Origins of the energy distribution structure in coherent pion production at intermediate energies

2001 ◽  
Vol 79 (8) ◽  
pp. 1055-1074 ◽  
Author(s):  
P A Deutchman
Keyword(s):  
Incident Energy ◽  
Giant Resonance ◽  
Intermediate Energy ◽  
Hole State ◽  
Energy Distributions ◽  
Intermediate Energies ◽  
Pion Energy ◽  
Three Body ◽  
Energy Dependent ◽  
First Time

New calculations have been done that now cover the intermediate energy range from 100 MeV/nucleon to 2.0 GeV/nucleon incident energy for the reaction 12C + 12C [Formula: see text] 12C + 12C (15.11 MeV) +π0, where constructive, coherent Δ-hole states are excited in either nucleus while the companion nucleus is excited to a coherent nucleon–hole state describing the spin–isospin, giant resonant state at 15.11 MeV. The Δ (1232 MeV) isobar then decays to a nucleon and pion. Theoretical pion energy distributions are calculated and, for the first time, results above 400 MeV/nucleon are shown. A theoretical basis for understanding how the shapes of the pion distributions change as a function of incident energy is described. The fundamental shape of the Δ-production amplitude as a function of momentum transfer is discussed and the effects of the energy-dependent nuclear width are examined. Furthermore, the connection between the origins of the pion distribution to the final pion shapes is made and the importance of the giant resonance in providing an important signature is pointed out. By pushing the calculations above 400 MeV/nucleon, it was discovered that sliding kinematics and kinematic turnarounds occur due to the two-to-three-body sequential nature of the reactions and these effects determine the final structure of the pion distributions at higher incident energies. PACS Nos.: 24.10Cn, 24.30Cz, 25.70-z, 25.80-e

Identical nuclei in coherent pion production at intermediate energies

2002 ◽  
Vol 80 (9) ◽  
pp. 941-950
Author(s):  
P A Deutchman
Keyword(s):  
Forward Direction ◽  
Intermediate Energy ◽  
Initial State ◽  
Energy Distributions ◽  
Final State ◽  
Intermediate Energies ◽  
Body State ◽  
Pion Energy ◽  
Three Body ◽  
First Time

The formalism for the calculation of constructive, coherent production of pions through the collision of intermediate-energy nuclei now includes for the first time the exchange symmetry due to identical nuclei both in the initial two-body state and in the final three-body state. Of the eight terms that contribute to the pion-energy distributions, four of the amplitudes are equal in pairs, effectively leaving four amplitudes with direct terms in the initial state and direct and exchange terms in the final state. Of these remaining amplitudes, the final-state exchange terms are negligible as far as the calculation is concerned. This holds for pion-energy distributions over the incident energies from 100 MeV/nucleon to 2 GeV/nucleon for pions fixed in the forward direction (θπ = 0°) and the projectile and target, respectively, fixed in the fore and aft directions. This work is also generalized to include schematic solutions for the cases of identical nuclei in the initial state only, identical nuclei in the final state only, and the case of no identical nuclei at all. PACS Nos.: 24.10Cn, 24.30Cz, 25.70-z, 25.80-e

scholarly journals A New Energy-dependent Δ Width in Coherent Pion Production

1999 ◽  
Vol 52 (6) ◽  
pp. 955 ◽  
Author(s):  
P. A. Deutchman
Keyword(s):  
Form Factor ◽  
Pion Production ◽  
Bound State ◽  
Momentum Dependence ◽  
Energy Distributions ◽  
Particle Decay ◽  
Pion Energy ◽  
New Energy ◽  
Vertex Form Factor ◽  
Energy Dependent

A new derivation for the energy-dependent Δ width inside nuclei is presented which includes the all important, energy-dependent nuclear form factor describing the decay of the Δ particle from its harmonic oscillator, bound state back to a captured nucleon and outgoing pion. Additional improvements include relativistic kinematics, generalisation beyond the static limit in the kinematics, and inclusion of the ΔN Π energy-dependent vertex form factor. The new decay width provides a reasonable cut-off at high pion momenta and gives the correct momentum dependence in the limit of single-particle decay at low momenta. The results of calculations for the energy-dependent widths and their effects on the energy distributions of exclusive coherent pion production for 12 C+ 12 C → 12 C+ 12 C* (T = 1)+ Π 0 at incident energies below and above the pion threshold are shown and discussed. The new energy dependence is compared to the free Δ width used previously and it is seen that the new results give a smoother and more realistic shape to the pion energy distributions.

