Wed·Oct 20, 2021Wednesday·October 20, 2021

1. 01*

   Measurement of cold nuclear matter effects for inclusive $J/\psi$ in $p$+Au collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}$ = 200 GeV

   STAR Collaboration: M. S. Abdallah🇪🇬 · B. E. Aboona🇺🇸 · J. Adam🇺🇸 · L. Adamczyk🇵🇱 · J. R. Adams🇺🇸 · J. K. Adkins🇺🇸 · G. Agakishiev🇷🇺 · I. Aggarwal🇮🇳 · M. M. Aggarwal🇮🇳 · Z. Ahammed🇮🇳 · I. Alekseev🇷🇺 · D. M. Anderson🇺🇸 and 385 other authors

   Measurement by the STAR experiment at RHIC of the cold nuclear matter (CNM) effects experienced by inclusive $J/\psi$ at mid-rapidity in 0-100\% $p$+Au collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}$ = 200 GeV is presented. Such effects are quantified utilizing the nuclear modification factor, $R_{p\mathrm{Au}}$, obtained by taking a ratio of $J/\psi$ yield in $p$+Au collisions to that in $p$+$p$ collisions scaled by the number of binary nucleon-nucleon collisions. The differential $J/\psi$ yield in both $p$+$p$ and $p$+Au collisions is measured through the dimuon decay channel, taking advantage of the trigger capability provided by the Muon Telescope Detector in the RHIC 2015 run. Consequently, the $J/\psi$ $R_{p\mathrm{Au}}$ is derived within the transverse momentum ($p_{\mathrm{T}}$) range of 0 to 10 GeV/$c$. A suppression of approximately 30% is observed for $p_{\mathrm{T}}<2$ GeV/$c$, while $J/\psi$ $R_{p\mathrm{Au}}$ becomes compatible with unity for $p_{\mathrm{T}}$ greater than 3 GeV/$c$, indicating the $J/\psi$ yield is minimally affected by the CNM effects at high $p_{\mathrm{T}}$. Comparison to a similar measurement from 0-20% central Au+Au collisions reveals that the observed strong $J/\psi$ suppression above 3 Gev/$c$ is mostly due to the hot medium effects, providing strong evidence for the formation of the quark-gluon plasma in these collisions. Several model calculations show qualitative agreement with the measured $J/\psi$ $R_{p\mathrm{Au}}$, while their agreement with the $J/\psi$ yields in $p$+$p$ and $p$+Au collisions is worse.

   nucl-exPLB(2022)·21 citations
2. 02*

   Measurement of Intermittency for Charged Particles in Au + Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 7.7-200 GeV from STAR

   Jin Wu (for the STAR Collaboration)🇨🇳

   Local density fluctuations near the QCD critical point can be probed by intermittency analysis of scaled factorial moments in relativistic heavy-ion collisions. We report the first measurement of intermittency for charged particles in Au + Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 7.7-200 GeV from the STAR experiment at RHIC. We observe scaling behaviors in central Au + Au collisions, with the extracted scaling exponent decreasing from mid-central to the most central Au + Au collisions. Furthermore, the scaling exponent exhibits a non-monotonic energy dependence with a minimum around $\sqrt{s_{\mathrm{NN}}}$ = 20-30 GeV in central Au + Au collisions.

   nucl-exSciPost Phys.Proc.(2022)·8 citations
3. 03*

   Recent results of ${\text{D}}^0$ mesons azimuthal anisotropy using the CMS detector

   Cesar A. Bernardes (for the CMS Collaboration)🇧🇷

   In a relativistic heavy ion collision, heavy flavor (charm and bottom) quarks are mostly created via hard processes at the early stage of the collisions. We present the latest results of the azimuthal anisotropy coefficients $v_{\text{n}}$ for prompt and nonprompt ${\text{D}}^0$ mesons in PbPb, pPb, and pp collisions from the CMS experiment. The studies are about collectivity phenomena in smaller systems (pp and pPb collisions), searches for the effects of very strong electromagnetic fields created in the initial stages of ultrarelativistic PbPb collisions, and charm quark energy loss in the quark-gluon plasma.

   nucl-exhep-exPoS(2022)·0 citations
4. 04*

   Measurement of prompt ${\mathrm{D}}_{\mathrm{s}}^{+}$-meson production and azimuthal anisotropy in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

