{"id":3106,"date":"2009-10-08T18:08:25","date_gmt":"2009-10-08T22:08:25","guid":{"rendered":"https:\/\/www.bu.edu\/tech\/research\/scv_import\/visualization\/gallery\/instanton\/"},"modified":"2023-05-16T16:22:00","modified_gmt":"2023-05-16T20:22:00","slug":"instanton","status":"publish","type":"page","link":"https:\/\/www.bu.edu\/tech\/support\/research\/whats-happening\/highlights\/instanton\/","title":{"rendered":"Instantons and Monopoles are Locally Correlated with the Chiral Condensate"},"content":{"rendered":"<div style=\"margin-left: auto; margin-right: auto; text-align: center;\"><img src=\"https:\/\/www.bu.edu\/tech\/files\/2010\/03\/instanton_med.gif\" alt=\"instanton\" \/><\/div>\n<p>Stefan Thurner<br \/>\nDepartment of Electrical and Computer Engineering, Boston University<\/p>\n<p>M.C. Feurstein<br \/>\nDepartment of Electrical and Computer Engineering, Boston University<br \/>\nInstitut fur Kernphysik, Vienna , Austria<\/p>\n<p>H. Markum<br \/>\nInstitut fur Kernphysik, Vienna , Austria<\/p>\n<p>There is a spring-like force in the vacuum existing between quarks that binds them together into observable bound states. Our research shows that the cause of this force is structure in the vacuum. Excitations of the vacuum can cause it to manifest various physical features, such as magnetic charge (e.g., monopoles). Other features exist just for an instant in 4D Euclidian space-time (e.g., instantons). The vacuum is also characterized by quark\/antiquark creation\/annihilation, which can not be observed directly.<\/p>\n<p>We perform a mutual analysis of the topological and chiral vacuum structure of four-dimensional quantum chromodynamics on the lattice at finite temperature. Concerning the topological sector, correlation functions between the distributions of color magnetic monopoles in maximum abelian gauge and the densities of the topological charge are computed. An enhanced probability for monopoles inside the core of an instanton is found on gauge field average and in specific configurations. In the chiral sector, clear evidence is found that monopole loops and instantons are locally correlated with the quark condensate.<\/p>\n<h4>Video Sequences<\/h4>\n<p><a href=\"\/h4&gt; &lt;a name=&quot;INSTANTON1&quot; href=&quot;http:\/\/scv.bu.edu\/SCV\/vizgal\/instanton\/instanton_movie.mpg&quot; id=&quot;INSTANTON1\"><img loading=\"lazy\" src=\"https:\/\/www.bu.edu\/tech\/files\/2010\/03\/instanton.gif\" alt=\"Link opens video\" align=\"left\" hspace=\"5\" width=\"133\" height=\"100\" class=\"alignnone\" \/><\/a><\/p>\n<p><a href=\"\/h4&gt; &lt;a name=&quot;INSTANTON1&quot; href=&quot;http:\/\/scv.bu.edu\/SCV\/vizgal\/instanton\/instanton_movie.mpg&quot; id=&quot;INSTANTON1\">Video Sequence<\/a><\/p>\n<p>In the video sequence, a time slice of a typical configuration with dynamical quarks on the 8^3&#215;4 lattice in the confinement phase is shown. The positive instanton density is denoted by colors in the blue range and the negative density by colors in the red range. Quark-anitquark density is shown in green. This work shows that there is enhanced virtual quark activity at the locations of instantons.<\/p>\n<h4>Still Images<\/h4>\n<div class=\"alignleft\" style=\"clear: left; padding-right: 10px;\"><img src=\"https:\/\/www.bu.edu\/tech\/files\/2010\/03\/cooling1.gif\" alt=\"instanton\" align=\"left\" hspace=\"5\" \/><\/div>\n<p>Cooling Step 0 &#8211; No discernible structure.<\/p>\n<div style=\"clear: left;\"><\/div>\n<div class=\"alignleft\" style=\"clear: left; padding-right: 10px;\"><img src=\"https:\/\/www.bu.edu\/tech\/files\/2010\/03\/cooling5.gif\" alt=\"instanton\" align=\"left\" hspace=\"5\" \/><\/div>\n<p>Cooling Step 5 &#8211; Clusters of non-zero charge density and quark condensate are resolved.<\/p>\n<div style=\"clear: left;\"><\/div>\n<div class=\"alignleft\" style=\"clear: left; padding-right: 10px;\"><img src=\"https:\/\/www.bu.edu\/tech\/files\/2010\/03\/cooling10.gif\" alt=\"instanton\" align=\"left\" hspace=\"5\" \/><\/div>\n<p>Cooling Step 10 &#8211; Topological charge and chiral condensate begin to die out.<\/p>\n<div style=\"clear: left;\"><\/div>\n<div class=\"alignleft\" style=\"clear: left; padding-right: 10px;\"><img src=\"https:\/\/www.bu.edu\/tech\/files\/2010\/03\/cooling15.gif\" alt=\"instanton\" align=\"left\" hspace=\"5\" \/><\/div>\n<p>Cooling Step 15 &#8211; Topological charge and chiral condensate continue to die out and eventually vanish.<\/p>\n<div style=\"clear: left;\"><\/div>\n<h4>Paper<\/h4>\n<p><a href=\"https:\/\/www.bu.edu\/tech\/files\/2010\/03\/revised2z.ps\">revised2z.ps<\/a> with color images at <a href=\"https:\/\/www.bu.edu\/tech\/files\/2010\/03\/bilder.ps\">bilder.ps<\/a><\/p>\n<hr \/>\n<p><strong>Hardware:<\/strong> SGI Power Challenge Array and SGI Origin2000.<br \/>\n<strong>Software:<\/strong> Fortran 77, MPI. Visualization done with AVS.<br \/>\n<strong>Graphics programming and video production:<\/strong> Kathleen Curry, Scientific Computing and Visualization Group, Boston University.<br \/>\n<strong>Acknowledgments:<\/strong> T. Schafer and E. Shuryak for reviewing the 3-D images, E.M. Ilgenfritz, M. Muller and W. Sakuler for clarifying discussions. This work was partially supported by FWF.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Stefan Thurner Department of Electrical and Computer Engineering, Boston University M.C. Feurstein Department of Electrical and Computer Engineering, Boston University Institut fur Kernphysik, Vienna , Austria H. Markum Institut fur Kernphysik, Vienna , Austria There is a spring-like force in the vacuum existing between quarks that binds them together into observable bound states. Our research&#8230;<\/p>\n","protected":false},"author":1692,"featured_media":0,"parent":57322,"menu_order":47,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages\/3106"}],"collection":[{"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/users\/1692"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/comments?post=3106"}],"version-history":[{"count":13,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages\/3106\/revisions"}],"predecessor-version":[{"id":145649,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages\/3106\/revisions\/145649"}],"up":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/pages\/57322"}],"wp:attachment":[{"href":"https:\/\/www.bu.edu\/tech\/wp-json\/wp\/v2\/media?parent=3106"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}