The role of longitudinal decorrelations for measurements of anisotropic flow in small collision systems

Within a (3+1)D viscous hydrodynamic model we compute anisotropic flow in small system collisions as performed at the Relativistic Heavy Ion Collider and measured by the STAR and PHENIX Collaborations. We emphasize the importance of the rapidity dependence of the geometry for interpreting the differences encountered in measurements by the two collaborations.Comment: 4 pages; 2 figures; Conference proceedings for Quark Matter 2023, Sept 2023, Houston, Texas, US

Hedge fund market runs during financial crises

Hedge funds exit financial markets simultaneously after enormous shocks, such as the global financial crisis. While previous studies highlight only fund investors’ synchronized withdrawals as the major driver of massive asset liquidations, we primarily focus on informed and rational fund managers and suggest a theoretical model that illustrates fund managers’ synchronized market runs. This study shows that the possibility of runs induces panic-based market runs not because of systematic risk itself but because of the fear of runs. We find that when the market regime changes from a normal to a ‘bad’ state in which runs are possible, hedge funds reduce their investments prior to runs. In addition, market runs are more likely to occur in markets in which hedge funds have greater market exposure and uninformed traders are more sensitive to past price movement

Bulk viscous effects on flow and dilepton radiation in a hybrid approach

Starting from IP-Glasma initial conditions, we investigate the effects of bulk pressure on low mass dilepton production at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) energies. Though thermal dilepton $v_2$ is affected by the presence of both bulk and shear viscosity, whether or not these effects can be measured depends on the dilepton "cocktail" contribution to the the low mass dilepton $v_2$. Combining the thermal and "cocktail" dileptons, the effects of bulk viscosity on total dilepton $v_2$ is investigated.Comment: Proceedings for the 26th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2017), February 5-11 2017, Chicago, Illinois, US

Can Baryon Stopping Be Understood within a Hadronic Transport Approach

The changing shape of the rapidity spectrum of net protons over the SPS energy range is still lacking theoretical understanding. In this work, a model for string excitation and string fragmentation is implemented for the description of high energy collisions within a hadronic transport approach. The free parameters of the string model are tuned to reproduce the experimentally measured particle production in proton-proton collisions. With the fixed parameters we advance to calculations for heavy ion collisions, where the shape of the proton rapidity spectrum changes from a single peak to a double peak structure with increasing beam energy in the experiment. We present calculations of proton rapidity spectra at different SPS energies in heavy ion collisions. Qualitatively, a good agreement with the experimental findings is obtained. In a future work, the formation process of string fragments will be studied in detail aiming to quantitatively reproduce the measurement

Market runs of hedge funds during financial crises

A hedge fund's capital structure is fragile because uninformed fund investors are highly loss sensitive and easily withdraw capital in response to bad news. Hedge fund managers, sharing common investors and interacting with each other through market price, sensitively react to other funds' investment decisions. In this environment, panic-based market runs can arise not because of systematic risk but because of the fear of runs. The authors find that when the market regime changes from a normal state to a "bad" state (in which runs are possible), hedge funds reduce investment prior to runs. In addition, the market runs are more likely to occur in a market where hedge funds hold greater market exposure and uninformed traders have greater sensitivity to past price movement

Bulk Observables within a Hybrid Approach for Heavy Ion Collisions with SMASH Afterburner

We present a model of the dynamical evolution of relativistic heavy ion collisions, which combines second-order viscous hydrodynamics and microscopic transport. In particular, we present a hybrid approach with MUSIC hydrodynamics, and SMASH (Simulating Many Accelerated Strongly-interacting Hadrons) afterburner. In this work, we focus on low- p T hadronic observables—identified hadron p T spectra and anisotropic flow coefficients. We also demonstrate how the hadronic chemistry is altered by the hadronic non-equilibrium dynamics, for example by baryon-antibaryon annihilation. The new MUSIC + SMASH hybrid approach is also compared to existing MUSIC + UrQMD results