Mon·Jul 18, 2022Monday·July 18, 2022

1. 01*

   Charm production and hadronization in pp and p-Pb collisions at the LHC with ALICE

   Annalena Sophie Kalteyer (for the ALICE Collaboration)🇩🇪

   Studies of open-charm hadron production in pp and \pPb collisions are performed by the ALICE Collaboration at the LHC to investigate charm-quark hadronization mechanisms. Recent measurements of charm meson (${\mathrm{D}}^0$, ${\mathrm{D}}^{+}$, ${\mathrm{D}}_{\mathrm{s}}^{+}$, and ${\mathrm{D}}^{\ast +}$) and baryon (${\Lambda }_{\mathrm{c}}^{+}$, ${\Xi }_{\mathrm{c}}^{0,+}$, ${\Sigma }_{\mathrm{c}}^{0,++}$, and ${\Omega }_{\mathrm{c}}^0$) production in pp collisions at $\sqrt{s}$ = 5.02 TeV and $\sqrt{s}$ = 13 TeV allow the determination of the charm cross section and the fragmentation fractions at $\sqrt{s}$ = 5.02 TeV with unprecedented precision. The measurements show that the fragmentation fractions significantly differ from the ones measured in ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ and \ep collisions. This highlights possible differences in the hadronization process between electron induced collisions and pp collisions at the LHC. \\ Furthermore, the first measurement of the baryon-to-meson yield ratio ${\Lambda }_{\mathrm{c}}^{+}/{\mathrm{D}}^0$, down to $p_{\mathrm{T}}=0$ in pp and \pPb collisions will be discussed. In p--Pb collisions a modification of the hadronization mechanisms could be present due to cold nuclear matter effects and collective phenomena. A systematic comparison between data and model calculations will help to understand charm quark hadronization in pp and p--Pb collisions.

   nucl-exhep-ex0 citations
2. 02*

   Final Result of the MAJORANA DEMONSTRATOR's Search for Neutrinoless Double-$\beta$ Decay in ${}^{76}$Ge

   I.J. Arnquist🇺🇸 · F.T. Avignone III🇺🇸 · A.S. Barabash🇷🇺 · C.J. Barton🇺🇸 · P.J. Barton🇺🇸 · K.H. Bhimani🇺🇸 · E. Blalock🇺🇸 · B. Bos🇺🇸 · M. Busch🇺🇸 · M. Buuck🇺🇸 · T.S. Caldwell🇺🇸 · Y-D. Chan🇺🇸 and 48 other authors

   The MAJORANA DEMONSTRATOR searched for neutrinoless double-$\beta$ decay ($0\nu \beta \beta$) of ${}^{76}$Ge using modular arrays of high-purity Ge detectors operated in vacuum cryostats in a low-background shield. The arrays operated with up to 40.4 kg of detectors (27.2 kg enriched to $\sim$88\% in ${}^{76}$Ge). From these measurements, the DEMONSTRATOR has accumulated 64.5 kg yr of enriched active exposure. With a world-leading energy resolution of 2.52 keV FWHM at the 2039 keV $Q_{\beta \beta }$ (0.12\%), we set a half-life limit of $0\nu \beta \beta$ in ${}^{76}$Ge at $T_{1/2}>8.3\times 10^{25}$ yr (90\% C.L.). This provides a range of upper limits on $m_{\beta \beta }$ of $(113-269)$ meV (90\% C.L.), depending on the choice of nuclear matrix elements.

   nucl-exhep-exphysics.ins-detPRL(2023)·177 citations
3. 03*

   Systematic Trends of 0${}_2^{+}$, 1${}_1^{-}$, 3${}_1^{-}$ and 2${}_1^{+}$ Excited States in Even-Even Nuclei

   B. Pritychenko🇺🇸 · B. Singh🇮🇳 · M. Verpelli🇦🇹

   The spin and parity ($J^{\pi }$) assignments in even-even nuclei were reviewed across the nuclear chart using the Evaluated Nuclear Structure Data File (ENSDF). The prevalence of 2${}_1^{+}$ first or lowest excited states is confirmed. The properties of 0${}_2^{+}$, 1${}_1^{-}$, and 3${}_1^{-}$ lowest excited states were reexamined using the ENSDF data evaluation procedures. The $J^{\pi }$ systematic trends and correlations between level quantum numbers and nuclear physics phenomena are discussed.

   nucl-exnucl-thNPA(2022)·8 citations
4. 04*

   Low energy structures in nuclear reactions with 4n in the final state

   Rimantas Lazauskas🇫🇷 · Emiko Hiyama🇯🇵 · Jaume Carbonell🇫🇷

   We present a reaction model to describe the fast removal of the $\alpha$-particle core in ${}^8$He nucleus with eventual emission of four neutrons. The obtained four neutron energy distributions allows to explain the sharp low energy peak observed by studying the missing mass spectra of four neutrons in [Nature Vol. 606, p. 678], as a consequence of dineutron-dineutron correlations.

   ↳ nucl-thnucl-exPRL(2023)·44 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.