High-energy Interaction Models Research Articles

Strongly intensive variable in the model of high-energy pp interactions with the formation of string clusters

Strongly intensive variable in the model of high-energy pp interactions with the formation of string clusters

A multi-channel U-Matrix model of hadron interaction at high energy

The present phenomenological study investigates a multi-channel model of high-energy hadron interactions by considering a full parton configurations space and the U-matrix unitarisation scheme of the elastic amplitude, comparing it to the two-channel model, and examining the consequences of up-to-date high-energy collider data on the best fits to various hadronic observables in pp and poverline{p} collisions. The findings of this study reveal that the data are well-fitted with the multi-channel model and that the difference compared to the two-channel one is negligible. Of particular significance is the observation that the U-matrix unitarisation is likely incompatible with uncorrelated pomeron exchange, as suggested by the equivalence between the U-matrix multi-channel and eikonal two-channel descriptions. Based on our best fit, predictions for the ρ parameter, the double diffractive cross-section, and the elastic differential cross-section are provided. We shed light on the effect of taking into account a multi-channel model on present and future cosmic ray data.

EAS longitudinal development distribution parameters for different extrapolations of the nuclei intaraction cross section to the very high energy domain

Determination of the primary particle mass using air fluorescence or a Cherenkov detector array is one of the most difficult task of experimental cosmic ray studies. The information about the primary particle mass is a compound of the produced particle multiplicity, inelasticity, interaction cross-section and many other parameters, thus it is necessary to compare registered showers with sophisticated Monte-Carlo simulation results. In this work we present results of the studies of at least three possible ways of extrapolating proton- Nucleus and Nucleus-Nucleus cross sections to cosmic ray energies based on the Glauber theory. They are compared with experimental accelerator and cosmic ray data for the proton-air cross section. We also present results of the EAS development with the most popular high-energy interaction models adopted in the CORSIKA program with our cross section extrapolations. The average position of the shower maximum and the width of its distribution are compared with experimental data and some discussion is given.

The KASCADE Cosmic-ray Data Centre KCDC: granting open access to astroparticle physics research data

The ‘KASCADE Cosmic ray Data Centre’ is a web portal (https://kcdc.ikp.kit.edu), where the data of the astroparticle physics experiment KASCADE-Grande are made available for the interested public. The KASCADE experiment was a large-area detector for the measurement of high-energy cosmic rays via the detection of extensive air showers. The multi-detector installations KASCADE and its extension KASCADE-Grande stopped the active data acquisition in 2013 after more than 20 years of data taking. In several updates since our first release in 2013 with KCDC we provide the public measured and reconstructed parameters of more than 433 million air showers. In addition, KCDC provides meta data information and documentation to enable a user outside the community of experts to perform their own data analysis. Simulation data from three different high energy interaction models have been made available as well as a compilation of measured and published spectra from various experiments. In addition, detailed educational examples shall encourage high-school students and early stage researchers to learn about astroparticle physics, cosmic radiation as well as the handling of Big Data and about the sustainable and public provision of scientific data.

Measurement of the inelastic proton-proton cross section at sqrt{s}=13 TeV

A measurement of the inelastic proton-proton cross section with the CMS detector at a center-of-mass energy of sqrt{s}=13 TeV is presented. The analysis is based on events with energy deposits in the forward calorimeters, which cover pseudorapidities of −6.6 < η < −3.0 and +3.0 < η < +5.2. An inelastic cross section of 68.6 ± 0.5(syst) ± 1.6(lumi) mb is obtained for events with MX> 4.1 GeV and/or MY> 13 GeV, where MX and MY are the masses of the diffractive dissociation systems at negative and positive pseudorapidities, respectively. The results are compared with those from other experiments as well as to predictions from high-energy hadron-hadron interaction models.

Constraints on high energy interaction models from LHC and cosmic ray data

Predictions of popular cosmic ray interaction models for some basic character- istics of cosmic ray-induced extensive air showers are analyzed in view of experimental data on proton-proton collisions, obtained at the Large Hadron Collider. The differences between the results are traced down to different approaches for the treatment of hadronic interactions, implemented in those models. Potential measurements by LHC and cosmic ray experiments, which could be able to discriminate between the alternative approaches, are proposed. Modeling of high energy hadronic interactions is of considerable importance for experimental studies at the Large Hadron Collider (LHC) and, especially, in high energy cosmic ray (CR) field. In the latter case, one traditionally relies on the extensive air shower (EAS) techniques: the properties of primary CR particles are reconstructed from measured characteristics of nuclear-electro-magnetic cascades induced by CR interactions in the atmosphere. This naturally implies the importance of detailed Monte Carlo simulations of EAS development, particularly, of its backbone - the cascade of nuclear interactions of both the primary particles and of secondary hadrons produced. Thus, the success of the experimental studies depends on the validity of hadronic interaction models used in the analysis. One usually chooses between two main experimental procedures (1). In the first case, one deals with the information obtained with scintillation detectors positioned at ground. The energy of the pri- mary particle is reconstructed from the measured lateral density of charged particles (mostly electrons and positrons) while the particle type is inferred from the relative fraction of muons, compared to all charged particles at ground. Alternatively, one may study the longitudinal EAS development by mea- suring fluorescence light produced by excited air molecules at different heights in the atmosphere, for which purpose dedicated fluorescence telescopes are employed. The primary energy is then related to the total amount of fluorescence light emitted. In turn, the particle type may be determined from the measured position of the shower maximum Xmax - the depth in the atmosphere (in g/cm 2 )w here the number of ionizing particles reaches its maximal value. Not surprisingly, the observables used to determine the primary particle type - the lateral muon density ρμ and the EAS maximum position Xmax - appear to be very sensitive to details of high energy hadronic interactions. More precisely, Xmax depends strongly on the properties of the primary particle

Primary Cosmic Rays with Energies above 1015 eV – Rapporteur Review of Poster Presentations at the 23rd ECRS – Session PCR 2

Measurements of atmospheric Extensive Air Showers (EAS) are the only way of experimental studies of Primary Cosmic Rays (CR) with energies above 1015 eV. The final targets of these studies are search for astrophysical origin of these particles and properties of particle production in high energy particle interaction. Works presented at the PCR 2 session in the form of posters reflected the current progress in this area. In this review presented posters were grouped according to CR energy range, astrophysical significance, relation to high energy physics interaction properties and interaction models, and future experiments. 42 posters were submitted for this session. Some of the presented material in posters overlapped in parts with oral presentations.

All-particle energy spectrum of KASCADE-Grande based on shower size and different hadronic interaction models

KASCADE-Grande is a large detector array for observations of the energy spectrum as well as the chemical composition of cosmic ray air showers up to primary energies of 1 EeV. The multi-detector arrangement allows to measure the electromagnetic and muonic components for individual air showers. In this analysis, the reconstruction of the all-particle energy spectrum is based on the size spectra of the charged particle component. The energy is calibrated by using Monte Carlo simulations performed with CORSIKA and high-energy interaction models QGSJet, EPOS and SIBYLL. In all cases FLUKA has been used as low-energy interaction model. In this contribution the resulting spectra by means of different hadronic interaction models will be compared and discussed.

Influence of hadronic interaction models and the cosmic ray spectrum on the high-energy atmospheric muon and neutrino flux

The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A reviewed calculation of lepton spectra produced in cosmic ray induced extensive air showers is carried out with a primary cosmic ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to derive the inclusive differential spectra (yields) of muons, muon neutrinos and electron neutrinos at the surface for energies between 80 GeV and hundreds of PeV. Using these results the differential flux and the flavor ratios of leptons were calculated. The air shower simulator CORSIKA 6.990 was used for showering and propagation of the secondary particles through the atmosphere, employing the established high energy hadronic interaction models SIBYLL 2.1, QGSJet-01 and QGSJet-II-03. We show that the performance of the interaction models allows makes it possible to predict the spectra within experimental uncertainties, while SIBYLL generally yields a higher flux at the surface than the QGSJet models. The calculation of the flavor and charge ratios has lead to inconsistent results, mainly influenced by the different representations of the K/π ratio within the models. The influence of the knee of cosmic rays is reflected in the secondary spectra at energies between 100 and 200 TeV. Furthermore, we could quantify systematic uncertainties of atmospheric muon- and neutrino fluxes, associated to the models of the primary cosmic ray spectrum and the interaction models. For most recent parametrizations of the cosmic ray primary spectrum, atmospheric muons can be determined with an uncertainty smaller than +15/-13% of the average flux. Uncertainties of the muon and electron neutrino fluxes can be calculated within an average error of +32/-22% and +25/-19%, respectively. See the published paper [1].

