PaperlayerView exact revision on arXiv

Source-linked AI summary

Science Requirements and Detector Concepts for the Electron-Ion Collider: EIC Yellow Report

R. Abdul Khalek, A. Accardi, J. Adam, D. Adamiak, W. Akers, M. Albaladejo, A. Al-bataineh, M. G. Alexeev, F. Ameli, P. Antonioli, N. Armesto, W. R. Armstrong, M. Arratia, J. Arrington, A. Asaturyan, M. Asai, E. C. Aschenauer, S. Aune, H. Avagyan, C. Ayerbe Gayoso, B. Azmoun, A. Bacchetta, M. D. Baker, F. Barbosa, L. Barion, K. N. Barish, P. C. Barry, M. Battaglieri, A. Bazilevsky, N. K. Behera, F. Benmokhtar, V. V. Berdnikov, J. C. Bernauer, V. Bertone, S. Bhattacharya, C. Bissolotti, D. Boer, M. Boglione, M. Bondì, P. Boora, I. Borsa, F. Bossù, G. Bozzi, J. D. Brandenburg, N. Brei, A. Bressan, W. K. Brooks, S. Bufalino, M. H. S. Bukhari, V. Burkert, N. H. Buttimore, A. Camsonne, A. Celentano, F. G. Celiberto, W. Chang, C. Chatterjee, K. Chen, T. Chetry, T. Chiarusi, Y. -T. Chien, M. Chiosso, X. Chu, E. Chudakov, G. Cicala, E. Cisbani, I. C. Cloet, C. Cocuzza, P. L. Cole, D. Colella, J. L. Collins, M. Constantinou, M. Contalbrigo, G. Contin, R. Corliss, W. Cosyn, A. Courtoy, J. Crafts, R. Cruz-Torres, R. C. Cuevas, U. D'Alesio, S. Dalla Torre, D. Das, S. S. Dasgupta, C. Da Silva, W. Deconinck, M. Defurne, W. DeGraw, K. Dehmelt, A. Del Dotto, F. Delcarro, A. Deshpande, W. Detmold, R. De Vita, M. Diefenthaler, C. Dilks, D. U. Dixit, S. Dulat, A. Dumitru, R. Dupré, J. M. Durham, M. G. Echevarria, L. El Fassi, D. Elia, R. Ent, R. Esha, J. J. Ethier, O. Evdokimov, K. O. Eyser, C. Fanelli, R. Fatemi, S. Fazio, C. Fernandez-Ramirez, M. Finger, M. Finger, D. Fitzgerald, C. Flore, T. Frederico, I. Friščić, S. Fucini, S. Furletov, Y. Furletova, C. Gal, L. Gamberg, H. Gao, P. Garg, D. Gaskell, K. Gates, M. B. Gay Ducati, M. Gericke, G. Gil da Silveira, F. -X. Girod, D. I. Glazier, K. Gnanvo, V. P. Goncalves, L. Gonella, J. O. Gonzalez Hernandez, Y. Goto, F. Grancagnolo, L. C. Greiner, W. Guryn, V. Guzey, Y. Hatta, M. Hattawy, F. Hauenstein, X. He, T. K. Hemmick, O. Hen, G. Heyes, D. W. Higinbotham, A. N. Hiller Blin, T. J. Hobbs, M. Hohlmann, T. Horn, T. -J. Hou, J. Huang, Q. Huang, G. M. Huber, C. E. Hyde, G. Iakovidis, Y. Ilieva, B. V. Jacak, P. M. Jacobs, M. Jadhav, Z. Janoska, A. Jentsch, T. Jezo, X. Jing, P. G. Jones, K. Joo, S. Joosten, V. Kafka, N. Kalantarians, G. Kalicy, D. Kang, Z. B. Kang, K. Kauder, S. J. D. Kay, C. E. Keppel, J. Kim, A. Kiselev, M. Klasen, S. Klein, H. T. Klest, O. Korchak, A. Kostina, P. Kotko, Y. V. Kovchegov, M. Krelina, S. Kuleshov, S. Kumano, K. S. Kumar, R. Kumar, L. Kumar, K. Kumerički, A. Kusina, K. Kutak, Y. S. Lai, K. Lalwani, T. Lappi, J. Lauret, M. Lavinsky, D. Lawrence, D. Lednicky, C. Lee, K. Lee, S. H. Lee, S. Levorato, H. Li, S. Li, W. Li, X. Li, X. Li, W. B. Li, T. Ligonzo, H. Liu, M. X. Liu, X. Liu, S. Liuti, N. Liyanage, C. Lorcé, Z. Lu, G. Lucero, N. S. Lukow, E. Lunghi, R. Majka, Y. Makris, I. Mandjavidze, S. Mantry, H. Mäntysaari, F. Marhauser, P. Markowitz, L. Marsicano, A. Mastroserio, V. Mathieu, Y. Mehtar-Tani, W. Melnitchouk, L. Mendez, A. Metz, Z. -E. Meziani, C. Mezrag, M. Mihovilovič, R. Milner, M. Mirazita, H. Mkrtchyan, A. Mkrtchyan, V. Mochalov, V. Moiseev, M. M. Mondal, A. Morreale, D. Morrison, L. Motyka, H. Moutarde, C. Muñoz Camacho, F. Murgia, M. J. Murray, P. Musico, P. Nadel-Turonski, P. M. Nadolsky, J. Nam, P. R. Newman, D. Neyret, D. Nguyen, E. R. Nocera, F. Noferini, F. Noto, A. S. Nunes, V. A. Okorokov, F. Olness, J. D. Osborn, B. S. Page, S. Park, A. Parker, K. Paschke, B. Pasquini, H. Paukkunen, S. Paul, C. Pecar, I. L. Pegg, C. Pellegrino, C. Peng, L. Pentchev, R. Perrino, F. Petriello, R. Petti, A. Pilloni, C. Pinkenburg, B. Pire, C. Pisano, D. Pitonyak, A. A. Poblaguev, T. Polakovic, M. Posik, M. Potekhin, R. Preghenella, S. Preins, A. Prokudin, P. Pujahari, M. L. Purschke, J. R. Pybus, M. Radici, R. Rajput-Ghoshal, P. E. Reimer, M. Rinaldi, F. Ringer, C. D. Roberts, S. Rodini, J. Rojo, D. Romanov, P. Rossi, E. Santopinto, M. Sarsour, R. Sassot, N. Sato, B. Schenke, W. B. Schmidke, I. Schmidt, A. Schmidt, B. Schmookler, G. Schnell, P. Schweitzer, J. Schwiening, I. Scimemi, S. Scopetta, J. Segovia, R. Seidl, S. Sekula, K. Semenov-Tian-Shanskiy, D. Y. Shao, N. Sherrill, E. Sichtermann, M. Siddikov, A. Signori, B. K. Singh, S. Širca, K. Slifer, W. Slominski, D. Sokhan, W. E. Sondheim, Y. Song, O. Soto, H. Spiesberger, A. M. Stasto, P. Stepanov, G. Sterman, J. R. Stevens, I. W. Stewart, I. Strakovsky, M. Strikman, M. Sturm, M. L. Stutzman, M. Sullivan, B. Surrow, P. Svihra, S. Syritsyn, A. Szczepaniak, P. Sznajder, H. Szumila-Vance, L. Szymanowski, A. S. Tadepalli, J. D. Tapia Takaki, G. F. Tassielli, J. Terry, F. Tessarotto, K. Tezgin, L. Tomasek, F. Torales Acosta, P. Tribedy, A. Tricoli, Triloki, S. Tripathi, R. L. Trotta, O. D. Tsai, Z. Tu, C. Tuvè, T. Ullrich, M. Ungaro, G. M. Urciuoli, A. Valentini, P. Vancura, M. Vandenbroucke, C. Van Hulse, G. Varner, R. Venugopalan, I. Vitev, A. Vladimirov, G. Volpe, A. Vossen, E. Voutier, J. Wagner, S. Wallon, H. Wang, Q. Wang, X. Wang, S. Y. Wei, C. Weiss, T. Wenaus, H. Wennlöf, N. Wickramaarachchi, A. Wikramanayake, D. Winney, C. P. Wong, C. Woody, L. Xia, B. W. Xiao, J. Xie, H. Xing, Q. H. Xu, J. Zhang, S. Zhang, Z. Zhang, Z. W. Zhao, Y. X. Zhao, L. Zheng, Y. Zhou, P. Zurita

