6533b834fe1ef96bd129e1ba

RESEARCH PRODUCT

New extraction of color-octet NRQCD matrix elements from charmonium hadroproduction

M.a. Sanchis-lozanoM.a. Sanchis-lozano

subject

PhysicsNuclear and High Energy PhysicsParticle physicsLarge Hadron ColliderOctetBar (music)High Energy Physics::LatticeExtraction (chemistry)High Energy Physics::PhenomenologyFOS: Physical sciencesFísicaAtomic and Molecular Physics and OpticsGluonMatrix (mathematics)High Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)High Energy Physics::ExperimentSensitivity (control systems)Nuclear ExperimentEvent generator

description

We re-analyze Tavatron data on charmonium hadroproduction in the framework of the color-octet model implemented in the event generator PYTHIA taking into account initial-state radiation of gluons and Altarelli-Parisi evolution of final-state gluons fragmenting into $c\bar{c}$ pairs. We obtain new values for the color-octet matrix elements relevant to this production process. We discuss the sensitivity of our results to the transverse momentum lower cut-off employed in the generation to avoid the problematic $p_t{\to}0$ region, arguing about the reliability of our previous extraction of the NRQCD matrix elements for the $^3S_1^{(8)}$ and $^1S_0^{(8)}+^3P_J^{(8)}$ contributions. Finally we extrapolate to LHC energies to get predictions on the $J/\psi$ direct production rate.

10.1016/s0920-5632(00)00620-4http://hdl.handle.net/10550/43918