Inelastic Distributions Research Articles

Probing quantum gravity with elastic interactions of ultrahigh-energy neutrinos

The next generation of radio telescopes will be sensitive to low-scale quantum gravity by measuring ultrahigh-energy neutrinos. In this work, we demonstrate for the first time that neutrino-nucleon soft interactions induced by TeV-scale gravity would significantly increase the number of events detected by the IceCube-Gen2 radio array in the EeV regime. However, we show that these experiments cannot measure the total cross section using only the angular and energy information of the neutrino flux, unless assumptions on the underlying inelasticity distribution of neutral interactions are made.

Analysis of nucleon-nucleus scattering data using a density-dependent semi-microscopic optical model with channel coupling

Background: The neutron scattering data was previously analyzed using a semi-microscopic optical model with channel coupling to inelastic excited states [Phys. Rev. C 100, 014603 (2019)]. The real part of the potential was constructed by single folding the density-independent M3Y-Paris bare nucleon-nucleon ($NN$) interaction, with zero-range knock-on exchange term, over the density of the target nucleus. The model reproduced the overall features of the inelastic angular distributions and polarization data. The elastic angular distributions were well reproduced.Purpose: In this work we test the effectiveness of the semi-microscopic optical model with channel coupling, but we employ a density-dependent BDM3Y1-Paris bare ($NN$) interaction, with the finite-range form of the knock-on exchange term, in describing the scattering observables, particularly, the inelastic distributions and polarization data.Method: The real volume term of the semi-microscopic model is constructed by single folding the density-dependent BDM3Y1-Paris bare ($NN$) interaction, over the matter distribution of the target nucleus. The ground state is coupled to low-lying inelastic excitation levels. The potential parameters are determined by fitting the elastic, inelastic, and polarization data corresponding to nucleon scattering off a wide range of mass numbers in the range $7\ensuremath{\le}A\ensuremath{\le}208$ for various energies from 10--95 MeV.Results: The density-dependent model resulted in significant improvements in the description of the inelastic angular distributions and analyzing power. In addition, the potential depths showed systematic linear dependence on incident energy, and one set of geometrical parameters is obtained for each nuclear target. We used our best-fit potential parameters to calculate the total cross sections corresponding to nucleon scattering off the considered nuclei. The calculated cross sections are in good agreement with the measured data.Conclusions: In a semi-microscopic optical model, construction of the real volume term by single folding the density-dependent BDM3Y1-Paris bare ($NN$) interaction, with finite form of the knock-on exchange term, results in significant improvements in reproducing the inelastic angular distributions and polarization data as compared to the case of using the density-independent M3Y-Paris bare nucleon-nucleon ($NN$) interaction, with either zero-range or finite-range exchange term.

Energy absorption and inelasticity distribution mechanisms in steel moment frames affected by mainshock-aftershock sequences

This study evaluates the effect of earthquake shock sequences on the collapse mechanism of Special Steel Moment Frames (SSMFs) by studying the distribution of plasticity and hysteretic energy parameters. For this purpose, four SSMFs with 4–20 stories are numerically modelled in OpenSees and subjected to incremental dynamic analysis (IDA). These analyses aim to capture the collapse state of structures under aftershock events preceded by various mainshock levels. The distribution of Maximum Ductility Demand (MDD) and Energy Absorption Contribution (EAC) at the collapse state is then evaluated in presence of sequential shocks. The results show that the EAC parameter provides better metric for studying the collapse mechanism which is remarkably affected by the mainshock-aftershock sequence. Accordingly, the role of elements experiencing damage under the mainshock becomes less prominent in absorbing the aftershock energy and is substituted by contribution of elements with less deterioration under the mainshock. The members’ EAC is also shown to be affected by the percentage of the energy imposed by each individual shock as a fraction of the total energy imposed by the mainshock-aftershock sequence. In overall, for low-rise structures subjected to aftershock-only excitation, almost equal EACs are provided by the beams and columns while beams’ EAC is shown to exceed 60% for high-rise structures due to their flexural load bearing mechanism. With introduction of the mainshock damage, however, the dependency of the EACs to the structures’ height becomes less significant.

