Interpretation of measurements of ?0-meson photoproduction partial cross sections on a6Li nucleus with O+ level excitation

1991 ◽  
Vol 34 (11) ◽  
pp. 1025-1029 ◽  
Author(s):  
V. A. Tryasuchev ◽  
A. I. Fiks
Keyword(s):  
Cross Sections ◽  
Meson Photoproduction

scholarly journals RESTRICTED LOCALITY OF QUARK-HADRON DUALITY IN EXCLUSIVE MESON PHOTOPRODUCTION REACTIONS ABOVE THE RESONANCE REGION

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1910-1913 ◽  
Author(s):  
QIANG ZHAO ◽  
FRANK E. CLOSE
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Scaling Laws ◽  
Resonance Region ◽  
Meson Photoproduction ◽  
Counting Rule ◽  
Dimensional Scaling ◽  
Exclusive Processes ◽  
Photoproduction Reactions ◽  
Hadron Duality

We show how deviations from the dimensional scaling laws for exclusive processes may be related to a breakdown in the locality of quark-hadron duality, i.e. the "restricted locality". For exclusive reactions like meson photo- and electroproduction above the resonance region, we explore the effects arising from such a local duality breaking and propose that it can be a possible source for oscillations about the smooth quark counting rule predicted by pQCD in the 90-degree differential cross sections.

RHO meson photoproduction cross-sections in the strong absorption model

1966 ◽  
Vol 22 (2) ◽  
pp. 217-219 ◽  
Author(s):  
Y. Eisenberg ◽  
E.E. Ronat ◽  
A. Brandstetter ◽  
A. Levy ◽  
E. Gotsman
Keyword(s):  
Cross Sections ◽  
Strong Absorption ◽  
Absorption Model ◽  
Meson Photoproduction ◽  
Rho Meson

scholarly journals Near threshold heavy vector meson photoproduction at LHC and EicC

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Ya-Ping Xie ◽  
V. P. Gonçalves
Keyword(s):  
Vector Meson ◽  
Cross Sections ◽  
Meson Production ◽  
Meson Photoproduction ◽  
Fixed Target ◽  
Vector Meson Production ◽  
Total Cross Sections ◽  
Low Energies ◽  
Lhcb Detector ◽  
Near Threshold

AbstractThe exclusive $$J/\Psi $$ J / Ψ and $$\Upsilon $$ Υ photoproduction in fixed - target collisions at the LHC and ep(A) collisions at the Electron ion collider in China (EicC) is investigated considering different models for the treatment of the vector meson production at low energies, close to the threshold. Results for the total cross sections and associated distributions are presented. We predict a large number of $$J/\Psi $$ J / Ψ events at the LHC in the rapidity range covered by the LHCb detector. For the EicC, our predictions point out that a detailed analysis of the near threshold $$J/\Psi $$ J / Ψ and $$\Upsilon $$ Υ photoproduction is feasible. Moreover, our results indicate that the modeling of the near threshold vector meson production can be constrained by future experimental analyzes at the LHC and EicC.

Measurements of Elasticρ- andϕ-Meson Photoproduction Cross Sections on Protons from 30 to 180 GeV

1979 ◽  
Vol 43 (10) ◽  
pp. 657-660 ◽  
Author(s):  
R. M. Egloff ◽  
P. J. Davis ◽  
G. J. Luste ◽  
J. F. Martin ◽  
J. D. Prentice ◽  
...  
Keyword(s):  
Cross Sections ◽  
Meson Photoproduction

Measurements of Diffractive Vector-Meson Photoproduction at High Momentum Transfer from the ZEUS Experiment at HERA

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 187-189
Author(s):  
James A. Crittendenr
Keyword(s):  
Momentum Transfer ◽  
Cross Sections ◽  
Zeus Collaboration ◽  
Center Of Mass ◽  
High Momentum ◽  
Mass Energy ◽  
Meson Photoproduction ◽  
High Momentum Transfer ◽  
Center Of Mass Energy ◽  
Dissociated State

We discuss recent preliminary results on the diffractive photoproduction of ρ0, ϕ, and J/ψ mesons at high momentum transfer reported by the ZEUS collaboration at HERA. A special-purpose calorimeter served to tag the quasi-real photons (Q2<0.01 GeV 2) in the process γ+p→ VM +Y, where Y represents a dissociated state of the proton. The resulting range in photon-proton center-of-mass energy extends from 80 to 120 GeV. The differential cross sections [Formula: see text] were obtained in the region |t| > 1.2 GeV 2, where t denotes the squared momentum transfer to the proton. The measurements provide good sensitivity to the observed power-law dependence [Formula: see text]. Over the region in momentum transfer covered by the data, the power is found to be approximately n ≃ 3 for ρ0 and ϕ photoproduction, and approximately n ≃ 2 for J/ψ photoproduction.

scholarly journals Double polarisation observable E and helicity dependent cross section for single π0 photoproduction off proton and neutron

2020 ◽  
Vol 241 ◽  
pp. 01005
Author(s):  
Susanna Costanza ◽  
Federico Cividini
Keyword(s):  
Cross Sections ◽  
Pion Production ◽  
Photon Beam ◽  
Reaction Products ◽  
Meson Photoproduction ◽  
Production Threshold ◽  
Resonance Properties ◽  
Large Acceptance ◽  
Polarised Beams

Photon-induced reactions, like meson photoproduction, allow to excite the nucleon, to have access to many different polarisation observables and are an essential tool to disentangle the role of the different electromagnetic multipoles due to the change of sign of some contributions and the presence of interference terms between different multipole amplitudes. In addition, the use of polarised beams and/or targets allow to access additional observables which are fundamental in order to accurately determine the nucleon resonance properties. The A2@MAMI collaboration is carrying out a broad and systematic study on this topics, both on the proton and the neutron. The experiments are performed at the tagged photon beam facility of the MAMI accelerator in Mainz, using circularly and linearly polarised photons on longitudinally polarised proton and deuteron targets, for energies ranging from the pion production threshold up to 1.6 GeV. Hadronic reaction products are then measured with the large acceptance Crystal Ball spectrometer, complemented by charged particle and vertex detectors for tracking and identification. An overview of the results obtained so far for the double polarisation observable E (circularly polarised photon beam on a longitudinally polarised target) on the single π0 photoproduction off the proton and the neutron will be given. Furthermore, new results on the helicity-dependent total and differential cross sections on the deuteron will be presented.

THE ETA-MESON PHOTOPRODUCTION ON PROTON

2011 ◽  
Vol 26 (03n04) ◽  
pp. 645-646
Author(s):  
JAN DONOVAL ◽  
PETR BYDŽOVSKÝ
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Cross Sections ◽  
Form Factors ◽  
Coupling Constants ◽  
Tree Level ◽  
Recent Experimental Data ◽  
Model Coupling ◽  
Eta Meson ◽  
Meson Photoproduction

We have performed the tree-level calculations of the eta meson photoproduction on proton for photon laboratory energies between 714 and 1500 MeV. The resonances N (1535), N (1710), N (1650), N (1440) and N (1520) were assumed. The form factors were introduced in the hadron vertices to involve the structure of hadrons. The influence of various form factor recipes was investigated. In order to keep gauge invariance, the appropriate contact term was introduced. The parameters of our model (coupling constants, cutoffs) were fitted to recent experimental data of the cross sections and some polarization observables.

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