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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Legendre analysis of differential distributions in hadronic reactions

Modern experimental facilities have provided a tremendous volume of reaction data, often with wide energy and angular coverage, and with increasing precision. For reactions with two hadrons in the final state, these data are often presented as multiple sets of panels, with angular distributions at numerous specific energies. Such presentations have limited visual appeal, and their physical content is typically extracted through some model-dependent treatment. Instead, we explore in this paper the use of a Legendre series expansion with a relatively small number of essential coefficients. This approach has been applied in several recent experimental investigations. Finally, we present some general properties of the Legendre coefficients in the helicity framework and consider what physical information can be extracted without any model-dependent assumptions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2014

Polarization phenomena in hadronic reactions

Predictions are made in the framework of the effective color field (ECF) model for polarization observables in p+A→ Λ-bar X, A + A → ΛX and p + Pb → pX reactions. The predictions can be checked in the polarization experiments at IHEP (SPASCHARM), JINR (NICA) and BNL (RHIC). Estimates of quark masses and anamolous chromomagnetic quark moments are given.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Cross sections of hadronic reactions e{sup +} e{sup −} → K{sup +} K{sup −} nπ (n =1,2,3) measured with the CMD3 detector at the VEPP-2000 electron-positron collider

We analyze the data on e{sup +} e{sup −} collisions at c.m.s. energies between 0.32 and 2 GeV collected in 2011–2013 with the CMD3 detector operating at the VEPP-3 e{sup +} e{sup −} collider of the Budker Institute of Nuclear Physics. The data correspond to an integrated luminosity of nearly 60 pb{sup -1}. Preliminary results e{sup +} e{sup −} → K{sup +} K{sup −} nπ (n = 1, 2, 3) on the reactions with two charged kaons in the final state are presented, and the procedure for estimating the integrated luminosity for each energy setting is described.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Single Target-Spin Asymmetries in Inclusive Hadron Electroproduction Reaction Using a Transversely Polarized 3He Target

Single-spin asymmetries (SSAs) are an invaluable tool to study the transverse-spin and transverse-momentum structure of the hadron. First measurements of transverse SSA were performed in pp??hX reactions in mid-70s followed by much more precise measurements from early 90s onwards. More recently transverse SSA were explored using semi-inclusive deep inelastic scattering (SIDIS) reactions using transversely polarized targets. A different type of reaction which is sensitive to transverse spin structure of nucleon, and experimentally least explored, is the inclusive hadron electroproduction on a transversely polarized nucleon (eN uparrow rightarrow hX). We report the first measurement of such SSAs, measured using a transversely polarized 3He target and the 5.9 GeV electron beam at Jefferson Lab. The Hall-A high-resolution spectrometer was used to detect hadrons (pi^pm,K^pm,p) which had an average hadron transverse momentum (pT) of 0.64 GeV/c. In this talk we will present the preliminary results of this experiment.

Allada, Kalyan↗
DOE OSTI2013

Reggeometry of lepton- and hadron-induced reactions

We append a simple Pomeron pole amplitude by t and Q{sup 2}, MV dependencies inspired by geometrical ideas. The experimentally transition from soft to hard dynamics is realized by the introduction of a two-component Pomeron with different Q{sup 2} and M{sub V}-dependent residues. A unified description of deeply virtual Compton scattering (DVCS), of exclusive electroproduction of all vector mesons as well as of elastic pp scattering is suggested.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Measurement of the π - -Ar total hadronic cross section at the LArIAT experiment

We present the first measurement of the negative pion total hadronic cross section on argon in a restricted phase space, which we performed at the Liquid Argon In A Testbeam (LArIAT) experiment. All hadronic reaction channels, as well as hadronic elastic interactions with scattering angle greater than 5° are included. The pions have kinetic energies in the range 100–700 MeV and are produced by a beam of charged particles impinging on a solid target at the Fermilab test beam facility. LArIAT employs a 0.24 ton active mass liquid argon time projection chamber (LArTPC) to measure the pion hadronic interactions. For this measurement, LArIAT has developed the “thin slice method,” a new technique to measure cross sections with LArTPCs. While moderately higher, our measurement of the π - -Ar total hadronic cross section is generally in agreement with the geant4 prediction.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

The Aerogel Cerenkov detector for the SHMS magnetic spectrometer in Hall C at Jefferson Lab

Hadronic reactions producing strange quarks such as exclusive or semi-inclusive kaon production, play an important role in studies of hadron structure and the dynamics that bind the most basic elements of nuclear physics. The small-angle capability of the new Super High Momentum Spectrometer (SHMS) in Hall C, coupled with its high momentum reach - up to the anticipated 11-GeV beam energy in Hall C - and coincidence capability with the well-understood High Momentum Spectrometer, will allow for probes of such hadron structure involving strangeness down to the smallest distance scales to date. To cleanly select the kaons, a threshold aerogel Cerenkov detector has been constructed for the SHMS. The detector consists of an aerogel tray followed by a diffusion box. Four trays for aerogel of nominal refractive indices of n =1.030, 1.020, 1.015 and 1.011 were constructed. The tray combination will allow for identification of kaons from 1 GeV/c up to 7.2 GeV/c, reaching 10 -2 proton and 10 -3 pion rejection, with kaon detection efficiency better than 95%. The diffusion box of the detector is equipped with 14 five-inch diameter photomultiplier tubes. Its interior walls are covered with Gore diffusive reflector, which is superior to the commonly used Millipore paper and improved the detector performance by 35%. The inner surface of the two aerogel trays with higher refractive index is covered with Millipore paper, however, those two trays with lower aerogel refractive index are again covered with Gore diffusive reflector for higher performance. The measured mean number of photoelectrons in saturation is ~12 for n =1.030, ~8 for n =1.020, ~10 for n =1.015, and ~5.5 for n =1.011. Here the design details, the results of component characterization, and initial performance tests and optimization of the detector are presented.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2012

QCD structure of matter

Dynamics of hadrons and nuclei are governed by the fundamental theory of strong interaction, the quantm chromodynamics (QCD). The current status of QCD and its applications to nuclear physics are reviewed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Hadronic cross sections, elastic slope and physical bounds

An almost model-independent parametrization for the ratio of the total hadronic cross section to elastic slope is discussed. Its applicability in studies of asymptotia and analyses of extensive air shower in cosmic-ray physics is also outlined.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Accounting for soft cross sections at the LHC

We describe briefly the elements of the GLM model that successfully describes soft hadronic interactions at energies from ISR to LHC. This model is based on a single Pomeron with a large intercept {Delta}{sub IP}= 0.23 and slope {alpha} Prime {sub IP}= 0, and so provides a natural matching with perturbative QCD. We summarize themain features and results of competing models for soft interactions at LHC energies.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

Modern hadron spectroscopy: a bridge between nuclear and particle physics

Here, in this talk I discuss aspects of hadron physics, which soon are expected to shed new light on the fundamental QCD phenomena. In the analysis of hadron reactions and their propertieds I emphasize similarities to the nuclear many body problem.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2012

High-momentum components of the nuclear wave function: Short range correlations, EMC effect, and the tensor parts of the N-N interaction

The combination of inclusive and exclusive electron scattering data from JLab in kinematic regimes that were not reachable before, together with the analysis and interpretation of older data from hadronic reactions at BNL is finally revealing the details of short-range nucleon-nucleon correlations in nuclei. The most significant result is the demonstration of the dominance of correlated np pairs over pp and nn pairs. I will review these results, discuss them in terms of short-range tensor-force dominance and also discuss the connection to the EMC effect.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2019

Electroweak probes of ground state densities

Background: Elastic electron scattering has been used for decades to paint the most accurate picture of the proton distribution in atomic nuclei. This stands in stark contrast to the neutron distribution that is traditionally probed using hadronic reactions that are hindered by large uncertainties in the reaction mechanism. Spurred by new experimental developments, it is now possible to gain valuable insights into the neutron distribution using exclusively electroweak probes. Purpose: In this work, we aim to assess the information content and complementarity of the following three electroweak experiments in constraining the neutron distribution of atomic nuclei: (a) parity-violating elastic electron scattering, (b) coherent elastic neutrino-nucleus scattering, and (c) elastic electron scattering of unstable nuclei. Methods: Relativistic mean-field models informed by the properties of finite nuclei and neutron stars are used to compute ground state densities and form factors of a variety of nuclei. All the models follow the same fitting protocol, except for the assumed—and presently unknown—value of the neutron skin thickness of 208 Pb. This enables one to tune the density dependence of the symmetry energy without compromising the success in reproducing well known physical observables. Results: We found that the ongoing PREX-II and upcoming CREX campaigns at Jefferson Lab will play a vital role in constraining the weak form factor of xenon and argon, liquid noble gases that are used for the detection of both neutrinos and dark matter particles. Conclusions: Remarkable new advances in experimental physics have opened a new window into ground state densities of atomic nuclei using solely electroweak probes. The diversity and versatility of these experiments reveal powerful correlations that impose important nuclear structure constraints. In turn, these constraints provide quantitative theoretical uncertainties that are instrumental in searches for new physics and insights into the behavior of dense matter.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