investigate low-energy excitation modes in the Higgs phase and clarify relationship between the Z_N gauge theories and Kitaev's model for quantum memory and quantum computations. Then we study effects of random gauge couplings(RGC) which are identified with noise and errors in quantum computations by Kitaev's model. By using a duality transformation, it is shown that time-independent RGC give no significant effects on the phase structure and the stability of quantum memory and computations. Then by using the replica methods, we study Z_N gauge theories with time-dependent RGC and show that nontrivial phase transitions occur by the RGC.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.