scholarly journals Revisiting the production of $$J/\psi $$ pairs at the LHC

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
A. A. Prokhorov ◽  
A. V. Lipatov ◽  
M. A. Malyshev ◽  
S. P. Baranov
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Effective Cross Section ◽  
Lhcb Collaboration ◽  
Kinematical Region ◽  
Final States ◽  
Scattering Mechanism ◽  
Initial State ◽  
Double Parton Scattering ◽  
Parton Scattering

AbstractWe consider the prompt double $$J/\psi $$ J / ψ production in pp collisions at the LHC in the framework of $$k_T$$ k T -factorization QCD approach. Using the fragmentation mechanism, we evaluate the color octet contributions to the production cross sections taking into account the combinatorial effects of multiple gluon radiation in the initial state driven by the Ciafaloni–Catani–Fiorani–Marchesini evolution equation. We demonstrate the importance of these contributions in a certain kinematical region covered by the CMS and ATLAS measurements. On the other hand, the experimental data taken by the LHCb Collaboration at forward rapidities and moderate transverse momenta can be described well by $${{{\mathcal {O}}}}(\alpha _s^4)$$ O ( α s 4 ) color singlet terms and contributions from the double parton scattering mechanism. The extracted value of the effective cross section is compatible with many other estimations based on different final states.

scholarly journals DPS mechanism for associated $$c\bar{c} b\bar{b}$$ production in AA UPCs

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Edgar Huayra ◽  
Emmanuel G. de Oliveira ◽  
Roman Pasechnik
Keyword(s):  
Production Process ◽  
Cross Section ◽  
Photon Energy ◽  
Cross Sections ◽  
Effective Cross Section ◽  
Double Parton Scattering ◽  
Quark Pairs ◽  
Numerical Predictions ◽  
Energy Dependent ◽  
Parton Scattering

Abstract We discuss the associated $$c\bar{c}$$cc¯ and $$b\bar{b}$$bb¯ quark pairs production in the double-parton scattering (DPS) process in ultraperipheral (UPCs) AA collisions. We derive an analogue of the inclusive DPS pocket formula and the photon-energy dependent effective cross section considering an overlap between the hard SPS scatterings. We provide numerical predictions for the DPS cross sections for the $$c\bar{c}b\bar{b}$$cc¯bb¯ production process at the typical energies of AA UPCs at the LHC and FCC colliders and also characterize the A dependence of the total UPC DPS cross section.

scholarly journals Heavy quark production in pA collisions: The double parton scattering contribution

2018 ◽  
Vol 33 (25) ◽  
pp. 1850141 ◽  
Author(s):  
E. R. Cazaroto ◽  
V. P. Gonçalves ◽  
F. S. Navarra
Keyword(s):  
Heavy Quark ◽  
Cross Sections ◽  
Lhcb Collaboration ◽  
Heavy Quark Production ◽  
Double Parton Scattering ◽  
High Energies ◽  
Quark Production ◽  
Scattering Contribution ◽  
Saturation Effects ◽  
Parton Scattering

In this paper, we estimate the double parton scattering (DPS) contribution for the heavy quark production in pA collisions at the LHC. The cross-sections for the charm and bottom production are estimated using the dipole approach, taking into account the saturation effects, which are important for high energies and for the scattering with a large nucleus. We compare the DPS contribution with the single parton scattering one and demonstrate that in the case of charm production, both are similar in the kinematical range probed by the LHC. Predictions for the rapidity range analyzed by the LHCb Collaboration are also presented. Our results indicate that the study of the DPS contribution for the heavy quark production in pPb collisions at the LHC is feasible and can be useful to probe the main assumptions of the approach.

MATRIX EFFECTS ON K-SHELL IONIZATION CROSS SECTIONS IN Al/Si ALLOYS

2002 ◽  
Vol 12 (01n02) ◽  
pp. 1-5
Author(s):  
M. NEKAB ◽  
Ch. HEITZ
Keyword(s):  
Cross Sections ◽  
Matrix Effects ◽  
Production Cross ◽  
Heavy Ion ◽  
Double Scattering ◽  
Scattering Mechanism ◽  
Ionization Cross ◽  
X Ray ◽  
Ionization Cross Sections ◽  
Shell Ionization

Thick targets consisting in Al/Si alloys were bombarded with 1.0 to 5.0 MeV Ar ions. The K X-ray production cross sections were deduced from the measured yields by using the Merzbacher-Lewis formula extended to heavy ion bombardment. The density dependence on the K X-ray production cross sections of Al and Si was observed. This phenomena can be interpreted within the molecular orbital double-scattering mechanism.

scholarly journals Probing double parton scattering via associated open charm and bottom production in ultraperipheral pA collisions

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Edgar Huayra ◽  
Emmanuel G. de Oliveira ◽  
Roman Pasechnik
Keyword(s):  
Effective Cross Section ◽  
High Energy ◽  
Direct Access ◽  
Photon Momentum ◽  
Double Parton Scattering ◽  
Quark Pairs ◽  
Associated Production ◽  
Phenomenological Studies ◽  
Theoretical Predictions ◽  
Parton Scattering

Abstract In this article, we propose a novel channel for phenomenological studies of the double-parton scattering (DPS) based upon associated production of charm $$c{\bar{c}}$$cc¯ and bottom $$b{\bar{b}}$$bb¯ quark pairs in well-separated rapidity intervals in ultraperipheral high-energy proton–nucleus collisions. This process provides direct access to the double-gluon distribution in the proton at small-x and enables one to test the factorized DPS pocket formula. We have made the corresponding theoretical predictions for the DPS contribution to this process at typical LHC energies and beyond and we compute the energy-independent (but photon momentum fraction dependent) effective cross section.

scholarly journals Production of quarkonium pairs in high-energy proton-proton collisions

2019 ◽  
Vol 199 ◽  
pp. 01021 ◽  
Author(s):  
Wolfgang Schäfer
Keyword(s):  
Pair Production ◽  
Cross Sections ◽  
High Energy ◽  
Open Problems ◽  
Proton Proton ◽  
Proton Collisions ◽  
Double Parton Scattering ◽  
Parton Scattering ◽  
To Receive ◽  
Proton Proton Collisions

Recently there has been much interest in the pair production of quarkonia (charmonia, bottomonia). There are two main motivations behind these studies: first, these processes may help to differentiate between different proposed production mechanisms via color-octet and color-singlet QQ̄ -pair production. Second, the production of quarkonium pairs is expected to receive an important contribution from double parton scattering (DPS) processes. There remain a number of open problems, especially with the CMS and ATLAS data. In the kinematics of these experiments, the leading order of $O\left( {\alpha _S^4} \right)$ is clearly not sufficient. The double parton scattering (DPS) contribution was claimed to be large or even dominant in some corners of the phase space, when the rapidity distance Δy between two J/ψ mesons is large. However the effective cross sections σeff found from empirical analyses are about a factor 2.5 smaller than the usually accepted σeff = 15 mb. Here we discuss, which single-parton-scattering mechanisms can mimic the behavior of DPS induced production. Here especially the production of χ-pairs is important.

scholarly journals Double parton scattering: A study of the effective cross section within a Light-Front quark model

2016 ◽  
Vol 752 ◽  
pp. 40-45 ◽  
Author(s):  
Matteo Rinaldi ◽  
Sergio Scopetta ◽  
Marco Traini ◽  
Vicente Vento
Keyword(s):  
Quark Model ◽  
Cross Section ◽  
Effective Cross Section ◽  
Light Front ◽  
Double Parton Scattering ◽  
Parton Scattering
Sign in / Sign up

Export Citation Format

Share Document