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At least 307 records · Page 17

The primary composition beyond 10 to the 5th power GeV as deduced from high energy hadrons and muons in air showers

Data obtained from a large set of air shower simulation calculations with use of highly refined hadronic interaction and shower simulation model are presented, in an attempt to solve the problem of primary chemical composition beyond 100,000 GeV total energy. It is rated that high energy hadrons in air showers offer a rather unique primary mass signature and show that the interpretation of high energy muon data is much more ambiguous. Predictions are compared with experimental data.

Grieder, P. K. F.↗

Hadron thermodynamics in relativistic nuclear collisions

Various phenomenological models based on statistical thermodynamical considerations were used to fit the experimental data at high P sub T to a two temperature distribution. Whether this implies that the two temperatures belong to two different reaction mechanisms, or consequences of Lorentz-contraction factor, or related in a fundamental way to the intrinsic thermodynamics of Space-Time can only be revealed by further theoretical and experimental investigations of high P sub T phenomena in extremely energetic hadron-hadron collisions.

Ammiraju, P.↗

Angular distribution and multiplicity of backward hadrons in hFe interactions at 0.5-5.0 TeV energies (PION Experiment)

Based on the analysis of approximates 5 X 1000 events registered on the PION installation, data are obtained on the angular distribution and multiplicity of particles, flying back into the laboratory coordinate system (LCS) that are identified mainly as hadrons produced in the reactions of hFe yield h prime X type. The inclusively produced hadron energy is 200 MeV. The experimental data are compared to the results of the cumulative particle production in hA processes observed on accelerators at lower energies.

Avakian, V. V.↗

Experimental study of the space-time development of the particle production process in hadron-nucleon collisions, using massive target nucleus as a detector

Experimental study of the space-time development of the particle production process in hadronic collisions at its initial stage was performed. Massive target nuclei have been used as fine detectors of properties of the particle production process development within time intervals smaller than 10 to the 22nd power s and spatial distances smaller than 10 to the 12th power cm. In hadron-nucleon collisions, in particular in nucleon-nucleon collisions, the particle production process goes through intermediate objects in 2 yields 2 type endoergic reactions. The objects decay into commonly observed resonances and paricles.

Strugalski, Z.↗

Hadron intensity and energy spectrum at 4380 m above level

The flux value of hadrons with E (sup gamma) h or = 5 TeV, where E (sup gamma) h or = is the energy transferred into electromagnetic component is presented. It is shown that the energy spectrum slope beta of hadrons with E h or = 20 TeV is equal to 1.9.

Cananov, S. D.↗

Scaling violation in fragmentation region at energies above 10-15 eV based on the data on cosmic ray hadron component

The ratio of intensity of energetic hadrons, having no visible accompaniment, to the total flux of hadrons of the same energy at 4380m above sea level is given. The ratio is much more than expected for scaling model with proton primaries. This result could not be explained by complex chemical composition of primary cosmic ray and indicates the scaling violation in fragmentation region.

Source record↗

Lateral distribution of high energy hadrons and gamma ray in air shower cores observed with emulsion chambers

A high energy event of a bundle of electrons, gamma rays and hadronic gamma rays in an air shower core were observed. The bundles were detected with an emulsion chamber with thickness of 15 cm lead. This air shower is estimated to be initiated with a proton with energy around 10 to the 17th power to 10 to the 18th power eV at an altitude of around 100 gmc/2. Lateral distributions of the electromagnetic component with energy above 2 TeV and also the hadronic component of energy above 6 TeV of this air shower core were determined. Particles in the bundle are produced with process of the development of the nuclear cascade, the primary energy of each interaction in the cascade which produces these particles is unknown. To know the primary energy dependence of transverse momentum, the average products of energy and distance for various average energies of secondary particles are studied.

Matano, T.↗

Analysis of the hadron component in E.A.S.

Hadrons in extensive air showers (E.A.S.) provide direct information about high energy interactions. As a rule the biases pertaining to different shower array arrangements have a relative large influence for the basic phenomenological characteristics of the E.A.S. hadron component. In this situation, the problem of the correct comparison between model calculated and experimental characteristics is of great importance for the reliability of the derived conclusions about the high energy interaction characteristics.

Procureur, J.↗

High energy hadrons in extensive air showers

Experimental data on the high energy hadronic component in extensive air showers of energies approx. 10 to the 14 to 10 to the 16 eV when compared with expectations from Monte Carlo simulations have shown the observed showers to be deficient in high energy hadrons relative to simulated showers. An attempt is made to understand these anomalous features with more accurate comparison of observations with expectations, taking into account the details of the experimental system. Results obtained from this analysis and their implications for the high energy physics of particle interactions at energy approx. 10 to the 15 eV are presented.

Tonwar, S. C.↗

Electromagnetic and muonic structure of showers initiated by gamma-rays and by hadrons

If photon cascades develop by the usual mechanisms, there should indeed be notable differences between the structure of showers due to photon and hadron primaries, as regards muon densities and lateral distributions of some detector signals. The muon content of showers from Cygnus X-3, observed at Kiel, cannot be understood in this way. One remedy is to postulate arbitrarily a strong hadronic interaction of photons in the TeV region. This would utterly change the nature of electromagnetic cascades, but surprisingly does not at first sight seem to be in conflict with air shower observations.

Hillas, A. M.↗

Neutron stars as cosmic hadron physics laboratories

Extensive observations of Her-1 with the Exosat satellite have led to a new understanding of both the dynamics of neutron-star superfluids and the free precession of neutron stars. Detailed microscopic calculations on neutron matter and the properties of the pinned crustal superfluid are provided to serve as a basis for comparing theory with observation on neutron stars. Topics discussed include the Hadron matter equation of state, neutron star structure, Hadron superfluids, the vortex creep theory, Vela pulsar glitches, astrophysical constraints on neutron matter energy gaps, the 35 day periodicity of Her-1, and the neutron matter equation of state. It is concluded that since the post-glitch fits and the identification of the 35th periodicity in Her X-1 as stellar wobble require a rigid neutron matter equation of state, the astrophysical evidence for such an equation seems strong, as well as that for an intermediate Delta(rho) curve.

Pines, D.↗

Calculations of hadronic dissociation of Si-28 projectiles at 14.6A GeV by nucleon emission

An optical potential abrasion-ablation collision model is used to calculate hadronic dissociation cross sections for one, two, and three nucleon removal for the first time for a 14.6A GeV Si-28 beam fragmenting in aluminum, tin, and lead targets. These estimates are compared with recent semiinclusive measurements. Significant differences between some calculated and measured semiinclusive cross sections exist which cannot be resolved without measurements of the exclusive channel hadronic cross sections. Calculations for each exclusive reaction channel contributing to the semiinclusive cross sections are presented and discussed.

Townsend, Lawrence W.↗

Calculations of hadronic dissociation of 28Si projectiles at 14.6A GeV by nucleon emission

An optical potential abrasion-ablation collision model is used to calculate hadronic dissociation cross sections for one, two, and three nucleon removal for the first time for a 14.6A GeV 28Si beam fragmenting in aluminum, tin, and lead targets. These estimates are compared with recent semi-inclusive measurements. Significant differences between some calculated and measured semi-inclusive cross sections exist which cannot be resolved without measurements of the exclusive channel hadronic cross sections. Calculations for each exclusive reaction channel contributing to the semi-inclusive cross sections are presented and discussed.

NASA Program Radiation Health↗

Neutrino Emission in the Hadronic Synchrotron Mirror Model: The "Orphan" Flare from 1ES 1959+650

A challenge to standard leptonic synchrotron self-Compton (SSC) models is the so-called orphan TeV flares, i.e., enhanced very high energy (VHE) gamma-ray emission without any contemporaneous X-ray flaring activity, that have recently been observed in TeV blazars (e.g., 1ES 1959+650). In order to explain the orphan TeV flare of 1 ES 1959+650 observed in 2002 June, the so-called hadronic synchrotron mirror model has been developed. Here relativistic protons are proposed to exist in the jet and interact with reflected electron synchrotron radiation of the precursor SSC flare. If the reflector is located in the cloud region, time shifts of several days are possible between the precursor and the orphan flare. The external photons, blue-shifted in the comoving jet frame, are able to excite the Delta(1232) resonance when interacting with protons of Lorentz factors gamma(sub p) approx. 10(exp 3)-10(exp 4). The decay products of this resonance include charged pions, which, on decay, give rise to neutrino production during the orphan flare. In this paper we calculate the expected neutrino emission for the 2002 June 4 orphan TeV flare of 1ES 1959+650. We compare our results with the recent observations of AMANDA-II of a neutrino event in spatial and temporal coincidence with the orphan flare of this blazar. We find that the expected neutrino signal from the hadronic synchrotron mirror model is insufficient to explain the claimed neutrino signal from the direction of 1ES 1959+650.

Reimer, A.↗

A Forward Multiparticle Spectrometer for the LHC: Hadron spectra and Long-lived particle search

I describe a possible Forward Multiparticle Spectrometer (FMS) that could be installed downstream of the superconducting recombination dipole D1 in Run 4, from z = 96 m - 126 m to measure multi-TeV hadron spectra in low luminosity p + p collisions at Rt(s) = 14 TeV, as well as p + O and O + O collisions as relevant for cosmic ray showers. Light antinuclei and charmed hadrons at high Feynman xF can be measured, both of importance for astrophysics. At the full high luminosity HL-LHC a search for new long-lived neutral particles (LLPs) decaying in a 20 m long, 70 cm diameter vacuum pipe to visible decay modes (including gamma+gamma, e+e-, mu+mu-, tau+tau-, ccbar and jets) can be made. The FMS is especially well suited for LLPs with 1 GeV < M(X)< 10 GeV and lifetimes c.tau from about 10 m to several km. I discuss this as a possible addition to CMS but it has no formal approval yet, therefore the talk is not given on behalf of CMS.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

A BEAM SCREEN TO PREPARE THE RHIC VACUUM CHAMBER FOR EIC HADRON BEAMS: CONCEPTUAL DESIGN AND REQUIREMENTS

The Electron Ion Collider (EIC) Hadron Storage Ring (HSR) will use the existing Relativistic Heavy Ion Collider storage rings, including the superconducting magnet arcs [1]. The vacuum chambers in the superconducting magnets and the cold mass interconnects were not designed for EIC beams and so must be updated to reduce resistive-wall heating and to suppress e-clouds. To do so without compromising the EIC luminosity goal, a stainless steel beam screen with colaminated copper and a thin layer of amorphous carbon will be installed. This paper describes the main requirements that our solution for the hadron ring vacuum chamber needs to satisfy, including impedance, aperture limitations, vacuum, thermal and structural stability, mechanical design, installation and operation. The conceptual design of the beam screen currently under development is introduced.

43 PARTICLE ACCELERATORS↗

Future Circular Hadron Collider FCC-hh: Overview and Status

The Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. Its goal is to push the field to the next energy frontier beyond LHC, increasing by an order of magnitude the mass of particles that could be directly produced, and decreasing by an order of magnitude the subatomic distances to be studied. The FCC study covers two accelerators, namely, an energy-frontier hadron collider (FCC-hh) and a highest luminosity, high-energy lepton collider (FCC-ee). Both rings are hosted in the same 100 km tunnel infrastructure, replicating the CERN strategy for LEP and LHC, i.e. developing a lepton and a hadron ring sharing the same tunnel. This paper is devoted to the FCC-hh and summarizes the key features of the FCC-hh accelerator design, performance reach, and underlying technologies. The material presented in this paper builds on the conceptual design report published in 2019, and extends it, including also the progress made and the results achieved since then.

43 PARTICLE ACCELERATORS↗