scholarly journals Decay Angular Distribution of a Vector-Meson Produced by Polarized Leptons in the Quark Model

1974 ◽  
Vol 52 (1) ◽  
pp. 259-266 ◽  
Author(s):  
M. Hayashi ◽  
K. Kstsuura
2003 ◽  
Vol 18 (02n06) ◽  
pp. 370-373 ◽  
Author(s):  
Y. YAN ◽  
C. KOBDAJ ◽  
W. UCHAI ◽  
AMAND FAESSLER ◽  
T. GUTSCHE ◽  
...  

The reactions of electron-position annihilation into nucleon-antinucleon pairs have been studied in a nonperturbative quark model. The work suggests that the two-step process, in which the primary [Formula: see text] pair forms first a meson and then the meson decays into baryon pair, is dominant over the one-step process in which the primary [Formula: see text] pair is directly dressed by two additional [Formula: see text] pairs to form a baryon pair. The experimental data indicates that there exists a vector meson with quantum numbers IG(JPC) = 0-(1--) and a mass around 2 GeV.


1974 ◽  
Vol 73 (2) ◽  
pp. 202-218 ◽  
Author(s):  
B. Hyams ◽  
C. Jones ◽  
P. Weilhammer ◽  
W. Blum ◽  
H. Dietl ◽  
...  

2011 ◽  
Vol 26 (15) ◽  
pp. 2523-2535 ◽  
Author(s):  
XIAN-WEI KANG ◽  
HAI-BO LI ◽  
GONG-RU LU ◽  
ALAKABHA DATTA

In this paper, we study CP violation in [Formula: see text] and [Formula: see text] decays, where B, P and V denote a light spin-½ baryon, pseudoscalar and a vector meson respectively. In these processes the T odd CP violating triple-product (TP) correlations are examined. The genuine CP violating observables which are composed of the helicity amplitudes occurring in the angular distribution are constructed. Experimentally, by performing a full angular analysis it is shown how one may extract the helicity amplitudes and then obtain the TP asymmetries. We estimate the TP asymmetries in [Formula: see text] decays to be negligible in the Standard Model making these processes an excellent place to look for new physics. Taking a two-Higgs doublet model, as an example of new physics, we show that large TP asymmetries are possible in these decays. Finally, we discuss how BES-III and super τ-charm experiments will be sensitive to these CP violating signals in [Formula: see text] decays.


2019 ◽  
Vol 204 ◽  
pp. 08006 ◽  
Author(s):  
Viktor Andreev ◽  
Vadzim Haurysh

The procedure for obtaining the radiative decay constants of pseudoscalar and vector unflavored mesons in point–form of Poincaré-invariant quantum mechanics is presented. In the course of the work the authors determine the remaining parameters from V → Pγ and P → Vγ experimental decay value, using the obtained earlier parameters of the model for light (u, d and s) quarks. As a result, the mixing angles for pseudoscalar and vector meson sector were obtained taking into account gluonium content for η – η′ meson sector.


1957 ◽  
Vol 35 (9) ◽  
pp. 1042-1056 ◽  
Author(s):  
D. A. Bromley ◽  
H. E. Gove ◽  
A. E. Litherland ◽  
E. Almqvist ◽  
E. B. Paul

Information on the low levels in Si29 has been obtained by studying the gamma radiation associated with the Si29(p, p′γ)Si29 inelastic-scattering reaction in the proton-energy range from 2.5 to 3.0 Mev. and with the Al29(β−)Si29 negatron decay. Angular-distribution measurements have shown that the 2.03 Mev. level in Si29 has spin 5/2, and are consistent with a 3/2 assignment to the 1.28 Mev. level. The E2/M1E2 branching ratio for the de-excitation of the 2.03 Mev. state has been measured to be approximately 100. Log ft values of < 5.2, > 6.5, and 5.2 have been determined for the branches of the Al29 decay to the 2.43, 2.03, and 1.28 Mev. states in Si29.


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