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A.I. Pavlov

Bio: A.I. Pavlov is an academic researcher from Moscow State University. The author has contributed to research in topics: Physics & Type (model theory). The author has an hindex of 4, co-authored 7 publications receiving 564 citations.

Papers
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Journal ArticleDOI
01 Feb 1997
TL;DR: The reliability of model calculations is of considerable significance because at energies above those attained by accelerators only model predictions enable us to extract primary cosmic ray characteristics as discussed by the authors, which is of particular relevance in the case of EAS simulations.
Abstract: The reliability of model calculations is of considerable significance because at energies above those attained by accelerators only model predictions enable us to extract primary cosmic ray characteristics. Different phenomenological models based on the quark-gluon picture of hadron interactions are of use now as a foundation for experimental data analysis at energies > 10 15 eV. In this paper we consider the present status of quark-gluon string (QGS) model with allowance made for semihard processes and (in the framework of so advanced model) discuss experimental data obtained at energies 10 15 ÷ 10 19 eV. In doing so we assume mass composition following from the diffusion notions of cosmic ray propagation through the Galaxy. Some general problems of EAS simulation and among them the simulation of electron-photon cascades are also discussed.

515 citations

Journal ArticleDOI
TL;DR: In this paper, a new type of hadronic interaction model (NEXUS) is introduced, which has a much more solid theoretical basis than, for example, presently used models such as QGSJET and VENUS, and ensures therefore a much reliable extrapolation towards high energies.
Abstract: The purpose of this paper is twofold: first we want to introduce a new type of hadronic interaction model (NEXUS), which has a much more solid theoretical basis than, for example, presently used models such as QGSJET and VENUS, and ensures therefore a much more reliable extrapolation towards high energies. Secondly, we want to promote an extensive air shower (EAS) calculation scheme, based on cascade equations rather than explicit Monte Carlo simulations, which is very accurate in calculations of main EAS characteristics and extremely fast concerning computing time. We employ the NEXUS model to provide the necessary data on particle production in hadron-air collisions and present the average EAS characteristics for energies ${10}^{14}\ensuremath{-}{10}^{17}$ eV. The experimental data of the CASA-BLANCA group are analyzed in the framework of the new model.

42 citations

DOI
TL;DR: The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission described in this article was selected for flight to Venus as part of the NASA Discovery Program.
Abstract: The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission described herein has been selected for flight to Venus as part of the NASA Discovery Program. DAVINCI will be the first mission to Venus to incorporate science-driven flybys and an instrumented descent sphere into a unified architecture. The anticipated scientific outcome will be a new understanding of the atmosphere, surface, and evolutionary path of Venus as a possibly once-habitable planet and analog to hot terrestrial exoplanets. The primary mission design for DAVINCI as selected features a preferred launch in summer/fall 2029, two flybys in 2030, and descent-sphere atmospheric entry by the end of 2031. The in situ atmospheric descent phase subsequently delivers definitive chemical and isotopic composition of the Venus atmosphere during an atmospheric transect above Alpha Regio. These in situ investigations of the atmosphere and near-infrared (NIR) descent imaging of the surface will complement remote flyby observations of the dynamic atmosphere, cloud deck, and surface NIR emissivity. The overall mission yield will be at least 60 Gbits (compressed) new data about the atmosphere and near surface, as well as the first unique characterization of the deep atmosphere environment and chemistry, including trace gases, key stable isotopes, oxygen fugacity, constraints on local rock compositions, and topography of a tessera.

31 citations

Journal ArticleDOI
TL;DR: In this paper, experimental data on the EAS muon number fluctuations obtained with the Moscow State University EAS array are analyzed to derive the primary mass composition at energies before and after the knee.
Abstract: Experimental data on the EAS muon number fluctuations obtained with the Moscow State University EAS array are analysed to derive the primary mass composition at energies before and after the knee. The mass composition before the knee ( eV) corresponds to that measured by direct methods, while the mass composition after the knee ( eV) is enriched by heavy nuclei.