Partial inelasticity coefficients of negative pions in p, d, α, 12C+12C and p, 12C+181Ta collisions at 4.2 GeV/c per nucleon

2015 ◽  
Vol 24 (10) ◽  
pp. 1550070 ◽  
Author(s):  
Khusniddin K. Olimov ◽  
Kosim Olimov ◽  
K. G. Gulamov ◽  
Alisher K. Olimov ◽  
Sagdulla L. Lutpullaev ◽  
...  
Keyword(s):  
Charge Exchange ◽  
Incident Energy ◽  
Intermediate Energy ◽  
Experimental Results ◽  
Minimum Bias ◽  
Additional Source ◽  
Projectile Nucleus ◽  
High Energies ◽  
Intermediate Energies ◽  
A Charge

The partial inelasticity coefficients of the negative pions were determined in minimum bias p, d, α, 12 C +12 C and p, 12 C +18 Ta collisions at 4.2A GeV/c taking into account the average number of participant nucleons of a projectile nucleus. In nucleus–nucleus collisions, the average values of partial inelasticity coefficients (〈K(π-)〉) of the negative pions did not depend on the mass numbers of projectile and target nuclei. Increase of 〈K(π-)〉 in going from p+12 C to d, α, 12 C +12 C collisions was due to an additional source of production of fast negative pions in nucleus–nucleus collisions — a charge exchange conversion of one or more neutrons of a projectile nucleus into a proton and π-. Linking the experimental results of the present analysis at intermediate energy with those obtained at high and ultra-high energies, it was concluded that the average values of partial inelasticity coefficients of pions in nucleon–nucleus and nucleus–nucleus collisions manifest a transitive behavior. At intermediate energies, the values of 〈K(π-)〉 were smaller by a factor of two and more as compared to those at high energies, and they increased further with increasing incident energy, reaching a plateau at E0 > 100A GeV.

The interaction of atomic particles with solid surfaces at intermediate energies II. Scattering processes

1969 ◽  
Vol 314 (1516) ◽  
pp. 53-72 ◽  
Keyword(s):  
Incident Energy ◽  
Incident Particle ◽  
Solid Surfaces ◽  
Hydrogen Ions ◽  
Energy Distributions ◽  
Intermediate Energies ◽  
Positive Ions ◽  
Hydrogen Deuterium ◽  
Bombarding Energy ◽  
Positively Charged

Measurements were made of the energy distributions of charged particles emitted from targets of platinum, nickel and molybdenum bombarded by atomic and molecular positive ions of hydrogen, deuterium , helium , carbon, nitrogen, oxygen, neon, argon and carbondioxide, with energy 2 to 40 keV. It is shown that the scattering of incident particles is predominantly elastic and approximately independent of the charge state of the incident particle. Hydrogen, deuterium, carbon and oxygen are scattered with both positive and negative charges, but CO 2 gives only negatively charged scattered particles. Scattering with positive charge increases over an energy range 2 to 15 keV per incident particle, while scattering with negative charge increases to a maximum at incident energies 3 to 7 keV per particle and then decreases up to the highest energies used, 40 keV. Scattering with positive and negative charges is of the same magnitude at the incident energy corresponding with the maximum for negative scattering of hydrogen ions. The energy distribution of negatively charged scattered ions is generally broader than that for positively charged scattered ions at the same incident energy, for the lighter ions. Scattering as neutral atoms is estimated roughly and is shown to increase rapidly as the bombarding energy is reduced below about 10 keV.

Detection and Quantification of 7-Hydroxydehydroepiandrosterone Epimers in Three Body Fluids

2002 ◽  
Vol 67 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Richard Hampl ◽  
Martin Hill ◽  
Luboslav Stárka
Keyword(s):  
Healthy Subjects ◽  
Serum Levels ◽  
Body Fluids ◽  
Gas Chromatography Mass Spectrometry ◽  
Specific Radioimmunoassay ◽  
Order Of Magnitude ◽  
Three Body ◽  
First Time ◽  
Nanomolar Range ◽  
Detection And Quantification

3β,7α-Dihydroxyandrost-5-en-17-one (1) (7α-OH-DHEA) and its 7β-hydroxy epimer 2 (7β-OH-DHEA) - 7α- and 7β-hydroxydehydroepiandrosterone - were detected and quantified in three human body fluids: in blood serum, saliva and ejaculate. Specific radioimmunoassay and gas chromatography-mass spectrometry have been used. For the first time the data on changes of these dehydroepiandrosterone metabolites are reported for a representative group of healthy subjects of both sexes (172 females and 217 males) during the life span. The serum levels of both 7-hydroxydehydroepiandrosterone epimers in serum and also in semen were in the low nanomolar range, while concentrations by one order of magnitude lower were found in saliva, but still within the detection limit. The results will serve as a basis for comparative studies of 7-hydroxydehydroepiandrosterone levels under various pathophysiological conditions, with a particular respect to autoimmune disorders.

