Tue·Jun 18, 2024Tuesday·June 18, 2024

1. 01*

   An experimental search for an explanation of the difference between beam and bottle neutron lifetime measurements

   M. F. Blatnik🇺🇸 · L. S. Blokland🇺🇸 · N. Callahan🇺🇸 · J. H. Choi🇺🇸 · S. Clayton🇺🇸 · C. B Cude-Woods🇺🇸 · B. W. Filippone🇺🇸 · W. R. Fox🇺🇸 · E. Fries🇺🇸 · P. Geltenbort🇫🇷 · F. M. Gonzalez🇺🇸 · L. Hayen🇺🇸 and 23 other authors

   The past two decades have yielded several new measurements and reanalysis of older measurements of the neutron lifetime. These have led to a 4.4 standard deviation discrepancy between the most precise measurements of the neutron decay rate producing protons in cold neutron beams and the most precise lifetime measured in neutron storage experiments. Here we publish an analysis of the recently published UCN aimed a searching for an explanation of this difference using the model proposed by Koch and Hummel.

   nucl-ex4 citations
2. 02*

   Polarized internal target experiments based on EIC beams

   B. Wojtsekhowski🇺🇸

   The Electron-Ion Collider is under construction at BNL. It will have high-energy high-intensity polarized beams of electrons and hadrons. These beams will allow a high accuracy investigation of nucleon structure in the low- to very-low-x DIS regime. At the same time, similar to the realization at HERA, these beams could be used with an internal target for a very productive investigation of medium- to high-x nucleon structure. Due to a novel regime of electron beam operation and its high polarization and intensity, the Figure-of-Merit of an internal target experiment at EIC will be 500+ times higher than was obtained by HERMES.

   nucl-exPoS(2024)·0 citations
3. 03*

   Spinning Hall Probe magnetic compass

   B. Wojtsekhowski🇺🇸

   In a large range of physics and space experiments, the direction of the magnetic field needs to be determined with an accuracy on the level of one milli radian or better. We have proposed a new type of magnetic compass - a rotation-based one, which provides an alternating signal from the Hall probe proportional to the value of the magnetic field transverse to the axis of rotation. The spinning Hall probe device has been realized. Alignment of the spinning axis for a minimum (zero) value of the signal allows us to find the direction of the magnetic field. The device does not require calibration and is free of any drift problems. The measurement of the rotation axis direction was accomplished by means of a laser and a flat mirror attached to the rotor. The constructed prototype achieved an accuracy for the magnetic field direction in the experiment with the polarized He-3 target on the level of one milli radian.

   nucl-exphysics.ins-detPoS(2024)·0 citations
4. 04*

   Final Search for Short-Baseline Neutrino Oscillations with the PROSPECT-I Detector at HFIR

   M. Andriamirado🇺🇸 · B. Balantekin🇺🇸 · C. D. Bass🇺🇸 · O. Benevides Rodrigues🇺🇸 · E. P. Bernard🇺🇸 · N. S. Bowden🇺🇸 · C. D. Bryan🇺🇸 · R. Carr🇺🇸 · T. Classen🇺🇸 · A. J. Conant🇺🇸 · G. Deichert🇺🇸 · M. J. Dolinski🇺🇸 and 35 other authors

   The PROSPECT experiment is designed to perform precise searches for antineutrino disappearance at short distances (7 - 9~m) from compact nuclear reactor cores. This Letter reports results from a new neutrino oscillation analysis performed using the complete data sample from the PROSPECT-I detector operated at the High Flux Isotope Reactor in 2018. The analysis uses a multi-period selection of inverse beta decay neutrino interactions with reduced backgrounds and enhanced statistical power to set limits on electron-flavor disappearance caused by mixing with sterile neutrinos with 0.2 - 20 eV${}^2$ mass splittings. Inverse beta decay positron energy spectra from six different reactor-detector distance ranges are found to be statistically consistent with one another, as would be expected in the absence of sterile neutrino oscillations. The data excludes at 95% confidence level the existence of sterile neutrinos in regions above 3~eV${}^2$ previously unexplored by terrestrial experiments, including all space below 10~eV${}^2$ suggested by the recently strengthened Gallium Anomaly. The best-fit point of the Neutrino-4 reactor experiment's claimed observation of short-baseline oscillation is ruled out at more than five standard deviations.

   ↳ hep-exnucl-exPRL(2025)·33 citations
5. 05*

   Quarkonium fragmentation in a variable-flavor number scheme: Towards NRFF1.0

   Francesco Giovanni Celiberto🇪🇸

   We report progress on the determination and study of quarkonium production within the fragmentation approximation. Our analyses address the moderate and large transverse-momentum regime, where the collinear fragmentation of a single parton is expected to dominate over the short-distance production, directly from the hard scattering, of the constituent $(Q\bar{Q})$ system. Parton fragmentation channels to pseudoscalar and vector quarkonia are built on the basis of non-Relativistic QCD next-to-leading computations, which we use to model initial-scale fragmentation inputs. Thus, a preliminary family of Variable-Flavor Number-Scheme (VFNS) fragmentation functions, named NRFF1.0, are constructed through standard DGLAP evolution. Statistical uncertainties are obtained from a Monte Carlo, replica-like approach embodying missing higher-order uncertainties.

   ↳ hep-phhep-exnucl-exnucl-thPoS(2025)·19 citations
6. 06*

   $B_c^{\pm }$-${}^{12}$C states and detailed study of momentum space method for ${\rm Y}$- and ${\eta }_b$-nucleus bound states

   G. N. Zeminiani🇧🇷 · J. J. Cobos-Martínez🇲🇽 · K. Tsushima🇧🇷

   We perform a detailed study of the ${\rm Y}$-, ${\eta }_b$-, and $B_c$-nucleus systems in momentum space to calculate the bound-state energies and the corresponding coordinate-space radial wave functions. The attractive strong potentials for the meson-nucleus systems are calculated from the Lorentz scalar mass modifications of these mesons in nuclear matter in the local density approximation in the nucleus. The downward shift of the meson masses may be regarded as a signature of partial restoration of chiral symmetry in a nuclear medium applied in the present study in an empirical sense, because the origin of the negative mass shift in this study is not directly related to the chiral symmetry mechanism. Furthermore, as an initial and realistic study, the $B_c^{\pm }$-${}^{12}$C bound states are studied for the first time, with the effects of self-consistently calculated Coulomb potentials in ${}^{12}$C (when the $B_c^{\pm }$ mesons are absent).

   ↳ nucl-thhep-exhep-phnucl-exPRC(2025)·5 citations
7. 07*

   Investigating the excitation function of HBT radii for Lévy-stable sources

   Mate Csanad🇭🇺 · Daniel Kincses🇭🇺

   Contemporary heavy-ion physics research aims to explore the phase diagram of strongly interacting matter and search for signs of the possible critical endpoint on the QCD phase diagram. Femtoscopy is among the important tools used for this endeavor; there have been indications that combinations of femtoscopic radii parameters (referred to as HBT radii for identical boson pairs) can be related to the system's emission duration. An apparent non-monotonic behavior in their excitation function thus might signal the location of the critical point. In this paper, we show that conclusions drawn from the results obtained with a Gaussian approximation for the pion source shape might be altered if one utilizes a more general Lévy-stable source description. We find that the characteristic size of the pion source function is strongly connected to the shape of the source and its possible power-law behavior. Taking this into account properly changes the observed behavior of the excitation function.

   ↳ nucl-thhep-phnucl-exJ.Phys.G(2025)·8 citations
8. 08*

   Measurement of $J/\psi$ and $\psi \left(2S\right)$ production in $p+p$ and $p+d$ interactions at 120 GeV

   C. H. Leung🇺🇸 · K. Nagai🇯🇵 · K. Nakano🇯🇵 · D. Nawarathne🇺🇸 · J. Dove🇺🇸 · S. Prasad🇺🇸 · N. Wuerfel🇺🇸 · C. A. Aidala🇺🇸 · J. Arrington🇺🇸 · C. Ayuso🇺🇸 · C. L. Barker🇺🇸 · C. N. Brown🇺🇸 and 49 other authors

   We report the $p+p$ and $p+d$ differential cross sections measured in the SeaQuest experiment for $J/\psi$ and $\psi \left(2S\right)$ production at 120 GeV beam energy covering the forward $x$-Feynman ($x_F$) range of $0.5<x_F<0.9$. The measured cross sections are in good agreement with theoretical calculations based on the nonrelativistic QCD (NRQCD) using the long-distance matrix elements deduced from a recent global analysis of proton- and pion-induced charmonium production data. The ${\sigma }_{\psi \left(2S\right)}/{\sigma }_{J/\psi }$ cross section ratios are found to increase as $x_F$ increases, indicating that the $q\bar{q}$ annihilation process has larger contributions in the $\psi \left(2S\right)$ production than the $J/\psi$ production. The ${\sigma }_{pd}/2{\sigma }_{pp}$ cross section ratios are observed to be significantly different for the Drell-Yan process and $J/\psi$ production, reflecting their different production mechanisms. We find that the ${\sigma }_{pd}/2{\sigma }_{pp}$ ratios for $J/\psi$ production at the forward $x_F$ region are sensitive to the $\bar{d}/\bar{u}$ flavor asymmetry of the proton sea, analogous to the Drell-Yan process. The transverse momentum ($p_T$) distributions for $J/\psi$ and $\psi \left(2S\right)$ production are also presented and compared with data collected at higher center-of-mass energies.

   ↳ hep-exnucl-exPLB(2024)·4 citations
9. 09*

   Four-dimensional QCD equation of state with multiple chemical potentials

   Akihiko Monnai🇯🇵 · Grégoire Pihan🇺🇸 · Björn Schenke🇺🇸 · Chun Shen🇺🇸

   We construct a four-dimensional version of the equation of state (EoS) model NEOS, NEOS-4D, as a function of the temperature and chemical potentials of baryon, electric charge, and strangeness for the hot and dense QCD matter created in relativistic nuclear collisions. This EoS enables multiple conserved charge current evolution in a relativistic fluid. Input from Lattice QCD simulations and a hadron resonance gas model is considered for constructing the equation of state. We investigate its applicability to the relativistic hydrodynamic description of nuclear collisions and present a method for efficient numerical implementation.

   ↳ nucl-thhep-phnucl-exPRC(2024)·26 citations
10. 10*

    Helicity Evolution at Small $x$: Quark to Gluon and Gluon to Quark Transition Operators

    Jeremy Borden🇺🇸 · Yuri V. Kovchegov🇺🇸 · Ming Li🇺🇸

    We include the quark to gluon and gluon to quark shock-wave transition operators into the small Bjorken-$x$ evolution equations for helicity in the flavor-singlet channel derived earlier. While such transitions do not affect the large-$N_c$ version of the evolution equations for helicity, the large-$N_c\&N_f$ equations are affected. ($N_c$ and $N_f$ are the numbers of quark colors and flavors, respectively.) We derive the corresponding corrected large-$N_c\&N_f$ equations for the polarized dipole amplitudes contributing to the flavor-singlet quark and gluon helicity distributions in the double-logarithmic approximation (DLA), resumming powers of ${\alpha }_s{\ln }^2(1/x)$ with ${\alpha }_s$ the strong coupling constant. We solve these equations iteratively and extract the polarized splitting functions up to four loops. We show that our splitting functions agree with the fixed-order perturbative calculations up to and including the existing three-loops results. Similar to the large-$N_c$ helicity evolution in the shock-wave approach, our large-$N_c\&N_f$ small-$x$ splitting functions agree with those obtained in the infrared evolution equations framework up to three loops, but appear to slightly disagree at four loops.

    ↳ hep-phnucl-exnucl-thJHEP(2024)·28 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.