Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Well-Tempered Neutralino   The dark-matter prediction is usually considered as one of the successes of
low-energy supersymmetry. We argue that, after LEP constraints are taken into
account, the correct prediction for the dark-matter density, at a quantitative
level, is no longer a natural consequence of supersymmetry, but it requires
special relations among parameters, highly sensitive to small variations. This
is analogous to the problem of electroweak-symmetry breaking, where the correct
value of the Z mass is obtained only with a certain degree of fine tuning. In
the general parameter space of low-energy supersymmetry, one of the most
plausible solution to reproduce the correct value of the dark-matter density is
the well-tempered neutralino, which corresponds to the boundary between a pure
Bino and a pure Higgsino or Wino. We study the properties of well-tempered
neutralinos and we propose a simple limit of split supersymmetry that realizes
this situation.

30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
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The categories of this paper are: nlin
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci