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Measurements of jet quenching using semi-inclusive hadron+jet distributions in pp and central Pb-Pb collisions at sNN=5.02 TeV

https://doi.org/10.1103/PhysRevC.110.014906

Acharya, S ; Adamová, D ; Aglieri_Rinella, G ; Agnello, M ; Agrawal, N ; Ahammed, Z ; Ahmad, S ; Ahn, S U ; Ahuja, I ; Akindinov, A ; et al ( July 2024 , Physical Review C)

The ALICE Collaboration reports measurements of the semi-inclusive distribution of charged-particle jets recoiling from a high transverse momentum (high $p_{T}$ ) charged hadron, in $p p$ and central Pb-Pb collisions at center-of-mass energy per nucleon–nucleon collision $\sqrt{s_{NN}} = 5.02$ TeV. The large uncorrelated background in central Pb-Pb collisions is corrected using a data-driven statistical approach which enables precise measurement of recoil jet distributions over a broad range in $p_{T, ch jet}$ and jet resolution parameter $R$ . Recoil jet yields are reported for $R = 0.2$ , 0.4, and 0.5 in the range $7 < p_{T, ch jet} < 140 GeV / c$ and $π / 2 < Δ φ < π$ , where $Δ φ$ is the azimuthal angular separation between hadron trigger and recoil jet. The low- $p_{T, ch jet}$ reach of the measurement explores unique phase space for studying jet quenching, the interaction of jets with the quark–gluon plasma generated in high-energy nuclear collisions. Comparison of $p_{T, ch jet}$ distributions from $p p$ and central Pb-Pb collisions probes medium-induced jet energy loss and intra-jet broadening, while comparison of their acoplanarity distributions explores in-medium jet scattering and medium response. The measurements are compared to theoretical calculations incorporating jet quenching.

<supplementary-material><permissions><copyright-statement>©2024 CERN, for the ALICE Collaboration</copyright-statement><copyright-year>2024</copyright-year><copyright-holder>CERN</copyright-holder></permissions></supplementary-material></sec> </div> <a href='#' class='show open-abstract' style='margin-left:10px;'>more »</a> <a href='#' class='hide close-abstract' style='margin-left:10px;'>« less</a> <div class="actions" style="padding-left:10px;"> <span class="reader-count"> Free, publicly-accessible full text available July 1, 2025</span> </div> </div><div class="clearfix"></div> </div> </li> <li> <div class="article item document" itemscope itemtype="http://schema.org/TechArticle"> <div class="item-info"> <div class="title"> <a href="https://par.nsf.gov/biblio/10554971-observation-medium-induced-yield-enhancement-acoplanarity-broadening-low-pt-jets-from-measurements-pp-central-pb-pb-collisions-snn" itemprop="url"> <span class='span-link' itemprop="name">Observation of Medium-Induced Yield Enhancement and Acoplanarity Broadening of Low- pT Jets from Measurements in pp and Central Pb-Pb Collisions at sNN=5.02 TeV</span> </a> </div> <div> <strong> <a class="misc external-link" href="https://doi.org/10.1103/PhysRevLett.133.022301" target="_blank" title="Link to document DOI">https://doi.org/10.1103/PhysRevLett.133.022301 <span class="fas fa-external-link-alt"></span></a> </strong> </div> <div class="metadata"> <span class="authors"> <span class="author" itemprop="author">Acharya, S</span> <span class="sep">; </span><span class="author" itemprop="author">Adamová, D</span> <span class="sep">; </span><span class="author" itemprop="author">Aglieri_Rinella, G</span> <span class="sep">; </span><span class="author" itemprop="author">Agnello, M</span> <span class="sep">; </span><span class="author" itemprop="author">Agrawal, N</span> <span class="sep">; </span><span class="author" itemprop="author">Ahammed, Z</span> <span class="sep">; </span><span class="author" itemprop="author">Ahmad, S</span> <span class="sep">; </span><span class="author" itemprop="author">Ahn, S U</span> <span class="sep">; </span><span class="author" itemprop="author">Ahuja, I</span> <span class="sep">; </span><span class="author" itemprop="author">Akindinov, A</span> <span class="sep">; </span><span class="author">et al</span></span> <span class="year">( <time itemprop="datePublished" datetime="2024-07-01">July 2024</time> , Physical