Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Factorization in leptonic radiative B -> gamma e\nu decays   We discuss factorization in exclusive radiative leptonic B->\gamma e\nu
decays using the soft-collinear effective theory. The form factors describing
these decays can be expanded in a power series in Lambda/E_\gamma with E_\gamma
the photon energy. We write down the most general operators in the effective
theory which contribute to the form factors at leading order in
Lambda_QCD/E_\gamma, proving their factorization into hard, jet and soft
contributions, to all orders in alpha_s.

31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th