Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Probe spectroscopy in an operating magneto-optical trap: the role of
  Raman transitions between discrete and continuum atomic states   We report on cw measurements of probe beam absorption and four-wave-mixing
spectra in a $^{85}$Rb magneto-optical trap taken while the trap is in
operation. The trapping beams are used as pump light. We concentrate on the
central feature of the spectra at small pump-probe detuning and attribute its
narrow resonant structures to the superposition of Raman transitions between
light-shifted sublevels of the ground atomic state and to atomic recoil
processes. These two contributions have different dependencies on trap
parameters and we show that the former is inhomogeneously broadened. The strong
dependence of the spectra on the probe-beam polarization indicates the
existence of large optical anisotropy of the cold-atom sample, which is
attributed to the recoil effects. We point out that the recoil-induced
resonances can be isolated from other contributions, making pump-probe
spectroscopy a highly sensitive diagnostic tool for atoms in a working MOT.

17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat