Mini-review on QCD spectral sum rules

Abstract: Taking the example of the most popular and well-established Borel / Laplace / Exponential sum rule (LSR), I shortly review some of its recent applications in hadron physics namely the estimates of non-perturbative condensates, the determination of the light and heavy quark masses, the extraction of the heavy-light decay constants, the estimates of charmonium and bottomium molecule masses and the properties of scalar gluonium. In addition to the standard \tau (sum rule variable) and t_c (QCD continuum threshold) stablity criteria, I introduce a new stability criterion versus the arbitrary QCD subtraction point \mu for extracting the optimal results when radiative QCD corrections are included. Future improvements on further uses of QCD spectral sum rules (QSSR) are commented.