Tue·Oct 20, 2020Tuesday·October 20, 2020

1. 01*

   Search for double beta decay of ${}^{106}$Cd with an enriched ${}^{106}$CdWO${}_4$ crystal scintillator in coincidence with CdWO${}_4$ scintillation counters

   P. Belli🇮🇹 · R. Bernabei🇮🇹 · V.B. Brudanin🇷🇺 · F. Cappella🇮🇹 · V. Caracciolo🇮🇹 · R. Cerulli🇮🇹 · F.A. Danevich🇺🇦 · A. Incicchitti🇮🇹 · D.V. Kasperovych🇺🇦 · V.R. Klavdiienko🇺🇦 · V.V. Kobychev🇺🇦 · V. Merlo🇮🇹 and 3 other authors

   Studies on double beta decay processes in ${}^{106}$Cd were performed by using a cadmium tungstate scintillator enriched in ${}^{106}$Cd at 66% (${}^{106}$CdWO${}_4$) with two CdWO${}_4$ scintillation counters (with natural Cd composition). No effect was observed in the data accumulated over 26033 h. New improved half-life limits were set on the different channels and modes of the ${}^{106}$Cd double beta decay at level of $\lim T_{1/2}\sim 10^{20}-10^{22}$ yr. The limit for the two neutrino electron capture with positron emission in ${}^{106}$Cd to the ground state of ${}^{106}$Pd, $T_{1/2}^{2\nu \mathrm{EC}{\beta }^{+}}\ge 2.1\times 10^{21}$ yr, was set by the analysis of the ${}^{106}$CdWO${}_4$ data in coincidence with the energy release 511 keV in both CdWO${}_4$ counters. The sensitivity approaches the theoretical predictions for the decay half-life that are in the range $T_{1/2}\sim 10^{21}-10^{22}$ yr. The resonant neutrinoless double-electron capture to the 2718 keV excited state of ${}^{106}$Pd is restricted at the level of $T_{1/2}^{0\nu 2K}\ge 2.9\times 10^{21}$ yr

   nucl-exUniverse(2020)·19 citations
2. 02*

   Investigating Heavy-flavor vs Light-flavor Puzzle with Event Topology and Multiplicity in Proton+Proton Collisions at $\sqrt{s}$ = 13 TeV using PYTHIA8

   Suman Deb🇮🇳 · Raghunath Sahoo🇮🇳 · Dhananjaya Thakur🇨🇳 · Sushanta Tripathy🇲🇽 · Arvind Khuntia🇵🇱

   Heavy-flavored hadrons are unique probes to study the properties of hot and dense QCD medium produced in ultra-relativistic heavy-ion collisions at RHIC and the LHC. Transverse spherocity is one of the event-topology variables used to separate jetty and isotropic events from the pool of event samples. This study aims to understand the production dynamics of heavy-flavors through the transverse momentum spectra, double differential yield and mean transverse momentum of J/$\psi$, ${\mathrm{D}}^0$ and ${\Lambda }_c^{+}$ as a function of charged-particle multiplicity and transverse spherocity. Further to investigate the possibility of hardonization of the charm quarks, transverse spherocity dependence ratios like ${\Lambda }_c^{+}$/${\mathrm{D}}^0$ and ${\Lambda }^0$/$K^{-}$ are studied. For the current analysis, the events are generated by using 4C tuned PYTHIA8 for pp at $\sqrt{s}$ = 13 TeV, which is quite successful in explaining the heavy-flavor particle production at the LHC energies.

   nucl-exhep-exhep-phhep-th+1J.Phys.G(2021)·8 citations
3. 03*

   Advanced extraction of the deuteron charge radius from electron-deuteron scattering data

   Jingyi Zhou🇺🇸 · Vladimir Khachatryan🇺🇸 · Haiyan Gao🇺🇸 · Douglas W. Higinbotham🇺🇸 · Asia Parker🇺🇸 · Xinzhan Bai🇺🇸 · Dipangkar Dutta🇺🇸 · Ashot Gasparian🇺🇸 · Kondo Gnanvo🇺🇸 · Mahbub Khandaker🇺🇸 · Nilanga Liyanage🇺🇸 · Eugene Pasyuk🇺🇸 · Chao Peng🇺🇸 · Weizhi Xiong🇺🇸

