The charged particle transverse momentum (pT) spectra are presented for pp
collisions at sqrt(s)=0.9 and 7 TeV. The data samples were collected with the
CMS detector at the LHC and correspond to integrated luminosities of 231
inverse microbarns and 2.96 inverse picobarns, respectively. Calorimeter-based
high-transverse-energy triggers are employed to enhance the statistical reach
of the high-pT measurements. The results are compared with both leading-order
QCD and with an empirical scaling of measurements at different collision
energies using the scaling variable xT = 2 pT/sqrt(s) over the pT range up to
200 GeV/c. Using a combination of xT scaling and direct interpolation at fixed
pT, a reference transverse momentum spectrum at sqrt(s)=2.76 TeV is
constructed, which can be used for studying high-pT particle suppression in the
dense QCD medium produced in heavy-ion collisions at that centre-of-mass
energy.
Research center :
AGIF - Algèbre, Géométrie et Interactions fondamentales
