a correction proportional to the particle mass both rising as powers of energy. The power like rise of mid rapidity density for charged (unidentified) particles has been confirmed up to the LHC energies [@:2009dt] and the leading power being 0.23 is in agreement with $2\lambda/(2+\lambda) \approx0.23$ for $\lambda=0.27$ [@McLerran:2010ex] . For large energies and small particle masses one can neglect the second term in Eq. (\[dNdy\]).

Constants $a_{\alpha}$ and $b_{\alpha}$ read:$$b_{\alpha}=\frac{1}{2+\lambda}%
%TCIMACRO{\dint }%
%BeginExpansion
{\displaystyle\int}
%EndExpansion
F_{\alpha}(\tau)\tau^{-\lambda/(2+\lambda)}d\tau,\;a_{\alpha}=\frac
{1}{2+\lambda}%
%TCIMACRO{\dint }%
%BeginExpansion
{\displaystyle\int}
%EndExpansion
F_{\alpha}(\tau)\tau^{-(\lambda+1)/(2+\lambda)}d\tau.\label{abalpha}%$$

We shall show now that GS leads also to the power-like dependence of the mean transverse momentum on the scattering energy. For massive particles we have:$$\begin{aligned}
p_{\text{T}}  & =Q_{0}\left(  \frac{W}{Q_{0}}\right)  ^{\lambda/(2+\lambda
)}\tau^{1/(2+\lambda)}\sqrt{1+2\frac{m_{\alpha}}{Q_{0}}\left(  \frac{W}{Q_{0}%
}\right)  ^{-\lambda/(2+\lambda)}\tau^{-1/(2+\lambda)}}.\end{aligned}$$ We see that for large energies the second term under the square root is suppressed (and also for small masses) so after expansion for large $W$ we obtain$$\begin{aligned}
p_{\text{T}}  & =Q_{0}\left(  \frac{W}{Q_{0}}\right)  ^{\lambda/(2+\lambda
)}\tau^{1/(2+\lambda)}+m_{\alpha}+ \ldots.\end{aligned}$$

We define mean transverse momentum as:$$\left\langle p_{\text{T}}\right\rangle =\frac{\frac{1}{2 Q_{0}^{2}}
%TCIMACRO{\dint }%
%BeginExpansion
{\displaystyle\int}
%EndExpansion
p_{\text{T}}F_{\alpha}(\tau)dp_{\text{T}}^{2}}{\frac{1}{2 Q_{0}^{2}}
%TCIMACRO{\dint }%
%BeginExpansion
{\displaystyle\int}
%EndExpansion
F_{\alpha}(\tau)dp_{\text{T}}^{2}}.\label{meanpt}%$$ Denominator of (\[meanpt\]) is given by Eq.(\[dNdy\]) whereas the numerator, after expanding in powers of $m_{\alpha}$ reads $$\begin{aligned}
\frac{\text{num.}}{Q_{0}}  & =\left(  \frac{W}{Q_{0}}\right)  ^{2\lambda
/(2+\lambda)}\left(  