Exoti hybrid mesons from improved Kogut-Susskind fermions

C. Bernard Department of Physi s, Washington University, St. Louis, MO 63130, USA T. Bur h, E.B. Gregory, and D. Toussaint Department of Physi s, University of Arizona,Tu son, AZ 85721, USA C. DeTar and J. Osborn Physi s Department, University of Utah, Salt Lake City, UT 84112, USA Steven Gottlieb Department of Physi s, Indiana University,Bloomington, IN 47405, USA U.M. Heller Ameri an Physi al So iety, One Resear h Road, Box 9000,Ridge, NY 11961-9000 R. Sugar Department of Physi s, University of California, Santa Barbara, CA 93106, USA (Dated: January 10, 2003) Abstra t We summarize our determination of the mass of the exoti 1 + hybrid meson using an improved Kogut-Susskind a tion. We show results from both quen hed and dynami al quark simulations and ompare with results from Wilson quarks at heavier quark masses. The results on latti es with three avors of dynami al quarks show e e ts of sea quarks on the hybrid propagators whi h probably result from oupling to two meson states. Extrapolation of the quen hed results to the physi al quark mass allows omparison with experimental andidates for the 1 + hybrid meson. The latti e result remains heavier than the experimental result, although it is possibly onsistent with the 1(1600). PACS numbers: