Thu·Dec 16, 2021Thursday·December 16, 2021

1. 01*

   Polarized Structure Function ${\sigma }_{L{T}^{\prime }}$ from ${\pi }^{0}p$ Electroproduction Data in the Resonance Region at $0.4$ GeV${}^2<Q^2<1.0$ GeV${}^2$

   E.L. Isupov🇷🇺 · V.D. Burkert🇺🇸 · A.A. Golubenko🇷🇺 · K. Joo🇺🇸 · N.S. Markov🇺🇸 · V.I. Mokeev🇺🇸 · L.C. Smith🇺🇸 · W.R. Armstrong🇺🇸 · H. Atac🇺🇸 · H. Avakian🇺🇸 · N.A. Baltzell🇺🇸 · L. Barion🇮🇹 and 129 other authors

   The first results on the ${\sigma }_{L{T}^{\prime }}$ structure function in exclusive ${\pi }^{0}p$ electroproduction at invariant masses of the final state of 1.5 GeV $<$ $W$ $<$ 1.8 GeV and in the range of photon virtualities 0.4 GeV${}^2<Q^2<1.0$ GeV${}^2$ were obtained from data on beam spin asymmetries and differential cross sections measured with the CLAS detector at Jefferson Lab. The Legendre moments determined from the ${\sigma }_{L{T}^{\prime }}$ structure function have demonstrated sensitivity to the contributions from the nucleon resonances in the second and third resonance regions. These new data on the beam spin asymmetries in ${\pi }^{0}p$ electroproduction extend the opportunities for the extraction of the nucleon resonance electroexcitation amplitudes in the mass range above 1.6 GeV.

   nucl-exPRC(2022)·6 citations
2. 02*

   $\rho$ photoproduction in ALICE

   Spencer R. Klein (on behalf of the ALICE Collaboration)🇺🇸

   The ${\rho }^0$ is copiously photoproduced in ultra-peripheral heavy-ion collisions at the LHC. In this talk, I will present recent results on $\rho$ photoproduction with ALICE, including cross-section measurements from PbPb and XeXe collisions, including a discussion of the production of high-mass final states that decay to ${\pi }^{+}{\pi }^{-}$, and of neutron production that accompanies $\rho$ photoproduction. I will conclude by presenting some prospects for ALICE in Runs 3 and 4.

   nucl-exhep-ex1 citation
3. 03*

   Highlights from the NA61/SHINE strong-interactions programme

   Magdalena Kuich🇵🇱

   NA61/SHINE is a multipurpose fixed-target facility at the CERN SPS. The main goals of the NA61/SHINE strong-interactions programme are to discover the critical point of strongly interacting matter as well as to study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a function of collision energy and size of the colliding nuclei. In this contribution, the NA61/SHINE results from a strong interaction measurement programme are presented. In particular, the latest results from different reactions p+p, Be+Be, Ar+Sc, and Pb+Pb on hadron spectra, as well as intermittency, higher-order moments of multiplicity fluctuations and spectator induced electromagnetic effects are discussed.

   nucl-exhep-exEPJ Web Conf.(2022)·4 citations
4. 04*

   Constraining hadronization mechanisms with ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$/D${}^0$ production ratios in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

   ALICE Collaboration

   The production of prompt ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$ baryons at midrapidity ($|y|<0.5$) was measured in central (0-10%) and mid-central (30-50%) Pb-Pb collisions at the center-of-mass energy per nucleon-nucleon pair $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with the ALICE detector. The results are more precise, more differential in centrality, and reach much lower transverse momentum ($p_{\mathrm{T}}=1$ GeV/$c$) with respect to previous measurements performed by the ALICE, STAR, and CMS Collaborations in nucleus-nucleus collisions, allowing for an extrapolation down to $p_{\mathrm{T}}=0$. The $p_{\mathrm{T}}$-differential ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$/D${}^0$ production ratio is enhanced with respect to the pp measurement for $4<p_{\mathrm{T}}<8$ GeV/$c$ by 3.7 standard deviations ($\sigma$), while the $p_{\mathrm{T}}$-integrated ratios are compatible within 1$\sigma$. The observed trend is similar to that observed in the strange sector for the $\Lambda /$K${}_{\mathrm{S}}^0$ ratio. Model calculations including coalescence or statistical hadronization for charm-hadron formation are compared with the data.

   nucl-exhep-exPLB(2023)·104 citations
5. 05*

   Jet Charge: A new tool to probe the anomalous $Zb\bar{b}$ couplings at the EIC

   Hai Tao Li🇨🇳 · Bin Yan🇺🇸 · C.-P. Yuan🇺🇸

   We propose to utilize the average jet charge weighted single-spin asymmetry $A_e^{bQ}$ in the neutral current DIS scattering with one $b$-tagged jet produced at the EIC to probe the $Zb\bar{b}$ interactions. This novel observable is sensitive to the axial-vector component of the $Zb\bar{b}$ coupling and is complementary to the single-spin asymmetry measurement at the EIC and the $gg\to Zh$ cross section measurement at the HL-LHC in the determination of the $Zb\bar{b}$ couplings. We show that the apparent degeneracy of the $Zb\bar{b}$ couplings, implied by the LEP and SLC precision electroweak data, can be broken by the $A_e^{bQ}$ measurement at the EIC. With a large enough integrated luminosity collected at the EIC, the measurement of $A_e^{bQ}$ could also resolve the long-standing discrepancy of $A_{\mathrm{FB}}^b$ at the LEP, strongly dependent on the $b$-tagging efficiency.

