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arXiv · 0907.3628

Estimate of the Branching Fraction of tau --> pi eta' nu_tau

Shmuel Nussinov·Abner Soffer
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Abstract

We calculate the expected branching fraction of the second-class-current decay tau --> pi eta' nu, motivated by a a recent experimental upper-limit determination of this quantity. The largest contribution to the branching fraction is due to the intermediate a0(980) scalar meson, assuming it is a $\bar ud$ state. Smaller contributions arise from a0(1450), rho(770), and rho(1450). Our calculated values are substantially below the experimental upper limit, and are smaller still if the a0(980) is a four-quark state, as often suggested. Thus, a precise measurement or tight upper limit has the potential to determine the nature of the a0(980), as well as search for new scalar interactions.

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Shmuel Nussinov, Abner Soffer. 2009-07-21. Estimate of the Branching Fraction of tau --> pi eta' nu_tau. https://doi.org/10.1103/physrevd.80.033010

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