Tue·Jan 29, 2019Tuesday·January 29, 2019

1. 01*

   Rare Low-Energy Event Searches with the Majorana Demonstrator

   Gulden Othman (on behalf of the Majorana Collaboration)🇺🇸

   The Majorana Demonstrator is currently searching for neutrinoless double-beta decay in ${}^{76}$Ge and will demonstrate the feasibility to deploy a tonne-scale experiment in a phased and modular fashion. It consists of two modular arrays of natural and ${}^{76}$Ge-enriched germanium detectors totaling 44.1 kg, of which 29.7 kg is enriched, located at the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota, USA. The low-backgrounds and low trigger thresholds ($<$1 keV) achieved by the Demonstrator allow for additional rare-event searches at low-energies, e.g. searches for WIMPs, bosonic dark matter, and solar axions. In this work, we will present results and ongoing efforts related to these rare-event searches and discuss the future reach of Majorana.

   nucl-exphysics.ins-det0 citations
2. 02*

   Neutron skin and signature of the $N$ = 14 shell gap found from measured proton radii of ${}^{17-22}$N

   S. Bagchi🇨🇦 · R. Kanungo🇨🇦 · W. Horiuchi🇯🇵 · G. Hagen🇺🇸 · T. D. Morris🇺🇸 · S. R. Stroberg🇨🇦 · T. Suzuki🇯🇵 · F. Ameil🇩🇪 · J. Atkinson🇩🇪 · Y. Ayyad🇯🇵 · D. Cortina-Gil🇪🇸 · I. Dillmann🇨🇦 and 28 other authors

   A thick neutron skin emerges from the first determination of root mean square radii of the proton distributions for ${}^{17-22}$N from charge changing cross section measurements around 900$A$ MeV at GSI. Neutron halo effects are signaled for ${}^{22}$N from an increase in the proton and matter radii. The radii suggest an unconventional shell gap at $N$ = 14 arising from the attractive proton-neutron tensor interaction, in good agreement with shell model calculations. $Ab$ $initio$, in-medium similarity re-normalization group, calculations with a state-of-the-art chiral nucleon-nucleon and three-nucleon interaction reproduce well the data approaching the neutron drip-line isotopes but are challenged in explaining the complete isotopic trend of the radii.

   nucl-exnucl-thPLB(2019)·55 citations
3. 03*

   Probing nuclear bubble configuration by proton induced reaction

   Xiao-Hua Fan🇨🇳 · Gao-Chan Yong🇨🇳 · Wei Zuo🇨🇳

   In the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, nuclear bubble configuration in the hypothetical ${}^{48}$Si nucleus is studied by proton induced central reaction at an incident beam energy of 0.8 GeV/nucleon. It is found that along the beam direction more energetic protons are emitted with bubble configuration in the target. In the forward angles, compared with the case without bubble configuration, less scattered energetic protons are emitted with bubble configuration in the target. We thus provide a new way to probe the bubble configuration in nuclei.

   ↳ nucl-thnucl-exPRC(2019)·16 citations
4. 04*

   Elastic proton-proton scattering at LHC energies in holographic QCD

   Wei Xie🇨🇳 · Akira Watanabe🇨🇳 · Mei Huang🇨🇳

   The cross sections of the high energy proton-proton scattering are studied in a holographic QCD model, focusing on the Regge regime. In our model setup, the involved nonperturbative partonic dynamics is described by the Pomeron exchange, which is realized by applying the Reggeized spin-2 particle propagator together with the proton gravitational form factor obtained from the bottom-up AdS/QCD model. Our model includes three adjustable parameters which are to be fitted by experimental data. We show that both the resulting differential and total cross sections are consistent with data, including the ones recently measured at $\sqrt{s}=13$ TeV by the TOTEM collaboration at the LHC. Our results imply that the present framework works well in the considered TeV scale, and further applications to other high energy scattering processes, in which the involved strong interaction can be approximated by the Pomeron exchange, are possible.

   ↳ hep-phhep-thnucl-exnucl-thJHEP(2019)·26 citations
5. 05*

   Charmed nuclei within a microscopic many-body approach

   I. Vidana🇮🇹 · A. Ramos🇪🇸 · C. E. Jimenez-Tejero🇪🇸

   Single-particle energies of the ${\Lambda }_c$ chamed baryon are obtained in several nuclei from the relevant self-energy constructed within the framework of a perturbative many-body approach. Results are presented for a charmed baryon-nucleon ($Y_{c}N$) potential based on a SU(4) extension of the meson-exchange hyperon-nucleon potential $\tilde{A}$ of the Jülich group. Three different models (A, B and C) of this interaction, that differ only on the values of the couplings of the scalar $\sigma$ meson with the charmed baryons, are considered. Phase shifts, scattering lengths and effective ranges are computed for the three models and compared with those predicted by the $Y_{c}N$ interaction derived in Eur. Phys. A {\bf 54}, 199 (2018) from the extrapolation to the physical pion mass of recent results of the HAL QCD Collaboration. Qualitative agreement is found for two of the models (B and C) considered. Our results for ${\Lambda }_c$-nuclei are compatible with those obtained by other authors based on different models and methods. We find a small spin-orbit splitting of the $p-,d-$ and $f-$wave states as in the case of single $\Lambda$-hypernuclei. The level spacing of ${\Lambda }_c$ single-particle energies is found to be smaller than that of the corresponding one for hypernuclei. The role of the Coulomb potential and the effect of the coupling of the ${\Lambda }_{c}N$ and ${\Sigma }_{c}N$ channels on the single-particle properties of ${\Lambda }_c-$nuclei are also analyzed. Our results show that, despite the Coulomb repulsion between the ${\Lambda }_c$ and the protons, even the less attractive one of our $Y_{c}N$ models (model C) is able to bind the ${\Lambda }_c$ in all the nuclei considered. The effect of the ${\Lambda }_{c}N-{\Sigma }_{c}N$ coupling is found to be almost negligible due to the large mass difference of the ${\Lambda }_c$ and ${\Sigma }_c$ baryons.

   ↳ nucl-thhep-phnucl-exPRC(2019)·16 citations
6. 06*

   Phenomenological NLO analysis of eta(c) production at the LHC in the collider and fixed-target modes

   Yu Feng🇨🇳 · Jibo He🇨🇳 · Jean-Philippe Lansberg🇫🇷 · Hua-Sheng Shao🇫🇷 · Andrii Usachov🇫🇷 · Hong-Fei Zhang🇨🇳

   In view of the good agreement between the LHCb prompt-eta(c) data at sqrt(s)=7 and 8 TeV and the NLO colour-singlet model predictions --i.e. the leading v^2 NRQCD contribution--, we provide predictions in the LHCb acceptance for the forthcoming 13 TeV analysis bearing on data taken during the LHC Run2. We also provide predictions for sqrt(s)=115 GeV for proton-hydrogen collisions in the fixed-target mode which could be studied during the LHC Run3. Our predictions are complemented by a full theoretical uncertainty analysis. In addition to cross section predictions, we elaborate on the uncertainties on the p bar-p branching ratio --necessary for data-theory comparison-- and discuss other usable branching fractions for future studies.

   ↳ hep-phhep-exnucl-exnucl-thNPB(2019)·28 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.