  Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at $\sqrt{s_{_{\rm NN}}}$ = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in $|\eta|<0.8$ and $0.3 < p_T <
20$ GeV/$c$ are compared to the expectation in pp collisions at the same
$\sqrt{s_{\rm NN}}$, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor $R_{\rm AA}$. The result indicates only weak medium effects ($R_{\rm AA}
\approx $ 0.7) in peripheral collisions. In central collisions, $R_{\rm AA}$
reaches a minimum of about 0.14 at $p_{\rm T}=6$-7GeV/$c$ and increases
significantly at larger $p_{\rm T}$. The measured suppression of high-$p_{\rm
T}$ particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.
