Thu·Apr 22, 2021Thursday·April 22, 2021

1. 01*

   Semileptonic $B_c\to {\eta }_c,J/\psi$ transitions

   Zhao-Qian Yao🇨🇳 · Daniele Binosi🇮🇹 · Zhu-Fang Cui🇨🇳 · Craig D. Roberts🇨🇳

   Using a systematic, symmetry-preserving continuum approach to the Standard Model strong-interaction bound-state problem, we deliver parameter-free predictions for all semileptonic $B_c\to {\eta }_c,J/\psi$ transition form factors on the complete domains of empirically accessible momentum transfers. Working with branching fractions calculated therefrom, the following values of the ratios for $\tau$ over $\mu$ final states are obtained: $R_{{\eta }_c}=0.313(22)$ and $R_{J/\psi }=0.242(47)$. Combined with other recent results, our analysis confirms a $2\sigma$ discrepancy between the Standard Model prediction for $R_{J/\psi }$ and the single available experimental result.

   ↳ hep-phhep-exhep-latnucl-ex+1PLB(2021)·25 citations
2. 02*

   Investigations on mixed harmonic cumulants in heavy-ion collisions at the LHC

   Ming Li🇨🇳 · You Zhou🇩🇰 · Wenbin Zhao🇨🇳 · Baochi Fu🇨🇳 · Yawen Mou🇨🇳 · Huichao Song🇨🇳

   A series of new flow observables mixed harmonic multi-particle cumulants (MHC), which allow for the first time to quantify the correlations strength between different order of flow coefficients with various moments, was investigated using hydrodynamic model. These new observables are constructed based on multi-particle cumulants, and thus by design will be less sensitive to the non-flow contaminations. In addition to the previous study of correlation involving two flow coefficients with their second moments, both correlations of three flow coefficients and the correlations of higher order moments of $v_2$ and $v_3$ are systematically investigated using iEBE-VISHNU hybrid model with two different initial conditions, AMPT and TRENTo, respectively. These systematic studies using hydrodynamic models will significantly improve the understanding on the correlations between different orders (and moments) of flow coefficients. The hydrodynamic predictions shown in this paper and the future comparisons to experimental measurements will provide more constraints on theoretical models and extract more information about the transport properties of the quark-gluon plasma created in heavy-ion collisions.

   ↳ nucl-thhep-phnucl-exPRC(2021)·12 citations
3. 03*

   The nylon balloon for xenon loaded liquid scintillator in KamLAND-Zen 800 neutrinoless double-beta decay search experiment

   KamLAND-Zen collaboration : Y. Gando🇯🇵 · A. Gando🇯🇵 · T. Hachiya🇯🇵 · S. Hayashida🇯🇵 · K. Hosokawa🇯🇵 · H. Ikeda🇯🇵 · T. Mitsui🇯🇵 · T. Nakada🇨🇭 · S. Obara🇯🇵 · H. Ozaki🇯🇵 · J. Shirai🇯🇵 · K. Ueshima🇯🇵 and 60 other authors

   The KamLAND-Zen 800 experiment is searching for the neutrinoless double-beta decay of ${}^{136}$Xe by using ${}^{136}$Xe-loaded liquid scintillator. The liquid scintillator is enclosed inside a balloon made of thin, transparent, low-radioactivity film that we call Inner Balloon (IB). The IB, apart from guaranteeing the liquid containment, also allows to minimize the background from cosmogenic muon-spallation products and ${}^8$B solar neutrinos. Indeed these events could contribute to the total counts in the region of interest around the Q-value of the double-beta decay of ${}^{136}$Xe. In this paper, we present an overview of the IB and describe the various steps of its commissioning minimizing the radioactive contaminations, from the material selection, to the fabrication of the balloon and its installation inside the KamLAND detector. Finally, we show the impact of the IB on the KamLAND background as measured by the KamLAND detector itself.

   ↳ physics.ins-dethep-exnucl-exJINST·34 citations
4. 04*

   The SuSA model for neutrino oscillation experiments: from quasielastic scattering to the resonance region

   Maria B. Barbaro🇮🇹 · Arturo De Pace🇮🇹 · Luisa Fiume🇮🇹

   High precision studies of Beyond-Standard-Model physics through accelerator-based neutrino oscillation experiments require a very accurate description of neutrino-nucleus cross sections in a broad energy region, going from quasielastic scattering up to deep inelastic scattering. In this work we focus on the following processes: quasielastic scattering, two-particle-two-hole excitations, and the excitation of the first (Delta) and second (Roper) resonances of the nucleon. The nuclear model is fully relativistic and includes both one- and two-body currents. We compare our results with recent T2K and MicroBooNE data on carbon and argon targets, and present predictions for DUNE kinematics.

   ↳ hep-phhep-exnucl-exnucl-thUniverse(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.