  We present a study of transverse momentum ($p_{T}$) spectra of unidentified
charged particles in pp collisions at RHIC and LHC energies from $\sqrt{s}$ =
62.4 GeV to 13 TeV using Tsallis/Hagedorn function. The power law of
Tsallis/Hagedorn form gives excellent description of the hadron spectra in
$p_{T}$ range from 0.2 to 300 GeV/$c$. The power index $n$ of the $p_T$
distributions is found to follow a function of the type $a+b/\sqrt {s}$ with
asymptotic value $a = 5.72$. The parameter $T$ governing the soft bulk
contribution to the spectra remains almost same over wide range of collision
energies. We also provide a Tsallis/Hagedorn fit to the $p_{T}$ spectra of
hadrons in pPb and different centralities of PbPb collisions at $\sqrt{s_{NN}}$
= 5.02 TeV. The data/fit shows deviations from the Tsallis distribution which
become more pronounced as the system size increases. We suggest simple
modifications in the Tsallis/Hagedorn power law function and show that the
above deviations can be attributed to the transverse flow in low $p_T$ region
and to the in-medium energy loss in high $p_T$ region.