Nuclear effects in high-energy neutrino interactions

Neutrino telescopes like IceCube, KM3NeT and Baikal-GVD offer physicists the opportunity to study neutrinos with energies far beyond the reach of terrestrial accelerators. These neutrinos are used to study high-energy neutrino interactions and to probe the Earth through absorption tomography. Current studies of TeV neutrinos use cross sections which are calculated for free nucleons with targets which are assumed to contain equal numbers of protons and neutrons. Here we consider modifications of high-energy neutrino interactions due to two nuclear effects: modifications of the parton densities in the nucleus, referred to here as shadowing, and the effect of non-isoscalar targets, with unequal numbers of neutrons and protons. Both these effects depend on the interaction medium. Because shadowing is larger for heavier nuclei, such as iron, found in the Earth's core, it introduces a zenith-angle dependent change in the absorption cross section. These modifications increase the cross sections by 1-2\% at energies below 100 TeV (antishadowing), and reduce it by 3-4\% at higher energies (shadowing). Nuclear effects also alter the inelasticity distribution of neutrino interactions in water/ice by increasing the number of low inelasticity interactions, with a larger effect for $\nu$ than $\bar\nu$. These effects are particularly large in the energy range below a few TeV. These effects could alter the cross sections inferred from events with tracks originating within the active detector volume as well as the ratio $\nu/\bar\nu$ inferred from inelasticity measurements. The uncertainties in these nuclear effects are larger than the uncertainties on the free-proton cross sections and will thus limit the systematic precision of future high-precision measurements at neutrino telescopes.

Measurements using the inelasticity distribution of multi-TeV neutrino interactions in IceCube

Inelasticity--the fraction of a neutrino's energy transferred to hadrons--is a quantity of interest in the study of astrophysical and atmospheric neutrino interactions at multi-TeV energies with IceCube. In this work, a sample of contained neutrino interactions in IceCube is obtained from 5 years of data and classified as 2650 tracks and 965 cascades. Tracks arise predominantly from charged-current $\nu_{\mu}$ interactions, and we demonstrate that we can reconstruct their energy and inelasticity. The inelasticity distribution is found to be consistent with the calculation of Cooper-Sarkar et al. across the energy range from $\sim$ 1 TeV to $\sim$ 100 TeV. Along with cascades from neutrinos of all flavors, we also perform a fit over the energy, zenith angle, and inelasticity distribution to characterize the flux of astrophysical and atmospheric neutrinos. The energy spectrum of diffuse astrophysical neutrinos is well-described by a power-law in both track and cascade samples, and a best-fit index $\gamma=2.62\pm0.07$ is found in the energy range from 3.5 TeV to 2.6 PeV. Limits are set on the astrophysical flavor composition that are compatible with a ratio of $\left(\frac{1}{3}:\frac{1}{3}:\frac{1}{3}\right)_{\oplus}$. Exploiting the distinct inelasticity distribution of $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ interactions, the atmospheric $\nu_{\mu}$ to $\bar{\nu}_{\mu}$ flux ratio in the energy range from 770 GeV to 21 TeV is found to be $0.77^{+0.44}_{-0.25}$ times the calculation by Honda et al. Lastly, the inelasticity distribution is also sensitive to neutrino charged-current charm production. The data are consistent with a leading-order calculation, with zero charm production excluded at $91\%$ confidence level. Future analyses of inelasticity distributions may probe new physics that affects neutrino interactions both in and beyond the Standard Model.

Performance‐based plastic design method for tall hybrid coupled walls

SummaryThe research presented herein involves a performance‐based design method for a tall hybrid coupled wall (HCW) system. For this study, HCW structures were designed with a performance‐based plastic design (PBPD) method. This approach directly accounts for inelastic structural behavior and considers design lateral force distribution at ultimate limit state. The design concept uses a pre‐selected target drift and yield mechanism as key performance limit states. The yield mechanism consists of shear yielding in the coupling beams and flexural yielding of reinforced concrete walls at the bases. HCW structures with varying heights and coupling ratios (CRs) were designed and subjected to a series of nonlinear dynamic analyses. The results indicated that the CR strongly influences the response of the structure. The structures could also be under‐designed when the inelastic distribution of lateral forces owing to higher modes was not properly considered. Finally, a design method to account for higher mode effects within the PBPD framework was presented. The method was validated using the results from nonlinear analyses. Copyright © 2016 John Wiley & Sons, Ltd.

Amplitude Characteristics of Inelasticity Distribution in Steel Kh18n10t Under High-Cycle Loading

The amplitude parameters of the statistical characteristics of inelasticity of the surface layer of steel Kh18N10T, which describe the kinetics of inelastic strain accumulation of the material structure under consideration at high-cycle fatigue, have been obtained. The features of variation of the statistical characteristics parameters of inelastic strains of the surface layer of the material specimen have been determined.

Energy-loss contribution to grazing scattering of fast He atoms from a silver surface

The energy lost by helium atoms axially scattered from a Ag(110) surface is studied in order to investigate the influence of dissipative processes on fast atom diffraction spectra. In this work inelastic projectile distributions are evaluated within a semiclassical formalism that includes dissipative effects due to electron-hole excitations through a friction force. For incidence along the $[1\overline{1}2]$ and $[1\overline{1}0]$ directions the model predicts the presence of multiple peaks in the energy-loss spectrum for a given impact energy. But these structures are completely washed out when the experimental dispersion of the incident beam is taken into account, giving rise to a smooth energy-loss distribution. Simulations including the experimental energy spread are in fairly good agreement with available experimental data for the $[1\overline{1}2]$ channel. In addition, our results suggest that inelastic processes produce an almost constant background in the transverse momentum distribution, except in the extremes of the momentum range where classical rainbow maxima appear. By adding elastic and inelastic contributions, experimental diffraction patterns are well reproduced.

A nonuniform TFA homogenization technique based on piecewise interpolation functions of the inelastic field

The present paper deals with a homogenization technique based on the Transformation Field Analysis (TFA) for the study of heterogeneous composite media characterized by nonlinear response. According to the TFA, the behavior of the representative volume element (RVE) is studied accounting for the nonlinear effects by means of the presence of a uniform inelastic strain distribution in the nonlinear constituent of the heterogeneous material. In order to improve the TFA, the assumption of uniformity of the inelastic strain distribution is removed, so that a nonuniform inelastic strain field, better representing the inelasticity distribution in the composite, is considered. In particular, the inelastic strain is represented as a piecewise linear combination of analytical functions of the spatial variable. The theory, presented in a general framework, can be successfully adopted for deriving the overall constitutive response for a wide range of nonlinear composite materials. Furthermore, the procedure is tailored to investigate the response of composites whose constituents are Shape Memory Alloys (SMA) and materials characterized by plastic behavior. Finally, numerical applications are developed in order to assess the effectiveness of the proposed nonuniform TFA procedure, comparing the results with the ones carried out performing Uniform and Piecewise Uniform TFA homogenizations and nonlinear finite element micromechanical analyses.

Inelastic Deformation of Extended Pile-Shafts

AbstractSeismic performance of extended pile-shafts depends not only on the intensity of the earthquake ground motion, but also on the pile structural properties and the soil conditions surrounding the pile. For assurance of good foundation performance, damage can be controlled by limiting the curvature ductility demand in the yielding region of the pile. However, curvature ductility demand is influenced by the strength and stiffness of the pile and the soil, and the ability of the soil-pile system to distribute the inelastic deformation in the pile. The pile curvature distribution can be written in the form of a nonlinear differential equation, including the effects of the pile yielding, soil nonlinearity, and secondary P-Δ moment arising from the axial load. A solution to the differential equation lends itself to the pile deflection, pile internal forces, soil pressure distribution, and, more importantly, the inelastic curvature distribution in the pile. The overall response in terms of a lateral force ...