   ↳ hep-phhep-exnucl-exnucl-thPLB(2022)·37 citations
6. 06*

   SPring-8 LEPS2 beamline: A facility to produce a multi-GeV photon beam via laser Compton scattering

   N. Muramatsu🇯🇵 · M. Yosoi🇯🇵 · T. Yorita🇯🇵 · Y. Ohashi🇯🇵 · J.K. Ahn🇰🇷 · S. Ajimura🇯🇵 · Y. Asano🇯🇵 · W.C. Chang🇹🇼 · J.Y. Chen🇹🇼 · S. Date🇯🇵 · T. Gogami🇯🇵 · H. Hamano🇯🇵 and 39 other authors

   We have constructed a new laser-Compton-scattering facility, called the LEPS2 beamline, at the 8-GeV electron storage ring, SPring-8. This facility provides a linearly polarized photon beam in a tagged energy range of 1.3--2.4 GeV. Thanks to a small divergence of the low-emittance storage-ring electrons, the tagged photon beam has a size (sigma) suppressed to about 4 mm even after it travels about 130 m to the experimental building that is independent of the storage ring building and contains large detector systems. This beamline is designed to achieve a photon beam intensity higher than that of the first laser-Compton-scattering beamline at SPring-8 by adopting the simultaneous injection of up to four high-power laser beams and increasing a transmittance for the long photon-beam path up to about 77%. The new beamline is under operation for hadron photoproduction experiments.

   ↳ physics.acc-phnucl-exphysics.ins-detNucl.Instrum.Meth.A(2022)·30 citations
7. 07*

   Neutrinoless double-beta decay: combining quantum Monte Carlo and the nuclear shell model with the generalized contact formalism

   Ronen Weiss🇺🇸 · Pablo Soriano🇪🇸 · Alessandro Lovato🇺🇸 · Jaview Menendez🇪🇸 · R. B. Wiringa🇺🇸

   We devise a framework based on the generalized contact formalism that combines the nuclear shell model and quantum Monte Carlo methods and compute the neutrinoless double-beta decay of experimentally relevant nuclei, including ${}^{76}$Ge, ${}^{130}$Te, and ${}^{136}$Xe. In light nuclei, we validate our nuclear matrix element calculations by comparing against accurate variational Monte Carlo results. Due to additional correlations captured by quantum Monte Carlo and introduced within the generalized contact formalism, in heavier systems, we obtain long-range nuclear matrix elements that are about 30% smaller than previous shell-model results. We also evaluate the recently recognized short-range nuclear matrix element estimating its coupling by the charge-independence-breaking term of the Argonne $v_{18}$ potential used in the Monte Carlo calculations. Our results indicate an enhancement of the total nuclear matrix element by around 30%.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2022)·50 citations
8. 08*

   On the Photoproduction Reactions $\gamma d\to \pi NN$

   William J. Briscoe (GWU)🇺🇸 · Alexander E. Kudryavtsev (ITEP)🇺🇸 · Igor I. Strakovsky (GWU)🇺🇸 · Vladimir E. Tarasov (ITEP)🇷🇺 · Ron L. Workman (GWU)🇺🇸

   A review of our works providing a theoretical description of incoherent pion photoproduction on the deuteron is presented. The existing $\gamma d\to \pi NN$ data are analysed, especially those obtained more recently by the CLAS Collaboration at JLab, the A2 Collaboration at MAMI at Mainz, and the PION@MAX-lab Collaboration at Lund. A procedure, which accounts for the final state interactions (FSI), is applied to extract $\gamma n\to \pi N$ differential cross sections from the deuteron data. The role of FSI is discussed. We also comment on the results of other works in connection with some discrepancies seen in comparing the model with experiment. The electromagnetic properties of baryon $N^{\ast }$ resonances, improved using the extracted $\gamma n\to \pi N$ differential cross sections, are presented. A model description of the cross section data from charged-pion photoproduction reactions $\gamma d\to {\pi }^{\pm }NN$ near threshold is also given. The $\gamma d\to {\pi }^{-}pp$ data are used to extract the $E_{0+}$ multipole and total crsoss sections of the reaction $\gamma n\to {\pi }^{-}p$ near threshold.

