Tue·Jun 27, 2023Tuesday·June 27, 2023

1. 01*

   First Results on Nucleon Resonance Electroexcitation Amplitudes from $ep\to e^{\prime }{\pi }^{+}{\pi }^{-}{p}^{\prime }$ Cross Sections at $W$ from 1.4-1.7 GeV and $Q^2$ from 2.0-5.0 GeV${}^2$

   V. I. Mokeev🇺🇸 · P. Achenbach🇺🇸 · V. D. Burkert🇺🇸 · D. S. Carman🇺🇸 · R. W. Gothe🇺🇸 · A. N. Hiller Blin🇩🇪 · E. L. Isupov🇷🇺 · K. Joo🇺🇸 · K. Neupane🇺🇸 · A. Trivedi🇺🇸

   The electroexcitation amplitudes or ${\gamma }_{v}p{N}^{\ast }$ electrocouplings of the $N(1440)1/2^{+}$, $N(1520)3/2^{-}$, and $\Delta (1600)3/2^{+}$ resonances were obtained for the first time from the $ep\to e^{\prime }{\pi }^{+}{\pi }^{-}{p}^{\prime }$ differential cross sections measured with the CLAS detector at Jefferson Lab within the range of invariant mass $W$ of the final state hadrons from 1.4--1.7 GeV for photon virtualities $Q^2$ from 2.0--5.0 GeV${}^2$. The electrocouplings were determined in independent fits of the ${\pi }^{+}{\pi }^{-}p$ cross sections within three overlapping $W$ intervals with a substantial contribution from each of the three resonances listed above. Consistent results on the electrocouplings extracted from the data in these $W$ intervals provide evidence for their reliable extraction. These studies extend information on the electrocouplings of the $N(1440)1/2^{+}$ and $N(1520)3/2^{-}$ available from this channel over a broader range of $Q^2$. The electrocouplings of the $\Delta (1600)3/2^{+}$, which decays preferentially into $\pi \pi N$ final states, have been determined for the first time. Our results provide further evidence for the structure of these resonances in terms of an interplay between the inner core of three dressed quarks and an external meson-baryon cloud.

   nucl-exhep-phPRC(2023)·38 citations
2. 02*

   Understanding Excitations in ${}^{59,61}$Co, ${}^{59}$Ni

   Samuel Ajayi🇺🇸 · Vandana Tripathi🇮🇳 · E. Rubino🇺🇸 · Soumik Bhattacharya🇮🇳 · L. T. Baby🇺🇸 · R. S. Lubna🇺🇸 · C. Benetti · Catur Wibisono🇺🇸 · MacMillan B. Wheeler · S. L. Tabor · Yutaka Utsuno🇯🇵 · Noritaka Shimizu🇯🇵 · J. M. Allmond🇺🇸

   High spin states in ${}^{59}$Co ($Z=27$), ${}^{59}$Ni ($Z=28$) and ${}^{61}$Co have been populated by the fusion evaporation reactions, ${}^{48}$Ti(${}^{14}$C, p2n)${}^{59}$Co, ${}^{48}$Ti(${}^{14}$C, 3n)${}^{59}$Ni, and ${}^{50}$Ti(${}^{14}$C, p2n)${}^{61}$Co. The 9 MV tandem accelerator at the John D Fox Laboratory, Florida State University (FSU) was used to accelerate the ${}^{14}$C beam and the de-exciting $\gamma$ rays were detected by the FSU detector array consisting of six High Purity Germanium (HPGe) clover detectors, and three single crystals. Directional correlation of the $\gamma$ rays de-exciting oriented states (DCO ratios) and polarization asymmetry measurements helped to establish spin and parities of the excited states whenever possible. The level scheme of ${}^{59}$Co has been expanded with the inclusion of positive parity states up to 31/2${}^{+}$ at around 11 MeV. The ${}^{59}$Ni positive parity states known from previous study were verified with modifications to some of the spins and parities. On the other hand, the negative parity states were extended to 31/2 at an excitation energy of 12 MeV. No new transition was observed for ${}^{61}$Co, but one of the major bands has been reassigned as consisting of positive parity states by reason of this study which is a candidate for magnetic rotation band. Cross shell excitations were observed in the three nuclei studied and the prominent role of excitation to g${}_{9/2}$ orbital crossing the $N=40$ shell gap was established in relation to collective excitation in these nuclei by comparison with large-scale shell model calculations.

   nucl-exnucl-th0 citations
3. 03*

   Top quark and vector meson production in heavy ion collisions at CMS

   Luis F. Alcerro🇺🇸

   Heavy ion collisions are rich and complex systems that involve different aspects of QCD and electromagnetic phenomena. From head-on collisions to the case in which the nuclei miss each other, many of QCD and photo-induced probes are being actively investigated. In this contribution we briefly discuss both of these different topics and some of the CMS results on top quark production and vector meson photo-production, as well as the physics motivation to study these processes are presented.

   nucl-exhep-exRev.Mex.Fis.Suppl.(2023)·0 citations
4. 04*

   Dipion and dikaon photoproduction in ultra-peripheral Pb-Pb collisions with ALICE

   Abdennacer Hamdi🇺🇸

   High energy photons originating from the electromagnetic field of ultrarelativistic lead nuclei can interact with the other lead ion. These reactions are studied in the ultra-peripheral heavy ion collisions to probe the physics of strong interactions. The analysis of dipion and dikaon photoproduction was carried out using the ALICE 2015 Pb-Pb data at center-of-mass energy $\sqrt{s}=5.02$ TeV, and 2017 Xe-Xe data at $\sqrt{s}=5.44$ TeV. We present the ${\rho }^0$ meson and direct ${\pi }^{+}{\pi }^{-}$ measurements, as well as the prospects of studying exclusive $K^{+}{K}^{-}$ photoproduction, with sensitivity towards higher dikaon invariant mass above the $\varphi (1020)$ threshold.

