scholarly journals Determining dominant partial waves in photoproduction via moment analysis

2020 ◽  
Vol 241 ◽  
pp. 03006
Author(s):  
Yannick Wunderlich

Important insights into the excitation spectra of baryons are provided by measurements of polarization observables in reactions that involve particles with spin. The photoproduction of a single pseudoscalar meson constitutes an example-reaction that has been under intense investigation recently. We present the basic method of moment-analysis for pseudoscalar meson photoproduction, in which just the angular distributions are analyzed. Using this method, the total angular momentum quantum number of the dominant partial waves contributing in the data can be extracted quickly. Furthermore, the Legendre-coeffcients extracted from the angular distributions show interesting composition-patterns in terms of multipoles and allow for instructive comparisons to models. In this contribution, recent results for moment analyses of polarization data for the photoproduction of pions and eta-mesons are shown.

2020 ◽  
Vol 241 ◽  
pp. 01007
Author(s):  
Takatsugu Ishikawa ◽  
Hisako Fujimura ◽  
Hiroshi Fukasawa ◽  
Ryo Hashimoto ◽  
Qinghua He ◽  
...  

The B = 2 bound/resonance state (dibaryon) is an interesting object, which can be a molecule consisting of two baryons or a spatially compact hexaquark hadron object. The yd ^ n°n°d reaction has been experimentally investigated at incident energies ranging from 0.58 to 1.15 GeV to study non-strange dibaryons. The angular distributions of deuteron emission in the yd center-of-mass energy cannot be reproduced by quasi-free production of two neutral pions followed by deuteron coalescence. Additionally a 2.14-GeV peak is observed in the n°d invariant mass distribution. These suggest a sequential process such as yd ^ RIS ^ n°RIV ^ n°n°d with an isoscalar dibaryon RIS and an isovector dibaryon RIV. Since the mass of the observed isoscalar dibaryons are close to the sum of the nucleon (N) and nucleon resonance (N*) masses, an S-wave NN* molecule may play a role as a doorway to a dibaryon.


1979 ◽  
Vol 20 (7) ◽  
pp. 1553-1583 ◽  
Author(s):  
D. J. Quinn ◽  
J. P. Rutherford ◽  
M. A. Shupe ◽  
D. J. Sherden ◽  
R. H. Siemann ◽  
...  

2015 ◽  
Vol 267-269 ◽  
pp. 230-232 ◽  
Author(s):  
J.J. Quirós ◽  
D.F. Tamayo ◽  
D.E. Jaramillo ◽  
C. Barbero

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