arXiv subjects

Hongwei Ke

Publications and source records attributed to Hongwei Ke.

5 recordsLinked to original sources

arXiv2025

The High Level Trigger and Express Data Production at STAR

To meet the demands of the Beam Energy Scan phase-II (BES-II) program, the STAR experiment at RHIC developed a dual real-time framework consisting of a High Level Trigger (HLT) and an Express Data Production system (xProduction). The HLT operates online within the Data Acquisition (DAQ) chain on a multicore CPU cluster, with optional acceleration using Xeon Phi coprocessors. It employs parallelized algorithms, such as the Cellular Automaton track finder, for fast tracking, vertexing, and event filtering, enabling real-time event selection and detector monitoring. In parallel, xProduction runs independently of the DAQ loop and performs near offline-quality calibration and reconstruction within hours. Using the express data stream, enhanced by HLT selections, and the STAR calibration framework, it enables early physics analysis and provides collaboration-wide access to analysis-ready datasets. Together, HLT and xProduction form a complementary system combining real-time selection with rapid high-quality reconstruction. This framework has enabled prompt reconstruction of the ${}^5_{\Lambda}\mathrm{He}$ hypernucleus and efficient processing of large datasets, demonstrating scalability for future high-luminosity experiments.

physics.ins-det↗

arXiv2012

Charge asymmetry dependency of $π^{+}/π^{-}$ elliptic flow in Au + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV

In this proceedings, we present STAR's measurement of $v_{2}$ difference between positively charged pions and negatively charged pions at low transverse momentum for Au + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The integrated $v_2$ of $π^+$ ($π^-$), $0.15 < p_T < 0.5 GeV/c$, decreases (increases) linearly with the increasing charge asymmetry $A_{\pm}$. The $v_2$ difference between $π^+$ and $π^-$ is proportional to $A_{\pm}$ and the slope parameters have their order of magnitude of about 0.01. All of these observed features are consistent with the predication based on Chiral Magnetic Wave. The centrality dependence of the $v_2$ difference is different than that was predicted.

nucl-ex↗

arXiv2009

Critical phenomena in disc-percolation model and its application to relativistic heavy ion collisions

Through studying the critical phenomena in continuum-percolation of discs, we find a new approach to locate the critical point, i.e. using the inflection point of $P_\infty$ as an evaluation of the percolation threshold. The susceptibility, defined as the derivative of $P_\infty$, possess finite-size scaling property, where the scaling exponent is the reciprocal of $ν$ -- the critical exponent of correlation length. The possible application of this approach to the study of the critical phenomena in relativistic heavy ion collisions is discussed. The critical point for deconfinement can be extracted by the inflection point of $P_{\rm QGP}$ -- the probability for the event with QGP formation. The finite-size scaling of its derivative can give the critical exponent $ν$, which is a rare case that can provide an experimental measure of a critical exponent in heavy ion collisions.

hep-ph↗

arXiv2008

Chiral Logarithms in $ΔS=1$ Kaon Decay Amplitudes in General Effective Flavor Theories

We study the chiral logarithms in $ΔS=1$ kaon decay amplitudes from new flavor physics in beyond-standard-model theories. We systematically classify the chiral structures of dimension-5, 6 and 7 effective QCD operators constructed out of light-quark (up, down and strange) and gluon fields. Using the standard chiral perturbation theory, we calculate the leading chiral-logarithms associated with these operators. The result is useful for lattice calculations of the QCD matrix elements in $K\to ππ$ decay necessary, for example, to understand the physical origin of the direct CP violation parameter $ε'$. As a concrete example, we consider the new operators present in minimal left-right symmetric models.

hep-ph↗

arXiv2008

Direct CP Violation in K-decay and Minimal Left-Right Symmetry Scale

We calculate the new contribution to the direct CP-violation parameter $ε'$ in $K\to ππ$ decay in the minimal left-right symmetric model with the recently-obtained right-handed quark Cabibbo-Kobayashi-Maskawa mixing. We pay particular attention to the uncertainty in the hadronic matrix element of a leading four-quark operator $O^{LR}_-$. We find that it can be related to the standard model electromagnetic penguin operator $O_8$ through $SU(3)_L \times SU(3)_R$ chiral symmetry. Using the lattice and large $N_c$ calculations, we obtain a robust constraint on the minimal left-right symmetric scale $M_{W_R}>5$ TeV from the experimental data on $ε'$.

hep-ph↗