# APCTP Workshop on the Physics of Electron Ion Collider

Asia/Seoul
Howard Johnson Incheon Airport Hotel

#### Howard Johnson Incheon Airport Hotel

6 Shindosinam-ro 142bungil, Jung-gu, Incheon, 22371, Korea Tel: 032-722-0000 http://howardjohnsonincheon.com/en/
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Description

The Electron-Ion Collider (EIC), planned to be built at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory (BNL), in partnership with Thomas Jefferson National Accelerator Facility (Jefferson Lab), will be the most advanced tool for studying some of the deepest unexplored recesses of the atom.

The EIC will be a particle accelerator that collides electrons with protons and nuclei to produce snapshots of those particles’ internal structure—like a CT scanner for atoms. The electron beam will reveal the arrangement of the quarks and gluons that make up the protons and neutrons of nuclei. The force that holds quarks together, carried by the gluons, is the strongest force in Nature. The EIC will allow us to study this “strong nuclear force” and the role of gluons in the matter within and all around us. What we learn from the EIC could power the technologies of tomorrow.  Topics for this workshop could also include topics in heavy-ion physics, high-energy physics, and any other physics that might have connections to the EIC and its detector and accelerator technologies. We will also discuss international collaborations, especially in Asian Pacific countries.

This is an in-person meeting. We do not provide a service for online participation of audience.

Asia Pacific Center for Theoretical Physics

Participants
• Abhay Deshpande
• Chang-Seong Moon
• Christopher Dilks
• Dong Ho Moon
• Ernst Sichtermann
• Francesco Bossu
• Hungchong Kim
• Hwidong Yoo
• Hyeon-Dong Son
• Hyon-Suk Jo
• Hyun-Chul Kim
• Jae Hyeok Yoo
• Jeongsu Bok
• Jim Yeck
• Jin-Hee Yoon
• Kirill Semenov-Tyan-Shanskiy
• Kyungseon JOO
• Ming Liu
• MinJung Kweon
• Or Hen
• Paweł Sznajder
• Ralf Seidl
• Rolf Ent
• Saehanseul Oh
• Sanghoon Lim
• Sangyeong Son
• Satoshi Yano
• Sehwook Lee
• Shuddha Shankar Dasgupta
• Shunzo Kumano
• Su Houng Lee
• Sungtae Cho
• Taeksu Shin
• Timothy Hallman
• Wenliang Li
• Yi Yang
• Yongseok Oh
• Yongsun Kim
• Yongwoo Choi
• Youngil Kwon
• Yuji Goto
• Yunkyu Bang
• Zein-Eddine Meziani
• Wednesday, November 2
• 8:00 AM 8:50 AM
Registration
• 8:50 AM 10:45 AM
Session: 1
Convener: Yongseok Oh (Kyungpook National University)
• 8:50 AM
Welcome and Opening Remarks 10m

Welcome and opening remarks by the president of APCTP

Speaker: Yunkyu Bang (Asia Pacific Center for Theoretical Physics)
• 9:00 AM
Science and Opportunities at the Electron Ion Collider 35m

The Electron Ion Collider (EIC) will be built at Brookhaven National Laboratory (BNL) in partnership with Jefferson Laboratory. With its high luminosity, polarized electron and light ion beams and its ability to bring any nucleus from protons to Uranium in collisions with electrons at various center of mass energies, it will arguably be the most versatile and powerful accelerator facility ever built for fundamental science. Equally innovative and powerful detectors - well integrated with the machine - are planned to extract the science from the collisions. In this talk, I will summarize the science of EIC, the state of its detector planning and speculate on future opportunities for novel scientific explorations (and collaborations).

Speaker: Abhay Deshpande (Stony Brook University)
• 9:35 AM
Electron-Ion Collider Progress and Plans 35m

An overview of the progress preparing the Electron-Ion Collider (EIC) for construction. The presentation addresses the EIC design requirements, conceptual design, and construction schedule. Current efforts to promote international engagement and collaboration will be described, including opportunities for contributions to the design and construction of the accelerators and collaboration on the experimental program.

Speaker: James Yeck (Brookhaven National Laboratory)
• 10:10 AM
Perspectives from DOE NP 35m
Speaker: TImothy J. Hallman (DOE of the USA)
• 10:45 AM 11:15 AM
Break 30m
• 11:15 AM 12:25 PM
Session: 2
Convener: Kyungseon Joo (University of Connecticut)
• 11:15 AM
The Quest to Understand the Fundamental Structure of Matter – Outlook to QCD and the Electron-Ion Collider Detector 35m
Speaker: Rolf Ent (Jefferson Lab.)
• 11:50 AM
Prospective for Korean Contribution for EIC 35m

The electron ion collider (EIC) is the next generation collider that collides electrons with protons and nuclei to study the internal structure of particles and exotic matter with unprecedented precision. Given to be built at Brookhaven National Laboratory, an active discussion is ongoing for developing detectors worldwide. In this presentation, we will report on Korean groups' current status in preparation for detector development.

Speaker: Yongsun Kim (Sejong University)
• 12:25 PM 2:00 PM
Lunch 1h 35m
• 2:00 PM 3:45 PM
Session: 3
Convener: Yongsun Kim (Sejong University)
• 2:00 PM
Activities of the EIC Japan Group 35m

EIC is the world's first electron-ion collider. A polarized electron beam is collided with a polarized proton, polarized light ion, or heavy ion beam with high energy and luminosity to perform precise experiments on QCD. We have formed the EIC Japan Group to bring together those who wish to participate in the EIC project in order to prepare for Japanese researchers to participate in the EIC. In this talk, we would like to discuss the Zero-Degree Calorimeter (ZDC) and other detectors, which the EIC Japan group is interested in as detectors for EIC, and the physics that can be obtained by EIC using them. We also will describe what kind of efforts have been made and will be made in Japan for EIC, and give our thoughts on what kind of cooperation we would like to have between Korea and Japan.

Speaker: Yuji Goto (RIKEN)
• 2:35 PM
Partonic Structure of Nucleon and Nuclei at an EIC; Argonne Activities 35m

I will discuss the partonic structure of the proton and nuclei at an EIC with an emphasis on the gluonic gravitational form factors. Then present the experimental activities of the Argonne medium energy group to address the above science at an EIC. It comprises a proposed barrel imaging electromagnetic calorimeter for the ePIC detector, the development of a polarized Li6 ion beam, the development of superconducting nanowire detectors for tagging recoil nuclei in the far-forward region, and an additive manufacturing technology for MCP-photosensors fabrication needed in Ring Imaging Cherenkovs under magnetic fields, and Software/Computing kits for analysis in synergy with a recently approved SciDAQ proposal in collaboration with the theory group at Argonne.

Speaker: Zein-Eddine Meziani (Argonne National Laboratory)
• 3:10 PM
Development of MIP Timing Detector for the CMS Phase-2 Upgrade 35m

The Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) will undergo extensive Phase-2 upgrades during the long shutdown 3 (LS3) scheduled to prepare for the challenging conditions of the High-Luminosity LHC (HL-LHC). One of the most prominent aspects of the upgrade will be the introduction of a new detector sub-system, the MIP Timing Detector (MTD), situated between the outer tracker and the electromagnetic calorimeter. A new CMS timing detector will measure minimum ionizing particles (MIPs) with a time resolution of ~30-40 ps. The precision time information from this MIP timing detector (MTD) will significantly reduce the effect of pileup at the HL-LHC, bringing new capabilities to the CMS detector. The MTD will be composed of an endcap timing layer (ETL), instrumented with low-gain avalanche diodes (LGAD), as well as a barrel timing layer (BTL), based on LYSO:Ce crystals coupled to SiPMs. In this talk, we present an overview of the MTD design, describe the latest progress on prototyping and production as well as test beam results. In addition, we discuss the possible application of LGAD sensors at the EIC.

