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

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

Diffractive hadron production at ultrahigh energies

2015 ◽  
Vol 30 (11) ◽  
pp. 1550054 ◽  
Author(s):  
V. V. Anisovich ◽  
M. A. Matveev ◽  
V. A. Nikonov
Keyword(s):  
Energy Region ◽  
Hadron Production ◽  
Ultrahigh Energy ◽  
Production Amplitude ◽  
Initial State ◽  
Final State ◽  
Black Disk ◽  
Diffractive Production ◽  
Three Body ◽  
K Matrix

Diffractive production is considered in the ultrahigh energy region where pomeron exchange amplitudes are transformed into black disk ones due to rescattering corrections. The corresponding corrections in hadron reactions h1 + h3 → h1 + h2 + h3 with small momenta transferred [Formula: see text] are calculated in terms of the K-matrix technique modified for ultrahigh energies. Small values of the momenta transferred are crucial for introducing equations for amplitudes. The three-body equation for hadron diffractive production reaction h1 + h3 → h1 + h2 + h3 is written and solved precisely in the eikonal approach. In the black disk regime final state scattering processes do not change the shapes of amplitudes principally but dump amplitudes by a factor ~ ¼; initial state rescatterings result in additional factor ~ ½. In the resonant disk regime initial and final state scatterings damp strongly the production amplitude that corresponds to σ inel /σ tot → 0 at [Formula: see text] in this mode.

Hadron diffractive production at ultrahigh energies and shadow effects

2016 ◽  
Vol 31 (28n29) ◽  
pp. 1645019 ◽  
Author(s):  
V. V. Anisovich ◽  
M. A. Matveev ◽  
V. A. Nikonov
Keyword(s):  
Light Nuclei ◽  
Ultrahigh Energy ◽  
Initial State ◽  
Final State ◽  
Black Disk ◽  
Deuteron Scattering ◽  
High Energies ◽  
Hadron Level ◽  
Diffractive Production ◽  
Three Body

Shadow effects at collisions of hadrons with light nuclei at high energies were subject of scientific interest of V.N. Gribov, first, we mean his study of the hadron-deuteron scattering, see Sov. Phys. JETP 29, 483 (1969) [Zh. Eksp. Teor. Fiz. 56, 892 (1969)] and discovery of the reinforcement of shadowing due to inelastic diffractive rescatterings. It turns out that the similar effect exists on hadron level though at ultrahigh energies. Diffractive production is considered in the ultrahigh energy region where pomeron exchange amplitudes are transformed into black disk ones due to rescattering corrections. The corresponding corrections in hadron reactions [Formula: see text] with small momenta transferred ([Formula: see text], [Formula: see text]) are calculated in terms of the [Formula: see text]-matrix technique modified for ultrahigh energies. Small values of the momenta transferred are crucial for introducing equations for amplitudes. The three-body equation for hadron diffractive production reaction [Formula: see text] is written and solved precisely in the eikonal approach. In the black disk regime final state scattering processes do not change the shapes of amplitudes principally but dump amplitudes by a factor [Formula: see text]; initial state rescatterings result in additional factor [Formula: see text]. In the resonant disk regime initial and final state scatterings damp strongly the production amplitude that corresponds to [Formula: see text] at [Formula: see text] in this mode.

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.

scholarly journals Dual subtractions

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Renato Maria Prisco ◽  
Francesco Tramontano
Keyword(s):  
Field Theory ◽  
Quantum Field ◽  
Matrix Elements ◽  
Leading Order ◽  
Initial State ◽  
Final State ◽  
Dual Representation ◽  
Subtraction Scheme ◽  
Theoretical Predictions ◽  
Perturbative Quantum

Abstract We propose a novel local subtraction scheme for the computation of Next-to-Leading Order contributions to theoretical predictions for scattering processes in perturbative Quantum Field Theory. With respect to well known schemes proposed since many years that build upon the analysis of the real radiation matrix elements, our construction starts from the loop diagrams and exploits their dual representation. Our scheme implements exact phase space factorization, handles final state as well as initial state singularities and is suitable for both massless and massive particles.

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.

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

CHARMFUL BARYONIC $B\, \to \,{\rm{B\bar B}}'M_{c}$ DECAYS

2009 ◽  
Vol 24 (18n19) ◽  
pp. 3638-3644 ◽  
Author(s):  
YU-KUO HSIAO
Keyword(s):  
Branching Fraction ◽  
B Decays ◽  
Final State ◽  
Three Body

We study the charmful three-body baryonic B decays with D(*) or J/Ψ in the final state. We explain the measured rates of [Formula: see text], [Formula: see text], and [Formula: see text]. In particular, the branching fraction of [Formula: see text] predicted to be of order 2.3 × 10-6 is in accordance with the Belle measurement, [Formula: see text].

The Activities of the Tube Feet of Asterias Rubens L

1947 ◽  
Vol s3-88 (1) ◽  
pp. 1-14
Author(s):  
J. E. SMITH
Keyword(s):  
Forward Direction ◽  
The Other ◽  
Asterias Rubens ◽  
Ideal Form ◽  
First Time ◽  
Intrinsic Musculature ◽  
Tube Feet ◽  
Postural Muscles ◽  
The Ideal

1. An account is given of the muscular anatomy of the foot and ampulla of Asterias rubens. An intrinsic musculature of the sucker figured by Cuénot (1891) and Chadwick (1923) is shown not to be present; on the other hand, postural muscles responsible for orientating the podium, levator fibres which ‘cup’ the sucker, and radial fibres which flatten it are described and figured for the first time. 2. The role of the different muscle systems, the collagen connective tissue, and the fluid of the hydrocoel in protracting and retracting the foot, and in effecting the attachment and detachment of the sucker, is discussed. 3. Evidence is presented, to show that postural pointing of the foot is brought about by the contraction of a ring of muscles encircling the base of the podium. The orienting muscles are functionally, but not anatomically, distinct from the longitudinal fibres of the retractor sheath. 4. The ambulatory step is shown to comprise a series of linked phases of static posture and of movement. Each phase is characterized by the contraction of one member of each of the two opposing pairs of muscles engaged in the development of the step. The two pairs of muscles are (1) the anterior and posterior orienting fibres, and (2) the protractors and retractors of the foot. In its ideal form the step comprises four phases of static posture alternating with four movements. Each movement is ushered in by a reversal of the contraction-relaxation relationships of one of the two pairs of opposing muscle systems. Four such changes are possible and they occur in a sequence that ensures the orderly succession of the four movements of protraction, swing back, retraction, and swing forward, of which movements the idealized stepping cycle is composed. 5. The actual locomotory step departs from the ideal form in two respects: (1) it is liable to become disrupted by a delay in the initiation of the protraction or of the backswing movement, and (2) withdrawal of the podium occurs simultaneously with its re-orientation in the forward direction. It is pointed out that these variations are explicable on the assumption that, in the two series of opposing muscle pairs, the retractor fibres are more readily excited to contract than are their antagonists, and the anterior postural muscles than the posterior postural fibres.

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