Measurement of medium-induced acoplanarity in central Au-Au and pp collisions at $\sqrt{s_{\mathrm{NN}}}=200$ GeV using direct-photon+jet and ${\pi }^0$+jet correlations

Abstract

The STAR Collaboration reports measurements of acoplanarity using semi--inclusive distributions of charged--particle jets recoiling from direct photon and ${\pi }^0$ triggers, in central Au+Au and $pp$ collisions at $\sqrt{s_{\mathrm{NN}}}=200$ GeV. Significant medium--induced acoplanarity broadening is observed for large but not small recoil jet resolution parameter, corresponding to recoil jet yield enhancement up to a factor of $\approx 20$ for trigger--recoil azimuthal separation far from $\pi$. This phenomenology is indicative of the response of the Quark--Gluon Plasma to excitation, but not the scattering of jets off of its quasiparticles. The measurements are not well--described by current theoretical models which incorporate jet quenching.

arXiv commentSubmitted to PRL; 3 figures+1 figure in End Matter, accepted by PRC

References in corpus (41)

• FastJet user manual
• Collective flow and viscosity in relativistic heavy-ion collisions
• The equation of state in (2+1)-flavor QCD
• Full result for the QCD equation of state with 2+1 flavors
• Pileup subtraction using jet areas
• Heavy Ion Collisions: The Big Picture, and the Big Questions
• Observation and studies of jet quenching in PbPb collisions at nucleon-nucleon center-of-mass energy = 2.76 TeV
• The QCD Equation of State to $\mathcal{O}({\mu }_B^6)$ from Lattice QCD
• The QCD phase transition with physical-mass, chiral quarks
• The theory and phenomenology of perturbative QCD based jet quenching
• Multi-system Bayesian constraints on the transport coefficients of QCD matter
• Jet momentum dependence of jet quenching in PbPb collisions at sqrt(sNN)=2.76 TeV
• Studies of jet quenching using isolated-photon + jet correlations in PbPb and pp collisions at sqrt(s[NN]) = 2.76 TeV
• A Hybrid Strong/Weak Coupling Approach to Jet Quenching
• Longitudinal double-spin asymmetry and cross section for inclusive jet production in polarized proton collisions at sqrt(s) = 200 GeV
• A Monte Carlo Model for 'Jet Quenching'
• JEWEL 2.0.0 - Directions for Use
• Heavy quarks and jets as probes of the QGP
• Thermal photons as a quark-gluon plasma thermometer revisited
• Transverse Momentum Broadening and the Jet Quenching Parameter, Redux
• Angular Structure of Jet Quenching Within a Hybrid Strong/Weak Coupling Model
• Measurement and QCD analysis of double-differential inclusive jet cross-sections in pp collisions at sqrt(s) = 8 TeV and ratios to 2.76 and 7 TeV
• Measurement of jet quenching with semi-inclusive hadron-jet distributions in central Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Measurements of jet quenching with semi-inclusive hadron+jet distributions in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV
• Measurement of the inclusive differential jet cross section in pp collisions at $\sqrt{s}$ = 2.76 TeV
• Direct real photons in relativistic heavy ion collisions
• Probing Transverse Momentum Broadening via Dihadron and Hadron-jet Angular Correlations in Relativistic Heavy-ion Collisions
• Soft Gluon Resummations in Dijet Azimuthal Angular Correlations at the Collider
• Study of jet quenching with Z+jet correlations in PbPb and pp collisions at sqrt(s[NN]) = 5.02 TeV
• Momentum Broadening in Weakly Coupled Quark-Gluon Plasma (with a view to finding the quasiparticles within liquid quark-gluon plasma)
• Measurement of the inclusive jet cross-section in proton-proton collisions at $\sqrt{s}=7$ TeV using 4.5 fb${}^{-1}$ of data with the ATLAS detector
• Study of jet quenching with isolated-photon+jet correlations in PbPb and pp collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}=$ 5.02 TeV
• A Simultaneous Description of Hadron and Jet Suppression in Heavy Ion Collisions
• Longitudinal double-spin asymmetry for inclusive jet and dijet production in $pp$ collisions at $\sqrt{s}=510$ GeV
• Jet-like Correlations with Direct-Photon and Neutral-Pion Triggers at $\sqrt{s_{{}_{NN}}}=200$ GeV
• Decomposing transverse momentum balance contributions for quenched jets in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
• Molière Scattering in Quark-Gluon Plasma: Finding Point-Like Scatterers in a Liquid
• Measurement of the cross section and longitudinal double-spin asymmetry for di-jet production in polarized $pp$ collisions at $\sqrt{s}$ = 200 GeV
• Observation of medium-induced yield enhancement and acoplanarity broadening of low-$p_{\mathrm{T}}$ jets from measurements in pp and central Pb$-$Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Measurements of jet quenching using semi-inclusive hadron+jet distributions in pp and central Pb$-$Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Search for quasi-particle scattering in the quark-gluon plasma with jet splittings in pp and Pb$-$Pb collisions at $\sqrt{{\text{s}}_{\mathrm{NN}}}=5.02$ TeV

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