Influence of hadronic interaction models and the cosmic ray spectrum on the high-energy atmospheric muon and neutrino flux

The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A reviewed calculation of lepton spectra produced in cosmic ray induced extensive air showers is carried out with a primary cosmic ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to derive the inclusive differential spectra (yields) of muons, muon neutrinos and electron neutrinos at the surface for energies between 80 GeV and hundreds of PeV. Using these results the differential flux and the flavor ratios of leptons were calculated. The air shower simulator CORSIKA 6.990 was used for showering and propagation of the secondary particles through the atmosphere, employing the established high energy hadronic interaction models SIBYLL 2.1, QGSJet-01 and QGSJet-II-03. We show that the performance of the interaction models allows makes it possible to predict the spectra within experimental uncertainties, while SIBYLL generally yields a higher flux at the surface than the QGSJet models. The calculation of the flavor and charge ratios has lead to inconsistent results, mainly influenced by the different representations of the K/π ratio within the models. The influence of the knee of cosmic rays is reflected in the secondary spectra at energies between 100 and 200 TeV. Furthermore, we could quantify systematic uncertainties of atmospheric muon- and neutrino fluxes, associated to the models of the primary cosmic ray spectrum and the interaction models. For most recent parametrizations of the cosmic ray primary spectrum, atmospheric muons can be determined with an uncertainty smaller than +15/-13% of the average flux. Uncertainties of the muon and electron neutrino fluxes can be calculated within an average error of +32/-22% and +25/-19%, respectively. See the published paper [1].

Influence of hadronic interaction models and the cosmic ray spectrum on the high energy atmospheric muon and neutrino flux

The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV have triggered a renewed interest into the high-energy interaction models and cosmic-ray primary composition. A reviewed calculation of lepton spectra produced in cosmic-ray-induced extensive air showers is carried out with a primary cosmic-ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to derive the inclusive differential spectra (yields) of muons, muon neutrinos and electron neutrinos at the surface for energies between 80 GeV and hundreds of PeV. Using these results, the differential flux and the flavor ratios of leptons were calculated. The air shower simulator CORSIKA 6.990 was used for showering and propagation of the secondary particles through the atmosphere, employing the established high-energy hadronic interaction models SIBYLL 2.1, QGSJet-01 and QGSJet-II-03. We show that the performance of the interaction models makes it possible to predict the spectra within experimental uncertainties, while SIBYLL generally yields a higher flux at the surface than the QGSJet models. The calculation of the flavor and charge ratios has lead to inconsistent results, mainly influenced by the different representations of the $K/\ensuremath{\pi}$ ratio within the models. The influence of the knee of cosmic rays is reflected in the secondary spectra at energies between 100 and 200 TeV. Furthermore, we could quantify systematic uncertainties of atmospheric muon and neutrino fluxes, associated to the models of the primary cosmic-ray spectrum and the interaction models. For most recent parametrizations of the cosmic-ray primary spectrum, atmospheric muons can be determined with an uncertainty smaller than $\genfrac{}{}{0}{}{+15}{\ensuremath{-}13}%$ of the average flux. Uncertainties of the muon and electron neutrino fluxes can be calculated within an average error of $\genfrac{}{}{0}{}{+32}{\ensuremath{-}22}%$ and $\genfrac{}{}{0}{}{+25}{\ensuremath{-}19}%$, respectively.

Shielding calculation for the Proton-Therapy-Center in Prague, Czech Republic

The study of radiation fields around the cyclotron room was carried out for the Proton-Therapy-Center in Prague (Czech Republic). The 230 MeV proton cyclotron will be installed there as well as additional components located along the beampath. The ambient doses were computed by taking into account 3 major sources of secondary radiation (neutron and photon) – the cyclotron, energy degrader and its collimator. The fluxes of neutrons/photons produced by protons were computed using Monte Carlo code MCNPXTM 2.5.0. Energy and angular distributions were computed for various targets and proton beam energies. Different physical models of high-energy proton interactions were studied as well. The annual charge at the cyclotron exit was based on the “patient model” (distribution of treatment type) established for a similar therapy center in Essen (Germany). Calculated data were used as an approximation of the radiation field of the most significant sources of radiation (graphite degrader, tantalum collimator). Fluence-to-dose conversion factors from ICRP-74 were used for the annual dose equivalent evaluation. With these results, the shielding analysis in the Therapy-Center was performed in the context of the current legislation requirements.

Two-scale hadronic structure and elasticppscattering: Predicted and measured

We update the comparison with experiment of the dynamical model of high-energy hadron interactions based on the two scale structure of hadrons. All predictions made over decade ago are confirmed with a high precision by the TOTEM experiment at LHC.

Search for astrophysical neutrinos in the Baikal neutrino project

The currently running NT200 and NT200+ Baikal neutrino telescopes and the prospects for development of the Baikal Neutrino Project are briefly descr⇊ed. Preliminary results of the search for neutrino events correlated with cosmological gamma-ray bursts at the NT200 are presented. The feasibility of developing a method for acoustic detection of ultrahigh-energy neutrinos in the Baikal Neutrino Project is discussed. The calculation results for the energy spectrum and zenith-angle distributions of atmospheric neutrinos in the energy range from 10 to 107 GeV obtained within various high-energy hadron-nucleus interaction models are presented.

Comparison of EAS simulation results using CORSIKA code for different high-energy interaction models

Interpretation of EAS characteristics for primary energy above the energy attained by man made accelerator is dominated by model predictions and detailed simulations. Differences and uncertainties in these hadronic interaction models play crucial role in the prediction of EAS characteristics. A comparative study for muon numbers to primary energy ratio and depth of shower maximum for different hadronic interaction models available in monte-carlo simulation code CORSIKA viz. QGSJET01, QGSJET-II, DPMJET, EPOS, SYBILL, and VENUS for two primaries (viz. proton and iron) in the energy range 10 14 eV to 10 17 eV is presented in this work.

Influence of low energy hadronic interactions on air-shower simulations

Experiments measuring cosmic rays above an energy of 10^14 eV deduce the energy and mass of the primary cosmic ray particles from air-shower simulations. We investigate the importance of hadronic interactions at low and high energies on the distributions of muons and electrons in showers on ground. In air shower simulation programs, hadronic interactions below an energy threshold in the range from 80 GeV to 500 GeV are simulated by low energy interaction models, like Fluka or Gheisha, and above that energy by high energy interaction models, e.g. Sibyll or QGJSJet. We find that the impact on shower development obtained by switching the transition energy from 80 GeV to 500 GeV is comparable to the difference obtained by switching between Fluka and Gheisha.

On minimum-bias effects at the LHC

In general, minimum-bias triggers planned for experiments at the LHC miss a considerable fraction of the total number of events. We exemplify the rejection rate using the Durham model of soft high-energy interactions to obtain quantitative estimates of the signals arising from the ATLAS scintillation counters positioned in the rapidity intervals 2<|η|<4, and also from TOTEM detectors covering the intervals 3.1<|η|<6.5. Typically we find that the expected signal is about half of the total cross section, σtot. We also calculate the cross section for the so-called zero-bias measurement planned by CMS in the extended rapidity interval −5<η<7. We emphasize that only models which give satisfactory predictions for the measured minimum-bias or zero-bias cross sections can be used to obtain the value of the total inelastic cross section.

Recent results from the Pierre Auger observatory

The Pierre Auger Observatory has been designed to measure cosmic rays above 1018 eV with unprecedented statistics and precision. After outlining why there is interest in such particles, recent measurements from the Observatory relating to the mass composition and energy spectrum above 1018 eV are described. From measurements of the variation of the depth of shower maximum with energy, there are indications - if models of high-energy interactions are correct - that the mass composition is not proton-dominated at the highest energies. A flattening of the slope of the energy spectrum from (-3.30 ± 0.06) to (-2.62 ± 0.02) is observed at 4.5 × 1018 eV while above 3.6 × 1019 eV the spectrum steepens to a slope of (-4.1 ± 0.4). Because of the composition result, caution needs to be exercised over interpretation of the steepening as the long-sought Greisen-Zatsepin-Kuzmin effect. The importance of data from the LHC for the more accurate interpretation of air-shower measurements is emphasised.

Recent results from the Pierre Auger Observatory—Including comparisons with data from AGASA and HiRes

The status of the Pierre Auger Observatory is described. Recent measurements from the Observatory relating to the arrival direction distribution, mass composition and energy spectrum above 1018eV are presented. No anisotropy has yet been detected. From measurements of the variation of the depth of shower maximum with energy, there are indications—if models of high-energy interactions are correct—that the mass composition is not proton dominated at the highest energies. A flattening of the slope of the energy spectrum from −3.30±0.06 to −2.62±0.02 is observed at 4.5×1018eV while above 3.6×1019eV the spectrum steepens with the slope becoming −4.1±0.4. Because of the composition result, caution needs to be observed over interpretation of the steepening as the long-sought Greisen–Zatsepin–Kuzmin effect. The results are discussed in the context of similar data from the AGASA and HiRes projects and are compared with some models for the propagation of high-energy cosmic rays.

Comparison of high energy interaction models used for atmospheric shower simulations above 1 TeV

We present here a comparison of interaction models commonly used for simulating cosmic ray shower development in the atmosphere at energies greater than 1 TeV. The implementations of these models in CORSIKA and the FLUKA transport and interaction code are relevant for extensive air shower experiments, neutrino telescopes, and gamma-ray surfacebased detectors. We compare the pion, kaon, charmed meson and baryon energy fractions and the multiplicities at the first interaction stage of monoenergetic protons on nitrogen nuclei in the range 1 TeV-100 PeV. We also show comparisons in terms of Z-moments, a spectrumweighted multiplicity often used in the cosmic ray community. The transverse and longitudinal momentum distributions of the secondary muons produced in proton-nitrogen collisions are also shown.