<html> <head> <title>Top Processes</title> <link rel="stylesheet" type="text/css" href="pythia.css"/> <link rel="shortcut icon" href="pythia32.gif"/> </head> <body> <h2>Top Processes</h2> Different ways to produce top quarks, singly or in pairs. <p/><code>flag </code><strong> Top:all </strong> (<code>default = <strong>off</strong></code>)<br/> Common switch for the group of top production. <p/><code>flag </code><strong> Top:gg2ttbar </strong> (<code>default = <strong>off</strong></code>)<br/> Scatterings <i>g g → t tbar</i>. Code 601. <p/><code>flag </code><strong> Top:qqbar2ttbar </strong> (<code>default = <strong>off</strong></code>)<br/> Scatterings <i>q qbar → t tbar</i> by gluon exchange. Code 602. <p/><code>flag </code><strong> Top:qq2tq(t:W) </strong> (<code>default = <strong>off</strong></code>)<br/> Scatterings <i>q q' → t q''</i> by <i>t</i>-channel exchange of a <i>W^+-</i> boson. Code 603. <p/><code>flag </code><strong> Top:ffbar2ttbar(s:gmZ) </strong> (<code>default = <strong>off</strong></code>)<br/> Scatterings <i>f fbar → t tbar</i> by <i>s</i>-channel exchange of a <i>gamma^*/Z^0</i> boson. Code 604. <p/><code>flag </code><strong> Top:ffbar2tqbar(s:W) </strong> (<code>default = <strong>off</strong></code>)<br/> Scatterings <i>f fbar' → t q''</i> by <i>s</i>-channel exchange of a <i>W^+-</i> boson. Code 605. <p/><code>flag </code><strong> Top:gmgm2ttbar </strong> (<code>default = <strong>off</strong></code>)<br/> Scatterings <i>gamma gamma → t tbar</i>. Code 606. <p/> By default top always decays to a <i>W</i> and a down-type quark. It is possible to switch on the <i>t → H+ b</i> decay mode. Note that its partial width is calculated using the <i>tan(beta)</i> value stored in <code>HiggsHchg:tanBeta</code>, so that it can be used without having to read in a SUSY parameter file. For the <i>H+</i> to decay also <code>Higgs:useBSM = on</code> is necessary. </body> </html> <!-- Copyright (C) 2014 Torbjorn Sjostrand -->
