A. Francisco
A5027836924- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Nuclear reactor physics and engineering
- Particle Detector Development and Performance
- Fusion materials and technologies
- Stochastic processes and statistical mechanics
- Superconducting Materials and Applications
- Dark Matter and Cosmic Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Pulsars and Gravitational Waves Research
- Radioactive Decay and Measurement Techniques
- Plasma Diagnostics and Applications
- Theoretical and Computational Physics
- Nuclear physics research studies
- Markov Chains and Monte Carlo Methods
- Cosmology and Gravitation Theories
- Gas Dynamics and Kinetic Theory
- Fluid Dynamics and Turbulent Flows
- Astrophysics and Cosmic Phenomena
- Spectroscopy and Laser Applications
- Particle Accelerators and Free-Electron Lasers
- Crystallography and Radiation Phenomena
- Computational Physics and Python Applications
- Advanced Data Storage Technologies
CEA Grenoble
2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2022-2024
CEA Cadarache
2024
Yale University
2020-2023
Centre National de la Recherche Scientifique
2016-2022
A. Alikhanyan National Laboratory
2017-2022
Laboratoire de Physique Corpusculaire
2021-2022
Université Clermont Auvergne
2022
Université Paris-Saclay
2022
Institut de Recherche sur les Lois Fondamentales de l'Univers
2022
Non-monotonic variation with collision energy ($\sqrt{s_{\rm NN}}$) of the moments net-baryon number distribution in heavy-ion collisions, related to correlation length and susceptibilities system, is suggested as a signature for Quantum Chromodynamics (QCD) critical point. We report first evidence non-monotonic kurtosis times variance net-proton (proxy number) function \rootsnn 3.1$\sigma$ significance, head-on (central) gold-on-gold (Au+Au) collisions measured using STAR detector at RHIC....
The Breit-Wheeler process which produces matter and anti-matter from photon collisions is investigated experimentally through the observation of 6085 exclusive electron-positron pairs in ultra-peripheral Au+Au at $\sqrt{s_{_{NN}}}=200$ GeV. measurements reveal a large fourth-order angular modulation $\cos{4\Delta\phi}=(16.8\pm2.5)\%$ smooth invariant mass distribution absent vector mesons ($\phi$, $\omega$ $\rho$) experimental limit $\le 0.2\%$ observed yields. differential cross section as...
We report a systematic measurement of cumulants, $C_{n}$, for net-proton, proton and antiproton multiplicity distributions, correlation functions, $\kappa_n$, distributions up to the fourth order in Au+Au collisions at $\sqrt{s_{\mathrm {NN}}}$ = 7.7, 11.5, 14.5, 19.6, 27, 39, 54.4, 62.4 200 GeV. The $C_{n}$ $\kappa_n$ are presented as function collision energy, centrality kinematic acceptance rapidity, $y$, transverse momentum, $p_{T}$. data were taken during first phase Beam Energy Scan...
Global polarization of Ξ and Ω hyperons has been measured for the first time in Au+Au collisions at sqrt[s_{NN}]=200 GeV. The measurements Ξ^{-} Ξ[over ¯]^{+} hyperon have performed by two independent methods, via analysis angular distribution daughter particles parity violating weak decay Ξ→Λ+π, as well measuring Λ hyperon, polarized transfer from its parent. polarization, obtained combining results methods averaged over ¯]^{+}, is to be ⟨P_{Ξ}⟩=0.47±0.10(stat)±0.23(syst)% collision...
We report on the first measurement of charmed baryon Λ_{c}^{±} production at midrapidity (|y|<1) in Au+Au collisions sqrt[s_{NN}]=200 GeV collected by STAR experiment Relativistic Heavy Ion Collider. The Λ_{c}/D^{0} [denoting (Λ_{c}^{+}+Λ_{c}^{-})/(D^{0}+D[over ¯]^{0})] yield ratio is measured to be 1.08±0.16 (stat)±0.26 (sys) 0%-20% most central for transverse momentum (p_{T}) range 3<p_{T}<6 GeV/c. This significantly larger than pythia model calculations p+p collisions. ratio, as a...
