Angular distributions, relative orbital angular momenta, and spins of fragments originating from the binary fission of polarized nuclei

2003 ◽  
Vol 66 (7) ◽  
pp. 1219-1228 ◽  
Author(s):  
S. G. Kadmensky ◽  
L. V. Rodionova
Keyword(s):  
Binary Fission ◽  
Angular Distributions ◽  
Angular Momenta

A quasi-classical trajectory (QCT) study of the H + OF reaction stereodynamics

2010 ◽  
Vol 88 (9) ◽  
pp. 893-897 ◽  
Author(s):  
Dan Zhao ◽  
Tian Yu Zhang ◽  
Tian Shu Chu
Keyword(s):  
Cross Sections ◽  
Relative Velocity ◽  
Collision Energy ◽  
Potential Surface ◽  
Excited Electronic State ◽  
Three Dimensional ◽  
Chem Phys ◽  
Classical Trajectory ◽  
Angular Distributions ◽  
Angular Momenta

Based on the global three-dimensional adiabatic potential surface of the 13A′ excited electronic state (J. Chem. Phys. 2005, 123, 114310) of the OHF system, we investigated the H + OF → OH + F/HF + O reaction stereodynamics by using the quasi-classical trajectory (QCT) method. The four polarization-dependent differential cross sections (PDDCSs) and the three angular distributions P(θr), P([Formula: see text]), P(θr, [Formula: see text]) were calculated at a low collision energy of 0.48 eV for both product channels. The results indicated that the products are backward-scattering on the triplet state, and the product rotational angular momenta are aligned or oriented. Moreover, there is a remarkable difference between the polarization behaviors of the two product channels. Product orientation exhibited by the OH + F channel is found to be absent in the HF + O channel at this collision energy albeit the latter shows stronger alignment along the direction perpendicular to the reagent relative velocity k than OH + F.

Study of the 48Ti(α,p)51V and 50Ti(3He,d)51V Reactions

1971 ◽  
Vol 49 (8) ◽  
pp. 1053-1065 ◽  
Author(s):  
P. N. Maheshwari ◽  
U. C. Gupta ◽  
C. St-Pierre
Keyword(s):  
Optical Model ◽  
Energy Levels ◽  
Angular Distributions ◽  
Model Parameters ◽  
Model Calculations ◽  
Angular Momenta ◽  
Rotator Model ◽  
Spectroscopic Factors ◽  
New Energy ◽  
Bombarding Energy

The reactions 48Ti(α,p)51V at ten bombarding energies between 8.25 and 10.75 MeV and 50Ti(3He,d)51V at 10 MeV bombarding energy have been studied. Energy levels of 51V up to 4.85 and 6.17 MeV have been observed by (α,p) and (3He,d) reactions respectively. The (α,p) reaction yielded many new energy levels. The angular distributions for deuterons were measured at lab angles between 15° and 120°, and compared with predictions of DWBA calculations using the TSALLY code from which the transferred angular momenta and spectroscopic factors were deduced. These experimental results are examined from the viewpoint of shell model and strong coupling rotator model calculations. The effect of changing various optical model parameters is also discussed.

scholarly journals A Note on Resonance Angular Distributions with Application to Nucleon?Antinucleon Scattering and Annihilation

1973 ◽  
Vol 26 (4) ◽  
pp. 441
Author(s):  
DC Peaslee ◽  
DM Rosalky
Keyword(s):  
Angular Distributions ◽  
Unnatural Parity ◽  
Angular Momenta ◽  
Pseudoscalar Mesons ◽  
Natural Parity ◽  
Resonance Spin

Angular distributions have been calculated for the reactions NN -+ NN and NN -+ 2 pseudoscalar mesons by assuming the formation of an intermediate isolated state. The scattering distributions are only found to have the characteristic oscillatory shape for unnatural parity resonances whereas those for natural parity states are smooth. The annihilation distributions display an exact degeneracy with respect to the interchange of orbital and total angular momenta. For both reactions, the width of the forward and backward peak is approximately inversely proportional to the resonance spin.

Angular distributions from ( d, p ) and ( d, n ) nuclear reactions

1951 ◽  
Vol 208 (1095) ◽  
pp. 559-579 ◽  
Keyword(s):  
Excited States ◽  
Ground State ◽  
Nuclear Reactions ◽  
Energy Levels ◽  
Angular Distributions ◽  
Angular Momenta ◽  
First Excited State ◽  
Compound Nucleus Formation ◽  
Initial Nucleus

