Pseudorapidity dependence of the anisotropic flow of charged particles in Pb-Pb collisions at
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- 作者：ALICE Collaboration
- 刊名：Physics Letters B
- 出版年：2016
- 出版时间：10 November 2016
- 年：2016
- 卷：762
- 期：Complete
- 页码：376-388
- 全文大小：1662 K
文摘
We present measurements of the elliptic (pan id="mmlsi2" class="mathmlsrc">pan class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316303586&_mathId=si2.gif&_user=111111111&_pii=S0370269316303586&_rdoc=1&_issn=03702693&md5=9ca06101309bad52b1ff201bcbd21958" title="Click to view the MathML source">v2 pan>pan class="mathContainer hidden">pan class="mathCode"><math altimg="si2.gif" overflow="scroll"><msub><mrow><mi mathvariant="normal">vmi>mrow><mrow><mn>2mn>mrow>msub>math> pan> pan> pan>), triangular (pan id="mmlsi3" class="mathmlsrc">pan class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316303586&_mathId=si3.gif&_user=111111111&_pii=S0370269316303586&_rdoc=1&_issn=03702693&md5=4285627d45ccdda4c0d45ff7ed4a256b" title="Click to view the MathML source">v3 pan>pan class="mathContainer hidden">pan class="mathCode"><math altimg="si3.gif" overflow="scroll"><msub><mrow><mi mathvariant="normal">vmi>mrow><mrow><mn>3mn>mrow>msub>math> pan> pan> pan>) and quadrangular (pan id="mmlsi4" class="mathmlsrc">pan class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316303586&_mathId=si4.gif&_user=111111111&_pii=S0370269316303586&_rdoc=1&_issn=03702693&md5=afabd775fa7380dd028f231d672a093d" title="Click to view the MathML source">v4 pan>pan class="mathContainer hidden">pan class="mathCode"><math altimg="si4.gif" overflow="scroll"><msub><mrow><mi mathvariant="normal">vmi>mrow><mrow><mn>4mn>mrow>msub>math> pan> pan> pan>) anisotropic azimuthal flow over a wide range of pseudorapidities (pan id="mmlsi5" class="mathmlsrc">pan class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316303586&_mathId=si5.gif&_user=111111111&_pii=S0370269316303586&_rdoc=1&_issn=03702693&md5=8a85b44dae8fb199e19945be549092d8" title="Click to view the MathML source">−3.5<η<5 pan>pan class="mathContainer hidden">pan class="mathCode"><math altimg="si5.gif" overflow="scroll"><mo>−mo><mn>3.5mn><mo><mo><mi>ηmi><mo><mo><mn>5mn>math> pan> pan> pan>). The measurements are performed with Pb–Pb collisions at pan id="mmlsi1" class="mathmlsrc">mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316303586&_mathId=si1.gif&_user=111111111&_pii=S0370269316303586&_rdoc=1&_issn=03702693&md5=d8ce3f723832d73f2f75919ffd39233c">mg class="imgLazyJSB inlineImage" height="15" width="105" alt="View the MathML source" style="margin-top: -5px; vertical-align: middle" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0370269316303586-si1.gif">pt>mg height="15" border="0" style="vertical-align:bottom" width="105" alt="View the MathML source" title="View the MathML source" src="http://origin-ars.els-cdn.com/content/image/1-s2.0-S0370269316303586-si1.gif"> pt> pan class="mathContainer hidden">pan class="mathCode"><math altimg="si1.gif" overflow="scroll"><msqrt><msub><mrow><mi>smi>mrow><mrow><mi mathvariant="normal">NNmi>mrow>msub>msqrt><mo>=mo><mn>2.76mn><mtext> TeVmtext>math> pan> pan> pan> using the ALICE detector at the Large Hadron Collider (LHC). The flow harmonics are obtained using two- and four-particle correlations from nine different centrality intervals covering central to peripheral collisions. We find that the shape of pan id="mmlsi6" class="mathmlsrc">pan class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316303586&_mathId=si6.gif&_user=111111111&_pii=S0370269316303586&_rdoc=1&_issn=03702693&md5=75251f1f46549c175e779ff2b4ae8a8d" title="Click to view the MathML source">vn(η) pan>pan class="mathContainer hidden">pan class="mathCode"><math altimg="si6.gif" overflow="scroll"><msub><mrow><mi mathvariant="normal">vmi>mrow><mrow><mi>nmi>mrow>msub><mo stretchy="false">(mo><mi>ηmi><mo stretchy="false">)mo>math> pan> pan> pan> is largely independent of centrality for the flow harmonics pan id="mmlsi7" class="mathmlsrc">pan class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316303586&_mathId=si7.gif&_user=111111111&_pii=S0370269316303586&_rdoc=1&_issn=03702693&md5=ea9a291dd8beedf88a13c9103c79334a" title="Click to view the MathML source">n=2–4 pan>pan class="mathContainer hidden">pan class="mathCode"><math altimg="si7.gif" overflow="scroll"><mi>nmi><mo>=mo><mn>2mn><mtext>–mtext><mn>4mn>math> pan> pan> pan>, however the higher harmonics fall off more steeply with increasing pan id="mmlsi8" class="mathmlsrc">pan class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316303586&_mathId=si8.gif&_user=111111111&_pii=S0370269316303586&_rdoc=1&_issn=03702693&md5=8f072ec63cf8a21187020234d0a227ae" title="Click to view the MathML source">|η| pan>pan class="mathContainer hidden">pan class="mathCode"><math altimg="si8.gif" overflow="scroll"><mo stretchy="false">|mo><mi>ηmi><mo stretchy="false">|mo>math> pan> pan> pan>. We assess the validity of extended longitudinal scaling of pan id="mmlsi2" class="mathmlsrc">pan class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316303586&_mathId=si2.gif&_user=111111111&_pii=S0370269316303586&_rdoc=1&_issn=03702693&md5=9ca06101309bad52b1ff201bcbd21958" title="Click to view the MathML source">v2 pan>pan class="mathContainer hidden">pan class="mathCode"><math altimg="si2.gif" overflow="scroll"><msub><mrow><mi mathvariant="normal">vmi>mrow><mrow><mn>2mn>mrow>msub>math> pan> pan> pan> by comparing to lower energy measurements, and find that the higher harmonic flow coefficients are proportional to the charged particle densities at larger pseudorapidities. Finally, we compare our measurements to both hydrodynamical and transport models, and find they both have challenges when it comes to describing our data.