Calculation of high energy neutrino-nucleon cross sections and uncertainties using the Martin-Stirling-Thorne-Watt parton distribution functions and implications for future experiments

We present a new calculation of the cross sections for charged current (CC) and neutral current (NC) $\nu N$ and $\bar{\nu} N$ interactions in the neutrino energy range $10^{4}<E_{\nu}<10^{12}$ GeV using the most recent MSTW parton distribution functions (PDFs), MSTW 2008. We also present the associated uncertainties propagated from the PDFs, as well as parametrizations of the cross section central values, their uncertainty bounds, and the inelasticity distributions for ease of use in Monte Carlo simulations. For the latter we only provide parametrizations for energies above $10^7$ GeV. Finally, we assess the feasibility of future neutrino experiments to constrain the $\nu N$ cross section in the ultra-high energy (UHE) regime using a technique that is independent of the flux spectrum of incident neutrinos. A significant deviation from the predicted Standard Model cross sections could be an indication of new physics, such as extra space-time dimensions, and we present expected constraints on such models as a function of the number of events observed in a future subterranean neutrino detector.

ReconcilingJ/ψProduction at HERA, RHIC, Tevatron, and LHC with Nonrelativistic QCD Factorization at Next-to-Leading Order

We calculate the cross section of inclusive direct J/ψ hadroproduction at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics, including the full relativistic corrections due to the intermediate 1S(0)[8], 3S(1)[8], and 3P(J)[8] color-octet states. We perform a combined fit of the color-octet long-distance matrix elements to the transverse-momentum (p(T)) distributions measured by CDF at the Fermilab Tevatron and H1 at DESY HERA and demonstrate that they also successfully describe the p(T) distributions from PHENIX at BNL RHIC and CMS at the CERN LHC as well as the photon-proton c.m. energy and (with worse agreement) the inelasticity distributions from H1. This provides a first rigorous test of nonrelativistic QCD factorization at next-to-leading order. In all experiments, the color-octet processes are shown to be indispensable.

Prospectives of the hadron program in ATLAS

One of the first measurements that will be made at the LHC by ATLAS deals with the properties of inelastic collisions, namely the central charged particle density and transverse momentum distributions. Current predictions of these distributions have large uncertainties in the LHC energy range. We describe the ATLAS minimum bias triggers, designed to select all kind of inelastic interactions, and the performance of the track reconstruction software which was adapted to soft particle track reconstruction. The precision with which the minimum bias distributions can be measured with early data is presented and the uncertainties on the inelastic distributions due to trigger bias is discussed.

Features of local inelasticity distribution in D16T aluminum alloy under static tensile conditions

We have assessed the characteristic of local inelasticity distribution, which controls the evolution of microstructural processes in a loaded surface layer of D16T structural aluminum alloy specimen in view of the strain-hardening stages and deformation mechanism changeover. The deformation stages for static tensile conditions are correlated with the characteristic of local inelasticity distribution, in order to determine the relationship between the deformation mechanism changeover and local inelasticity kinetics for the transition point from strain-hardening to strain-softening of the alloy under study.

Analytical model for transfer length prediction of 13 mm prestressing strand

An experimental investigation to determine the transfer length of a seven-wire prestressing strand in different concretes is presented in this paper. A testing technique based on the analysis of bond behaviour by means of measuring the force supported by the prestressing strand on a series of specimens with different embedment lengths has been used. An analytical bond model to calculate the transfer length from an inelastic bond stress distribution along the transfer length has been obtained. A relationship between the plastic bond stress for transfer length and the concrete compressive strength at the time of prestress transfer has been found. An equation to predict the average and both the lower bound and the upper bound values of transfer length is proposed. The experimental results have not only been compared with the theoretical prediction from proposed equations in the literature, but also with experimental results obtained by several researchers.