Speaker: Chang-Seong Moon (Kyungpook National University (KR))
• 3:45 PM 4:15 PM
Break 30m
• 4:15 PM 6:00 PM
Session: 4
Convener: Ralf Seidl (RIKEN)
• 4:15 PM
Activities of Korean Physics Community for EIC 35m

In this talk, I summarize the efforts of the Korean Physics Community, in particular, in nuclear and hadron physics, to contribute to the EIC project. I review the previous efforts at the beginning period of the EIC project and introduce the activities of the Korean community in the physics of EIC. This includes the introduction to APCTP and its support for the Korean community's efforts for EIC.

Speaker: Yongseok Oh (Kyungpook National University)
• 4:50 PM
Prospects on GPDs and Structure Functions of Spin-1 Deuteron 35m

Masses and spins of hadrons are fundamental quantities in physics; however, their origins are not understood yet and their investigations are major purposes of building electron-ion colliders for physics in 2030's. Both of them can be investigated by generalized parton distributions (GPDs). The spacelike (timelike) GPDs are studied by deeply virtual Compton scattering (two-photon processes) at charged-lepton accelerator facilities ($e^+ e^-$ collider facilities) such as the JLab, CERN-AMBER, and EICs (KEKB). Since the GPD studies by the charged-lepton scattering should be covered by other speakers, I discuss other experimental prospects at the $e^+ e^-$ collider KEKB, the hadron-accelerator facility J-PARC, and the Long-Baseline Neutrino Facility (LBNF) at Fermilab. It is possible to extract the timelike GPDs and gravitational form factors of hadrons by the two-photon processes $\gamma^* + \gamma \to h + \bar h$, where $h$ is a hadron. Actually, there was the first report on the determination of the gravitational form factors and radii (mass and mechanical radii were 0.32-0.39 fm and 0.82-0.88 fm for $\pi^0$) from actual experimental measurements in Ref.[1]. At J-PARC, the GPDs will be investigated by the exclusive Drell-Yan process $\pi^- p \to \mu^+ \mu^- B$ [2], where the baryon $B$ could be a nucleon or $\Delta$. In future, other processes could be investigated for the GPDs. For example, the $2 \to 3$ reaction processes $NN \to N \pi B$ could be used for probing the GPDs in the ERBL (Efremov-Radyushkin-Brodsky-Lepage) region [3]. In addition, the neutrino facility Fermilab-LBNF can be used for the GPD measurement by the single-pion production processes $\nu + N \to \ell^- + N' + \pi$ and $\bar\nu + N \to \ell^+ + N' + \pi$ [4].

There was recent theoretical progress on transverse-momentum-dependent parton distribution functions (TMDs) and parton distribution functions (PDFs) for spin-1 hadrons, such as the deuteron, at twists 3 and 4 [5]. We showed that 30 new structure functions and also new fragmentation functions exist at twists 3 and 4. Integrating the TMDs over the transverse momentum, we found new collinear PDFs. Then, we derived a twist-2 relation and a sum rule for the tensor-polarized PDFs $f_{1LL}$ and $f_{LT}$, and we also showed that twist-3 multiparton distribution functions $F_{LT}$, $G_{LT}$, $H_{LL}^\perp$, and $H_{TT}$ exist. Relations among these collinear parton- and multiparton-distribution functions were derived by using the equation of motion for quarks. These studies will be useful in future investigations on the spin-1 structure functions. We expect that the field of structure functions for spin-1 hadrons will become a hot topic in the near future because of experimental projects at the JLab, the Fermilab, the NICA, the LHCspin, and the electron-ion colliders in US and China.

References
[1] S. Kumano, Qin-Tao Song, and O. V. Teryaev, Phys. Rev. D 97, 014020 (2018).
[2] T. Sawada et al., Phys. Rev. D 93, 114034 (2016); J-K. Ahn et al., Letter of Intent for J-PARC, LoI_2019-07; Wen-Chen Chang et al., J-PARC proposal under preparation.
[3] S. Kumano, M. Strikman, and K. Sudoh, Phys. Rev. D 80, 074003 (2009).
[4] S. Kumano and R. Petti, Proc. of Science, NuFact2021, 092 (2022).
[5] S. Kumano and Qin-Tao Song, Phys. Rev. D 103 (2021) 014025; JHEP 09 (2021) 141; Phys. Lett. B 826 (2022) 136908.