   To extract the charge radius of the proton, $r_p$, from the electron scattering data, the PRad collaboration at Jefferson Lab has developed a rigorous framework for finding the best functional forms - the fitters - for a robust extraction of $r_p$ from a wide variety of sample functions for the range and uncertainties of the PRad data. In this paper we utilize and further develop this framework. Herein we discuss methods for searching for the best fitter candidates as well as a procedure for testing the robustness of extraction of the deuteron charge radius, $r_d$, from parametrizations based on elastic electron-deuteron scattering data. The ansatz proposed in this paper for the robust extraction of $r_d$, for the proposed low-$Q^2$ DRad experiment at Jefferson Lab, can be further improved once there are more data.

   nucl-exhep-phnucl-thPRC(2021)·10 citations
4. 04*

   Limits on the Existence of sub-MeV Sterile Neutrinos from the Decay of ${}^7$Be in Superconducting Quantum Sensors

   S. Friedrich🇺🇸 · G.B. Kim🇺🇸 · C. Bray🇺🇸 · R. Cantor🇺🇸 · J. Dilling🇨🇦 · S. Fretwell🇺🇸 · J.A. Hall🇺🇸 · A. Lennarz🇨🇦 · V. Lordi🇺🇸 · P. Machule🇨🇦 · D. McKeen🇨🇦 · X. Mougeot🇫🇷 and 5 other authors

   Sterile neutrinos are natural extensions to the standard model of particle physics and provide a possible portal to the dark sector. We report a new search for the existence of sub-MeV sterile neutrinos using the decay-momentum reconstruction technique in the decay of ${}^7$Be. The experiment measures the total energy of the ${}^7$Li daughter atom from the electron capture decay of ${}^7$Be implanted into sensitive superconducting tunnel junction (STJ) quantum sensors. This first experiment presents data from a single STJ operated at a low count rate for a net total of 28 days, and provides exclusion limits on sterile neutrinos in the mass range from 100 to 850 keV that improve upon previous work by up to an order of magnitude.

   nucl-exhep-exquant-phPRL(2021)·75 citations
5. 05*

   Resonant states in ${}^7$H. I. Experimental studies of the ${}^2$H(${}^8$He,${}^3$He) reaction

   I.A. Muzalevskii🇷🇺 · A.A. Bezbakh🇷🇺 · E.Yu. Nikolskii · V. Chudoba🇷🇺 · S.A. Krupko🇷🇺 · S.G. Belogurov🇷🇺 · D. Biare🇷🇺 · A.S. Fomichev🇷🇺 · E.M. Gazeeva🇷🇺 · A.V. Gorshkov🇺🇸 · L.V. Grigorenko🇷🇺 · G. Kaminski and 21 other authors

   The extremely neutron-rich system ${}^7$H was studied in the direct ${}^2$H(${}^8$He,${}^3$He)${}^7$H transfer reaction with a 26 AMeV secondary ${}^8$He beam [Bezbakh et al., Phys. Rev. Lett. 124 (2020) 022502]. The missing mass spectrum and center-of-mass (c.m.) angular distributions of ${}^7$H, as well as the momentum distribution of the ${}^3$H fragment in the ${}^7$H frame, were constructed. In addition to the investigation reported in Ref. [Bezbakh et al., Phys. Rev. Lett. 124 (2020) 022502], we carried out another experiment with the same beam but a modified setup, which was cross-checked by the study of the ${}^2$H(${}^{10}$Be,${}^3$He${)}^9$Li reaction. A solid experimental evidence is provided that two resonant states of ${}^7$H are located in its spectrum at 2.2(5) and 5.5(3) MeV relative to the ${}^3$H+4$n$ decay threshold. Also, there are indications that the resonant states at 7.5(3) and 11.0(3) MeV are present in the measured ${}^7$H spectrum. Based on the energy and angular distributions, obtained for the studied ${}^2$H(${}^8$He,${}^3$He)${}^7$H reaction, the weakly populated 2.2(5) MeV peak is ascribed to the ${}^7$H ground state. It is highly plausible that the firmly ascertained 5.5(3) MeV state is the $5/2^{+}$ member of the ${}^7$H excitation $5/2^{+}$-$3/2^{+}$ doublet, built on the $2^{+}$ configuration of valence neutrons. The supposed 7.5 MeV state can be another member of this doublet, which could not be resolved in Ref. [Bezbakh et al., Phys. Rev. Lett. 124 (2020) 022502]. Consequently, the two doublet members appeared in the spectrum of ${}^7$H in [Bezbakh et al., Phys. Rev. Lett. 124 (2020) 022502] as a single broad 6.5 MeV peak.

   nucl-exPRC(2021)·16 citations
6. 06*

   Ab initio benchmarks of neutrinoless double beta decay in light nuclei with a chiral Hamiltonian

   J. M. Yao🇺🇸 · A. Belley🇨🇦 · R. Wirth🇺🇸 · T. Miyagi🇨🇦 · C. G. Payne🇨🇦 · S. R. Stroberg🇺🇸 · H. Hergert🇺🇸 · J. D. Holt🇨🇦

   We report ab initio benchmark calculations of nuclear matrix elements (NMEs) for neutrinoless double-beta ($0\nu \beta \beta$) decays in light nuclei with mass number ranging from $A=6$ to $A=22$. We use the transition operator derived from light-Majorana neutrino exchange and evaluate the NME with three different methods: two variants of in-medium similarity renormalization group (IMSRG) and importance-truncated no-core shell model (IT-NCSM). The same two-plus-three-nucleon interaction from chiral effective field theory is employed, and both isospin-conserving ($\Delta T=0$) and isospin-changing ($\Delta T=2$) transitions are studied. We compare our resulting ground-state energies and NMEs to those of recent ab initio no-core shell model and coupled-cluster calculations, also with the same inputs. We show that the NMEs of $\Delta T=0$ transitions are in good agreement among all calculations, at the level of 10%. For $\Delta T=2$, relative deviations are more significant in some nuclei. The comparison with the exact IT-NCSM result allows us to analyze these cases in detail, and indicates the next steps towards improving the IMSRG-based approaches. The present study clearly demonstrates the power of consistent cross-checks that are made possible by ab initio methodology. This capability is crucial for providing meaningful many-body uncertainties in the NMEs for the $0\nu \beta \beta$ decays in heavier candidate nuclei, where quasi-exact benchmarks are not available.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2021)·44 citations
7. 07*

   Searches for new sources of CP violation using molecules as quantum sensors

   N. R. Hutzler🇺🇸 · A. Borschevsky🇳🇱 · D. Budker🇩🇪 · D. DeMille🇺🇸 · V. V. Flambaum🇦🇺 · G. Gabrielse🇺🇸 · R. F. Garcia Ruiz🇺🇸 · A. M. Jayich🇺🇸 · L. A. Orozco🇺🇸 · M. Ramsey-Musolf🇺🇸 · M. Reece🇺🇸 · M. S. Safronova🇺🇸 and 3 other authors

   We discuss how molecule-based searches offer complementary probes to study the violation of fundamental symmetries. These experiments have the potential to probe not only the electron EDM, but also hadronic CPV phenomena. Future experimental developments will offer generic sensitivity to probe flavor neutral sources of both leptonic and hadronic CPV at scales of $\ge$ 100 TeV, and flavor changing CPV at scales of $\ge$ 1000 TeV.

   ↳ hep-phhep-exnucl-exSnowmass LOI 2020·18 citations
8. 08*

   Future Physics Perspectives on the Equation of State from Heavy Ion Collisions to Neutron Stars

   Veronica Dexheimer🇺🇸 · Jorge Noronha🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Claudia Ratti🇺🇸 · Nicolás Yunes🇺🇸

   With the computational power and algorithmic improvements available today, the ongoing STAR/RHIC and HADES/GSI experiments, the future FAIR and NICA facilities becoming operational, and the new precise measurements from NICER and LIGO/VIRGO, the high-energy nuclear physics and astrophysics communities are in the unique position to set very stringent constraints on the equation of state of strongly interacting matter. We review the state-of-the-art of different approaches used in the description of hot and ultradense baryonic matter in and out of equilibrium, and discuss the regions in the phase diagram where heavy-ion collisions and neutron star mergers can overlap. Future perspectives are discussed to help define a comprehensive, multi-disciplinary strategy to map out the phase diagram of strongly interacting matter from heavy ion collisions to neutron stars.

