Mon·Mar 14, 2022Monday·March 14, 2022

1. 01*

   Study of $\varphi$-meson production in $p$$+$Al, $p$$+$Au, $d$$+$Au, and ${}^3$He$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV

   U. Acharya · A. Adare · C. Aidala · N.N. Ajitanand · Y. Akiba · M. Alfred · V. Andrieux · N. Apadula · H. Asano · B. Azmoun · V. Babintsev · M. Bai and 360 other authors

   Small nuclear collisions are mainly sensitive to cold-nuclear-matter effects; however, the collective behavior observed in these collisions shows a hint of hot-nuclear-matter effects. The identified-particle spectra, especially the $\varphi$ mesons which contain strange and antistrange quarks and have a relatively small hadronic-interaction cross section, are a good tool to study these effects. The PHENIX experiment has measured $\varphi$ mesons in a specific set of small collision systems $p$$+$Al, $p$$+$Au, and ${}^3$He$+$Au, as well as $d$$+$Au [Phys. Rev. C {\bf 83}, 024909 (2011)], at $\sqrt{s_{{}_{NN}}}=200$ GeV. The transverse-momentum spectra and nuclear-modification factors are presented and compared to theoretical-model predictions. The comparisons with different calculations suggest that quark-gluon plasma may be formed in these small collision systems at $\sqrt{s_{{}_{NN}}}=200$ GeV. However, the volume and the lifetime of the produced medium may be insufficient for observing strangeness-enhancement and jet-quenching effects. Comparison with calculations suggests that the main production mechanisms of $\varphi$ mesons at midrapidity may be different in $p$$+$Al versus $p/d/$${}^3$He$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV. While thermal quark recombination seems to dominate in $p/d/$${}^3$He$+$Au collisions, fragmentation seems to be the main production mechanism in $p$$+$Al collisions.

   nucl-exhep-exPRC(2022)·15 citations
2. 02*

   Opportunities for new physics searches with heavy ions at colliders

   David d'Enterria🇨🇭 · Marco Drewes🇧🇪 · Andrea Giammanco🇧🇪 · Jan Hajer🇵🇹 · Elena Bratkovskaya🇩🇪 · Roderik Bruce🇨🇭 · Nazar Burmasov🇷🇺 · Mateusz Dyndal🇵🇱 · Oliver Gould🇬🇧 · Iwona Grabowska-Bold🇵🇱 · Malgorzata Gumberidze🇩🇪 · Taku Gunji🇯🇵 and 6 other authors

   Opportunities for searches for phenomena beyond the Standard Model (BSM) using heavy-ions beams at high energies are outlined. Different BSM searches proposed in the last years in collisions of heavy ions, mostly at the Large Hadron Collider, are summarized. A few concrete selected cases are reviewed including searches for axion-like particles, anomalous $\tau$ electromagnetic moments, magnetic monopoles, and dark photons. Expectations for the achievable sensitivities of these searches in the coming years are given. Studies of CP violation in hot and dense QCD matter and connections to ultrahigh-energy cosmic rays physics are also mentioned.

   ↳ hep-phhep-exnucl-exnucl-thJ.Phys.G(2023)·52 citations
3. 03*

   New Physics searches in a low threshold scintillating argon bubble chamber measuring coherent elastic neutrino-nucleus scattering in reactors

   E. Alfonso-Pita🇲🇽 · L. J. Flores🇲🇽 · Eduardo Peinado🇲🇽 · E. Vázquez-Jáuregui🇲🇽

   The sensitivity to New Physics of a low threshold scintillating argon bubble chamber measuring coherent elastic neutrino-nucleus scattering in reactors is reported. Namely, light scalar mediators, sterile neutrino oscillations, unitarity violation, and non-standard interactions are studied. The results indicate that this detector could be able to set stronger constraints than current limits set by the recent COHERENT measurements. Considering the best scenario, a 100 kg detector located 30 m from a 2000 MW${}_{th}$ reactor, a sterile neutrino search would cover most of the space parameter allowed from the reactor anti-neutrino anomaly fit. Unitarity violation studies could set constraints on ${\alpha }_{11}$ more stringent than the current oscillation experiments fit. A low threshold argon detector with very low backgrounds has the potential to explore New Physics in different scenarios and set competitive constraints.

   ↳ hep-phhep-exnucl-exPRD(2022)·12 citations
4. 04*

   AI for Experimental Controls at Jefferson Lab

   Torri Jeske🇦🇲 · Diana McSpadden🇺🇸 · Nikhil Kalra🇺🇸 · Thomas Britton🇺🇸 · Naomi Jarvis🇺🇸 · David Lawrence🇺🇸

   The AI for Experimental Controls project is developing an AI system to control and calibrate detector systems located at Jefferson Laboratory. Currently, calibrations are performed offline and require significant time and attention from experts. This work would reduce the amount of data and the amount of time spent calibrating in an offline setting. The first use case involves the Central Drift Chamber (CDC) located inside the GlueX spectrometer in Hall D. We use a combination of environmental and experimental data, such as atmospheric pressure, gas temperature, and the flux of incident particles as inputs to a Sequential Neural Network (NN) to recommend a high voltage setting and the corresponding calibration constants in order to maintain consistent gain and optimal resolution throughout the experiment. Utilizing AI in this manner represents an initial shift from offline calibration towards near real time calibrations performed at Jefferson Laboratory.

   ↳ physics.ins-detnucl-exJINST(2022)·7 citations
5. 05*

   Cross sections of removal reactions populating weakly-bound residual nuclei

   J.A. Tostevin🇬🇧

   In many instances, single nucleon removal reactions from neutron-proton asymmetric projectile nuclei populate final states in the residual nuclei that are very weakly bound. Familiar examples include neutron removal reactions from neutron-rich ${}^{11}$Be and ${}^{12}$Be, the latter populating the well-known $1/2^{+}$ halo ground-state and $1/2^{-}$ excited-state of ${}^{11}$Be - both states less than 1 MeV from the first neutron-decay threshold. Numerous additional examples arise in reactions of asymmetric $p$- and $sd$-shell nuclei. The importance of this weak residue binding upon calculated single-nucleon removal reaction cross sections is quantified by means of model calculations that neglect or include the dissociation degree of freedom of the residual nuclei. The calculated removal-reaction cross sections for two representative $p$-shell projectiles indicate that an explicit treatment of these residue break-up effects is unnecessary and that the differences between the break-up and no break-up calculations are small provided a consistent description of the residue structure and density is used.

   ↳ nucl-thnucl-ex0 citations
6. 06*

   Collectivity in Ultra-Peripheral Pb+Pb Collisions at the Large Hadron Collider

   Wenbin Zhao🇺🇸 · Chun Shen🇺🇸 · Björn Schenke🇺🇸

   We present the first full (3+1)D dynamical simulations of ultra-peripheral Pb+Pb collisions at the Large Hadron Collider. Extrapolating from p+Pb collisions, we explore whether a quasi-real photon ${\gamma }^{\ast }$ interacting with the lead nucleus in an ultra-peripheral collision can create a many-body system exhibiting fluid behavior. Assuming strong final-state interactions, we provide model results for charged hadron multiplicity, identified particle mean transverse momenta, and charged hadron anisotropic flow coefficients, and compare them with experimental data from the ALICE and ATLAS collaborations. The elliptic flow hierarchy between p+Pb and ${\gamma }^{\ast }$+Pb collisions is dominated by the difference in longitudinal flow decorrelations and reproduces the experimental data well. We have demonstrated that our theoretical framework provides a quantitative tool to study particle production and collectivity for all system sizes, ranging from central heavy-ion collisions to small asymmetric collision systems at the Relativistic Heavy-Ion Collider and the Large Hadron Collider and even at the future Electron-Ion Collider.

   ↳ nucl-thhep-phnucl-exPRL(2022)·48 citations
7. 07*

   Construction and commissioning of the collinear laser spectroscopy system at BRIF

   S. J. Wang · X. F. Yang🇨🇳 · S. W. Bai🇨🇳 · Y. C. Liu · P. Zhang · Y. S. Liu🇨🇳 · H. R. Hu🇨🇳 · H. W. Li🇨🇳 · B. Tang🇨🇳 · B. Q. Cui · C. Y. He🇨🇳 · X. Ma and 15 other authors

   We have constructed a collinear laser spectroscopy (CLS) system installed at the Beijing Radioactive Ion-beam Facility (BRIF), aiming to investigate the nuclear properties of unstable nuclei. The first on-line commissioning experiment of this system was performed using the continuous stable (${}^{39}$K) and unstable (${}^{38}$K) ion beams produced by impinging a 100-MeV proton beam on a CaO target. Hyperfine structure spectra of these two isotopes are reasonably reproduced, and the extracted magnetic dipole hyperfine parameters and isotope shift agree with the literature values. The on-line experiment demonstrates the overall functioning of this CLS system, opening new opportunities for laser spectroscopy measurement of unstable isotopes at BRIF and other radioactive ion beam facilities in China.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2022)·8 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.