EINN2025

27 Oct 2025, 09:00 → 1 Nov 2025, 21:45 Europe/Athens

Monday 27 October

18:00 → 21:00 Welcome reception in Coral Beach Hotel & Resort hotel: Christian Bernard Hall & Aphrodite Terrace

Christian Bernard Hall

18:00 The cultural heritage of Cyprus

Speaker: Stathis Raptou

18:30 Celebration of 30 years EINN - Reception

Speakers: Marc Vanderhaeghen (Johannes Gutenberg University of Mainz), Zein-Eddine Meziani (Argonne National Laboratory)

Tuesday 28 October

08:00 → 09:00 Registration

09:00 → 10:30 Conference Talks: Christian Bernard Hall

Convener: Martha Constantinou (Temple University)

09:00 Opening

Speaker: Martha Constantinou (Temple University)

09:10 Studying hadrons and nuclei with electromagnetic processes: Experimental overview

Electromagnetic processes are essential and versatile tools in studying myriad aspects of hadronic and nuclear physics. This talk will offer a tour of the various ways in which electromagnetic processes and probes are used to inform our understanding of hadron structure, hadronization mechanisms, what partonic bound states exist, and properties of extreme nuclear matter. We’ll also consider how electromagnetic interactions in comparison to hadron-hadron interactions can shed light on questions of universality and unique features of QCD due specifically to its non-Abelian nature.

Speaker: Christine Aidala

AidalaEINN2025.pdf

09:50 Theoretical Perspectives on Electromagnetic Hadronic Physics

I’ll give my personal perspective on a general overview of the most recent and relevant theoretical developments about how we picture the internal structure of hadrons.

Speaker: Marco Radici (Istituto Nazionale di Fisica Nucleare)

radici_print.pdf

10:30 → 11:00 Coffee break

11:00 → 12:30 Conference Talks: Christian Bernard Hall

Convener: Marc Vanderhaeghen (Johannes Gutenberg University of Mainz)

11:00 Current view on the muon g-2

Speaker: Fred Jegerlehner (DESY Zeuthen)

11:30 What’s next for the theory of muon g-2?

The anomalous magnetic moments of the muon and the electron, 𝑎μ and 𝑎ₑ, are precision benchmarks of the Standard Model and promising New-Physics probes. The hadronic vacuum polarization (HVP) contribution remains the dominant source of uncertainty, a problem compounded by the current tension between data-driven (dispersive) and lattice QCD evaluations. I will discuss the status of the HVP contribution, contrasting the two approaches and highlighting recent progress in understanding isospin-breaking effects. The subleading hadronic light-by-light (HLbL) contribution still leaves considerable room for improvement. Looking further ahead, the electron 𝑔−2, once the fine-structure constant αₑₘ is known with greater precision, may provide an additional stringent constraint on hadronic contributions. These developments chart the path toward reducing theoretical uncertainties to the level of the completed Fermilab measurement of the muon 𝑔−2.

Speaker: Vladimir Pascalutsa

Pascalutsa_whatsnext_EINN_Oct28_2025.pdf

12:00 Muon g-2, from Anomaly to Agreement: The HVP contribution from Lattice QCD

The anomalous magnetic moment of the muon, $a_\mu$, remains a benchmark precision test of the Standard Model. The long-standing tension between experiment and theory has driven major progress in recent years, culminating in the latest White Paper, which incorporates state-of-the-art lattice QCD determinations of the hadronic vacuum polarization (HVP). These first-principles results, obtained independently by several collaborations, have brought the Standard Model prediction into close agreement with experiment and reshaped the theoretical landscape. Beyond $a_\mu$, the same HVP contributions underpin a broader set of precision quantities—including the $R$-ratio and Euclidean “window” observables—that enable direct, model-independent comparisons between lattice and dispersive approaches. This talk will review the current status of these HVP-related quantities, highlight the collective lattice effort driving these advances, and discuss the emerging picture from cross-method comparisons and their implications for precision tests of the Standard Model.

Speaker: Simone Bacchio

EINN_MuonHVP_LatticeQCD_Bacchio.pdf

12:30 → 15:00 Lunch Break

15:00 → 16:40 Parallel Workshop 1: Christian Bernard Hall

Christian Bernard Hall

15:00 Electromagnetic Form Factors of the Nucleon with Dispersively Improved Chiral Effective Field Theory

In this talk, I will show how effective field theory can be combined with dispersion theory to provide a representation of the nucleon's electromagnetic form factors that incorporates the correct analytical structure and the dynamics of QCD at low energy. As an application, I will present how this approach contributes to the determination of the proton's charge and magnetic radii, as well as its predictions for the MUSE experiment.

Speaker: Prof. Jose Manuel Alarcon (University of Alcalá)

Alarcon_EINN2025.pdf

15:25 Nucleon electromagnetic and weak form factors

Nucleon electroweak form factors contain relevant details about hadronic structure and strong interactions in the nonperturbative regime. This information is encoded in their dependence on the momentum transferred to the nucleon by external probes but also in their quark-mass dependence, which is accessible by Lattice QCD (LQCD) simulations.

In our study we rely on relativistic chiral perturbation theory (ChPT) in two flavors with explicit Delta(1232) degrees of freedom. For the electromagnetic isovector form factors we also employ dispersion theory to account for rho-dominated isovector pion-pion interaction and its quark-mass dependence in the t-channel nonperturbatively and beyond NLO in ChPT. With this framework we explore how LQCD data are described in both the Q2 and mpi dimensions simultaneously. Furthermore, we have performed an NNLO calculation of the nucleon axial form factor, extracting relevant low-energy constants from a combined set of recent LQCD results from different collaborations.

Speaker: Fernando Alvarado (GSI)

main.pdf

15:50 Chiral symmetry and nuclear interactions

Chiral effective field theory has become a standard tool to analyze low-energy reactions involving pions, nucleons and external electroweak sources. I will briefly describe conceptual foundations of this method, review our recent efforts towards developing it into a precision tool for low-energy nuclear physics and discuss some of the remaining challenges.

