b-hadron production at CMS

Two different analysis dedicated to the measurement of the $b$-quark production rate at the LHC are presented. For startup conditions ($\mathcal{L}$ = 50 pb$^{-1}$) and for a center of mass collision energy of 10 TeV, the $b\bar{b}$ differential cross section as function of the difference of azimuthal angles between the two $b$-quarks could be measured with a precision between 13\% and 17\% (depending on the bin) without using any $b$-tagging algorithm. For higher luminosities ($\mathcal{L}$ = 10 fb$^{-1}$) and for a center of mass collision energy of 14 TeV, the $b$-production rate could be measured up to a jet transverse momentum $p_\mathrm{T}$=1.5 TeV using the Combined Secondary Vertex $b$-tagging algorithm. For jets with $p_\mathrm{T}\approx 100$ GeV, the total uncertainty on the cross section measurement is below 20\%.