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%% Sample TeX file for the HRMS Dijon 2023 abstracts
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%% Lines (or parts of) beginning with at least one '%' are comments 
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%% Codings beginning with \ are LaTeX macros, or commands.
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%% Various informations about latex may be found at
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%%   http://en.wikibooks.org/wiki/LaTeX
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\documentclass[11pt]{article}

\usepackage{hrms}  %% Page settings, style ... for the HRMS abstract book.

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\title{TOWARDS A HYDROGEN MOLECULAR ION CLOCK}

%% Note that \author and \address macros must be paired.
%% The names of authors must also appear IN CAPITALS.
%% The name(s) of author(s) presenting the work is(are) usually underlined.

\author{\underline{\FirstName M. \LastName BEYER}}
\address{Department of Physics and Astronomy, VU Amsterdam, Amsterdam, The Netherlands.}

%% The \FirstName and \LastName macros are mandatory for each author
%% to make sure that the author index is properly auto-generated.
%% Otherwise, these macros do nothing in particular.

%% Add or remove \author and \address pair(s) below to suite your needs

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%% Place below other \usepackage{ ... }, if you need other packages.
%% See http://www.tug.org/texlive/doc.html for a description of available packages.

%% The macros below will change the page head and foot.
%% Please, do not modify the content of the \fancyhead macro nor the \fancyfoot line.
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhead[C]{{\footnotesize \textit{HRMS, 28th Colloquium, Dijon, France,
  Aug. 28 - Sept. 1, 2023}}}
\fancyfoot[C]{}
\renewcommand{\headrulewidth}{0.6pt}
\renewcommand{\footrulewidth}{0.6pt}

%% The hyperref package allows to include hyperlinks in a document.
%% See the instructions for abstract submission for more details.
%% WARNING: Make sure that this package comes LAST since it re-defines many LaTeX macros.
\usepackage[colorlinks=true,urlcolor=blue,linkcolor=blue,citecolor=blue]{hyperref}
\voffset -.65 cm

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\category {14,7}
\begin{document}

\maketitle  %% This will also build the list of author(s) and addresse(s).

%% Index macro(s): see the abstract samples and the instructions
%% Remove the %% to account for the index item(s)
%% \index{Item1}
%% \index{Item2}

%% Place the body of your abstract below.
The molecular hydrogen ion is the simplest of all molecules and as such is an important system for the development of molecular quantum mechanics. The rovibrational energy-level structure of this one-electron system can be calculated extremely precisely by quantum-chemical methods which include the determination of relativistic and QED effects. By comparison with the results of precision measurements of rovibronic intervals, fundamental constants, such as the proton-to-electron mass ratio, can be determined. 

I will give an overview of our work towards building a novel molecular clock based on weakly bound states of the molecular hydrogen ion. Various laser sources in the visible and (vacuum) ultraviolet wavelength range are used to selectively produce H$_2^+$ in the desired weakly bound states, and to precisely measure its 'clock' frequency in the microwave range. 

Together, the theoretical framework and results of the clock measurements form a unique system that will shed light on several intriguing pending issues in physics, ranging from the (still not understood) role of nuclear-spin-induced symmetry breaking within the framework of quantum electrodynamics, to the possible existence of time-varying fundamental constants and hypothesized spin-dependent fifth forces.  


\end{document}
