  The properties of red clump giants in the central regions of the Galactic
bulge are investigated in the photometric $Z$ and $Y$ bands of the infrared VVV
(VISTA/ESO) survey and the [3.6],[4.5], [5.8] and [8.0] bands of the GLIMPSE
(Spitzer/IRAC) Galactic plane survey. The absolute magnitudes for objects of
this class have been determined in these bands for the first time: $M_{Z}=
-0.20\pm0.04$ and $M_{Y}=-0.470\pm0.045$, $M_{[3.6]}= -1.70\pm0.03$,
$M_{[4.5]}= -1.60\pm0.03$, $M_{[5.8]}= -1.67\pm0.03$ and $M_{[8.0]}=
-1.70\pm0.03$. A comparison of the measured magnitudes with the predictions of
theoretical models for the spectra of the objects under study has demonstrated
good mutual agreement and has allowed some important constraints to be obtained
for the properties of bulge red clump giants. In particular, a comparison with
evolutionary tracks has shown that we are dealing predominantly with the
high-metallicity subgroup of bulge red clump giants. Their metallicity is
slightly higher than has been thought previously, $[M/H]\simeq0.40$ (${\bf Z}
\simeq 0.038$) with an error of $[M/H]\simeq 0.1$ dex, while the effective
temperature is $4250\pm150$ K. Stars with an age of 9-10 Gyr are shown to
dominate among the red clump giants, although some number of younger objects
with an age of $\sim8$ can also be present. In addition, the distances to
several Galactic bulge regions have been measured, as D = 8200-8500 pc, and the
extinction law in these directions is shown to differ noticeably from the
standard one.