   ↳ nucl-thhep-exhep-phnucl-exEPJA(2022)·14 citations
9. 09*

   Aspects of finite temperature QCD towards the chiral limit

   Anirban Lahiri🇩🇪

   QCD under extreme conditions has been studied for a long time, and the chiral limit has been a grey area mostly. In this write-up of my talk, I review some of the recent developments made by the community to unveil various features of QCD towards the chiral limit, which includes calculation of the chiral critical temperature and determination of the order of chiral phase transition for various numbers of flavors. Acknowledging the importance of the studies regarding the effective restoration of $U_A(1)$, I try to give a comprehensive overview about the various studies done in the last few years in a comparative manner to realize the current status of the community in this regard. I also discuss very recent efforts about the relevance of various energy-like observables w.r.t. the chiral phase transition.

   ↳ hep-lathep-phnucl-exnucl-thPoS(2022)·30 citations
10. 10*

    Axion emission from nuclear magnetic dipole transitions

    R. Massarczyk🇺🇸 · P.-H. Chu🇺🇸 · S.R. Elliott🇺🇸

    Nuclear transitions are one possible source of axions but past searches were restricted to specifc transitions. In this manuscript, we propose to extend the search for axions and axion-like particles to more a complex environment that would result in a number of correlated observables. By including creation mechanisms that have their origin in the Carbon-Nitrogen-Oxygen (CNO) cycle, we show that the search for solar axions should not only be restricted to the keV-mass region. We discuss limitations, such as the lifetime and the mass, that create a challenge for an Earth-bound experiments. We show that it is possible to use the same creation mechanisms as used in solar axions to search with a comparable rate at nuclear power reactors.

    ↳ hep-phhep-exnucl-exPRD(2022)·16 citations
11. 11*

    Soft photon bremsstrahlung at next-to-leading power

    Domenico Bonocore🇩🇪 · Anna Kulesza🇩🇪

    The emission of soft radiation provides a fundamental probe of the consistency of the underlying quantum field theory. Correspondingly, the measurement of the soft photon bremsstrahlung, such as the one proposed with the planned future upgrade of the ALICE experiment at the LHC, is of great interest. In this letter we explore the possibility to implement analytic techniques that have been recently developed for soft gluon resummation at Next-to-Leading-Power (NLP) in the context of the soft photon spectrum. We provide a formula for the differential cross-section with shifted kinematics that is particularly suitable for numerical implementations. We also discuss the impact of loop corrections to Low's theorem due to radiative jet functions.

    ↳ hep-phhep-exnucl-exnucl-thPLB(2022)·20 citations
12. 12*

    Comprehensive study of muon-catalyzed nuclear reaction processes in the $dt\mu$ molecule

    M. Kamimura · Y. Kino · T. Yamashita🇯🇵

    Muon catalyzed fusion ($\mu$CF) has recently regained considerable research interest owing to several new developments and applications. In this regard, we have performed a comprehensive study of the most important fusion reaction, namely $(dt\mu {)}_{J=v=0}\to \alpha$+$n$+$\mu$+17.6 MeV or $(\alpha \mu {)}_{nl}$+$n$+17.6 MeV. The coupled-channels Schrödinger equation for the reaction is thus solved, satisfying the boundary condition for the muonic molecule $(dt\mu {)}_{\mathrm{J}=\mathrm{v}=0}$ as the initial state and the outgoing $\alpha n\mu$ channel with the $\alpha$-$n$ $D$ wave. We employ the $dt\mu$- and $\alpha n\mu$-channel coupled three-body model. All the $d$-$t$ and $\alpha$-$n$ potentials, and the $dt$-$\alpha n$ channel-coupling nonlocal tensor potential are chosen to reproduce the observed low-energy astrophysical $S$-factor of the reaction $d$+$t\to \alpha$+$n$+17.6 MeV, as well as the total cross section of the $\alpha$+$n$ reaction. The resultant $dt\mu$ fusion rate is 1.15x10${}^{12}$ s${}^{-1}$. Substituting the obtained total wave function into the $T$ matrix, we have calculated absolute values of the fusion rates going to the bound and continuum states of the outgoing $\alpha$-$\mu$ pair. We then derived the initial $\alpha$-$\mu$ sticking probability ${\omega }_S^0$=0.857%, which is $\sim$7% smaller than the literature values ($\simeq$0.91-0.93%), and can explain the recent observations (2001) at high D-T densities. We also calculate the absolute values for the momentum and energy spectra of the emitted muon. The most important result is that the peak energy is 1.1 keV although the mean energy is 9.5 keV. This is an essential result for the ongoing experimental project to realize the generation of an ultra-slow negative muon beam by utilizing the $\mu$CF for various applications e.g., a scanning negative muon microscope and an injection source for the muon collider.

    ↳ nucl-thnucl-exphysics.atom-phphysics.plasm-phPRC(2023)·12 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.