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An Update to the Letter of Intent for MATHUSLA: Search for Long-Lived Particles at the HL-LHC
Authors:
Cristiano Alpigiani,
Juan Carlos Arteaga-Velázquez,
Austin Ball,
Liron Barak,
Jared Barron,
Brian Batell,
James Beacham,
Yan Benhammo,
Karen Salomé Caballero-Mora,
Paolo Camarri,
Roberto Cardarelli,
John Paul Chou,
Wentao Cui,
David Curtin,
Miriam Diamond,
Keith R. Dienes,
Liam Andrew Dougherty,
Giuseppe Di Sciascio,
Marco Drewes,
Erez Etzion,
Rouven Essig,
Jared Evans,
Arturo Fernández Téllez,
Oliver Fischer,
Jim Freeman
, et al. (58 additional authors not shown)
Abstract:
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…
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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$τ$ as the 200 m x 200 m detector described in the LoI and other studies. The performance for small c$τ$ 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.
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Submitted 3 September, 2020;
originally announced September 2020.
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The MATHUSLA Test Stand
Authors:
Maf Alidra,
Cristiano Alpigiani,
Austin Ball,
Paolo Camarri,
Roberto Cardarelli,
John Paul Chou,
David Curtin,
Erez Etzion,
Ali Garabaglu,
Brandon Gomes,
Roberto Guida,
W. Kuykendall,
Audrey Kvam,
Dragoslav Lazic,
H. J. Lubatti,
Giovanni Marsella,
Gilad Mizrachi,
Antonio Policicchio,
Mason Proffitt,
Joe Rothberg,
Rinaldo Santonico,
Yiftah Silver,
Steffie Ann Thayil,
Emma Torro-Pastor,
Gordon Watts
, et al. (1 additional authors not shown)
Abstract:
The rate of muons from LHC $pp$ collisions reaching the surface above the ATLAS interaction point is measured and compared with expected rates from decays of $W$ and $Z$ bosons and $b$- and $c$-quark jets. In addition, data collected during periods without beams circulating in the LHC provide a measurement of the background from cosmic ray inelastic backscattering that is compared to simulation pr…
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The rate of muons from LHC $pp$ collisions reaching the surface above the ATLAS interaction point is measured and compared with expected rates from decays of $W$ and $Z$ bosons and $b$- and $c$-quark jets. In addition, data collected during periods without beams circulating in the LHC provide a measurement of the background from cosmic ray inelastic backscattering that is compared to simulation predictions. Data were recorded during 2018 in a 2.5 $\times$ 2.5 $\times$ 6.5~$\rm{m}^3$ active volume MATHUSLA test stand detector unit consisting of two scintillator planes, one at the top and one at the bottom, which defined the trigger, and six layers of RPCs between them, grouped into three $(x,y)$-measuring layers separated by 1.74 m from each other. Triggers selecting both upward-going tracks and downward-going tracks were used.
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Submitted 9 September, 2020; v1 submitted 5 May, 2020;
originally announced May 2020.
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Further studies on the physics potential of an experiment using LHC neutrinos
Authors:
N. Beni,
M. Brucoli,
V. Cafaro,
F. Cerutti,
G. M. Dallavalle,
S. Danzeca,
A. DeRoeck,
A. De Rujula,
D. Fasanella,
V. Giordano,
C. Guandalini,
A. Ioannisyan,
D. Lazic,
A. Margotti,
S. Lo Meo,
F. L. Navarria,
L. Patrizii,
T. Rovelli,
M. Sabate-Gilarte,
F. Sanchez Galan,
P. Santos Diaz,
G. Sirri,
Z. Szillasi,
C. -E. Wulz
Abstract:
We discuss an experiment to investigate neutrino physics at the LHC in Run 3, with emphasis on tau flavour. As described in our previous paper [arXiv:1903.06564v1], the detector can be installed in the decommissioned TI18 tunnel, about 480 m downstream the ATLAS cavern, after the first bending dipoles of the LHC arc. In that location, the prolongation of the beam Line-of-Sight from Interaction Poi…
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We discuss an experiment to investigate neutrino physics at the LHC in Run 3, with emphasis on tau flavour. As described in our previous paper [arXiv:1903.06564v1], the detector can be installed in the decommissioned TI18 tunnel, about 480 m downstream the ATLAS cavern, after the first bending dipoles of the LHC arc. In that location, the prolongation of the beam Line-of-Sight from Interaction Point IP1 to TI18 traverses about 100 m of rock. The detector intercepts the intense neutrino flux, generated by the LHC beams colliding in IP1, at large pseudorapidity eta, where neutrino energies can exceed a TeV. This paper focuses on optimizing global features of the experiment, like detector mass and acceptance. Since the neutrino-nucleon interaction cross section grows almost linearly with energy, the detector can be light and still collect a considerable sample of neutrino events; in the present study it weighs less than 3 tons. The detector is positioned off the beam axis, slightly above the ideal prolongation of the LHC beam from the straight section, covering 7.4 < eta < 9.2. In this configuration, the flux at high energies (0.5-1.5 TeV and beyond) is found to be dominated by neutrinos originating directly from IP1, mostly from charm decays, of which about 50% are electron neutrinos and about 5% are tau neutrinos. The contribution of pion and kaon decays to the muon neutrino flux is studied by means of simulations that embed the LHC optics and found small at high energies. The above studies indicate that with 150 /fb of delivered LHC luminosity in Run 3 the experiment can record a few thousand very high energy neutrino charged current interactions and over 50 tau neutrino charged current events.
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Submitted 16 April, 2020;
originally announced April 2020.
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XSEN: a $ν$N Cross Section Measurement using High Energy Neutrinos from pp collisions at the LHC
Authors:
N. Beni,
S. Buontempo,
T. Camporesi,
F. Cerutti,
G. M. Dallavalle,
G. De Lellis,
A. De Roeck,
A. De Rujula,
A. Di Crescenzo,
D. Fasanella,
A. Ioannisyan,
D. Lazic,
A. Margotti,
S. Lo Meo,
F. L. Navarria,
L. Patrizii,
T. Rovelli,
M. Sabate-Gilarte,
F. Sanchez Galan,
P. Santos Diaz,
G. Sirri,
Z. Szillasi,
C. Wulz
Abstract:
XSEN (Cross Section of Energetic Neutrinos) is a small experiment designed to study, for the first time, neutrino-nucleon interactions (including the tau flavour) in the 0.5-1 TeV neutrino energy range. The detector will be installed in the decommissioned TI18 tunnel and uses nuclear emulsions. Its simplicity allows construction and installation before the LHC Run 3, 2021-2023; with 150/fb in Run3…
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XSEN (Cross Section of Energetic Neutrinos) is a small experiment designed to study, for the first time, neutrino-nucleon interactions (including the tau flavour) in the 0.5-1 TeV neutrino energy range. The detector will be installed in the decommissioned TI18 tunnel and uses nuclear emulsions. Its simplicity allows construction and installation before the LHC Run 3, 2021-2023; with 150/fb in Run3, the experiment can record up to two thousand neutrino interactions, and up to a hundred tau neutrino events. The XSEN detector intercepts the intense neutrino flux, generated by the LHC beams colliding in IP1, at large pseudo-rapidities, where neutrino energies can exceed the TeV. Since the neutrino-N interaction cross section grows almost linearly with energy, the detector can be light and still collect a considerable sample of neutrino interactions. In our proposal, the detector weighs less than 3 tons. It is lying slightly above the ideal prolongation of the LHC beam from the straight section; this configuration, off the beam axis, although very close to it, enhances the contribution of neutrinos from c and b decays, and consequently of tau neutrinos. The detector fits in the TI18 tunnel without modifications. We plan for a demonstrator experiment in 2021 with a small detector of about 0.5 tons; with 25/fb, nearly a hundred interactions of neutrinos of about 1 TeV can be recorded. The aim of this pilot run is a good in-situ characterisation of the machine-generated backgrounds, an experimental verification of the systematic uncertainties and efficiencies, and a tuning of the emulsion analysis infrastructure and efficiency. This Letter provides an overview of the experiment motivations, location, design constraints, technology choice, and operation.
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Submitted 24 October, 2019;
originally announced October 2019.
