Measurements of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections in pp collisions at sqrt(s) = 7 TeV

The CMS collaboration
Phys.Lett.B 749 (2015) 14-34, 2015.

Abstract (data abstract)
CERN-LHC. Differential cross sections as a function of transverse momentum $p_\mathrm{T}$ are presented for the production of $\Upsilon(n\mathrm{S})$ ($n$ = 1, 2, 3) states decaying into a pair of muons. Data corresponding to an integrated luminosity of 4.9 fb$^{-1}$ in pp collisions at $\sqrt{s}$ = 7 TeV were collected with the CMS detector at the LHC. The analysis selects events with dimuon absolute rapidity $y$ lower than 1.2 and dimuon transverse momentum in the range of $p_\mathrm{T} $ between 10 and 100 GeV. The measurements show a transition from an exponential to a power-law behavior at $p_\mathrm{T} \approx 20$ GeV for the three $\Upsilon$ states. Above that transition, the $\Upsilon(3\mathrm{S})$ spectrum is significantly harder than that of the $\Upsilon(1\mathrm{S})$ and $\Upsilon(2\mathrm{S})$. The ratios of the $\Upsilon(3\mathrm{S})$ and $\Upsilon(2\mathrm{S})$ differential cross sections to the $\Upsilon(1\mathrm{S})$ cross section show a rise as $p_\mathrm{T}$ increases at low $p_\mathrm{T}$, then become flatter at higher $p_\mathrm{T}$ The tables below list the results of $\Upsilon$(1S), $\Upsilon$(2S) and $\Upsilon$(3S) differential cross sections (SIG) times dimuon branching fraction (B) in three rapidity bins, and ratios thereof. The $\Upsilon$(nS) polarizations measured by CMS are taken as input. The cross sections for different polarization scenarios may be obtained using the corresponding acceptance tables that are also provided below.

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