Wed·Mar 22, 2023Wednesday·March 22, 2023

1. 01*

   Cyclotron Radiation Emission Spectroscopy of Electrons from Tritium Beta Decay and ${}^{83\mathrm{m}}$Kr Internal Conversion

   Project 8 Collaboration: A. Ashtari Esfahani🇺🇸 · S. Böser🇩🇪 · N. Buzinsky🇺🇸 · M. C. Carmona-Benitez🇺🇸 · C. Claessens🇺🇸 · L. de Viveiros🇺🇸 · P. J. Doe🇺🇸 · M. Fertl🇩🇪 · J. A. Formaggio🇺🇸 · J. K. Gaison🇺🇸 · L. Gladstone🇺🇸 · M. Guigue🇫🇷 and 44 other authors

   Project 8 has developed a novel technique, Cyclotron Radiation Emission Spectroscopy (CRES), for direct neutrino mass measurements. A CRES-based experiment on the beta spectrum of tritium has been carried out in a small-volume apparatus. We provide a detailed account of the experiment, focusing on systematic effects and analysis techniques. In a Bayesian (frequentist) analysis, we measure the tritium endpoint as $18553_{-19}^{+18}$ ($18548_{-19}^{+19}$) eV and set upper limits of 155 (152) eV (90% C.L.) on the neutrino mass. No background events are observed beyond the endpoint in 82 days of running. We also demonstrate an energy resolution of $1.66\pm 0.19$ eV in a resolution-optimized magnetic trap configuration by measuring ${}^{83\mathrm{m}}$Kr 17.8-keV internal-conversion electrons. These measurements establish CRES as a low-background, high-resolution technique with the potential to advance neutrino mass sensitivity.

   nucl-exhep-exPRC(2024)·27 citations
2. 02*

   Structure of Nucleons and Their Interaction in the Concept of Nonperturbative QCD as a Pressing Issue of 21st-Century Physics

   Vladimir I. Komarov🇷🇺

   The problem of the structure of nucleons and their interaction in the concept of nonperturbative QCD is discussed as an approach to studying the transformation of current quarks into constituent ones and the search for the mechanism of such a transformation, creating the bulk of the nucleon mass. Attention is drawn to the possibilities offered by studying central nucleon-nucleon collisions in this aspect.

   ↳ hep-phnucl-exnucl-thPhys.Part.Nucl.Lett.(2022)·1 citation
3. 03*

   Shedding light on shadow generalized parton distributions

   Eric Moffat🇺🇸 · Adam Freese🇺🇸 · Ian Cloët🇺🇸 · Thomas Donohoe🇺🇸 · Leonard Gamberg🇺🇸 · Wally Melnitchouk🇺🇸 · Andreas Metz🇺🇸 · Alexei Prokudin🇺🇸 · Nobuo Sato🇺🇸

   The feasibility of extracting generalized parton distributions (GPDs) from deeply-virtual Compton scattering (DVCS) data has recently been questioned because of the existence of an infinite set of so-called ''shadow GPDs'' (SGPDs). These SGPDs depend on the process and manifest as multiple solutions (at a fixed scale $Q^2$) to the inverse problem that needs to be solved to infer GPDs from DVCS data. SGPDs therefore pose a significant challenge for extracting GPDs from DVCS data. With this motivation we study the extent to which QCD evolution can provide constraints on SGPDs. This is possible because the known classes of SGPDs begin to contribute to observables after evolution, and can then be constrained (at the input scale $Q_0^2$) by data that has a finite $Q^2$ range. The impact that SGPDs could have on determining the total angular momentum, pressure and sheer force distributions, and tomography is also discussed. Our key finding is that scale evolution, coupled with data over a wide range of skewness $\xi$ and $Q^2$, can constrain the class of SGPDs that we studied and potentially make possible the extraction of GPDs from DVCS data over a limited range in the GPD variables.

