A. Taurok

Multifractal analysis of minimum bias events in\(\sqrt s \) = 630 GeV\(\bar p\)p collisions

A search for multifractal structures, in analogy with multifractal theories, is performed on UA1 minimum bias events. A downward concave multifractal spectral function,f(α) (where α is the Lipschitz-Hölder exponent), indicates that there are self-similar cascading processes, governing the evolution from the quark to the hadron level, in the final states of hadronic interactions.f(α) is an accurate measure of the bin to bin fluctuations of any observable. It is shown that the most sensitive comparison between data and the Monte Carlo models, GENCL and PYTHIA 4.8 can be made usingf(α). It is found that these models do not fully reproduce the behaviour of the data.

Measurement of the cross section ratio \sigma_{t\bar{t}b\bar{b}}/\sigma_{t\bar{t}jj} in pp collisions \sqrt{s}=8 TeV

The first measurement of the cross section ratio σ_(ttbb)/σ_(ttjj) is presented using a data sample corresponding to an integrated luminosity of 19.6 fb^(−1) collected in pp collisions at √s = 8TeV with the CMS detector at the LHC. Events with two leptons (e or μ) and four reconstructed jets, including two identified as b quark jets, in the final state are selected. The ratio is determined for a minimum jet transverse momentum pT of both 20 and 40 GeV/c. The measured ratio is 0.022 ± 0.003(stat) ± 0.005(syst) for pT > 20 GeV/c. The absolute cross sections σ_(ttbb) and σ_(ttjj) are also measured. The measured ratio for pT > 40 GeV/c is compatible with a theoretical quantum chromodynamics calculation at next-to-leading order.

Measurement of the ratio of the production cross sections times branching fractions of B_{c}^{\pm}\rightarrow J/\psi\pi^{\pm} and B^{\pm}\rightarrow J/\psi K^{\pm} and B(B_{c}^{\pm}\rightarrow J/\psi\pi^{\pm}\pi^{\pm}\pi^{\mp})/B(B_{c}^{\pm}\rightarrow J/\psi\pi^{\pm}) in pp collisions at \sqrt{s} =7 Tev

A bstractThe ratio of the production cross sections times branching fractions σBc±ℬBc±→J/ψπ±/σB±ℬB±→J/ψK±

Measurement of the ratio of the production cross sections times branching fractions of B c ± → J/ψπ ± and B± → J/ψK ± and \( \mathrm{\mathcal{B}}\left({\mathrm{B}}_{\mathrm{c}}^{\pm}\to \mathrm{J}/\psi {\pi}^{\pm }{\pi}^{\pm }{\pi}^{\mp}\right)/\mathrm{\mathcal{B}}\left({\mathrm{B}}_{\mathrm{c}}^{\pm}\to \mathrm{J}/\psi {\pi}^{\pm}\right) \) in pp collisions at \( \sqrt{s}=7 \) TeV

\left(\sigma \left({\mathrm{B}}_{\mathrm{c}}^{\pm}\right)\mathrm{\mathcal{B}}\left({\mathrm{B}}_{\mathrm{c}}^{\pm}\to \mathrm{J}/\psi {\pi}^{\pm}\right)\right)/\left(\sigma \left({\mathrm{B}}^{\pm}\right)\mathrm{\mathcal{B}}\left({\mathrm{B}}^{\pm}\to \mathrm{J}/\psi {K}^{\pm}\right)\right)

First Measurement of the Underlying Event Activity at the LHC with

is studied in proton-proton collisions at a center-of-mass energy of 7 TeV with the CMS detector at the LHC. The kinematic region investigated requires Bc± and B± mesons with transverse momentum pT > 15 GeV and rapidity |y| < 1.6. The data sample corresponds to an integrated luminosity of 5.1 fb−1. The ratio is determined to be 0.48±0.05stat±0.03syst±0.05τBc%