CTEQ Fall meeting 2024

21 Nov 2024, 08:30 → 22 Nov 2024, 18:30 America/New_York

Trible Library Theater (Christopher Newport University)

Alberto Accardi (CNU and Jefferson Lab), Paul Reimer

2024 Fall CTEQ meeting @ CNU, Nov 21-22. 

The Fall 2024 CTEQ meeting will be hosted by Christopher Newport University in the Trible Library's theatre by the Department of Physics, Computer Science and Engineering.

The meeting consists of a one and a half days physics session open to everyone, and a half day internal CTEQ business meeting. For the open meeting, we invite CTEQ collaborators and friends to discuss:

• Current work on, and future of, QCD spanning JLab, the EIC, and the LHC (and related facilities);
• Impact of PDFs on measurements and reliable prediction of uncertainties
• Synergies with lattice QCD
• Other ideas and collaborative projects

Emphasis will be given to questions and discussion.

Registration will be $120 to include light breakfast and coffee breaks on Thursday and Friday,  and a reception/dinner on Thursday evening. Please pay the registration fee at this link (you will need to create an account in the IRIS system, but it takes 2 minutes).

Please register already through the link in the left menu bar so that we can have an idea of the expected attendance. Please, also submit an abstract if you would like to give a talk. Students and postdocs are especially encouraged to present their work and ideas. If interest is high, we may organize a series of topical flah talks followed by discussion time in addition to regular talks.

Here is our group photo (and a higher resoultion image is available under "Materials" at the bottom of the page):

Organized by:

Alberto Accardi (CNU, co-Chair) Matteo Cerutti (CNU) Ralph Marinaro (CNU) Peter Monaghan (CNU) Paul Reimer (Argonne, co-Chair) Reinhard Schwienhorst (MSU) Huey-Wen Lin (MSU)

School of Engineering and Computing at Christopher Newport University .

 

 

 

2024-1122-CTEQ-Group-01952.jpg

Thursday 21 November

08:30 → 09:00 Light breakfast

09:00 → 10:30 Public Session

Extra non-structured time for discussions and follow-up chats.

09:00 Welcome by Dr. Quentin Kidd, CNU Provost and Executive Vice President

09:15 Workshop overview

Speaker: Alberto Accardi (Christopher Newport U. and Jefferson Lab)

Welcome - Accardi.pdf

09:30 Automated studies of PDF parametrizations

We present a methodology to automate the generation of polynomial shapes for parton distribution functions (PDFs). Our recent studies demonstrate that the freedom in parametrization choice contributes a large part of PDF uncertainties. Using Bézier curves, we construct error bands for pion PDFs as a demonstration of a general approach that can be applied in other types of global analyses. Additionally, this methodology can be applied in both fitting and interpolation modes, enabling the inclusion of additional information, such as integral constraints, tailored to the specific characteristics of different PDFs or data of different nature.

Speaker: Aurore Courtoy (Instituto de Física, UNAM)

CTEQ_winter_24_AC.pdf

10:00 Jets in DIS: Present and Future

I will provide an overview of recent jet measurements in DIS using data from the H1 experiment at HERA. Renewed interest, triggered by the upcoming EIC, has once again brought jet physics in DIS to the forefront of research. I will highlight how novel observables, algorithms, and theoretical frameworks developed in recent years have been tested against precise DIS data. Additionally, I will explore potential advancements that could arise from the EIC pathfinder program over the next decade. Finally, I will discuss future prospects at the EIC, where the next-generation of detector technology will enable a comprehensive jet physics program at the core scientific mission of the EIC.

Speaker: Miguel Arratia Munoz

Arratia.pdf

slides

VIRTUE Demo.mp4

10:30 → 11:00 Coffee break

11:00 → 12:30 Public Session

Extra non-structured time for discussions and follow-up chats.

11:00 QCD opportunities at JLab with 12 GeV positrons and 22 GeV Electrons

Speaker: Cynthia (Thia) Keppel

CTEQ_2024_Keppel.pdf

CTEQ_2024_Keppel.pptx

11:30 Towards a parton shower with next-to-leading order splitting functions

Parton shower event generators are based on approximations to what can be called a quantum parton shower evolution equation. The "quantum" designation indicates that the quantum nature of color and spin are incorporated. The splitting functions for this kind of shower evolution are currently known only to first order in the strong coupling. I will describe work to extend this to second order for the case of electron-positron annihilation.