   ALICE Collaboration

   The production yield and angular anisotropy of prompt $D_s^{+}$ mesons were measured as a function of transverse momentum ($p_T$) in Pb-Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{NN}}=5.02$ TeV collected with the ALICE detector at the LHC. $D_s^{+}$ mesons and their charge conjugates were reconstructed at midrapidity ($|y|<0.5$) from their hadronic decay channel $D_s^{+}\to \varphi {\pi }^{+}$, with $\varphi \to K^{-}{K}^{+}$, in the $p_T$ intervals $2<p_T<50$ GeV/$c$ and $2<p_T<36$ GeV/$c$ for the 0-10% and 30-50% centrality intervals. For $p_T>10$ GeV/$c$, the measured $D_s^{+}$-meson nuclear modification factor $R_{AA}$ is consistent with the one of non-strange D mesons within uncertainties, while at lower $p_T$ a hint for a $D_s^{+}$-meson $R_{AA}$ larger than that of non-strange D mesons is seen. The enhanced production of $D_s^{+}$ relative to non-strange D mesons is also studied by comparing the $p_T$-dependent $D_s^{+}/D^0$ production yield ratios in Pb-Pb and in pp collisions. The ratio measured in Pb-Pb collisions is found to be on average higher than that in pp collisions in the interval $2<p_T<8$ GeV/$c$ with a significance of 2.3$\sigma$ and 2.4$\sigma$ for the 0-10% and 30-50% centrality intervals. The azimuthal anisotropy coefficient $v_2$ of prompt $D_s^{+}$ mesons was measured in Pb-Pb collisions in the 30-50% centrality interval and is found to be compatible with that of non-strange D mesons. The main features of the measured $R_{AA}$, $D_s^{+}/D^0$ ratio, and $v_2$ as a function of $p_T$ are described by theoretical calculations of charm-quark transport in a hydrodynamically expanding quark-gluon plasma including hadronisation via charm-quark recombination with light quarks from the medium. The $p_T$-integrated production yield of $D_s^{+}$ mesons is compatible with the prediction of the statistical hadronisation model.

   nucl-exhep-exPLB(2022)·92 citations
5. 05*

   ${\mathrm{K}}^{\ast }(892{)}^0$ and $\varphi (1020)$ production in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 8.16 TeV

   ALICE Collaboration

   The production of ${\mathrm{K}}^{\ast }(892{)}^0$ and $\varphi (1020)$ resonances has been measured in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 8.16 TeV using the ALICE detector. Resonances are reconstructed via their hadronic decay channels in the rapidity interval $-$0.5 $<$ $y$ $<$ 0 and the transverse momentum spectra are measured for various multiplicity classes up to $p_{\mathrm{T}}$ = 20 GeV/$c$ for ${\mathrm{K}}^{\ast }(892{)}^0$ and $p_{\mathrm{T}}$ = 16 GeV/$c$ for $\varphi (1020)$. The $p_{\mathrm{T}}$ -integrated yields and mean transverse momenta are reported and compared with previous results in pp, p-Pb and Pb-Pb collisions. The $x_{\mathrm{T}}$ scaling for ${\mathrm{K}}^{\ast }(892{)}^0$ and $\varphi (1020)$ resonance production is newly tested in p-Pb collisions and found to hold in the high-$p_{\mathrm{T}}$ region at Large Hadron Collider energies. The nuclear modification factors ($R_{\mathrm{pPb}}$) as a function of $p_{\mathrm{T}}$ for ${\mathrm{K}}^{\ast 0}$ and $\varphi$ at $\sqrt{s_{NN}}$ = 8.16 TeV are presented along with the new $R_{\mathrm{pPb}}$ measurements of ${\mathrm{K}}^{\ast 0}$, $\varphi$ , $\Xi$, and $\Omega$ at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV. At intermediate $p_{\mathrm{T}}$ (2-8 GeV/$c$), $R_{\mathrm{pPb}}$ of $\Xi$, $\Omega$ show a Cronin-like enhancement, while ${\mathrm{K}}^{\ast 0}$ and $\varphi$ show no or little nuclear modification. At high $p_{\mathrm{T}}$ ($>$ 8 GeV/$c$), the $R_{\mathrm{pPb}}$ values of all hadrons are consistent with unity within uncertainties. The $R_{\mathrm{pPb}}$ of ${\mathrm{K}}^{\ast }(892{)}^0$ and $\varphi (1020)$ at $\sqrt{s_{\mathrm{NN}}}$ = 8.16 and 5.02 TeV show no significant energy dependence.

   nucl-exhep-exPRC(2023)·27 citations
6. 06*

   Investigating charm production and fragmentation via azimuthal correlations of prompt D mesons with charged particles in pp collisions at $\sqrt{s}=13$ TeV

