Mon·Oct 29, 2007Monday·October 29, 2007

1. 01*

   Chiral behavior of pseudo-Goldstone boson masses and decay constants in 2+1 flavor QCD

   S. Durr (1)🇨🇭 · Z. Fodor (1,2,3)🇩🇪 · C. Hoelbling (2,5)🇩🇪 · S.D. Katz (2,3)🇭🇺 · S. Krieg (2,4)🇩🇪 · Th. Kurth (2)🇩🇪 · L. Lellouch (5)🇫🇷 · Th. Lippert (1,2,4)🇩🇪 · K.K. Szabo (2)🇩🇪 · G. Vulvert (5) ((1) NIC Zeuthen/Juelich, (2) Wuppertal U., (3) Eotvos U., (4) JSC, FZ Juelich, (5) Marseille, CPT)🇫🇷

   We present preliminary results for the chiral behavior of charged pseudo-Goldstone-boson masses and decay constants. These are obtained in simulations with N_f=2+1 flavors of tree-level, O(a)-improved Wilson sea quarks. In these simulations, mesons are composed of either valence quarks discretized in the same way as the sea quarks (unitary simulations) or of overlap valence quarks (mixed-action simulations). We find that the chiral behavior of the pseudoscalar meson masses in the mixed-action calculations cannot be explained with continuum, partially-quenched chiral perturbation theory. We show that the inclusion of O(a^2) unitarity violations in the chiral expansion resolves this discrepancy and that the size of the unitarity violations required are consistent with those which we observe in the zero-momentum, scalar-isotriplet-meson propagator.

   hep-lathep-phPoS(2007)·15 citations
2. 02*

   Quark number susceptibility of high temperature and finite density QCD

   Ari Hietanen🇫🇮 · Kari Rummukainen🇫🇮

   We utilize lattice simulations of the dimensionally reduced effective field theory (EQCD) to determine the quark number susceptibility of QCD at high temperature ($T>2T_c$). We also use analytic continuation to obtain results at finite density. The results extrapolate well from known perturbative expansion (accurate in extremely high temperatures) to 4d lower temperature lattice data

   hep-latPoS(2007)·5 citations
3. 03*

   Kl3 semileptonic form factor from 2+1 flavour lattice QCD

   P.A. Boyle🇬🇧 · A. Jüttner🇩🇪 · R.D. Kenway🇬🇧 · C.T. Sachrajda🇬🇧 · S. Sasaki🇯🇵 · A. Soni🇺🇸 · R.J. Tweedie🇬🇧 · J.M. Zanotti🇬🇧

   We present the first results for the Kl3 form factor from simulations with 2+1 flavours of dynamical domain wall quarks. Combining our result, namely f_+(0)=0.964(5), with the latest experimental results for Kl3 decays leads to |V_{us}|=0.2249(14), reducing the uncertaintity in this important parameter. For the O(p^6) term in the chiral expansion we obtain \Delta f=-0.013(5).

   hep-lathep-phPRL(2008)·145 citations
4. 04*

   Heavy quark free energies for three quark systems at finite temperature

   K. Huebner🇺🇸 · F. Karsch🇺🇸 · O. Kaczmarek🇩🇪 · O. Vogt🇩🇪

   We study the free energy of static three quark systems in singlet, octet, decuplet and average color channels in the quenched approximation and in 2-flavor QCD at finite temperature. We show that in the high temperature phase singlet and decuplet free energies of three quark systems are well described by the sum of the free energies of three diquark systems plus self energy contributions of the three quarks. In the confining low temperature phase we find evidence for a Y-shaped flux tube in SU(3) pure gauge theory, which is less evident in 2-flavor QCD due to the onset of string breaking. We also compare the short distance behavior of octet and decuplet free energies to the free energies of single static quarks in the corresponding color representations.

   hep-lathep-phPRD(2008)·32 citations

* 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.