Speaker: Evgeny Epelbaum

Talk_EINN2025_EE.pdf

16:15 Dispersive analysis of two photon reactions

We perform a coupled-channel dispersive analysis of $γ^{(∗)}γ^{(∗)} \to \pi\pi/\pi\eta/K\bar{K}$ using a modified Muskhelishvili–Omnès framework that enforces analyticity and unitarity, modeling the left-hand cut with pion/kaon and vector-meson pole terms. Both unsubtracted and subtracted forms are studied, the latter incorporating Adler-zero constraints. The S-wave $\pi\pi/K\bar{K}_{I = 0}$ and $\pi\eta/K\bar{K}_{I=1}$ channels describe the $f_0(500)$, $f_0(980)$, and $a_0(980)$, while the D-wave is anchored by the $f_2(1270)$ and $a_2(1320)$ resonances. As an application to $(g − 2)_\mu$, we obtain dispersive HLbL rescattering estimates from scalar channels with improved precision over narrow-width models. A new two-photon Monte Carlo generator in development at Mainz will also be briefly presented.

Speaker: Igor Danilkin (Johannes Gutenberg University of Mainz)

Danilkin2025_EINN.pdf

15:00 → 16:40 Parallel Workshop 2: Aphrodite Room

15:00 Advances in AI/ML for theoretical nuclear physics

The rapid progress in AI/ML has led to numerous applications in theoretical nuclear physics, often transforming how we carry out calculations and analyze data. I will review recent developments, including generative modeling of collider events, simulation-based inference at the event level, and novel search strategies for physics beyond the Standard Model. These techniques are relevant to current experiments at CEBAF, RHIC, and the LHC, as well as the future Electron-Ion Collider.

Speaker: Felix Ringer (Stony Brook University)

EINN25_FRinger.pdf

15:25 ML-Enhanced Neutron Detection in CLAS12 for Short-Ranged Correlation Studies

Short-ranged correlations (SRCs) provide insight into the fundamental forces that drive nuclear dynamics. Current experimental goals in this area include increasing precision in two-nucleon (2N) observables and the discovery and characterization of 3N SRCs. Exclusive measurements for these efforts require immense statistics and, given the tensor force’s preference for neutron-proton pairing, precise detection of both protons and neutrons.

CLAS12 is well-suited for such measurements due to its high luminosity and large angular coverage. In particular, the CLAS12 central detector offers complete azimuthal and broad polar-angle acceptance, as well as two dedicated scintillator arrays for neutral particle reconstruction. However, imperfect efficiency in tracking introduces a major source of background as untracked protons are generally reconstructed as neutrons.

To address this challenge, we design and implement a machine-learning algorithm that uses signals from the central detector to predict whether a CLAS-reconstructed neutron is correctly identified or instead an untracked charged particle. Our model is purely data-driven, with training and test samples taken from multiple exclusive reaction channels. As a baseline, we correctly reclassify 90% of misidentified protons, with performance stable across kinematic ranges and reaction channels.

I will present initial results using this model to extract the $e’pn/e’p$ cross-section ratio in $^{4}$He, providing both a validation of its performance and a significant improvement in the precision of this measurement of the short-range two-nucleon interaction.

Speaker: Natalie Wright (MIT)

15:50 The DNA of nuclear models: How does AI predict nuclear masses?

Obtaining high-precision predictions of nuclear masses, or equivalently nuclear binding energies, $E_b$, remains an important goal in nuclear-physics research. Recently, many AI-based tools have shown promising results on this task, some achieving a precision that surpasses the best human models. However, the utility of these AI models remains in question given that predictions are only useful where measurements do not exist, which inherently requires extrapolation away from the training (and testing) samples. Since AI models are largely \textit{black boxes}, the reliability of such an extrapolation is difficult to assess. We present an AI model that not only achieves cutting-edge precision for $E_b$, but does so in an interpretable manner. For example, we find that (and explain why) the most important dimensions of its internal representation form a double helix, where the analog of the hydrogen bonds in DNA here link the number of protons and neutrons found in the most stable nucleus of each isotopic chain. Furthermore, we show that the AI prediction of $E_b$ can be factorized and ordered hierarchically, with the most important terms corresponding to well-known symbolic models (such as the famous liquid drop). Remarkably, the improvement of the AI model over symbolic ones can almost entirely be attributed to an observation made by Jaffe in 1969. The end result is a data-driven model of nuclear masses that is fully interpretable.

Speaker: Sokratis Trifinopoulos (CERN)

Nuclear_DNA.pdf

16:15 The MAGIX Experiment at MESA

At the new high-intensity, low-energy electron accelerator MESA, the MAGIX experiment will enable high-precision scattering studies focused on the structure of hadrons and few-body systems, dark sector searches, as well as investigations of reactions relevant to nuclear astrophysics.

MAGIX features a fully windowless scattering chamber housing an internal gas jet target that can be operated with a variety of different gases, two high-precision magnetic spectrometers, and sophisticated detector systems positioned at the spectrometers’ focal planes. This setup, in combination with MESA’s high-intensity electron beam, ensures an exceptionally clean experimental environment, in which background effects like multiple scattering or energy straggling are drastically reduced.

The focal plane detectors include a tracking detector realized by a time projection chamber, as well as a trigger veto system composed of plastic scintillation detectors and passive lead absorbers. Additionally, a recoil detector system based on silicon strip detectors can be installed inside the scattering chamber to detect nuclear recoil particles in coincidence with the scattered electrons.

This contribution presents a detailed overview of the sophisticated experimental setup of MAGIX, including a glimpse at its rich and versatile physics program.

