Thu·Dec 18, 2025Thursday·December 18, 2025

1. 01*

   Observation of partonic collectivity via $p_{\mathrm{T}}$-differential radial flow fluctuations in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=200$ GeV

   Rohit Agarwala🇮🇳 · Dipankar Basak🇮🇳 · Kalyan Dey🇮🇳

   We report the observation of partonic radial collectivity in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=200$~GeV via the $p_{\mathrm{T}}$-differential flow observable $v_0(p_{\mathrm{T}})$ using the \texttt{AMPT} String Melting model. For inclusive charged hadrons, we establish three signatures of collectivity: long-range pseudorapidity correlations, the factorization of two-particle correlations, and a centrality-independent scaling of $v_0(p_{\mathrm{T}})$ normalized by its $p_{\mathrm{T}}$-integrated value $v_0$, analogous to anisotropic flow. For identified particles (${\pi }^{\pm },K^{\pm },p+\overline{p}$), the $v_0(p_{\mathrm{T}})$ spectra show mass ordering at low-$p_{\mathrm{T}}$ and meson-baryon separation at intermediate-$p_{\mathrm{T}}$. In \textit{central} collisions, $v_0(p_{\mathrm{T}})/n_q$ exhibits robust \textit{Number of Constituent Quark} (NCQ) scaling with $(m_{\mathrm{T}}-m_0)/n_q$, a scaling that breaks down in \textit{peripheral} collisions and is more precise at RHIC than at LHC energies, consistent with earlier $v_2$ studies. These findings provide strong evidence that radial collectivity originates predominantly at the partonic stage, extending the paradigm of quark-level dynamics from anisotropic to isotropic flow.

   nucl-exhep-ph1 citation
2. 02*

   Triplet of kindred prompt-2p emitters in mass-8 proton-rich nuclei

   R.J. Charity🇺🇸 · G.H. Sargsyan🇺🇸 · K.D. Launey🇺🇸 · T.B. Webb · K.W. Brown🇺🇸 · L.G. Sobotka🇺🇸

   A triplet of kindred prompt-2p emitters in A=8 nuclei has been demonstrated. Two of these are the ground state of 8C and its isobaric analog state in 8B, both of which are analogs of the halo or thick-skinned nucleus 8He. The third member is the recently found fourth 1+ state in 8B. This new 8B state at E*=8.4 MeV was observed to decay to the ground state of 6Li by 2p emission. Momentum correlations between the decay products indicate that it is not a sequential 2p decay through a 7Be intermediate state, but indicative of prompt 2p emission with correlations similar to those of the other members of the triplet. Ab initio calculations with the symmetry-adapted nocore shell model indicate that these three states have very similar spatial wavefunctions, but with nucleons coupling to different spins, isospins, and isospin projections. The triplet of 2p emitters all have oblate shapes and by stripping two protons equatorially, decay to states which have prolate shapes.

   nucl-exnucl-th1 citation
3. 03*

   ANUBIS: Projected Sensitivities and Initial Results from the proANUBIS demonstrator with Run 3 LHC data

   Théo Reymermier🇫🇷 · Oleg Brandt🇬🇧 · Anna Mullin🇬🇧 · Paul Swallow🇬🇧 · Michael Revering🇬🇧 · Cayetano Fernandez Ruiz🇬🇧

   Despite the success of the Standard Model (SM) there remains behaviour it cannot describe, in particular the presence of non-interacting Dark Matter. Many models that describe dark matter can generically introduce exotic Long-Lived Particles (LLPs). The proposed ANUBIS experiment is designed to search for these LLPs within the ATLAS detector cavern, located approximately 20-30 m from the Interaction Point (IP). A prototype detector, proANUBIS, has taken data within the ATLAS detector cavern since 2024, corresponding to 104 $f{b}^{-1}$ of pp data. We report on the potential sensitivity of ANUBIS to a selection of LLP models, i.e. Higgs Portal and Heavy Neutral Leptons, as well as future planned studies. Additionally, we will show the first results of the proANUBIS demonstrator, and how it will be used to study the expected backgrounds for the ANUBIS detector.

   ↳ hep-exhep-phnucl-exPoS(2026)·0 citations
4. 04*

   High voltage and electrode system for a cryogenic experiment to search for the neutron electric dipole moment

   M. A. Blatnik🇺🇸 · S. M. Clayton🇺🇸 · S. A. Currie🇺🇸 · B. W. Filippone🇺🇸 · M. Makela🇺🇸 · C. M. O'Shaughnessy🇺🇸 · N. S. Phan🇺🇸 · J. C. Ramsey🇺🇸 · G. V. Riley🇺🇸 · A. Roberts🇺🇸 · T. Sandborn🇺🇸 · T. J Schaub🇺🇸 and 7 other authors

   The cryogenic approach to the search for the neutron electric dipole moment--performing the experiment in superfluid liquid helium--holds promise for a substantial increase in sensitivity, potentially enabling a sensitivity level of $10^{-28}$ e-cm. A crucial component in realizing such an experiment is the high voltage and electrode system capable of providing an electric field of 75 kV/cm. This, in turn, requires an electric potential of 635 kV to be applied to the high voltage electrode, while simultaneously satisfying other experimental constraints, such as those on heat load and magnetic noise requirements. This paper describes the outcome of a comprehensive development program addressing these challenges. It outlines the system requirements, discusses new insights into relevant physical phenomena, and details selected technical solutions with their corresponding experimental demonstrations and expected performance. The results collectively demonstrate the successful development of the necessary technology for the high-voltage and electrode system for this approach.

   ↳ physics.ins-detnucl-exPRC(2026)·3 citations
5. 05*

   Three-dimensional imaging of hadrons with hard exclusive reactions: advances in experiment, theory, phenomenology, and lattice QCD

   M. Boër🇺🇸 · A. Camsonne🇺🇸 · M. Constantinou🇺🇸 · H.S. Jo🇰🇷 · K. Joo🇺🇸 · K. Semenov-Tian-Shansky🇰🇷 · H.-D. Son🇰🇷 · P. Sznajder🇵🇱 · C. Van Hulse🇪🇸 · E. Voutier🇫🇷 · J. Wagner🇵🇱 · A. Afanasev🇺🇸 and 28 other authors

   Generalized Parton Distributions (GPDs) have emerged as a powerful framework for exploring the internal structure of hadrons in terms of their partonic constituents. Over the past three decades, the field has witnessed significant theoretical and experimental advancements. The interpretation of GPDs in impact parameter space offers a vivid three-dimensional visualization of hadron structure, correlating longitudinal momentum and transverse spatial distributions, thereby enabling tomographic imaging of hadrons. Furthermore, the link between GPDs and the matrix elements of the QCD energy-momentum tensor provides access to fundamental properties of hadrons, including spin decomposition and internal pressure distributions. Notably, recent analyses of Deeply Virtual Compton Scattering (DVCS) data have enabled the empirical extraction of the quark pressure profile inside the proton. Motivated by the rapidly evolving experimental landscape, this white paper provides a timely and focused overview of recent developments in GPD theory, phenomenology, and lattice QCD studies. Its scope is shaped by the needs and opportunities of forthcoming experimental programs, and it highlights advances that are particularly relevant for the next generation of dedicated measurements, including the extended Jefferson Lab 12 GeV program and its potential 22 GeV upgrade, J-PARC, COMPASS/AMBER, LHC ultra-peripheral collisions, and the future electron-ion colliders EIC and EicC.

   ↳ hep-phhep-exhep-latnucl-ex+114 citations
6. 06*

   Weak Charge Form Factor Determination at the Electron-Ion Collider

   Hooman Davoudiasl🇺🇸 · Hongkai Liu🇺🇸 · Sonny Mantry🇺🇸 · Ethan T. Neil🇺🇸

   Determining the weak charge form factor, $F_W(Q^2)$, of nuclei over a continuous range of momentum transfers, $0\lesssim Q^2\lesssim 0.1$ GeV${}^2$, is essential for mapping out the distribution of neutrons in nuclei. The neutron density distribution has significant implications for a broad range of areas, including studies of nuclear structure, neutron stars, and physics beyond the Standard Model. Currently, our knowledge of $F_W(Q^2)$ comes primarily from fixed target experiments that measure the parity-violating asymmetry in coherent elastic electron-ion scattering. Fixed target experiments, such as CREX and PREX-1,2, have provided high-precision weak charge form factor extractions for the ${}^{48}\mathrm{Ca}$ and ${}^{208}\mathrm{Pb}$ nuclei, respectively. However, a major limitation of fixed target experiments is that they each provide data only at a single value of $Q^2$. With the proposed Electron-Ion Collider (EIC) on the horizon, we explore its potential to impact the determination of the weak charge form factor. While it cannot compete with the precision of fixed target experiments, it can provide data over a wide and continuous range of $Q^2$ values, and for a wide variety of nuclei. We show that with data corresponding to an integrated luminosity of $\mathcal{L}\sim$ 500/$A$ fb${}^{-1}$, where $A$ is the nucleus atomic weight, the EIC can significantly impact constraints by lifting degeneracies in theoretical models of the neutron density distribution. Ensuring EIC detector coverage at low $Q^2$ and large negative pseudorapidities will be essential for such $F_W(Q^2)$ measurements.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2026)·3 citations
7. 07*

   Two-proton emission as source of spin-entangled proton pairs

   Tomohiro Oishi🇯🇵 · Masaaki Kimura🇯🇵

   We show that a two-proton emitter with a diproton-correlated initial state can act as a source of spin-correlated proton pairs. Using a time-dependent three-body model, we investigate the two-proton emission of ${}^{16}$Ne (${}^{14}$O$+2p$) and analyze the spin correlation of the emitted protons. We find that, when the emission proceeds as a democratic three-body process from an initial state containing a spin-singlet diproton correlation, the emitted protons exhibit a pronounced spin-correlation pattern exceeding the local-hidden-variable bound. This spin correlation closely resembles that of a pure spin-singlet pair. In contrast, this pattern is lost when the process is dominated by the sequential emission or when the initial diproton correlation is absent. These results demonstrate that a certain class of two-proton emitters can deliver spin-entangled proton pairs, and their spin correlation reflects the diproton correlation embedded in the initial state.

   ↳ nucl-thnucl-exquant-phPLB(2026)·1 citation

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.