%% file: TXSsymb.doc - Special Symbols - TeXsis version 2.18 %% @(#) $Id: TXSsymb.doc,v 18.2 2000/05/17 00:19:46 myers Exp $ %======================================================================* % (C) Copyright 1989, 1992, 1995, 1997 by Eric Myers and Frank E. Paige % This file is a part of TeXsis. Distribution and/or modifications % are allowed under the terms of the LaTeX Project Public License (LPPL). % See the file COPYING or ftp://ftp.texsis.org/texsis/LPPL %======================================================================* \ifx\undefined\meta \texsis\input TXSdocM.doc\input Manual.aux\draft\fi \subsection{Special Symbols \label{sect.symb}} \TeXsis\ defines some special symbols and other constructions which are not included in plain \TeX\ and which either are commonly used by physicists or are not trivial to construct. The following macros, which are listed here by related groups, provide these additional special symbols for use in equations: \index{symbols!physics} \bigskip \itemize \itm \CS{bra}\arg{text} and \CS{ket}\arg{text} produce the notations $\bra{\hbox{\it text}}$ and $\ket{\hbox{\it text}}$ respectively for quantum mechanical states. \CS{vev}\arg{text} produces $\vev{\hbox{\it text}}$ for a VEV (\idx{Vacuum Expectation Value}). \itm \CS{del}, \CS{grad}, and \CS{square} produce the notations $\del$, $\grad$, and $\square$ for various derivatives. (The first two are just synonyms for \cs{partial} and \cs{nabla}.) \itm \CS{degrees} is the degrees symbol. For example, |90\degrees| produces ``90\degrees''. You can use \CS{degree} as a synonym. These work equally well in math or text mode. \itm \CS{frac}\arg{numerator}\arg{denominator} produces the fraction |{|\ |\over| \|}|, while \hskip 0pt plus 6pt\CS{smallfrac}\arg{numerator}\arg{denominator} \hskip 0pt plus 6pt produces the same fraction in the smaller subscript style type. \CS{half} produces a $\half$ in a size appropriate to its usage. \itm \CS{simle} and \CS{simge} make the symbols $\simle$ and $\simge$ to indicate "less than about" and "greater than about," respectively. Synonyms for these are \CS{ltsim} and \CS{gtsim}. \itm \CS{parenbar} puts a bar in parentheses above a character; this is often used to indicate either a particle or its antiparticle. \CS{nunubar} and \CS{ppbar} are special cases. Thus \TeXexample $$ n \parenbar{n} \qquad \nu \nunubar \qquad p \ppbar $$ |endTeXexample gives $$ n \parenbar{n} \qquad \nu \nunubar \qquad p \ppbar $$ \goodbreak \itm \CS{subrightarrow}\arg{text} puts the text under a right arrow of the appropriate length. Thus \TeXexample $$ f(x) \subrightarrow{x \to 0} f(0) $$ |endTeXexample gives $$ f(x) \subrightarrow{x \to 0} f(0) $$ \itm \CS{buildchar}\arg{\#1}\arg{\#2}\arg{\#3} gives character |#1| with |#2| above it and |#3| below it, allowing the construction of a variety of special symbols. \CS{overcirc} is a special case of this which puts a small circle above a character, as in $\overcirc R$. This is often used in general relativity and related fields. \itm \CS{vbigl}\arg{delim}\arg{size} and \CS{vbigr}\arg{delim}\arg{size} produce very (or variably) big delimiters, generalizing the Plain \TeX\ macros \cs{bigl}, \cs{Bigr}, etc. They produce, respectively, the left and right delimiters \meta{delim} with height \meta{size}, which can be given in pt., cm., in., or any other valid units. Any valid delimiter may be used, but you must be careful if you use parentheses and automatic parenthesis sizing is also in effect (\Sect{paren}), because these conflict. You must either turn off automatic parenthesis sizing (with \cs{offparens}) or use \cs{lparen} or \cs{rparen} in place of `|(|' and `|)|'. \itm \CS{Leftcases}\arg{size} and \CS{Rightcases}\arg{size} give left and right braces of size \meta{size} smashed to zero height; these can be used in place of the \cs{cases} of