/usr/include/ql/experimental/models/ is in libquantlib0-dev 1.4-2+b1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ql/experimental/models/all.hpp
/usr/include/ql/experimental/models/atmadjustedsmilesection.hpp
/usr/include/ql/experimental/models/atmsmilesection.hpp
/usr/include/ql/experimental/models/basketgeneratingengine.hpp
/usr/include/ql/experimental/models/floatfloatswap.hpp
/usr/include/ql/experimental/models/floatfloatswaption.hpp
/usr/include/ql/experimental/models/gaussian1dcapfloorengine.hpp
/usr/include/ql/experimental/models/gaussian1dfloatfloatswaptionengine.hpp
/usr/include/ql/experimental/models/gaussian1djamshidianswaptionengine.hpp
/usr/include/ql/experimental/models/gaussian1dmodel.hpp
/usr/include/ql/experimental/models/gaussian1dnonstandardswaptionengine.hpp
/usr/include/ql/experimental/models/gaussian1dswaptionengine.hpp
/usr/include/ql/experimental/models/gsr.hpp
/usr/include/ql/experimental/models/gsrprocess.hpp
/usr/include/ql/experimental/models/kahalesmilesection.hpp
/usr/include/ql/experimental/models/markovfunctional.hpp
/usr/include/ql/experimental/models/mfstateprocess.hpp
/usr/include/ql/experimental/models/nonstandardswap.hpp
/usr/include/ql/experimental/models/nonstandardswaption.hpp
/usr/include/ql/experimental/models/smilesectionutils.hpp