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S. I. Bityukov

Publications and source records attributed to S. I. Bityukov.

29 records · Page 2Linked to original sources

Observability and Probability of Discovery in Future Experiments

We propose a method to estimate the probability of new physics discovery in future high energy physics experiments. Physics simulation gives both the average numbers $ $ of background and $ $ of signal events. We find that the proper definition of the significance is $S_{12} = \sqrt{ + } - \sqrt{ }$ in comparison with often used significances $S_1 = \displaystyle \frac{ }{\sqrt{ }}$ and $S_2 = \displaystyle \frac{ }{\sqrt{ + }}$. We propose a method for taking into account systematic uncertainties related to nonexact knowledge of background and signal cross sections. An account of such systematics is very essential in the search for supersymmetry at LHC. We propose a method for estimation of exclusion limits on new physics in future experiments. We also estimate the probability of new physics discovery in future experiments taking into account systematical errors.

hep-ph↗

Search for SUSY at LHC in Jets + E^{miss}_T final states for the case of nonuniversal gaugino masses

We investigate squark and gluino pair production at LHC (CMS) with subsequent decays into quarks and LSP for the case of nonuniversal gaugino masses. Visibility of signal by an excess over SM background in (n > 1)jets + E^{miss}_T events depends rather strongly on the relation between LSP, gluino and squark masses and it decreases with the increase of LSP mass. For relatively heavy LSP mass closed to squark or gluino masses and for (m_{\tilde{q}}, m_{\tilde{g}}) > 1.5 TeV signal is too small to be observable. For the case when only third generation squarks and LSP are relatively light signal is not visible without b-tagging.

hep-ph↗

Gaugino pair production at LHC for the case of nonuniversal gaugino masses

We investigate χ^{+/-}_1 χ^0_2 pair production at LHC (CMS) with subsequent decays into leptons for the case of nonuniversal gaugino masses. Visibility of signal by an excess over SM background in 3 leptons + no jet + E^{miss}_T events depends rather strongly on the relation between LSP mass χ^0_1 and χ^{+/-}_1 mass. We also give some preliminary results on the investigation of squark and gluino production at LHC for the case of nonuniversal gaugino masses.

hep-ph↗

New Physics Discovery Potential in Future Experiments

We propose a method to estimate the probability of new physics discovery in future high energy physics experiments. Physics simulation gives both the average numbers of background and of signal events. We find that the proper definition of the significance for , >> 1 is S_{12} = sqrt( + ) - sqrt( ) in comparison with often used significances S_1 = /sqrt( ) and S_2 = /sqrt( + ). We propose a method for taking into account the systematical errors related to nonexact knowledge of background and signal cross sections. An account of such systematics is very essential in the search for supersymmetry at LHC. We also propose a method for estimation of exclusion limits on new physics in future experiments.

physics.data-an↗

Study of eta pi- production by pions in the Coulomb field

The production of eta pi - system at low mass by the pi- beam in the Coulomb field of Be nuclei was studied. The cross section of the reaction pi- Be --> eta pi- Be was compared to the experimental data on the decay eta --> pi+ pi- gamma and to the theoretical predictions.

hep-ex↗

Gaugino pair production at LHC (CMS)

We investigate χ^{+/-}_1 χ^0_2 pair production at LHC (CMS) with subsequent decays into leptons for the case of nonuniversal gaugino masses. Visibility of signal by an excess over SM background in 3l + no jets + E^{miss}_T events depends rather strongly on the relation between LSP mass χ^0_1 and χ^{+/-}_1 mass.

hep-ph↗

On Observability of Signal over Background

Several statistics used by physicists to declare the signal observability over the background are compared. It is shown that the frequentist method of testing a precise hypothesis allows one to estimate the power value of criteria with specified level of significance for the considered statistics by Monte Carlo calculations. The application of this approach for the analysis of discovery potential of experiments is discussed.

physics.data-an↗

Towards the Observation of Signal over Background in Future Experiments

We propose a method to estimate the probability of new physics discovery in future high energy physics experiments. Physics simulation gives both the average numbers $ $ of background and $ $ of signal events. We find that the proper definition of the significance for $ , \gg 1$ is $S_{12} = \sqrt{ + } - \sqrt{ }$ in comparison with often used significances $S_1 = /\sqrt{ }$ and $S_2 = /\sqrt{ + }$. We also propose a method for taking into account the systematical errors related to nonexact knowledge of background and signal cross sections. An account of such systematics is very essential in the search for supersymmetry at LHC.

physics.data-an↗

The search for charged sleptons and flavour lepton number violation at LHC (CMS)

We study a possibility to detect charged sleptons and flavour lepton number violation at LHC (CMS). We investigate the production and decays of right- and left-handed sleptons separately. We have found that for luminosity L = 10**5 1/pb it would be possible to detect right-handed sleptons with a mass up to 325 GeV and left-handed ones with a mass up to 350 GeV. We also investigate a possibility to look for flavour lepton number violation in slepton decays due to the mixing of different slepton generations. We find that for the maximal (smu_R - se_R) mixing it is possible to detect such effect for sleptons with a mass up to 250 GeV.

hep-ph↗

The search for sleptons and flavour lepton number violation at LHC (CMS)

We study a possibility to detect sleptons and flavour lepton number violation at LHC (CMS). We investigate the production and decays of right- and left-handed sleptons separately. We have found that for L = 10**5 1/pb it would be possible to discover right-handed sleptons with a mass up to 350 GeV and left-handed ones with a mass up to 350 GeV. We also investigate a possibility to look for flavour lepton number violation in slepton decays due to the mixing of different generations sleptons. We find that for the maximal (smu_R - se_R) mixing it is possible to detect such effect for sleptons with a mass up to 250 GeV.

hep-ph↗

The search for new physics by the measurement of the 4-jet cross section at LHC and FNAL

We investigate the possibility to look for new physics by the measurement of the 4-jet cross section at LHC and FNAL. In particular, we consider the model with scalar colour octet and the supersymmetric model with R-parity violation. In both models pair produced new particles decay into 2 jets thus leading to 4-jet events. Therefore, the measurement of the distributions of 4-jet differential cross section on the invariant dijet masses allows to look for new physics. The main background comes from standard QCD 4-jet events. We find that at LHC it would be possible to discover scalar colour particles with masses up to 900 Gev and for FNAL the corresponding bound is 175 Gev.

hep-ph↗