Speaker: Prof. Davison Soper (University of Oregon)

12:00 Evidence for Modified Quark-Gluon Distributions in Nuclei by Correlated Nucleon Pairs

We extend the QCD Parton Model analysis using a factorized nuclear structure model incorporating individual nucleons and pairs of correlated nucleons. Our analysis of high-energy data from lepton Deep-Inelastic Scattering, Drell-Yan and W/Z production simultaneously extracts the universal effective distribution of quarks and gluons inside correlated nucleon pairs, and their nucleus-specific fractions. Such successful extraction of these universal distributions marks a significant advance in our understanding of nuclear structure properties connecting nucleon- and parton-level quantities.

Speaker: Prof. Fred Olness (Southern Methodist University (US))

OLNESS_CTEQ_NOV2024.pdf

12:20 Discussion

12:30 → 14:00 Lunch

14:00 → 15:30 Public Session

Extra non-structured time for discussions and follow-up chats.

14:00 Alpha strong determination with JLab experimental data

Speaker: Alexandre Deur (Jefferson Lab)

a_s_cteq24.pdf

14:30 Extraction of Parton Structure including Lattice QCD

QCD is a difficult theory of hadrons because it is described entirely unobservable partons, the quarks and gluons. In order to access parton distributions, hadronic observables such as experimental cross sections or lattice QCD matrix elements must have factorization approximations separated hadronic and partonic distance scales. These observables are sensitive to different regimes in momentum fraction x. This complementarity could be beneficial in extractions of PDFs, TMDs, and GPDs. In this talk I will highlight a few specific cases where modern lattice QCD can have significant impact.

Speaker: Dr Joseph Karpie (JLab)

Karpie_cteq_2024.pdf

14:50 Collins-Soper kernel from collinear factorization

Inclusive DIS at large Bjorken is revisited to highlight the importance of tracking off-lightcone effects in the proof of factorization theorems, even collinear ones. In DIS at threshold, in particular, the relevant physics develops around two opposite light-cone directions just like in TMD SIDIS, and the Collins Soper kernel emerges as a universal function in the rapidity evolution of the relevant correlators. The new factorization theorem thus offers a novel avenue for lattice calculations of the Collins-Soper kernel with collinear operators, and bridges different fields and communities.

Speaker: Matteo Cerutti (Christopher Newport University and Jefferson Lab)

CTEQ_Fall.pdf

15:10 Discussion

15:30 → 16:00 Coffee Break

16:00 → 17:30 Public Session

Extra non-structured time for discussions and follow-up chats.

16:00 GMVFN scheme implementations with Subtraction and Residual PDFs for processes at hadron colliders

We discuss the application of ACOT-like general mass
variable flavor number (GMVFN) schemes to proton-proton collisions with particular attention to the production of final states with at least one heavy quark. Subtraction and residual heavy-quark parton distribution functions are introduced to facilitate the implementation of this scheme at higher orders in perturbative QCD.

Speaker: Marco Guzzi (Kennesaw State University)

Subtraction-PDFs-Nov-21-2024.pdf

16:30 Fast NNLO Implementation of the approximate ACOT scheme for DIS

Mass-dependent quark contributions are of great importance to DIS processes. The simplified-ACOT-$\chi$ scheme includes these effects over a wide range of momentum transfers up to next-to-leading order in QCD. In recent years an improvement in the case of neutral current DIS has been achieved by using zero-mass contributions up to next-to-next-to-leading order (NNLO) with massive phase-space constraints. In this talk, we extend this approach to the case of charged current DIS and provide an implementation in the open-source code APFEL++. The increased precision will be valuable for understanding current and future neutrino experiments, the Electron-Ion-Collider and the studies of partonic substructure of hadrons and nuclei. A highly efficient implementation using gridding techniques extends the applicability of the code to the determination of parton distribution functions (PDFs).

Speaker: Peter Risse

Risse_CTEQ_fall_CNU.pdf

16:50 News from the CTEQ-TEA global analysis

I summarize the recent progress on the global PDF analysis for protons and pions from the CTEQ-TEA group, with the main focus on the results published in arXiv:2408.04020.

Speaker: Prof. Pavel Nadolsky (Southern Methodist University/Michigan State University)

ob20_cteq_mtg.pdf

17:10 Discussion

18:00 → 20:00 Public: Reception

Friday 22 November

08:30 → 09:00 Light breakfast

09:00 → 10:30 Public Session

Extra non-structured time for discussions and follow-up chats.

09:00 PVDIS investigations with SoLID detector

Speaker: Michael Nycz (University of Virginia)

CTEQ_2024_Mike.pdf

09:20 Impact of parity-violating deep-inelastic scattering on the nucleon strangeness and weak mixing angle

At present, there is a lack of experimental data constraining the dependence of the strange nucleon parton distribution functions (PDFs) on the parton momentum fraction and the electroweak mixing angle at low-$Q^2$. The parity-violating asymmetry from the neutral-current deep inelastic scattering of electrons from proton and deuterium targets, which will be measured by the proposed SoLID experiment at Jefferson Lab, possesses a known sensitivity to both the strange PDFs and electroweak parameters. In this work we explore this sensitivity and perform a new global analysis, incorporating pseudo-data from simulations based on SoLID experimental projections with radiative corrections to the asymmetry, for the unpolarized PDFs and the weak-mixing angle. We find a sizable constraining power of future $A_{PV}$ data on the high-$x$ behavior of the nucleon strangeness and a substantial resolving power on the weak-mixing angle at low-$Q^2$.

Speaker: Richard Whitehill

rwhitehill-CTf24.pdf

09:40 Pixelizing Quantum-Correlation Functions: A Novel Approach for Hadron Structure Studies

In this talk, we introduce a new approach for parameterizing Quantum-Correlation Functions (QCFs). By treating QCFs as multidimensional images or tensors, we propose a pixel-based representation. This novel perspective offers a versatile framework for analyzing and manipulating QCFs, enabling us to leverage a wide range of image processing techniques.

We will demonstrate the effectiveness of our new approach by applying it to extract Generalized Parton Distributios from Compton Form Factors. We will present initial results, showcasing its potential to enhance our understanding of hadron structure. Additionally, we will discuss the benefits of this method, such as its flexibility, and computational efficiency. By treating QCFs as images, we unlock new possibilities for research and analysis in hadron physics.

Speaker: Marco Zaccheddu (Jefferson Lab)

cteq_mz_.pdf

10:00 New Measurements of the Deuteron to Proton F2 Structure Function Ratio at Hall C, Jefferson Lab

Nucleon structure functions, measured in lepton-nucleon scattering, are key to understanding partonic dynamics. At high parton momenta, extracting parton distributions becomes challenging due to non-perturbative effects and limited precision data. Neutron structure and d-quark distributions are particularly difficult to extract due to nuclear corrections required for deuteron-based measurements. Recent experiments at Jefferson Lab, including E12-10-002 in Hall C, have significantly reduced these uncertainties by improving deuteron-to-proton cross-section measurements at large Bjorken-x. These results enhance precision and provide valuable insights for refining global parton distribution function fits.

Speaker: Debaditya Biswas (Virginia Tech)

CTEQ_FALL_2024_CNU_BISWAS_1.pdf

10:20 Discussion

10:30 → 11:00 Coffee Break

11:00 → 12:30 Public Session

Extra non-structured time for discussions and follow-up chats.

11:00 Systematic uncertainties from the implementation of higher twists in QCD analyses

Speaker: Sanghwa Park (Jefferson Lab)

CTEQmeeting2024_SPark.pdf

11:20 Uncertainty quantification with discrepant data sets

I will discuss different models of uncertainty quantification when different data sets of a fit disagree and are discrepant. Specifically I will review three different models including the use of the Gaussian Mixture Model to determine uncertainties.

Speaker: Kirtimaan Ajaykant Mohan

K_Mohan_CTEQ_Meeting_2024_11_21.pdf

11:40 Systematic uncertainties in PDF fits

We will discuss some aspects of the interpretation of systematic uncertainties in global PDF analyses

Speaker: Prof. Pavel Nadolsky (Southern Methodist University/Michigan State University)

ob22_systematic.pdf

12:10 Discussion

12:30 → 14:00 Group photo and lunch break