Review Letters) </span> </div> <div style="cursor: pointer;-webkit-line-clamp: 5;" class="abstract" itemprop="description"> <p>The ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum (high<math display='inline'><mrow><msub><mrow><mi>p</mi></mrow><mrow><mi mathvariant='normal'>T</mi></mrow></msub></mrow></math>) hadron trigger in proton-proton and central Pb-Pb collisions at<math display='inline'><mrow><msqrt><mrow><msub><mrow><mi>s</mi></mrow><mrow><mi>NN</mi></mrow></msub></mrow></msqrt><mo>=</mo><mn>5.02</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math>. A data-driven statistical method is used to mitigate the large uncorrelated background in central Pb-Pb collisions. Recoil jet distributions are reported for jet resolution parameter<math display='inline'><mi>R</mi><mo>=</mo><mn>0.2</mn></math>, 0.4, and 0.5 in the range<math display='inline'><mrow><mn>7</mn><mo><</mo><msub><mrow><mi>p</mi></mrow><mrow><mi mathvariant='normal'>T</mi><mo>,</mo><mtext>jet</mtext></mrow></msub><mo><</mo><mn>140</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>/</mo><mi>c</mi></mrow></math>and trigger-recoil jet azimuthal separation<math display='inline'><mrow><mi>π</mi><mo>/</mo><mn>2</mn><mo><</mo><mrow><mi mathvariant='normal'>Δ</mi><mi>φ</mi></mrow><mo><</mo><mi>π</mi></mrow></math>. The measurements exhibit a marked medium-induced jet yield enhancement at low<math display='inline'><msub><mi>p</mi><mi mathvariant='normal'>T</mi></msub></math>and at large azimuthal deviation from<math display='inline'><mrow><mrow><mi mathvariant='normal'>Δ</mi><mi>φ</mi></mrow><mo>∼</mo><mi>π</mi></mrow></math>. The enhancement is characterized by its dependence on<math display='inline'><mi mathvariant='normal'>Δ</mi><mi>φ</mi></math>, which has a slope that differs from zero by<math display='inline'><mrow><mn>4.7</mn><mi>σ</mi></mrow></math>. Comparisons to model calculations incorporating different formulations of jet quenching are reported. These comparisons indicate that the observed yield enhancement arises from the response of the QGP medium to jet propagation.</p> <sec><title/><supplementary-material><permissions><copyright-statement>© 2024 CERN, for the ALICE Collaboration</copyright-statement><copyright-year>2024</copyright-year><copyright-holder>CERN</copyright-holder></permissions></supplementary-material></sec> </div> <a href='#' class='show open-abstract' style='margin-left:10px;'>more »</a> <a href='#' class='hide close-abstract' style='margin-left:10px;'>« less</a> <div class="actions" style="padding-left:10px;"> <span class="reader-count"> Free, publicly-accessible full text available July 1, 2025</span> </div> </div><div class="clearfix"></div> </div> </li> <li> <div class="article item document" itemscope itemtype="http://schema.org/TechArticle"> <div class="item-info"> <div class="title"> <a href="https://par.nsf.gov/biblio/10514236-observation-abnormal-suppression-f0-production-ppb-collisions-snn-tev" itemprop="url"> <span class='span-link' itemprop="name">Observation of abnormal suppression of f0(980) production in p–Pb collisions at sNN = 5.02 TeV</span> </a> </div> <div> <strong> <a class="misc external-link" href="https://doi.org/10.1016/j.physletb.2024.138665" target="_blank" title="Link to document DOI">https://doi.org/10.1016/j.physletb.2024.138665 <span class="fas fa-external-link-alt"></span></a> </strong> </div> <div class="metadata"> <span class="authors"> <span class="author" itemprop="author">Acharya, S</span> <span class="sep">; </span><span class="author" itemprop="author">Adamová, D</span> <span class="sep">; </span><span class="author" itemprop="author">Aglieri_Rinella, G</span> <span class="sep">; </span><span class="author" itemprop="author">Agnello, M</span> <span class="sep">; </span><span class="author" itemprop="author">Agrawal, N</span> <span class="sep">; </span><span class="author" itemprop="author">Ahammed, Z</span> <span class="sep">; </span><span class="author" itemprop="author">Ahmad, S</span> <span class="sep">; </span><span class="author" itemprop="author">Ahn, SU</span> <span class="sep">; </span><span