I report the most recent measurements on open heavy flavor production at RHIC on behalf of the STAR collaboration. The total charm production cross section in midrapidity at RHIC energy is found to approximately scale by number of binary collisions in d + Au, Cu + Cu and Au + Au collisions. The nuclear modification factor of non-photonic electrons is strongly suppressed in central Au + Au collisions, suggesting substantial heavy quark energy loss at RHIC. The bottom decay contribution to non-photonic electrons was studied via the e-h and e-D 0 azimuthal angular correlations. The bottom contribution is found to be important at p T >5 GeV/c, and is consistent with the FONLL calculation within uncertainties. Charm production through gluon jet splitting was measured by studying the D ± contents in the fully reconstructed jets in p+p collisions. This rate is consistent with pQCD evaluation of gluon splitting into a pair of charm quarks and subsequent hadronization. © 2009 Springer-Verlag / Società Italiana di Fisica.

I review the latest heavy flavor measurements at RHIC experiments. Measurements from RHIC together with preliminary results from LHC offer us an opportunity to systematically study the sQGP medium properties. In the end, I will outlook a prospective future on precision heavy flavor measurements with detector upgrades at RHIC.

Heavy quarks (HQ) are believed to have unique roles for studying QCD at finite temperature and baryon density. By comparing precision measurements of HQ hadron production in heavy-ion collisions with realistic phenomenological model calculations, the goal is to understand interactions and dynamics of HQ propagating through the Quark–Gluon Plasma (QGP) medium and furthermore to characterize the QGP with emergent QCD transport parameters and their temperature dependence. In this article, we will review recent experimental and theoretical achievements on HQ production in high energy p + p, p∕d + A and A + A collisions at RHIC and the LHC. We will discuss what we have learned about the HQ production and how HQs interact with the QGP medium along with their QGP medium properties. Finally, we would like to discuss a few open questions and propose future experimental and theoretical directions towards the physics goals utilizing HQ probes.

Indiscriminate drug administration may lead to drug therapy results with varying effects on patients, and the proposal of personalized medication can help patients to receive effective drug therapy. Conventional ways of personalized medication, such as pharmacogenomics and therapeutic drug monitoring (TDM), can only be implemented from a single perspective. The development of pharmacometabolomics provides a research method for the realization of precise drug administration, which integrates the environmental and genetic factors, and applies metabolomics technology to study how to predict different drug therapeutic responses of organisms based on baseline metabolic levels. The published research on pharmacometabolomics has achieved satisfactory results in predicting the pharmacokinetics, pharmacodynamics, and the discovery of biomarkers of drugs. Among them, the pharmacokinetics related to pharmacometabolomics are used to explore individual variability in drug metabolism from the level of metabolism of the drugs in vivo and the level of endogenous metabolite changes. By searching for relevant literature with the keyword pharmacometabolomics on the two major literature retrieval websites, PubMed and Web of Science, from 2006 to 2023, we reviewed articles in the field of pharmacometabolomics that incorporated pharmacokinetics into their research. This review explains the therapeutic effects of drugs on the body from the perspective of endogenous metabolites and pharmacokinetic principles, and reports the latest advances in pharmacometabolomics related to pharmacokinetics to provide research ideas and methods for advancing the implementation of personalized medication.

Study of the transverse structure of the proton is one of the major physics goals of the upcoming electron ion collider (EIC). The gluon transverse momentum dependent distributions (TMDs) form an essential focus of this effort and are important towards understanding the angular momentum contribution to proton spin as well as QCD factorization. However, very limited experimental constraints on the gluon TMDs exist currently. As the heavy quark production in lepton-nucleon DIS gets a dominant contribution from the photon-gluon-fusion process, heavy quark production makes an attractive tool to probe gluon distributions in nucleons. In this paper we present a study of heavy flavor hadron pair reconstruction at a future EIC detector with MAPS based inner tracking and vertexing subsystems to constrain gluon TMDs. We utilize the excellent track pointing resolution provided by the detector to exclusively reconstruct heavy flavor hadron pairs via their hadronic decay channels and also to develop a heavy flavor hadron tagging algorithm. Statistical uncertainty projections on azimuthal asymmetries corresponding to gluon TMDs at the EIC is evaluated. The heavy flavor tagging is found to substantially enhance the purity of heavy flavor hadron pair selection, and the statistical precision of the measurement compared to that from exclusive reconstruction. The correlation between the azimuthal angle of the transverse momentum of the gluon initiating the process and that of the corresponding heavy flavor hadron pair was also studied and found to be well correlated. This study opens up heavy flavor hadron pair measurements as an attractive channel to access gluon TMDs at the EIC.

