Tue·May 10, 2022Tuesday·May 10, 2022

1. 01*

   Measurement of the prompt $D^0$ nuclear modification factor in $p$Pb collisions at $\sqrt{s_{\mathrm{NN}}}=8.16$ TeV

   LHCb collaboration

   The production of prompt $D^0$ mesons in proton-lead collisions in the forward and backward configurations at a center-of-mass energy per nucleon pair of $\sqrt{s_{\mathrm{NN}}}=8.16\mathrm{TeV}$ is measured by the LHCb experiment. The nuclear modification factor of prompt $D^0$ mesons is determined as a function of the transverse momentum $p_{\mathrm{T}}$, and rapidity in the nucleon-nucleon center-of-mass frame $y^{\ast }$. In the forward rapidity region, significantly suppressed production with respect to $pp$ collisions is measured, which provides significant constraints of nuclear parton distributions and hadron production down to the very low Bjorken-$x$ region of $\sim 10^{-5}$. In the backward rapidity region, a suppression with a significance of 2.0 - 3.8 standard deviations compared to nPDF expectations is found in the kinematic region of $p_{\mathrm{T}}>6\mathrm{GeV}/c$ and $-3.25<y^{\ast }<-2.5$, corresponding to $x\sim 0.01$.

   nucl-exhep-exPRL(2023)·42 citations
2. 02*

   First results of the nuGeN experiment on coherent elastic neutrino-nucleus scattering

   I. Alekseev🇷🇺 · K. Balej🇨🇿 · V. Belov🇷🇺 · S. Evseev🇷🇺 · D. Filosofov🇷🇺 · M. Fomina🇷🇺 · Z. Hons🇷🇺 · D. Karaivanov🇷🇺 · S. Kazartsev🇷🇺 · J. Khushvaktov🇷🇺 · A. Kuznetsov🇷🇺 · A. Lubashevskiy🇷🇺 and 12 other authors

   The nuGeN experiment is aimed to investigate neutrino properties using antineutrinos from the reactor of the Kalinin Nuclear Power Plant. The experimental setup is located at about 11 meters from the center of the 3.1 GWth reactor core. Scattering of the antineutrinos from the reactor is detected with low energy threshold high purity germanium detector. Passive and active shieldings are used to suppress all kinds of backgrounds coming from surrounding materials and cosmic radiation. The description of the experimental setup together with the first results is presented. The data taken in regimes with reactor ON (94.50 days) and reactor OFF (47.09 days) have been compared. No significant difference between spectra of two data sets is observed, i.e. no positive signals for coherent elastic neutrino-nucleus scattering are detected. Under Standard Model assumptions about coherent neutrino scattering an upper limit on a quenching parameter k < 0.26 (90 \% C.L.) in germanium has been set.

   nucl-exhep-exPRD(2022)·72 citations
3. 03*

   UPC contribution to forward rapidity gap distribution in pPb collisions at the LHC

   V. Guzey (St. Petersburg, INP)🇷🇺 · M. Strikman (Penn State U.)🇺🇸 · M. Zhalov (St. Petersburg, INP)🇷🇺

   In this Letter, we consider strong and electromagnetic (ultraperipheral) mechanisms in proton-nucleus coherent diffraction at the CERN Large Hadron Collider. We explicitly demonstrate the dominance of the latter and explain the CMS data on the forward rapidity gap distribution in $pPb$ collisions at $\sqrt{s_{NN}}=8.16$ TeV. In particular, we provide simple estimates, which give a good, semi-quantitative description of both magnitude and shape of the $\Delta {\eta }^F$ distribution in the Pomeron-proton topology. We also make predictions for the proton-oxygen run.

   ↳ hep-phhep-exnucl-exPRC(2022)·2 citations
4. 04*

   Azimuthal-sensitive three-dimensional HBT radius in Au-Au collisions at $E_{beam}=1.23$$A$ GeV by the IQMD model

   Ling-Meng Fang🇨🇳 · Yu-Gang Ma🇨🇳 · Song Zhang🇨🇳

   We used an Isospin dependent Quantum Molecular Dynamics (IQMD) model to simulate Au + Au collisions at beam energy $E_{beam}$ = 1.23$A$ GeV, which corresponds to center of mass energy $\sqrt{s_{NN}}=2.4$ GeV. Firstly, we obtained reasonable rapidity and transverse mass spectra of ${\pi }^{-}$ and ${\pi }^{+}$ as well as "apparent" temperature parameters in comparison with the HADES data. Then by calculating three-dimensional Hanbury Brown and Twiss (HBT) radius of same charged pion-pairs, we obtained the square difference of outward radius and sideward radius, i.e. $R_{out}^2-R_{side}^2$, as well as the freeze-out volume ($V_{fo}$), which were basically consistent with the trend of HADES experimental results. The azimuthal dependence of the HBT radii was also calculated by a matrix method, and corrected by the rotation matrix. In addition, the eccentricities of the $xy$- and $zy$- planes of pion-pair emissions were also extracted for different pair transverse momentum and collision centrality, which show that the $xy$-eccentricity increases with pair transverse momentum as well as centrality but not for $zy$-eccentricity, indicating a more asymmetric transverse emission of particle-pairs with higher transverse momentum in off-central collisions.

   ↳ nucl-thnucl-exEPJA(2022)·8 citations
5. 05*

   Double-Weak Decays of ${}^{124}$Xe and ${}^{136}$Xe in the XENON1T and XENONnT Experiments

   E. Aprile🇺🇸 · K. Abe🇯🇵 · F. Agostini🇮🇹 · S. Ahmed Maouloud🇫🇷 · M. Alfonsi🇩🇪 · L. Althueser🇩🇪 · B. Andrieu🇫🇷 · E. Angelino🇮🇹 · J. R. Angevaare🇳🇱 · V. C. Antochi🇸🇪 · D. Antón Martin🇺🇸 · F. Arneodo🇦🇪 and 148 other authors

   We present results on the search for double-electron capture ($2\nu \text{ECEC}$) of ${}^{124}$Xe and neutrinoless double-$\beta$ decay ($0\nu \beta \beta$) of ${}^{136}$Xe in XENON1T. We consider captures from the K- up to the N-shell in the $2\nu \text{ECEC}$ signal model and measure a total half-life of $T_{1/2}^{2\nu \text{ECEC}}=(1.1\pm 0.2_{\text{stat}}\pm 0.1_{\text{sys}})\times 10^{22}\text{yr}$ with a $0.87\text{kg}\times \text{yr}$ isotope exposure. The statistical significance of the signal is $7.0\sigma$. We use XENON1T data with $36.16\text{kg}\times \text{yr}$ of ${}^{136}$Xe exposure to search for $0\nu \beta \beta$. We find no evidence of a signal and set a lower limit on the half-life of $T_{1/2}^{0\nu \beta \beta }>1.2\times 10^{24}\text{yr}\text{at}90\%\text{CL}$. This is the best result from a dark matter detector without an enriched target to date. We also report projections on the sensitivity of XENONnT to $0\nu \beta \beta$. Assuming a $275\text{kg}\times \text{yr}$ ${}^{136}$Xe exposure, the expected sensitivity is $T_{1/2}^{0\nu \beta \beta }>2.1\times 10^{25}\text{yr}\text{at}90\%\text{CL}$, corresponding to an effective Majorana mass range of $⟨m_{\beta \beta }⟩<(0.19-0.59){\text{eV/c}}^2$.

   ↳ hep-exnucl-exPRC(2022)·80 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.