Thu·Jan 7, 2021Thursday·January 7, 2021

1. 01*

   Position uncertainties of AGATA pulse-shape analysis estimated via the boostrapping method

   M. Siciliano🇫🇷 · J. Ljungvall🇫🇷 · A. Goasduff🇮🇹 · A. Lopez-Martens🇫🇷 · M. Zielińska🇫🇷

   The unprecedented capabilities of state-of-the-art segmented germanium-detector arrays, such as AGATA and GRETA, derive from the possibility of performing pulse-shape analysis. The comparison of the net- and transient-charge signals with databases via grid-search methods allows the identification of the $\gamma$-ray interaction points within the segment volume. Their precise determination is crucial for the subsequent reconstruction of the $\gamma$-ray paths within the array via tracking algorithms, and hence the performance of the spectrometer. In this paper the position uncertainty of the deduced interaction point is investigated using the bootstrapping technique applied to ${}^{60}$Co radioactive-source data. General features of the extracted position uncertainty are discussed as well as its dependence on various quantities, e.g. the deposited energy, the number of firing segments and the segment geometry.

   nucl-exEPJA(2021)·5 citations
2. 02*

   Probing nuclear forces beyond the nuclear drip line: The cases of ${}^{16}$F and ${}^{15}$F

   V. Girard-Alcindor · I. Stefan · F. de Oliveira Santos · O. Sorlin · D. Ackermann · P. Adsley · J.C. Angelique · M. Assie · M. Assuncao · D. Beaumel · E. Berthoumieux · R. Borcea and 44 other authors

   The unbound proton-rich nuclei ${}^{16}$F and ${}^{15}$F are investigated experimentally and theoretically. Several experiments using the resonant elastic scattering method were performed at GANIL with radioactive beams to determine the properties of the low lying states of these nuclei. Strong asymmetry between ${}^{16}$F-${}^{16}$N and ${}^{15}$F-${}^{15}$C mirror nuclei is observed. The strength of the $nucleon-nucleon$ effective interaction involving the loosely bound proton in the $s_{1/2}$ orbit is significantly modified with respect to their mirror nuclei ${}^{16}$N and ${}^{15}$C. The reduction of the effective interaction is estimated by calculating the interaction energies with a schematic zero-range force. It is found that, after correcting for the effects due to changes in the radial distribution of the single-particle wave functions, the mirror symmetry of the $n-p$ interaction is preserved between ${}^{16}$F and ${}^{16}$N, while a difference of 63\% is measured between the $p-p$ versus $n-n$ interactions in the second excited state of ${}^{15}$F and ${}^{15}$C nuclei. Several explanations are proposed.

   nucl-exEPJA(2021)·5 citations
3. 03*

   Time-lens Photon Doppler Velocimetry (TL-PDV)

   Pinghan Chu🇺🇸 · Velat Kilic🇺🇸 · Mark A. Foster🇺🇸 · Zhehui Wang🇺🇸

   We describe a time lens to expand the dynamic range of photon Doppler velocimetry (PDV) systems. The principle and preliminary design of a time-lens PDV (TL-PDV) are explained and shown to be feasible through simulations. In a PDV system, an interferometer is used for measuring frequency shifts due to the Doppler effect from the target motion. However, the sampling rate of the electronics could limit the velocity range of a PDV system. A four-wave-mixing (FWM) time lens applies a quadratic temporal phase to an optical signal within a nonlinear FWM medium (such as an integrated photonic waveguide or highly nonlinear optical fiber). By spectrally isolating the mixing product, termed the idler, and with appropriate lengths of dispersion prior and after to this FWM time lens, a temporally magnified version of the input signal is generated. Therefore, the frequency shifts of PDV can be "slowed down" with the magnification factor $M$ of the time lens. $M=1$ corresponds to a regular PDV without a TL. $M=10$ has been shown to be feasible for a TL-PDV. Use of this effect for PDV can expand the velocity measurement range and allow the use of lower bandwidth electronics. TL-PDV will open up new avenues for various dynamic materials experiments.

   ↳ physics.opticsnucl-exRev.Sci.Instrum.(2021)·0 citations
4. 04*

   Efficiency corrections for factorial moments and cumulants of overlapping sets of particles

   Volodymyr Vovchenko🇺🇸 · Volker Koch🇺🇸

   In this note we discuss subtleties associated with the efficiency corrections for measurements of off-diagonal cumulants and factorial moments for a situation when one deals with overlapping sets of particles, such as correlations between numbers of protons and positively charged particles. In particular, we discuss the situation commonly encountered in heavy-ion experiments, where first all charges are reconstructed and then protons are selected from these charges by an additional particle identification procedure. We present the efficiency correction formulas for the case when the detection efficiencies follow a binomial distribution.

   ↳ nucl-thhep-phnucl-exNPA(2021)·5 citations
5. 05*

   $W$-boson production in polarized proton-proton collisions at RHIC through next-to-next-to-leading order in perturbative QCD

   Radja Boughezal🇺🇸 · Hai Tao Li🇺🇸 · Frank Petriello🇺🇸

   We perform a study of $W$-boson production in polarized proton-proton collisions through next-to-next-to-leading order (NNLO) in perturbative QCD. This calculation is required to extend the extraction of polarized parton distribution functions to NNLO accuracy. We present differential distributions at $\sqrt{s}=510$ GeV, relevant for comparison to measurements from the Relativistic Heavy Ion Collider (RHIC). The NNLO QCD corrections significantly reduce the scale dependence of the cross section. We compare the longitudinal single-spin asymmetries as a function of lepton pseudorapidity to RHIC data. The asymmetries exhibit excellent stability under perturbative QCD corrections.

   ↳ hep-phhep-exnucl-exPLB(2021)·15 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.