   ↳ nucl-thastro-ph.HEgr-qchep-ph+1J.Phys.G(2021)·79 citations
9. 09*

   Vorticity and Spin Polarization in Heavy Ion Collisions: Transport Models

   Xu-Guang Huang🇨🇳 · Jinfeng Liao🇺🇸 · Qun Wang🇨🇳 · Xiao-Liang Xia🇨🇳

   Heavy ion collisions generate strong fluid vorticty in the produced hot quark-gluon matter which could in turn induce measurable spin polarization of hadrons. We review recent progress on the vorticity formation and spin polarization in heavy ion collisions with transport models. We present an introduction to the fluid vorticity in non-relativistic and relativistic hydrodynamics and address various properties of the vorticity formed in heavy ion collisions. We discuss the spin polarization in a vortical fluid using the Wigner function formalism in which we derive the freeze-out formula for the spin polarization. Finally we give a brief overview of recent theoretical results for both the global and local spin polarization of $\Lambda$ and $\bar{\Lambda }$ hyperons.

   ↳ nucl-thhep-phnucl-exLect.Notes Phys.(2021)·64 citations
10. 10*

    Fully-heavy tetraquark spectra and production at hadron colliders

    Ruilin Zhu🇨🇳

    Motivated by the observation of exotic structure around 6900MeV in the $J/\psi$-pair mass spectrum using proton-proton collision data by the LHCb collaboration, we study the spectra of fully-heavy tetraquarks within Bethe-Salpeter equation and Regge trajectory relation. The $X(6900)$ may be explained as a radially excited state with quark content $cc\bar{c}\bar{c}$ and spin-parity $0^{++}(3S)$ or $2^{++}(3S)$ or an orbitally excited $2P$ state. New $cc\bar{c}\bar{c}$ structures around 6.0GeV, 6.5GeV, and 7.1GeV are predicted together. Other $bb\bar{b}\bar{b}$ and $bc\bar{b}\bar{c}$ structures which may be experimentally prominent are discussed. On the other hand, the fully-heavy S-wave tetraquark productions at hadron colliders are investigated and their cross-sections are obtained.

    ↳ hep-phhep-exnucl-exNPB(2021)·120 citations
11. 11*

    Topmetal CMOS direct charge sensing plane for neutrinoless double-beta decay search in high-pressure gaseous TPC

    Yuan Mei🇺🇸 · Xiangming Sun🇨🇳 · Nu Xu🇺🇸

    We propose a novel charge sensing concept for high-pressure Time Projection Chamber (TPC) to search for Neutrinoless Double-Beta Decay (NLDBD) with ton-scale isotope mass and beyond. A meter-sized plane, tiled with an array of CMOS integrated sensors called Topmetal that directly collect charge without gas avalanche gain, is to be deployed into a high-pressure gaseous TPC with working gases containing suitable NLDBD candidate isotopes such as Xe-136 and Se-82. The Topmetal sensor has an electronic noise <30 e- per pixel, which allows the detector to reach <1% FWHM energy resolution at the NLDBD Q-value for both Xe-136 and 82SeF6 gases by measuring ionization charges alone. The elimination of charge avalanche gain allows the direct sensing of slow-drifting ions, which enables the use of highly electronegative gas SeF6 in which free electrons do not exist. It supports the swapping of working gases without hardware modification, which is a unique way to validate signals against radioactive backgrounds. Since the sensor manufacturing and plane assembling could leverage unaltered industrial mass-production processes, stability, uniformity, scalability, and cost-effectiveness that are required for ton-scale experiments could all be reached. The strengths of TPC such as 3D ionization tracking and decay daughter tagging are retained. This development could lead to a competitive NLDBD experiment at and above ton-scale. The conceptual considerations, simulations, and initial prototyping are discussed.

