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arXiv · hep-ex/9708030

Experimental determination of the b quark mass in DELPHI

S. Marti i Garcia·J. Fuster·S. cabrera
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Abstract

The running mass of the b quark as defined in the MS-bar renormalization scheme, m_b, was measured at the M_Z scale using 2.8 million hadronic Z^0 decays collected by the DELPHI experiment at LEP. The result is m_b(M_Z) = 2.67 +- 0.25 (stat.) +- 0.34 (frag.) +- 0.27(theo.) GeV/c^2 which differs from that obtained at the Upsilon scale, by m_b(M_Υ/2)-m_b(M_Z) = 1.49 +- 0.52 GeV/c^2. This measurement, performed far from the $b\bar{b}$ production threshold, provides the first experimental observation of the running of the quark masses.

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S. Marti i Garcia, J. Fuster, S. cabrera. 1997-08-20. Experimental determination of the b quark mass in DELPHI. https://doi.org/10.1016/s0920-5632(97)01092-x

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