Speaker: Shunzo Kumano (Japan Women's University / KEK)
• 5:25 PM
Mechanical Properties of the Baryon Octet and Singly Heavy Baryons 35m

In the present talk, we review recent work on the gravitational form factors (GFFs) and the energy-momentum tensor (EMT) distributions of the baryon octet. Based on the SU(3) chiral quark-soliton model, we first examine the effects of flavor SU(3) symmetry breaking on the GFFs. We observe that a heavier hyperon is energetically more compact than a lighter one. We also show that the spin distribution of the octet baryon can be decomposed into the quark components (singlet axial charges) and the quark angular momentum ones. We discuss the pressure and shear-force densities in three dimensional Breit frame. Then, we bring them to the infinite momentum frame (IMF) by implementing the IMF Abel transformation. Finally, we present the results for the EMT distributions of the singly heavy baryons and discuss their physical implications.

Speaker: Hyun-Chul Kim (Inha University)
• 6:30 PM 7:30 PM
Dinner 1h
• Thursday, November 3
• 9:00 AM 10:45 AM
Session: 5
Convener: Abhay Deshpande (Stony Brook University)
• 9:00 AM
The ePIC experiment at the EIC: Status and Opportunities 35m
Speaker: Or Hen (Massachusetts Institute of Technology)
• 9:35 AM
EIC, the Ultimate Machine for Hadron Physics. A CEA’s Perspective 35m

Among the broad spectrum of activities of the Institute for research into the fundamental laws of the Universe (Irfu) of CEA, nuclear physics plays an important role. CEA is strongly involved in the study of the inner structure of protons and neutrons, both in phenomenology and in experiments. In particular, CEA has been playing leading roles in JLab experiments as well as in COMPASS at CERN. Since 2011, CEA has been been working on defining the physics case for the Electron Ion Collider (EIC), which is currently part of CEA’s roadmap for future decades. An overview of the CEA’s interests and involvement in EIC will be presented.

Speaker: Francesco Bossù (CEA/Irfu)
• 10:10 AM
Taiwanese Involvement in EIC 35m

Electron-Ion Collider (EIC) is one of the most important scientific programs in nuclear and high energy physics disciplines in the coming future. Taiwanese institutions have been deeply involved in both detector developments and physics analyses in many territories, including RHIC, LHC, and other experiments on fixed target physics, heavy-ion physics, and (Beyond) Standard Model physics. Therefore, we are enthusiastic to contribute to the EIC program and collaborate with our Asian colleagues. In this talk, I will present the involvement in EIC from Taiwanese institutions, including the developments of DC-LGAD sensors, mechanical structure for the TOF detector, and Optical readout system, as well as our physics interests. I will also introduce the capabilities of our new facility in Taiwan, called Taiwan Instrumentation And Detector Consortium (TIDC).

Speaker: Yi Yang (National Cheng Kung University)
• 10:45 AM 11:15 AM
Lunch 30m
• 11:15 AM 12:25 PM
Session: 6
Convener: Yuji Goto (BNL)
• 11:15 AM
Silicon Tracking for E(P)IC 35m
Speaker: Ernst Sichtermann (Lawrence Berkeley National Laboratory)
• 11:50 AM
ITS3 for ALICE 35m

A new inner tracking system (ITS2) with monolithic active silicon pixel sensors has been successfully installed and is operated for the ALICE experiment at Run 3. For further improvement of the inner layers of the tracking system (ITS3), wafer-scale bent pixel sensors are under development based on the flexibility of the silicon sensor of about 30 µm thickness. The wafer-scale sensor can be produced using the stitching technique. In addition, the material budget will be significantly reduced by cooling with airflow and supporting with carbon form so that the pointing resolution will be improved. This upgrade will help new measurements of heavy-flavor hadrons and electromagnetic probes. In this talk, we will report on the status of sensor development, performance tests of bent sensors, and other studies.

