HEP Lattice·hep-lat
5 papers—4 primary·1 cross-listed·reconstructed*
K. Jansen🇩🇪 · A. Nube🇩🇪 · A. Shindler🇩🇪 · C. Urbach🇬🇧 · U. Wenger🇨🇭
In this proceeding contribution we report on a first study in order to explore the so called epsilon regime with Wilson twisted mass (Wtm) fermions. To show the potential of this approach we give a preliminary determination of the chiral condensate.
Tatsuo Azeyanagi🇯🇵 · Masanori Hanada🇮🇱 · Tomoyoshi Hirata🇯🇵 · Tomomi Ishikawa🇺🇸
Twisted Eguchi-Kawai model is a useful tool for studying the large-N gauge theory. It can also provide a nonperturbative formulation of the gauge theory on noncommutative spaces. Recently it was found that the Z_N^4 symmetry in this model, which is crucial for the above applications, can break spontaneously in the intermediate coupling region. In this article, we study the phase structure of this model using the Monte-Carlo simulation. In particular, we elaborately investigate the symmetry breaking point from the weak coupling side. The simulation results show that we cannot take a continuum limit for this model.
T. T. Takahashi🇯🇵 · T. Kunihiro🇯🇵
We report the first lattice QCD result of the axial charge of N(1535), . The measurement is performed with two flavors of dynamical quarks employing the renormalization-group improved gauge action at =1.95 and the mean-field improved clover quark action with the hopping parameters, =0.1375, 0.1390 and 0.1400. In order to avoid the signal contaminations by N(1650) lying just 100 MeV above N(1535), we construct 22 correlation matrices and diagonalize them so that clear signal separation can be found. The wraparound contributions in the correlator, which can be another source of signal contamination, are eliminated by imposing the Dirichlet boundary condition in the temporal direction. We find that the axial charge of N(1535) takes small values as , independent of quark masses, in the pion-mass range of 0.7 to 1.1 GeV.
Dietrich Bodeker (1)🇩🇪 · Kari Rummukainen (2) ((1) Bielefeld University, (2) University of Oulu)🇫🇮
Under suitable non-equilibrium conditions QCD plasma can develop plasma instabilities, where some modes of the plasma grow exponentially. It has been argued that these instabilities can play a significant role in the thermalisation of the plasma in heavy-ion collision experiments. We study the instability in SU(2) plasmas using the hard thermal loop effective lattice theory, which is suitable for studying real-time evolution of long wavelength modes in the plasma. We observe that under suitable conditions the plasma can indeed develop an instability which can grow to a very large magnitude, necessary for the rapid thermalisation in heavy-ion collisions.
An overview of recent results with CLAS is presented with emphasis on nucleon resonance studies, nucleon spin structure, and generalized parton distributions.
* 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.