Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: COW test of the weak equivalence principle: A low-energy window to look
  into the noncommutative structure of space-time?   We construct the quantum mechanical model of the COW experiment assuming that
the underlying space time has a granular structure, described by a canonical
noncommutative algebra of coordinates $x^{\mu}$. The time-space sector of the
algebra is shown to add a mass-dependent contribution to the gravitational
acceleration felt by neutron deBrogli waves measured in a COW experiment. This
makes time-space noncommutativity a potential candidate for an apparent
violation of WEP even if the ratio of the inertial mass $m_{i}$ and
gravitational mass $m_{g}$ is a universal constant. The latest experimental
result based on COW principle is shown to place an upper-bound several orders
of magnitude stronger than the existing one on the time-space noncommutative
parameter. We argue that the evidence of NC structure of space-time may be
found if the COW-type experiment can be repeated with several particle species.

20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg