Thu·Sep 1, 2022Thursday·September 1, 2022

1. 01*

   $R$-dependence of inclusive jet suppression and groomed jet splittings in heavy-ion collisions with ALICE

   Hannah Bossi (for the ALICE Collaboration)🇺🇸

   Jets in relativistic heavy-ion collisions (HICs) interact with the quark-gluon plasma (QGP), leading to effects such as a suppression of jet yields and a modification of internal jet structure that are used to measure the properties of the QGP. These proceedings show the inclusive jet nuclear modification factors in Pb--Pb collisions in various centrality classes at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV recorded with the ALICE detector for resolution parameters up to $R$ = 0.6 for momenta down to 40 GeV/$c$. The analysis utilizes machine learning techniques to correct the large background in HICs, extending the measurement of inclusive jets to lower jet $p_T$ and larger $R$ than previously achieved in HICs at the LHC. A new suite of measurements characterizing groomed jet splittings using both the Soft Drop and Dynamical Grooming algorithms in central and semi-central Pb--Pb collisions will also be presented. The groomed jet radius, ${\theta }_{\mathrm{g}}\equiv R_{\mathrm{g}}/R$, the groomed jet momentum fraction, $z_{\mathrm{g}}$, and the transverse momentum of the groomed splitting, $k_{\mathrm{T},\mathrm{g}}$ are also reported. All measurements are fully corrected through unfolding and compared to various theoretical calculations.

   nucl-exActa Phys.Polon.Supp.(2023)·6 citations
2. 02*

   Elliptic and triangular flow of (multi-)strange hadrons and $\varphi$ mesons in BES-II energies at STAR

   Like Liu

   In these proceedings, we present the measurements of elliptic ($v_2$) and triangular ($v_3$) flow of (multi-)strange hadrons and $\varphi$ mesons in 19.6 and 14.6 GeV Au+Au collisions from STAR. The number of constituent quark (NCQ) scaling of $v_2$ and $v_3$ holds well at $\sqrt{s_{\mathrm{NN}}}$ = 19.6 GeV, which indicates the collective flow is built up in the partonic stage. At these energies, the anti-particles show better NCQ scaling than the particles for both $v_2$ and $v_3$, which may be caused by the different contributions from the produced and transported quarks.

   nucl-exhep-exEPJ Web Conf.(2023)·3 citations
3. 03*

   Overview of quarkonium production with ALICE at the LHC

   H. Hushnud🇮🇳

   ALICE is a general purpose experiment designed to investigate nucleus-nucleus collisions at the Large Hadron Collider (LHC), located at CERN. The ALICE detector is optimized for the reconstruction of quarkonia through the dimuon decay channel at foward rapidity as well as the dielectron decay channel at midrapidity. In this contribution, quarkonium measurements performed by the ALICE collaboration at both midrapidity and forward rapidity for various energies and colliding systems (pp, p-Pb and Pb-Pb), will be discussed and compared to theory.

   nucl-exSciPost Phys.Proc.(2023)·2 citations
4. 04*

   Detector Requirements and Simulation Results for the EIC Exclusive, Diffractive and Tagging Physics Program using the ECCE Detector Concept

   A. Bylinkin · C. T. Dean · S. Fegan · D. Gangadharan · K. Gates · S. J. D. Kay · I. Korover · W.B. Li · X. Li · R. Montgomery · D. Nguyen · G. Penman and 271 other authors

   This article presents a collection of simulation studies using the ECCE detector concept in the context of the EIC's exclusive, diffractive, and tagging physics program, which aims to further explore the rich quark-gluon structure of nucleons and nuclei. To successfully execute the program, ECCE proposed to utilize the detecter system close to the beamline to ensure exclusivity and tag ion beam/fragments for a particular reaction of interest. Preliminary studies confirmed the proposed technology and design satisfy the requirements. The projected physics impact results are based on the projected detector performance from the simulation at 10 or 100 fb^-1 of integrated luminosity. Additionally, a few insights on the potential 2nd Interaction Region can (IR) were also documented which could serve as a guidepost for the future development of a second EIC detector.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2023)·16 citations
5. 05*

   Towards three-dimensional nucleon structures at the Electron-Ion Collider in China: A study of the Sivers function

   Chunhua Zeng🇨🇳 · Tianbo Liu🇨🇳 · Peng Sun🇨🇳 · Yuxiang Zhao🇨🇳

   Transverse momentum-dependent parton distribution functions (TMDs) provide three-dimensional imaging of the nucleon in the momentum space. With its fundamental importance in understanding the spin structure of the nucleon, the precise measurement of TMDs is considered as one of the main physics topics of the proposed Electron-Ion Collider in China (EicC). In this paper, we investigate the impact of future semi-inclusive deep inelastic scattering (SIDIS) data from EicC on the extraction of TMDs. Taking the Sivers function as an example, we revisited the world SIDIS data, which serves as the input for the simulated EicC data. By performing a combined analysis of the world data and the EicC simulated data, we quantitatively demonstrate that the Sivers functions can be precisely determined for various quark flavors, especially for sea quarks, in the region, $x>0.005$, directly covered by the EicC.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2022)·15 citations
6. 06*

   Extraction of the Coulomb Sum Rule, Transverse Enhancement, and Longitudinal Quenching from an Analysis of all Available e-${}^{12}$C and e-${}^{16}$O Cross Section Data

   A. Bodek🇺🇸 · M. E. Christy🇺🇸

   We report on a phenomenological analysis of all available electron scattering data on ${}^{12}\mathrm{C}$ (about 6600 differential cross section measurements) and on ${}^{16}\mathrm{O}$ (about 250 measurements) within the framework of the quasielastic (QE) superscaling model (including Pauli blocking). All QE and inelastic cross section measurements are included down to the lowest momentum transfer $\mathbf{q}$ (including photo-production data). We find that there is enhancement of the transverse QE response function ($R_T^{QE}$) and quenching of the QE longitudinal response function ($R_L^{QE}$) at low $\mathbf{q}$ (in addition to Pauli blocking). We extract parameterizations of a $multiplicative$ low $\mathbf{q}$ "Longitudinal Quenching Factor" and an $additive$ "Transverse Enhancement" contribution. Additionally, we find that the excitation of nuclear states contribute significantly (up to 30\%) to the Coulomb Sum Rule $SL(\mathbf{q})$. We extract the most accurate determination of $SL(\mathbf{q})$ to date and find it to be in reasonable agreement with recent theoretical calculations.

   ↳ hep-phhep-exnucl-exnucl-thPRC(2022)·18 citations
7. 07*

   Applicability of Hydrodynamics in Hadronic Phase of Heavy-Ion Collisions

   Ronald Scaria🇮🇳 · Captain R. Singh🇮🇳 · Raghunath Sahoo🇮🇳

   The hadronic phase and its dynamics in relativistic heavy-ion collisions are topics of immense discussion. The hadronic phase contains various massive hadrons with an abundance of the lightest hadron, i.e., $\pi$-mesons (pions). In this paper, we consider that pions are in thermal equilibrium in the hadronic phase and use second-order viscous hydrodynamics for a medium of massive pions to obtain its expansion to the boundary of the kinetic freeze-out. We achieve the kinetic freeze-out boundary with the Knudsen number $Kn>1$ limit. When this condition is met, hydrodynamics expansion breaks down, and the mean free path becomes sufficiently large in comparison with the system size so that the particle yields are preserved. Further, we investigate the effect of the massive fluid on the resonance particle yields, including re-scattering and regeneration, along with the natural decay widths of the resonances. The resonances can play an essential role in determining the characteristics of the hadronic phase as they have sufficiently small lifetimes, which may be comparable to the hadronic phase lifetime. In the current study, we predict the hadronic phase lifetime, which is further used to determine the $K^{\ast }(892{)}^0/K$, $\varphi (1020)/K$, and $\rho (770{)}^0/\pi$ yield ratios at the kinetic freeze-out. We calculate these ratios as a function of charged particle multiplicity and transverse momentum and compare the findings with experimental data. Our calculations qualitatively agree with the experimental data, indicating a possible hydrodynamical evolution of the hadronic phase.

   ↳ hep-phhep-exnucl-exnucl-thPhysics(2025)·6 citations
8. 08*

   Dispersion-theoretical analysis of the electromagnetic form factors of the $\Lambda$ hyperon

   Yong-Hui Lin🇩🇪 · Hans-Werner Hammer🇩🇪 · Ulf-G. Meißner🇩🇪

   The electromagnetic form factors of the $\Lambda$ hyperon in the time-like region are determined precisely through a dispersion-theoretical analysis of the world data for the cross section of the annihilation process $e^{+}{e}^{-}\to \bar{\Lambda }\Lambda$. The spectral function is represented by a superposition of narrow and broad vector meson poles. We test different scenarios for the spectral function and obtain a good description of the world data in the time-like region. The uncertainties in the extracted form factors are estimated by means of the bootstrap sampling method. The analytical continuation of the form factors to the space-like region introduces large errors due to the lack of data. When the electric $\Lambda$ radius from chiral perturbation theory is taken as a constraint, the magnetic radius is predicted as $r_M=0.681\pm 0.002$ fm. We also extract various vector meson to baryon coupling constants.

   ↳ hep-phhep-exnucl-exnucl-thEPJC(2022)·12 citations
9. 09*

   Report on Progress in Physics: Observation of the Breit-Wheeler Process and Vacuum Birefringence in Heavy-Ion Collisions

   James Daniel Brandenburg🇺🇸 · Janet Seger🇺🇸 · Zhangbu Xu🇺🇸 · Wangmei Zha🇨🇳

   This Report reviews the effort over several decades to observe the linear Breit-Wheeler process ($\gamma \gamma \to e^{+}{e}^{-}$) and vacuum birefringence in high-energy particle and heavy-ion collider experiment. This Report, motivated by STAR's recent observations, attempts to summarize the key issues related to the interpretation of polarized $\gamma \gamma \to l^{+}{l}^{-}$ measurements in high-energy experiments. To that end, we start by reviewing the historical context and essential theoretical developments, before focusing on the decades of progress made in high-energy collider experiments. Special attention is given to the evolution in experimental approaches in response to various challenges and the demanding detector capabilities required to unambiguously identify the linear Breit-Wheeler process and to detect the signatures of vacuum birefringence. We close the report with a discussion, followed by a look at near-future opportunities for utilizing these discoveries and for testing QED in previously unexplored regimes.

   ↳ hep-phnucl-exnucl-thRept.Prog.Phys.(2023)·39 citations
10. 10*

    Studies of the linearity and stability of Silicon Drift Detectors for kaonic atoms X-ray spectroscopy

    A. Khreptak🇮🇹 · C. Amsler🇦🇹 · M. Bazzi🇮🇹 · D. Bosnar🇭🇷 · M. Bragadireanu🇷🇴 · M. Carminati🇮🇹 · M. Cargnelli🇦🇹 · A. Clozza🇮🇹 · G. Deda🇮🇹 · L. De Paolis🇮🇹 · R. Del Grande🇮🇹 · L. Fabbietti🇩🇪 and 27 other authors

    The SIDDHARTA-2 experiment at the DA$\Phi$NE collider aims to perform precision measurements of kaonic atoms X-ray spectroscopy for the investigation of the antikaon-nucleon strong interaction. To achieve this goal, novel large-area Silicon Drift Detectors (SDDs) have been developed. These devices have special geometry, field configuration and readout electronics that ensure excellent performance in terms of linearity and stability. The paper presents preliminary results for the linearity determination and stability monitoring of the SDDs system during the measurement of kaonic deuterium carried out in the summer of 2022.

    ↳ physics.ins-detnucl-exActa Phys.Polon.Supp.(2022)·0 citations
11. 11*

    Characterization of the new Ultracold Neutron beamline at the LANL UCN facility

    D. K.-T. Wong🇺🇸 · M. T. Hassan🇺🇸 · J. F. Burdine🇺🇸 · T. E. Chupp🇺🇸 · S. M. Clayton🇺🇸 · C. Cude-Woods🇺🇸 · S. A. Currie🇺🇸 · T. M. Ito🇺🇸 · C.-Y. Liu · M. Makela · C. L. Morris🇺🇸 · C. M. O'Shaughnessy🇺🇸 and 3 other authors

    The neutron electric dipole moment (nEDM) experiment that is currently being developed at Los Alamos National Laboratory (LANL) will use ultracold neutrons (UCN) and Ramsey's method of separated oscillatory fields to search for a nEDM. In this paper, we present measurements of UCN storage and UCN transport performed during the commissioning of a new beamline at the LANL UCN source and demonstrate a sufficient number of stored polarized UCN to achieve a statistical uncertainty of $\delta d_n=2\times 10^{-27}$~$e\cdot \text{cm}$ in 5 calendar years of running. We also present an analytical model describing data that provides a simple parameterization of the input UCN energy spectrum on the new beamline.

    ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2023)·10 citations

* 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.