Pseudoscalar flavor-singlets and staggered fermions

نویسندگان

  • Eric B. Gregory
  • Alan C. Irving
  • Christopher M. Richards
  • Craig McNeile
چکیده

The Asqtad improved staggered fermion formalism has been a valuable tool in successfully calculating the non-singlet parts of the hadronic spectrum. We are engaged in a project to calculate the spectrum of the pseudoscalar singlet mesons with 2 + 1-flavor Asqtad staggered gauge configurations. Propagators of flavor-singlet states incorporate contributions from both disconnected and connected diagrams, and hence are sensitive to any differences in the actions governing the sea and valence fermions on the lattice. As such, they also present the possibility of a probe of the validity of the “fourth-root trick” in the staggered fermion formulation. We present an update on our progress toward measuring the η ′ mass on 2+1-flavor Asqtad staggered gauge configurations, including a review of methods and preliminary results. We also show a strong correlation between Tr(γ5 ⊗ 1) and the topological charge in these configurations, as predicted by the index theorem.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

ar X iv : 0 71 0 . 17 25 v 1 [ he p - la t ] 9 O ct 2 00 7 Pseudoscalar Flavor - Singlet Physics with Staggered

Accurately calculating the mass of flavor-singlet meson states from numerical lattice simulations is an important milestone for lattice QCD. Careful measurement of the full pseudoscalar flavorsinglet propagator is also a crucial step in understanding the dynamics of the fermion sea on the lattice, in particular for potentially non-trivial formulations such as with 2+1-flavor staggered fermions....

متن کامل

ar X iv : h ep - l at / 0 51 10 38 v 1 1 7 N ov 2 00 5 Towards measuring the η ′ mass with N f = 2 + 1 staggered fermions

Because the propagators of flavor-singlet states incorporate disconnected diagrams, they are uniquely sensitive to any differences in the actions governing sea and valence fermions on the lattice. As such, they present an important test of the validity of the “fourth-root trick” in the staggered fermion formulation. The pseudoscalar’s relationship to topological charge also makes it of theoreti...

متن کامل

Pseudoscalar Singlet Physics with Staggered Fermions

We report on progress in measuring disconnected correlators associated with pseudoscalar flavorsinglet mesons. This will eventually allow us to compute the masses of the eta and eta’ mesons. Flavor-singlet physics also presents an interesting test of the staggered fermion formulation, as disconnected correlators are sensitive to whether the same action governs both sea quarks and valence quarks...

متن کامل

A High Statistics Study of Flavour - Singlet Mesons with Staggered Fermions

We present some early results from a high statistics study of the scalar and pseudoscalar singlet sectors of lattice QCD using 2 + 1 flavours of Asqtad improved staggered fermions. The use of the Asqtad action has allowed us to generate an unprecedented number of configurations at 2 lattice spacings which on completion we hope will give us a significantly improved view of both the scalar and ps...

متن کامل

Improved Bilinears in Unquenched Lattice Qcd *

It is important to pursue simulations with Wilson-like fermions, despite their greater computational cost than staggered fermions, because one avoids the theoretical uncertainty associated with taking roots of the fermion determinant. One drawback with Wilson fermions is that they lead to discretization errors of O(a), slowing the approach to the continuum. This can be ameliorated using anO(a) ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2006