Experimental angular distributions from (d, p) and (d, n) nuclear reactions involve con­tributions from incident angular momenta much higher than is compatible with compound nucleus formation, and indicate that these reactions must proceed to a large extent by means of a stripping process. The angular distributions to be expected from a stripping process are calculated, and these are found to be very sensitive to the angular momenta which can be accepted by the initial nucleus, i.e. to the spins and parities of the energy levels involved. In any one case there is found excellent agreement between the experimental curve and just one of the possible theoretical curves, and if the spin and parity of the ground state of the initial nucleus is known, this allows of a determination of the spin and parity of the appropriate level of the final nucleus. In this way it is found, for example, that the ground state of 17 O has spin ⅝ or ⅜ and even parity, and that the first excited state of 17 O (0.88 MeV above ground) has spin ½ and even parity. Determinations are also made of the spins and parities of the ground states and several excited states of 13 C, 15 N and 28 Al. Families of theoretical curves for a variety of incident and outgoing energies are presented in order to facilitate further spin and parity determinations from future experimental results.

scholarly journals Elastic scattering of slow electrons by carbon nanotubes

2021 ◽  
Author(s):  
Miron Ya. Amusia ◽  
Arkadiy S Baltenkov
Keyword(s):  
Carbon Nanotubes ◽  
Elastic Scattering ◽  
Cross Sections ◽  
Angular Distributions ◽  
Slow Electron ◽  
Scattering Cross ◽  
Angular Momenta ◽  
Incoming Electron ◽  
Slow Electrons ◽  
Scattering Cross Sections

Abstract In this paper we calculate the elastic scattering cross sections of slow electron by carbon nanotubes. The corresponding electron-nanotube interaction is substituted by a zero-thickness cylindrical potential that neglects the atomic structure of real nanotubes, thus limiting the range of applicability of our approach to sufficiently low incoming electron energies. The strength of the potential is chosen the same that was used in describing scattering of electrons by fullerene C60. We present results for total and partial electron scattering cross sections as well as respective angular distributions, all with account of five lowest angular momenta contributions. In the calculations we assumed that the incoming electron moves perpendicular to the nanotube axis, since along the axis the incoming electron moves freely.

scholarly journals Time-reversal asymmetries and angular distributions in Λb → ΛV

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Chao-Qiang Geng ◽  
Chia-Wei Liu
Keyword(s):  
Time Reversal ◽  
Branching Ratio ◽  
New Physics ◽  
Angular Distributions ◽  
Factorization Approach ◽  
Spin Correlations ◽  
Angular Momenta ◽  
Pseudoscalar Mesons ◽  
Helicity Amplitudes ◽  
Cp Asymmetries

Abstract We study the spin correlations to probe time-reversal (T) asymmetries in the decays of Λb→ ΛV (V = ϕ, ρ0, ω, K∗0). The eigenstates of the T-odd operators are obtained along with definite angular momenta. We obtain the T-odd spin correlations from the complex phases among the helicity amplitudes. We give the angular distributions of Λb→ Λ(→ pπ−)V (→ PP′) and show the corresponding spin correlations, where P(′) are the pseudoscalar mesons. Due to the helicity conservation of the s quark in Λ, we deduce that the polarization asymmetries of Λ are close to −1. Since the decay of Λb→ Λϕ in the standard model (SM) is dictated by the single weak phase from the product of CKM elements, $$ {V}_{tb}{V}_{ts}^{\ast } $$ V tb V ts ∗ , the true T and CP asymmetries are suppressed, providing a clean background to test the SM and search for new physics. In the factorization approach, as the helicity amplitudes in the SM share the same complex phase, T-violating effects are absent. Nonetheless, the experimental branching ratio of Br(Λb→ Λϕ) = (5.18 ± 1.29) × 10−6 suggests that the nonfactorizable effects or some new physics play an important role. By parametrizing the nonfactorizable contributions with the effective color number, we calculate the branching ratios and direct CP asymmetries. We also explore the possible T-violating effects from new physics.

The Ultrastructure of the Nuclear Events of Binary Fission in Paramecium bursaria and the Effects of Colchicine on Cell Division

1974 ◽  
Vol 32 ◽  
pp. 276-277
Author(s):  
L. M. Lewis
Keyword(s):  
Cell Division ◽  
Nuclear Envelope ◽  
Condensed Chromatin ◽  
Binary Fission ◽  
Paramecium Bursaria ◽  
Nuclear Events ◽  
Division Axis

The effects of colchicine on extranuclear microtubules associated with the macronucleus of Paramecium bursaria were studied to determine the possible role that these microtubules play in controlling the shape of the macronucleus. In the course of this study, the ultrastructure of the nuclear events of binary fission in control cells was also studied.During interphase in control cells, the micronucleus contains randomly distributed clumps of condensed chromatin and microtubular fragments. Throughout mitosis the nuclear envelope remains intact. During micronuclear prophase, cup-shaped microfilamentous structures appear that are filled with condensing chromatin. Microtubules are also present and are parallel to the division axis.

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