Mon·Jun 24, 2019Monday·June 24, 2019

1. 01*

   Charm and beauty isolation from heavy flavor decay electrons in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV at RHIC

   Fan Si🇨🇳 · Xiao-Long Chen🇨🇳 · Long Zhou🇨🇳 · Yi-Fei Zhang🇨🇳 · Sheng-Hui Zhang🇨🇳 · Xin-Yue Ju🇨🇳 · Xiu-Jun Li🇨🇳 · Xin Dong🇺🇸 · Nu Xu🇨🇳

   We present a study of charm and beauty isolation based on a data-driven method with recent measurements on heavy flavor hadrons and their decay electrons in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV at RHIC. The individual electron $p_{\mathrm{T}}$ spectra, $R_{\mathrm{AA}}$ and $v_2$ distributions from charmed and beauty hadron decays are obtained. We find that the electron $R_{\mathrm{AA}}$ from beauty hadron decays ($R_{\mathrm{AA}}^{\mathrm{b}\to \mathrm{e}}$) is suppressed in minimum bias Au+Au collisions but less suppressed compared with that from charmed hadron decays at $p_{\mathrm{T}}$ $>$ 3.5 GeV/$c$, which indicates that beauty quark interacts with the hot-dense medium with depositing its energy and is consistent with the mass-dependent energy loss scenario. For the first time, the non-zero electron $v_2$ from beauty hadron decays ($v_2^{\mathrm{b}\to \mathrm{e}}$) at $p_{\mathrm{T}}$ $>$ 3.0 GeV/$c$ is observed and shows smaller elliptic flow compared with that from charmed hadron decays at $p_{\mathrm{T}}$ $<$ 4.0 GeV/$c$. At 2.5 GeV/$c$ $<$ $p_{\mathrm{T}}$ $<$ 4.5 GeV/$c$, $v_2^{\mathrm{b}\to \mathrm{e}}$ is smaller than a number-of-constituent-quark (NCQ) scaling hypothesis. This suggests that beauty quark is unlikely thermalized and too heavy to be moved in a partonic collectivity in heavy-ion collisions at the RHIC energy.

   nucl-exPLB(2020)·12 citations
2. 02*

   Beam-energy dependence of identified two-particle angular correlations in Au+Au collisions at RHIC

   STAR Collaboration: J. Adam · L. Adamczyk · J. R. Adams · J. K. Adkins · G. Agakishiev · M. M. Aggarwal · Z. Ahammed · I. Alekseev · D. M. Anderson · A. Aparin · E. C. Aschenauer · M. U. Ashraf and 344 other authors

   The two-particle angular correlation functions, $R_2$, of pions, kaons, and protons in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV were measured by the STAR experiment at RHIC. These correlations were measured for both like-sign and unlike-sign charge combinations and versus the centrality. The correlations of pions and kaons show the expected near-side ({\it i.e.}, at small relative angles) peak resulting from short-range mechanisms. The amplitudes of these short-range correlations decrease with increasing beam energy. However, the proton correlation functions exhibit strong anticorrelations in the near-side region. This behavior is observed for the first time in an A+A collision system. The observed anticorrelation is $p_T$-independent and decreases with increasing beam energy and centrality. The experimental results are also compared to the Monte Carlo models UrQMD, Hijing, and AMPT.

   nucl-exPRC(2020)·17 citations
3. 03*

   Measuring Momentum-Dependent Flow Fluctuations in Heavy-Ion Collisions

   Mauricio Hippert🇧🇷 · David Dobrigkeit Chinellato🇧🇷 · Matthew Luzum🇧🇷 · Jorge Noronha🇧🇷 · Tiago Nunes da Silva🇧🇷 · Jun Takahashi🇧🇷

   In heavy-ion collisions, momentum-dependent pair correlations can be characterized by a principal component analysis (PCA), in which subleading modes are expected to reveal new information on flow fluctuations. However, we find that, as currently measured, these modes can be dominated by multiplicity fluctuations, which serve as an unwanted background. Here, we propose new PCA observables that are robust against multiplicity fluctuations and isolate novel sources of flow fluctuations, thus being suited to provide fresh insight into the initial stages of the system at small length scales.

   ↳ nucl-thhep-phnucl-exPRC(2020)·15 citations
4. 04*

   Elliptic flow in ultra-relativistic collisions with light polarized nuclei

   Wojciech Broniowski🇵🇱 · Piotr Bozek🇵🇱

   Estimates for elliptic flow in collisions of polarized light nuclei with spin $j\ge 1$ with a heavy nucleus are presented. In such collisions the azimuthal symmetry is broken via polarization of the wave function of the light nucleus, resulting in nonzero one-body elliptic flow coefficient evaluated relative to the polarization axis. Our estimates involve experimentally well known features of light nuclei, such as their quadrupole moment and the charge radius, yielding the one-body elliptic flow coefficient in the range from 1\% for collisions with the deuteron to 5\% for for collisions with ${}^{10}$B nucleus. Prospects of addressing the issue in the upcoming fixed-target experiment at the Large Hadron Collider are discussed.

   ↳ nucl-thnucl-exPRC(2020)·15 citations
5. 05*

   Long Term Logarithmic Annealing in p-MNOS RADFETs and Renormalization of Relaxation Parameters

   G. I. Zebrev · P. A. Zimin · E. V. Mrozovskaya · V. A. Yushkova · V. S. Anashin · P. A. Chubunov

   It was experimentally shown that annealing (fading) of the pMNOS based dosimeters has close to logarithmic temporal dependence during and after irradiation. The results are shown to be consistent with the previously proposed model.

   ↳ physics.app-phnucl-exphysics.ins-detphysics.space-ph0 citations
6. 06*

   ${}^7$Be and ${}^7$Li nuclei within the no-core shell model with continuum

   Matteo Vorabbi🇨🇦 · Petr Navrátil🇨🇦 · Sofia Quaglioni🇺🇸 · Guillaume Hupin🇫🇷

   The production of ${}^7$Be and ${}^7$Li nuclei plays an important role in primordial nucleosynthesis, nuclear astrophysics, and fusion energy generation. The ${}^3\mathrm{He}(\alpha ,\gamma {)}^7\mathrm{Be}$ and ${}^3\mathrm{H}(\alpha ,\gamma {)}^7\mathrm{Li}$ radiative-capture processes are important to determine the ${}^7$Li abundance in the early universe and to predict the correct fraction of pp-chain branches resulting in ${}^7$Be versus ${}^8$B neutrinos. In this work we study the properties of ${}^7$Be and ${}^7$Li within the no-core shell model with continuum (NCSMC) method, using chiral nucleon-nucleon interactions as the only input, and analyze all the binary mass partitions involved in the formation of these systems. The NCSMC is an ab initio method applicable to light nuclei that provides a unified description of bound and scattering states and thus is well suited to investigate systems with many resonances and pronounced clustering like ${}^7$Be and ${}^7$Li. Our calculations reproduce all the experimentally known states of the two systems and provide predictions for several new resonances of both parities. Some of these new possible resonances are built on the ground states of ${}^6$Li and ${}^6$He, and thus represent a robust prediction. We do not find any resonance in the p${+}^6$Li mass partition near the threshold. On the other hand, in the p${+}^6$He mass partition of ${}^7$Li we observe an $S$-wave resonance near the threshold producing a very pronounced peak in the calculated S factor of the ${}^6\mathrm{He}(\mathrm{p},\gamma {)}^7\mathrm{Li}$ radiative-capture reaction, which could be relevant for astrophysics and its implications should be investigated.

   ↳ nucl-thnucl-exPRC(2019)·42 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.