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Kopp, Gillian Baron; Tully, Christopher; Chung, Wonyong Paul; Kennedy, Kiley Elizabeth; Hoienko, Svitlana; Mans, Jeremiah Michael; Krohn, Michael David; Crossman, Bryan James; Hiltbrand, Joshua; Skuja, Andris; Wang, Long" /> <meta name="keywords" content="HCAL, Trigger" /> <script type="text/javascript" src="https://cds.cern.ch/js/jquery.min.js"></script>  <link rel="stylesheet" href="https://cds.cern.ch/img/webnews.css" type="text/css" />  <script type="text/javascript" src="https://cds.cern.ch/js/webnews.js?v=20131009"></script> <meta property="fb:app_id" content="137353533001720"/> <script type="text/x-mathjax-config"> MathJax.Hub.Config({ tex2jax: {inlineMath: [['$','$']], processEscapes: true}, showProcessingMessages: false, messageStyle: "none" }); </script> <script src="/MathJax/MathJax.js?config=TeX-AMS_CHTML" type="text/javascript"> </script>  <meta content="Design of a Level-1 Long-Lived Particle Trigger in the CMS Hadron Calorimeter" name="citation_title" /> <meta content="Kopp, Gillian Baron" name="citation_author" /> <meta content="Wang, Long" name="citation_author" /> <meta content="Tully, Christopher" name="citation_author" /> <meta content="Chung, Wonyong Paul" name="citation_author" /> <meta content="Mans, Jeremiah Michael" name="citation_author" /> <meta content="Kennedy, Kiley Elizabeth" name="citation_author" /> <meta content="Hoienko, Svitlana" name="citation_author" /> <meta content="Crossman, Bryan James" name="citation_author" /> <meta content="Krohn, Michael David" name="citation_author" /> <meta content="Skuja, Andris" name="citation_author" /> <meta content="Hiltbrand, Joshua" name="citation_author" /> <meta content="10.22323/1.478.0270" name="citation_doi" /> <meta content="PoS" name="citation_journal_title" /> <meta content="LHCP2024" name="citation_volume" /> <meta content="270" name="citation_firstpage" /> <meta content="2024/10/15" name="citation_publication_date" /> <meta name="citation_online_date" content="2024/11/08"> <meta content="CMS-CR-2024-257" name="citation_technical_report_number" /> <meta content="10.22323/1.478.0270" name="citation_doi" /> <meta name="citation_pdf_url" content="https://cds.cern.ch/record/2916518/files/CR2024_257.pdf" />  <meta content="Design of a Level-1 Long-Lived Particle Trigger in the CMS Hadron Calorimeter" property="og:title" /> <meta content="website" property="og:type" /> <meta content="website" property="og:type" /> <meta content="website" property="og:type" /> <meta content="https://cds.cern.ch/record/2916518" property="og:url" /> <meta content="CERN Document Server" property="og:site_name" /> <meta content="The Hadron Calorimeter (HCAL) in the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) was recently upgraded for Run 3 to introduce depth segmentation and online timing measurements, expanding the physics capabilities. In particular, the augmentation of the calorimeter information at the hardware trigger level enables quick identification and recording of long-lived particle decays using lower thresholds on energy-based event quantities. The depth segmentation and online timing capabilities are utilized in novel HCAL-based hardware-level triggers to identify displaced and delayed long-lived particles (LLPs), either decaying inside the calorimeter volume or arriving at a delayed time. This increases the sensitivity to LLP decays occurring up to almost 6 m from the collision point. This two-pronged calorimeter trigger approach leverages the new capabilities of the CMS HCAL to expand the phase space accessible in ongoing LLP searches. These triggers were deployed for Run 3 of the LHC, beginning data-taking in 2022, and we review the trigger implementation and calibration." property="og:description" />  <meta content="summary" name="twitter:card" /> <meta content="summary" name="twitter:card" /> <meta content="summary" name="twitter:card" /> <style></style> </head> <body class="CMS32Preprints search" lang="en">  <div id="cern-toolbar"> <h1><a href="http://cern.ch" title="CERN">CERN <span>Accelerating science</span></a></h1> <ul> <li class="cern-accountlinks"><a