Thu·Oct 18, 2018Thursday·October 18, 2018

1. 01*

   Resonances in the solar neutrino capture cross-section for ${}^{76}Ge$ nuclei

   A.N. Fazliakhmetov🇷🇺 · L.V. Inzhechik🇷🇺 · G.A. Koroteev🇷🇺 · Yu.S. Lutostanky🇷🇺 · V.N. Tikhonov🇷🇺 · A.K. Vyborov🇷🇺

   The calculation results of solar neutrino capture cross-section on the ${}^{76}Ge$ nucleus are presented. The charge-exchange strength function $S(E)$ was obtained from the experiment data in the ${}^{76}Ge{(}^{3}He,t{)}^{76}As$ reaction. The calculation includes the effect of the resonant structure of the strength function $S(E)$ on the calculated cross section $\sigma (E_{\nu })$. It is shown that only the giant Gamow-Teller resonance contributes about 20%, and an even greater contribution is made by excited states located lower in the continuous part of the spectrum. These contributions should be taken into account in the calculation of background events in experiments on double beta decay of the GERDA type (for example LEGEND).

   nucl-exnucl-th0 citations
2. 02*

   NA61/SHINE measurements of anisotropic flow relative to the spectator plane in Pb+Pb collisions at $30$A GeV/$c$

   V. Klochkov🇩🇪 · I. Selyuzhenkov (for the NA61/SHINE Collaboration)🇷🇺

   We present an analysis of the anisotropic flow harmonics in Pb+Pb collisions at beam momenta of 30$A$ GeV/$c$ collected by the NA61/SHINE experiment in the year 2016. Directed and elliptic flow coefficients are measured relative to the spectator plane estimated with the Projectile Spectators Detector (PSD). The flow coefficients are reported as a function of transverse momentum in different classes of collision centrality. The results are compared with a new analysis of the NA49 data for Pb+Pb collisions at 40$A$ GeV using forward calorimeters (VCal and RCal) for event plane estimation.

   nucl-exNPA(2019)·16 citations
3. 03*

   Partial correlation analysis in ultra-relativistic nuclear collisions

   Wojciech Broniowski🇵🇱 · Adam Olszewski🇵🇱

   We show that the method of partial covariance is a very efficient way to introduce constraints (such as the centrality selection) in data analysis in ultra-relativistic nuclear collisions. The technique eliminates spurious event-by-event fluctuations of physical quantities due to fluctuations of control variables. Moreover, in the commonly used superposition approach to particle production the method can be used to impose constraints on the initial sources rather than on the finally produced particles, thus separating out the trivial fluctuations from statistical hadronization or emission from sources and focusing strictly on the initial-state physics. As illustration, we use simulated data from hydrodynamics started on the wounded-quark event-by-event initial conditions, followed with statistical hadronization, to show the practicality of the approach in analyzing the forward-backward multiplicity fluctuations. We mention generalizations to the case with several constraints and other observables, such as the transverse momentum or eccentricity correlations.

   ↳ nucl-thnucl-ex0 citations
4. 04*

   High-energy neutrino-nucleus interactions

   S. Kumano🇯🇵

   High-energy neutrino-nucleus interactions are discussed by considering neutrino-oscillation experiments and ultra-high-energy cosmic neutrino interactions. The largest systematic error for the current neutrino oscillation measurements comes from the neutrino-nucleus interaction part, and its accurate understanding is essential for high-precision neutrino physics, namely for studying CP violation in the lepton sector. Depending on neutrino beam energies, quasi-elastic, resonance, Regge, or/and deep inelastic scattering (DIS) processes contribute to the neutrino cross section. It is desirable to have a code to calculate the neutrino-nucleus cross section in any kinematical range by combining various theoretical descriptions. On the other hand, the IceCube collaboration started obtaining cross section data up to the $10^{15}$ eV range, so that it became necessary to understand ultra-high-energy neutrino interactions beyond the artificial lepton-accelerator energy range. For future precise neutrino physics including the CP measurement, it is also necessary to understand accurate nuclear corrections. The current status is explained for nuclear corrections in DIS structure functions. The possibility is also discussed to find gravitational sources within nucleons and nuclei, namely matrix elements of quark-gluon energy-momentum tensor. They could be probed by neutrino interactions without replying on direct ultra-weak "gravitational interactions" with high-intensity neutrino beams, possibly at a future neutrino factory, by using techniques of hadron tomography.

   ↳ hep-phhep-exnucl-exnucl-thEPJ Web Conf.(2019)·2 citations
5. 05*

   Study of ${\rm Y}$ production in $p$Pb collisions at $\sqrt{s_{NN}}=8.16$ TeV

   LHCb collaboration: R. Aaij🇳🇱 · C. Abellán Beteta🇨🇭 · B. Adeva🇪🇸 · M. Adinolfi🇬🇧 · C.A. Aidala🇺🇸 · Z. Ajaltouni🇫🇷 · S. Akar🇺🇸 · P. Albicocco🇮🇹 · J. Albrecht🇩🇪 · F. Alessio🇨🇭 · M. Alexander🇬🇧 · A. Alfonso Albero🇪🇸 and 832 other authors

   The production of ${\rm Y}(nS)$ mesons ($n=1,2,3$) in $p$Pb and Pb$p$ collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{NN}}=8.16$ TeV is measured by the LHCb experiment, using a data sample corresponding to an integrated luminosity of 31.8 nb${}^{-1}$. The ${\rm Y}(nS)$ mesons are reconstructed through their decays into two opposite-sign muons. The measurements comprise the differential production cross-sections of the ${\rm Y}(1S)$ and ${\rm Y}(2S)$ states, their forward-to-backward ratios and nuclear modification factors, performed as a function of the transverse momentum \pt and rapidity in the nucleon-nucleon centre-of-mass frame $y^{\ast }$ of the ${\rm Y}(nS)$ states, in the kinematic range $p_{\mathrm{T}}<25$ GeV/$c$ and $1.5<y^{\ast }<4.0$ ($-5.0<y^{\ast }<-2.5$) for $p$Pb (Pb$p$) collisions. In addition, production cross-sections for ${\rm Y}(3S)$ are measured integrated over phase space and the production ratios between all three ${\rm Y}(nS)$ states are determined. The measurements are compared to theoretical predictions and suppressions for quarkonium in $p$Pb collisions are observed.

   ↳ hep-exnucl-exJHEP(2018)·91 citations
6. 06*

   Monte Carlo Simulations of Trapped Ultracold Neutrons in the UCN{\tau} Experiment

   Nathan Callahan · Chen-Yu Liu · Francisco Gonzalez · Evan Adamek · James David Bowman · Leah Broussard · S.M. Clayton · S. Currie · C. Cude-Woods · E.B. Dees · X. Ding · E.M. Egnel and 28 other authors

   In the UCN{\tau} experiment, ultracold neutrons (UCN) are confined by magnetic fields and the Earth's gravitational field. Field-trapping mitigates the problem of UCN loss on material surfaces, which caused the largest correction in prior neutron experiments using material bottles. However, the neutron dynamics in field traps differ qualitatively from those in material bottles. In the latter case, neutrons bounce off material surfaces with significant diffusivity and the population quickly reaches a static spatial distribution with a density gradient induced by the gravitational potential. In contrast, the field-confined UCN -- whose dynamics can be described by Hamiltonian mechanics -- do not exhibit the stochastic behaviors typical of an ideal gas model as observed in material bottles. In this report, we will describe our efforts to simulate UCN trapping in the UCN{\tau} magneto-gravitational trap. We compare the simulation output to the experimental results to determine the parameters of the neutron detector and the input neutron distribution. The tuned model is then used to understand the phase space evolution of neutrons observed in the UCN{\tau} experiment. We will discuss the implications of chaotic dynamics on controlling the systematic effects, such as spectral cleaning and microphonic heating, for a successful UCN lifetime experiment to reach a 0.01% level of precision.

   ↳ physics.ins-detnucl-exPRC(2019)·9 citations
7. 07*

   A novel experimental setup for rare events selection and its potential application to super heavy elements search

   Z. Majka🇵🇱 · R. Planeta🇵🇱 · Z. Sosin🇵🇱 · A. Wieloch🇵🇱 · K. Zelga · M. Adamczyk🇵🇱 · K. Pelczar🇮🇹 · M. Barbui🇺🇸 · S. Wuenschel🇺🇸 · K. Hagel🇺🇸 · X. Cao🇺🇸 · E-J. Kim and 5 other authors

   The paper presents a novel instrumentation for rare events selection which was tested in our research of short lived super heavy elements production and detection. The instrumentation includes an active catcher multi elements system and dedicated electronics. The active catcher located in the forward hemisphere is composed of 63 scintillator detection modules. Reaction products of damped collisions between heavy ion projectiles and heavy target nuclei are implanted in the fast plastic scintillators of the active catcher modules. The acquisition system trigger delivered by logical branch of the electronics allows to record the reaction products which decay via the alpha particle emissions or spontaneous fission which take place between beam bursts. One microsecond wave form signal from FADCs contains information on heavy implanted nucleus as well as its decays.

   ↳ physics.ins-detnucl-exActa Phys.Polon.B(2018)·6 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.