Mon·Nov 6, 2017Monday·November 6, 2017

1. 01*

   Isospin Dependence of the EMC effect and Short range Correlations

   B. Schmookler🇺🇸 · M. Duer🇮🇱 · A. Schmidt🇺🇸 · S. Gilad🇺🇸 · L.B. Weinstein🇺🇸 · E. Piasetzky🇮🇱 · O. Hen🇺🇸

   Recent studies have shown that the per-nucleon number of Short-Range Correlated (SRC) pairs in nuclei and the strength of the EMC effect are linearly correlated, increasing from light nuclei up to iron and then saturating. This paper shows that the per-proton number of SRC pairs and the strength of the EMC effect are linearly correlated and increase from light to heavy asymmetric neutron-rich nuclei without saturation. These quantities, calculated per neutron, are also linearly related, but saturate (have constant value) remarkably early, starting with 12C. We propose that the observed phenomenological relationships indicate an isospin dependence of the EMC effect which is associated with the dominance of SRCs by neutron-proton pairs from 3He to heavy asymmetric neutron-rich nuclei.

   nucl-exnucl-th0 citations
2. 02*

   First measurement of coherent $\varphi$-meson photoproduction from helium-4 near threshold

   LEPS Collaboration: T. Hiraiwa🇯🇵 · M. Yosoi🇯🇵 · M. Niiyama🇯🇵 · Y. Morino🇯🇵 · Y. Nakatsugawa🇨🇳 · M. Sumihama🇯🇵 · D. S. Ahn🇯🇵 · J. K. Ahn🇰🇷 · W. C. Chang🇹🇼 · J. Y. Chen🇹🇼 · S. Daté🇯🇵 · H. Fujimura🇯🇵 and 32 other authors

   The differential cross sections and decay angular distributions for coherent $\varphi$-meson photoproduction from helium-4 have been measured for the first time at forward angles with linearly polarized photons in the energy range $E_{\gamma }=\text{1.685-2.385 GeV}$. Thanks to the target with spin-parity $J^P=0^{+}$, unnatural-parity exchanges are prohibited, and thus natural-parity exchanges can be investigated clearly. The decay asymmetry with respect to photon polarization is shown to be very close to the maximal value. This ensures the dominance ($>94\%$) of natural-parity exchanges in this reaction. To evaluate the contribution from natural-parity exchanges to the forward cross section ($\theta =0^{\circ }$) for the $\gamma p\to \varphi p$ reaction near the threshold, the energy dependence of the forward cross section ($\theta =0^{\circ }$) for the $\gamma {}^4\text{He}\to \varphi {}^4\text{He}$ reaction was analyzed. The comparison to $\gamma p\to \varphi p$ data suggests that enhancement of the forward cross section arising from natural-parity exchanges, and/or destructive interference between natural-parity and unnatural-parity exchanges is needed in the $\gamma p\to \varphi p$ reaction near the threshold.

   nucl-exPRC(2018)·19 citations
3. 03*

   Low background techniques in bolometers for double-beta decay search

   Denys Poda🇺🇦 · Andrea Giuliani🇫🇷

   Bolometers are low temperature particle detectors with high energy resolution and detection efficiency. Some types of bolometric detectors are also able to perform an efficient particle identification. A wide variety of radiopure dielectric and diamagnetic materials makes the bolometric technique favorable for applications in astroparticle physics. In particular, thanks to their superior performance, bolometers play an important role in the world-wide efforts on searches for neutrinoless double-beta decay. Such experiments strongly require an extremely low level of the backgrounds that can easily mimic the process searched for. Here we overview recent progress in the development of low background techniques for bolometric double-beta decay searches.

   ↳ physics.ins-dethep-exnucl-exInt.J.Mod.Phys.A(2017)·58 citations
4. 04*

   Evaluation of the hyperon binding energy via statistical production of hypernuclei

   A.S. Botvina · M. Bleicher · N. Buyukcizmeci

   In nuclear reactions of high energy one can simultaneously produce a lot of hypernuclei after the capture of hyperons by nuclear residues. We consider statistical disintegration of such hypernuclear systems and the connection of fragment production with the binding energies of hyperons. It is demonstrated that the hyperon binding energies can be effectively evaluated from the yields of different isotopes of hypernuclei. The double ratio method is suggested for this purpose. The advantage of this procedure is its universality and the possibility to involve many different isotopes. This method can also be applied for multi-strange nuclei, which binding energies were very difficult to measure in previous hypernuclear experiments.

   ↳ nucl-thnucl-exPRC(2018)·16 citations
5. 05*

   The ALICE trigger system for LHC Run 3

   M. Krivda🇬🇧 · D. Evans🇬🇧 · K.L. Graham🇬🇧 · A. Jusko🇬🇧 · R. Lietava🇬🇧 · O. Villalobos Baillie🇬🇧 · N.Zardoshti🇬🇧 · M. Bombara🇸🇰 · M. Sefcik🇸🇰 · I Kralik🇸🇰 · L.A. Perez Moreno (for the ALICE Collaboration)🇲🇽

   The ALICE Central Trigger Processor (CTP) is going to be upgraded for LHC Run 3 with completely new hardware and a new Trigger and Timing Control (TTC-PON) system based on a Passive Optical Network (PON) system. The new trigger system has been designed as dead time free and able to transmit trigger data at 9.6 Gbps. A new universal trigger board has been designed, where by changing the FMC card, it can function as a CTP or as a LTU. It is based on the Xilinx Kintex Ultrascale FPGA and upgraded TTC-PON. The new trigger system and the prototype of the trigger board will be presented.

   ↳ physics.ins-detnucl-exPoS(2017)·3 citations
6. 06*

   A Model for the Global Quantum Efficiency for a TPB-based Wavelength-Shifting System used with Photomultiplier Tubes in Liquid Argon in MicroBooNE

   S.F. Pate🇺🇸 · T. Wester🇺🇸 · L. Bugel🇺🇸 · J. Conrad🇺🇸 · E. Henderson🇺🇸 · B.J.P. Jones🇺🇸 · A.I.L. McLean🇺🇸 · J.S. Moon🇺🇸 · M. Toups🇺🇸 · T. Wongjirad🇺🇸

   We present a model for the Global Quantum Efficiency (GQE) of the MicroBooNE optical units. An optical unit consists of a flat, circular acrylic plate, coated with tetraphenyl butadiene (TPB), positioned near the photocathode of a 20.2-cm diameter photomultiplier tube. The plate converts the ultra-violet scintillation photons from liquid argon into visible-spectrum photons to which the cryogenic phototubes are sensitive. The GQE is the convolution of the efficiency of the plates that convert the 128 nm scintillation light from liquid argon to visible light, the efficiency of the shifted light to reach the photocathode, and the efficiency of the cryogenic photomultiplier tube. We develop a GEANT4-based model of the optical unit, based on first principles, and obtain the range of probable values for the expected number of detected photoelectrons ($N_{\mathrm{PE}}$) given the known systematic errors on the simulation parameters. We compare results from four measurements of the $N_{\mathrm{PE}}$ determined using alpha-particle sources placed at two distances from a TPB-coated plate in a liquid argon cryostat test stand. We also directly measured the radial dependence of the quantum efficiency, and find that this has the same shape as predicted by our model. Our model results in a GQE of $0.0055\pm 0.0009$ for the MicroBooNE optical units. While the information shown here is MicroBooNE specific, the approach to the model and the collection of simulation parameters will be widely applicable to many liquid-argon-based light collection systems.

   ↳ physics.ins-dethep-exnucl-exJINST(2018)·5 citations
7. 07*

   Baryon interactions from lattice QCD with physical quark masses -- Nuclear forces and $\Xi \Xi$ forces --

   Takumi Doi🇯🇵 · Takumi Iritani🇯🇵 · Sinya Aoki🇯🇵 · Shinya Gongyo🇯🇵 · Tetsuo Hatsuda🇯🇵 · Yoichi Ikeda🇯🇵 · Takashi Inoue🇯🇵 · Noriyoshi Ishii🇯🇵 · Takaya Miyamoto🇯🇵 · Hidekatsu Nemura🇯🇵 · Kenji Sasaki🇯🇵

   We present the latest lattice QCD results for baryon interactions obtained at nearly physical quark masses. $N_f=2+1$ nonperturbatively $\mathcal{O}(a)$-improved Wilson quark action with stout smearing and Iwasaki gauge action are employed on the lattice of $(96a{)}^4\simeq (8.1\text{mbox}fm{)}^4$ with $a^{-1}\simeq 2.3$ GeV, where $m_{\pi }\simeq 146$ MeV and $m_K\simeq 525$ MeV. In this report, we study the two-nucleon systems and two-$\Xi$ systems in ${}^1{S}_0$ channel and ${}^3{S}_1$-${}^3{D}_1$ coupled channel, and extract central and tensor interactions by the HAL QCD method. We also present the results for the $N\Omega$ interaction in ${}^5{S}_2$ channel which is relevant to the $N\Omega$ pair-momentum correlation in heavy-ion collision experiments.

   ↳ hep-lathep-phnucl-exnucl-thEPJ Web Conf.(2018)·39 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.