class="cern-account" href="https://cds.cern.ch/youraccount/login?ln=en&referer=https%3A//cds.cern.ch/record/2916518" title="Sign in to your CERN account">Sign in</a></li> <li><a class="cern-directory" href="http://cern.ch/directory" title="Search CERN resources and browse the directory">Directory</a></li> </ul> </div>   <div role="banner" class="clearfix" id="header"> <div class="header-inner inner"> <hgroup class="clearfix"> <h2 id="site-name"> <a rel="home" title="Home" href="/"><span>CERN Document Server</span></a> </h2> <h3 id="site-slogan">Access articles, reports and multimedia content in HEP</h3> </hgroup> <div role="navigation" id="main-navigation" class="cdsmenu"> <h2 class="element-invisible">Main menu</h2><ul class="links inline clearfix"> <li class="menu-386 first active-trail"><a class="active-trail" href="https://cds.cern.ch/?ln=en">Search</a></li> <li class="menu-444 "><a class="" title="" href="https://cds.cern.ch/submit?ln=en">Submit</a></li> <li class="menu-426 "><a class="" href="https://cds.cern.ch/help/?ln=en">Help</a></li> <li class="leaf hassubcdsmenu"> <a hreflang="en" class="header" href="https://cds.cern.ch/youraccount/display?ln=en">Personalize</a> <ul class="subsubcdsmenu"><li><a href="https://cds.cern.ch/youralerts/list?ln=en">Your alerts</a></li><li><a href="https://cds.cern.ch/yourbaskets/display?ln=en">Your baskets</a></li><li><a href="https://cds.cern.ch/yourcomments?ln=en">Your comments</a></li><li><a href="https://cds.cern.ch/youralerts/display?ln=en">Your searches</a></li></ul></li> </ul> </div> </div> </div>  <table class="navtrailbox"> <tr> <td class="navtrailboxbody"> <a href="/?ln=en" class="navtrail">Home</a> > <a href="/collection/CMS%20Collection?ln=en" class="navtrail">CMS Collection</a> > <a href="/collection/CMS%20Preprints?ln=en" class="navtrail">CMS Preprints</a> > Design of a Level-1 Long-Lived Particle Trigger in the CMS Hadron Calorimeter </td> </tr> </table> </div> <div class="pagebody"><div class="pagebodystripemiddle"> <div class="detailedrecordbox"> <div class="detailedrecordtabs"> <div> <ul class="detailedrecordtabs"><li class="on first"><a href="/record/2916518/?ln=en">Information </a></li><li class=""><a href="/record/2916518/references?ln=en">References </a></li><li class=""><a href="/record/2916518/comments?ln=en">Discussion (0) </a></li><li class=""><a href="/record/2916518/files?ln=en">Files </a></li></ul> <div id="tabsSpacer" style="clear:both;height:0px"> </div></div> </div> <div class="detailedrecordboxcontent"> <div class="top-left-folded"></div> <div class="top-right-folded"></div> <div class="inside">  <abbr class="unapi-id" title="2916518"></abbr>  <link href="/img/download_and_embed_buttons.css" rel="stylesheet" type="text/css" /> <style type="text/css">  .video_talk_wrapper{ max-width: 640px; min-height: 360px; } </style> <table class="formatRecordTableFullWidth"> <tr> <td class="formatRecordHeader" style="background-image: url('/img/journals.jpg');" colspan="2">  CMS Note </td> </tr> <tr><td class="formatRecordLabel"> Report number </td><td style="padding-left:5px;">CMS-CR-2024-257</td></tr> <tr><td class="formatRecordLabel"> Title </td><td style="padding-left:5px;"><b>Design of a Level-1 Long-Lived Particle Trigger in the CMS Hadron Calorimeter</b></td></tr> <style> .video_control_container, #video_controlbutton { display: none; }#video_detailbox_download {display: none;}#video_detailbox_embed {display: none;}</style> <div class="video_control_container"> <div style="box-sizing: inherit;position: relative;min-height: 1em;margin: 1em 0;background: #f8f8f9;padding: 1em 1.5em;line-height: 1.4285em;transition: opacity .1s ease,color .1s ease,background .1s ease,box-shadow .1s ease,-webkit-box-shadow .1s ease;border-radius: .28571429rem;font-size: 1.1em;margin-top: 0;margin-bottom: 6px;background-color: #f8ffff;color: #276f86;box-shadow: 0 0 0 1px #a9d5de inset,0 0 0 0 transparent;"> <i class="fa fa-info"></i><span style="padding-left: 9px;">If you experience any problem watching the video, click the download button below</span> </div> <a id="video_controlbutton_download" rel="download_button" class="video_controlbutton" href="#">Download</a> <a