In backward photoproduction of mesons, the produced vector meson takes most of the struck nucleon momentum. The nucleon loses most of its momentum, and so is shifted several units of rapidity. Thus the Mandelstam u is small, while the squared momentum transfer t is typically large, near the kinematic limit. In a collider geometry, backward production transfers the struck baryon by many units of rapidity, in a striking similarity to baryon stopping. We explore this similarity, and point out the similarities between the Regge theories used to model baryon stopping with those that are used for backward production. We then explore how backward production can be explored at higher energies than are available at fixed target experiments, by studying production at an electron-ion collider. We calculate the expected ep cross sections and rates, finding that the rate for backward ω production is about 1/300 that of forward ωs. We discuss the kinematics of backward production and consider the detector requirements for experimental study. We demonstrate that an experiment at the proposed U.S. Electron-Ion Collider will have the capability to detect backward-production events and may provide a test for models of stopping in high-energy ep collisions including the baryon-junction model.

The Electron-Ion Collider (EIC) at Brookhaven National Laboratory will be a precision quantum chromodynamics machine that will enable a vast physics program with electron+proton/ion collisions across a broad center-of-mass range. Measurements of hard probes such as heavy flavor in deep inelastic scatterings will be an essential component to the EIC physics program and are one of the detector R&D driving aspects. In this paper we study the projected statistical precision of open charm hadron production through exclusive hadronic channel reconstruction with a silicon detector concept currently being developed using a pythia-based simulation. We further study the impact of possible intrinsic charm in the proton on projected data, and estimate the constraint on the nuclear gluon parton distribution function (PDF) from the charm structure functions F2cc¯ in e+Au collisions using a Bayesian PDF reweighting technique. Our studies show the EIC will be capable of delivering an unprecedented measurement of charm hadron production across a broad kinematic region and will provide strong constraints to both intrinsic charm and nuclear gluon PDFs.

High-energy backward (u-channel) reactions can involve very large momentum transfers to the target baryons, shifting them by many units of rapidity. These reactions are difficult to understand in conventional models in which baryon number is carried by the valence quarks. Backward Compton scattering is an especially attractive experimental target, because of its simple final state. There is currently limited data on this process, and those data are at low center-of-mass energies. In this paper, we examine the prospects for studying backward Compton scattering at the future Electron Ion Collider (EIC). We model the cross section and kinematics using the limited data on backward Compton scattering and backward meson production, and then simulate Compton scattering at EIC energies in a simple model of the ePIC detector. Generally, the proton is scattered toward midrapidity, while the produced photon is in the far-forward region, visible in a Zero Degree Calorimeter (ZDC). We show that the background from backward π0 production can be rejected using a high-resolution, well-segmented ZDC.

The discovery of borospherenes unveiled the capacity of boron to form fullerene-like cage structures. While fullerenes are known to entrap metal atoms to form endohedral metallofullerenes, few metal atoms have been observed to be part of the fullerene cages. Here we report the observation of a class of remarkable metallo-borospherenes, where metal atoms are integral parts of the cage surface. We have produced La₃B₁₈^- and Tb₃B₁₈^- and probed their structures and bonding using photoelectron spectroscopy and theoretical calculations. Global minimum searches revealed that the most stable structures of Ln₃B₁₈^- are hollow cages with D_3h symmetry. The B₁₈-framework in the Ln₃B₁₈^- cages can be viewed as consisting of two triangular B₆ motifs connected by three B₂ units, forming three shared B₁₀ rings which are coordinated to the three Ln atoms on the cage surface. These metallo-borospherenes represent a new class of unusual geometry that has not been observed in chemistry heretofore.