Contribution of disconnected diagrams to the hyperfine splitting of charmonium

TARO Collaboration; Philippe de Forcrand; Margarita García Pérez; Hideo Matsufuru; Atsushi Nakamura; Irina Pushkina; Ion-Olimpiu Stamatescu; Tetsuya Takaishi; Takashi Umeda

doi:10.1088/1126-6708/2004/08/004

arXiv · hep-lat/0404016

Contribution of disconnected diagrams to the hyperfine splitting of charmonium

TARO Collaboration·Philippe de Forcrand·Margarita García Pérez·Hideo Matsufuru·Atsushi Nakamura·Irina Pushkina·Ion-Olimpiu Stamatescu·Tetsuya Takaishi·Takashi Umeda

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Abstract

We discuss the contribution of OZI-suppressed diagrams to the hyperfine splitting of charmonium in lattice QCD. We study valence quark mass regions from strange to charm quark masses. No contribution of the disconnected diagram is seen in the vector meson channel. In the pseudo-scalar channel and for valence quark masses around the strange quark, the disconnected contribution induces a considerable increase of the meson mass. This contribution quickly decreases as the quark mass increases. For charmonium the effect is very small although a decrease of the pseudoscalar mass induced by the disconnected contribution cannot be ruled out.

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TARO Collaboration, Philippe de Forcrand, Margarita García Pérez, Hideo Matsufuru, Atsushi Nakamura, Irina Pushkina, Ion-Olimpiu Stamatescu, Tetsuya Takaishi, Takashi Umeda. 2004-08-17. Contribution of disconnected diagrams to the hyperfine splitting of charmonium. https://doi.org/10.1088/1126-6708%2F2004%2F08%2F004

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