Wed·Nov 1, 2023Wednesday·November 1, 2023

1. 01*

   First measurement of kaonic helium-4 M-series transitions

   F Sgaramella🇮🇹 · D Sirghi🇮🇹 · L Abbene🇮🇹 · F Artibani🇮🇹 · M Bazzi🇮🇹 · D Bosnar🇭🇷 · M Bragadireanu🇷🇴 · A Buttacavoli🇮🇹 · M Cargnelli🇦🇹 · M Carminati🇮🇹 · A Clozza🇮🇹 · F Clozza🇮🇹 and 31 other authors

   In this paper we present the results of a new kaonic helium-4 measurement with a 1.37 g/l gaseous target by the SIDDHARTA-2 experiment at the DA{\Phi}NE collider. We measured, for the first time, the energies and yields of three transitions belonging to the Mseries. Moreover, we improved by a factor about three, the statistical precision of the 2p level energy shift and width induced by the strong interaction, obtaining the most precise measurement for gaseous kaonic helium, and measured the yield of the L{\alpha} transition at the employed density, providing a new experimental input to investigate the density dependence of kaonic atoms transitions yield.

   nucl-exJ.Phys.G(2024)·4 citations
2. 02*

   Collective phenomena study in small systems using the bulk of particle production in high-multiplicity pp collisions at $\sqrt{s}=$ 13 TeV with ALICE

   Rajendra Nath Patra (for the ALICE Collaboration)🇮🇹

   The heavy-ion collisions (A--A) at the Large Hadron Collider (LHC) energies have confirmed the production of the quark-gluon plasma (QGP), a new state of nuclear matter where quarks and gluons are deconfined. The light-flavour hadrons ($\pi$, K, p), constitute the bulk of the produced particles, carry useful information of the collision geometry, collective behaviour and thermal property of the QGP. The measurements of light-flavour hadron production in small collision systems (pp and p--A) at the LHC energies have shown the onset of collective phenomena (e.g. radial flow and long-range correlations) that resemble what is typically observed in nucleus-nucleus collisions and attributed to the formation of a deconfined system of quarks and gluons. The new results of the identified light-flavour particle production measured in high-multiplicity triggered pp collisions at $\sqrt{s}=13$~TeV of ALICE Run 2 will be presented in search of collective behaviour in small collision systems. The transverse momenta $p_{\mathrm{T}}$-spectra of the identified particles show hardening at the mid-$p_{\mathrm{T}}$. The mean transverse momenta ($⟨p_{\mathrm{T}}⟩$) are shown as a function of charged-particle multiplicity. The ratios of $p_{\mathrm{T}}$-spectra and the ratios of the integrated yields of kaon- and proton-to-pion are also presented and compared with published results.

   nucl-exhep-exPoS(2024)·2 citations
3. 03*

   Understanding the transverse-spherocity biased data from pp collisions at the LHC energies

   Antonio Ortiz🇲🇽 · Lizardo Valencia Palomo🇲🇽 · Victor Manuel Minjares Neriz🇲🇽

   The ALICE collaboration recently reported the mean transverse momentum as a function of charged-particle multiplicity for different pp-collisions classes defined based on the "jettiness" of the event. The event "jettiness" is quantified using transverse spherocity that is measured at midpseudorapidity ($|\eta |<0.8$) considering charged particles with transverse momentum within $0.15<p_{\mathrm{T}}<10$ GeV/$c$. Comparisons to PYTHIA 8 (tune Monash) predictions show a notable disagreement between the event generator and data for jetty events that increases as a function of charged-particle multiplicity. This paper reports on the origin of such a disagreement using PYTHIA 8 event generator. Since at intermediate and high $p_{\mathrm{T}}$ ($2<p_{\mathrm{T}}<10$ GeV/$c$), the spectral shape is expected to be modified by color reconnection or jets, their effects on the average $p_{\mathrm{T}}$ are studied. The results indicate that the origin of the discrepancy is the overpredicted multijet yield by PYTHIA 8 which increases with the charged particle multiplicity. This finding is important to understand the way transverse spherocity and multiplicity bias the pp collisions, and how well models like PYTHIA 8 reproduce those biases. The studies are pertinent since transverse spherocity is currently used as an event classifier by experiments at the LHC.

   ↳ hep-phnucl-exUniverse(2024)·6 citations
4. 04*

   Multiconfigurational time-dependent density functional theory for atomic nuclei: Technical and numerical aspects

   Petar Marević🇫🇷 · David Regnier🇫🇷 · Denis Lacroix🇫🇷

   The nuclear time-dependent density functional theory (TDDFT) is a tool of choice for describing various dynamical phenomena in atomic nuclei. In a recent study, we reported an extension of the framework - the multiconfigurational TDDFT (MC-TDDFT) model - that takes into account quantum fluctuations in the collective space by mixing several TDDFT trajectories. In this article, we focus on technical and numerical aspects of the model. We outline the properties of the time-dependent variational principle that is employed to obtain the equation of motion for the mixing function. Furthermore, we discuss evaluation of various ingredients of the equation of motion, including the Hamiltonian kernel, norm kernel, and kernels with explicit time derivatives. We detail the numerical methods for resolving the equation of motion and outline the major assumptions underpinning the model. A technical discussion is supplemented with numerical examples that consider collective quadrupole vibrations in ${}^{40}$Ca, particularly focusing on the issues of convergence, treatment of linearly dependent bases, energy conservation, and prescriptions for the density-dependent part of an interaction.

   ↳ nucl-thnucl-exquant-phEPJA(2024)·7 citations
5. 05*

   Hybrid Hadronization of Jet Showers from $e^{+}+e^{-}$ to $A+A$ with JETSCAPE

   Cameron Parker🇺🇸 · Aaron Angerami🇺🇸 · Ritu Arora🇺🇸 · Steffen Bass🇺🇸 · Shanshan Cao🇨🇳 · Yi Chen🇺🇸 · Raymond Ehlers🇺🇸 · Hannah Elfner🇩🇪 · Wenkai Fan🇺🇸 · Rainer J. Fries🇺🇸 · Charles Gale🇨🇦 · Yayun He🇨🇳 and 39 other authors

   In this talk we review jet production in a large variety of collision systems using the JETSCAPE event generator and Hybrid Hadronization. Hybrid Hadronization combines quark recombination, applicable when distances between partons in phase space are small, and string fragmentation appropriate for dilute parton systems. It can therefore smoothly describe the transition from very dilute parton systems like $e^{+}+e^{-}$ to full $A+A$ collisions. We test this picture by using JETSCAPE to generate jets in various systems. Comparison to experimental data in $e^{+}+e^{-}$ and $p+p$ collisions allows for a precise tuning of vacuum baseline parameters in JETSCAPE and Hybrid Hadronization. Proceeding to systems with jets embedded in a medium, we study in-medium hadronization for jet showers. We quantify the effects of an ambient medium, focusing in particular on the dependence on the collective flow and size of the medium. Our results clarify the effects we expect from in-medium hadronization of jets on observables like fragmentation functions, hadron chemistry and jet shape.

   ↳ hep-phnucl-exnucl-thPoS(2024)·3 citations
6. 06*

   Superallowed nuclear beta decays and precision tests of the Standard Model

   Mikhail Gorchtein🇩🇪 · Chien Yeah Seng🇺🇸

   For many decades, the main source of information on the top-left corner element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix $V_{ud}$ were superallowed nuclear beta decays with an impressive 0.01\% precision. This precision, apart from experimental data, relies on theoretical calculations in which nuclear structure-dependent effects and uncertainties play a prime role. This review is dedicated to a thorough reassessment of all ingredients that enter the extraction of the value of $V_{ud}$ from experimental data. We tried to keep balance between historical retrospect and new developments, many of which occurred in just five past years. They have not yet been reviewed in a complete manner, not least because new results are a-coming. This review aims at filling this gap and offers an in-depth yet accessible summary of all recent developments.

   ↳ nucl-thhep-phnucl-exAnn.Rev.Nucl.Part.Sci.(2024)·34 citations
7. 07*

   The Beta-decay Paul Trap Mk IV: Design and commissioning

   L. Varriano (1 and 2)🇺🇸 · G. Savard (1 and 2)🇺🇸 · J. A. Clark (2 and 3) · D. P. Burdette (2)🇺🇸 · M. T. Burkey (4) · A. T. Gallant (4)🇺🇸 · T. Y. Hirsh (5) · B. Longfellow (4)🇺🇸 · N. D. Scielzo (4)🇺🇸 · R. Segel (6)🇺🇸 · E. J. Boron III (7) · M. Brodeur (8)🇺🇸 and 20 other authors

   The Beta-decay Paul Trap is an open-geometry, linear trap used to measure the decays of ${}^8$Li and ${}^8$B to search for a tensor contribution to the weak interaction. In the latest ${}^8$Li measurement of Burkey et al. (2022), $\beta$ scattering was the dominant experimental systematic uncertainty. The Beta-decay Paul Trap Mk IV reduces the prevalence of $\beta$ scattering by a factor of 4 through a redesigned electrode geometry and the use of glassy carbon and graphite as electrode materials. The trap has been constructed and successfully commissioned with ${}^8$Li in a new data campaign that collected 2.6 million triple coincidence events, an increase in statistics by 30% with 4 times less $\beta$ scattering compared to the previous ${}^8$Li data set.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2024)·2 citations
8. 08*

   Light-yield response of liquid scintillators using 2--6 MeV tagged neutrons

   N. Mauritzson · K.G. Fissum · J.R.M. Annand · H. Perrey · R. Al Jebali · A. Backis · R. Hall-Wilton · K. Kanaki · V. Maulerova-Subert · F. Messi · R.J.W. Frost · E. Rofors · J. Scherzinger

   Knowledge of the neutron light-yield response is crucial to the understanding of scintillator-based neutron detectors. In this work, neutrons from 2--6 MeV have been used to study the scintillation light-yield response of the liquid scintillators NE 213A, EJ 305, EJ 331 and EJ 321P using event-by-event waveform digitization. Energy calibration was performed using a GEANT model to locate the edge positions of the Compton distributions produced by gamma-ray sources. The simulated light yield for neutrons from a PuBe source was compared to measured recoil proton distributions, where neutron energy was selected by time-of-flight. This resulted in an energy-dependent Birks parametrization to characterize the non-linear response to the lower energy neutrons. The NE 213A and EJ 305 results agree very well with existing data and are reproduced nicely by the simulation. New results for EJ 331 and EJ 321P, where the simulation also reproduces the data well, are presented.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2024)·0 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.