{"id":28626,"date":"2025-09-23T09:17:06","date_gmt":"2025-09-23T03:32:06","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=28626"},"modified":"2025-09-23T09:17:32","modified_gmt":"2025-09-23T03:32:32","slug":"shape-shifting-collisions-probe-secrets-of-early-universe","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/shape-shifting-collisions-probe-secrets-of-early-universe\/","title":{"rendered":"Shape-shifting collisions probe secrets of early Universe\u00a0"},"content":{"rendered":"\n

The first high-energy collisions between light nuclei at the Large Hadron Collider confirm the unusual \u201cbowling-pin\u201d shape of neon nuclei and offer up a new tool to study the extreme state of matter produced in the aftermath of the Big Bang\u00a0<\/strong><\/em><\/p>\n\n\n\n

\"\"
Artistic rendering of quark\u2013gluon plasma (Image: CERN)<\/sup><\/em><\/figcaption><\/figure>\n\n\n\n

This summer, the\u00a0Large Hadron Collider<\/a>\u00a0(LHC) took a breath of fresh air. Normally filled with beams of protons, the 27-km ring was reconfigured to enable its\u00a0first oxygen\u2013oxygen and neon\u2013neon collisions.\u00a0<\/p>\n\n\n\n

First results from the new data, recorded over a period of six days by the\u00a0ALICE<\/a>,\u00a0ATLAS<\/a>,\u00a0CMS<\/a>\u00a0and\u00a0LHCb<\/a>\u00a0experiments, were presented during the\u00a0Initial Stages conference<\/a>\u00a0held\u00a0in Taipei, Taiwan, on 7\u201312 September.
\u00a0
Smashing atomic nuclei into one another allows physicists to study the\u00a0quark\u2013gluon plasma<\/a>\u00a0(QGP), an extreme state of matter that mimics the conditions of the Universe during its first microseconds, before atoms formed. Until now, exploration of this\u00a0hot and dense state of free particles at the LHC relied on collisions between heavy ions (like lead or xenon), which maximise the size of the plasma droplet created.<\/p>\n\n\n\n

Collisions between lighter ions, such as oxygen, open a new window on the QGP to better understand its characteristics and evolution. Not only are they smaller than lead or xenon, allowing a better investigation of the minimum size of nuclei needed to create the QGP, but they are less regular in shape. A neon nucleus, for example, is predicted to be elongated like a bowling pin \u2013 a picture that has now been brought into sharper focus thanks to the new LHC results. <\/p>\n\n\n\n

The experiments focused on measurements of subtle patterns in the angles and directions of the particles flying outward as the QGP droplet expands and cools, which are caused by small distortions in the original collision zone.\u00a0<\/p>\n\n\n\n

Remarkably, these \u201cflow\u201d patterns can be described using the same fluid-dynamics calculations that are used to model everyday fluids, allowing\u00a0researchers to probe both the properties of the QGP and the geometry of the colliding nuclei.\u00a0Accurate model predictions enable a more precise exploration of flow in oxygen\u2013oxygen and neon\u2013neon collisions than in proton\u2013proton and proton\u2013lead collisions.<\/p>\n\n\n\n

ALICE, which specialises in the study of the QGP, as well as the general-purpose experiments ATLAS and CMS, have measured sizeable\u00a0elliptic and triangular\u00a0flow\u00a0in oxygen\u2013oxygen and neon\u2013neon collisions, and found that these depend strongly on whether the collisions are glancing or head-on. <\/p>\n\n\n\n

The level of agreement between theory and data is comparable to that obtained for collisions of heavier xenon and lead ions, despite the much smaller system size.\u00a0This provides\u00a0strong evidence that flow in oxygen\u2013oxygen and neon\u2013neon collisions is driven by nuclear geometry, supporting the bowling-pin structure of the neon nucleus and demonstrating that hydrodynamic flow emerges robustly across collision systems at the LHC.<\/p>\n\n\n\n

Complementary results presented last week by the LHCb collaboration confirm the bowling-pin shape of the neon nucleus. The results are based on lead\u2013argon and lead\u2013neon collisions in a fixed-target configuration, using data recorded in 2024 with its SMOG<\/a> apparatus. The LHCb collaboration has also started to analyse the oxygen\u2013oxygen and neon\u2013neon collision data.<\/p>\n\n\n\n

\u201cTaken together, these results bring fresh perspectives on nuclear structure and how matter emerged after the Big Bang,\u201d says CERN Director for Research and Computing Joachim Mnich.<\/p>\n","protected":false},"excerpt":{"rendered":"

This summer, the\u00a0Large Hadron Collider\u00a0(LHC) took a breath of fresh air. Normally filled with beams of protons, the 27-km ring was reconfigured to enable its\u00a0first oxygen\u2013oxygen and neon\u2013neon collisions.\u00a0<\/p>\n","protected":false},"author":2,"featured_media":28627,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[121,17],"tags":[],"class_list":["post-28626","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-physics","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions.webp",1920,1080,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-200x200.webp",200,200,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-675x380.webp",675,380,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-768x432.webp",750,422,true],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-1100x619.webp",750,422,true],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-1536x864.webp",1536,864,true],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions.webp",1920,1080,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-1200x800.webp",1200,800,true],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-870x570.webp",870,570,true],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-600x900.webp",600,900,true],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-600x600.webp",600,600,true],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-760x490.webp",760,490,true],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-550x360.webp",550,360,true],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-95x65.webp",95,65,true],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-640x853.webp",640,853,true],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-96x96.webp",96,96,true],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/09\/shape-shifting-collisions-150x84.webp",150,84,true]},"author_info":{"info":["RevoScience"]},"category_info":"Physics<\/a> Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/28626","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=28626"}],"version-history":[{"count":1,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/28626\/revisions"}],"predecessor-version":[{"id":28628,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/28626\/revisions\/28628"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/28627"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=28626"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=28626"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=28626"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}