scholarly journals Quarkonium Production at Z0 and in ϒ(1S) Decay

1997 ◽  
Vol 12 (22) ◽  
pp. 3931-3940
Author(s):  
Kingman Cheung ◽  
Wai-Yee Keung ◽  
Tzu Chiang Yuan
Keyword(s):  
Color Singlet ◽  
Fixed Target ◽  
Production Rates ◽  
Fixed Target Experiments ◽  
Color Octet ◽  
Quarkonium Production ◽  
Color Octet Mechanism

The conventional color-singlet model was challenged by the recent data on quarkonium production. Discrepancies in production rates were observed at the Tevatron, at LEP, and in fixed-target experiments. The newly advocated color-octet mechanism provides a plausible solution to the anomalous quarkonium production observed at the Tevatron. The color-octet mechanism should also affect other quarkonium production channels. In this paper we will summarize the studies of quarkonium production in Z0 and ϒ decays.

J/ψ-PRODUCTION MECHANISMS AND DETERMINATION OF THE GLUON DENSITY AT HERA

1992 ◽  
Vol 07 (32) ◽  
pp. 7955-7988 ◽  
Author(s):  
H. JUNG ◽  
G.A. SCHULER ◽  
J. TERRON
Keyword(s):  
Gluon Fusion ◽  
Gluon Density ◽  
Color Singlet ◽  
Fixed Target ◽  
Fixed Target Experiments ◽  
Diffractive Production ◽  
Production Mechanisms ◽  
Inelastic Processes

We discuss photo- and leptoproduction of J/ψ mesons at energies ranging from those of fixed-target experiments up to those of HERA. Elastic and diffractive production as well as various inelastic processes are studied. We investigate the range in which J/ψ production is described by photon-gluon fusion in the color-singlet model. We show how inelastic J/ψ production at HERA can be used to extract the gluon density. We estimate an accessible range of 3×10−4<x<0.1 and discuss sources of errors in the reconstruction of the gluon density at HERA.

scholarly journals Quarkonium Suppression from Coherent Energy Loss in Fixed-Target Experiments Using LHC Beams

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
François Arleo ◽  
Stéphane Peigné
Keyword(s):  
Energy Loss ◽  
Nuclear Matter ◽  
Center Of Mass ◽  
High Energy ◽  
Fixed Target ◽  
Cold Nuclear Matter ◽  
Fixed Target Experiments ◽  
Quarkonium Production ◽  
Nuclear Modification Factors ◽  
Target Experiment

Quarkonium production in proton-nucleus collisions is a powerful tool to disentangle cold nuclear matter effects. A model based on coherent energy loss is able to explain the available quarkonium suppression data in a broad range of rapidities, from fixed-target to collider energies, suggesting coherent energy loss in cold nuclear matter to be the dominant effect in quarkonium suppression in p-A collisions. This could be further tested in a high-energy fixed-target experiment using a proton or nucleus beam. The nuclear modification factors ofJ/ψandΥas a function of rapidity are computed in p-A collisions ats=114.6 GeV, and in p-Pb and Pb-Pb collisions ats=72 GeV. These center-of-mass energies correspond to the collision on fixed-target nuclei of 7 TeV protons and 2.76 TeV (per nucleon) lead nuclei available at the LHC.

scholarly journals ηQ Meson Photoproduction in Ultrarelativistic Heavy Ion Collisions

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Gong-Ming Yu ◽  
Gao-Gao Zhao ◽  
Zhen Bai ◽  
Yan-Bing Cai ◽  
Hai-Tao Yang ◽  
...  
Keyword(s):  
Heavy Ion Collisions ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Heavy Quarkonium ◽  
Color Singlet ◽  
Initial State ◽  
Color Octet ◽  
Ion Collisions ◽  
The Matrix

The transverse momentum distributions for inclusive ηc,b meson described by gluon-gluon interactions from photoproduction processes in relativistic heavy ion collisions are calculated. We considered the color-singlet (CS) and color-octet (CO) components within the framework of Nonrelativistic Quantum Chromodynamics (NRQCD) in the production of heavy quarkonium. The phenomenological values of the matrix elements for the color-singlet and color-octet components give the main contribution to the production of heavy quarkonium from the gluon-gluon interaction caused by the emission of additional gluon in the initial state. The numerical results indicate that the contribution of photoproduction processes cannot be negligible for midrapidity in p-p and Pb-Pb collisions at the Large Hadron Collider (LHC) energies.

scholarly journals Feasibility Studies for Quarkonium Production at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC)

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
L. Massacrier ◽  
B. Trzeciak ◽  
F. Fleuret ◽  
C. Hadjidakis ◽  
D. Kikola ◽  
...  
Keyword(s):  
Feasibility Studies ◽  
Fixed Target ◽  
Detection Techniques ◽  
Target Mode ◽  
Quarkonium Production ◽  
Target Experiment ◽  
Conventional Detection ◽  
Fixed Target Experiment

Being used in the fixed-target mode, the multi-TeV LHC proton and lead beams allow for studies of heavy-flavour hadroproduction with unprecedented precision at backward rapidities, far negative Feynman-x, using conventional detection techniques. At the nominal LHC energies, quarkonia can be studied in detail inp+p,p+d, andp+Acollisions atsNN≃115 GeV and in Pb +pand Pb +Acollisions atsNN≃72 GeV with luminosities roughly equivalent to that of the collider mode that is up to 20 fb−1 yr−1inp+pandp+dcollisions, up to 0.6 fb−1 yr−1inp+Acollisions, and up to 10 nb−1 yr−1in Pb +Acollisions. In this paper, we assess the feasibility of such studies by performing fast simulations using the performance of a LHCb-like detector.

scholarly journals Interactions of Beams with Surroundings

2020 ◽  
pp. 183-203
Author(s):  
M. Brugger ◽  
H. Burkhardt ◽  
B. Goddard ◽  
F. Cerutti ◽  
R. G. Alia
Keyword(s):  
High Energy Physics ◽  
High Energy ◽  
Fixed Target ◽  
Fixed Target Experiments ◽  
Secondary Particles ◽  
Radiation Sources ◽  
Residual Gas ◽  
The Impact ◽  
High Energy Particles ◽  
Energy Physics

AbstractWith the exceptions of Synchrotron Radiation sources, beams of accelerated particles are generally designed to interact either with one another (in the case of colliders) or with a specific target (for the operation of Fixed Target experiments, the production of secondary beams and for medical applications). However, in addition to the desired interactions there are unwanted interactions of the high energy particles which can produce undesirable side effects. These interactions can arise from the unavoidable presence of residual gas in the accelerator vacuum chamber, or from the impact of particles lost from the beam on aperture limits around the accelerator, as well as the final beam dump. The wanted collisions of the beams in a collider to produce potentially interesting High Energy Physics events also reduces the density of the circulating beam and can produce high fluxes of secondary particles.

scholarly journals Color-octet quarkonium production at the Z pole

1995 ◽  
Author(s):  
K. Cheung ◽  
W.Y. Keung ◽  
T.C. Yuan
Keyword(s):  
Color Octet ◽  
Quarkonium Production
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