From pialjp at jlab.org Wed Oct 1 10:04:36 2025 From: pialjp at jlab.org (Pia Jones Petrak) Date: Wed, 1 Oct 2025 10:04:36 -0400 Subject: [Theory-seminars] Cake Seminar TODAY Message-ID: <1b603c45-5467-4e18-84c3-b889ac2fd31e@jlab.org> Hey everyone, At 1pm TODAY*please join us in L102* for a Cake Seminar by*Zhite Yu*. Zoom: https://jlab-org.zoomgov.com/j/1611917868?pwd=xEbiVczPWIxYEntBlc0ofCEDOF3rkm.1 *Title:* Accessing x-dependent GPDs from generative AI * * *Abstract:* Obtaining the x-dependent generalized parton distributions (GPDs) is essential for advancing our understanding of hadron tomography. However, this goal has been hindered by the limited sensitivity of most well-known experimental processes, such as deeply virtual Compton scattering (DVCS) and time-like Compton scattering (TCS). In this talk, I will compare these traditional processes with new ones that offer enhanced sensitivity to the x-dependence. By employing a pixelated GPD construction using a normalizing flow neural network, we can visualize and quantitatively examine the point-by-point sensitivity encoded in the physical processes. Best wishes, Adam, Joe, and Pia -------------- next part -------------- An HTML attachment was scrubbed... URL: From pialjp at jlab.org Mon Oct 6 10:09:17 2025 From: pialjp at jlab.org (Pia Jones Petrak) Date: Mon, 6 Oct 2025 10:09:17 -0400 Subject: [Theory-seminars] Theory Seminar TODAY Message-ID: <5c9470fa-0e4e-411d-9df1-205652058e74@jlab.org> Hey everyone, We will be having a remote Theory seminar *today at 1pm*. Even though it's remote *please join us in L102 or on Zoom*. Below is the info* * * * Speaker: Jacob Barandes (Harvard University) Zoom:**https://jlab-org.zoomgov.com/j/1607122942?pwd=jwL6454csz4ssfGwtKJY8HawT0XqYU.1 * * Titel: Probability, Indivisibility, and Quantum Theory Abstract: In textbooks, quantum theory is usually defined in terms of a complicated collection of abstract mathematical ingredients, like wave functions, Hilbert spaces, and self-adjoint operators. One then plugs these ingredients into special formulas that produce probabilities that we can verify with laboratory measurements. But the axioms of the textbook theory do not explain why these special formulas are true, or how probabilities emerge from them. The axioms also exhibit various ambiguities and gaps, the most famous of which is known as ?the measurement problem.? Quantum foundations is an area of research devoted to studying and resolving these sorts of problems. Over the past century, these efforts have produced a remarkable number of important spin-offs, including entanglement, decoherence, quantum advantage, and the Bell inequality (which led to the 2022 Nobel Prize in Physics). It would be an understatement to say that a large fraction of current research in physics relies on these spin-offs. In this talk, I will describe a novel approach to quantum foundations based on a newly discovered correspondence between quantum systems and ?indivisible? stochastic processes. After explaining what indivisible stochastic processes are, starting from their first appearance in the research literature in 2021, I will show how to use this correspondence to reconstruct quantum theory in terms of ordinary notions of probability playing out through a classical picture of the world. The resulting indivisible formulation of quantum theory does not include wave functions or Hilbert spaces among its physical objects. Nor does it involve parallel universes, pilot waves, alive-and-dead cats, or other famously exotic ingredients. The indivisible theory makes the world safe for ordinary probability theory, potentially opens the door to new generalizations of quantum theory, and suggests that quantum theory and quantum computers might provide more efficient techniques for simulating stochastic processes beyond the Markov approximation, with potential applications for statistical modeling, finance, neuroscience, and ecology, among other areas. Bio: Jacob Barandes did his PhD in quantum gravity at Harvard, where he is now on the faculty with appointments in both the physics and philosophy departments, and is also a faculty affiliate with Harvard's Black Hole Initiative. Jacob's work consists of ?philosophical physics,? in which one uses the tools of analytic philosophy to make progress on open problems in physics, as well as ?physical philosophy,? which means trying to determine what our best physical theories can tell us about questions in metaphysics and the philosophy of science. He is particularly interested in quantum foundations and the metaphysics of causation. In addition to his research and teaching at Harvard, Jacob organizes Harvard's annual New England Workshop on the History and Philosophy of Physics, as well as a regular seminar series on the foundations and philosophy of physics. Best wishes, Adam, Joe, Pia -- Pia Leonie Jones Petrak Postdoctoral Fellow Theoretical and Computational Physics Center Jefferson Lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From afreese at jlab.org Tue Oct 7 13:07:10 2025 From: afreese at jlab.org (Adam Freese) Date: Tue, 7 Oct 2025 17:07:10 +0000 Subject: [Theory-seminars] Papers by Jacob Barandes Message-ID: Greetings everyone, Following yesterday's seminars, I will provide links to papers by the speaker, Jacob Barandes, relevant to the seminar he gave, in case anyone is interested in reading more into his work. The paper Jacob mentioned during the seminar, which discusses the stochastic-quantum correspondence and was just recently published, is here: https://inspirehep.net/literature/2635190 In addition, there are three more recent preprints building on the formalism: https://inspirehep.net/literature/2693952 https://inspirehep.net/literature/2762243 https://inspirehep.net/literature/2955249 The second of these preprints discusses the interaction of Jacob's formalism with Bell's theorem, and in my opinion gives an excellent introduction to Bell's theorem as well. I hope these links may prove useful and instructive. Kind regards, Adam -------------- next part -------------- An HTML attachment was scrubbed... URL: From jkarpie at jlab.org Tue Oct 7 13:38:33 2025 From: jkarpie at jlab.org (Joseph Karpie) Date: Tue, 7 Oct 2025 17:38:33 +0000 Subject: [Theory-seminars] Cake Seminar tomorrow Message-ID: Hey everyone, On Wednesday at 1pm, please join us in L102 where Alex Sturzu (WM) will be giving a cake seminar. Zoom: https://jlab-org.zoomgov.com/j/1618125035?pwd=J8ft2fuWpqUyYeaerlI4XtKFdpTrwP.1 Title: Flowed gluon momentum fractions: A gradient flow-based renormalization approach The parton momentum fractions carry important information about the nucleon mass and spin decompositions. Specifically, determining the gluon contribution to nucleon momentum is a key step in achieving a better understanding of the nucleon structure. In this talk I present recent work by the HadStruc collaboration on determining the gluon momentum fraction from lattice quantum chromodynamics using a novel renormalization procedure based on the gradient flow, a nonperturbative damping of ultraviolet fluctuations. The ratio of three- to two-point correlation functions, constructed from nucleon and gluon operators, are used to build linear combinations of different matrix elements that ultimately provide access to the momentum fraction. The use of distillation and the variational method to improve the signal of the nucleon states will also be discussed. The nonperturbative renormalization and MS-bar scheme matching is done via a set of coefficients built from the short flow-time expansion. The application of these coefficients are detailed. Best, Adam, Joe, and Pia -- Joe Karpie Pronouns: He/His/Him Postdoctoral Fellow Theoretical and Computational Physics Center Jefferson Lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From jkarpie at jlab.org Sun Oct 12 14:57:19 2025 From: jkarpie at jlab.org (Joseph Karpie) Date: Sun, 12 Oct 2025 18:57:19 +0000 Subject: [Theory-seminars] Theory Seminar Monday Message-ID: Hello everyone, We will be having a seminar Monday by Ivan Mauricio Burbano Aldana (UC Berkeley) at 1pm in F326-327 Title: Real-time Estimators of Scattering Observables Abstract: The real-time correlators of quantum field theories can be directly probed through new approaches to simulation, such as quantum computing and tensor networks. This provides a new framework for computing scattering observables in lattice formulations of strongly interacting theories, such as lattice quantum chromodynamics. In this talk, we will go over the proof given