Search for rare φ decays in π+π−γ final state

• Published in: Physics letters. B Vol. 415; no. 4; pp. 452 - 462
• Main Authors: Akhmetshin, R.R, Aksenov, G.A, Anashkin, E.V, Arpagaus, M, Astakhov, V.A, Baibusinov, B.O, Banzarov, V.S, Barkov, L.M, Bondar, A.E, Chernyak, D.V, Eidelman, S.I, Fedotovich, G.V, Gabyshev, N.I, Grebeniuk, A.A, Grigoriev, D.N, Ivanov, P.M, Khazin, B.I, Koop, I.A, Kurdadze, L.M, Kuzmin, A.S, Logashenko, I.B, Lukin, P.A, Lysenko, A.P, Maksimov, A.V, Merzlyakov, Yu.I, Nesterenko, I.N, Okhapkin, V.S, Perevedentsev, E.A, Popkov, E.V, Purlatz, T.A, Root, N.I, Ruban, A.A, Ryskulov, N.M, Shubin, M.A, Shwartz, B.A, Sidorov, V.A, Skrinsky, A.N, Smakhtin, V.P, Snopkov, I.G, Solodov, E.P, Sukhanov, A.I, Titov, V.M, Yudin, Yu.V, Brown, D.H, Roberts, B.L, Thompson, J.A, Valine, C.M, Hughes, V.W
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25-12-1997
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/S0370-2693(97)01365-8

A search for
φ radiative decays has been performed using a data sample of about 2.0 million
φ decays collected by the CMD-2 detector at VEPP-2M collider in Novosibirsk. From the selected
e
+
e
−→
π
+
π
−
γ events the following results were obtained:
B(
φ→
f
0(980)
γ)<1×10
−4 for destructive and
B(
φ→
f
0(980)
γ)<7×10
−4 for constructive interference with the Bremsstrahlung process respectively,
B(
φ→
γ→
π
+
π
−
γ)<3×10
−5 for
E
γ
>20 MeV,
B(
φ→
ργ)<7×10
−4. From the selected
e
+
e
−→
μ
+
μ
−
γ events
B(
φ→
μ
+
μ
−
γ)=(2.3±1.0)×10
−5 has been obtained for
E
γ
>20 MeV. The upper limit on the P,CP-violating decay
η→
π
+
π
− has also been placed:
B(
η→
π
+
π
−)<9×10
−4. All upper limits are at 90% C.L.