2025MNRAS.541.2934C

We perform a comprehensive wide-band ($3\!-\!100$ keV) spectro-temporal analysis of 13 outbursting black hole X-ray binaries (BH-XRBs), utilizing data (quasi)simultaneous with radio observations, to unravel the complex disc-jet connection. RXTE observations are analysed for XTE J$1859+226$, GX $339-4$ (2002, 2006, and 2010 outbursts), 4U $1543-47$, H$1743-322$ (2003 and 2009 outbursts), XTE J$1550-564$, XTE J$1752-223$, XTE J$1650-500$, Swift J$1753.5-0127$, XTE J$1748-288$, and GRO J$1655-40$. For Swift J$1727.8-1613$ and MAXI J$1535-571$, we utilize HXMT data, while both AstroSat and HXMT observations are analysed for Swift J$1658.2-4242$. Type-C quasi-periodic oscillations (QPOs) observed in harder states (low hard state, hard intermediate state; $F_{nth} \ge 0.4$) exhibit positive lag for low-inclination sources ($i< 50^{\circ }$), whereas it generally exhibits negative lag for high-inclination sources ($i>60^{\circ }$), except XTE J$1550-564$, Swift J$1727.8-1613$, H$1743-322$ (2003 outburst), and GRO J$1655-40$. Notably, type-A QPOs exhibit negative lags ($\sim 1\!-\!10$ ms) regardless of source inclination, while type-B QPOs show positive lags in low-inclination sources, and both positive and negative lags ($\sim 1\!-\!15$ ms) in high-inclination sources, typically occurring in soft intermediate state (SIMS) ($F_{nth}\lesssim 0.45$). Systematic appearance of type-A QPOs preceding radio flares in several sources suggests that type-A QPOs indicate telltale signs of jet ejection, while type-B QPOs are closely linked with radio flares (i.e. transient jets). Present findings suggest the corona evolves from a radially extended to a vertically elongated structure during the type-C to type-B transition via type-A QPOs, with type-B QPOs linked to radially compact or vertically extended coronal geometries, resembling jet ejection. The strong radio-X-ray luminosity correlation seems to provide compelling evidence of accretion-powered jets. Finally, we find that jets in SIMS are moderately relativistic in nature with velocities $\gtrsim 0.3\!-\!0.8\, c$ in BH-XRBs under consideration.