arXiv:2103.05419v3physics.ins-dethep-exhep-phnucl-exnucl-th

TL;DR

The report addresses the detector requirements needed to realize the EIC’s broad physics program. It studies detector concepts and technologies, finding that coverage and capabilities are sufficient for nearly all inclusive channels, with identified performance tensions.

  • Problem

    Separating non-perturbative functions and establishing TMD-factorization applicability require measurements differential in Q, x, and z across broad kinematic coverage.

  • Method

    The report evaluates detector concepts, tracking-material constraints, and technologies against physics-driven acceptance and performance requirements.

  • Results

    Detector coverage and capabilities are sufficient for nearly all inclusive reaction channels, though electron–pion discrimination and mid-rapidity electron identification remain limited.

  • Takeaways & Limitations

    Developed electromagnetic-calorimetry technologies can meet or nearly meet EIC resolution requirements, with technology choices constrained by geometry and performance needs.

  • Takeaways & Limitations

    SiPMs may limit high-resolution PbWO4 calorimeter performance because large dynamic range requires large-area, high-pixel-density sensors.

Abstract

from arXiv · show

This report describes the physics case, the resulting detector requirements, and the evolving detector concepts for the experimental program at the Electron-Ion Collider (EIC). The EIC will be a powerful new high-luminosity facility in the United States with the capability to collide high-energy electron beams with high-energy proton and ion beams, providing access to those regions in the nucleon and nuclei where their structure is dominated by gluons. Moreover, polarized beams in the EIC will give unprecedented access to the spatial and spin structure of the proton, neutron, and light ions. The studies leading to this document were commissioned and organized by the EIC User Group with the objective of advancing the state and detail of the physics program and developing detector concepts that meet the emerging requirements in preparation for the realization of the EIC. The effort aims to provide the basis for further development of concepts for experimental equipment best suited for the science needs, including the importance of two complementary detectors and interaction regions. This report consists of three volumes. Volume I is an executive summary of our findings and developed concepts. In Volume II we describe studies of a wide range of physics measurements and the emerging requirements on detector acceptance and performance. Volume III discusses general-purpose detector concepts and the underlying technologies to meet the physics requirements. These considerations will form the basis for a world-class experimental program that aims to increase our understanding of the fundamental structure of all visible matter

Author List

The report is authored by a large international collaboration of researchers affiliated with institutions across the United States, Europe, Asia, Australia, and South America.

  • Institutional affiliations: The collaboration includes major U.S. national laboratories and universities, including Jefferson Lab and Brookhaven National Laboratory.Institutional affiliations listed include Thomas Jefferson National Accelerator Facility and Brookhaven National Laboratory.
  • Institutional affiliations: The affiliations also span institutions in Europe, Asia, Australia, and South America.Examples include universities and research institutes in the Netherlands, Italy, India, Saudi Arabia, Argentina, Chile, China, and the Czech Republic.

10 Detector Challenges & Performance Requirements

This section organizes the EIC detector requirements around beam conditions, integration with the interaction region, event rates, backgrounds, systematic uncertainties, and physics performance.

  • 10.1 Beam Energies, Polarization, Versatility, Luminosities: The section first addresses beam energies, polarization, versatility, and luminosities as core detector-design considerations.
  • 10.2 Integrated Detector and Interaction Region: It then considers the integrated detector and interaction region as a combined design challenge.
  • 10.3 Rate and Multiplicities: The requirements also account for event rates and particle multiplicities that detectors must handle.
  • 10.4 Backgrounds: Background processes are treated as a distinct challenge for detector performance.
  • 10.5 Systematic Uncertainties: Systematic uncertainties are identified as another component of the detector-performance requirements.
  • 10.6 Physics Requirements: The section concludes by specifying physics requirements that guide the detector concepts.

11 Detector Aspects … The Electron-Ion Collider

The EIC Yellow Report organizes detector aspects spanning magnets, tracking, calorimetry, particle identification, forward and backward detection, technologies, readout, software, and artificial intelligence. It situates these detector studies within the EIC’s high-luminosity, polarized electron–ion program and the EIC User Group’s coordinated design effort.

  • 11 Detector Aspects: The detector program covers magnets, tracking, electromagnetic and hadron calorimetry, particle identification, and far-forward and far-backward detectors.These topics comprise the principal detector-aspect studies in Chapter 11.
  • 11 Detector Aspects: The report also addresses detector technologies and challenges, polarimetry, readout electronics and data acquisition, software and data preservation, and artificial intelligence for the EIC detector.These sections extend the detector discussion from hardware components to instrumentation, computing, and analysis infrastructure.
  • 11 Detector Aspects: The detector concepts include dedicated discussions of silicon-vertex tracking, tracking, particle identification, electromagnetic and hadronic calorimetry, auxiliary detectors, data acquisition, and electronics.These topics are presented as detector-design components in a subsequent set of concept studies.
  • The Electron-Ion Collider: The EIC is presented as a major U.S. accelerator project whose high design luminosity and highly polarized beams are intended to address open questions in the fundamental structure of matter.Its realization is described as pushing accelerator and detector technology beyond the state of the art.
  • The Electron-Ion Collider: The EIC is designed for ion beams from deuterons to heavy nuclei, variable e+p center-of-mass energies of 20−100 GeV upgradable to 140 GeV, and the possibility of more than one interaction region.These accelerator conditions define the operating scope that detector concepts must accommodate.
  • The Electron-Ion Collider: The collider will combine high collision luminosity, polarized nucleon beams, nuclear beams, and sophisticated large detectors to measure reactions probing nucleon and nuclear structure.The stated science reach concerns previously inaccessible aspects of nuclear structure in terms of quark and gluon constituents.
  • The Electron-Ion Collider: The Yellow Report summarizes an EIC User Group initiative intended to advance the physics measurements and scientific equipment needed for the facility.The initiative was organized by the EIC User Group, which included over 1200 members from 245 institutions in 33 countries.
  • The Electron-Ion Collider: The report’s detector and physics studies were developed through an initial December 2019 meeting followed by four meetings in 2020 involving the EIC User Group.The listed meetings took place at MIT, Temple University, the University of Pavia, the Catholic University of America, and the University of California, Berkeley.

Physics Measurements and Requirements … Nonperturbative charm

The EIC physics program targets nucleon, nuclear, and hadronic structure through inclusive, semi-inclusive, exclusive, polarized, and jet measurements, while motivating specific machine, detector, technology, and computing requirements. Its broad reach includes spin and mass, multidimensional imaging, gluon saturation, hadronization, nuclear modifications, precision PDFs, and possible nonperturbative charm.

  • Physics Measurements and Requirements; The EIC Physics Case; 1. Global properties and parton structure of hadrons; 2. Multi-dimensional imaging of nucleons, nuclei and mesons: The EIC will use polarized e+p and e+A collisions to probe nucleon spin and mass, multidimensional parton structure, mesons, nuclear QCD, and hadronization.Measurements will map quark and gluon momentum structure over wide x and Q2 ranges, constrain helicity distributions down to x ∼10^-4, and provide information on multi-dimensional nucleon, nuclear, and meson structure.
  • 3. The nucleus: a laboratory for QCD; Physics Measurements and Requirements: The EIC’s broad energy, luminosity, polarization, and ion-species program is designed to expose nuclear effects, nonlinear QCD, gluon saturation, and parton transport through nuclei.Saturation studies require high energies with heavy nuclei, good tracking, forward calorimetry, Roman pots, and stringent hermeticity; varying nuclear size enables studies of heavy-flavor modification and transport.
  • 4. Understanding hadronization; Imaging in momentum space — transverse momentum dependent parton dis-; Physics Measurements and Requirements: Jets, identified hadrons, fragmentation functions, and leading-jet measurements will study gluon helicity, TMDs, hadronization, cold nuclear matter, and parton energy loss.The EIC’s luminosity and multiple beam species enable polarized and nuclear-medium hadronization studies, including polarized Λ and di-hadron fragmentation, while high center-of-mass energy and broad nuclear-size coverage are required for clean jet measurements.
  • Detector Concepts; 3.5 Two Complementary Detectors; Physics Measurements and Requirements: Detector concepts prioritize broad acceptance, tracking, calorimetry, particle identification, hermeticity, and forward instrumentation, with all-silicon and hybrid tracking options supporting complementary interaction-region designs.The report presents multiple detector concepts and concludes that two detectors differing in solenoid fields and subdetector technologies optimize science output.
  • Opportunities for Detector Technology and Computing; CHAPTER 4. OPPORTUNITIES FOR DETECTOR TECHNOLOGY AND COMPUTING31; CHAPTER 4. OPPORTUNITIES FOR DETECTOR TECHNOLOGY AND COMPUTING33: Modern streaming readout, statistical analysis, and AI could integrate detector operation and near-real-time nuclear-physics analysis from the experiment’s outset.The proposed approach uses synchronized, self-calibrated detector data and builds on machine-learning decisions already used for near-real-time data selection at LHCb.
  • Introduction to Volume II; Detector Concepts; Opportunities for Detector Technology and Computing: The Yellow Report establishes detector requirements and emerging technologies as a community basis for EIC realization, while identifying opportunities in material reduction, particle identification, calorimetry, and photodetector readout.It documents progress toward EIC construction and guides further studies and development of actual detectors.
  • Inclusive neutral-current and charged-current DIS; Positron beam; Parity-violating DIS; Tagged DIS; Sea quark PDFs via SIDIS measurements: The EIC will constrain PDFs and nuclear PDFs with inclusive NC and CC DIS, positron data, parity-violating observables, tagged DIS, and SIDIS measurements.Projected data provide more than 5σ average discrimination between PDF hypotheses across the acceptance, strongly improve x(s + ¯s) at low x, improve flavor determination and d/u at large x, and clarify nuclear effects including the EMC effect [74].
  • Nonperturbative charm: Charm tagging and large-x measurements can probe intrinsic charm, while EIC constraints on a nonperturbative charm component complement LHC information.Charm-tagging capabilities are expected to improve separation of a possible nonperturbative charm contribution from other nucleon-structure effects.

Charm jets … Twist-3 PDF gq

The EIC program is projected to constrain nucleon flavor, spin, orbital-angular-momentum, meson, and higher-twist structure through complementary inclusive, tagged, exclusive, jet, and semi-inclusive measurements. Across these studies, projected data substantially reduce PDF uncertainties while sensitivity depends on low-x extrapolations, symmetry assumptions, nuclear effects, and factorization limitations.

  • Charm jets: Charm-jet production strongly depends on Rs = 0.325 versus Rs = 0.863, making it sensitive to nucleon strangeness and SU(3) symmetry breaking.The scenarios correspond to suppressed and enhanced strangeness in CT18 NNLO PDF sets.
  • 7.1.2 Spin structure of the proton and neutron: EIC pseudodata significantly reduce gluon-helicity uncertainty relative to DSSV14 [87] [88], while truncated-moment improvements reach 80−90% for ∆Gtrunc and approximately 80% for ∆Σtrunc under SU(3) symmetry.Without SU(3) symmetry, ∆Gtrunc uncertainty decreases by approximately 60%, while proton data alone show no clear ∆Σtrunc reduction.
  • Helicity and small-x dipole formalism: Small-x helicity predictions will be sharpened by EIC data, but extrapolation uncertainties remain formalism-dependent because the KPS and JAM approaches produce different uncertainty bands.The KPS equations resum powers of αs ln2(1/x) for polarized color-dipole evolution.
  • Neutron spin structure from inclusive and tagged DIS with polarized 3He and 2H: Polarized 3He, deuteron, and spectator-tagged DIS jointly improve neutron-structure extraction by controlling nuclear effects, with on-shell extrapolation enabling accurate determination of the free-neutron asymmetry.Deuteron tagging fixes the nuclear configuration and permits differential treatment of nuclear effects.
  • Orbital angular momentum contribution to nucleon spin: EIC coverage of poorly known GPD E and low-x GPDs enables flavor-separated quark and gluon orbital-angular-momentum contributions to the proton spin to be determined.Exclusive DVCS and meson-production measurements connect GPDs to parton transverse structure and Ji’s relation.
  • Parity-violating DIS: Parity-violating DIS can add flavor-sensitive helicity constraints, while SIDIS with identified pions and kaons substantially improves access to sea-quark helicities over inclusive DIS.The parity-violating impact on ∆Σ is approximately 30% at low xmin with JAM17 [90] axial charges but is diminished under hyperon-decay SU(3) assumptions.
  • Meson structure function projections: Leading-neutron measurements extend pion structure-function coverage to mid-to-high x, while projected EIC data reduce sea-quark and gluon PDF uncertainties by approximately a factor of 5−10 over most x.The meson program broadens access in x, Q2, and −t, including small −t, to probe pion and kaon gluonic structure.
  • Twist-3 PDF gq: Twist-3 observables probe multiparton correlations, but factorization and unknown twist-3 distributions complicate extraction; semi-inclusive jets and gT measurements provide complementary access to gqT(x).Global analyses can simultaneously improve twist-3 collinear functions and twist-2 TMD knowledge, while EIC gT data reveal interactions between struck quarks and surrounding partons.

Inclusive diffraction … Introduction

The EIC program targets diffraction through expanded leading-proton coverage, sensitivity to diffractive structure functions and parton distributions, and tests of Pomeron dynamics, while 1-jettiness provides an event-shape probe of αs and hadronization effects.