Magnetic Chiral Dichroism Studies using Energy Filtered Images

AbstractWe present the quantitative measurement of inelastic intensity distributions in diffraction patterns with the aim of studying magnetic materials. The original idea of using inelastic signal in a transmission electron microscope to measure magnetic information has been proposed recently by Schattschneider et al [1] and various experimental set-ups can be imagined [2,3]. We focus on a new experimental configuration which we use to acquire and collect a map of the signal with a high signal-to-noise ratio. We will also present the numerical treatments that need to be performed to get spatially accurate information and energy resolution. We will illustrate our method studying iron single crystal and discuss the effects of the drift and non-isochromaticity corrections.

Probing leptoquark production at IceCube

We emphasize the inelasticity distribution of events detected at the IceCube neutrino telescope as an important tool for revealing new physics. This is possible because the unique energy resolution at this facility allows to separately assign the energy fractions for emergent muons and taus in neutrino interactions. As a particular example, we explore the possibility of probing second and third generation leptoquark parameter space (coupling and mass). We show that production of leptoquarks with masses (greater-or-similar sign)250 GeV and diagonal generation couplings of O(1) can be directly tested if the cosmic neutrino flux is at the Waxman-Bahcall level.

Extended Gaussian ensemble or q-statistics in hadronic production processes?

The extended Gaussian ensemble introduced recently as a generalization of the canonical ensemble, which allows to treat energy fluctuations present in the system, is used to analyze the inelasticity distributions in high energy multiparticle production processes.

The Effect of Model Approximations on Single-Collision Distributions of Low-Energy Electrons in Liquid Water

The development of cross sections for the inelastic interaction of low-energy electrons with condensed tissue-like media is best accomplished within the framework of the dielectric theory. In this work we investigate the degree to which various model approximations, used in the above methodology, influence electron single-collision distributions. These distributions are of major importance to Monte Carlo track structure codes, namely, the energy-loss spectrum, the inelastic inverse mean free path, and the ionization efficiency. In particular, we make quantitative assessment of the influence of (1) the optical data set, (2) the dispersion algorithm, and (3) the perturbation and exchange Born corrections. It is shown that, although the shape and position of the energy-loss spectrum remains almost fixed, its peak height may vary by up to a factor of 1.5. Discrepancies in the calculated inelastic inverse mean free path are largely within 20-30% above 100 eV; they increase drastically, though, at lower energies. Exchange and perturbation Born corrections increase gradually below 1 keV leading to a approximately 30 to 40% reduction of the inverse mean free path at 100 eV. The perturbation effect contributes more than the exchange effect to this reduction. Similar to the dispersion situation, the effect of Born corrections at lower energies is also unclear since the models examined disagree strongly below 100 eV. In comparison, the vapor data are higher than the liquid calculations by 20 to 50% as the energy decreases from 1 to 0.1 keV, respectively. The excitation contribution is the main cause of this difference, since the ionization efficiency in the liquid levels off at approximately 90%, whereas the plateau value for the vapor is approximately 70%. It is concluded that electron inelastic distributions for liquid water, although in some respects distinctively different from the vapor phase, have associated uncertainties that are comparable in magnitude to the phase differences. The situation below 100 eV is uncertain.

Análise sobre a Inelasticidade nos Processos de Produção de Multipartículas nas Colisões Hadrônicas a Altas Energias.

This present work deals with a broad and critical phenomenological analysis about the inelasticity in the hadronic collisions at high energy levels. A discussion is presented with the purpose of correlating the inelasticity distributions with the multiplicity distribution as well as the characteristic functions of the impact parameter space. The energy dependence of the mean inelasticity is analyzed, based on the inclusive reactions of a particle and on the correlations with the probability of multiparticles distribution as well as with the inelastic overlapping function. In all attempts the results showed that the mean inelasticity remains constant in the GeV energy region. Finally, a way to examine the possibility of finding a broader connection among the inelasticity, the multiplicity and the impact parameter, is suggested.