We report on the measurements of directed flow $v_1$ and elliptic $v_2$ for hadrons ($\pi^{\pm}$, $K^{\pm}$, $K_{S}^0$, $p$, $\phi$, $\Lambda$ $\Xi^{-}$) from Au+Au collisions at $\sqrt{s_{NN}}$ = 3\,GeV $v_{2}$ $p$ $\overline{p}$) 27 54.4\,GeV with STAR experiment. While two higher energy midcentral number-of-constituent-quark (NCQ) scaling holds, midrapidity is negative all NCQ absent. In addition, slopes almost observed are found to be positive, implying dominant repulsive baryonic...
The beam energy scan (BES) program at the BNL Relativistic Heavy Ion Collider (RHIC) was extended to energies below $\sqrt{{s}_{NN}}=7.7$ GeV in 2015 by successful implementation of fixed-target mode operation STAR (Solenoidal Tracker At RHIC) experiment. In this mode, ions circulate one ring collider and interact with a stationary target entrance time projection chamber. first results for $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=4.5$ are presented, demonstrating good...
The chiral magnetic effect (CME) refers to charge separation along a strong field due imbalanced chirality of quarks in local parity and charge-parity violating domains quantum chromodynamics. experimental measurement the is made difficult by presence major background from elliptic azimuthal anisotropy. This CME signal have different sensitivities spectator participant planes, could thus be determined measurements with respect these planes. We report such Au+Au collisions at nucleon-nucleon...
In high-energy heavy-ion collisions, partonic collectivity is evidenced by the constituent quark number scaling of elliptic flow anisotropy for identified hadrons. A breaking this and dominance baryonic interactions found hadron collective measurements in $\sqrt{s_{\rm NN}}$ = 3 GeV Au+Au collisions. paper, we report first- second-order azimuthal anisotropic parameters, $v_1$ $v_2$, light nuclei ($d$, $t$, $^{3}$He, $^{4}$He) produced collisions at STAR experiment. An atomic mass measured...
Squirrels and chipmunks are known to have mycophagous habits. Nonetheless, records of mycopaghy involving these animals not always present the fungal species involved, specially when they epigeous mushrooms in Neotropical forests. Here, we report events mycophagy Brazilian squirrel (Guerlinguetus brasiliensis) coconut mushroom (Oudemansiella cubensis), including description event presenting photographs. The aim this study is discuss habit squirrel.
The STAR Collaboration at the Relativistic Heavy Ion Collider reports first measurement of inclusive jet production in peripheral and central Au+Au collisions $\sqrt{{s}_{NN}}=200$ GeV. Jets are reconstructed with anti-${k}_{T}$ algorithm using charged tracks pseudorapidity $|\ensuremath{\eta}|<1.0$ transverse momentum $0.2<{p}_{T,\mathrm{jet}}^{\mathrm{ch}}<30$ $\mathrm{GeV}/c$, resolution parameter $R=0.2$, 0.3, 0.4. large background yield uncorrelated signal is observed to be dominated by...
According to first-principle lattice QCD calculations, the transition from quark-gluon plasma hadronic matter is a smooth crossover in region μB≤Tc. In this range ratio, C6/C2, of net-baryon distributions are predicted be negative. Letter, we report first measurement midrapidity net-proton C6/C2 27, 54.4, and 200 GeV Au+Au collisions at Relativistic Heavy Ion Collider (RHIC). The dependence on collision centrality kinematic acceptance (pT, y) analyzed. While for 27 54.4 values close zero...
We report the first multi-differential measurements of strange hadrons K−, ϕ and Ξ− yields as well ratios ϕ/K− ϕ/Ξ− in Au+Au collisions at sNN=3 GeV with STAR experiment fixed target configuration RHIC. The mesons hyperons are measured through hadronic decay channels, ϕ→K+K− Ξ−→Λπ−. Collision centrality rapidity dependence transverse momentum spectra for these presented. 4π compared to thermal model transport predictions. At this collision energy, grand canonical ensemble (GCE)...
R&D efforts are ongoing to develop the Cylindrical Micromegas Barrel Layer (CyMBaL) for central region of ePIC detector, first experiment at future Electron Ion Collider (EIC). The detectors will be part a multi-technology tracker located inside 1.7 T solenoid, bringing stringent limits on space. Constraints momentum reconstruction performances also impose low-material budget in order not degrade measurements placed behind. As such, light resistive equipped with 2D readout is needed. goal...
