Inhomogeneous shadowing effects on J/psi production in dA collisions

Area of Science:

• Nuclear Physics
• High-Energy Particle Physics

Background:

• Shadowing describes the reduction in nuclear parton distribution functions at small Bjorken-x.
• Understanding shadowing is crucial for interpreting particle production in high-energy nuclear collisions.

Purpose of the Study:

• To study the impact of spatially homogeneous and inhomogeneous shadowing on J/psi production.
• To explore methods for measuring shadowing and its spatial dependence using deuterium-nucleus (dA) collisions.
• To compare shadowing effects in dA collisions with those in nucleus-nucleus (AA) collisions.

Main Methods:

• Analyzing J/psi production in deuterium-gold (dAu) and deuterium-lead (dPb) collisions.
• Comparing central and peripheral dA collisions to probe shadowing's spatial dependence.
• Utilizing gray protons from heavy ion breakup and non-interacting deuterium nucleons for event selection.

Main Results:

• Inhomogeneous shadowing significantly affects central dA collisions.
• The observed effect of inhomogeneous shadowing in central dA collisions is larger than anticipated for central AA collisions.
• Results are presented for dAu collisions at sqrt[s(NN)]=200 GeV and dPb collisions at sqrt[s(NN)]=6.2 TeV.

Conclusions:

• Spatial dependence of shadowing plays a critical role in J/psi production in dA collisions.
• dA collisions offer a unique probe for studying shadowing phenomena, distinct from AA collisions.
• The findings provide valuable insights into nuclear matter structure at high energies.