Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: In search of superluminal quantum communications: recent experiments and
  possible improvements   As shown in the famous \emph{EPR} paper (Einstein, Podolsky e Rosen,1935),
Quantum Mechanics is non-local. The Bell theorem and the experiments by Aspect
and many others, ruled out the possibility of explaining quantum correlations
between entangled particles using local hidden variables models (except for
implausible combinations of loopholes). Some authors (Bell, Eberhard, Bohm and
Hiley) suggested that quantum correlations could be due to superluminal
communications (tachyons) that propagate isotropically with velocity
\emph{$v_{t}>c$} in a preferred reference frame. For finite values of
\emph{$v_{t}$}, Quantum Mechanics and superluminal models lead to different
predictions. Some years ago a Geneva group and our group did experiments on
entangled photons to evidence possible discrepancies between experimental
results and quantum predictions. Since no discrepancy was found, these
experiments established only lower bounds for the possible tachyon velocities
\emph{$v_{t}$}. Here we propose an improved experiment that should lead us to
explore a much larger range of possible tachyon velocities \emph{$v_{t}$} for
any possible direction of velocity $\vec{V}$ of the tachyons preferred frame.

0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org