Tue·Mar 30, 2021Tuesday·March 30, 2021

1. 01*

   Quenching effects in the cumulative jet spectrum

   Adam Takacs🇳🇴 · Konrad Tywoniuk🇳🇴

   The steeply falling jet spectrum induces bias on the medium modifications of jet observables in heavy-ion collisions. To explore this bias, we develop a novel analytic framework to study the quenched jet spectrum, and its cumulative. We include many energy-loss-related effects, such as soft and hard medium induced emissions, broadening, elastic scattering, jet fragmentation, cone size, coherence effects, etc. We show that, different jet spectrum-based observables are connected, e.g., the nuclear modification, spectrum shift, and the quantile procedure. We present the first predictions for the nuclear modification factor and the quantile procedure with cone size dependence. As an example, we compare dijet and boson+jet events to unfold the spectrum bias effects. We improve quark-, and gluon-jet classification using arguments based on the cumulative. Besides pointing out its flexibility, we apply our framework with other energy loss models such as the hybrid weak-, strong-coupling.

   ↳ hep-phhep-exhep-thnucl-ex+1JHEP(2021)·36 citations
2. 02*

   Characterization of inverted coaxial ${}^{76}$Ge detectors in GERDA for future double-$\beta$ decay experiments

   GERDA collaboration: M. Agostini🇬🇧 · G. R. Araujo🇨🇭 · A. M. Bakalyarov🇷🇺 · M. Balata🇮🇹 · I. Barabanov🇷🇺 · L. Baudis🇨🇭 · C. Bauer🇩🇪 · E. Bellotti🇮🇹 · S. Belogurov🇷🇺 · A. Bettini🇮🇹 · L. Bezrukov🇷🇺 · V. Biancacci🇮🇹 and 98 other authors

   Neutrinoless double-$\beta$ decay of ${}^{76}$Ge is searched for with germanium detectors where source and detector of the decay are identical. For the success of future experiments it is important to increase the mass of the detectors. We report here on the characterization and testing of five prototype detectors manufactured in inverted coaxial (IC) geometry from material enriched to 88% in ${}^{76}$Ge. IC detectors combine the large mass of the traditional semi-coaxial Ge detectors with the superior resolution and pulse shape discrimination power of point contact detectors which exhibited so far much lower mass. Their performance has been found to be satisfactory both when operated in vacuum cryostat and bare in liquid argon within the GERDA setup. The measured resolutions at the Q-value for double-$\beta$ decay of ${}^{76}$Ge (Q${}_{\beta \beta }$ = 2039 keV) are about 2.1 keV full width at half maximum in vacuum cryostat. After 18 months of operation within the ultra-low background environment of the GERmanium Detector Array (GERDA) experiment and an accumulated exposure of 8.5 kg$\cdot$yr, the background index after analysis cuts is measured to be $4.9_{-3.4}^{+7.3}\times 10^{-4}$ counts /(keV$\cdot$kg$\cdot$yr) around Q${}_{\beta \beta }$. This work confirms the feasibility of IC detectors for the next-generation experiment LEGEND.

   ↳ physics.ins-detnucl-exEPJC(2021)·23 citations
3. 03*

   Higher order cumulants of transverse momentum and harmonic flow in relativistic heavy ion collisions

   Piotr Bozek🇵🇱 · Rupam Samanta🇵🇱

   Higher order symmetric cumulants of global collective observables in heavy ion collisions are studied. The symmetric cumulants can be straightforwardly constructed for scalar observables: the average transverse momentum, the multiplicity, and the squares of harmonic flow vectors. Third and fourth order cumulants are calculated in the hydrodynamic model. A linear predictor of the average transverse momentum and harmonic flow coefficients in a collision is used to predict the value of the cumulants from the moments of the initial distribution. The symmetric cumulants divided by the averages (or the standard deviations) of the considered observables can be used as a fine tool to study correlations present in the initial state of the collision.

   ↳ nucl-thnucl-exPRC(2021)·17 citations
4. 04*

   Nuclear Fermi Momenta of ${}^2$H, ${}^{27}$Al and ${}^{56}$Fe from an Analysis of CLAS data

   Hui Liu🇨🇳 · Na-Na Ma🇨🇳 · Rong Wang🇨🇳

   Nuclear Fermi momentum is a basic property of a nucleus where many nucleons dwell. However, in experiments only the nuclear Fermi momenta of just a few nuclei are measured using quasielastic electron scattering on the nuclear targets so far. Particularly, we still do not know experimentally the Fermi momentum of the lightest nucleon composite -- the deuteron. In this paper, we apply both gaussian distribution and Cauchy distribution to describe the quasielastic peak in the cross section of electron-nucleus scattering. The dip of the cross-section ratio at about $x_{\mathrm{B}}=1$ is explained with the nuclear Fermi momentum. By performing the least-square fits to the published CLAS data in the narrow kinematic region of quasielastic scattering, we obtain the nuclear Fermi momenta of ${}^2$H, ${}^{27}$Al and ${}^{56}$Fe, which are $116\pm 7$ MeV/c, $232\pm 27$ MeV/c, and $244\pm 28$ MeV/c respectively. The extracted nuclear Fermi momenta are compared to the simple calculations based on Fermi gas model, and the consistencies are found.

   ↳ nucl-thnucl-exNPA(2022)·1 citation

* 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.