   nucl-exhep-ex0 citations
5. 05*

   Measurement of the 2$\nu \beta \beta$ Decay Half-Life of Se-82 with the Global CUPID-0 Background Model

   O. Azzolini🇮🇹 · J. W. Beeman🇺🇸 · F. Bellini🇮🇹 · M. Beretta🇺🇸 · M. Biassoni🇮🇹 · C. Brofferio🇮🇹 · C. Bucci🇮🇹 · S. Capelli🇮🇹 · V. Caracciolo🇮🇹 · L. Cardani🇮🇹 · P. Carniti🇮🇹 · N. Casali🇮🇹 and 40 other authors

   We report on the results obtained with the global CUPID-0 background model, which combines the data collected in the two measurement campaigns for a total exposure of 8.82~kg$\times$yr of ${}^{82}$Se. We identify with improved precision the background sources within the 3 MeV energy region, where neutrinoless double $\beta$-decay of ${}^{82}$Se and ${}^{100}$Mo is expected, making more solid the foundations for the background budget of the next-generation CUPID experiment. Relying on the excellent data reconstruction, we measure the two-neutrino double $\beta$-decay half-life of ${}^{82}$Se with unprecedented accuracy: $T_{1/2}^{2\nu }=[8.69\pm 0.05\text{(stat.)}{}_{-0.06}^{+0.09}\text{(syst.)}]\times 10^{19}\text{yr}$.

   nucl-exPRL(2023)·19 citations
6. 06*

   Electromagnetic Transition Form Factors of Baryon Resonances

   G. Ramalho🇰🇷 · M.T. Peña🇵🇹

   Recent experimental and theoretical advancements have led to significant progress in our understanding of the electromagnetic structure of nucleons ($N$), nucleon excitations ($N^{\ast }$), and other baryons. These breakthroughs have been made possible by the capabilities of modern facilities, enabling the induction of photo- and electro-excitation of nucleon resonances. Recent experimental advances have sparked notable developments in theoretical approaches. New theoretical methods have been tested and proven to be robust, marking the beginning of a new era in our understanding on baryons. We present a comprehensive review of progress in experimental data on ${\gamma }^{\ast }N\to N^{\ast }$ reactions. Additionally, we discuss various analyses and theoretical results. Some of these methods have matured in their predictive power, offering new perspectives on exotic hadrons with multiquark components. We place special emphasis on both the low-$Q^2$ and large-$Q^2$ regions to reinforce crucial physical constraints on observables that hold in these limits. Furthermore, we illustrate that the combination of lattice QCD with chiral effective field theory and quark models, respectively, proves beneficial in interpreting data and applying constraints within those different regimes. As a practical contribution and for future reference, we review the formulas for helicity amplitudes, multipole form factors and the relations between these two sets of functions for transitions to resonances with general spin $J\ge \frac{1}{2}$. These formulas are ubiquitous and play a pivotal role in experimental and theoretical studies on baryon structure. Notably, the multipole transition form factors for $J\ge \frac{3}{2}$ resonances serve as valuable tools to test perturbative QCD results in the large-$Q^2$ region, thanks to the correlations between electric and magnetic transition form factors.

   ↳ hep-phhep-exhep-latnucl-ex+1PPNP(2024)·52 citations
7. 07*

   Radiative Corrections: From Medium to High Energy Experiments

   Andrei Afanasev🇺🇸 · Jan C. Bernauer🇺🇸 · Peter Blunden🇨🇦 · Johannes Blümlein🇩🇪 · Ethan W. Cline🇺🇸 · Jan M. Friedrich🇩🇪 · Franziska Hagelstein🇩🇪 · Tomáš Husek🇸🇪 · Michael Kohl🇺🇸 · Fred Myhrer🇺🇸 · Gil Paz🇺🇸 · Susan Schadmand🇩🇪 and 7 other authors

   Radiative corrections are crucial for modern high-precision physics experiments, and are an area of active research in the experimental and theoretical community. Here we provide an overview of the state of the field of radiative corrections with a focus on several topics: lepton-proton scattering, QED corrections in deep-inelastic scattering, and in radiative light-hadron decays. Particular emphasis is placed on the two-photon exchange, believed to be responsible for the proton form-factor discrepancy, and associated Monte-Carlo codes. We encourage the community to continue developing theoretical techniques to treat radiative corrections, and perform experimental tests of these corrections.

   ↳ hep-phnucl-exnucl-thEPJA(2024)·27 citations
8. 08*

   The Entanglement of Elastic and Inelastic Scattering

   Gerald A. Miller🇺🇸

   The entanglement properties of systems in which elastic and inelastic reactions occur in projectile-target interactions is studied. A new measure of entanglement, the scattering entropy, based on the unitarity of the $S-$matrix (probability conservation), is suggested. Using simple models for both low- and high-energy interactions, the amount of entanglement is found to track with the strength of the inelastic interaction. The familiar example of the classical ``black disk", total absorption, model is found to correspond to maximum entanglement. An analysis of high-energy $pp$ scattering data shows that entanglement is near maximum for lab energies greater than about 1 GeV, showing that the total absorption model is a reasonable starting point for understanding the data.

   ↳ nucl-thhep-phnucl-exquant-phPRC(2023)·21 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.