{"title":"Σ Hyperons Production in pp and p-Pb Collisions at LHC with ALICE","authors":"A. Borisov","doi":"10.1134/s1063779624700710","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In addition to <span>\\(\\Lambda \\)</span> hyperons, new data on <span>\\(\\Sigma \\)</span> hyperons production are compared to different Monte-Carlo models and contribute to understand hadron production mechanisms. The first measurements of the transverse momentum (<span>\\({{p}_{{\\text{T}}}}\\)</span>) spectra of <span>\\({{\\Sigma }^{0}}\\)</span> and <span>\\({{\\overline \\Sigma }^{0}}\\)</span> hyperons in pp collisions at <span>\\(\\sqrt s = 7\\)</span> TeV at the LHC are presented. The <span>\\({{\\Sigma }^{0}}\\)</span>(<span>\\({{\\overline \\Sigma }^{0}}\\)</span>) is reconstructed via its electromagnetic decay channel <span>\\(\\Lambda (\\overline \\Lambda ) + \\gamma \\)</span>, while the <span>\\(\\Lambda \\)</span>(<span>\\(\\overline \\Lambda \\)</span>) baryon is detected via its decay into <span>\\(p + {{\\pi }^{ - }}\\)</span> (<span>\\(\\bar {p}\\)</span> + <span>\\({{\\pi }^{ + }}\\)</span>). The low-energy photon is measured via conversion into <span>\\({{e}^{ + }}{{e}^{ - }}\\)</span> pairs in the detector material and in PHOS calorimeter by exploiting the unique capability of the ALICE detector. The complementary results on the first detection of <span>\\({{\\Sigma }^{ + }}\\)</span> and <span>\\({{\\overline \\Sigma }^{ - }}\\)</span> hyperon at the LHC with ALICE are shown in pp collisions at <span>\\(\\sqrt s = 13\\)</span> TeV. The <span>\\({{\\Sigma }^{ + }}\\)</span>(<span>\\({{\\overline \\Sigma }^{ - }}\\)</span>) is reconstructed via its weak decay into <i>p</i><span>\\((\\bar {p}) + {{\\pi }^{0}}\\)</span> with the challenging detection of low-energy photons from <span>\\({{\\pi }^{0}}\\)</span> decay. Also, the first reconstruction of <span>\\({{\\overline \\Sigma }^{ \\pm }} \\to \\bar {n} + {{\\pi }^{ \\pm }}\\)</span> decays and <span>\\({{\\overline \\Sigma }^{ \\pm }}\\)</span> transverse momenta spectra in pp and <i>p</i>-Pb collisions are presented. Antineutron is identified and reconstructed with PHOS by unique signature of the annihilation process.</p>","PeriodicalId":729,"journal":{"name":"Physics of Particles and Nuclei","volume":"59 1","pages":""},"PeriodicalIF":0.6000,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics of Particles and Nuclei","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1134/s1063779624700710","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"PHYSICS, PARTICLES & FIELDS","Score":null,"Total":0}
引用次数: 0
Abstract
In addition to \(\Lambda \) hyperons, new data on \(\Sigma \) hyperons production are compared to different Monte-Carlo models and contribute to understand hadron production mechanisms. The first measurements of the transverse momentum (\({{p}_{{\text{T}}}}\)) spectra of \({{\Sigma }^{0}}\) and \({{\overline \Sigma }^{0}}\) hyperons in pp collisions at \(\sqrt s = 7\) TeV at the LHC are presented. The \({{\Sigma }^{0}}\)(\({{\overline \Sigma }^{0}}\)) is reconstructed via its electromagnetic decay channel \(\Lambda (\overline \Lambda ) + \gamma \), while the \(\Lambda \)(\(\overline \Lambda \)) baryon is detected via its decay into \(p + {{\pi }^{ - }}\) (\(\bar {p}\) + \({{\pi }^{ + }}\)). The low-energy photon is measured via conversion into \({{e}^{ + }}{{e}^{ - }}\) pairs in the detector material and in PHOS calorimeter by exploiting the unique capability of the ALICE detector. The complementary results on the first detection of \({{\Sigma }^{ + }}\) and \({{\overline \Sigma }^{ - }}\) hyperon at the LHC with ALICE are shown in pp collisions at \(\sqrt s = 13\) TeV. The \({{\Sigma }^{ + }}\)(\({{\overline \Sigma }^{ - }}\)) is reconstructed via its weak decay into p\((\bar {p}) + {{\pi }^{0}}\) with the challenging detection of low-energy photons from \({{\pi }^{0}}\) decay. Also, the first reconstruction of \({{\overline \Sigma }^{ \pm }} \to \bar {n} + {{\pi }^{ \pm }}\) decays and \({{\overline \Sigma }^{ \pm }}\) transverse momenta spectra in pp and p-Pb collisions are presented. Antineutron is identified and reconstructed with PHOS by unique signature of the annihilation process.
期刊介绍:
The journal Fizika Elementarnykh Chastits i Atomnogo Yadr of the Joint Institute for Nuclear Research (JINR, Dubna) was founded by Academician N.N. Bogolyubov in August 1969. The Editors-in-chief of the journal were Academician N.N. Bogolyubov (1970–1992) and Academician A.M. Baldin (1992–2001). Its English translation, Physics of Particles and Nuclei, appears simultaneously with the original Russian-language edition. Published by leading physicists from the JINR member states, as well as by scientists from other countries, review articles in this journal examine problems of elementary particle physics, nuclear physics, condensed matter physics, experimental data processing, accelerators and related instrumentation ecology and radiology.