scholarly journals J/ψ -meson production within improved color evaporation model with the kT -factorization approach for cc¯ production

2019 ◽  
Vol 99 (5) ◽  
Author(s):  
Rafał Maciuła ◽  
Antoni Szczurek ◽  
Anna Cisek
Keyword(s):  
Meson Production ◽  
Factorization Approach ◽  
Evaporation Model

scholarly journals NUCLEAR SHADOWING EFFECTS ON CHARMONIUM PRODUCTION IN QCD

1998 ◽  
Vol 13 (06) ◽  
pp. 453-463 ◽  
Author(s):  
C. PAJARES ◽  
C. A. SALGADO ◽  
Yu. M. SHABELSKI
Keyword(s):  
Experimental Data ◽  
Structure Functions ◽  
Nuclear Medium ◽  
Color Singlet ◽  
Separate Study ◽  
Factorization Approach ◽  
Parton Distributions ◽  
Charmonium Production ◽  
Evaporation Model ◽  
Nonrelativistic Qcd

It is shown that the effects on charmonium production of the modification of nucleon parton distributions inside nuclei are similar in the factorization approach based on nonrelativistic QCD and in the color evaporation model. In the first model, a separate study of the color octet and color singlet contributions to the yields of the various charmonium states as well as the contributions of these states to the total J/ψ production is performed. It is found that a clear xF dependence of these contributions which, together with an overall normalization given by absorption of the pre-resonant [Formula: see text] state inside the nuclear medium, can reproduce experimental data a for moderate xF. However, at large xF, there is bigger suppression that cannot be fit by this overall normalization together with the shadowing of structure functions.

scholarly journals Bottomonium production and polarization in the NRQCD with $$k_T$$-factorization. III: $$\Upsilon (1S)$$ and $$\chi _b(1P)$$ mesons

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
N. A. Abdulov ◽  
A. V. Lipatov
Keyword(s):  
Bound States ◽  
Meson Production ◽  
Spin Density Matrix ◽  
Factorization Approach ◽  
Direct Production ◽  
Transverse Momentum Dependent ◽  
Radiation Theory ◽  
Multipole Radiation ◽  
Shell Production ◽  
Upsilon 1S

AbstractThe $$\Upsilon (1S)$$ Υ ( 1 S ) meson production and polarization at high energies is studied in the framework of the $$k_T$$ k T -factorization approach. Our consideration is based on the non-relativistic QCD formalism for a bound states formation and off-shell production amplitudes for hard partonic subprocesses. The direct production mechanism, feed-down contributions from radiative $$\chi _b(mP)$$ χ b ( m P ) decays and contributions from $$\Upsilon (3S)$$ Υ ( 3 S ) and $$\Upsilon (2S)$$ Υ ( 2 S ) decays are taken into account. The transverse momentum dependent (TMD) gluon densities in a proton were derived from the Ciafaloni–Catani–Fiorani–Marchesini evolution equation and the Kimber-Martin–Ryskin prescription. Treating the non-perturbative color octet transitions in terms of multipole radiation theory, we extract the corresponding non-perturbative matrix elements for $$\Upsilon (1S)$$ Υ ( 1 S ) and $$\chi _b(1P)$$ χ b ( 1 P ) mesons from a combined fit to transverse momenta distributions measured at various LHC experiments. Then we apply the extracted values to investigate the polarization parameters $$\lambda _\theta $$ λ θ , $$\lambda _\phi $$ λ ϕ and $$\lambda _{\theta \phi }$$ λ θ ϕ , which determine the $$\Upsilon (1S)$$ Υ ( 1 S ) spin density matrix. Our predictions have a reasonably good agreement with the currently available Tevatron and LHC data within the theoretical and experimental uncertainties.

Vector Meson Production in Semi‐Inclusive π ‐ p Interactions

1974 ◽  
Author(s):  
A. Levy ◽  
D. Brick ◽  
M. Hodous ◽  
R. Hulsizer ◽  
V. Kistiakowsky ◽  
...  
Keyword(s):  
Vector Meson ◽  
Meson Production ◽  
Vector Meson Production

scholarly journals International Workshop: Meson Production at Intermediate and High Energies

2012 ◽  
Vol 349 ◽  
pp. 011001
Author(s):  
Giorgio Giardina ◽  
Fabio Bossi ◽  
Paolo Levi Sandri ◽  
Paolo Pedroni ◽  
Hartmut Schmieden
Keyword(s):  
International Workshop ◽  
Meson Production ◽  
High Energies
Sign in / Sign up

Export Citation Format

Share Document