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Photoproduction of the Scalar Meson $f_0(500)$

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 Added by Hyun-Chul Kim
 Publication date 2015
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and research's language is English




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In the present talk, we report a recent investigation on photoproduction of the $gamma N to f_0(500)N$ within a framework of the effective Lagrangian. We include the nucleon resonances with pin $1/2$ in the $s$ channel. The coupling constants have been etermined by assuming that the decay process $N^* to (pipi)_{I=0,J=0}N$ can be regarded as $N^* to f_0(500) N$. We discuss the numerical results for the total cross sections and possible extension of the present work.



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The pion scalar form factor along with all existing S-wave iso-scalar $pipi$-scattering phase shift data in the elastic region up to $1 {rm GeV}^2$ are applied for a determination of the $f_0(500)$ and $f_0(980)$ meson parameters $m_{f_0(500)}=(360pm33){rm MeV}$, $Gamma_{f_0(500)}=(587pm 85){rm MeV}$ and $m_{f_0(980)}=(957pm77) {rm MeV}$, $Gamma_{f_0(980)}=(164pm142){rm MeV}$ in a model independent way.
We evaluated recent CLAS Collaboration measurements for the $90^circ$ meson photoproduction off the nucleon using a tagged photon beam spanning the energy interval $s = 3 - 11$ GeV$^2$. The results are compared with the Quark Counting Rules predictions.
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