  • Inclusive diffraction: EIC instrumentation will measure leading protons across a much wider range of t and xL than HERA, expanding access to QCD diffraction.The accessible t and xL ranges depend on small-angle final-state proton acceptance and EIC beam-energy scenarios.
  • Inclusive diffraction: At 18 × 275 GeV, EIC measurements can separate Pomeron and Reggeon contributions and access longitudinal diffractive structure through variable energies and high luminosity.HERA lacked sufficient ξ coverage to test the Reggeon t-dependence in its dominant region, whereas the EIC contribution to F_D^L is non-negligible there.
  • Inclusive diffraction: EIC data could improve DPDF extraction, especially where HERA fits were limited by low-Q2 failures and weak constraints at large partonic z.The HERA fits applied only above Q2 > 8.5 GeV2 for H1 and Q2 > 5 GeV2 for ZEUS; saturation models may incorporate higher-twist corrections.
  • Diffractive dijets: Diffractive dijet photoproduction predictions have a nearly constant NLO-to-LO K-factor of approximately 2 and show strong sensitivity to the chosen DPDF set, particularly at large zobs_IP.The predicted average jet transverse momentum extends only to 8 GeV, so direct-photon contributions dominate.
  • Large-|t| diffractive production of vector mesons: EIC luminosity and detector acceptance could test BFKL-model cross-section dependence on rapidity gaps up to four units, with acceptance to η = 3.5 sufficient.HERA could not directly measure this dependence because of limited rapidity acceptance.
  • Introduction: Event shapes characterize final-state momentum collimation and provide probes of QCD predictions, αs, and hadronization effects.For thrust, τ → 0 describes pencil-like two-jet events, while larger τ corresponds to broader jets.
  • Introduction: DIS 1-jettiness measures deviations from collimated beam-plus-jet configurations, with τ1 → 0 for perfectly collimated regions and τb1 requiring only current-hemisphere measurements.The alternative τa1 requires particles from both beam and current hemispheres.

Theoretical precision … Helicity TMDs and PDFs at small x

The report develops precision QCD methods and a broad EIC program to image nucleon and nuclear structure through GPDs, TMDs, Wigner distributions, jets, and small-x observables. It emphasizes high-precision extractions, complementary channels, and detector capabilities needed to probe spin, momentum, spatial, mechanical, and saturation phenomena.

  • Theoretical precision; Event shapes: Precision event-shape theory combines factorization, renormalization-group resummation, nonsingular matching, and universal nonperturbative corrections to reach N3LL accuracy and support percent-level αS sensitivity.Theoretical uncertainties improve at larger Q, while finite hadron masses, renormalon subtraction, higher-order nonsingular terms, and experimental cuts remain important corrections.
  • Impact parameter distributions: EIC measurements can constrain GPDs sufficiently to extract quark and gluon impact-parameter densities and probe gluon spatial distributions over two orders of magnitude in xV.The studies use DVCS-constrained GPDs and projected |t|-differential heavy-vector-meson measurements to access spatial structure.
  • Unpolarized TMDs and TMD evolution: EIC TMD measurements require broad (Q, x, z) coverage to separate TMD PDFs, TMD fragmentation functions, and the nonperturbative Collins-Soper kernel, whose fine structure can probe QCD-vacuum properties.The factorization receives power corrections in δ ∼ PT/(zQ), while projected data can substantially improve knowledge of the poorly constrained TMD flavor structure.
  • Quark Sivers and Collins measurements; Gluon TMD measurements; Chiral-odd distribution functions via di-hadron measurements; Medium modification of azimuthal modulations in SIDIS: Polarized SIDIS, dihadron, jet, and nuclear measurements can substantially improve spin-structure extractions, including tensor charges, Collins and Sivers functions, transversity, and medium-induced transverse-momentum broadening.Projected gluon-Sivers sensitivity reaches 5% of the positivity bound, while EIC data can reduce the Collins-function uncertainty and make tensor-charge uncertainties comparable to or smaller than current lattice-QCD calculations.
  • Jet-based TMD studies: electron-jet Sivers, hadron-in-jet Collins, and TMD evolution with substructure; Special opportunities with jets and heavy quarks; Event shapes: Jet observables provide complementary access to TMD evolution, flavor-dependent nuclear effects, hadronization, and three-dimensional nucleon and nuclear structure by separating fragmentation and exploiting jet substructure.Jets can deconvolve TMD PDFs from fragmentation functions, while angularity supports flavor-tagging and studies of hadronization in vacuum and nuclear media.
  • Wigner functions; Gluon TMD measurements: The EIC can access gluon Wigner distributions at small x through exclusive dijets, offering information on canonical orbital angular momentum that is complementary to GPD-based kinetic orbital angular momentum.The method exploits the proton recoil momentum and total dijet momentum as two external transverse vectors; the forward limit connects the relevant gluon GTMD to the gluon Sivers function and QCD odderon.
  • Coherent DVCS on light nuclei; Tensor polarized deuteron; Short range correlations and the structure of light nuclei: Exclusive measurements on deuteron, helium, and other nuclear targets exploit recoil and fragment detection to isolate neutron information, constrain tensor polarization and short-range dynamics, and study nuclear effects.Coherent polarized 3He DVCS is promising for neutron extraction, while tagged tensor-polarized DIS can access spin-orbit effects and Azz can reach −2 and +1 with spectator tagging.
  • Inclusive cross sections at small x; Accessing low-x gluons via di-jets or di-hadrons; Recent Progress in Probing Gluon Saturation with Jet Observables: At small x, inclusive e+A cross sections can test nuclear shadowing and saturation, while back-to-back dijet and dihadron correlations can directly probe the previously unmeasured Weizsäcker-Williams gluon distribution.Detector smearing is projected to have negligible impact under the current EIC tracking-resolution design, and multiparticle correlations can determine whether saturation has been reached.

Inclusive diffraction with nuclei … Detector Requirements

The EIC’s broad kinematic reach, polarized light-ion beams, forward detection, and high luminosity enable precision studies of nuclear PDFs, diffraction, short-range correlations, hadronization, jet modification, and nucleon structure. These measurements require accurate control of detector acceptance, resolution, and coherent–incoherent event separation.

  • Inclusive diffraction with nuclei: Hard diffractive events may comprise 30-40% of the cross-section in some saturation models, contrasting with the smaller fraction and nuclear suppression expected from DGLAP-based non-saturation descriptions.Extracting nuclear diffractive PDFs requires reduced systematic uncertainty and separation of coherent from incoherent diffraction.
  • nPDFs via inclusive DIS: The EIC will broaden nuclear-PDF kinematic coverage, achieve inclusive DIS systematic uncertainties of at most a few percent, and significantly reduce low-x theoretical uncertainties.Inclusive measurements can support robust extraction of nuclear A dependence and a combined proton, deuteron, and nuclear PDF analysis.
  • Flavor-tagged jets and the jet charge: Jet charge, angularities, electron-jet correlations, jet substructure, and energy-flow correlations provide constraints on isospin, nuclear PDFs, parton transport, fragmentation, hadronization, and target fragmentation.Inclusive-jet charge modifications are about 30%, while electron-jet momentum balance, azimuthal correlations, and substructure offer orthogonal constraints on transport coefficients.
  • Coherent scattering off the lightest nuclei: Diffractive J/psi, coherent light-nucleus scattering, and polarized deuteron measurements can probe gluon densities, nuclear wave functions, rescattering, and multi-nucleon amplitudes across experimentally accessible momentum transfer.For coherent light-nucleus studies, the predicted diffractive-minimum shift at x = 10^-3 is measurable if detector acceptance covers -t ≲ 0.5 GeV^2.
  • Studying short-range correlations with an EIC: Forward detectors, polarized light ions, and spectator tagging enable controlled studies of EMC effects, spin structure, short-range correlations, nuclear breakup, and effective free-neutron targets.Simulations indicate strong recoil acceptance, although neutron acceptance is lower at the lower energy setting; double-spectator tagging can constrain initial nucleon momentum with minimal model dependence.
  • Separating coherent and incoherent production: Coherent and incoherent vector-meson measurements can image nuclear gluon distributions and fluctuations, but coherent extraction requires better than 400:1 incoherent rejection at the third diffractive minimum.The cited simulation achieves only 100:1 rejection by vetoing neutrons, protons, and photons above 50 MeV, making detector control of forward activity essential.
  • Light meson fragmentation functions and flavor sensitivity: The EIC will extend polarized and nuclear fragmentation studies, including light-meson, polarized-Lambda, di-hadron, and nuclear fragmentation functions, while heavy-meson reconstruction and jet substructure probe flavor-dependent in-medium evolution.Heavy-meson signals are obtained over combinatorial backgrounds, and the EIC can measure transverse-momentum-dependent fragmentation and nuclear modifications with high precision.

Systematic uncertainties for the inclusive pseudo-data … Scintillating fibers embedded in absorber

The report finds that the proposed detector concepts broadly support inclusive, SIDIS, jet, heavy-flavor, exclusive, and spectroscopy measurements, while identifying particle identification, forward and low-Q2 acceptance, vertexing, calorimetry, and continuous coverage as key performance constraints. It also evaluates detector technologies and reconstruction methods, showing where performance is robust and where degradation directly limits physics reach.

  • Systematic uncertainties for the inclusive pseudo-data: The proposed detector coverage and capabilities support nearly all inclusive channels, but limited e−/π− discrimination for η > −2 would systematically constrain APV and ALL at mid-rapidity.Reduced mid-rapidity electron PID is the principal tension identified for inclusive measurements.
  • Detector requirements: Three-σ π−K separation keeps di-hadron sample purities above 95%, whereas lower separation reduces πK purity below 70% and KK purity to about 75%.The study identifies three-σ hadron separation as important for precision kaon measurements.
  • Detector requirements: SIDIS performance requires broad PID momentum coverage, low minimum reconstruction thresholds, and forward tracking and calorimetry to η < 4; restricted barrel PID significantly reduces intermediate-x, high-Q2, and higher-z reach.Hadronic reconstruction improves DIS and SIDIS reconstruction at high x, moderate Q2, low y, and low pTjet compared with electron-only methods.
  • Momentum resolution: Tracking momentum resolution has negligible impact on JES and JER, but tracking thresholds and efficiency remain important for jet substructure and heavy-flavor physics.Lowering the threshold to 100 MeV/c raises acceptance from 60% to 90% at mid-rapidity and from 20% to 70% at |η| = 3; degrading vertex resolutions from 20 µm to 100 µm causes a 60% loss in charm-jet efficiency.
  • Comparison: requirements versus performance: The detector-technology studies compare silicon, gaseous, hybrid, homogeneous, sampling, crystal, glass, lead-glass, and scintillating-fiber calorimeter concepts against the stated tracking, calorimetry, PID, timing, and coverage requirements.The supplied passages identify these detector concepts and requirements as the report’s framework for developing complementary EIC experimental systems.
  • Hadron calorimetry: Jet measurements require full central hadron-calorimeter coverage and minimal calorimeter gaps, because forward resolution, neutral-hadron response, and electromagnetic gaps can bias jet observables and complicate background rejection.The hadron-calorimeter request covers −3.5 < η < 3.5, while a gap in electromagnetic calorimetry has a larger effect than a hadron-calorimeter gap.
  • Systematic uncertainties for the inclusive pseudo-data: For 1-jettiness at 30 < Q < 40 GeV, unfolded statistical uncertainties are within 2% and detector-related systematic uncertainties are about 4%, with total uncertainties of roughly 2–4% across the distribution.These few-percent uncertainties are below the typically 10% systematic uncertainties reported for HERA αS extractions using inclusive jet cross sections [1376].
  • Forward detector: Exclusive and threshold measurements are primarily limited by low-Q2 and forward acceptance: the nominal |η| < 3.5 detector covers most decay products, while low-Q2 tagging and Roman Pot thresholds control photoproduction, Υ-threshold statistics, and nuclear t reach.Roman Pots reaching pT = 0.2 GeV correspond to −t ≈ 0.04 GeV2; degrading this threshold strongly affects the extracted nuclear density-profile error.

Shashlyk … Far-Backward Electron Detection and Requirements

The report develops detector concepts and requirements spanning calorimetry, particle identification, far-forward tagging, Roman Pots, luminosity monitoring, and associated interaction-region instrumentation for the EIC. These studies establish performance targets, identify technology trade-offs and limitations, and provide a foundation for further detector and interaction-region design.

  • Photon Detection Technology Options: Particle-identification technologies face important limitations from chromaticity, optical aberrations, pixelation, photocathode aging, magnetic-field sensitivity, and photon-detector signal loss.CsI efficiency degrades above an integrated charge of 1 mC/cm2, LAPPD devices are limited by magnetic-field sensitivity and signal loss, and SiPM operation benefits from temperatures below -30°C and post-annealing.
  • Dual RICH (dRICH): The dRICH combines aerogel and C2F6 gas radiators to cover the full momentum range without low- or intermediate-momentum PID holes, while meeting the π-K requirements.Its aerogel resolution is dominated by radiator chromaticity, and calculations indicate that switching to Ar at 3 atm would have an insignificant performance impact but create an engineering challenge for material budget.
  • Forward Region: Forward hadron identification requires gas-based Cherenkov detection at high momentum plus an additional low-threshold technology, making the dRICH an integrated solution for the desired dynamic range.The mRICH extends e-π rejection to roughly 2 GeV/c and π-K separation to roughly 6–7 GeV/c, while hpDIRC π-K separation reaches 6 GeV/c with close to a factor-of-two improvement over BaBar.
  • Summary of the Current Design Constraints: Roman Pots require approximately 25 cm × 10 cm of active sensor area, 500 µm × 500 µm pixels, multiple sensor planes for redundancy, and approximately 35 ps timing per plane.These requirements address transverse-momentum coverage, smearing, background rejection, and vertex-smearing reduction from crab-cavity rotation.
  • Spectator Proton and Neutron Tagging in e+3He and e+3H Collisions: Spectator-tagging studies find promising proton double-tagging efficiency, generally above 85% and above 90% at higher energy, with the lower-energy SRC case above 75%.Acceptance losses arise mainly when scattered particles exceed apertures or are lost in the accelerator lattice; neutron tagging is also good but is reduced in SRC events by larger scattering angles.
  • General Layout of Far-Forward IR Region: The far-forward region requires coordinated coverage from Roman Pots, a high-resolution zero-degree calorimeter, a silicon spectrometer, and silicon planes around the beam pipe.Further simulations are needed as the interaction-region design progresses, but the studies provide a foundation for future detector validation and design.
  • Luminosity Measurement and Bremsstrahlung Photons: Luminosity monitoring must support absolute cross sections, combining different running periods, and asymmetry measurements, while bremsstrahlung detection at EIC luminosity requires handling over 20 photons per bunch crossing for electron-proton scattering.Electron taggers can improve photon-acceptance knowledge and reduce the luminosity scale uncertainty to approximately 1%; spectrometer geometry sets a low-energy cutoff in the photon spectrum.

Far-Backward Electron Detector Implementation … 3He Polarimetry at the EIC

The report develops far-backward electron detectors with complementary tagger and ECAL acceptance, while outlining detector-performance challenges and polarimetry concepts for the EIC program. Simulations indicate broad kinematic coverage but identify transition-region, reconstruction, particle-identification, calorimetry, and polarization-measurement requirements that motivate further detector development.

  • Far-Backward Electron Detector Implementation: The backward-detector study uses Geant4 models and Pythia 6 plus quasi-real photoproduction samples at 18 × 275 GeV to evaluate tagger and ECAL acceptance.The quasi-real photoproduction model follows a HERA approach implemented in eic-lgen.
  • Far-Backward Electron Detector Implementation: The combined tagger–ECAL system provides complementary backward-electron energy coverage and broad Q2 acceptance, with a transition dip near Q2 ∼0.1 GeV2 that depends strongly on the ECAL inner radius.Tagger 1 is placed at z = −24 m, Tagger 2 at z = −37 m, and the backward ECAL at z = −3.28 m with simulated coverage of approximately −4.0 < η < −1.0.
  • Far-Backward Electron Detector Implementation: Electron-based Q2 reconstruction remains reasonable down to 10−3 GeV2 but becomes meaningless below 10−4 GeV2 because beam angular divergence causes significant smearing.The reconstructed-versus-generated comparison includes smearing from beam angular divergence.
  • 11.8.1 Acceptance requirements for the central detector: The reference detector’s overall acceptance matches the EIC physics program, but barrel PID performance does not presently meet requirements for electron–pion separation and hadron identification.The report identifies pion-suppression and high-momentum hadron-PID demands as requiring further assessment and technological support.
  • 11.8.3 Hadron calorimetry challenges: Forward calorimetry presents a discrepancy for η > 3: achieving a constant term of ∼5% would improve jet resolution, but high-resolution inserts require additional R&D and substantial space.Existing technologies may satisfy requirements up to η ∼3, whereas η > 3 motivates options such as high-density fiber calorimetry with SiPM readout.
  • 11.9 Polarimetry: EIC beam polarimetry must be rapid, non-destructive, bunch-resolved, and accurate to about 1% or better to support physics measurements and accelerator setup.Polarization uncertainty propagates directly into asymmetry uncertainties, motivating timely quasi-online feedback.
  • 11.9.1 Electron Polarimetry: Compton polarimeters at IP 12 or IP 6 can measure longitudinal and transverse electron polarization, requiring energy-sensitive photon/electron detection and position-sensitive detectors for the transverse up-down asymmetry.At high beam energy the narrow photon cone sets stringent segmentation requirements; the detector size is about 8 cm × 1 mm, while synchrotron-radiation backgrounds require beamline mitigation.
  • 11.9.1 Electron Polarimetry: For RCS polarimetry, a Compton polarimeter during flat-top operation is preferred, while a Møller polarimeter in the transfer line is a fallback with reduced precision and greater beamline impact.Transfer-line measurements would average over several bunches and be slowed by the approximately 10 nA beam current [1676].

R&D Studies at RHIC · Readout electronics terms

RHIC polarized-proton and polarized-3He running will provide opportunities to test and develop EIC polarimetry technologies and measurements. The readout and data-acquisition section defines key electronics terms and frames architectures around detector characteristics, data flow, and physics requirements.

  • R&D Studies at RHIC: RHIC polarimeters will support physics measurements during anticipated 2022 and 2024 polarized-proton runs and studies guiding EIC polarimetry development.These runs occur before EIC construction begins.
  • R&D Studies at RHIC: Proposed proton-running tests include second detector layers for punch-through tagging, replacement technologies for carbon targets, and a neutron-based UPC polarimeter requiring a high-Z target and downstream zero-degree calorimeter.The second-layer study applies to detectors in both Hjet and pC polarimeters.
  • R&D Studies at RHIC: Polarized 3He beams, becoming available first at injection energy and later up to approximately 58 GeV/nucleon, can support polarimetry studies during scheduled accelerator-physics experiments.An absolute polarimeter may also be equipped with a possibly polarized 3He target.
  • R&D Studies at RHIC: 3He beam and target combinations enable tests of breakup tagging, energy-TOF and energy-angle relations, and beam or target asymmetries for 3He+3He and 3He+C scattering.With both beam and target polarized, the beam polarization may also be measured as in Eq. 11.18.
  • 11.10.1 Introduction: Readout electronics process detector signals into digital representations, while DAQ collects, filters, and stores the resulting data.Together, these systems are essential components of future EIC detectors.
  • 11.10.1 Introduction: Readout architecture strongly affects the EIC physics program because front-end electronics must match sensor and measurement characteristics, while DAQ must accommodate data flow and may require filtering.The section reviews candidate architectures, validation efforts, and front-end-electronics state of the art under assumed detector and data-flux conditions.
  • Readout electronics terms: The glossary establishes reference definitions for ambiguous readout and DAQ terminology, including front-end electronics, amplification, digitization, buffering, peaking and occupation times, analog memory, and TDCs.Front-end electronics may include signal shaping, digitization, data treatment, buffering, and transfer logic; bufferization can concentrate, temporarily store, select, or reconstruct digital values.

Data acquisition system terms … Examples of readout chips

The EIC readout strategy spans triggered, buffered, and streaming architectures, with the design effort favoring an integrated full streaming-readout system to support flexible online reconstruction and physics analysis. Detector-specific signal, timing, channel-count, radiation, data-rate, and engineering constraints motivate multiple front-end solutions and state-of-the-art readout chips.

  • Data acquisition system terms: A triggered readout sends partial trigger data to hardware logic for decisions, whereas pipelined systems buffer front-end events for asynchronous backend readout.Higher-level filtering can reduce deadtime or data volume, but trigger logic may bias collected data and be difficult to adapt or characterize.
  • Data acquisition system terms: Streaming readout independently timestamps above-threshold channel data and sends it to CPU farms, while unfiltered readout stores every detector hit with minimal zero suppression.Online processing may perform feature extraction, physics analysis, and algorithmic data selection before long-term storage.
  • 11.10.3 Overview on DAQ Structure: Triggerless operation is intended to extend the EIC physics program and enable seamless DAQ-to-analysis workflows, including near-real-time calibration, alignment, and emerging AI/ML technologies.This flexibility is especially relevant for rare exclusive final states requiring multiple sophisticated selection algorithms, such as kaon-rich hadron-spectroscopy reactions.
  • 11.10.3 Overview on DAQ Structure: The EIC team is developing a full streaming-readout DAQ system integrating all detector components, replacing hardware-trigger limitations with software-based reconstruction and selection.Triggerless operation can use all detector information, apply calibration and sophisticated reconstruction online, and support precise selections of complex final states.
  • 11.10.4 Constraints and Environment: The EIC detector’s heterogeneous technologies require distinct readout solutions, with anticipated timing demands from 10–20 ps for psTOF to up to 20 µs for TPC signals.The anticipated channel count suggests three, possibly four, readout solutions, while radiation, cooling, space, standards, and online data-quality feedback add constraints.
  • Introduction: The readout chain performs pre-amplification, shaping, digitization, data treatment, buffering, concentration, and transfer, with front-end gain and shaping matched to detector signal amplitudes and rates.Silicon MAPS integrate front-end processing and adjustable-threshold zero suppression, whereas gaseous detectors require low-noise amplification and timing or charge measurement.
  • Front-end electronics: The modeled EIC collision signal rate is approximately 100 Gbps at L = 10^34 cm^-2s^-1 for the sPHENIX-based detector concept, including conservative MAPS noise.The estimate includes e+p collision and p-p beam-gas contributions for the detector components and motivates substantial DAQ processing capacity.
  • Digitization and data treatment: Readout chips support continuous or triggered digitization, waveform or selective-value sampling, analog memories, and data-reduction algorithms such as common-mode correction, zero suppression, and peak finding.Examples include VMM, TIGER, and SAMPA: VMM combines time and amplitude detection with multi-ADC buffering, while SAMPA provides 32-channel digitization, DSP, and 3.4 Gbit/s bandwidth suited to MPGD and TPC applications.