Speaker: Sanghoon Lim (Pusan National University)
• 12:25 PM 2:00 PM
Lunch 1h 35m
• 2:00 PM 3:45 PM
Session: 7
Convener: Zein-Eddine Meziani (Argonne National Laboratory)
• 2:00 PM
Interest in AC-LGAD development of EIC-Japan 35m

Speaker: Satoshi Yano (Hiroshima University)
• 2:35 PM
Recent Results of CMS LGAD Sensor Testing 35m

As part of the CMS Phase 2 upgrade, MIP Timing Detector is planned to be installed in order to mitigate the impact of pileup that is expected to reach 200 in HL-LHC. Due to the difference in the radiation environment, different technologies are used for the barrel and the endcap regions. Low Gain Avalanche Diode (LGAD) sensors are used in the endcap region due to their radiation-hardness. Prototype sensors have been produced and tested to optimize the sensor design. In this talk, some highlights of the recent testing results will be presented.

Speaker: Jae Hyeok Yoo (Korea University)
• 3:10 PM
The Dual-Readout Calorimeter R&D for Future Colliders in Korea 35m

The dual-readout calorimeter (DRC) is one of calorimeter candidates to achieve very high energy resolutions for both EM and hadronic particles in future colliders such as FCC-ee and CEPC. Korea DRC collaboration has studied various aspects of the DRC R&D and performed the test-beam experiment with two prototype modules at CERN in the last August. In this talk, we present the recent progress of the DRC R&D for future colliders in Korea.

Speaker: Hwidong Yoo (Yonsei University)
• 3:45 PM 4:15 PM
Break 30m
• 4:15 PM 5:25 PM
Session: 8
Convener: Hyun-Chul Kim (Inha University)
• 4:15 PM
Getting to Grips with GPD Extraction 35m

I will present recent advancements in the field of GPD phenomenology. This includes, but is not limited to, work on a better understanding of model biases spoiling the extraction of GPD information. New elements of impact studies supporting future experimental programmes will be presented as well.

Speaker: Paweł Sznajder (National Centre for Nuclear Research, Poland)
• 4:50 PM
Backward Angle (u-channel) Processes at EIC 35m

The recent measurements on exclusive backward-angle electroproduction of meson from Jefferson Lab electron-proton fixed-target scattering experiments above the resonance region, hint at a new domain of applicability of QCD factorization in a unique u-channel kinematics regime, known as the nucleon-meson Transition Distribution Amplitude (TDA). Thanks to these pioneering efforts, the interest in studying nucleon structure through u-channel meson production observables has grown significantly. In this presentation, we will explore the u-channel observables from JLab 12 GeV program to the future Electron-Ion Colliders EIC. Hence, to further validate and study the TDA framework to uncover the unexplored characteristics of the nucleon wave function.

Speaker: Wenliang Li (Stony Brook University)
• 6:30 PM 7:30 PM
Dinner 1h
• Friday, November 4
• 9:00 AM 10:45 AM
Session: 9
Convener: Sanghoon Lim (Pusan National University)
• 9:00 AM
Heavy Flavor Physics with the sPHENIX MVTX Vertex Tracker Upgrade and Opportunity for the Future EIC R&D 35m

The sPHENIX detector currently under construction at the Relativistic Heavy Ion Collider (RHIC) at BNL will measure a suite of unique jet, open heavy flavor and Upsilon observables with unprecedented statistics and kinematic reach at RHIC energies. A MAPS-based silicon pixel VerTeX detector upgrade to sPHENIX, the MVTX, will provide a precise determination of the impact parameter of tracks relative to the primary vertex in high multiplicity heavy ion collisions. The MVTX utilizes the latest generation of MAPS technology to provide precision tracking with high efficiency over a broad momentum range in the high luminosity p+p, p+Au and Au+Au collisions at RHIC. These new capabilities will enable precision measurements of open heavy flavor observables, covering an unexplored kinematic regime at RHIC, and shed new light to our understanding of heavy flavor production and interactions with nuclear medium in transversely polarized p+p and p+A collisions. The physics program, its potential impacts, and recent detector development of the MVTX and opportunity for the future EIC experiment with heavy flavor probes will be discussed in this talk.

Speaker: Ming Liu (Los Alamos National Laboratory)
• 9:35 AM
Advanced Si Sensors, What Has Been Done and Can Be Done By Korea 35m

Korea has a strong industrial backgrounds in the Si device processing, which has been utilized for the ITS upgrade project of the ALICE experiment. ALPIDE is the monolithic active pixel sensor, an advanced form of the Si sensor, for the project. The sensor was fabricated by the advanced Si device processing technology, and Korean involvements in the effort includes a broad spectrum, the post-processing and production test of the sensors, and the detector module assembly. We review specifics of what has been done and discuss open chances Korean industry might offer.

Speaker: Youngil Kwon (Yonsei University (KR))
• 10:10 AM
The Status and Overview of RAON 35m

RAON is the flagship rare isotope accelerator and science facility in Korea. After the blessing of the Korean government's announcement for the construction of a rare isotope accelerator in 2009, the construction of RAON was launched in 2011 by the Rare Isotope Science Project (RISP) under Institute for Basic Science (IBS) to aim for a large scale basic science research facility. RAON was designed to produce a variety of stable and rare isotope beams to be used for research in basic science and various applications. RAON consists of a heavy ion superconducting linear accelerator (linac) as the driver of IF (In-flight Fragmentation) system and a proton cyclotron as the driver for the ISOL (Isotope Separation On-Line) system and a superconducting post-accelerator linac for the ISOL system. The ISOL and IF systems can be operated independently. In addition, the rare isotopes produced by the ISOL system can be injected into the superconducting linac SCL3 for further acceleration to higher energies to produce even more exotic rare isotopes. This combined scheme of the ISOL and IF may be referred to as ISOLIF. The construction of buildings and supporting facilities of RAON is finished and developments of major instruments for superconducting linear accelerators, cryo-plant systems, ISOL facility with Cyclotron, experimental facilities, and the post-accelerator superconducting linear accelerator (SCL3) are mostly done. Recently, the first phase of the SCL3 beam commissioning experiment using the Argon beam from the RAON injector system was carried out successfully. ISOL facility with a 70 MeV proton cyclotron, and low-energy experimental facilities such as KoBRA (Korea Broad acceptance Recoil Spectrometer and Apparatus) are also prepared for beam commissioning. Here, we report on the overview and current status of the RAON heavy ion accelerator facility.

Speaker: Taeksu Shin (IBS)
• 10:45 AM 11:15 AM
Break 30m
• 11:15 AM 12:25 PM
Session: 10
Convener: Or Hen (Massachusetts Institute of Technology)
• 11:15 AM
Possible Indian Participation at EPIC collaboration in EIC 35m

The proposed new Electron-Ion collider poses a technical and intellectual challenge for the detector design to accommodate the long-term diverse physics goals envisaged by the program; one requires a 4𝝅 detector system capable of identifying and reconstructing the energy and momentum of final state particles with high precision. The EPIC collaboration has formed to design, build, and take data with Detector 1. India has been involved in high-energy physics experiments around the world including ALICE, and CMS experiments in LHC at CERN, and in the STAR experiment at Brookhaven National Laboratory, the USA among many others. A large community already doing intensive phenomenological studies, physics analysis, and simulations regarding QCD physics is interested in participating in EIC. India has been doing R&D on detector technologies like Resistive Plate Chambers (RPCs), Gas Electron Multipliers (GEMs), Thick GEMs and Micromegas, etc., for the last several years. Regarding EIC hardware activities, India is willing to participate in Particle Identification (PID), Tracking, and DAQ development. Several groups have shown interest in tracking detector development based on Micro Pattern Gaseous Detector (MPGD) technologies and Silicon Detector Technologies. Some groups are solely interested in participating in PID hardware activities. A broad overview of possible Indian participation in ePIC hardware activities along with related software activities will be presented in the talk.

Speaker: Shuddha Shankar Dasgupta (National Institute of Science Education and Research, India)
• 11:50 AM
A Next-Generation Heavy-Ion Experiment for the LHC: ALICE 3 35m

ALICE3 is proposed as the next-generation experiment for LHC Run 5 to address unresolved questions that cannot be answered fully with the present or currently planned detectors. Some key measurements will be the precise measurements of heavy-flavour probes, charmed exotic states, high-precision measurements of electromagnetic radiation, and chiral-symmetry restoration. To pursue this physics program, a concept of a novel detector with a high read-out rate, superb pointing resolution, and excellent tracking and particle identification over a large acceptance is being developed using advanced silicon detectors. It is being developed that concept of a high-resolution vertex tracker inside the beam pipe to achieve the best pointing resolution, which is surrounded by a silicon-pixel tracker covering about eight units of pseudo-rapidity. A combination of a time-of-flight system based on the silicon sensor and a Ring-Imaging Cherenkov detector is foreseen to achieve the particle identification performance required. Further detectors, such as an electromagnetic calorimeter, and a muon identifier, are being studied. This presentation will explain the detector concept and its physics reach and discuss the R&D challenges.

Speaker: MinJung Kweon (Inha University)
• 12:25 PM 2:00 PM
Lunch 1h 35m
• 2:00 PM 3:45 PM
Session: 11
Convener: Paweł Sznajder (National Centre for Nuclear Research, Poland)
• 2:00 PM
TMDs with Single Hadron Production at the EIC 35m

One of the main goals of the EIC is the understanding of the transverse spin and momentum structure of the nucleon. For such measurements, typically semi-inclusive processes are required where in addition to the scattered lepton kinematics, also at least a final-state hadron is detected. The hadron provides additional flavor sensitivity and the transverse momentum relative to the virtual photon allows to disentangle various contributions such as the quark transversity together with the Collins fragmentation or the Sivers effect. The EIC Yellow report and the subsequent detector proposals have highlighted the physics interest and detector requirements for such TMD measurements. These measurements, the requirements and the anticipated impact of the EIC will be presented.

Speaker: Ralf Seidl (RIKEN)
• 2:35 PM
TMDs with Dihadrons and Lambdas at the EIC 35m

Measurements in semi-inclusive deep inelastic scattering provide a wide range of insights into nucleon structure and hadronization. Spin asymmetries and cross sections in single-hadron and dihadron production are sensitive to various combinations of transverse momentum-dependent (TMD) distribution and fragmentation functions, depending on the polarizations of the initial electron and target nucleon. For example, at leading twist the asymmetry $A_{UT}$ in dihadrons accesses the Sivers, transversity, pretzelosity, and Kotzinian-Mulders TMD distributions. These TMDs are coupled to dihadron fragmentation functions, which offer insight into correlations of the spin of the fragmenting parton with the angular momentum of the outgoing dihadron. Furthermore, TMD fragmentation functions are accessible via the production of a final state with a known polarization, in particular, lambdas. These functions probe spin-orbit correlations in fragmentation analogously to those in TMD PDFs. This presentation will summarize the possibilities of these measurements at the future Electron-Ion Collider.

Speaker: Christopher Dilks (Duke University)
• 3:10 PM
Hard Exclusive Reactions with Baryon Number Transfer and Transition Distribution Amplitudes 35m

Nucleon-to-meson Transition Distribution Amplitudes (TDAs) appear as building blocks in the collinear factorized description of amplitudes for a class of hard exclusive reactions prominent examples being hard exclusive pion electroproduction off a nucleon in the backward region and baryon-antibaryon annihilation into pion and a lepton pair. We discuss general properties of nucleon-to-meson TDAs and argue that these non-perturbative objects turn to be a convenient complementary tool to explore the structure of hadrons at the partonic level. We present an overview of hard exclusive reactions admitting a description in terms of TDAs. We discuss the first signals from hard exclusive backward meson electroproduction at JLab and explore further experimental opportunities to access TDAs at JLab, PANDA, J-PARC and EIC.

Speaker: Kirill Semenov-Tyan-Shanskiy (Kyungpook National University)
• 3:45 PM 4:15 PM
Break 30m
• 4:15 PM 5:25 PM
Session: 12
Convener: Kyungseon Joo (University of Connecticut)
• 4:15 PM
Round Table Discussion - K-EIC Path Forward 1h
• 6:30 PM 7:30 PM
Dinner 1h