   ↳ hep-phnucl-exnucl-thPRD(2023)·51 citations
4. 04*

   Photoproduction of $J/\psi$ with neutron tagging in ultra-peripheral collisions of nuclei at RHIC and the LHC

   E. Kryshen (St. Petersburg, INP)🇷🇺 · M. Strikman (Penn State U.)🇺🇸 · M. Zhalov (St. Petersburg, INP)🇷🇺

   We present predictions for the cross sections of the coherent and incoherent $J/\psi$ photoproduction in ultra-peripheral collisions at RHIC and at the LHC calculated for different classes of events depending on the presence of neutrons emitted by colliding nuclei. Since strong nucleus-nucleus interactions in UPCs are suppressed, it is usually assumed that neutrons at forward rapidities originate mainly from the electromagnetic dissociation of colliding nuclei caused by additional photon exchanges. This is a reasonable assumption for the coherent photoproduction where the state of the target nucleus remains intact. We consider additional sources of neutrons in the incoherent quasielastic and nucleon dissociative $J/\psi$ photoproduction and show that these processes significantly change probabilities of neutron emission compared to calculations when only neutrons from electromagnetic dissociation of nuclei are considered. Such studies should allow one to explore the dynamics of nuclear shadowing in the incoherent $J/\psi$ photoproduction down to $x\sim 10^{-5}$.

   ↳ hep-phhep-exnucl-exPRC(2023)·14 citations
5. 05*

   A Comparative Analysis between Unbiased Exponential Resummation and Taylor Expansion in Finite-Density QCD with a new phasefactor for Isospin

   Sabarnya Mitra🇮🇳

   The recently introduced unbiased exponential resummation at finite chemical potential has become an important approach which promises to capture reliably the behaviour of higher order conserved charge cumulants appearing otherwise in the finite-density QCD Taylor series of thermodynamic observables. In this paper, we present a thorough analysis of the estimates of charge cumulants upto eighth order and have compared them using Taylor expansion method and unbiased exponential resummation approach for baryon and isospin chemical potentials. We also subsequently compare the different estimates of the radius of convergence obtained using these two methods and check if the zeros of phasefactor for baryochemical potential can indicate something about these estimated values. We propose a new method of finding a non-trivial phasefactor for isospin chemical potential and we attempt explaining the different estimates of radius of convergence from the zeroes of this newly constructed gauge-ensemble average phasefactor for isospin chemical potential. Lastly, we also illustrate kurtosis plots describing the behaviour of overlap problem in isospin chemical potential and check if it maintains consistency with the appearance of zeros of the newly proposed phasefactor.

   ↳ hep-lathep-phnucl-exnucl-th1 citation
6. 06*

   Voltage scanning and technical upgrades at the Collinear Resonance Ionization Spectroscopy experiment

   Michail Athanasakis-Kaklamanakis🇨🇭 · Jordan R. Reilly🇬🇧 · Agota Koszorus🇨🇭 · Shane G. Wilkins🇺🇸 · Louis Lalanne🇧🇪 · Sarina Geldhof🇧🇪 · Miranda Nichols🇸🇪 · Quanjun Wang🇨🇳 · Bram van den Borne🇧🇪 · David Chorlton🇬🇧 · Thomas E. Cocolios🇧🇪 · Kieran T. Flanagan🇬🇧 and 7 other authors

   To optimize the performance of the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at CERN-ISOLDE, technical upgrades are continuously introduced, aiming to enhance its sensitivity, precision, stability, and efficiency. Recently, a voltage-scanning setup was developed and commissioned at CRIS, which improved the scanning speed by a factor of three as compared to the current laser-frequency scanning approach. This leads to faster measurements of the hyperfine structure for systems with high yields (more than a few thousand ions per second). Additionally, several beamline sections have been redesigned and manufactured, including a new field-ionization unit, a sharper electrostatic bend, and improved ion optics. The beamline upgrades are expected to yield an improvement of at least a factor of 5 in the signal-to-noise ratio by suppressing the non-resonant laser ions and providing time-of-flight separation between the resonant ions and the collisional background. Overall, the presented developments will further improve the selectivity, sensitivity, and efficiency of the CRIS technique.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.B(2023)·3 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.