# Nuclear Experiment

## New submissions

[ total of 11 entries: 1-11 ]
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### New submissions for Thu, 23 Nov 17

[1]
Title: A new scheme to measure the electron-neutrino correlation - the case of $^{6}$He
Authors: I. Mukul (1), M. Hass (1), O. Heber (1), T. Y. Hirsh (2), Y. Mishnayot (1,2,3), M. L. Rappaport (1), G. Ron (3), Y. Shachar (1), S. Vaintraub (2) ((1) Weizmann Institute of Science, (2) Soreq Nuclear Research Center and (3) Hebrew University of Jerusalem)
Subjects: Nuclear Experiment (nucl-ex); Instrumentation and Detectors (physics.ins-det)

A novel experiment has been commissioned at the Weizmann Institute of Science for the study of weak interactions via a high-precision measurement of the beta-neutrino angular correlation in the radioactive decay of short-lived $^{6}$He. The facility consists of a 14 MeV $d+t$ neutron generator to produce atomic $^{6}$He, followed by ionization and bunching in an electron beam ion source, and injection into an electrostatic ion beam trap. This ion trap has been designed for efficient detection of the decay products from trapped light ions. The storage time in the trap for different stable ions was found to be in the range of 0.6 to 1.2 s at the chamber pressure of $\sim$7$\times$10$^{-10}$ mbar. We present the initial test results of the facility, and also demonstrate an important upgrade of an existing method \cite{stora} for production of light radioactive atoms, viz. $^{6}$He, for the precision measurement. The production rate of $^{6}$He atoms in the present setup has been estimated to be $\sim 1.45\times10^{-4}$ atoms per neutron, and the system efficiency was found to be 4.0$\pm$0.6\%. An improvement to this setup is also presented for the enhanced production and diffusion of radioactive atoms for future use.

### Cross-lists for Thu, 23 Nov 17

[2]  arXiv:1711.07773 (cross-list from nucl-th) [pdf, other]
Title: Principal component analysis of the nonlinear coupling of harmonic modes in heavy-ion collisions
Authors: Piotr Bozek
Subjects: Nuclear Theory (nucl-th); High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)

The principal component analysis of flow correlations in heavy-ion collisions is studied. The correlation matrix of harmonic flow is generalized to correlations involving several different flow vectors. The method can be applied to study the nonlinear coupling between different harmonic modes in a double differential way in transverse momentum or pseudorapidity. The procedure is illustrated with results from the hydrodynamic model applied to Pb+Pb collisions at $\sqrt{s}=2760$GeV. Three examples of generalized correlations matrices in transverse momentum are constructed corresponding to the coupling of $v_2^2$ and $v_4$, of $v_2v_3$ and $v_5$, or of $v_2^3$, $v_3^3$, and $v_6$. The principal component decomposition is applied to the correlation matrices and the dominant modes are calculated.

[3]  arXiv:1711.07936 (cross-list from physics.ins-det) [pdf, other]
Title: Radon-free environment for the installation of the CUORE $0νββ$ decay detector
Comments: 10 pages, 7 figures, prepared for submission to JINST
Subjects: Instrumentation and Detectors (physics.ins-det); Nuclear Experiment (nucl-ex)

CUORE - the Cryogenic Underground Observatory for Rare Events - is an experiment searching for the neutrinoless double-beta ($0\nu\beta\beta$) decay of $^{130}$Te with an array of 988 TeO$_2$ crystals operated as bolometers at $\sim$10 mK in a large dilution refrigerator. With this detector, we aim for a $^{130}$Te $0\nu\beta\beta$ decay half-life sensitivity of $9\times10^{25}$ y with 5 y of live time, and a background index of $\lesssim 10^{-2}$ counts/keV/kg/y. Making an effort to maintain radiopurity by minimizing the bolometers' exposure to radon gas during their installation in the cryostat, we perform all operations inside a dedicated cleanroom environment with a controlled radon-free atmosphere. In this paper, we discuss the design and performance of the CUORE Radon Abatement System and cleanroom, as well as a system to monitor the radon level in real time.

[4]  arXiv:1711.07959 (cross-list from nucl-th) [pdf, other]
Title: Three-fluid Hydrodynamics-based Event Simulator Extended by UrQMD final State interactions (THESEUS) for FAIR-NICA-SPS-BES/RHIC energies
Comments: 12 pp., 9 figs. Proceedings of 6th Int. Conf. on New Frontiers in Physics (ICNFP 2017), August 17-26, 2017, Kolymbari, Crete, Greece
Subjects: Nuclear Theory (nucl-th); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)

We present a new event generator based on the three-fluid hydrodynamics (3FH) approach, followed by a particlization at the hydrodynamic decoupling surface and a subsequent UrQMD afterburner stage based on the microscopic UrQMD transport model that accounts for hadronic final state interactions. First results for Au+Au collisions are presented. The following topics are addressed: the directed flow, transverse-mass spectra, as well as rapidity distributions of protons, pions and kaons for two model equations of state, one with a first-order phase transition, the other with a crossover transition. Preliminary results on the femtoscopy are also discussed. We analyze the accuracy of reproduction of the 3FH results by the new event generator and the effect of the subsequent UrQMD afterburner stage.

[5]  arXiv:1711.08119 (cross-list from hep-ex) [pdf, other]
Title: Measurement of the multi-TeV neutrino cross section with IceCube using Earth absorption
Comments: Preprint version of Nature paper 10.1038/nature24459
Subjects: High Energy Physics - Experiment (hep-ex); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)

Neutrinos interact only very weakly, so they are extremely penetrating. However, the theoretical neutrino-nucleon interaction cross section rises with energy such that, at energies above 40 TeV, neutrinos are expected to be absorbed as they pass through the Earth. Experimentally, the cross section has been measured only at the relatively low energies (below 400 GeV) available at neutrino beams from accelerators \cite{Agashe:2014kda, Formaggio:2013kya}. Here we report the first measurement of neutrino absorption in the Earth, using a sample of 10,784 energetic upward-going neutrino-induced muons observed with the IceCube Neutrino Observatory. The flux of high-energy neutrinos transiting long paths through the Earth is attenuated compared to a reference sample that follows shorter trajectories through the Earth. Using a fit to the two-dimensional distribution of muon energy and zenith angle, we determine the cross section for neutrino energies between 6.3 TeV and 980 TeV, more than an order of magnitude higher in energy than previous measurements. The measured cross section is $1.30^{+0.21}_{-0.19}$ (stat.) $^{+0.39}_{-0.43}$ (syst.) times the prediction of the Standard Model \cite{CooperSarkar:2011pa}, consistent with the expectation for charged and neutral current interactions. We do not observe a dramatic increase in the cross section, expected in some speculative models, including those invoking new compact dimensions \cite{AlvarezMuniz:2002ga} or the production of leptoquarks \cite{Romero:2009vu}.

[6]  arXiv:1711.08354 (cross-list from hep-ph) [pdf, other]
Title: Pion Condensation by Rotation in a Magnetic field
Comments: 5 pages, 2 figures. arXiv admin note: text overlap with arXiv:1710.02895
Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)

We show that the combined effects of a rotation plus a magnetic field can cause charged pion condensation. We suggest that this phenomenon may yield to observable effects in current heavy ion collisions at collider energies, where large magnetism and rotations are expected in off-central collisions.

### Replacements for Thu, 23 Nov 17

[7]  arXiv:1705.01460 (replaced) [pdf, other]
Title: Coherent J/$ψ$ photoproduction in hadronic heavy-ion collisions
Subjects: Nuclear Theory (nucl-th); High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
[8]  arXiv:1711.06891 (replaced) [pdf, other]
Title: Lévy analysis of HBT correlation functions in $\sqrt{s_{\rm NN}}=$ 62 GeV and 39 GeV Au+Au collisions at PHENIX
Comments: Presented at the 10th Bolyai-Gauss-Lobachevsky Conference on Non-Euclidean Geometry and its Applications
Subjects: Nuclear Experiment (nucl-ex)
[9]  arXiv:1212.0332 (replaced) [pdf, ps, other]
Title: Neutron Beta-Decay as Laboratory for Test of Standard Model
Comments: 59 pages, 3 figures and 1 Table. Some misprints are corrected, and the values of X- and Y-integrals in Appendix I are updated
Journal-ref: Phys.Rev. D88, 073002 (2013)
Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); Nuclear Experiment (nucl-ex)
[10]  arXiv:1612.02767 (replaced) [pdf, other]
Title: Medium effects in $ΛK^+$ pair production by 2.83 GeV protons on nuclei