Light quark masses from scalar sum rules

In this work, the mass of the strange quark is calculated from QCD sum rules for the divergence of the strangeness-changing vector current. The phenomenological scalar spectral function which enters the sum rule is determined from our previous work on strangeness-changing scalar form factors [1]. For the running strange mass in the scheme, we find . Making use of this result and the light quark mass ratios obtained from chiral perturbation theory, we are also able to extract the masses of the lighter quarks and . We then obtain and . In addition, we present an updated value for the light quark condensate. Received: 18 October 2001 / Revised version: 22 January 2002 / Published online: 12 April 2002