Charge exchange reactions on medium and heavy mass targets at intermediate energies

2019 ◽  
Vol 35 (08) ◽  
pp. 2050045
Author(s):  
Pardeep Singh ◽  
Monika Singh ◽  
Neha Rani
Keyword(s):  
Charge Exchange ◽  
Cross Sections ◽  
Energy Charge ◽  
Impulse Approximation ◽  
Mass Region ◽  
Intermediate Energy ◽  
Exchange Reactions ◽  
Plane Wave Impulse Approximation ◽  
Text Type ◽  
Intermediate Energies

The nuclear isotopic structure can be understood easily via the intermediate-energy charge exchange reactions of (p, n) and [Formula: see text]He, [Formula: see text] type. In the current contribution, we present some results for charge exchange reactions induced by 3He on targets lying in mass region [Formula: see text] within the theoretical framework of plane wave impulse approximation (PWIA) and distorted wave impulse approximation (DWIA). Here, the recoil effects in PWIA have also been considered. Particularly, the angular distributions and the unit cross-sections have been calculated and compared with the available data. Further, the importance of inclusion of the exchange contribution in these reactions is also considered, which eventually enhance the matching with data.

Determining the energy-dependent X-ray flux variation of a synchrotron beamline using Laue diffraction patterns

2011 ◽  
Vol 44 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Catherine Dejoie ◽  
Martin Kunz ◽  
Nobumichi Tamura ◽  
Colin Bousige ◽  
Kai Chen ◽  
...  
Keyword(s):  
Incident Energy ◽  
Flux Variation ◽  
Laue Diffraction ◽  
X Ray ◽  
Measured Flux ◽  
Highly Sensitive ◽  
Diffraction Patterns ◽  
Energy Dependent ◽  
Flux Curve

Although the spectrum originating from a superconducting bending magnet is quasi-continuous, it shows important intensity variations through its spectral range. A method to determine the incident energy-dependent flux variation based on the comparison between observed intensities and the calculated intensities of a well known structure (calcite) is presented here. It is found that the measured flux is highly sensitive to the use of correct Debye–Waller factors for the atoms of the standard crystal. By using the measured flux curve, it was possible to unambiguously index the Laue diffraction pattern of a trigonal crystal structure in its hexagonal setting. This is a crucial but difficult first step for the determination of strain and stress in materials with this symmetry, such as quartz, Mg, Ti, Znetc.

Three-body dynamics in the reactionH(e,2e)H + at intermediate energies

1989 ◽  
Vol 11 (3) ◽  
pp. 257-258 ◽  
Author(s):  
M. Brauner ◽  
J. S. Briggs ◽  
H. Klar
Keyword(s):  
Intermediate Energies ◽  
Body Dynamics ◽  
Three Body

scholarly journals CALCULATING TWO- AND THREE-BODY DECAYS WITH FeynArts AND FormCalc

2003 ◽  
Vol 14 (09) ◽  
pp. 1273-1278 ◽  
Author(s):  
MICHAEL KLASEN
Keyword(s):  
Standard Model ◽  
Particle Production ◽  
High Energy Physics ◽  
High Energy ◽  
Energy Distributions ◽  
Particle Decay ◽  
The Standard Model ◽  
Decay Widths ◽  
Three Body ◽  
Energy Physics

The Feynman diagram generator FeynArts and the computer algebra program FormCalc allow for an automatic computation of 2→2 and 2→3 scattering processes in High Energy Physics. We have extended this package by four new kinematical routines and adapted one existing routine in order to accomodate also two- and three-body decays of massive particles. This makes it possible to compute automatically two- and three-body particle decay widths and decay energy distributions as well as resonant particle production within the Standard Model and the Minimal Supersymmetric Standard Model at the tree- and loop-level. The use of the program is illustrated with three standard examples: [Formula: see text], [Formula: see text], and [Formula: see text].

scholarly journals Three-body fragmentation dynamics of OCS3+ induced by intermediate energy Ne4+ ion impact

2018 ◽  
Vol 67 (4) ◽  
pp. 043401
Author(s):  
Shen Li-Li ◽  
Yan Shun-Cheng ◽  
Ma Xin-Wen ◽  
Zhu Xiao-Long ◽  
Zhang Shao-Feng ◽  
...  
Keyword(s):  
Intermediate Energy ◽  
Fragmentation Dynamics ◽  
Ion Impact ◽  
Three Body
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