class="author" itemprop="author">Ahuja, I</span> <span class="sep">; </span><span class="author" itemprop="author">Akindinov, A</span> <span class="sep">; </span><span class="author">et al</span></span> <span class="year">( <time itemprop="datePublished" datetime="2024-06-01">June 2024</time> , Physics Letters B) </span> </div> <div class="actions" style="padding-left:10px;"> <span class="reader-count"> Free, publicly-accessible full text available June 1, 2025</span> </div> </div><div class="clearfix"></div> </div> </li> <li> <div class="article item document" itemscope itemtype="http://schema.org/TechArticle"> <div class="item-info"> <div class="title"> <a href="https://par.nsf.gov/biblio/10512839-charm-bottom-quark-production-au+au-collisions-snn-gev" itemprop="url"> <span class='span-link' itemprop="name">Charm- and bottom-quark production in Au+Au collisions at sNN=200 GeV</span> </a> </div> <div> <strong> <a class="misc external-link" href="https://doi.org/10.1103/PhysRevC.109.044907" target="_blank" title="Link to document DOI">https://doi.org/10.1103/PhysRevC.109.044907 <span class="fas fa-external-link-alt"></span></a> </strong> </div> <div class="metadata"> <span class="authors"> <span class="author" itemprop="author">Abdulameer, N J</span> <span class="sep">; </span><span class="author" itemprop="author">Acharya, U</span> <span class="sep">; </span><span class="author" itemprop="author">Adare, A</span> <span class="sep">; </span><span class="author" itemprop="author">Aidala, C</span> <span class="sep">; </span><span class="author" itemprop="author">Ajitanand, N N</span> <span class="sep">; </span><span class="author" itemprop="author">Akiba, Y</span> <span class="sep">; </span><span class="author" itemprop="author">Alfred, M</span> <span class="sep">; </span><span class="author" itemprop="author">Apadula, N</span> <span class="sep">; </span><span class="author" itemprop="author">Asano, H</span> <span class="sep">; </span><span class="author" itemprop="author">Azmoun, B</span> <span class="sep">; </span><span class="author">et al</span></span> <span class="year">( <time itemprop="datePublished" datetime="2024-04-01">April 2024</time> , Physical Review C) </span> </div> <div class="actions" style="padding-left:10px;"> <span class="reader-count"> Free, publicly-accessible full text available April 1, 2025</span> </div> </div><div class="clearfix"></div> </div> </li> <li> <div class="article item document" itemscope itemtype="http://schema.org/TechArticle"> <div class="item-info"> <div class="title"> <a href="https://par.nsf.gov/biblio/10554975-systematic-study-flow-vector-fluctuations-snn-tev-pb-pb-collisions" itemprop="url"> <span class='span-link' itemprop="name">Systematic study of flow vector fluctuations in sNN=5.02 TeV Pb-Pb collisions</span> </a> </div> <div> <strong> <a class="misc external-link" href="https://doi.org/10.1103/PhysRevC.109.065202" target="_blank" title="Link to document DOI">https://doi.org/10.1103/PhysRevC.109.065202 <span class="fas fa-external-link-alt"></span></a> </strong> </div> <div class="metadata"> <span class="authors"> <span class="author" itemprop="author">Acharya, S</span> <span class="sep">; </span><span class="author" itemprop="author">Adamová, D</span> <span class="sep">; </span><span class="author" itemprop="author">Agarwal, A</span> <span class="sep">; </span><span class="author" itemprop="author">Aglieri_Rinella, G</span> <span class="sep">; </span><span class="author" itemprop="author">Aglietta, L</span> <span class="sep">; </span><span class="author" itemprop="author">Agnello, M</span> <span class="sep">; </span><span class="author" itemprop="author">Agrawal, N</span> <span class="sep">; </span><span class="author" itemprop="author">Ahammed, Z</span> <span class="sep">; </span><span class="author" itemprop="author">Ahmad, S</span> <span class="sep">; </span><span class="author" itemprop="author">Ahn, S U</span> <span class="sep">; </span><span class="author">et al</span></span> <span class="year">( <time itemprop="datePublished" datetime="2024-06-01">June 2024</time> , Physical Review C) </span> </div> <div style="cursor: pointer;-webkit-line-clamp: 