Fri·Mar 10, 2023Friday·March 10, 2023

1. 01*

   Multi-scale Imaging of Nuclear Deformation at the Electron Ion Collider

   Heikki Mäntysaari🇫🇮 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇺🇸

   We show within the Color Glass Condensate framework that exclusive vector meson production at high energy is sensitive to the geometric deformation of the target nucleus at multiple length scales. Studying $e+$U collisions and varying the deformation of the uranium target, we demonstrate that larger deformations result in enhanced incoherent vector meson production cross sections. Further, different multipole deformation parameters affect different regions of transverse momentum transfer. Employing JIMWLK evolution to study the Bjorken-$x$ dependence of our results, we find that the ratio of incoherent to coherent cross sections decreases with decreasing $x$, largely independently of the quadrupole deformation of the target. Comparing results for the same process using ${}^{20}\mathrm{Ne}$ targets with ${}^{16}\mathrm{O}$ targets, we find that differences in deformation are clearly visible in the incoherent cross section. These findings show that certain observables at the Electron-Ion Collider are very sensitive to nuclear structure. Consequently, deformations need to be taken into account when interpreting experimental results. More importantly, this also means that $|t|$-differential diffractive vector meson production could become a powerful tool, enabling the most direct measurements of nuclear structure at different length scales, ranging from nuclear deformation at low $|t|$ to nucleon- and subnucleon-size scales at higher $|t|$.

   ↳ nucl-thhep-phnucl-exPRL(2023)·43 citations
2. 02*

   Strong Interaction Dynamics and Fermi $\beta$ decay in the nucleon and the nucleus

   Gerald A. Miller🇺🇸

   Nuclear super-allowed $\beta$ decay has been used to obtain tight limits on the value of the CKM matrix element $V_{ud}$ that is important for unitarity tests, and therefore important for tests of the standard model. Current requirements on precision are so intense that effects formerly thought too small to matter are now relevant. This article is a brief review of personal efforts to include the effects of strong interactions on Fermi $\beta$ decay. First I examine the role of isospin violation in the decay of the neutron. The size of the necessary correction depends upon detailed strong-interaction dynamics. The isospin violating parts of the nucleon wave function, important at the low energy of $\beta$ decay, can be constrained by data taken at much higher energies, via measurements, for example, of $ed\to e^{\prime }{\pi }^{\pm }+\mathrm{X}$ reactions at Jefferson Laboratory. The next focus is on the role of nuclear short-ranged correlations, which affect the value of the correction needed to account for isospin violation in extracting the value of $V_{ud}$. The net result is that effects previously considered as irrelevant have become relevant for both neutron and nuclear $\beta$ decay.

   ↳ nucl-thnucl-exUniverse(2023)·2 citations
3. 03*

   The resolution to the problem of consistent large transverse momentum in TMDs

   J. O. Gonzalez-Hernandez🇮🇹 · T. Rainaldi🇺🇸 · T. C. Rogers🇺🇸

   Parametrizing TMD parton densities and fragmentation functions in ways that consistently match their large transverse momentum behavior in standard collinear factorization has remained notoriously difficult. We show how the problem is solved in a recently introduced set of steps for combining perturbative and nonperturbative transverse momentum in TMD factorization. Called a ``bottom-up'' approach in a previous article, here we call it a ``hadron structure oriented'' (HSO) approach to emphasize its focus on preserving a connection to the TMD parton model interpretation. We show that the associated consistency constraints improve considerably the agreement between parametrizations of TMD functions and their large-$k_T$ behavior, as calculated in collinear factorization. The procedure discussed herein will be important for guiding future extractions of TMD parton densities and fragmentation functions and for testing TMD factorization and universality. We illustrate the procedure with an application to semi-inclusive deep inelastic scattering (SIDIS) structure functions at an input scale $Q_0$, and we show that there is improved consistency between different methods of calculating at moderate transverse momentum. We end with a discussion of plans for future phenomenological applications.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2023)·19 citations
4. 04*

   The effects of a passive Bi-Polar Grid (BPG) on Ion Back-Flow (IBF) and Resolution

   V. Zakharov🇺🇸 · E. Shulga🇺🇸 · P. Garg · T. Hemmick🇺🇸 · A. Milov🇮🇱

   Time Projection Chambers (TPC)s are excellent tracking detectors for high multiplicity events and can intrinsically be high-rate, but are limited by the ions created in their avalanche stage. GEMs and Micromegas can reduce IBF through their geometry and E-field ratios, but these can lead to gain fluctuations and still leave IBF as the dominant source of space charge. An active BPG can block all IBF ions, but their slow drift speed creates too much dead time. A passive BPG will overcome this limitation by using an external B-field to allow the electrons to pass through while still blocking all ions. Since the grid changes the electron's trajectory, a loss of resolution will occur. The trajectory is shifted symmetrically along the wires so the wire alignment with respect to the detection pads is a specific question not studied before. We present completed IBF analysis from data collected at Weizmann Institute of Science (WIS), along with an intro to our test on wire resolution.

   ↳ physics.ins-detnucl-exJINST(2023)·0 citations
5. 05*

   Search for Majorana neutrinos

   Itaru Shimizu🇯🇵

   Whether there exist elementary particles having Majorana nature is one the fundamental open question that has persisted since the 1930s. The only practical experiments to test the Majorana nature of neutrinos is the search for neutrinoless double-beta decay, which has been a major challenge for nuclear and particle physicists. In the 2000's, a number of experiments using advanced technologies have been planned, and some of which have already achieved significant improvements in the search sensitivity. In this article, the current status of the neutrinoless double-beta decay searches are summarized, reviewing the progress of KamLAND-Zen, which recorded the world best sensitivity in the effective Majorana neutrino mass limit.

   ↳ hep-exnucl-exPTEP(2024)·6 citations
6. 06*

   Inclusive and diffractive dijet photoproduction at the Electron-Ion Collider in NLO QCD

   V. Guzey (Jyvaskyla U. and Helsinki U.)🇫🇮 · M. Klasen (Munster U., ITP)🇩🇪

   In the framework of collinear factorization and next-to-leading order (NLO) perturbative QCD, we make predictions for inclusive and diffractive dijet photoproduction in electron-proton and electron-nucleus scattering in the EIC kinematics. We establish kinematic ranges in the ${\bar{p}}_T$, $\bar{\eta }$, $x_A^{\mathrm{obs}}$ and $x_{\gamma }^{\mathrm{obs}}$ variables, quantify sensitivity to small-$x$ nuclear PDFs, and analyze various scenarios of factorization breaking in the case of diffractive scattering.

   ↳ hep-phhep-exnucl-exActa Phys.Polon.Supp.(2023)·4 citations
7. 07*

   P-even and -odd asymmetries on ${}^{117}$Sn at the vicinity of the p-resonance E${}_{\mathrm{p}}$=1.33 eV

   L. E. Charón-García · J. Curole · L. Barrón-Palos🇲🇽 · V. Gudkov🇺🇸 · W. M. Snow🇺🇸

   A self consistent description of angular correlations in neutron induced reactions is required for quantitative analysis of parity violating (PV) and time reversal invariance violating (TRIV) effects in neutron nucleus scattering. The 1.33 eV p-wave compound resonance in ${}^{117}$Sn is one of the few p-wave resonances where enough measurements have been performed to allow a nontrivial test of the internal consistency of the theory. We present the results of a global analysis of the several different asymmetries and angular distribution measurements in ($n,\gamma$) reactions on the 1.33 eV p-wave resonance in ${}^{117}$Sn conducted over the last few decades. We show that the compound resonance mixing theory can give an internally consistent description of all observations made in this system to date within the experimental measurement errors. We also confirm the conclusions of previous analyses that a subthreshold resonance in ${}^{117}$Sn dominates correlations related to s-p mixing, and discuss the implications of these results for future searches for TRIV in this system.

   ↳ nucl-thnucl-ex0 citations
8. 08*

   Performance of a liquid nitrogen cryostat setup for the study of nuclear recoils in undoped CsI crystals

   K. Ding🇺🇸 · J. Liu🇺🇸 · Y. Yang🇹🇼 · K. Scholberg🇺🇸 · D.M. Markoff🇺🇸

   There is a global trend to increase the light yield of CsI scintillators used in neutrino and dark matter detection by operating undoped crystals at cryogenic temperatures. However, high light yield alone is not sufficient to guarantee a low-energy threshold. The response of undoped crystals to nuclear recoils at cryogenic temperatures is equally important. A liquid nitrogen-based cryostat was developed to measure the nuclear quenching factor of a small undoped CsI crystal using monoenergetic neutron beams at the Triangle Universities Nuclear Laboratory (TUNL). To avoid neutron scattering in high-$Z$ materials, these materials were intentionally reduced around the crystal. The structure and performance of the cryostat are described in detail. Using this cryostat, a light yield of $33.4\pm 1.7$ photoelectrons per keV electron-equivalent (PE/keV${}_{\text{ee}}$) was observed at 5.9 keV${}_{\text{ee}}$, enabling the measurement of nuclear quenching factors at very low energies. The results of the quenching factor measurement will be reported in a subsequent paper. Non-negligible negative overshoot was observed in the tails of the observed light pulses. The origin of this issue and the correction procedure are described in detail. This information may be useful for others who encounter similar technical challenges.

   ↳ physics.ins-dethep-exnucl-exNucl.Instrum.Meth.A(2024)·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.