id="video_controlbutton_embed" class="video_controlbutton" href="#">Embed</a> </div> <div id="video_detailbox_download" style="margin:10px"> </div> <div id="video_detailbox_embed" style="margin:10px"> </div> <tr><td class="formatRecordLabel"> <span style="white-space:nowrap;">Author(s)</span> </td><td style="padding-left:5px;"> <script type="text/javascript"> function toggle_authors_visibility(){ var more = document.getElementById('more'); var link = document.getElementById('link'); var extension = document.getElementById('extension'); if (more.style.display=='none'){ more.style.display = ''; extension.style.display = 'none'; link.innerHTML = "Hide" } else { more.style.display = 'none'; extension.style.display = ''; link.innerHTML = "Show all 11 authors" } link.style.color = "rgb(204,0,0);" } function set_up(){ var extension = document.getElementById('extension'); extension.innerHTML = ""; toggle_authors_visibility(); } </script> <a name="show_hide" /><a href="https://cds.cern.ch/search?f=author&p=Kopp%2C%20Gillian%20Baron&ln=en">Kopp, Gillian Baron</a> (Princeton U.) ; <a href="https://cds.cern.ch/search?f=author&p=Tully%2C%20Christopher&ln=en">Tully, Christopher</a> (Princeton U.) ; <a href="https://cds.cern.ch/search?f=author&p=Chung%2C%20Wonyong%20Paul&ln=en">Chung, Wonyong Paul</a> (Princeton U.) ; <a href="https://cds.cern.ch/search?f=author&p=Kennedy%2C%20Kiley%20Elizabeth&ln=en">Kennedy, Kiley Elizabeth</a> (Princeton U.) ; <a href="https://cds.cern.ch/search?f=author&p=Hoienko%2C%20Svitlana&ln=en">Hoienko, Svitlana</a> (Princeton U.) ; <a href="https://cds.cern.ch/search?f=author&p=Mans%2C%20Jeremiah%20Michael&ln=en">Mans, Jeremiah Michael</a> (Minnesota U.) ; <a href="https://cds.cern.ch/search?f=author&p=Krohn%2C%20Michael%20David&ln=en">Krohn, Michael David</a> (Minnesota U.) ; <a href="https://cds.cern.ch/search?f=author&p=Crossman%2C%20Bryan%20James&ln=en">Crossman, Bryan James</a> (Minnesota U.) ; <a href="https://cds.cern.ch/search?f=author&p=Hiltbrand%2C%20Joshua&ln=en">Hiltbrand, Joshua</a> (Baylor U.) ; <a href="https://cds.cern.ch/search?f=author&p=Skuja%2C%20Andris&ln=en">Skuja, Andris</a> (Maryland U.)<span id="more" style=""> ; <a href="https://cds.cern.ch/search?f=author&p=Wang%2C%20Long&ln=en">Wang, Long</a> (Maryland U.)</span> <span id="extension"></span> <small><i><a id="link" href="#" onclick="toggle_authors_visibility()" style="color:rgb(204,0,0);"></a></i></small><script type="text/javascript">set_up()</script></td></tr> <tr><td class="formatRecordLabel"> Publication </td><td style="padding-left:5px;">2025</td></tr>  <script type="text/javascript"> /* * Changes the Imprint title to Date - Duration as requested by RQF0820114 * This is a hack not to touch the general imprint format element */ $(document).ready(function() { var collections = 'INTNOTECMSPUBL ; ConferencePaper ; ARTICLE'; if (collections.indexOf('E-LEARNING') > -1) { $('.cern-imprint-label').text('Date - Duration'); } }) </script> <tr><td class="formatRecordLabel cern-imprint-label"> Imprint </td><td style="padding-left:5px;">15 Oct 2024</td></tr> <tr><td class="formatRecordLabel"> Number of pages </td><td style="padding-left:5px;">5</td></tr>  <tr><td class="formatRecordLabel"> Published in: </td><td style="padding-left:5px;"><a href="http://dx.doi.org/10.22323/1.478.0270"><i>PoS</i> LHCP2024 (2025) 270</a> </a></td></tr> <tr><td class="formatRecordLabel"> Presented at </td><td style="padding-left:5px;"><a href="https://cds.cern.ch/record/2897247">12th Edition of the Large Hadron Collider Physics Conference (LHCP2024)</a>, Boston, United States, 3 - 7 Jun 2024, pp.270</td></tr> <tr><td class="formatRecordLabel"> DOI </td><td style="padding-left:5px;"><a href="http://dx.doi.org/10.22323/1.478.0270" title="DOI" target="_blank">10.22323/1.478.0270</a> <tr><td class="formatRecordLabel"> Subject category </td><td style="padding-left:5px;">Detectors and Experimental Techniques</td></tr> <tr><td class="formatRecordLabel"> Accelerator/Facility, Experiment </td><td style="padding-left:5px;"><a href="https://cds.cern.ch/search?p=CERN%20LHC&f=693__a">CERN LHC</a> ; <a href="https://cds.cern.ch/search?p=CMS&f=693__e">CMS</a></td></tr> <tr><td class="formatRecordLabel"> Keywords </td><td style="padding-left:5px;"><a href="https://cds.cern.ch/search?f=keyword&p=HCAL&ln=en">HCAL</a> ; <a href="https://cds.cern.ch/search?f=keyword&p=Trigger&ln=en">Trigger</a></td></tr> <tr><td class="formatRecordLabel"> Abstract </td><td style="padding-left:5px;">The Hadron Calorimeter (HCAL) in the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) was recently upgraded for Run 3 to introduce depth segmentation and online timing measurements, expanding the physics capabilities. In particular, the augmentation of the calorimeter information at the hardware trigger level enables quick identification and recording of long-lived particle decays using lower thresholds on energy-based event quantities. The depth segmentation and online timing capabilities are utilized in novel HCAL-based hardware-level triggers to identify displaced and delayed long-lived particles (LLPs), either decaying inside the calorimeter volume or arriving at a delayed time. This increases the sensitivity to LLP decays occurring up to almost 6 m from the collision point. This two-pronged calorimeter trigger approach leverages the new capabilities of the CMS HCAL to expand the phase space accessible in ongoing LLP searches. These triggers were deployed for Run 3 of the LHC, beginning data-taking in 2022, and we review the trigger implementation and calibration.</td></tr> <tr><td class="formatRecordLabel"> Other source </td><td style="padding-left:5px;"><a href="http://inspirehep.net/record/2866429">Inspire</a></td></tr> </table> <br/><div><div style="clear: both;"> </div></div> <script type="text/javascript"> // Initially hide: $(".longCaption").hide(); // Allow to toggle visibility: $(".toggleLongCaption").toggle(function(){ $(this).siblings(".longCaption").show('fast'); var thisElem = $(this); thisElem.text(thisElem.text() === "more" ? "less" : "more"); },function(){ $(this).siblings(".longCaption").hide('fast'); var thisElem = $(this); thisElem.text(thisElem.text() === "more" ? 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In particular, the augmentation of the calorimeter information at the hardware trigger level enables quick identification and recording of long-lived particle decays using lower thresholds on energy-based event quantities. The depth segmentation and online timing capabilities are utilized in novel HCAL-based hardware-level triggers to identify displaced and delayed long-lived particles (LLPs), either decaying inside the calorimeter volume or arriving at a delayed time. This increases the sensitivity to LLP decays occurring up to almost 6 m from the collision point. This two-pronged calorimeter trigger approach leverages the new capabilities of the CMS HCAL to expand the phase space accessible in ongoing LLP searches. These triggers were deployed for Run 3 of the LHC, beginning data-taking in 2022, and we review the trigger implementation and calibration." }); // ]]> </script>  </div> </div> <div style="clear:both;margin-bottom: 0;"></div> </div> <div class="bottom-left"></div><div class="bottom-right"></div> </div> </div></div> <footer id="footer" class="pagefooter clearfix">  <div class="pagefooterstripeleft"> CERN Document Server :: <a class="footer" href="https://cds.cern.ch/?ln=en">Search</a> :: <a class="footer" href="https://cds.cern.ch/submit?ln=en">Submit</a> :: <a class="footer" href="https://cds.cern.ch/youraccount/display?ln=en">Personalize</a> :: <a class="footer" href="https://cds.cern.ch/help/?ln=en">Help</a> :: <a class="footer" href="https://cern.service-now.com/service-portal?id=privacy_policy&se=CDS-Service" target="_blank">Privacy Notice</a> :: <a class="footer" href="https://repository.cern/content-policy" target="_blank">Content Policy</a> :: <a class="footer" href="https://repository.cern/terms" target="_blank">Terms and Conditions</a> <br /> Powered by <a class="footer" href="http://invenio-software.org/">Invenio</a> <br /> Maintained by <a class="footer" href="https://cern.service-now.com/service-portal?id=service_element&name=CDS-Service">CDS Service</a> - Need help? 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