Energy losses in the black disc regime and correlation effects in the STAR forward pion production in dAu collisions

Abstract

We argue that in the small x processes, in the black disc QCD regime (BDR) a very forward parton propagating through the nuclear matter should loose a significant and increasing with energy and atomic number fraction of its initial energy as a result of dominance of inelastic interactions, causality and energy-momentum conservation. We evaluate these energy losses and find them to lead to the significant suppression of the forward jet production in the central NA collisions at collider energies with a moderate suppression of recoiling jet at central rapidities. We confront our expectations with the recent RHIC data of the STAR collaboration on the probability, $P$, for emission of at least one fast hadron at a central rapidity in association with production of a very forward high $p_t$ neutral pion in $pp$ and $dAu$ collisions. We calculate the A-dependence of $P$, and find that the data imply a strong suppression of leading pion production at central impact parameters. We also conclude that production of recoil jets in the hard subprocess is not suppressed providing further evidence for the dominance of peripheral collisions. Both features of the data are consistent with the onset of BDR. We suggest new phenomena and new observables to investigate BDR at RHIC and LHC.

arXiv comment18 pages,final text to be published in Phys.Lett.B, evaluation of the fractional energy energy losses in the black disk regime is ellaborated

References in corpus (28)

• Saturation Effects in Deep Inelastic Scattering at low $Q^2$ and its Implications on Diffraction
• Radiative energy loss of high energy quarks and gluons in a finite volume quark-gluon plasma
• BFKL pomeron in the next-to-leading approximation
• Energy Scale(s) and Next-to-leading BFKL Equation
• Non-Abelian Energy Loss at Finite Opacity
• Evolution of the nuclear modification factors with rapidity and centrality in d+Au collisions at $\sqrt{s_{NN}} = 200 GeV
• Cronin Effect and High-p_T Suppression in pA Collisions
• Transverse Momentum Spectra in Au+Au and d+Au Collisions at $\sqrt{s_{NN}}$=200 GeV and the Pseudorapidity Dependence of High p${}_T$ Suppression
• Parton saturation and N_part scaling of semi--hard processes in QCD
• Next-to-leading order QCD corrections to high-p_T pion production in longitudinally polarized pp collisions
• Coherent Nuclear Diffractive Production of Minijets - Illuminating Color Transparency
• The BFKL Equation at Next-to-Leading Order and Beyond
• Coherent QCD multiple scattering in proton-nucleus collisions
• Geometric scaling violations in the central rapidity region of d+Au collisions at RHIC
• Interactions of Reggeized Gluons in the Möbius Representation
• Dijet production as a centrality trigger for p-p collisions at CERN LHC
• Small-x Physics: From HERA to LHC and beyond
• Nuclear Modification Factors for Hadrons At Forward and Backward Rapidities in Deuteron-Gold Collisions at sqrt(s_NN) = 200 GeV
• Observations on dA scattering at forward rapidities
• Interaction of small size wave packet with hadron target
• Next-to-leading order QCD corrections to one hadron-production in polarized pp collisions at RHIC
• Revealing the black-body regime of small-x deep-inelastic scattering through final-state signals
• Constraints on quark energy loss from Drell-Yan data
• Azimuthal Angle Correlations for Rapidity Separated Hadron Pairs in d+Au Collisions at sqrt(s_NN) = 200 GeV
• Proton breakup in high-energy pA collisions from perturbative QCD
• Ion induced quark-gluon implosion
• Diffraction at HERA, Color Opacity and Nuclear Shadowing
• The casuality and/or energy-momentum conservation constraints on QCD amplitudes in small x regime

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• Azimuthal correlations of forward di-hadrons in d+Au collisions at RHIC in the Color Glass Condensate
• Single Inclusive Hadron Production at RHIC and the LHC from the Color Glass Condensate
• Leading twist nuclear shadowing phenomena in hard processes with nuclei
• Suppression of back-to-back hadron pairs at forward rapidity in d+Au Collisions at sqrt(s_NN)=200 GeV
• Particle Production at High Energy and Large Transverse Momentum - "The Hybrid Formalism" Revisited
• High Gluon Densities in Heavy Ions Collisions
• Forward di-hadron back-to-back correlations in $\mathbf{pA}$ collisions from rcBK evolution
• Hadron production in pA collisions at the LHC from the Color Glass Condensate
• Multiple parton interactions and forward double pion production in pp and dA scattering
• Single Spin Asymmetry Scaling in the Forward Rapidity Region at RHIC
• Extra Spin Asymmetries From the Breakdown of TMD-Factorization in Hadron-Hadron Collisions
• The initial state of heavy-ion collisions
• Forward dijets in high-energy collisions: evolution of QCD n-point functions beyond the dipole approximation
• Evidence for Nonlinear Gluon Effects in QCD and their $A$ Dependence at STAR
• Parton energy loss in high energy hard forward processes in proton-nucleus collisions
• Impact of fully coherent energy loss on heavy meson production in pA collisions
• Heavy-flavor electron-muon correlations in $p$$+$$p$ and $d$+Au collisions at $\sqrt{s_{{}_{NN}}}$ = 200 GeV
• Baryon Stopping in Proton-Nucleus Collisions
• Fully coherent energy loss effects on light hadron production in pA collisions
• The physics potential of proton-nucleus collisions at the TeV scale
• Single and double inclusive particle production in d+Au collisions at RHIC, leading twist and beyond
• Large t diffractive rho-meson photoproduction with target dissociation in ultraperipheral pA and AA collisions at LHC
• Cold nuclear matter physics at forward rapidities from d+Au collisions in PHENIX
• Leading twist shadowing, black disk regime and forward hadron production