Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radiative lifetime measurements of rubidium Rydberg states   We have measured the radiative lifetimes of ns, np and nd Rydberg states of
rubidium in the range 28 < n < 45. To enable long-lived states to be measured,
our experiment uses slow-moving Rb atoms in a magneto-optical trap (MOT). Two
experimental techniques have been adopted to reduce random and systematic
errors. First, a narrow-bandwidth pulsed laser is used to excite the target
Rydberg state, resulting in minimal shot-to-shot variation in the initial state
population. Second, we monitor the target state population as a function of
time delay from the laser pulse using a short-duration, millimetre-wave pulse
that is resonant with a one- or two-photon transition. We then selectively
field ionize the monitor state, and detect the resulting electrons with a
micro-channel plate. This signal is an accurate mirror of the target state
population, and is uncontaminated by contributions from other states which are
populated by black body radiation. Our results are generally consistent with
other recent experimental results obtained using a less sensitive method, and
are also in excellent agreement with theory.

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The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an
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The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
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The categories of this paper are: nlin
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The categories of this paper are: stat
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The categories of this paper are: dg-ga
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
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The categories of this paper are: math
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The categories of this paper are: q-bio