2,447 research outputs found
Lattice QCD investigation of a doubly-bottom tetraquark with quantum numbers
We use lattice QCD to investigate the spectrum of the
four-quark system with quantum numbers . We use five different
gauge-link ensembles with flavors of domain-wall fermions, including one
at the physical pion mass, and treat the heavy quark within the
framework of lattice nonrelativistic QCD. Our work improves upon previous
similar computations by considering in addition to local four-quark
interpolators also nonlocal two-meson interpolators and by performing a
L\"uscher analysis to extrapolate our results to infinite volume. We obtain a
binding energy of , corresponding to the
mass , which confirms the existence of a
tetraquark that is stable with respect to the strong and
electromagnetic interactions.Comment: 27 pages, 13 figure
Baryon Spectroscopy in Lattice QCD
We review recent developments in the study of excited baryon spectroscopy in
lattice QCD. After introducing the basic methods used to extract masses from
correlation functions, we discuss various interpolating fields and lattice
actions commonly used in the literature. We present a survey of results of
recent calculations of excited baryons in quenched QCD, and outline possible
future directions in the study of baryon spectra.Comment: Contribution to Lecture Notes in Physics on Lattice Hadron Physics,
43 pages, 11 figures, 3 table
Perspectives of Nuclear Physics in Europe: NuPECC Long Range Plan 2010
The goal of this European Science Foundation Forward Look into the future of Nuclear Physics is to bring together
the entire Nuclear Physics community in Europe to formulate a coherent plan of the best way to develop the field in
the coming decade and beyond.<p></p>
The primary aim of Nuclear Physics is to understand the origin, evolution, structure and phases of strongly interacting matter, which constitutes nearly 100% of the visible matter in the universe. This is an immensely important and challenging task that requires the concerted effort of scientists working in both theory and experiment, funding agencies, politicians and the public.<p></p>
Nuclear Physics projects are often “big science”, which implies large investments and long lead times. They need careful forward planning and strong support from policy makers. This Forward Look provides an excellent tool to achieve this. It represents the outcome of detailed scrutiny by Europe’s leading experts and will help focus the views of the scientific community on the most promising directions in the field and create the basis for funding agencies to provide adequate support.<p></p>
The current NuPECC Long Range Plan 2010 “Perspectives of Nuclear Physics in Europe” resulted from consultation
with close to 6 000 scientists and engineers over a period of approximately one year. Its detailed recommendations
are presented on the following pages. For the interested public, a short summary brochure has been produced to
accompany the Forward Look.<p></p>
Perturbative Improvement for Lattice QCD: An Update
Recent developments in the Symanzik improvement program for lattice QCD are
reviewed.Comment: Invited talk at the workshop on "Lattice QCD on Parallel Computers"
(Tsukuba, March 1997). One file producing 12 pages; LaTe
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