Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electromagnetic form factor of the pion   The Standard Model prediction for the magnetic moment of the muon requires a
determination of the electromagnetic form factor of the pion at high precision.
It is shown that the recent progress in pi-pi scattering allows us to obtain an
accurate representation of this form factor on the basis of the data on e+e- ->
pi+ pi-. The same method also applies to the form factor of the weak vector
current, where the data on the decay tau -> pi- pi0 nu are relevant.
Unfortunately, however, the known sources of isospin breaking do not explain
the difference between the two results. The discrepancy implies that the
Standard Model prediction for the magnetic moment of the muon is currently
subject to a large uncertainty. Talk given in May 2002, in honor of Arkady
Vainshtein.

9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics