  We carried out a Subaru and UKIRT near infrared imaging survey for H-alpha
emitting galaxies around two pair quasar systems (Q0301-005/Q0302-003 and
Q2343+125/Q2344+125), and a triple quasar system (KP76/KP77/KP78). Narrow band
near infrared filters covering the H-alpha emission expected for galaxies at
the confirmed C IV absorption redshift toward the quasar systems were used for
this survey. These quasar pairs or triplet are separated at most by 17 arcmins
(~5 h^-1 Mpc in proper distance) from each other on the sky, and have common C
IV absorption lines at almost identical redshifts at z=2.24-2.43, which
suggests there could be a Mpc-scale absorbing systems such as a cluster, or a
group, of galaxies that cover all the line-of-sights to the pair/triple
quasars. Using narrow-band deep images, we detected five candidates for H-alpha
emitting galaxies around two of the six fields, Q2343+125 and Q2344+125, whose
apparent star formation rates are, extremely high, 20-466 M_solar/year.
However, all or most of them are not likely to be galaxies at the absorption
redshift but galaxies at lower redshift, because of their extreme brightness.
In the fields of the other quasars, we detected no star-forming galaxies, nor
did we find any number excess of galaxy counts around them. This no-detection
results could be because the luminosities and star formation rates of galaxies
are lower than the detection limits of our observations (K' > 21 and SFR <
1.8-240 h^-2 M_solar/year). They could be located outside of the observed
fields by chance. Otherwise, most C IV absorption lines could be ascribed not
to cluster of galaxies, but to isolated star forming pockets far from bright
galaxies and could be analogous objects to weak Mg II absorbers.
