  Following our earlier finding based on RHIC data on the dominant jet
production from nucleus corona region, we reconsider this effect in
nucleus-nucleus collisions at LHC energy. Our hypothesis was based on
experimental data, which raised the idea of a finite formation time for the
produced medium. At RHIC energy and in low density corona region this time
reaches about 2 fm/c. All observed high p_t particles are produced in the
corona region and have a chance to escape during this 2 fm/c. After that, the
formed high density matter absorbs all jets. Following this hypothesis, the
nuclear modification factor R_{AA} should be independent on particle momentum
and be flat versus p_t. At the same time, we describe the finite azimuthal
anisotropy of high p_t particles, v_2. A separate prediction held that, at LHC
energy, the formation time in the corona region should be two times smaller,
about 1 fm/c. New data at LHC show that R_{AA} is not flat and is rising with
p_t. We add to our original hypothesis an assumption that a fast parton
traversing the produced medium loses the fixed portion of its energy. A shift
of about 7 GeV (I would call it as a parton binding energy) from the original
power law p^{-6} production cross section in pp explains well all the observed
R_{AA} dependencies. The shift of about 7 GeV is also valid at RHIC energy,
where the cross section follows a power law with about p^{-8} and this shift
explains a very slow rise of R_{AA} seen for neutral pions with p_t above 15
GeV/c. We also show that the observed at LHC dependence of v_2 at high p_t and
our previous predictions agree.
