Cosmic-ray searches with the MATHUSLA detector

The performance of the proposed MATHUSLA detector as an instrument for studying the physics of cosmic rays by measuring extensive air showers is presented. The MATHUSLA detector is designed to observe and study the decay of long-lived particles produced at the pp interaction point of the CMS detector at CERN during the HL-LHC data-taking period. The proposed MATHUSLA detector will be composed of many layers of long scintillating bars that cannot measure more than one hit per bar and correctly report the hit coordinate in case of multiple hits. This study shows that adding a layer of RPC detectors with both analogue and digital readout significantly enhances the capabilities of MATHUSLA to measure the local densities and arrival times of charged particles at the front of air showers. We discuss open issues in cosmic-ray physics that the proposed MATHUSLA detector with an additional layer of RPC detectors could address and conclude by comparing with other air-shower facilities that measure cosmic rays in the PeV energy range.Comment: 64 pages, 58 figure

Recent Progress and Next Steps for the MATHUSLA LLP Detector

We report on recent progress and next steps in the design of the proposed MATHUSLA Long Lived Particle (LLP) detector for the HL-LHC as part of the Snowmass 2021 process. Our understanding of backgrounds has greatly improved, aided by detailed simulation studies, and significant R&D has been performed on designing the scintillator detectors and understanding their performance. The collaboration is on track to complete a Technical Design Report, and there are many opportunities for interested new members to contribute towards the goal of designing and constructing MATHUSLA in time for HL-LHC collisions, which would increase the sensitivity to a large variety of highly motivated LLP signals by orders of magnitude.Comment: Contribution to Snowmass 2021 (EF09, EF10, IF6, IF9), 18 pages, 12 figures. v2: included additional endorser

Detección de muones atmosféricos en el experimento ALICE-LHC

The calibration, alignment and commissioning of most of the ALICE (A Large Ion Collider Experiment at the CERN LHC) detectors have required a large amount of cosmic events during 2010, 2011, 2012 and 2013. Two main triggers were implemented to collect the atmospheric muons crossing the experiment. The first trigger, called “ACORDE trigger”, is generated by 60 scintillators located on the top three sides of the L3 magnet surrounding the central detectors, and selects single muons and bundles of atmospheric muons. The second trigger, called “TOF trigger”, is obtained by requiring a simultaneous signal on some pads of the Time of Flight (TOF) detector. The analysis of multi-muon events triggered by ACORDE and TOF and reconstructed using the ALICE Time Projection Chamber (TPC) is presented. A special emphasis in the study of muon bundles, with a particular attention on high muon density events is discussed. In particular the muon multiplicity distribution, that gives information on the primary cosmic ray composition in the energy range around the knee, has shown some unexpected events of very high multiplicity

Explore the lifetime frontier with MATHUSLA

The observation of long-lived particles at the LHC would reveal physics beyond the Standard Model, could account for the many open issues in our understanding of our universe, and conceivably point to a more complete theory of the fundamental interactions. Such long-lived particle signatures are fundamentally motivated and can appear in virtually every theoretical construct that address the Hierarchy Problem, Dark Matter, Neutrino Masses and the Baryon Asymmetry of the Universe. We describe in this document a large detector, MATHUSLA, located on the surface above an HL-LHC $pp$ interaction point, that could observe long-lived particles with lifetimes up to the Big Bang Nucleosynthesis limit of 0.1 s. We also note that its large detector area allows MATHUSLA to make important contributions to cosmic ray physics. Because of the potential for making a major breakthrough in our conceptual understanding of the universe, long-lived particle searches should have the highest level of priority.The observation of long-lived particles at the LHC would reveal physics beyond the Standard Model and could account for the many open issues in our understanding of our universe. Long-lived particle signatures are well motivated and can appear in many theoretical constructs that address the Hierarchy Problem, Dark Matter, Neutrino Masses and the Baryon Asymmetry of the Universe. With the current experiments at the particle accelerators, no search strategy will be able to observe the decay of neutral long-lived particles with masses above GeV and lifetimes at the limit set by Big Bang Nucleosynthesis, cτ ∼ 107–108 m. The MATHUSLA detector concept (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) will be presented. It can be implemented on the surface above ATLAS or CMS detectors in time for the high-luminosity LHC operations, to search for neutral long-lived particles with lifetimes up to the BBN limit. The large area of the detector allows MATHUSLA to make important contributions also to cosmic-ray physics. We will also report on the analysis of data collected by the test stand installed on the surface above the ATLAS detector, the on-going background studies, and plans for the MATHUSLA detector

A Letter of Intent for MATHUSLA: a dedicated displaced vertex detector above ATLAS or CMS.