5;" class="abstract" itemprop="description"> <p>Measurements of the<math><msub><mi>p</mi><mi mathvariant='normal'>T</mi></msub></math>-dependent flow vector fluctuations in Pb–Pb collisions at<math><mrow><msqrt><msub><mi>s</mi><mi>NN</mi></msub></msqrt><mo>=</mo><mn>5.02</mn><mspace width='0.16em'/><mi>TeV</mi></mrow></math>using azimuthal correlations with the ALICE experiment at the Large Hadron Collider are presented. A four-particle correlation approach [ALICE Collaboration, ] is used to quantify the effects of flow angle and magnitude fluctuations separately. This paper extends previous studies to additional centrality intervals and provides measurements of the<math><msub><mi>p</mi><mi mathvariant='normal'>T</mi></msub></math>-dependent flow vector fluctuations at<math><mrow><msqrt><msub><mi>s</mi><mi>NN</mi></msub></msqrt><mo>=</mo><mn>5.02</mn><mspace width='0.16em'/><mi>TeV</mi></mrow></math>with two-particle correlations. Significant<math><msub><mi>p</mi><mi mathvariant='normal'>T</mi></msub></math>-dependent fluctuations of the<math><msub><mover accent='true'><mi>V</mi><mo>⃗</mo></mover><mn>2</mn></msub></math>flow vector in Pb–Pb collisions are found across different centrality ranges, with the largest fluctuations of up to<math><mrow><mo>∼</mo><mn>15</mn><mo>%</mo></mrow></math>being present in the 5% most central collisions. In parallel, no evidence of significant<math><msub><mi>p</mi><mi mathvariant='normal'>T</mi></msub></math>-dependent fluctuations of<math><msub><mover accent='true'><mi>V</mi><mo>⃗</mo></mover><mn>3</mn></msub></math>or<math><msub><mover accent='true'><mi>V</mi><mo>⃗</mo></mover><mn>4</mn></msub></math>is found. Additionally, evidence of flow angle and magnitude fluctuations is observed with more than<math><mrow><mn>5</mn><mi>σ</mi></mrow></math>significance in central collisions. These observations in<math><mtext>Pb–Pb</mtext></math>collisions indicate where the classical picture of hydrodynamic modeling with a common symmetry plane breaks down. This has implications for hard probes at high<math><msub><mi>p</mi><mi mathvariant='normal'>T</mi></msub></math>, which might be biased by<math><msub><mi>p</mi><mi mathvariant='normal'>T</mi></msub></math>-dependent flow angle fluctuations of at least 23% in central collisions. Given the presented results, existing theoretical models should be reexamined to improve our understanding of initial conditions, quark–gluon plasma properties, and the dynamic evolution of the created system.</p> <sec><title/><supplementary-material><permissions><copyright-statement>©2024 CERN, for the ALICE Collaboration</copyright-statement><copyright-year>2024</copyright-year><copyright-holder>CERN</copyright-holder></permissions></supplementary-material></sec> </div> <a href='#' class='show open-abstract' style='margin-left:10px;'>more »</a> <a href='#' class='hide close-abstract' style='margin-left:10px;'>« less</a> <div class="actions" style="padding-left:10px;"> <span class="reader-count"> Free, publicly-accessible full text available June 1, 2025</span> </div> </div><div class="clearfix"></div> </div> </li> </ol> <div id="pagination-lower" style=""> <div class="pull-right" style="line-height: 30px;"> <div class="btn-group pagination nomargin"> <a href="#" class="btn btn-sm btn-default noborderradius" disabled="disabled">«<span class="hidden-xs"> Prev</span></a> <a class="dropdown-toggle btn btn-sm btn-default paging-dropdown hidden-xs noborderradius" href="#" data-toggle="dropdown"><span class="caret"></span><span class="sr-only">Select page number</span></a> <div class="dropdown-menu pull-right paging-slider-dropdown" style="padding: 15px;"> <small> <div class="text-muted" style="line-height:20px;"><label for="pagination-sel-sptag-2">Go to page: <span class="paging-target">1</span> of <span class="paging-max">41</span></label></div> <div> <table> <tr> <td valign="top"> <input id="pagination-sel-sptag-2" data-range="" value="1" min="1" max="41" name="pagination-sel" type="range" class="pagination-sel noborderradius" style="height:26px;padding:0px;margin-right:5px; 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