Support system … The RCDAQ Data Acquisition System

The report outlines future readout-chip requirements and reviews streaming DAQ architectures relevant to EIC experiments. It highlights sPHENIX’s streaming-oriented implementation and RCDAQ’s broad adoption across EIC R&D and external groups.

  • Support system: A prospective EIC readout solution requires a >64-channel mixed-signal ASIC with 10-bit/12-bit SAR ADCs, ≥25 MHz sampling, INL <2.0%, latency <10.0 ns, high-resolution TDC, buffering, glue logic, and FPGA firmware.No single existing chip satisfies all vital requirements, so further evaluation and refinement are needed.
  • Support system: Collaborative development involving CEA, INFN Torino, and Brookhaven could advance the ASIC, mixed-signal, hardware, firmware, and software technologies needed for EIC front-end readout.The report identifies these institutions as promising development sites based on their prior chip work.
  • LHCb streaming readout DAQ: Existing streaming DAQ examples include LHCb’s upgrade to acquire and select events at the full 30 MHz proton-proton collision rate using front-end electronics operating at the bunch-crossing frequency.The LHC rate is 40 MHz nominally, but the LHCb interaction point has a 30 MHz physics-event rate because one in four crossings is empty.
  • sPHENIX Hybrid DAQ: sPHENIX combines triggered calorimeter and streaming tracker readout, using timestamped front-end data, FPGA aggregation, O(1000) multi-Gbps links, and O(10) Tbps overall bandwidth.Its tracking front ends include ALPIDE, PHFX, and V5 ALICE SAMPA-based systems.
  • sPHENIX Hybrid DAQ: sPHENIX’s FELIX-based back end uses O(50) FPGA readout cards with 48 bidirectional 10-Gbps optical links and a 100-Gbps PCIe Gen3 host connection.The cards read, buffer, and process streaming data in commodity Linux PCs.
  • sPHENIX Hybrid DAQ: The sPHENIX architecture supports trigger-based throttling or triggerless recording, while timestamp synchronization and offline event building reduce the need for a distributed online event builder.Streaming tracker data enable heavy-flavor measurements otherwise inaccessible, and the architecture is intended as an exercise applicable to future EIC experiments.
  • The RCDAQ Data Acquisition System: RCDAQ supports sPHENIX front ends, triggered and streaming modes, and numerous commercial readout devices through plugins for R&D, test beams, calibration, and laboratory work.It has become the de-facto DAQ standard for several EIC R&D groups and is used by dozens of external groups because of its device support, ROOT monitoring, controls, and small footprint.

The ERSAP system · Thomas Jefferson Laboratory efforts

The EIC streaming readout effort combines the ERSAP reactive microservice architecture with a progressively deployable, experimentally validated DAQ strategy. Jefferson Laboratory tests used CLAS12 and Hall D to assess streaming reconstruction, filtering, and calorimeter technologies relevant to EIC detector development.

  • The ERSAP system: ERSAP is being developed at JLab as a backend reactive data-flow system that integrates CODA and the CLARA microservice framework used by CLAS12.Its components are encapsulated into microservices for streaming data acquisition and processing.
  • 11.10.8 A Progressive Approach toward the EIC DAQ System: The envisioned EIC streaming readout reconstructs all events online, adds particle four-vectors and PID information, stores them, and can filter events by selected conditions.Online filtering is intended to accelerate offline analyses by tagging events from channels such as exclusive reactions.
  • 11.10.8 A Progressive Approach toward the EIC DAQ System: Unexpected backgrounds and limited early calibration knowledge require the DAQ to handle noise beyond capacity estimates and to account for initially unavailable detector behavior constants.These conditions are especially relevant during initial EIC operation while the machine is being tuned.
  • 11.10.8 A Progressive Approach toward the EIC DAQ System: The initial EIC strategy is a modular hybrid system that streams detector hits to an online farm and temporarily buffers them before cross-detector zero suppression discards uninteresting data.This approach allows the system to evolve while limiting stored data to portions selected for further processing.
  • 11.10.9 Experimental Validation of the Approach: A realistic triggerless DAQ implementation requires coordinated development and testing of front-end electronics, networks, synchronization, and CPU algorithms against traditional approaches.A dedicated validation program was initiated to identify or develop suitable components and demonstrate expected performance.
  • Thomas Jefferson Laboratory efforts: In 2020, JLab began validating streaming DAQ with FA250+VTP/Waveboard digitizers and TriDAS interfaced with JANA2.The CLAS12 Forward Tagger provided a relevant test case because its luminosity and detector complexity are comparable to conditions anticipated for EIC applications.
  • Thomas Jefferson Laboratory efforts: The CLAS12 beam test used single π0 quasi-real photoproduction to benchmark streaming performance, identifying the π0 through its two Forward Tagger photons while plans expanded streaming to the full detector.A pilot study also routed raw CODA VTP data through ERSAP aggregation, hit finding, noise reduction, event building, and standard CLAS12 reconstruction microservices.
  • Thomas Jefferson Laboratory efforts: Complementary Hall D pair-spectrometer tests measured light yield and energy resolution for glass-ceramic scintillator bars and newly produced PbWO4 crystals using tagged electrons.The prototypes were installed behind the pair spectrometer and their responses were measured in beam.

BNL efforts · The Case for Two Detectors · 640 12.3. MOTIVATION FOR TWO DETECTORS: TECHNOLOGY CONSIDERATIONS

The EIC program combines streaming detector readout and software development with a two-detector strategy that supports complementary coverage, independent cross-checks, and reduced systematic uncertainties. Detector and interaction-region designs therefore emphasize complementary technologies, cross-calibration, and coordinated optimization of the collider’s overall physics output.

  • BNL efforts: Streaming FELIX readout increased the sPHENIX TPC prototype’s event-rate capability by allowing overlapping transmission of data from successive triggers and later reassembly using embedded clock information.The test-beam system also demonstrated simultaneous TPC streaming with beamline instrumentation in classic triggered mode and tested a common timing system.
  • 11.11 Software, Data Analysis and Data Preservation: EIC software planning includes detector-optimization simulations, Monte Carlo generators for polarized e+p, e+D, ^3He, and e+A measurements, full simulation-reconstruction benchmarking, and conventional or AI/ML reconstruction.The Software Consortium and Software Working Group support simulations, infrastructure, and documentation for the Yellow Report and future EIC program.
  • 11.11 Software, Data Analysis and Data Preservation: Streaming operation requires reconstruction software designed to match the readout scheme, while data and analysis preservation is needed to keep detector studies reproducible and documented.Preservation encompasses simulation and reconstruction tools, analysis code, data products, workflows, and detector-development data.
  • 11.12 Artificial Intelligence for the EIC Detector: AI is presented as a means to improve online analysis, tracking, fast detector simulation, and detector-design optimization, including statistically significant performance gains for an automated dual-radiator RICH design study [1615].The report also identifies joint optimization of multiple subdetectors as a high-dimensional combinatorial problem suitable for AI.
  • The Case for Two Detectors: The EIC’s broad physics program and high target luminosities motivate two detectors to address complementary and potentially conflicting acceptance, precision, technology, and interaction-region requirements.The Yellow Report exercise assessed these complementarities and conflicts as a way to expand the physics program and mitigate risks.
  • The Case for Two Detectors: Pairing general-purpose detectors with different physics and technology foci is intended to optimize the collider’s overall output while preserving broad performance across the EIC program.The design premise reflects the unprecedented challenge of maximizing central and forward or backward acceptance in tandem.
  • 12.3.1 Cross Checking: Two independently operated detectors can cross-check potentially groundbreaking results, with different instrumentation technologies reducing the risk of correlated misleading signals.This motivation is explicitly tied to technology choices for the two detectors.
  • 12.3.3 Cross Calibration: Complementary detector designs can minimize systematic uncertainties through cross-calibration, as illustrated by the H1 and ZEUS combination of inclusive DIS data into a legacy measurement [1760].The cited example reports a positive impact on the combined systematic uncertainties.

