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Gamma strength functions (GSFs) and level densities (LDs) are essentialingredients of statistical nuclear reaction theory with many applications inastrophysics, reactor design, and waste transmutation. The aim of the presentwork is a test of systematic parametrizations of the GSF recommended by theRIPL-3 data base for the case of $^{208}$Pb. The upward GSF and LD in$^{208}$Pb are compared to gamma decay data from an Oslo-type experiment toexamine the validity of the Brink-Axel (BA) hypothesis. The E1 and M1 parts ofthe total GSF are determined from high-resolution forward angle inelasticproton scattering data taken at 295 MeV at RCNP, Osaka, Japan. The total LD in$^{208}$Pb is derived from the $1^-$ LD extracted with a fluctuation analysisin the energy region of the isovector giant dipole resonance. The E1 GSF iscompared to parametrizations recommended by the RIPL-3 data base showingsystematic deficiencies of all models in the energy region around neutronthreshold. The new data for the poorly known spinflip M1 resonance call for asubstantial revision of the model suggested in RIPL-3. The total GSF derivedfrom the present data is larger in the PDR energy region than the Oslo data butthe strong fluctuations due to the low LD resulting from the double shellclosure of $^{208}$Pb prevent a conclusion on a possible violation of the BAhypothesis. Using the parameters suggested by RIPL-3 for a description of theLD in $^{208}$Pb with the back-shifted Fermi gas model, remarkable agreementbetween the two experiments spanning a wide excitation energy range isobtained. Systematic parametrizations of the E1 and M1 GSF parts need to bereconsidered at low excitation energies. The good agreement of LD provides anindependent confirmation of the approach underlying the decomposition of GSFand LDs in Oslo-type experiments.

Gamma strength function and level density of $^{208}$Pb from forward-angle proton scattering at 295 MeV