  We argue that $p_T$ distribution data from the LHC on the invariant
differential yield of the charged primary particles in $pp$ collisions at
$\sqrt{s}=0.9 TeV, 2.76 TeV,7TeV$ and in $Pb-Pb$ collisions at
$\sqrt{s_{NN}}=2.76 TeV$ with 6 centrality bins contains several $p_T$ regions
with special properties. These distributions were analysed by fitting the data
with exponential functions. We conclude that the regions reflect features of
fragmentation and hadronization of partons through the string dynamics. The
nuclear transparency results in negligible influence of the medium in the III
region ($p_T >17-20 GeV/c$), which has highest $p_T$ values. The effects and
changes by the medium start to appear weakly in the II region ($4-6 GeV/c <
p_T< 17-20 GeV/c$) and become stronger in the I region ($p_T <4-6 GeV/c$) . It
seems that the II region has highest number of strings. The increase in string
density in this region could lead to fusion of strings, appearance of a new
string and collective behaviour of the partons in the most central collisions.
These phenomena can explain anomalous behaviour of the Nuclear Modification
Factor in the II region. We propose the II region as a possible area of Quark
Gluon Plasma formation through string fusion. The first $p_T$ regions are the
ones with the maximum number of hadrons and minimum number of strings due to
direct hadronization of the low energy strings into two quark systems - mesons.
