%% Title
%\titlepage[\vspace{5mm}Department of Physics,\\
%Graduate School of Science]%
%{A dissertation submitted to the Osaka University\\
%for the degree of Doctor of Philosophy}
\titlepage[]{\vspace{5mm}Department of Physics, Graduate School of Science\\
Osaka University}

%% Abstract
\begin{abstract}
  %[\smaller \thetitle\\ \vspace*{1cm} \smaller {\theauthor}]
  \thispagestyle{empty}
  COMET [1] is an experiment that aims to search for a charged lepton flavour
violation (CLFV) process, the muon-to-electron conversion in the presence of
a nucleus,
\muec. The process is forbidden in the Standard Model (SM), however is
predicted to occur in various extensions of SM. Current experimental
upper limit of the branching ratio is $BR(\mu^{-} + Au \rightarrow e^{-} + Au)
< 7 \times 10^{-13}$, set by the SINDRUM II experiment [2].

Using the J-PARC proton beam and the pion capture by
a solenoidal field, COMET will have a single event sensitivity  10,000 times
better than the current limit. The COMET collaboration has taken a phased
approach in which the first phase, COMET Phase-I [3], starts in 2013 and
initial data taking in around 2017. 

In order to optimize detector design for the Phase-I, backgrounds from nuclear
muon capture are crucial. We have proposed a dedicated experiment, namely
AlCap, at PSI, Switzerland to study the backgrounds, including protons,
neutrons and photons. The measurements of proton rate and spectrum on
aluminium have been carried out in the 2013 run. The second run to study
neutrons and photons is planned in 2015.

The preliminary results from the analysis of the 2013 run are presented in this
thesis. The measured proton spectrum peaks at \SI{3.7}{\MeV} and decays
exponentially with the decay constant of \SI{2.6}{\MeV}. The emission
rate of protons in the energy range from \SIrange{4}{8}{\MeV} is
$(1.7\pm0.1)\%$. The total proton emission rate is estimated to be
$(3.5\pm0.2)\%$ assuming the spectrum shape holds.
The resulted proton rate and spectrum were used to optimise the tracking
detector hit rate of the COMET Phase-I.

\end{abstract}


%% Declaration
\begin{declaration}
  \thispagestyle{empty}
  This dissertation is the result of my own work, except where explicit
  reference is made to the work of others, and has not been submitted
  for another qualification to this or any other university. 
  \vspace*{1cm}
  \begin{flushright}
    Nam Hoai Tran
  \end{flushright}
\end{declaration}


% Acknowledgements
\begin{acknowledgements}
  \thispagestyle{empty}
  First and foremost I would like to thank my supervisor Yoshitaka
  Kuno, for his great support and almost infinite patience in last four years.
  I am also grateful to  all members of the Kuno group, Department of
  Physics, Osaka University. Thanks to Akira Sato, Hideyuki Sakamoto for the
  knowledge and supervision they have provided. And to Takahisa Itahashi
  for the advice and allowing me to practice on his expensive silicon detectors.

  The measurement described in this thesis is the product of effort of all
  members of the AlCap Collaboration. Special thanks to Peter Kammel for
  always pushing the experiment forward and your very helpful advices.
  I enjoyed the stays at your group at University of Washington in Seattle
  a lot. I would also like to thank the
  fellow graduate students in the collaboration Andy, John, Ben, Damien for
  all the hard work in the beam time, in the analysis phase, and also for
  the beers. I wish you all success with your work.

  Finally, I would like to thank my family and friends. Without your love and
  support I wouldn't make it through these long years of graduate school.
\end{acknowledgements}


%% Preface
%\begin{preface}
  %\thispagestyle{empty}
  %The thesis is about measurements of products of nuclear muon capture on an
  %aluminium target, which is important for optimization of a tracking detector
  %of a search for muon to electron conversion, the E21 experiment - so called
  %COMET - at Japan Proton Accelerator Complex (J-PARC).
%\end{preface}

%% ToC
\tableofcontents


%% Strictly optional!
%\frontquote{%
	%Writing in English is the most ingenious torture\\
%ever devised for sins committed in previous lives.}%
%{James Joyce}