    ↳ physics.ins-dethep-exnucl-ex6 citations
12. 12*

    Hidden spin-isospin exchange symmetry

    Dean Lee🇺🇸 · Scott Bogner🇺🇸 · B. Alex Brown🇺🇸 · Serdar Elhatisari🇹🇷 · Evgeny Epelbaum🇩🇪 · Heiko Hergert🇺🇸 · Morten Hjorth-Jensen🇺🇸 · Hermann Krebs🇩🇪 · Ning Li🇨🇳 · Bing-Nan Lu🇺🇸 · Ulf-G. Meißner🇩🇪

    The strong interactions among nucleons have an approximate spin-isospin exchange symmetry that arises from the properties of quantum chromodynamics in the limit of many colors, $N_c$. However this large-$N_c$ symmetry is well hidden and reveals itself only when averaging over intrinsic spin orientations. Furthermore, the symmetry is obscured unless the momentum resolution scale is close to an optimal scale that we call ${\Lambda }_{\mathrm{large}-N_c}$. We show that the large-$N_c$ derivation requires a momentum resolution scale of ${\Lambda }_{\mathrm{large}-N_c}\sim 500$ MeV. We derive a set of spin-isospin exchange sum rules and discuss implications for the spectrum of ${}^{30}$P and applications to nuclear forces, nuclear structure calculations, and three-nucleon interactions.

    ↳ nucl-thhep-lathep-phnucl-exPRL(2021)·35 citations
13. 13*

    On the width of the $K^{-}$D atom ground state

    N. Barnea🇮🇱 · E. Friedman🇮🇱 · A. Gal🇮🇱

    Experiments at DA$\Phi$NE-Frascati and at J-PARC are scheduled to produce $K^{-}$D atoms and observe their X-ray cascade down to the 1$S$ ground state (g.s.), thereby measuring its strong-interaction width and shift away from a purely Coulomb state. A width ${\Gamma }_{1S}\lesssim 1$ keV will ensure good resolution of the X-ray transitions feeding the 1$S$ g.s. Here we study the expected $K^{-}$D 1$S$ g.s. width from the perspective of global fits to level shifts and widths in heavier kaonic atoms across the periodic table, using $K^{-}$ nuclear optical potentials constructed from $\bar{K}N$ chiral interaction models. Special attention is paid to the subthreshold energy at which the $\bar{K}N$ subsystem interacts in the $K^{-}$D atomic g.s. Within this approach we predict strong-interaction upward level shift of close to 700 eV and width of about 1.2 to 1.3 keV for the $K^{-}$D atom 1$S$ g.s., in fair agreement with genuinely three-body $K^{-}$D atom calculations. Comparison is made with ${\pi }^{-}$D atom phenomenology.

    ↳ nucl-thhep-phnucl-exNPA(2021)·2 citations
14. 14*

    Beam spin asymmetry in semi-inclusive electroproduction of a hadron pair

    M. Mirazita🇮🇹 · H. Avakian🇺🇸 · A. Courtoy🇲🇽 · S. Pisano🇮🇹 · S. Adhikari🇺🇸 · M.J. Amaryan🇺🇸 · G. Angelini🇺🇸 · H. Atac🇺🇸 · N.A. Baltzell🇺🇸 · L. Barion🇮🇹 · M. Battaglieri🇺🇸 · I. Bedlinskiy🇷🇺 and 131 other authors

    A first measurement of the longitudinal beam spin asymmetry ALU in the semi-inclusive electroproduction of pairs of charged pions is reported. ALU is a higher-twist observable and offers the cleanest access to the nucleon twist-3 parton distribution function e(x). Data have been collected in the Hall-B at Jefferson Lab by impinging a 5.498 GeV electron beam on a liquid-hydrogen target, and reconstructing the scattered electron and the pion pair with the CLAS detector. One-dimensional projections of the sin(phiR) moments of ALU are extracted for the kinematic variables of interest in the valence quark region. The understanding of di-hadron production is essential for the interpretation of observables in single hadron production in semi-inclusive DIS, and pioneering measurements of single spin asymmetries in di-hadron production open a new avenue in studies of QCD dynamics.

    ↳ hep-exnucl-exPRL(2021)·16 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.