   ALICE Collaboration

   Angular correlations of heavy-flavour and charged particles in high-energy proton-proton collisions are sensitive to the production mechanisms of heavy quarks and to their fragmentation as well as hadronisation processes. The measurement of the azimuthal-correlation function of prompt D mesons with charged particles in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=13$ TeV with the ALICE detector is reported, considering D${}^0$, D${}^{+}$, and D${}^{\ast +}$ mesons in the transverse-momentum interval $3<p_{\mathrm{T}}<36$ GeV/$c$ at midrapidity ($|y|<0.5$), and charged particles with $p_{\mathrm{T}}>0.3$ GeV/$c$ and pseudorapidity $|\eta |<0.8$. This measurement has an improved precision and provides an extended transverse-momentum coverage compared to previous ALICE measurements at lower energies. The study is also performed as a function of the charged-particle multiplicity, showing no modifications of the correlation function with multiplicity within uncertainties. The properties and the transverse-momentum evolution of the near- and away-side correlation peaks are studied and compared with predictions from various Monte Carlo event generators. Among those considered, PYTHIA8 and POWHEG+PYTHIA8 provide the best description of the measured observables. The obtained results can provide guidance on tuning the generators.

   nucl-exhep-exEPJC(2022)·27 citations
7. 07*

   Comparative Study of Gamma to Neutron Ratios of various (alpha, neutron) Neutron Sources

   Sebastian Ritter

   The gamma to neutron ratio is measured via Pulse Shape Discrimination (PSD) of a Plutonium Beryllium (PuBe) source and of a rudimentary constructed Polonium Beryllium (PoBe) source using one organic liquid scintillator detector and digital signal processing. Furthermore, two organic liquid scintillator detectors and digital signal processing is used to conduct coincidence counting on the PoBe source. Measured data is compared to literature. The gamma to neutron source ratio was found to be 3.67 +/- 0.14 and 1.13 +/- 0.05 for the PuBe and for the PoBe source respectively. Both ratios are above literature values for the respective neutron sources. Coincidence counting analysis showed that the PoBe source emitted two or more coincident gamma-rays or neutrons with a confidence level of 91.77 % using a coincident window of 40ns and a detector source distance of 1 mm.

   nucl-exphysics.ins-det0 citations
8. 08*

   A direct-sampling RF receiver for MOLLER beam charge measurement

   Yuan Mei🇺🇸 · Shujie Li🇺🇸 · John Arrington🇺🇸 · Joseph Camilleri🇺🇸 · Aled Cuda · James Egelhoff · Yury Kolomensky🇺🇸 · Ernst Sichtermann🇺🇸

   We have developed and tested a direct-sampling RF receiver capable of measuring the amplitude of a 1497 MHz sinusoidal signal in 0.5 ms integration windows to within <10 ppm relative uncertainty. The receiver is intended for measuring signals from beam current monitoring cavities on the beamline of the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Laboratory. The signal strength, frequency, and integration window are consistent with the thus far unmet requirements of the upcoming MOLLER experiment to measure the beam charge for different helicity states.

   ↳ physics.ins-detnucl-exphysics.acc-phJINST(2022)·1 citation
9. 09*

   The MAGNEX magnetic spectrometer for double charge exchange reactions

   M. Cavallaro🇮🇹 · C. Agodi🇮🇹 · G. A. Brischetto🇮🇹 · S. Calabrese🇮🇹 · F. Cappuzzello🇮🇹 · D. Carbone🇮🇹 · I. Ciraldo🇮🇹 · A. Pakou🇬🇷 · O. Sgouros🇮🇹 · V. Soukeras🇮🇹 · G. Souliotis🇬🇷 · A. Spatafora🇮🇹 · D. Torresi (for the NUMEN collaboration)

   Physics cases of increasing interest in the recent years, such as the study of double charge exchange reactions for neutrino physics, require the study of very suppressed reaction channels in medium-heavy ion induced nuclear reactions. The main experimental challenges are the possibility to identify and detect the medium-heavy quasi-projectiles and the capability to measure very low cross-sections (few nb) with high sensitivity at very forward angles, including zero degree. The experimental techniques adopted in the setup of the MAGNEX magnetic spectrometer to face these issues are described in this paper.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.B(2020)·43 citations
10. 10*

    Detection Limits of NaI Scintillator Detector Based Aerial Source Detection Systems

    Sebastian Ritter

    Aerial source detection systems have the capability to rapidly provide radiological data over a large area of land. Sodium Iodine (NaI) scintillator based aerial radiation detection systems of compact physical sizes have the potential aid nuclear security applications in a cost-effective manner when deployed on aerial vehicle systems. The Minimum Detectable Activity (MDA) of NaI scintillator airborne detectors is qualitatively evaluated as a function of detector-source distance and as a function of detector-source relative speed. It is found that the MDA increases exponentially with vehicle height and that MDA increases directly proportionally with the relative speed plus the square root of the relative speed. Furthermore, detection limits of an aerial detection system are evaluated in a case study. MDA is evaluated for the nuclear materials U-238 and Pu-239 as defined by the IAEA Safeguards Glossary Table II and MDA is evaluated for arbitrarily selected isotopes found in Table I.2 of the IAEA document TECDOC-1344.

    ↳ physics.ins-detnucl-ex0 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.