22 citations

Journal Article
TL;DR: In this article, the influence of the Landau-Pomeranchuk-Migdal (LPM) effect on the features of extensive air showers (EAS) was studied and the development of hadronic cascades was described in the quark-gluon string model.
Abstract: The influence of the Landau-Pomeranchuk-Migdal (LPM) effect on the features of extensive air showers (EAS) is studied. The development of hadronic cascades is described in the quark-gluon string model. It is shown that the LPM effect does not exert a significant influence on EAS features up to energies of 10{sup 20} eV. 19 refs., 2 figs.

7 citations


Cited by
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Journal ArticleDOI
Marcos Daniel Actis1, G. Agnetta2, Felix Aharonian3, A. G. Akhperjanian  +682 moreInstitutions (109)
TL;DR: The ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes as mentioned in this paper, which is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100GeV and above 100 TeV.
Abstract: Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.

1,006 citations

Journal ArticleDOI
G. L. Bayatian, S. Chatrchyan, G. Hmayakyan, Albert M. Sirunyan  +2060 moreInstitutions (143)
TL;DR: In this article, the authors present a detailed analysis of the performance of the Large Hadron Collider (CMS) at 14 TeV and compare it with the state-of-the-art analytical tools.
Abstract: CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider (LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking--through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start-up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb−1 or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, Bs production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb−1 to 30 fb−1. The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z0 boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing ET, B-mesons and τ's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model

973 citations

Journal ArticleDOI
TL;DR: In this article, the authors describe the changes required to the model to reproduce in detail the new data available from LHC and the consequences in the interpretation of these data, in particular the effect of the collective hadronization in p-p scattering.
Abstract: EPOS is a Monte-Carlo event generator for minimum bias hadronic interac- tions, used for both heavy ion interactions and cosmic ray air shower simulations. Since the last public release in 2009, the LHC experiments have provided a number of very inter- esting data sets comprising minimum bias p-p, p-Pb and Pb-Pb interactions. We describe the changes required to the model to reproduce in detail the new data available from LHC and the consequences in the interpretation of these data. In particular we discuss the effect of the collective hadronization in p-p scattering. A different parametrization of flow has been introduced in the case of a small volume with high density of thermalized matter (core) reached in p-p compared to large volume produced in heavy ion collisions. Both parametrizations depend only on the geometry and the amount of secondary particles en- tering in the core and not on the beam mass or energy. The transition between the two flow regimes can be tested with p-Pb data. EPOS LHC is able to reproduce all minimum bias results for all particles with transverse momentum from pt = 0 to a few GeV/c.

939 citations

Journal ArticleDOI
TL;DR: In this paper, the semi-inclusive reaction e(+)p -> e(+p) Xp was studied with the ZEUS detector at HERA with an integrated luminosity of 128 pb(-1) and the final-state proton carried a large fraction of the incoming proton energy, x(L) > 032, and its transverse momentum squared satisfied p(T)(2) <05GeV(2).
Abstract: The semi-inclusive reaction e(+)p -> e(+) Xp was studied with the ZEUS detector at HERA with an integrated luminosity of 128 pb(-1) The final-state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, x(L) > 032, and its transverse momentum squared satisfied p(T)(2) <05GeV(2); the exchanged photon virtuality, Q(2), was greater than 3 GeV2 and the range of the masses of the photon-proton system was 45

383 citations

Journal ArticleDOI
01 Jan 2006
TL;DR: The QGSJET model has been successfully used by different groups in the field of high energy cosmic rays as discussed by the authors, and the first general update of the model is devoted to the main improvement connected to an account for non-linear interaction effects which are of crucial importance for reliable model extrapolation into the ultra-high energy domain.
Abstract: Since a number of years the QGSJET model has been successfully used by different groups in the field of high energy cosmic rays. Current work is devoted to the first general update of the model. The key improvement is connected to an account for non-linear interaction effects which are of crucial importance for reliable model extrapolation into the ultra-high energy domain. The proposed formalism allows to obtain a consistent description of hadron-hadron cross sections and hadron structure functions and to treat non-linear effects explicitly in individual hadronic and nuclear collisions. Other ameliorations concern the treatment of low mass diffraction, employment of realistic nuclear density profiles, and re-calibration of model parameters using a wider set of accelerator data.

343 citations