Dijet production, collision centrality and backgrounds in high-energy p-p collisions

Abstract

Two aspects of high-energy \pp collisions share common phenomenological elements: (a) A correlation between jet production and \pp centrality is suggested by the transverse partonic structure of hadrons inferred from deep-inelastic scattering data. (b) The {\em underlying event} (UE) is defined as the final-state particles complementary to a triggered high-energy dijet. An observable common to both topics is variation of so-called {\em transverse multiplicity} $N_{\perp }$ with a $p_{t,trig}$ dijet trigger. We test assumptions associated with \pp collision centrality and the UE. We determine the nature of the UE and explore the relation between jet production and \pp centrality. We use the {\em two-component model} (TCM) of spectra and correlations derived from 200 GeV \pp collisions to construct a simulated particle distribution on $(p_t,n_{ch})$ to predict the $N_{\perp }$ response to $p_{t,trig}$. The $p_t$ spectrum TCM combined in this analysis with measured minimum-bias \pp angular correlations suggests that the UE includes a substantial contribution from the triggered dijet in addition to the contribution from projectile fragmentation (beam-beam remnants). The jet contribution to $N_{\perp }$ may represent a universal large-angle base common to all dijets that extends across $2\pi$ azimuth. The analysis further suggests that \pp centrality is not controlled significantly by $p_{t,trig}$ but may be correlated to some extent with an imposed $n_{ch}$ condition, depending on the role of fluctuations. Future correlation studies may better determine the role of \pp centrality. These results may have implications for ongoing RHIC analysis and LHC searches for physics beyond the standard model.

17 pages, 12 figures

References in corpus (8)

• Interleaved Parton Showers and Tuning Prospects
• Transverse nucleon structure and diagnostics of hard parton-parton processes at LHC
• The multiplicity dependence of inclusive $p_t$ spectra from p-p collisions at $\sqrt{s}$ = 200 GeV
• Evolution of minimum-bias parton fragmentation in nuclear collisions
• Centrality evolution of $p_t$ and $y_t$ spectra from Au-Au collisions at $\sqrt{s_{NN}}=200$ GeV
• Extrapolating parton fragmentation to low $Q^2$ in $e^{+}$-$e^{-}$ collisions
• Parton fragment yields derived from minimum-bias jet angular correlations
• Azimuth Quadrupole Systematics in Au-Au Collisions

Cited by in corpus (10)

• A critical review of RHIC experimental results
• CCharge-multiplicity dependence of single-particle transverse-rapidity ${\mathbf{y}}_{\mathbf{t}}$ and pseudorapidity $\eta$ densities and 2D angular correlations from 200 GeV $p$-$p$ collisions
• Charged Hadron Multiplicity Distribution at Relativistic Heavy Ion Colliders
• Ensemble mean ${\mathbf{p}}_{\mathbf{t}}$ vs charged-hadron multiplicities in high energy nuclear collisions
• Two-component model of 2D trigger-associated hadron correlations on rapidity space ${\mathbf{y}}_{\mathbf{ta}}\times {\mathbf{y}}_{\mathbf{tt}}$ derived from 1D ${\mathbf{p}}_{\mathbf{t}}$ spectra for p-p collisions at $\sqrt{\mathbf{s}}=200$ GeV
• Charge-multiplicity and collision-energy dependence of $p_t$ spectra from $p$-$p$ collisions at the relativistic heavy-ion collider and large hadron collider
• Optimal modeling of 1D azimuth correlations in the context of Bayesian inference
• Comparing the PYTHIA Monte Carlo to a two-component (soft + hard) model of hadron production in high-energy p-p collisions
• PYTHIA and the preoccupied proton
• QCD prediction of jet structure in 2D trigger-associated momentum correlations and implications for multiple parton interactions