Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fourth generation effects in the $B_s \to \nu \bar{\nu} \gamma$ decay   If the fourth generation fermions exist, the new quarks could influence the
branching ratio of the decay $B_s \to \nu \bar{\nu} \gamma$. We obtain two
solutions of the fourth generation CKM factor $V^*_{t's} V_{t'b}$ from the
decay of $B \to X_s \gamma$. With these two solutions we calculate the new
contributions of the fourth generation quark to Wilson coefficients of the
decay $B_s \to \nu \bar{\nu} \gamma$. The branching ratio of the decay $B_s \to
\nu \bar{\nu} \gamma$ in the two cases are calculated. In one case, our results
are quite different from that of SM, but almost same in another case. If a
fourth generation should exist in nature and nature chooses the former case,
this B meson decay could provide a possible test of the fourth generation
existence.

21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics