Tue·Jun 6, 2023Tuesday·June 6, 2023

1. 01*

   133In: A Rosetta Stone for decays of r-process nuclei

   Z. Y. Xu🇺🇸 · M. Madurga🇺🇸 · R. Grzywacz🇺🇸 · T. T. King🇺🇸 · A. Algora🇪🇸 · A. N. Andreyev🇬🇧 · J. Benito🇪🇸 · T. Berry🇬🇧 · M. J. G. Borge🇪🇸 · C. Costache🇷🇴 · H. De Witte🇧🇪 · A. Fijalkowska🇵🇱 and 37 other authors

   The $\beta$ decays from both the ground state and a long-lived isomer of ${}^{133}$In were studied at the ISOLDE Decay Station (IDS). With a hybrid detection system sensitive to $\beta$, $\gamma$, and neutron spectroscopy, the comparative partial half-lives (logft) have been measured for all their dominant $\beta$-decay channels for the first time, including a low-energy Gamow-Teller transition and several First-Forbidden (FF) transitions. Uniquely for such a heavy neutron-rich nucleus, their $\beta$ decays selectively populate only a few isolated neutron unbound states in ${}^{133}$Sn. Precise energy and branching-ratio measurements of those resonances allow us to benchmark $\beta$-decay theories at an unprecedented level in this region of the nuclear chart. The results show good agreement with the newly developed large-scale shell model (LSSM) calculations. The experimental findings establish an archetype for the $\beta$ decay of neutron-rich nuclei southeast of ${}^{132}$Sn and will serve as a guide for future theoretical development aiming to describe accurately the key $\beta$ decays in the rapid-neutron capture (r-) process.

   nucl-exnucl-thPRL(2023)·12 citations
2. 02*

   Constraints on the decay of ${}^{180m}$Ta

   I.J. Arnquist · F.T. Avignone III · A.S. Barabash · C.J. Barton · K.H. Bhimani · E. Blalock · B. Bos · M. Busch · M. Buuck · T.S. Caldwell · C.D. Christofferson · P.-H. Chu and 47 other authors

   ${}^{180m}$Ta is a rare nuclear isomer whose decay has never been observed. Its remarkably long lifetime surpasses the half-lives of all other known $\beta$ and electron capture decays due to the large K-spin differences and small energy differences between the isomeric and lower energy states. Detecting its decay presents a significant experimental challenge but could shed light on neutrino-induced nucleosynthesis mechanisms, the nature of dark matter and K-spin violation. For this study, we repurposed the MAJORANA DEMONSTRATOR, an experimental search for the neutrinoless double-beta decay of ${}^{76}$Ge using an array of high-purity germanium detectors, to search for the decay of ${}^{180m}$Ta. More than 17 kilograms, the largest amount of tantalum metal ever used for such a search was installed within the ultra-low background detector array. In this paper we present results from the first year of Ta data taking and provide an updated limit for the ${}^{180m}$Ta half-life on the different decay channels. With new limits up to 1.5 x $10^{19}$ years, we improved existing limits by one to two orders of magnitude. This result is the most sensitive search for a single $\beta$ and electron capture decay ever achieved.

   nucl-exhep-exPRL(2023)·30 citations
3. 03*

   Isomeric excitation energy for ${}^{99}$In${}^m$ from mass spectrometry reveals constant trend next to doubly magic ${}^{100}$Sn

   L. Nies (1 and 2)🇨🇭 · D. Atanasov (1 and 3)🇨🇭 · M. Athanasakis-Kaklamanakis (1 and 4)🇨🇭 · M. Au (1 and 5)🇨🇭 · K. Blaum (6)🇩🇪 · J. Dobaczewski (7 and 8)🇬🇧 · B. S. Hu (9)🇨🇦 · J. D. Holt (9 and 10)🇨🇦 · J. Karthein (11)🇺🇸 · I. Kulikov (12)🇩🇪 · Yu. A. Litvinov (12 and 13)🇩🇪 · D. Lunney (14)🇫🇷 and 7 other authors

   The excitation energy of the 1/2${}^{-}$ isomer in ${}^{99}$In at $N=50$ is measured to be 671(37) keV and the mass uncertainty of the 9/2${}^{+}$ ground state is significantly reduced using the ISOLTRAP mass spectrometer at ISOLDE/CERN. The measurements exploit a major improvement in the resolution of the multi-reflection time-of-flight mass spectrometer. The results reveal an intriguing constancy of the $1/2^{-}$ isomer excitation energies in neutron-deficient indium that persists down to the $N=50$ shell closure, even when all neutrons are removed from the valence shell. This trend is used to test large-scale shell model, \textit{ab initio}, and density functional theory calculations. The models have difficulties describing both the isomer excitation energies and ground-state electromagnetic moments along the indium chain.

   nucl-exnucl-thPRL(2023)·22 citations
4. 04*

   Spectrum averaged cross section measurements of lutetium using standard 252Cf neutron source

   Martin Schulc🇨🇿 · Michal Kostal🇨🇿 · Tomas Czakoj · Evzen Novak · Jan Simon · Nella Hynkova · Roberto Capote🇦🇹

   The spectrum averaged cross section (SACS) in standard neutron field is a preferable tool for cross section validation. There are very few measurements involving lutetium neutron cross sections. The presented work uses only neutron standard, i.e., 252Cf(sf) neutron field, for validation of lutetium threshold cross sections. SACS were inferred from gamma spectrometry derived reaction rates. The SACS which were derived include 175Lu(n,2n)174Lu, 175Lu(n,3n)173Lu, 175Lu(n,p)175Yb, and 176Lu(n,n)176m1Lu reactions. All these reactions SACS were measured for the first time. MCNP6 calculations using JEFF-3.3 or ENDF/B-VIII.0 libraries for lutetium cross sections were compared with experimental data. The agreement was found very poor for all reactions under study. Thus there is a need for their improvement. The presented data can be also used for validation of the various theoretical models.

   nucl-exAppl.Radiat.Isot.(2022)·0 citations
5. 05*

   Recent $J/\psi$ results measured with PHENIX

   T. Novák (for the PHENIX Collaboration)🇭🇺

   Finalized PHENIX results are presented on $J/\psi$ modification from the RHIC system-size scan, which include $p$+Al, $p$+Au, and ${}^3$He+Au (small systems) collisions as well as $AA$ (large systems) collisions at forward and backward rapidity ($1.2<|y|<2.2$). Comparisons with state-of-the-art theory calculations and LHC data will be discussed. The forward rapidity data in small systems are well described by model calculations for all three systems, however, the backward rapidity $p$+Au and ${}^3$He+Au data are not reproduced by the shadowing calculation alone. $J/\psi$ $v_2$ meausrements in Au+Au collisions at forward rapidity is consistent with zero.

   nucl-exhep-ex0 citations
6. 06*

   Measurement of Dosimetrical Cross Sections with 14.05 MeV Neutrons From Compact Neutron Generator

   Michal Kostal🇨🇿 · Tomáš Czakoj · Jan Simon · Marek Zmeskal🇨🇿 · Martin Schulc🇨🇿 · Alena Krechlerova · Tomáš Peltan · Filip Mravec · Frantisek Cvachovec · Vojtěch Rypar · Radim Uhlar · Petr Alexa · Ondrej Harkut · Zdenek Matej

   Dosimetry cross sections are fundamental quantities necessary for neutron dosimetry using the neutron activation method. It is worth noting that the uncertainty in cross sections is the major source of uncertainty in calculational predictions using nuclear data in simulations thus, cross section validation is a key issue in any aims for refinement of any predictions. A small compact neutron generator is a promising tool for performing integral experiments and even for differential experiments. This paper deals with the measurement of the differential dosimetry cross sections using a small compact D-T neutron generator with 14.05 MeV neutron emission (10E8 n/s into 4pi). Achieving measurable activation at such a low flux field is allowed by using a larger amount of activation material placed in close measurement geometry during decay gamma measurement. The experimentally determined cross sections are in good agreement with the cross sections in the IRDFF-II dosimetry library. The comparison with other nuclear data libraries was performed as well. Its worth noting, the mean standard deviation in IRDFF-II library is about 4 %, while in case of other data libraries they are from 5.5 % - 7.5 %. This result can be understood as a validation of IRDFF-II using 14.05 MeV neutrons and also a confirmation of the applicability of small compact generators in the measurement of activation cross sections.

   nucl-ex0 citations
7. 07*

   Impact of Reactor Neutron Spectrum on Measured Spectrum Averaged Cross Sections

   Michal Kostal🇨🇿 · Evzen Losa · Stanislav Simakov · Martin Schulc🇨🇿 · Jan Simon · Vojtech Rypar · Martin Mareček · Jan Uhlíř · Tomáš Czakoj · Andrej Trkov🇬🇧 · Roberto Capote🇦🇹

   The cross section averaged over 235U thermal-neutron induced fission spectrum is a fundamental quantity that can be used in evaluation and validation of nuclear data. Many experiments focused on the determination of Spectrum Averaged Cross Sections (SACS) in 235U(nth,f). Prompt Fission Neutron Spectrum (PFNS) in light water reactors using enriched uranium fuel. In these reactors, there is already some amount of water moderator between the uranium fuel and the irradiated sample. Due to the decrease of hydrogen cross-section with neutron energy, the high energy tail of the reactor spectrum in cores with water moderator may be harder than the pure PFNS. This paper aims to compare the shape of the actual reactor spectrum in various core positions of a research light-water reactor differing each from other by the effective water thickness. The spectrum shape is determined both by calculations and experimentally using various high energy threshold reactions. The impact of the photo-nuclear reactions ({\gamma},n) competing with (n,2n) in production of the same residual nucleus was shown to be less than a percent for most of studied dosimeters. An important exception was found for 197Au(n,2n) 196Au dosimeter irradiated in the outcore channel where a notable photo-neutron contribution to the production of 196Au is caused by the neutron production from the high energy {\gamma}-rays from thermal-neutron capture in 54Fe. The corresponding ENDF/B-VIII.0 data turned out to underestimate such {\gamma}-yield by 40% in comparison with ENDF/B-VI.8. This has improved but however not resolved the disagreement between our measurement and calculations. The remaining deficiency was attributed to the underestimation of the evaluated cross section IAEA/PD-2019 for the 197Au({\gamma},n) cross section near the reaction threshold. The later was confirmed by comparison with existing measured data.

   nucl-ex0 citations
8. 08*

   Validation of IRDFF-II library in VR-1 reactor field using thin targets

   Michal Kostal🇨🇿 · Evzen Losa1 · Martin Schulc🇨🇿 · Jan Simon · Tomas Bily · Vojtech Rypar · Martin Mareček · Jan Uhlíř · Tomáš Czakoj · Roberto Capote🇦🇹 · Andrej Trkov🇬🇧 · Stanislav Simakov

   Cross section data are fundamental quantities which affect the accuracy of all calculations in nuclear applications. A new dosimetry library IRDFF-II that contains cross section evaluations with full uncertainty quantification was developed by the International Atomic Energy Agency and released in January 2020 (https://www-nds.iea.org/IRDFF). A previous version, IRDFF-1.05, was released in 2014 and experimental validation of the newly released cross section by spectrum averaged cross section (SACS) measurements is a high priority task. For such purpose, a neutron dosimeter set containing 5 target foils was activated in 2 independent experiments at the VR-1 reactor of the Czech Technical University in Prague. Care was taken to derive SACS with low uncertainties. New experimental evaluation method is in good agreement with previous approaches based on relative measurements using monitor foils. Good agreement of measured SACS and evaluated IRDFF-II cross sections is observed. Slight overestimation of evaluated ENDF/B-VIII.0 235U(nth,f) PFNS above 10 MeV is discussed.

   nucl-exphysics.ins-det0 citations
9. 09*

   Shell model study of first-forbidden beta decay around ${}^{208}$Pb

   P. C. Srivastava🇮🇳 · S. Sharma🇨🇦 · A. Kumar🇮🇳 · P. Choudhary

   In the present work, we report a systematic theoretical study of the $\log ft$ values for the forbidden ${\beta }^{-}$ decay transitions in the ${}^{208}$Pb region. For this, we have considered ${}^{206}$Hg $\to$ ${}^{206}$Tl, ${}^{208}$Hg $\to$ ${}^{208}$Tl, ${}^{206}$Tl $\to$ ${}^{206}$Pb and ${}^{208}$Tl $\to$ ${}^{208}$Pb transitions. We have performed shell model calculations using KHH7B interaction in valence shell 58-114 for protons and 100-164 for neutrons by considering $1p-1h$ excitations for both protons and neutrons simultaneously for daughter nuclei. This study presents the first shell model results of ${\beta }^{-}$-decay corresponding to the recent experimental data.

   ↳ nucl-thnucl-exJ.Phys.Conf.Ser.(2023)·4 citations
10. 10*

    Heavy-flavor transport and hadronization in pp collisions

    Andrea Beraudo🇮🇹 · Arturo De Pace🇮🇹 · Daniel Pablos🇮🇹 · Francesco Prino🇮🇹 · Marco Monteno🇮🇹 · Marzia Nardi🇮🇹

    Recent experimental results on the Lambda_c/D^0 ratio in proton-proton collisions have revealed a significant enhancement compared to expectations based on universal fragmentation fractions/functions across different colliding systems, from e+e- to pp. This unexpected enhancement has sparked speculation about the potential effects of a deconfined medium impacting hadronization, previously considered exclusive to heavy-ion collisions. In this study, we propose a novel approach that assumes the formation of a small, deconfined, and expanding fireball even in pp collisions, where charm quarks can undergo rescattering and hadronization. We make use of the same in-medium hadronization mechanism developed for heavy-ion collisions, which involves local color-neutralization through recombination of charm quarks with nearby opposite color charges from the background fireball. Our model incorporates the presence of diquark excitations in the hot medium, which promotes the formation of charmed baryons. Moreover, the recombination process, involving closely aligned partons from the same fluid cell, effectively transfers the collective flow of the system to the final charmed hadrons. We show that this framework can qualitatively reproduce the observed experimental findings in heavy-flavor particle-yield ratios, $p_T$-spectra and elliptic-flow coefficients. Our results provide new, complementary supporting evidence that the collective phenomena observed in small systems naturally have the same origin as those observed in heavy-ion collisions

    ↳ hep-phhep-exnucl-exnucl-thPRD(2024)·43 citations
11. 11*

    The alpha and helion particle charge radius difference from spectroscopy of quantum-degenerate helium

    Y. van der Werf · K. Steinebach · R. Jannin · H.L. Bethlem · K.S.E. Eikema

    Accurate spectroscopic measurements of calculable systems provide a powerful method for testing the Standard Model and extracting fundamental constants. Recently, spectroscopic measurements of finite nuclear size effects in normal and muonic hydrogen resulted in unexpectedly large adjustments of the proton charge radius and the Rydberg constant. We measured the $2^3\mathrm{S}\to 2^1\mathrm{S}$ transition frequency in a Fermi gas of ${}^3$He with an order of magnitude higher accuracy than before. Together with a previous measurement in a ${}^4$He Bose-Einstein condensate, a squared charge radius difference $r_h^2-r_{\alpha }^2=1.0757(15)\mathrm{f}{\mathrm{m}}^2$ is determined between the helion and alpha particle. This measurement provides a benchmark with unprecedented accuracy for nuclear structure calculations. A deviation of 3.6$\sigma$ is found with a determination (arXiv:2305.11679) based on spectroscopy of muonic helium ions.

    ↳ physics.atom-phnucl-ex12 citations
12. 12*

    Using Cosmic Ray Muons to Assess Geological Characteristics in the Subsurface

    Harish R Gadey🇺🇸 · Robert Howard🇺🇸 · Stefano C Tognini🇺🇸 · Jennifer L Meszaros🇺🇸 · Rose A Montgomery🇬🇧 · Stylianos Chatzidakis🇺🇸 · JungHyun Bae🇺🇸 · Robert Clark🇺🇸

    Cosmic rays are energetic nuclei and elementary particles that originate from stars and intergalactic events. The interaction of these particles with the upper atmosphere produces a range of secondary particles that reach the surface of the earth, of which muons are the most prominent. With enough energy, muons can travel up to a few kilometers beneath the surface of the earth before being stopped completely. The terrestrial muon flux profile and associated zenith angle can be utilized to determine geological characteristics of a location without having to use conventional methods. This work intends to use a low-power plastic scintillator-based muon detection system for this non-destructive geological assay methodology. 4 custom designed plastic scintillation panels are used to realize two orthogonal detection planes. Simultaneous triggers between detectors from two planes indicate a coincidence event which is recorded using a data acquisition system from FNAL. In order to quantify the systematic uncertainties associated with the detector, such as energy depositions and angular resolution of the detector design, a Monte Carlo simulation using Geant4 is being developed. Simulated and experimental data will drive the development and validation of a reconstruction algorithm that, upon completion, is expected to predict average overburden and rock density. Extended detector exposure to muons can be used as a means to understand changes in the surrounding environment like rock porosity. On the experimental front, the measured flux data will be used to benchmark independent and established models. Successful proof-of-concept demonstration of this technology can open doors for long term non-invasive geological monitoring. The detector design, and experimental methodology are detailed in this work.

    ↳ physics.ins-dethep-exnucl-ex0 citations
13. 13*

    Normal single-spin asymmetries in electron-proton scattering: two-photon exchange with intermediate state resonances

    Jaseer Ahmed🇧🇩 · P. G. Blunden🇨🇦 · W. Melnitchouk🇺🇸

    We calculate the beam ($B_n$) and target ($A_n$) normal single-spin asymmetries in electron-proton elastic scattering from two-photon exchange amplitudes with resonance intermediate states of spin-parity $1/2^{\pm }$ and $3/2^{\pm }$ and mass $W\lesssim 1.8$ GeV. The latest CLAS exclusive meson electroproduction data are used as input for the transition amplitudes from the proton to the excited resonance states. For $B_n$, the spin 3/2 resonances dominate by an order of magnitude over the spin 1/2 states. In general we observe cancellations between the negative contributions of the $\Delta (1232)$ and $N(1520)$ across both beam energy and scattering angle, and the positive contributions of the $\Delta (1700)$ and $N(1720)$, leading to a rather large overall uncertainty band in the total $B_n$. At forward angles and beam energies $E_{\text{lab}}<1$ GeV, where the $\Delta (1232)$ dominates, the calculated $B_n$ tend to overshoot the A4 and SAMPLE data. The calculated $B_n$ compare well with the measured values from the A4 and $Q_{\text{weak}}$ experiments with $E_{\text{lab}}>1$ GeV.

    ↳ hep-phnucl-exnucl-thPRC(2023)·11 citations
14. 14*

    Environmental sustainability in basic research: a perspective from HECAP+

    Sustainable HECAP+ Initiative: Shankha Banerjee · Thomas Y. Chen · Claire David · Michael Düren · Harold Erbin · Jacopo Ghiglieri · Mandeep S. S. Gill · L Glaser · Christian Gütschow · Jack Joseph Hall · Johannes Hampp · Patrick Koppenburg and 14 other authors

    The climate crisis and the degradation of the world's ecosystems require humanity to take immediate action. The international scientific community has a responsibility to limit the negative environmental impacts of basic research. The HECAP+ communities (High Energy Physics, Cosmology, Astroparticle Physics, and Hadron and Nuclear Physics) make use of common and similar experimental infrastructure, such as accelerators and observatories, and rely similarly on the processing of big data. Our communities therefore face similar challenges to improving the sustainability of our research. This document aims to reflect on the environmental impacts of our work practices and research infrastructure, to highlight best practice, to make recommendations for positive changes, and to identify the opportunities and challenges that such changes present for wider aspects of social responsibility.

    ↳ physics.soc-phastro-ph.COgr-qchep-ph+1JINST(2025)·13 citations
15. 15*

    Measurements of ${\pi }^{+}$, ${\pi }^{-}$, $p$, $\bar{p}$, $K^{+}$ and $K^{-}$ production in 120 GeV/$c$ p + C interactions

    H. Adhikary · P. Adrich · K.K. Allison · N. Amin · E.V. Andronov · T. Antićić · I.-C. Arsene · M. Bajda · Y. Balkova · M. Baszczyk · D. Battaglia · A. Bazgir and 143 other authors

    This paper presents multiplicity measurements of charged hadrons produced in 120 GeV/$c$ proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment during two different data-taking periods, with increased phase space coverage in the second configuration due to the addition of new subdetectors. Particle identification via $dE/dx$ was employed to obtain double-differential production multiplicities of ${\pi }^{+}$, ${\pi }^{-}$, $p$, $\bar{p}$, $K^{+}$ and $K^{-}$. These measurements are presented as a function of laboratory momentum in intervals of laboratory polar angle covering the range from 0 to 450 mrad. They provide crucial inputs for current and future long-baseline neutrino experiments, where they are used to estimate the initial neutrino flux.

    ↳ hep-exnucl-exPRD(2023)·13 citations
16. 16*

    Effective field theory for radiative corrections to charged-current processes I: Vector coupling

    Vincenzo Cirigliano🇺🇸 · Wouter Dekens🇺🇸 · Emanuele Mereghetti🇺🇸 · Oleksandr Tomalak🇺🇸

    We study radiative corrections to low-energy charged-current processes involving nucleons, such as neutron beta decay and (anti)neutrino-nucleon scattering within a top-down effective-field-theory approach. We first match the Standard Model to the low-energy effective theory valid below the weak scale and, using renormalization group equations with anomalous dimensions of $\mathcal{O}(\alpha ,\alpha {\alpha }_s,{\alpha }^2)$, evolve the resulting effective coupling down to the hadronic scale. Here, we first match to heavy-baryon chiral perturbation theory and subsequently, below the pion-mass scale, to a pionless effective theory, evolving the effective vector coupling with anomalous dimensions of $\mathcal{O}(\alpha ,{\alpha }^2)$ all the way down to the scale of the electron mass, relevant for beta decays. We thus provide a new evaluation of the ``inner" radiative corrections to the vector coupling constant and to the neutron decay rate, discussing differences with the previous literature. Using our new result for the radiative corrections, we update the extraction of the Cabibbo-Kobayashi-Maskawa matrix element $V_{ud}$ from the neutron decay.

    ↳ hep-phhep-exhep-latnucl-ex+1PRD(2023)·71 citations
17. 17*

    The methodology for validation of cross sections in quasi monoenergetic neutron field

    Zdeněk Matěj · Michal Košťál🇨🇿 · Mitja Majerle · Martin Ansorge🇨🇿 · Evžen Losa · Marek Zmeškal🇨🇿 · Martin Schulc🇨🇿 · Jan Šimon · Milan Štefánik🇨🇿 · Jan Novák · Daniil Koliadko · František Cvachovec and 6 other authors

    Dosimetry cross sections are fundamental quantities essential in determination of neutron fluences in points of interest in technologies under heavy radiation load. The most common is their application to Reactor Pressure Vessel aging management, relating to correct estimation of its residual lifetime. The neutron spectrum in various reactor positions has a similar character as the fission spectrum. Due to this fact, the validation of the neutron dosimetry cross sections in reactor fields, or in a very well-known neutron field of 252Cf(s.f.) is sufficient for ensuring their validity in estimations of neutron fluxes in reactor physics. With an increasing field of applications, as in neutron dosimetry in accelerator-based fields or space applications, requests occurred on detailed validation in spectra different from fission ones. This paper presents the testing of a new methodology for the use of quasi monoenergetic neutron fields, where different sensitivity allows validations of the cross-section in different energy regions than in the fission spectrum. The exact shape of the neutron spectrum in the tested fields is determined by stilbene spectrometry and corrected to scattering by calculation, where applicable. The total flux is determined from Ni and Al flux monitors. The evaluated neutron flux in the target set of activation foils is used for calculation of theoretical reaction rate, which is compared with the experimental value determined from gamma activity. This kind of comparison can be understood as validation. It is worth noting, this methodology applied to the IRDFF-II library shows satisfactory agreement for selected reactions.

    ↳ physics.ins-detnucl-exphysics.acc-phNucl.Instrum.Meth.A(2022)·5 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.