In this letter, measurements of the shared momentum fraction (zg) and groomed jet radius (Rg), as defined in SoftDrop algorithm, are reported p+p collisions at s=200 GeV collected by STAR experiment. These substructure observables differentially measured for jets varying resolution parameters from R=0.2−0.6 transverse range 15<pT,jet<60 GeV/c. studies show that, pT,jet accessible with increasing parameter momentum, zg distribution asymptotically converges to DGLAP splitting kernel a quark...
We report systematic measurements of bulk properties the system created in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=14.5$ GeV recorded by STAR detector Relativistic Heavy Ion Collider (RHIC). The transverse momentum spectra ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}, {K}^{\ifmmode\pm\else\textpm\fi{}}$, and $p(\overline{p})$ are studied midrapidity ($|y|<0.1$) for nine centrality intervals. centrality, (${p}_{T}$), pseudorapidity ($\ensuremath{\eta}$) dependence...
We report on the first measurement of charm-strange meson $D_s^{\pm}$ production at midrapidity in Au+Au collisions $\sqrt{s_{_{\rm NN}}}$ = 200 GeV from STAR experiment. The yield ratio between strange ($D_{s}^{\pm}$) and non-strange ($D^{0}$) open-charm mesons is presented compared to model calculations. A significant enhancement, relative a PYTHIA simulation $p$+$p$ collisions, observed $D_{s}^{\pm}/D^0$ over large range collision centralities. Model calculations incorporating abundant...
Understanding gluon density distributions and how they are modified in nuclei among the most important goals nuclear physics. In recent years, diffractive vector meson production measured ultraperipheral collisions (UPCs) at heavy-ion colliders has provided a new tool for probing density. this Letter, we report first measurement of J/ψ photoproduction off deuteron UPCs center-of-mass energy sqrt[s_{NN}]=200 GeV d+Au collisions. The differential cross section as function momentum transfer -t...
We report measurements of the longitudinal double-spin asymmetry, ${A}_{LL}$, for inclusive jet and dijet production in polarized proton-proton collisions at midrapidity center-of-mass energy $\sqrt{s}=510\text{ }\text{ }\mathrm{GeV}$, using high luminosity data sample collected by STAR experiment 2013. These complement improve precision previous same that probe gluon distribution function partonic momentum fraction $0.015\ensuremath{\lesssim}x\ensuremath{\lesssim}0.25$. The asymmetries are...
We report on the $W$ and $Z/\gamma^*$ differential total cross sections as well $W^+$/$W^-$ $(W^+ + W^-)$/$(Z/\gamma^*)$ cross-section ratios measured by STAR experiment at RHIC in $p+p$ collisions $\sqrt{s} = 500$ GeV $510$ GeV. The their are sensitive to quark antiquark parton distribution functions. In particular, leading order, ratio is $\bar{d}/\bar{u}$ ratio. These measurements were taken high $Q^2 \sim M_W^2,M_Z^2$ can serve input into global analyses provide constraints sea...
The STAR Collaboration reports measurements of the transverse single-spin asymmetry (TSSA) inclusive $\pi^0$ at center-of-mass energies ($\sqrt s$) 200 GeV and 500 in transversely polarized proton-proton collisions pseudo-rapidity region 2.7 to 4.0. results two different show a continuous increase TSSA with Feynman-$x$, and, when compared previous measurements, no dependence on $\sqrt s$ from 19.4 is found. To investigate underlying physics leading this large TSSA, topologies have been...
We report high-precision measurements of the longitudinal double-spin asymmetry, $A_{LL}$, for midrapidity inclusive jet and dijet production in polarized $pp$ collisions at a center-of-mass energy $\sqrt{s}=200\,\mathrm{GeV}$. The new data are sensitive to gluon helicity distribution, $\Delta g(x,Q^2)$, momentum fractions range from $x \simeq 0.05$ 0.5$, while provide further constraints on $x$ dependence g(x,Q^2)$. results good agreement with previous $\sqrt{s}=200\,\mathrm{GeV}$ recent...
Various models of the QCD phase diagram favor a first-order transition to quark-gluon plasma, and therefore critical endpoint which could manifest itself in measurable fluctuations correlations. The authors report measurements moments net proton multiplicity (cumulants) correlation functions from RHIC beam energy scan. They establish that at $\sqrt{{s}_{N\phantom{\rule{0}{0ex}}N}}=3$ GeV produced system is dominated by hadronic rather than thermal interactions. This puts limit on search for...