Plain \TeX\ when it is desired to put an equation number on each line. For example, \TeXexample |smalltt$$\EQNalign{ m_e &= ~.511~\MeV \EQN lep;a \cr m_\mu &= ~105~\MeV \quad \Rightcases{50pt} \quad {\rm Leptons} \EQN lep;b \cr m_\tau &= 1784~\MeV \EQN lep;c \cr} $$ |endTeXexample gives\index{equations!alignment} $$\EQNalign{ m_e &= ~.511~\MeV \EQN lep;a \cr m_\mu &= ~105~\MeV \quad \Rightcases{50pt} \quad {\rm Leptons} \EQN lep;b \cr m_\tau &= 1784~\MeV \EQN lep;c \cr} $$ Note that |\Leftcases| and |\Rightcases| do not provide automatic spacing, which must be adjusted by the user as in the previous example. There seems to be no simple way to obtain automatic spacing and to allow an equation number on each line. \itm \CS{sterling} produces the British currency mark \sterling. \itm The astronomical symbols for the sun and the earth are \CS{sun} and \CS{earth}. For example, |$M_\sun$| and |$M_\earth$| give $M_\sun$ and $M_\earth$. You can also use them outside of math mode. \itm \CS{dimensions}\arg{units}\arg{power} is used for dimensional analysis. The units appear in square brackets, raised to the given power. For example to produce \dimensions{mass}{-3} you would type |\dimensions{mass}{-3}|. \itm \CS{slashchar}\arg{letter} puts a slash through a character, the notation for the contraction of a vector with Dirac $\gamma$ matrices in Feynman graphs. For example \TeXexample $$ {\cal L} = \bar\psi[i\slashchar{\partial} - e\slashchar{A}-m]\psi $$ |endTeXexample gives $$ {\cal L} = \bar\psi[i\slashchar{\partial} - e\slashchar{A}-m]\psi \,. $$ The results produced by |\slashchar| are not as good as one would like. You can do somewhat better by adjusting the kerning of the |/| by hand for each character. For example, \TeXexample \def\Aslash{A\kern -0.47em/} |endTeXexample \def\Aslash{A\kern -0.47em/}% produces ``$\Aslash$''. But note that the angle of the slash is still not quite what one would like for a slashed ``$A$.'' To really get good looking slashed characters someone will have to create a new slashed character math font using MetaFont. Meanwhile you can get by with |\slashchar| or define your own using kerning. \enditemize \bigskip\pagecheck{0.2\vsize} Abbreviations for units are normally set in Roman type even when used in formulas. Special function (e.g., sine, cosine and logarithm) or operator names are also set in Roman type, and \TeXsis\ adds some new names to go with the old standards. \itemize \itm \CS{Tr} and \CS{tr} give ``$\Tr$'' and ``$\tr$'' respectively for the trace of an operator or of a matrix. \CS{diag} is used to denote a diagonal matrix, as in $\eta_{\mu\nu}=\diag(-1,1,1,1)$. \itm \CS{real} and \CS{imag} give the symbols $\real$ and $\imag$ for the real and imaginary parts of an expression; the spacing is like that for any other function or operator. \itm \CS{eV}, \CS{keV}, \CS{MeV}, \CS{GeV}, and \CS{TeV} give the abbreviations for energy units $\eV$, $\keV$, $\MeV$, $\GeV$, and $\TeV$ respectively. \itm \CS{mb}, \CS{mub}, \CS{nb}, \CS{pb}, and \CS{fb} give the abbreviations for cross section units $\mb$, $\mub$, $\nb$, $\pb$, and $\fb$ respectively, while \CS{cmsec} gives $\cmsec$, the standard units for luminosity in colliding beam accelerators. \itm \CS{units}\arg{name} is a generic macro to print in Roman type the name of any units not covered by the macros above. For example, you can say \CS{units}|{furlongs}| and \CS{units}|{fortnights}| if you are using that particular system of units. \enditemize Note that all of the abbreviations for units above are defined without any spacing; to produce $$ {\cal L} = 10^{33}\,\cmsec, \qquad p_\perp = 8.3\,\GeV $$ you should type \TeXexample $$ {\cal L} = 10^{33}\,\cmsec, \qquad p_\perp = 8.3\,\GeV $$ |endTeXexample with a |\,| to make a thin space between the number and the units. %>>> EOF TXSsymb.doc <<<