[en] We combine the fixed-order evaluation of the bb-bar sum rules with a non-relativistic effective-theory approach. The combined result for the nth moment includes all terms suppressed with respect to the leading-order result by O(α_s³) and O((α_s√(n))^lα_s²), counting α_s√(n)∼1. When compared to experimental data, the moments thus obtained show a remarkable consistency and allow for an analysis in the whole range 1≤n≤16

[en] The aim of this work is to look for how the muons in b-jets could be used to predict if the b-jet was initialized by b-quark or anti-b-quark. I have investigated the soft muons production mechanisms. I have optimized selection criteria from the view point of efficiency and purity. (authors)

No abstract available

No abstract available

[en] The discovery of a 125 GeV Higgs boson in July 2012 was a huge milestone for particle physics. While the properties of this particle agree with the predictions of the Standard Model (SM) at the current precision of measurements, it could well be only the first member of an extended Higgs sector. Different theoretical models, such as Supersymmetry and Compositeness, require additional Higgs bosons. This work focuses on the search for high mass Higgs bosons in final states with b-quarks. The analysis was performed with data collected by the CMS experiment at a center-of-mass energy of 13 TeV in the year 2016, corresponding to an integrated luminosity of 36.9 fb-1. The results are interpreted within models, including the Minimal Supersymmetric Standard Model.

[en] In this paper, we present an analysis of misidentification rate of secondary vertex b-tagging algorithm in the CDF experiment, which is used to distinguish b-jets from jets initiated by other quark flavors (u,d,c,s). The fraction of mis-tagged jets is determined using a technique of fitting template distributions of relative transverse momentum with respect to jet axis (p_T^rel) of soft muons in the jet to a distribution of aforementioned variable of muons from all b-tagged jets in data sample. We test the fraction fitting procedure on Monte Carlo sample by splitting it into two parts, where we treat one part as data and create template distributions from the other. Afterwards, we obtain the fraction of b and c-jets from fit on data sample of all b-tagged jets. The motivation for this study is the determination of forward-backward asymmetry in b bar b pair production. In order to obtain the asymmetry of signal (b bar b) only, one of the requirements is to determine the fraction of non-b quarks in the data. (authors)

[en] The aim of this work is to investigate the charge asymmetry in the production of b-bbar pairs in proton - proton collisions at the LHC at a centre energy of 8 TeV. The resulting quarks are hadronized, and therefore in the experiment we do not observe pairs of quarks, but showers of composite particles, i.e. hadrons (jets). The largest source of charge asymmetry is quark-antiquark annihilation. A Monte Carlo sample containing the second order of the perturbation theory, which corresponds to a non-zero value of charge asymmetry for b-bbar-pairs, was used for the analysis. (authors)

[en] The top quark is by far the heaviest particle in the Standard Model with a mass close to the scale of electroweak symmetry breaking. It is hence supposed to have the largest coupling to the Higgs-boson (called Yukawa coupling). This coupling can be directly measured in the associated production of a Higgs-boson with a top-quark pair. Due to the large mass of these particles, the process is strongly suppressed and has not been observed yet. The search presented here is performed in the lepton+jets channel of the t anti t decay, using the H → b anti b final state. This final state has large irreducible background from t anti tb anti b production and also large combinatorial background. The current status of the search will be presented using data collected at a centre-of-mass energy of 13 TeV with the ATLAS detector.

[en] The discovery of a 125 GeV Higgs boson in July 2012 was a huge milestone for particle physics. While the properties of this particle agree with the predictions of the Standard Model at the current precision of measurements, it could well be only the first member of an extended Higgs sector. Different theoretical models, such as Supersymmetry and Compositeness, require additional Higgs bosons. This work focuses on the search for such Higgs bosons in final states with b-quarks, corresponding to the strongest decay channel in minimal supersymmetric extension of the SM (MSSM) within the allowed parameter space. The status of first studies with data of the CMS experiment collected at a center-of-mass energy of 13 TeV is presented.

No abstract available