37 research outputs found

    Exotic ρ±ρ0\rho^\pm\rho^0 state photoproduction

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    It is shown that the list of unusual mesons planned for a careful study in photoproduction can be extended by the exotic states X±(1600)X^\pm(1600) with IG(JPC)=2+(2++)I^G(J ^{PC})=2^+(2^{++}) which should be looked for in the ρ±ρ0\rho^\pm\rho^0 decay channels in the reactions γNρ±ρ0N\gamma N\to\rho^\pm\rho^0N and γNρ±ρ0Δ\gamma N\to\rho^\pm \rho^0\Delta. The full classification of the ρ±ρ0\rho^\pm\rho^0 states by their quantum numbers is presented. A simple model for the spin structure of the γpf2(1270)p \gamma p\to f_2(1270)p, γpa20(1320)p\gamma p\to a^0_2(1320)p, and γNX±(N,Δ)\gamma N\to X^\pm (N, \Delta) reaction amplitudes is formulated and the tentative estimates of the corresponding cross sections at the incident photon energy Eγ6E_\gamma\approx 6 GeV are obtained: σ(γpf2(1270)p)0.12\sigma(\gamma p\to f_2(1270)p)\approx0.12 μ\mub, σ(γpa20(1320)p)0.25 \sigma(\gamma p\to a^0_2(1320)p)\approx0.25 μ\mub, σ(γNX±Nρ±ρ0N)0.018\sigma(\gamma N\to X^\pm N\to\rho^\pm\rho^0N)\approx0.018 μ\mub, and σ(γpXΔ++ρρ0Δ++)0.031\sigma(\gamma p\to X^-\Delta^{++ }\to\rho^-\rho^0\Delta^{++})\approx0.031 μ\mub. The problem of the X±X^\pm signal extraction from the natural background due to the other π±π0π+π\pi^\pm\pi^0 \pi^+\pi^- production channels is discussed. In particular the estimates are presented for the γph1(1170)π+n\gamma p\to h_1(1170)\pi^+n, γpρ+nπ+π0π+πn\gamma p\to\rho'^{+}n\to \pi^+\pi^0\pi^+\pi^-n, and γpωρ0p\gamma p\to\omega\rho^0p reaction cross sections. Our main conclusion is that the search for the exotic X±(2+(2++))X^\pm(2^+(2^{++})) states is quite feasible at JEFLAB facility. The expected yield of the γNX±Nρ±ρ0N\gamma N\to X^\pm N\to\rho^\pm\rho^0N events in a 30-day run at the 100% detection efficiency approximates 2.8×1062.8\times10^6 events.Comment: 19 pages, revtex, 1 figure in postscipt, some comments and references added, a few minor typos corrected, to be published in Phys. Rev.
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