Speaker: Sebastian Stengel (Johannes Gutenberg University Mainz, Institute for Nuclear Physics)

SebastianStengel_TheMAGIXExperimentAtMESA.pdf

16:40 → 17:10 Coffee break

17:10 → 18:00 Parallel Workshop 1: Christian Bernard Hall

Christian Bernard Hall

17:10 Dalitz-plot decomposition of $e^+ e^- \to J/\psi \, \pi \, \pi$ process from 4.1271 to 4.3583 GeV employing dispersive analysis

We analyze the processes $e^+ e^- \to \gamma^* \to J/\psi \, \pi \, \pi \, (K \bar{K})$ and $e^+ e^- \to \gamma^* \to h_c \, \pi \, \pi$ using the recently proposed Dalitz-plot decomposition approach, based on the helicity formalism for three-body decays. Within a Lagrangian-based toy model, we validate key aspects of this approach, namely the factorization of the overall rotation for all decay chains and spin alignments, as well as crossing symmetry between final states. In analyzing the experimental data, we describe the subchannel dynamics through a dispersive treatment of $\pi\pi/K\bar{K}$ interactions, reproducing the $f_0(500)$ and $f_0(980)$ pole structures. Using recent $e^+ e^- \to J/\psi \, \pi \, \pi$ data in the 4.1271-4.3583 GeV range, we reproduce invariant mass spectra that reveal both $Z_c(3900)$ and $Z_c(4020)$ states and discuss prospects for further constraints on the $Y(4220)$ and $Y(4320)$.

Speaker: Viktoriia Ermolina (Johannes Gutenberg University of Mainz)

EINN2025Ermolina.pdf

17:35 Towards continuum limit of Meson Charge Radii using large volume configuration at physical point in Nf=2+1 lattice QCD

We present our preliminary determination of the charge radii of light mesons using the PACS10 configurations, which were generated at the physical point on large volumes of more than $(10\,\text{fm})^3$ by the PACS Collaboration. In general, charge radius calculations suffer from systematic effects due to chiral extrapolation, finite lattice spacing effect, finite volume effect, and the choice of fit ansatz. By employing the PACS10 configurations, we can control the first three systematics in a unified manner. Furthermore, we apply a model-independent extraction method to avoid the systematic uncertainty associated with the fit ansatz. Our preliminary results of the charge radii for $\pi^+$, $K^+$, and $K^0$ are consistent with experimental and previous lattice determinations, while exhibiting reduced uncertainties.

Speaker: Kohei Sato (Seikei University)

EINN2025_ksatoh.pdf

17:10 → 18:00 Parallel Workshop 2: Aphrodite Room

17:10 New physics searches in low-energy precision experiments

Various extensions of the Standard Model give rise to BSM particles with masses in the MeV to sub-GeV range. Such particles are often associated with dark matter, the strong CP problem and the $\left(g-2\right)_{\mu}$ anomaly. In this work, we examine the experimental constraints on such particles that can be derived from near-future high-precision experiments, including the MESA facility and the JLab program utilizing polarized positrons, alongside recent measurements of $\left(g-2\right)_l$. Special focus is placed on lepton couplings, which remain weakly constrained within this mass range.

Speaker: Aleksandr Pustyntsev (Johannes Gutenberg University of Mainz)

EINN2025PustyntsevUp.pdf

17:35 Status of the DarkMESA Experiment

At the Institute for Nuclear Physics in Mainz, the new electron accelerator MESA will be operational shortly. The high-power beam dump of the P2 experiment (150 MeV, 150 $\mu$A) is ideally suited for a parasitic dark sector experiment – DarkMESA.

The experiment is designed for the detection of Light Dark Matter (LDM), which in the simplest model couples to a massive vector particle, the dark photon $\gamma'$. It can potentially be produced in the beam dump by a process analogous to photon Bremsstrahlung and may then decay into Dark Matter (DM) particle pairs $\chi \bar{\chi}$. A fraction of them scatter off electrons or nuclei in the DarkMESA detectors.

This contribution discusses the extension of the simulation framework through the integration of additional models. The current status and first results of the Phase A setup will be shown. Beyond the use of a traditional calorimeter, the possibility of utilizing an opaque liquid scintillator for Phase B is under investigation. First simulation results, initial steps in prototype development, and exclusion limits obtained in co-operation with the NuDoubt$^{++}$ collaboration are presented.

Speaker: Mr Mirco Christmann (University of Mainz)

EINN2025_christmann.pdf

18:00 → 20:30 Poster session: Lobby of Christian Bernard Hall

Wednesday 29 October

09:00 → 10:30 Conference Talks: Christian Bernard Hall

Convener: Constantia Alexandrou (University of Cyprus & Cyprus Institute)

09:00 Overview of Charmonium-like Spectroscopy

In recent years, a number of charmonium-like XYZ states have been observed above the open-charm threshold in experiments like BABAR, BESIII, Belle(II) and LHCb. Their properties often go against our expectations for regular charmonium states, rendering their interpretation difficult. In this talk, I will give an overview of recent activities aiming to shed light on the nature of the XYZ states.

Speaker: Nils Hüsken (JGU Mainz)

einn_talk_2025_nh.pdf

09:30 Progress in three-particle scattering from lattice QCD

I will review recent advances in studying three-particle interactions directly from lattice QCD. By employing mathematical relations that connect discrete finite-volume energies and matrix elements to physical scattering and decay amplitudes, it is now possible to calculate observables that go beyond the single-hadron or elastic two-hadron regime. In addition to outlining the formalism, I will highlight recent applications and discuss future prospects and open challenges.

Speaker: Maxwell Hansen (University of Edinburgh)

10:00 Recent Results from GlueX

The detailed understanding of how quantum chromodynamics (QCD) gives rise to the spectrum of hadrons is currently one of the biggest open questions in hadron physics. Most of the observed states are classified as quark-antiquark mesons or three-quark baryons. However, QCD allows for a much richer spectrum with more complex configurations. Experimental evidence exists for such non-conventional hadrons like hybrid mesons, in which an excited gluonic field is coupled to a quark-antiquark pair and contributes directly to the meson properties.
Worldwide, different experimental facilities have dedicated and complementary hadron spectroscopy programs. The GlueX experiment, which is located in Hall D at Jefferson Lab, USA, uses a linearly polarized photon beam with energies of up to 12 GeV incident on a liquid hydrogen target and consists of a high-acceptance spectrometer with excellent charged as well as neutral particle detection capabilities. This allows us to study the production mechanisms and decays of a wide range of hadronic resonances.

This talk gives an overview of the recent results from the GlueX experiment.

Speaker: Farah Afzal (Ruhr University Bochum)

talk_EINN25_afzal.pdf

10:30 → 11:00 Coffee break

11:00 → 12:30 Conference Talks: Christian Bernard Hall

Convener: Richard Milner (MIT)

11:00 The [Future] Program of [PRad and] Dark Sector Searches at Jefferson Lab

The PRad-II and X17 Experiments are planned to run in Jefferson Lab’s Hall B in 2026. The common experimental setup includes a large-volume vacuum system, two planes of GEM tracking detectors for improved vertex and angle reconstruction, and a high-resolution calorimeter (HyCal). These experiments strive to give definite answers to long-standing questions in hadron physics. The X17 experiment is searching for a hypothetical light boson with a mass of about 17 MeV/c$^2$ that has been discussed to explain some anomalous nuclear transition data.
The HyCal could be re-used in the mid-term future as one of the calorimeter blocks for the Beam Dump eXperiment (BDX), an electron-beam thick-target experiment aimed to search for the existence of light Dark Matter particles in the MeV$-$GeV mass region at Jefferson Lab. BDX will be able to lower the exclusion limits by one to two orders of magnitude in the parameter space of dark-matter coupling versus mass.

Speaker: Patrick Achenbach (Jefferson Lab)

Achenbach-EINN-2025.pdf

11:30 Exploring strange hadronic matter through femtoscopy at the LHC

Understanding the interactions among strange hadrons is crucial for developing a realistic equation of state of nuclear matter in dense environments as in the interior of neutron stars. In recent years, significant theoretical progress has been achieved through Effective Field Theories, which provide interaction models anchored to experimental data, and through Lattice QCD calculations that enable first-principles studies of baryon-baryon and meson-baryon interactions. On the experimental side, major efforts at facilities such as DAΦNE, J-PARC, RHIC, FAIR, and the LHC have yielded increasingly precise measurements aimed at constraining and validating theoretical predictions. In this contribution, I will highlight the main achievements in this field, with a focus on the femtoscopy technique at the LHC. This method has provided the most precise information to date on the low-energy dynamics of several particle pairs in the strangeness sector, including systems with double and triple strangeness. Recent extensions to the three-body systems further demonstrate the capability of femtoscopy to investigate few-body dynamics for strange hadrons with unprecedented precision. Finally, I will discuss the implications of these measurements for our understanding of the equation of state of neutron stars.

Speaker: Raffaele Del Grande (Czech Technical University in Prague (CZ))

DelGrande_Cyprus_v4.pdf

12:00 Searching for Physics Beyond the Standard Model at the EIC

The Electron Ion Collider (EIC) is designed to further our understanding of hadronic physics. However, it could also provide opportunities to look for new phenomena beyond the Standard Model. In this talk, we will provide examples of such physics, with a focus on new light particles that may be associated with a dark sector. We will illustrate how the EIC can probe new model parameter space and complement searches in other experimental venues, over the coming decades.

Speaker: HOOMAN DAVOUDIASL (Brookhaven National Laboratory)

EINN2025-BSMatEIC-talk.pdf

12:30 → 15:00 Lunch Break

15:00 → 16:40 Parallel Workshop 1: Christian Bernard Hall

Christian Bernard Hall

15:00 Constraining the GPD E: Deeply Virtual Compton Scattering off the neutron with CLAS12 at Jefferson Lab

A key step toward a better understanding of the nucleon structure is the study of Generalized Parton Distributions (GPDs). GPDs are nowadays the object of an intense effort of research since they convey an image of the nucleon structure where the longitudinal momentum and the transverse spatial position of the partons inside the nucleon are correlated. Moreover, GPDs give access, via Ji's sum rule, to the contribution of the orbital angular momentum of the quarks to the nucleon spin. Deeply Virtual Compton scattering (DVCS), the electroproduction of a real photon off the nucleon at the quark level, is the golden process directly interpretable in terms of GPDs of the nucleon. The GPDs are accessed in DVCS mainly through the measurements of spin-dependent asymmetries. Combining measurements of asymmetries from DVCS experiments on both the neutron and the proton will allow performing the flavor separation of relevant quark GPDs via linear combinations of proton and neutron GPDs. This talk will give an overview of experiments aiming to constrain the GPD E, one of the least know GPDs. Focus will be directed towards the recently published neutron-DVCS measurements from the CLAS12 experiment at Jefferson Lab with the upgraded ~11 GeV CEBAF polarized electron beam. In particular, details on the measurement of Beam Spin Asymmetries from neutron-DVCS will be presented. The impact of the measurement on the extraction of the Compton form factor (CFF) E related to the GPD E of the neutron will be discussed. Further discussion will motivate the foreseen measurements with the CLAS12 experiment on a transversly polarized proton target aiming to extract the CFF E of the proton.

Speaker: Adam Hoballah Hobart (IJCLab CNRS-IN2P3)

EINN2025_Presentation_HOBALLAH.pdf

15:25 x-dependence of hadron GPDs at physical pion mass from the lattice

Generalized Parton Distributions (GPDs) provide a unified framework for exploring the three-dimensional structure of hadrons, encoding correlations between spatial and momentum distributions as well as spin and orbital angular momenta of quarks and gluons. Lattice QCD offers a first-principles approach to access these nonperturbative quantities, but long-standing challenges have limited calculations to low moments. Recent developments in large-momentum effective theory (LaMET) and related approaches have enabled direct studies of the full Bjorken-$x$ dependence of parton distributions, opening new opportunities for lattice inputs to global analyses.
In this talk, I will review the progress of lattice QCD calculations of parton distributions, with an emphasis on generalized parton distributions. I will highlight results on pion and nucleon GPDs at the physical pion mass and discuss recent advances in renormalization and matching, as well as systematic effects and strategies for controlling them. Together, these developments mark an exciting era where lattice QCD inputs can play a decisive role in unraveling the three-dimensional structure of hadrons.

Speaker: Huey-Wen Lin (Michigan State University)

2025-10-29_hwlin_EINN2025.pdf

15:50 Generalized Parton Distributions of the proton from Lattice QCD: Transversity case

With the upcoming Electron-Ion Collider, interest in proton tomography has greatly increased due to experiments, like DVCS are able to be conducted. A large set of functions that gives a great amount of information about the structure are Generalized Parton Distribution functions (GPDs). Recently, the $x$-dependence of GPDs has been extracted from lattice QCD. Utilizing a novel method that gives access to a wide range for the kinematic parameters (PRD 106 (2022) 11, 114512), we extract the transversity GPDs for the proton: $H_T$, $E_T$, $\tilde{H}_T$, and $\tilde{E}_T$. Calculations are done in zero-skewness with an $N_f = 2+1+1$ ensemble of twisted mass fermions with a clover improvement. The quark masses give a pion mass of roughly 260 MeV.

Speaker: Joshua Miller

16:15 TMD factorization at next-to-leading power

Theoretical control of soft interactions is fundamental to establish TMD factorization. It is possible to sistematically include soft interactions through soft modes in bacckground field method to reach a consistente factorization of SIDIS or Drell-Yan cross sections at next-to-leading power, where all nonperturbative terms are expressed as martix elements of field operators. As a practical example one can consider the case of jet production in SIDIS

Speaker: Ignazio Scimemi (Universidad Complutense Madrid)

15:00 → 16:40 Parallel Workshop 2: Aphrodite Room

15:00 AI-Enhanced BEGe Detectors for Low-Energy X-ray Collapse Model Tests

Testing the foundations of quantum mechanics requires experiments with
extremely high sensitivity to the detection of events, which, if they
occur, would have an extremely low rate. The VIP collaboration at the Gran
Sasso National Laboratory (LNGS) is performing tests on the spontaneous
collapse of the wave function, where recent results indicate that
different collapse models predict distinct photon emission features at low
energies (<10 keV). Here, I introduce tests carried out at LNGS by VIP
with a Broad-Energy Germanium Detector (BEGe) for probing spontaneous
emission in collapse theories. In this talk, I will present recent results
and describe the new methodologies and approaches being implemented to
reach progressively lower energy ranges. Special emphasis will be placed
on the development of a BEGe-based experimental setup, in which machine
learning techniques are employed to classify event waveforms and enhance
performance at low energies, where interference from microphonic noise
makes classification challenging with conventional pulse-shape analysis
techniques. These strategies represent a promising direction for extending
sensitivity to rare events and improving the ability to test foundational
models of quantum mechanics.

Speaker: Simone Manti (Istituto Nazionale di Fisica Nucleare)

EINN2025_29_10_2025_Manti_Simone.pdf

15:25 DVCS with polarized targets and CLAS12

Generalized Parton Distributions (GPDs) are nowadays the object of an intense effort of research, in the perspective of understanding nucleon structure. They describe the correlations between the longitudinal momentum and the transverse spatial position of the partons inside the nucleon and they can give access to the contribution of the orbital momentum of the quarks and gluons to the nucleon spin.
Deeply Virtual Compton scattering (DVCS), the electroproduction on the nucleon, at the partonic level, of a real photon, is the process more directly interpretable in terms of GPDs of the nucleon. Depending on the target nucleon (proton or neutron) and on the DVCS observable extracted (cross sections, target- or beam-spin asymmetries, …), different sensitivity to the various GPDs for each quark flavor can be exploited.
This talk will provide an overview on new, promising, DVCS-related experimental results, obtained at in Hall B at Jefferson Lab on longitudinally polarized hydrogenated and deuterated ammonia targets, with a 10.5-GeV electron beam, using the CLAS12 spectrometer. The future CLAS12 experiment to measure DVCS with a transversally polarized ammonia target will also be presented.

Speaker: Silvia Niccolai (IPN Orsay)

EINN2025_niccolai.pdf

15:50 The proton electromagnetic generalized polarizabilities

The electromagnetic polarizabilities of the proton are fundamental structure constants, that describe the proton’s response to an external electromagnetic (EM) field and quantify the deformation of the charge and magnetization distributions inside the proton caused by the electric or magnetic field, respectively. When studied through the virtual Compton scattering process, the virtuality of the photon provides access to the generalized polarizabilities, that open a powerful path to study the internal structure of the proton e.g. they map out the spatial distribution of the polarization densities in the proton, they provide access to key dynamical mechanisms that contribute to the electric and the magnetic polarizability effects, and allow to determine fundamental characteristics of the system, such as the electric and the magnetic polarizability radii. This talk will briefly review the recent progress on the topic, followed by a discussion of the VCS-II experiment that will have the first phase of data-taking in the spring of 2026 at Hall C/JLab, as well as of the future experimental program for the VCS measurements with a polarized electron beam at JLab (VCS-IIIp) that was recently approved by the JLab PAC.

Speaker: Nikos Sparveris

16:15 Compton amplitude and the nucleon structure functions from Lattice QCD

The structure of hadrons relevant for deep-inelastic scattering are completely characterised by the Compton amplitude. It is possible to directly calculate the Compton amplitude by taking advantage of the familiar Feynman-Hellmann approach applied in the context of lattice QCD. In principle, the x-dependent structure functions can be recovered from the amplitude or the amplitude itself can be incorporated to global QCD analyses. In this contribution, I will be highlighting QCDSF Collaboration's developments on computing the Compton amplitude and extracting the (moments of) structure functions.

Speaker: Utku Can (University of Adelaide)

can_einn25.pdf

16:40 → 17:10 Coffee break

17:10 → 18:00 Parallel Workshop 1: Christian Bernard Hall

Christian Bernard Hall

17:10 Unpolarized twist-two GPD and the trace anomaly

We present a one-loop perturbative study of unpolarized twist-two generalized parton distributions (GPDs) for external on-shell gluon states. A finite quark mass 𝑚 is kept throughout: it serves as an infrared regulator and, crucially, enables an explicit realization of the full trace-anomaly relation. By taking second Mellin moments, we extract the associated gravitational form factors (GFFs) in QED and QCD and verify the matching implied by the energy–momentum tensor operator identity, including the gluonic trace term. Particular attention is given to anomaly-induced “anomaly-pole” structures. The analysis complements our previous work on polarized twist-two GPDs and the axial anomaly, providing a unified picture of anomaly effects in partonic correlators.

Speaker: Ignacio Castelli

17:35 Continuum limit of the unpolarized gluon PDF using twisted-mass fermions

Gluons play a central role in the proton’s structure, carrying a substantial fraction of its momentum and driving its dynamics at small Bjorken-$x$. A precise determination of the unpolarized gluon parton distribution function (PDF) from first principles is essential for understanding QCD and for reducing uncertainties in high-energy collider predictions. In this talk, we extend our work on the unpolarized gluon PDF to a continuum limit extraction. We use four $N_f=2+1+1$ ensembles of maximally-twisted clover fermions and Iwasaki improved gluons at higher than physical pion mass with lattice spacings $a=0.094, \, 0.079, \, 0.069,$ and $0.057 \, \rm{fm}$. We provide an analysis of excited-state effects and compare our PDF to global fitting results.

Speaker: Joseph Delmar (Temple University)

Delmar_EINN_2025.pdf

17:10 → 18:00 Parallel Workshop 2: Aphrodite Room

17:10 Measurements of the nuclear dipole resonance with MAGIX at MESA

Nuclear multipole resonances have long been studied as a source of information on bulk nuclear properties. The nuclear dipole response has received much experimental and theoretical attention due to the proposed correlation between the pygmy dipole resonance (PDR) and the nuclear equation of state. Such a connection interprets the PDR in neutron-rich nuclei as the oscillation of the neutron skin against the symmetric nuclear core, correlating the strength of the PDR with the neutron skin thickness and nuclear symmetry energy. However, this connection remains model-dependent and controversial, and alternative interpretations of the PDR have been argued for. Additional experimental and theoretical efforts are required to clarify the situation.

Using electron scattering to excite nuclear resonances is complementary to experiments using real photons or hadronic probes. The MAGIX experiment, under construction at the MESA facility at JGU Mainz, is excellently suited for such measurements. MESA will deliver an electron beam with energies up to 105 MeV. Using a pair of magnetic spectrometers, MAGIX will reconstruct scattered electrons with high resolution ($\delta_p/p = 10^{-4}$) across a wide range of scattering angles. These capabilities will allow high-precision measurements of dipole resonances in a range of nuclei, further elucidating the connection of the dipole response to nuclear structure.

Speaker: Tyler Kutz (Johannes Gutenberg University Mainz)

17:35 Two-photon exchange effects in muonic hydrogen

Motivated by the expected improvement in the experimental determination of the $\mu$H Lamb shift measurement, I will present an updated fit of the unpolarised nucleon structure functions from available data in the nucleon resonance region in combination with Regge fits to the high-energy and deep inelastic region. The evaluation of the structure functions in the resonance region is building upon earlier work describing the resonance electrocouplings from exclusive data. The new fits of exclusive data will be a crucial part of a new parametrisation of the nucleon inelastic structure functions valid in a broad kinematic range. For the high-energy region, we start from the Regge-like parametrisation used for the structure functions $F_{1,2}$ in previous studies. The resonance and Regge regions are connected through analytic parametrisations constrained from inclusive electron scattering data from JLab. In this poster, I will present first results on the new parametrisation of nucleon unpolarised structure functions which will lead to updated data-driven evaluations of the two-photon exchange effects in the $\mu$H Lamb shift.

Speaker: Panagiotis Kalamidas

Thursday 30 October

09:00 → 10:30 Conference Talks: Christian Bernard Hall

Convener: Silvia Niccolai (IPN Orsay)

09:00 Progress of Polarizabilities from Lattice QCD

I will discuss a lattice QCD calculation of the nucleon electric polarizabilities at the physical pion mass. Our findings reveal the substantial contributions of the Nπ states to these polarizabilities. Without considering these contributions, the lattice results fall significantly below the experimental values, consistent with previous lattice studies. This observation has motivated us to compute both the parity-negative Nπ scattering up to a nucleon momentum of ∼ 0.5 GeV in the center-of-mass frame and corresponding Nγ∗ → Nπ matrix elements using lattice QCD. Our results confirm that incorporating dynamic Nπ contributions is crucial for a reliable determination of the polarizabilities from lattice QCD. This methodology lays the groundwork for future lattice QCD investigations into various other polarizabilities.

Speaker: Xu Feng (Columbia University)

09:30 Overview of Experimental Efforts on GPDs

An overview of the experimental activities for the study of generalised parton distributions will be presented. These include existing measurements of exclusive processes in lepton-hadron and hadron-hadron interactions as well as planned activities for the future.

Speaker: Charlotte Van Hulse

10:00 Phenomenology of GPDs and synergy with lattice QCD

Generalized parton distributions (GPDs) offer a powerful framework to access the multidimensional structure of hadrons, allowing in particular for so-called nucleon tomography and providing access to elements of the hadron energy–momentum tensor. The extraction of GPDs from experimental data is, however, challenging and often cannot be performed in a complete way due to difficulties arising from the deconvolution of amplitudes. In parallel, lattice QCD has achieved notable progress in computing quantities relevant to GPDs from first principles. The growing synergy between lattice results and phenomenological models provides new opportunities for cross-validation, improved parametrizations, and enhanced predictive power.

In my talk, I will highlight recent developments in GPD phenomenology, discuss ongoing efforts to integrate lattice inputs, and outline prospects for a unified description of hadron structure through combined theoretical and experimental approaches.

Speaker: Paweł Sznajder (National Centre for Nuclear Research, Poland)

10:30 → 11:00 Coffee break

11:00 → 12:30 Conference Talks: Christian Bernard Hall

Convener: Ignazio Scimemi (Universidad Complutense Madrid)

11:00 Hyperon Time-like Form Factors at BESIII

The never ending story of baryon time-like form factors continues and renew itself, fed by the powerful process of synergic and mutually reinforcing actions of experiments and theory.
Hyperons, with their self analyzing weak decays give the unique possibility to investigate the complex nature of form factors and mainly to test concepts based on first principles, which can be exploited to study dynamical mechanisms considered unknowable until recently.
BESIII analysis, with their accuracy, offer the opportunity of enhancing knowledge and understanding of the mechanisms underlying the electromagnetic interaction of hyperons.
I will review recent discoveries, highlighting new developments and improvements to existing knowledge—improvements that, in some cases, have actually rethought previously well-established concepts.

Speaker: Prof. Simone Pacetti (Istituto Nazionale di Fisica Nucleare)

11:30 Overview of Recent Developments for TMDs

In this talk I will review the current status of transverse momentum dependent (TMD) physics and related phenomena, including both unpolarized and polarized observables. Such studies give us insight into the 3-dimensional structure of hadrons. The focus of the talk will be on recent developments in theory and phenomenology regarding the extraction of TMD parton distribution functions and fragmentation functions (TMDs). The talk will also cover connections of TMDs to aspects of high-energy physics, lattice QCD, and AI/ML.

Speaker: Daniel Pitonyak (Lebanon Valley College)

Pitonyak_EINN2025.pdf

12:00 Overview of Recent Developments of TMDs from Lattice QCD

In recent years, significant progress has been made in extracting transverse-momentum-dependent (TMD) hadron structure from lattice QCD. In this talk, I will give a brief overview of recent developments in lattice calculations of TMD physics, including the determination of the soft function, the Collins–Soper kernel, and the computation of TMD parton distribution functions and TMD wave functions.

Speaker: Jianhui Zhang (The Chinese University of Hong Kong, Shenzhen)

12:30 → 15:00 Lunch Break

15:00 → 16:40 Joint session Workshop 1 and 2: Christian Bernard Hall

15:00 Baryon resonances from lattice QCD

Lattice QCD calculations have now reached the maturity required to determine the properties of hadronic resonances from first principles. In this talk, I will review recent progress on baryon resonances, with particular emphasis on the $\Lambda(1405)$, the $\Delta(1232)$, and two-nucleon systems. I will also outline the path toward exploring higher-lying resonances in QCD, highlighting recent advances that open the way to the study of three-hadron resonances.

Speaker: Fernando Romero-Lopez (Uni Bern)

15:25 Progress for x-dependent GPDs from Lattice QCD

In this talk, we discuss the recent progress in lattice QCD determinations of generalized parton distributions. The recently developed framework of asymmetric frames of reference, now complete for the vector, axial vector and tensor cases, allows for cost effective calculations of GPDs across a broad range of kinematics. This makes the prospects of their full mapping realistic in the near future, although requiring careful quantification of all systematic effects. We show a selection of our recent results and discuss future prospects, involving also synergy with phenomenology and experiment.

Speaker: Krzysztof Cichy (Adam Mickiewicz University, Faculty of Physics)

15:50 Nucleon electromagnetic form factors at large momentum from Lattice QCD

Proton and neutron electric and magnetic form factors are the primary characteristics of their spatial structure and have been studied extensively over the past half-century. At large values of the momentum transfer $Q^2$ they should reveal transition from nonperturbative to perturbative QCD dynamics and effects of quark orbital angular momenta and diquark correlations. Currently, these form factors are being measured at JLab at momentum transfer up to $Q^2=18$ GeV$^2$ for the proton and up to 14 GeV$^2$ for the neutron. We will report an updated calculation of these form factors using nonperturbative QCD on the lattice, including $G_E$ and $G_M$ nucleon form factors with momenta up to $Q^2=12$ GeV$^2$, pion masses down to the almost-physical $m_\pi$=170 MeV, several lattice spacings down to $a=0.073$ fm, and high $O(10^5)$ statistics. Specifically, we study the $G_E/G_M$ ratios, asymptotic behavior of the $F_2/F_1$ ratios, and flavor dependence of contributions to the form factors. We observe some qualitative agreement of our ab initio theory calculations with experiment. Comparison of our calculations and upcoming JLab experimental results will be an important test of nonperturbative QCD methods in the almost-perturbative regime.

Speaker: Dr Sergey Syritsyn (Stony Brook University)

16:15 Kaon semileptonic form factors at the physical quark masses on large volumes in lattice QCD

We present our results for the kaon semileptonic form factors calculated
by using the $N_f=2+1$ and $2+1+1$ PACS10 configuration, whose physical volumes
are more than $($10 fm$)^4$ at the physical quark masses in the lattice spacings
from 0.04 to 0.08 fm. The configurations were generated using the Iwasaki
gauge action and stout-smeared clover quark action. The form factors near
zero momentum transfer can be calculated thanks to the large volume.
Using our data, a stable interpolation of the form factors to zero momentum
transfer is carried out. The value of $|V_{us}|$ is determined using
the interpolated result of the form factors at zero momentum transfer.
Our value of $|V_{us}|$ is compared with a prediction of the standard model
estimated from the CKM matrix unitarity and with those determined using
the previous lattice results.

Speaker: Takeshi Yamazaki (University of Tsukuba)

16:40 → 17:00 Coffee break

17:00 → 18:30 Conference Talks: Oral presentation of three best posters - Christian Bernard Hall

Convener: Martha Constantinou (Temple University)

Friday 31 October

09:00 → 10:30 Conference Talks: Christian Bernard Hall

Convener: Evgeny Epelbaum

09:00 New Results on 2N and 3N Short-Range Correlations

The existence of two-nucleon short-range correlations (2N SRCs) has been well established by a series of experiments at SLAC and Jefferson Lab. The inclusive measurements showed a universal behavior in A/D cross section ratios of quasielastic scattering at x>1 and moderate Q2 yielding a constant value. In these kinematics mean field contributions fall off rapidly and 2N SRC contributions dominate. In even higher x-values (x>2), it was argued that contributions from 3N SRCs might dominate. Existing experimental searches for 3N SRCs have yet to provide unambigious and significant evidence for them. A recent 12 GeV Jefferson Lab experiment measured the quasi-elastic scattering off various nuclei in the kinematic region that is sensitive to the 3N SRCs. This talk will discuss the state of the field and present new results on 2N and 3N SRCs.

Speaker: Nadia Fomin

09:30 Effective Field Theories for Few-Nucleon Systems

The low-energy limit of QCD is represented by a tower of effective field theories (EFTs): Chiral, Pionless, Halo/Cluster, and Roto-Vibrational, with perhaps others still to be developed. EFTs have transformed the landscape of nuclear theory by providing a systematic framework to account for multi-body forces and currents following the same tenets used in other areas of physics. However, issues of consistency remain with the most popular, Chiral EFT. I will describe recent developments in the simpler, Pionless EFT to illustrate how it provides a basis for nuclear structure and reactions that is consistent with QCD.

Speaker: Ubirajara Van Kolck

10:00 Lattice QCD calculations for Nuclear Physics

Lattice QCD has matured into a powerful nonperturbative tool for directly probing the low-energy regime of the strong interaction from the QCD Lagrangian. Specifically, lattice QCD now offers quantitative insights into two- and three-nucleon interactions, nuclear binding energies, hypernuclear forces, and electroweak matrix elements relevant to neutrino-nucleus scattering and double beta decay. Despite the challenges of signal-to-noise degradation and computational scaling for multi-baryon systems, recent algorithmic developments and analysis techniques have enabled ab initio calculations of hadronic and nuclear observables with increasing precision. Moreover, lattice QCD plays a pivotal role in constraining effective field theories and informing phenomenological models, bridging the gap between fundamental theory and experimental observables.

In this talk, I will present key results obtained by the NPLQCD collaboration. I will focus on baryon-baryon interactions and discuss how these findings compare with results from other lattice collaborations.

Speaker: Assumpta Parreño (University of Barcelona)

10:30 → 11:00 Coffee break

11:00 → 12:30 Conference Talks: Christian Bernard Hall

Convener: Igor Danilkin (Johannes Gutenberg University of Mainz)

11:00 AMBER - First results and future plans

AMBER is a new QCD facility at CERN's SPS M2 secondary beam line, which aims to study fundamental properties of hadrons. The first approved experimental phase includes measuring the antiproton production cross-section, which is essential for indirect dark matter searches using cosmic-ray antiprotons. It also includes measuring the proton's charge radius using high-energy muons and investigating hadron structure and the emergence of hadron mass using Drell–Yan reactions and charmonium production.
In this talk, I will outline the physics motivations and methodologies behind the various AMBER measurements and their anticipated scientific impact. I will present the first results from the antiproton-production measurements conducted in 2023 and 2024, as well as the current status of preparations for future measurements, particularly the proton radius measurement. I will also briefly discuss plans for a second phase of AMBER, which will focus on measurements with a high-intensity kaon beam after 2030.

Speaker: Bernhard Ketzer (University of Bonn)

11:30 MESA and the low-energy precision frontier

The intensity frontier offers a complementary approach to high-energy colliders, as high-precision measurements can provide unprecedented constraints on new physics, fundamental interactions, and the structure of matter. The Mainz Energy-recovering Superconducting Accelerator (MESA) is a cutting-edge facility that will push the limits of high-intensity, low-energy hadronic physics. MESA’s flagship experiments, MAGIX and P2, will carry out high-precision measurements of the weak mixing angle, nucleon form factors, and nuclear weak radii and cross sections. These will enable stringent tests of the Standard Model, searches for dark matter, and further our understanding of the electromagnetic structure of nucleons and nuclei.

Speaker: Tyler Kutz (Johannes Gutenberg University Mainz)

12:00 Heavy-Ion Collisions as a Precision Laboratory for Hot and Cold QCD

I review recent developments in the field of heavy ion collisions and quark gluon plasma physics with focus on the role of nucleon and nuclear structure, electromagnetic probes, as well as connections to the future Electron Ion Collider.

Speaker: Bjoern Schenke (Brookhaven National Laboratory)

12:30 → 14:00 Lunch Break

14:00 → 19:30 Excursion

19:30 → 22:00 Social dinner: Kouklia Village

Saturday 1 November

10:00 → 10:40 Conference Talks: Christian Bernard Hall

Convener: Achim Denig (JGU Mainz)

10:00 Directions in hadronic physics: experiment

The status and plans for experimental programs in hadronic physics in Asia, Europe and N. America will be summarized.

Speaker: Richard Milner (MIT)

10:40 → 11:30 Coffee break

11:30 → 12:20 Conference Talks: Christian Bernard Hall

Convener: Barbara Pasquini (Istituto Nazionale di Fisica Nucleare)

11:30 Directions in hadron physics: theory

Plan for Nuclear Science and the NuPECC 2024 Long Range Plan for European Nuclear Physics. Both reports emphasize the central role of QCD-focused nuclear theory in supporting and guiding the hadron physics program. This talk will outline the major directions for hadron physics theory in the coming decade, highlight the big science questions that must be addressed, discuss the evolving research and funding landscape, and describe the new tools and approaches that theory should embrace.

Speaker: Ian Cloet

12:10 Closing

Speaker: Martha Constantinou (Temple University)

12:20 → 14:20 Farewell Lunch

Included in registration