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Physics Potential of an Experiment using LHC Neutrinos
Authors:
N. Beni,
M. Brucoli,
S. Buontempo,
V. Cafaro,
G . M. Dallavalle,
S. Danzeca,
G. De Lellis,
A. Di Crescenzo,
V. Giordano,
C. Guandalini,
D. Lazic,
S. Lo Meo,
F. L. Navarria,
Z. Szillasi
Abstract:
Production of neutrinos is abundant at LHC. Flavour composition and energy reach of the neutrino flux from proton-proton collisions depend on the pseudorapidity $η$. At large $η$, energies can exceed the TeV, with a sizeable contribution of the $τ$ flavour. A dedicated detector could intercept this intense neutrino flux in the forward direction, and measure the interaction cross section on nucleon…
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Production of neutrinos is abundant at LHC. Flavour composition and energy reach of the neutrino flux from proton-proton collisions depend on the pseudorapidity $η$. At large $η$, energies can exceed the TeV, with a sizeable contribution of the $τ$ flavour. A dedicated detector could intercept this intense neutrino flux in the forward direction, and measure the interaction cross section on nucleons in the unexplored energy range from a few hundred GeV to a few TeV. The high energies of neutrinos result in a larger $ν$N interaction cross section, and the detector size can be relatively small. Machine backgrounds vary rapidly while moving along and away from the beam line. Four locations were considered as hosts for a neutrino detector: the CMS quadruplet region (~25 m from CMS Interaction Point (IP)), UJ53 and UJ57 (90 and 120 m from CMS IP), RR53 and RR57 (240 m from CMS IP), TI18 (480 m from ATLAS IP). The potential sites are studied on the basis of (a) expectations for neutrino interaction rates, flavour composition and energy spectrum, (b) predicted backgrounds and in-situ measurements, performed with a nuclear emulsion detector and radiation monitors. TI18 emerges as the most favourable location. A small detector in TI18 could measure, for the first time, the high-energy $ν$N cross section, and separately for $τ$ neutrinos, with good precision, already with 300 fb$^{-1}$ in the LHC Run3.
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Submitted 15 March, 2019;
originally announced March 2019.
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A Letter of Intent for MATHUSLA: a dedicated displaced vertex detector above ATLAS or CMS
Authors:
Cristiano Alpigiani,
Austin Ball,
Liron Barak,
James Beacham,
Yan Benhammo,
Tingting Cao,
Paolo Camarri,
Roberto Cardarelli,
Mario Rodriguez-Cahuantzi,
John Paul Chou,
David Curtin,
Miriam Diamond,
Giuseppe Di Sciascio,
Marco Drewes,
Sarah C. Eno,
Erez Etzion,
Rouven Essig,
Jared Evans,
Oliver Fischer,
Stefano Giagu,
Brandon Gomes,
Andy Haas,
Yuekun Heng,
Giuseppe Iaselli,
Ken Johns
, et al. (39 additional authors not shown)
Abstract:
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 particle…
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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.
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Submitted 2 November, 2018;
originally announced November 2018.
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CMS-XSEN: LHC Neutrinos at CMS. Experiment Feasibility Study
Authors:
S. Buontempo,
G. M. Dallavalle,
G. De Lellis,
D. Lazic,
F. L. Navarria
Abstract:
We discuss a CMS eXtension for Studying Energetic Neutrinos (CMS-XSEN). Neutrinos at the LHC are abundant and have unique features: their energies reach out to the TeV range, and the contribution of the τ flavour is sizeable. The measurement of their interaction cross sections has much physics potential. The pseudorapity range 4<|η|<5 is of particular interest since leptonic W decays provide an ad…
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We discuss a CMS eXtension for Studying Energetic Neutrinos (CMS-XSEN). Neutrinos at the LHC are abundant and have unique features: their energies reach out to the TeV range, and the contribution of the τ flavour is sizeable. The measurement of their interaction cross sections has much physics potential. The pseudorapity range 4<|η|<5 is of particular interest since leptonic W decays provide an additional contribution to the neutrino flux from b and c production. A modest detector of 4.1x$10^{27}$ nucleons/cm$^{2}$, placed in the LHC tunnel, 25 m from the interaction point, around the focusing magnet (Q1) closest to CMS, can cover that region. The hadronic calorimeter HF and the CMS forward shield will protect it from the debris of pp collisions. With a luminosity of 300/fb, foreseen for the LHC run in the years 2021-2023, the detector can observe over a thousand τ neutrino interactions, and a hundred TeV-neutrino interactions of all flavours. Several backgrounds are considered. A major source can be prompt muons from the interaction point. However, the CMS magnetic field and the structure of the Forward Shield make the estimation of their flux in the location of interest uncertain. Besides, machine induced backgrounds are expected to vary rapidly while moving along and away from the beam line. We propose to acquire experience during the 2018 LHC run by a brief test with a small Neutrino Experiment Demonstrator, based on nuclear emulsions.
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Submitted 12 April, 2018;
originally announced April 2018.