Instructive discussion of an effective block algorithm for baryon-baryon correlators

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• 作者：Hidekatsu Nemura ^{nemura.hidekatsu.gb@u.tsukuba.ac.jp" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Nuclear force ; Lattice QCD ; Hyperon&ndash ; nucleon interaction ; Hypernuclei
• 刊名：Computer Physics Communications
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：207
• 期：Complete
• 页码：91-104
• 全文大小：1029 K

文摘

We describe an approach for the efficient calculation of a large number of four-point correlation functions for various baryon–baryon (4742707d402bca4a71b365e40b" title="Click to view the MathML source">BB$BB$) channels, which are the primary quantities for studying the nuclear and hyperonic nuclear forces from lattice quantum chromodynamics. Using the four-point correlation function of a proton-Λ$\Lambda$ system as a specific example, we discuss how an effective block algorithm significantly reduces the number of iterations. The effective block algorithm is applied to calculate 52 channels of the four-point correlation functions from nucleon–nucleon to Ξ$\Xi$–Ξ$\Xi$, in order to study the complete set of isospin symmetric 4742707d402bca4a71b365e40b" title="Click to view the MathML source">BB$BB$ interactions. The elapsed times measured for hybrid parallel computation on BlueGene/Q demonstrate that the performance of the present algorithm is reasonable for various combinations of the number of OpenMP threads and the number of MPI nodes. The numerical results are compared with the results obtained using the unified contraction algorithm for all computed sites of the 52 four-point correlators.