Centrality-Dependent Modification of Jet-Production Rates in Deuteron-Gold Collisions at √[s(NN)]=200 GeV

Area of Science:

• High-energy nuclear physics
• Particle physics
• Quantum chromodynamics

Background:

• Understanding the properties of matter under extreme conditions, such as the quark-gluon plasma, is a key goal in high-energy nuclear physics.
• Jet production in high-energy collisions serves as a crucial probe for studying the medium created in these interactions.

Purpose of the Study:

• To measure jet production rates in proton-proton (p+p) and deuteron-gold (d+Au) collisions at a center-of-mass energy per nucleon pair of 200 GeV.
• To investigate the role of initial state effects and final state interactions on jet production by comparing results from different collision systems and centralities.

Main Methods:

• Jets were reconstructed using the anti-k$_{t}$ algorithm with a radius parameter R=0.3 from energy deposits in the electromagnetic calorimeter and charged tracks.
• Jet transverse momentum (p$_{T}$) spectra were corrected for detector response.
• Measurements were performed within a pseudorapidity acceptance of |η|<0.3 for jets with 12 < p$_{T}$ < 50 GeV/c.

Main Results:

• The nuclear-modification factor (R$_{dAu}$) for inclusive jet production in minimum bias (0%-100%) d+Au collisions was found to be consistent with unity.
• Centrality-selected R$_{dAu}$ values and central-to-peripheral ratios (R$_{CP}$) exhibited significant, transverse momentum-dependent deviations from unity.
• These deviations indicate a complex interplay between initial state effects and final state interactions in d+Au collisions.

Conclusions:

• The R$_{dAu}$ results constrain the contribution of initial state effects to jet production, suggesting they are not the dominant factor for inclusive jets.
• The observed deviations in centrality-selected R$_{dAu}$ and R$_{CP}$ challenge conventional models that attempt to link hard-process rates with soft-particle production.
• Further theoretical and experimental efforts are needed to fully understand the dynamics of jet production and its interaction with the nuclear medium.