642 12.3. MOTIVATION FOR TWO DETECTORS: TECHNOLOGY CONSIDERATIONS … GEM and MicroMegas

The EIC’s diverse physics goals and detector constraints motivate two complementary general-purpose detectors, whose technologies and interaction regions can be optimized for different measurements, energies, and cross-checks. Detector R&D has advanced MAPS, GEM, and MicroMegas options, but several technologies still require maturation before construction.

  • 12.4.1 Experimental Solenoid Design: A 3 T field can reduce momentum-resolution uncertainty by approximately a factor of 2 versus 1.5 T, whereas 0.5 T enables charged-particle detection below approximately 0.05 GeV/c.Higher fields benefit momentum resolution, especially at η > 2, while lower fields improve low-pT acceptance; a single detector would otherwise require compromises or time-consuming field changes.
  • 12.4.2 Tracking versus Particle Identification: The central detector must balance tracking and particle identification because a large TPC provides low material and strong PID, while an all-silicon tracker improves compactness, momentum measurement, and vertexing.The MAPS concept has an outer radius of 45 cm rather than 80 cm, but sacrifices particle-identification performance; integrated simulations are still needed for definitive comparisons.
  • 12.4.3 Hermiticity and Acceptance Gaps: Single-detector designs inevitably contain acceptance gaps and dead material, including a gap between beam-line tagging and central calorimetry for scattered electrons in neutral-current DIS.Because scattered-electron angle strongly correlates with Q2, such gaps can affect the accessible kinematic coverage.
  • 12.4.4 Optimization to different centre of mass energies: Two interaction regions can be optimized for different center-of-mass energies, with altered quadrupole placement, crossing angles, secondary focus, beamline instrumentation, detector components, and magnetic fields.This approach allows complementary performance at high and low √s while enabling measurements to be cross-checked.
  • 12.6 Summary; Detector R&D Goals and Accomplishments: Two complementary general-purpose detectors would optimize EIC science by resolving conflicting requirements and independently cross-checking important results.The Yellow Report identifies complementarity from the outset as the preferred design strategy, rather than relying on compromises within one detector.
  • Integrated EIC Detector Concepts; • Electronics racks and data cables; • Power distribution and grounding; • Cooling and gas installation; • Cryogenic capacity; • Shielding against penetrating particles from the machine: The detector concepts require continued integration planning for cabling, power, cooling, gases, cryogenics, shielding, and safety systems across the experimental halls.Service lines and electronics cables must accommodate endcap removal or repositioning, while heat, gas, cryogenic, shielding, and radiation-protection requirements remain to be quantified or coordinated.
  • Detector R&D Goals and Accomplishments; EIC specific R&D: Low-mass & large µRWELL trackers; Low-Mass Forward/Backward GEM Detectors: MAPS R&D targets single-point spatial resolution below 5 µm with very low detector mass, while GEM development supports low-mass tracking and achieved σp/p ≤1.5% for 1.2 < η < 1.7 at 1.5 T.A foil-based Triple-GEM layer contributes 0.6% of X0, allowing up to eight layers within a 5% X0 material budget.
  • GEM and MicroMegas; Generic R&D: Performances and stabilities of µRWELL technology; Hybrid and Gating: MicroMegas offers the best intrinsic ion-backflow suppression and may restore good TPC dE/dx resolution, but stability issues require near-term investigation before pursuing the option.GEM properties and gas choices must be studied to balance ion-backflow suppression against dE/dx performance; EIC-TPC ion backflow estimates remain configuration-dependent.

Readout Electronics … SATURDAY, 21 NOVEMBER

The report develops EIC detector technologies spanning particle identification, fast timing, calorimetry, tracking, photon detection, and data acquisition, while identifying performance targets and remaining engineering risks. Across these systems, prototypes and simulations demonstrate promising capabilities, but photosensor, ASIC, radiation, integration, and operating-condition R&D remain essential.

  • 14.3.2 A Dual-Radiator Ring Imaging Cherenkov Detector (dRICH): dRICH provides π/K/p separation better than 3σ from ∼3 to ∼60 GeV/c and e/π separation from a few hundred MeV to about 15 GeV/c, making it a day-1 PID detector.Its baseline covers ∼5–25° (pseudorapidity ∼1.5–3) using aerogel and gas radiators with highly segmented photosensors.
  • 14.3.3 High-Performance DIRC: The hpDIRC targets π/K separation of at least 3σ up to 6 GeV/c in the barrel, within a compact system thinner than 8 cm that requires no cryogenic cooling or flammable gases.Its remaining work includes matching the final detector layout, optimizing cost, validating a full prototype, and developing suitable small-pixel MCP-PMT or LAPPD readout.
  • 14.3.4 Photosensor: MCP-PMT and LAPPD: Argonne MCP-PMT/LAPPD development demonstrated gain of 10^6–10^7, ∼80 ps RMS timing, ∼20 ps single-photoelectron timing, magnetic-field tolerance above 1.5 T, and position resolution below 1 mm with 3×3 mm2 pixels.These photosensors address the need for high-performance, lower-cost coverage across EIC Cherenkov and time-of-flight systems, although further validation and beam tests are required.
  • 14.3.5 R&D Needs for GEM-TRD/Tracker in the Forward Direction: Forward electron identification may require a high-granularity tracker plus GEM-TRD to add pion rejection of 10–100, while hadronic calorimetry must be optimized differently for forward endcaps and barrel regions.GEM-TRD development focuses on low-mass radiators, specialized field cages, lower-cost large-pad readout, high-voltage optimization, and Xe-gas recirculation.
  • 14.3.6 Gaseous Single Photon Detectors Based on MPGD Technologies: Gaseous photon detectors remain attractive for large-area, low-material-budget, high-field RICH systems, while hydrogenated nanodiamond is being explored as a more robust alternative to chemically fragile CsI.The novel photoconverter requires longer maturation and may be selected according to its maturity when the detector design is finalized.
  • 14.3.7 Fast Timing Silicon Sensor: LGADs: LGADs offer compact tracking with simultaneous TOF-PID, strong-field tolerance up to ∼4 T, radiation tolerance to ∼2 × 10^15 neq/cm2, and 14 ps timing from three stacked 35 µm layers.The demonstrated timing result supports multilayer fast-timing systems integrated into EIC tracking.
  • 14.4.2 SciGlass for Electromagnetic Calorimetry: SciGlass aims to provide cheaper, faster, and more flexible radiation-hard electromagnetic calorimetry, with simulations and 4–5 GeV beam tests indicating resolution competitive with PbWO4 for thicknesses above 15X0.Samples reach ∼10 radiation lengths, with no observed damage up to 1000 Gy electromagnetic and 10^15 n/cm2 hadron irradiation, plus 20–50 ns response time.
  • Readout Electronics: EIC readout is expected to use streaming acquisition and precision timing distribution, but front-end ASIC coverage, unpredictable initial backgrounds and rates, and material-heavy TPC electronics remain significant implementation risks.Developing entirely new ASICs may take six or more years, while timing systems must distribute precise clocks and calibrate environmental phase drift.
Loading 2103.05419v3…