Partial-wave analysis of lepton-pair annihilation into two photons

1986 ◽  
Vol 64 (10) ◽  
pp. 1359-1364 ◽  
Author(s):  
Winston Roberts
Keyword(s):  
Partial Wave ◽  
Cross Section ◽  
Quantum Electrodynamics ◽  
Negative Parity ◽  
Partial Cross Section ◽  
Lepton Pair ◽  
Partial Wave Analysis ◽  
Final States ◽  
Lepton Pairs ◽  
Pair Annihilation

The partial-wave (Jp) composition of the process ℓ+ℓ− → γγ is analyzed in lowest order quantum electrodynamics. The results for low-momentum leptons are as expected, the partial wave with Jp = 0− being dominant. At high energies, the partial wave with Jp = 2+ has the largest single partial cross section. At all energies, it is found that lepton pairs in the triplet state give rise exclusively to positive-parity final states, whereas pairs in the singlet state give rise to negative-parity final states.Some features of the differential cross section are also explained in terms of the spin state of the annihilating lepton pair. Possible implications for e+e− → γγ → hadrons and [Formula: see text] hadrons are briefly discussed.

PARTIAL WAVE ANALYSIS AT LEAR

2003 ◽  
Vol 18 (03) ◽  
pp. 497-507
Author(s):  
Klaus Peters
Keyword(s):  
Partial Wave ◽  
Partial Wave Analysis ◽  
Initial System ◽  
Final States ◽  
Wave Analysis

Methods and special techniques for partial wave analysis and dalitzplot analysis in the framework of antiproton nucleon annihilation are presented. The properties of the initial system and the constraints on the final states are discussed as well as many details about the setup and strategy of the analyses. This information was compiled mainly from the experiments Crystal Barrel, Obelix and Asterix but is certainly not complete in many respects.

An isobar model partial-wave analysis of three-body final states in π+p interactions from threshold to 1700 MeV c.m. energy

1980 ◽  
Vol 168 (2) ◽  
pp. 243-271 ◽  
Author(s):  
K.W.J. Barnham ◽  
S.L. Glickman ◽  
W.A.C. Mier-Jedrzejowicz ◽  
S.J. Orebi Gann ◽  
R.A. Stevens ◽  
...  
Keyword(s):  
Partial Wave ◽  
Partial Wave Analysis ◽  
Final States ◽  
Wave Analysis ◽  
Isobar Model ◽  
Three Body

Partial-wave analysis and multipole transition interferences in the breakup of 6Li on 152Sm target

2017 ◽  
Vol 26 (11) ◽  
pp. 1750075
Author(s):  
B. Mukeru ◽  
M. L. Lekala
Keyword(s):  
Partial Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Breakup Reaction ◽  
Partial Wave Analysis ◽  
Breakup Cross Section ◽  
Interference Effects ◽  
Breakup Process ◽  
Wave Analysis ◽  
Resonant States

We have performed a detailed partial-wave analysis in order to analyze each partial-wave contribution to the breakup cross-sections as well as multipole interference effects in the [Formula: see text] breakup reaction. The results show that [Formula: see text]-waves contribute up to 67.03% of the overall integrated total breakup cross-section, distributed as follows: 10.43% for the [Formula: see text] partial-wave, 21.94% for the [Formula: see text] partial-wave and 34.66% for the [Formula: see text] partial-wave. A similar trend is observed for both Coulomb and nuclear breakup cross-sections. The importance of [Formula: see text]-waves over the non-[Formula: see text]-waves in the breakup process is mainly due to the higher-order multipole interferences. It is also obtained that the combination of [Formula: see text]-waves and [Formula: see text]-waves accounts for 84.77%, 89.95% and 73.58% of the total, Coulomb and nuclear breakup cross-sections, respectively. Considering the results obtained for the [Formula: see text] and [Formula: see text] partial-waves, we conclude that the [Formula: see text] and [Formula: see text] resonant breakup cross-sections, which can be obtained by integrating over the resonant energy range, could not be negligible compare to the [Formula: see text] resonant breakup cross-section. As far as this reaction is concerned, we can conclude that in the sequential breakup of [Formula: see text], excitations to all its three resonant states should be considered for a fair description of such process.

scholarly journals On the Bhabha scattering for z = 2 Lifshitz QED

2015 ◽  
Vol 30 (16) ◽  
pp. 1550086 ◽  
Author(s):  
R. Bufalo
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Quantum Electrodynamics ◽  
Free Parameter ◽  
Classical Solutions ◽  
Photon Exchange ◽  
Small Deviations ◽  
Bhabha Scattering ◽  
Pair Annihilation ◽  
Fermionic Fields

In this paper, we compute and discuss the differential cross-section of the Bhabha scattering in the framework of the z = 2 Lifshitz quantum electrodynamics (QED). We start by constructing the classical solutions for the fermionic fields, in particular the completeness relations, and also derive the theory's propagators. Afterwards, we compute the photon exchange and pair annihilation contributions for the Bhabha's process, and upon achieving the results we establish the magnitude of the theory's free parameter by looking for small deviations of the QED tree results.

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