# How to typeset the symbols for charged particles?

Maybe this question will seem trivial, but I was wondering how you people typeset symbols for charged particles? I was thinking here in particular about the electron, the proton and the neutron. This is how I do them:

$e^-$
$p^+$
$n^0$


This looks pretty good imho, but maybe you have another favourite (or more scientific) way of doing it?

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NIST's guide for the use of SI recommends (on page 35) that "symbols representing purely descriptive terms (for example, the chemical elements) are roman". This would most likely apply to subatomic particles as well. To do this, I would use \mathrm:

$\mathrm{e^-}$, $\mathrm{p^+}$, $\mathrm{n^0}$.


Of course, that looks like it might get tedious, so I'd probably define macros for them:

\newcommand\elec{\mathrm{e^-}}
\newcommand\prot{\mathrm{p^+}}
\newcommand\neut{\mathrm{n^0}}


which would allow you to quickly and universally change them if you decided that some other typesetting convention was better.

Personally, I'd prefer sans-serif, but then I'm no chemist or particle physicist.

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Definitely the way to go: The IUPAP's Red Book lists the symbols for the elementary particles in Table 3 on p. 11 and explicitly states that "the symbol e (roman) for the electron should not be confused with the symbol e (italic) for the elementary charge" and "The charge of the particle may be indicated by adding a superscript +, 0, - to the symbol for the particle". I wouldn't recommend mixing serif and sans-serif, though. – Jake Oct 5 '11 at 0:51
Looks like I've been doing it wrong all this time. Thanks for the heads-up, Niel, Jake. – Richard Terrett Oct 5 '11 at 9:10
My reasons for wanting to use sans-serif (which, bear in mind, has no basis in what is the correct standard) is precisely that I would want to set certain symbols apart from both the surrounding prose and the surrounding math. In certain communities of computer scientists, it has become a convention to typeset complexity classes this way, e.g. \mathsf{P} \ne \mathsf{NP}. I feel a bit of a bias towards typesetting a certain type of formal symbol in this way. If it meant that my math or prose became riddled with frequent switches between roman and sans-serif, maybe I'd feel differently. – Niel de Beaudrap Oct 5 '11 at 10:08
If you don't have to follow a particular style, I'd say that you can choose what you like better. I have read books (some, albeit, 50-60 years old) which do it either way. And my own preference would be the italic style: $e^-$. – Andrey Vihrov Oct 5 '11 at 14:05
I would add \ensuremath to the commands your proposed to avoid writing extra \$. – Artem Pelenitsyn Oct 8 '11 at 15:50

As a chemist, I'd agree on how the particles should look (upright font, matching the surroundings). I'd use mhchem to achieve this

\documentclass{article}
\usepackage[version=3]{mhchem}
\begin{document}
\ce{n^0} \ce{e-} \ce{p+}
\end{document}

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As an alternative to Joseph's suggestion, mhchem, there is also the chemmacros package with a very similar command. It also provides some shortcuts (to be used both in text mode and math mode) for some common particle symbols and allows you to define your own, too. chemmacros' tries to follow IUPAC's recommendations which also recommend upright letters for particles:

\documentclass{article}
\usepackage{chemmacros}[2014/01/24]
% let chemmacros' use upright greek letters:
\usepackage{upgreek}
\begin{document}

\ch{e-} \ch{p+} \ch{n^0} \ch{\chembeta-} \ch{\chembeta+}