114 lines
5.3 KiB
TeX
114 lines
5.3 KiB
TeX
\documentclass[11pt,a4paper]{article}
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\usepackage[]{lmodern}
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\begin{document}
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\pagenumbering{gobble}% Remove page numbers (and reset to 1)
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\begin{center}
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\LARGE
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Statement of Research Interests\\
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% \large
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% Nam Tran
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\end{center}
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\bigskip
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My work centers in an experimental search for charged lepton flavor violation
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(CLFV) with muons, namely the COMET experiment at J-PARC. COMET is a new
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experiment that aims to find the neutrinoless decay of muon to electron in
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a nuclear field, or
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muon to electron conversion, at a single event sensitivity of $10^{-17}$. The
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experiment has high impact as a positive result would provide an unambiguous
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evidence of new physics beyond the Standard Model (BSM); and a negative result
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will place stringent limits on theoretical models. The search is part of the
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Intensity Frontier in particle physics, which will provide a window to probe
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physics at energy scales far beyond the reach of the most powerful accelerator
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currently exists. I was inspired to join the COMET experiment because of its
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elegance:
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\begin{itemize}
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\itemsep-0.5em
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\item the overall idea is simple;
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\item the signal is clean and distinctive;
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\item and many novel technologies and solutions are needed to realize its goal.
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\end{itemize}
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% One issue had arisen in the preparation for COMET experiment is our knowledge
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% on the products of the nuclear muon capture process on aluminum target was not
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% sufficient.
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One issue that arose during the preparation for COMET is that our knowledge of
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the products of the nuclear capture process on aluminum was not sufficient.
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Protons are expected to be a significant source of hits in the tracking
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detector of COMET, but there was no direct measurement of the proton rate and
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spectrum in the relevant energy range. Neutrons could cause serious problem for
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the front-end electronics. Therefore, COMET and its counterpart, Mu2e at
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Fermilab, jointly carried out a series of measurements, in the so-called AlCap
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experiment, of the products emitted after nuclear muon capture on aluminum and
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titanium at Paul Scherer Institute (PSI), Switzerland. I did a Monte Carlo
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study that showed the feasibility of the experiment, and contributed to DAQ
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developement, and hardware and electronics works on silicon and germanium
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detectors.
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My initial analysis of proton data in 2013 showed that the proton emission rate
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is low enough for the tracking detector of COMET to operate normally. The
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smallness of proton emission rate was later confirmed by another independent
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analysis on a larger dataset. However, there are still discrepancies between
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the two analyses. Therefore we have had another run for the proton measurement
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in 2015. The data analysis for this run is ongoing.
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Since November 2014, I have been assigned as a subproject leader of COMET,
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responsible for monitoring the number of muons that stop in the muon stopping
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target. The number is evidently necessary for calculation of branching ratio
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and single event sensitivity of the experiment. There have been several
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ideas on how to achieve the goal: online measurement of muonic X-rays and
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delayed gamma rays from activated $^{27}$Mg; measurement of the spectrum of
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decay-in-orbit electrons, and the rate of protons emitted after nuclear muon
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capture. I have proposed another activation measurement: measure population of
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a long-lived activation product, namely $^{24}$Na ($T_{1/2} = 14.96$~h). The
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measuring scheme will be:
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\begin{itemize}
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\itemsep-0.5em
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\item irradiation with muon beam for 2 days,
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\item beam off,
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\item measure delayed gammas from $^{24}$Na (1368 and 2574 keV) for 2 hours,
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\item continue irradiating, then repeat the cycle.
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\end{itemize}
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All these methods could be used simultaneously for cross-checking and
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reducing systematic uncertainties.
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% I also involve in other works, such as Monte Carlo simulation of cosmic ray
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% background in COMET Phase-I, and magnetic field map calculation for both COMET
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% Phase-I and Phase-II.
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Having been working in COMET for 5 years, I have been able to work together
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with great collaborators, and have gained a wide range of skills
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needed for an experimental physicist, including simulation, detector
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development, data acquisition, and data analysis. Now I would like to broaden
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my perspective and earn more experience by joining the Muon $g-2$ experiment.
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I am attracted by the ambitious goal of measuring the muon anomalous magnetic
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moment at an unprecedented precision, its impact of the measurement in
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establishing a signal for new physics beyond the Standard Model, as well as the
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synergy between $g-2$ and $\mu-e$ conversion experiments. My areas of
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contribution could be Monte Carlo simulation, detector and DAQ development.
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Besides, I am eager to learn new skills including accelerator-related
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techniques, FPGA development, and data analysis using machine learning.
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% moving to another position.
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% The
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% transition to Mu2e would be smooth since the two
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% experiments have many things in common.
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% Personally, I would like to strengthen
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% my data analysis skill with a new technique: machine learning. I believe
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% machine learning will be used extensively as I continue working in the
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% Intensity Frontier.
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\end{document}
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