1 Ocak 2016 Dergi makalesi Açık Erişim

CERN İşbirliği

Citation Style Language JSON

{
  "DOI": "10.1016/j.physletb.2016.10.048", 
  "abstract": "<p>We present measurements of two-particle correlations with neutral pion trigger particles of transverse momenta $8&lt;{p}_{T}^{\\mathrm{trig}}&lt;16\\text{}\\text{GeV}/c$ and associated charged particles of $0.5&lt;{p}_{T}^{\\mathrm{assoc}}&lt;10\\text{}\\text{GeV}/c$ versus the azimuthal angle difference \u0394\u03c6 at midrapidity in pp and central Pb\u2013Pb collisions at $\\sqrt{{s}_{\\mathrm{NN}}}=2.76\\text{TeV}$ with ALICE. The new measurements exploit associated charged hadrons down to $0.5\\text{}\\text{GeV}/c$, which significantly extends our previous measurement that only used charged hadrons above $3\\text{}\\text{GeV}/c$. After subtracting the contributions of the flow background, ${v}_{2}$ to ${v}_{5}$, the per-trigger yields are extracted for $|\\Delta \\phi |&lt;0.7$ on the near and for $|\\Delta \\phi -\\pi |&lt;1.1$ on the away side. The ratio of per-trigger yields in Pb\u2013Pb to those in pp collisions, ${I}_{\\mathrm{AA}}$, is measured on the near and away side for the $0\\text{\u2013}10\\text{%}$ most central Pb\u2013Pb collisions. On the away side, the per-trigger yields in Pb\u2013Pb are strongly suppressed to the level of ${I}_{\\mathrm{AA}}\\approx 0.6$ for ${p}_{T}^{\\mathrm{assoc}}&gt;3\\text{}\\text{GeV}/c$, while with decreasing momenta an enhancement develops reaching about 5 at low ${p}_{T}^{\\mathrm{assoc}}$. On the near side, an enhancement of ${I}_{\\mathrm{AA}}$ between 1.2 at the highest to 1.8 at the lowest ${p}_{T}^{\\mathrm{assoc}}$ is observed. The data are compared to parton-energy-loss predictions of the JEWEL and AMPT event generators, as well as to a perturbative QCD calculation with medium-modified fragmentation functions. All calculations qualitatively describe the away-side suppression at high ${p}_{T}^{\\mathrm{assoc}}$. Only AMPT captures the enhancement at low ${p}_{T}^{\\mathrm{assoc}}$, both on the near and away side. However, it also underpredicts ${I}_{\\mathrm{AA}}$ above $5\\text{GeV/}c$, in particular on the near-side.</p>", 
  "author": [
    {
      "family": "CERN \u0130\u015fbirli\u011fi"
    }
  ], 
  "container_title": "Physics Letters B", 
  "id": "107601", 
  "issued": {
    "date-parts": [
      [
        2016, 
        1, 
        1
      ]
    ]
  }, 
  "title": "Jet-like correlations with neutral pion triggers in pp and central Pb\u2013Pb collisions at 2.76 TeV", 
  "type": "article-journal", 
  "volume": "763 C"
}