in arXiv: 2506.06511, showing that the proposal of Real-time Estimators of Scattering Observables is universally applicable to all scattering observables of gapped quantum field theories. All finite-volume errors are exponentially suppressed, and the rate of this suppression is controlled by the regulator considered, namely, a displacement of the spectrum of the theory into the complex plane. A partial restoration of Lorentz symmetry by averaging over different boosts gives an additional suppression of finite volume errors. Our results also apply to the simulation of wavepacket scattering, where a similar averaging is performed to construct the wavepackets that regulate the finite volume effects. We also comment on potential applications of our results to traditional computational schemes. Best, Joe -- Joe Karpie Pronouns: He/His/Him Postdoctoral Fellow Theoretical and Computational Physics Center Jefferson Lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From pialjp at jlab.org Mon Oct 13 09:42:34 2025 From: pialjp at jlab.org (Pia Jones Petrak) Date: Mon, 13 Oct 2025 09:42:34 -0400 Subject: [Theory-seminars] Theory Seminar TODAY In-Reply-To: References: Message-ID: <76ddfc80-608c-47e0-853d-31a22d3f18c4@jlab.org> Hello everyone, We will be having a remote Theory seminar *today at 1pm*. Even though it's remote *please join us in?F326-327 *or on Zoom. Below is the info. Speaker: Iv?n Mauricio Burbano Aldana (UC Berkeley) Zoom: https://jlab-org.zoomgov.com/j/1617081564?pwd=0Tr7fZACG5vyHvFjgaye73eQpUJ43l.1 Title: Real-time Estimators of Scattering Observables Abstract:?The real-time correlators of quantum field theories can be directly probed through new approaches to simulation, such as quantum computing and tensor networks. This provides a new framework for computing scattering observables in lattice formulations of strongly interacting theories, such as lattice quantum chromodynamics. In this talk, we will go over the proof given in arXiv: 2506.06511, showing that the proposal of Real-time Estimators of Scattering Observables is universally applicable to all scattering observables of gapped quantum field theories. All finite-volume errors are exponentially suppressed, and the rate of this suppression is controlled by the regulator considered, namely, a displacement of the spectrum of the theory into the complex plane. A partial restoration of Lorentz symmetry by averaging over different boosts gives an additional suppression of finite volume errors. Our results also apply to the simulation of wavepacket scattering, where a similar averaging is performed to construct the wavepackets that regulate the finite volume effects. We also comment on potential applications of our results to traditional computational schemes. Best wishes, Adam, Joe, and Pia -------------- next part -------------- An HTML attachment was scrubbed... URL: From jkarpie at jlab.org Tue Oct 14 09:45:53 2025 From: jkarpie at jlab.org (Joseph Karpie) Date: Tue, 14 Oct 2025 13:45:53 +0000 Subject: [Theory-seminars] Cake Seminar Wednesday Message-ID: Hey yall, Please join us in L102 Wednesday at 1pm for a Cake Seminar by Kiminad Mamo. Zoom: https://jlab-org.zoomgov.com/j/1615168742?pwd=UL5q5N2WwMQS7NymAK4k0ffwbA8tue.1 Title: From Light-Meson and Heavy-Quarkonia Production to Proton Structure: Holographic Amplitudes, Gluonic GFFs, and All-Skewness GPDs Abstract: I will present a unified, string-based holographic framework for exclusive electro- and photoproduction at Jefferson Lab and future EIC, applied consistently to light mesons and heavy quarkonia. The scattering amplitude is built from Witten diagrams with Reggeized t?channel exchange and admits a conformal partial?wave (Gegenbauer/Mellin) representation?an infinite sum over conformal moments of the underlying GPDs. This construction makes the t?channel dynamics (Reggeon/Pomeron) explicit while enforcing support, crossing, and polynomiality by design. For J/psi (and Upsilon) electro/photoproduction the same amplitude connects near?threshold and high?energy regimes and enables an experimental determination of the proton?s gluonic gravitational form factors A(t) and D(t). Using this holographic amplitude, the J/psi?007 Collaboration at JLab extracted A(t) and D(t) from exclusive data, tying cross sections to the proton?s mass radius, pressure, and shear; the resulting gluonic GFFs are in very good agreement with lattice?QCD determinations over the probed spacelike range. Electromagnetic form?factor results in the same soft?wall framework are used to calibrate the relevant Regge scales and normalizations. I will also outline our forthcoming neutral?pion analysis above the resonance region. The anomaly?fixed Chern?Simons VAV coupling controls the forward t?channel residue F_t(Q^2, s, t), while nucleon s/u Born terms account for central/backward angles. A single holographic form factor governs the observed Q^2 and t dependences and yields transverse dominance at forward angles?providing a clean bridge to the deep?exclusive regime and a direct link to transversity?GPD conformal moments. Motivated by the amplitude?GPD duality above, I will introduce a conformal?moment parametrization of quark and gluon GPDs valid at any skewness. With minimal Regge input anchored by electromagnetic and gravitational form factors, the resulting GPDs agree with lattice benchmarks in both moment space and reconstructed x?space and deliver testable predictions for JLab and future EIC. -- Joe Karpie Pronouns: He/His/Him Postdoctoral Fellow Theoretical and Computational Physics Center Jefferson Lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From jkarpie at jlab.org Wed Oct 15 11:02:51 2025 From: jkarpie at jlab.org (Joseph Karpie) Date: Wed, 15 Oct 2025 15:02:51 +0000 Subject: [Theory-seminars] Cake Seminar Message-ID: Hey yall, Please join us in L102 today at 1pm for a Cake Seminar by Kiminad Mamo. Zoom: https://jlab-org.zoomgov.com/j/1615168742?pwd=UL5q5N2WwMQS7NymAK4k0ffwbA8tue.1 Title: From Light-Meson and Heavy-Quarkonia Production to Proton Structure: Holographic Amplitudes, Gluonic GFFs, and All-Skewness GPDs Abstract: I will present a unified, string-based holographic framework for exclusive electro- and photoproduction at Jefferson Lab and future EIC, applied consistently to light mesons and heavy quarkonia. The scattering amplitude is built from Witten diagrams with Reggeized t?channel exchange and admits a conformal partial?wave (Gegenbauer/Mellin) representation?an infinite sum over conformal moments of the underlying GPDs. This construction makes the t?channel dynamics (Reggeon/Pomeron) explicit while enforcing support, crossing, and polynomiality by design. For J/psi (and Upsilon) electro/photoproduction the same amplitude connects near?threshold and high?energy regimes and enables an experimental determination of the proton?s gluonic gravitational form factors A(t) and D(t). Using this holographic amplitude, the J/psi?007 Collaboration at JLab extracted A(t) and D(t) from exclusive data, tying cross sections to the proton?s mass radius, pressure, and shear; the resulting gluonic GFFs are in very good agreement with lattice?QCD determinations over the probed spacelike range. Electromagnetic form?factor results in the same soft?wall framework are used to calibrate the relevant Regge scales and normalizations. I will also outline our forthcoming neutral?pion analysis above the resonance region. The anomaly?fixed Chern?Simons VAV coupling controls the forward t?channel residue F_t(Q^2, s, t), while nucleon s/u Born terms account for central/backward angles. A single holographic form factor governs the observed Q^2 and t dependences and yields transverse dominance at forward angles?providing a clean bridge to the deep?exclusive regime and a direct link to transversity?GPD conformal moments. Motivated by the amplitude?GPD duality above, I will introduce a conformal?moment parametrization of quark and gluon GPDs valid at any skewness. With minimal Regge input anchored by electromagnetic and gravitational form factors, the resulting GPDs agree with lattice benchmarks in both moment space and reconstructed x?space and deliver testable predictions for JLab and future EIC. -- Joe Karpie Pronouns: He/His/Him Postdoctoral Fellow Theoretical and Computational Physics Center Jefferson Lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From pialjp at jlab.org Mon Oct 20 10:23:47 2025 From: pialjp at jlab.org (Pia Jones Petrak) Date: Mon, 20 Oct 2025 10:23:47 -0400 Subject: [Theory-seminars] Theory Seminar TODAY Message-ID: Hey everyone, We will be having a remote Theory seminar *today at 1pm*. Even though it's remote *please join us in L102 or on Zoom*. Below is the info* * Speaker: Raoul Hodgson (DESY Zeuthen) Zoom: https://jlab-org.zoomgov.com/j/1604596152?pwd=mibAQ8ziTyr1yrngbs2IIobuEyvuWn.1 Title: Rare Kaon and Hyperon Decays from Lattice QCD Abstract: The rare kaon and hyperon decays K -> pi l^+ l^- and Sigma^+ -> p l^+ l^- are flavour-changing-neutral-currents that are highly suppressed within the Standard Model making them excellent probes of new physics Beyond the Standard Model. However, existing theoretical predictions of these processes are complicated by the non-perturbative nature of low-energy QCD. I will present the progress made towards first principles calculations of these decays using Lattice QCD. Best wishes, Adam, Joe, and Pia -------------- next part -------------- An HTML attachment was scrubbed... URL: From jkarpie at jlab.org Sat Oct 25 21:03:34 2025 From: jkarpie at jlab.org (Joseph Karpie) Date: Sun, 26 Oct 2025 01:03:34 +0000 Subject: [Theory-seminars] Theory Seminar Monday Message-ID: Hey everyone, Please join us in on Monday at 1pm in L102 for a Theory seminar from Xilin Zhang (FRIB/MSU). Zoom: https://jlab-org.zoomgov.com/j/1604987727?pwd=5lmvFZ8c2byJITY4aMlPSsoy2zwNZ9.1 Title: Recent Advances in Nuclear Continuum Theory and Computation Abstract: the nuclear continuum theory is foundational to low-energy nuclear physics, elucidating reaction dynamics probed at facilities like the Facility for Rare Isotope Beams and supporting fields such as nuclear astrophysics. This subject also shares a close theoretical foundation with hadronic continuum physics, a connection I will explore in this talk. My primary focus is to introduce several developments from my own work in low-energy nuclear continuum physics. I will present two ab initio methods (2004.13575, 2408.03309) developed to extend continuum calculations across the nuclear chart, where such efforts are currently confined to light systems. These developments have yielded fresh insights into general continuum physics and offered new perspectives on computational strategies that may prove relevant to the hadronic physics community. A second topic is the development of emulators (or surrogate models) for continuum calculations (2007.03635, 2110.04269), a powerful tool for dramatically reducing computational costs in tasks like model calibration and uncertainty quantification. I will speculate on their potential application in hadronic physics and invite the audience to explore these parallels. Finally, I will briefly touch on how these advances could integrate with emerging deep-learning techniques to push the frontiers of quantum many-body continuum calculations (2504.20195). -- Joe Karpie Pronouns: He/His/Him Postdoctoral Fellow Theoretical and Computational Physics Center Jefferson Lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From jkarpie at jlab.org Mon Oct 27 16:32:01 2025 From: jkarpie at jlab.org (Joseph Karpie) Date: Mon, 27 Oct 2025 20:32:01 +0000 Subject: [Theory-seminars] Cake Seminar Wed Message-ID: Hey everyone, On Wednesday we will be welcoming Ming Li, a new professor at Hampton U, who will give our Cake Seminar at 1pm. Please join us in the Auditorium or just outside in the lobby for refreshments beforehand Title: Toward Understanding Proton?s Spin Structure at Small x Abstract: Understanding how individual quarks and gluons contribute to the proton?s total spin 1/2 is one of the main topics in the study of the proton?s internal structure. At present, state-of-the-art global fittings still fall short of fully explaining proton?s total spin, with one of the least understood contributions coming from quarks and gluons at small longitudinal momentum fraction x. In this talk, I will discuss recent theoretical advances toward understanding the proton?s spin structure at small x, particularly on the development of small-x helicity evolution equations and on incorporating data from longitudinally polarized proton-proton collisions to constrain the initial conditions. -- Joe Karpie Pronouns: He/His/Him Postdoctoral Fellow Theoretical and Computational Physics Center Jefferson Lab -------------- next part -------------- An HTML attachment was scrubbed... URL: