Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Motivation for polarised $e^-$ and $e^+$ Beams   A future Linear Collider is well suited for discovering physics beyond the
Standard Model, for revealing the structure of the underlying physics as well
as for performing high precision tests of the Standard Model. The use of
polarised beams will be one of the powerful tools for reaching these goals.
This paper highlights some recent studies of having both beams simultaneously
polarised which allows to use longitudinally as well as transversely polarised
beams.

25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat