Lattice Generation and Sharing Guide Lines of USQCD (aka SciDAC)

1. Lattice Generation and Sharing Guide Lines of USQCD (aka SciDAC) Richard C. Brower ILDG5 Dec 3, 2004 The U.S. Lattice QCD Executive Committee has been discussing the sharing of data. Since the RBRC, UKQCD and SciDAC collaborations will have the most powerful computers dedicated to lattice gauge theory in the immediate future, it would be worthwhile to see if these three groups can agree on a common policy. (Excerpts of recent USQCD discussions.)

2. Evolving Discussion in USQCD • We believe that coordinating the generation of lattices with other groups and sharing the resulting lattices with our partners offers the greatest opportunity to amplify our computing resources. Initially, SciDAC will focus on some form of domain wall or overlap quarks and on improved staggered quarks. We understand that members of UKQCD are also interested in these quark actions, and that RBRC is interested in domain wall quarks. So, there appear to be significant opportunities for joint efforts among the three groups. • Although we believe that all lattices produced in large scale production simulations should eventually be made publicly available, given the large investments our funding agencies are making in their generation, it seems reasonable that the groups producing them should have some period of exclusive use. We hope that a consensus on the length of this period can be reached.

3. Generalized guide lines for ILDG sharing • All lattices generated through the coordinated effort of two or more groups would be shared promptly. The ILDG will be informed of lattice parameters and schedule for large scale lattice simulations. • Those generating the lattices would have the option of specifying a limited number of projects for which they would have exclusive use of the lattices for a limited period of time. • Those members of the participating collaborations who were not involved in generating lattices, but wished to use them, should make public their plans.