In recent years , much effort has been devoted to unraveling the connection between the accretion flow and the jets in accreting compact objects .
In the present work , we report new constraints on these issues , through the long term study of the radio and X-ray behaviour of the black hole candidate H1743 - 322 .
This source is known to be one of the ‘ outliers ’ of the universal radio/X-ray correlation , i.e .
a group of accreting stellar-mass black holes displaying fainter radio emission for a given X-ray luminosity than expected from the correlation .
Our study shows that the radio and X-ray emission of H1743 - 322 are strongly correlated at high luminosity in the hard spectral state .
However , this correlation is unusually steep for a black hole X-ray binary : b \sim 1.4 ( with L _ { Radio } \propto L _ { X } ^ { b } ) .
Below a critical luminosity , the correlation becomes shallower until it rejoins the standard correlation with b \sim 0.6 .
Based on these results , we first show that the steep correlation can be explained if the inner accretion flow is radiatively efficient during the hard state , in contrast to what is usually assumed for black hole X-ray binaries in this spectral state .
The transition between the steep and the standard correlation would therefore reflect a change from a radiatively efficient to a radiatively inefficient accretion flow .
Finally , we investigate the possibility that the discrepancy between ‘ outliers ’ and ‘ standard ’ black holes arises from the outflow properties rather than from the accretion flow .