In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) [1], a dedicated large-volume displaced vertex detector (DV) for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) without trigger limitations and with very low or zero backgrounds, allowing it to probe LLP cross sections and lifetimes up to several orders of magnitude beyond the reach of ATLAS or CMS. MATHUSLA would also act as a cutting-edge cosmic ray telescope at CERN, exploring many open questions in cosmic ray and astro-particle physics.In this Letter of Intent (LOI) we propose the construction of MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles), a dedicated large-volume displaced vertex detector for the HL-LHC on the surface above ATLAS or CMS. Such a detector, which can be built using existing technologies with a reasonable budget in time for the HL-LHC upgrade, could search for neutral long-lived particles (LLPs) with up to several orders of magnitude better sensitivity than ATLAS or CMS, while also acting as a cutting-edge cosmic ray telescope at CERN to explore many open questions in cosmic ray and astro-particle physics. We review the physics motivations for MATHUSLA and summarize its LLP reach for several different possible detector geometries, as well as outline the cosmic ray physics program. We present several updated background studies for MATHUSLA, which help inform a first detector-design concept utilizing modular construction with Resistive Plate Chambers (RPCs) as the primary tracking technology. We present first efficiency and reconstruction studies to verify the viability of this design concept, and we explore some aspects of its total cost. We end with a summary of recent progress made on the MATHUSLA test stand, a small-scale demonstrator experiment currently taking data at CERN Point 1, and finish with a short comment on future work

An Update to the Letter of Intent for MATHUSLA: Search for Long-Lived Particles at the HL-LHC

We report on recent progress in the design of the proposed MATHUSLA Long Lived Particle (LLP) detector for the HL-LHC, updating the information in the original Letter of Intent (LoI), see CDS:LHCC-I-031, arXiv:1811.00927. A suitable site has been identified at LHC Point 5 that is closer to the CMS Interaction Point (IP) than assumed in the LoI. The decay volume has been increased from 20 m to 25 m in height. Engineering studies have been made in order to locate much of the decay volume below ground, bringing the detector even closer to the IP. With these changes, a 100 m x 100 m detector has the same physics reach for large c$\tau$ as the 200 m x 200 m detector described in the LoI and other studies.The performance for small c$\tau$ is improved because of the proximity to the IP. Detector technology has also evolved while retaining the strip-like sensor geometry in Resistive Plate Chambers (RPC) described in the LoI. The present design uses extruded scintillator bars read out using wavelength shifting fibers and silicon photomultipliers (SiPM). Operations will be simpler and more robust with much lower operating voltages and without the use of greenhouse gases. Manufacturing is straightforward and should result in cost savings. Understanding of backgrounds has also significantly advanced, thanks to new simulation studies and measurements taken at the MATHUSLA test stand operating above ATLAS in 2018. We discuss next steps for the MATHUSLA collaboration, and identify areas where new members can make particularly important contributions.We report on recent progress in the design of the proposed MATHUSLA Long Lived Particle (LLP) detector for the HL-LHC, updating the information in the original Letter of Intent (LoI), see CDS:LHCC-I-031, arXiv:1811.00927. A suitable site has been identified at LHC Point 5 that is closer to the CMS Interaction Point (IP) than assumed in the LoI. The decay volume has been increased from 20 m to 25 m in height. Engineering studies have been made in order to locate much of the decay volume below ground, bringing the detector even closer to the IP. With these changes, a 100 m x 100 m detector has the same physics reach for large c$\tau$ as the 200 m x 200 m detector described in the LoI and other studies. The performance for small c$\tau$ is improved because of the proximity to the IP. Detector technology has also evolved while retaining the strip-like sensor geometry in Resistive Plate Chambers (RPC) described in the LoI. The present design uses extruded scintillator bars read out using wavelength shifting fibers and silicon photomultipliers (SiPM). Operations will be simpler and more robust with much lower operating voltages and without the use of greenhouse gases. Manufacturing is straightforward and should result in cost savings. Understanding of backgrounds has also significantly advanced, thanks to new simulation studies and measurements taken at the MATHUSLA test stand operating above ATLAS in 2018. We discuss next steps for the MATHUSLA collaboration, and identify areas where new members can make particularly important contributions