Digital Commons Network^™

Tuning Microwave Losses In Superconducting Resonators, Alex Gurevich

Physics Faculty Publications

Performance of superconducting resonators, particularly cavities for particle accelerators and micro cavities and thin film resonators for quantum computations and photon detectors has been improved substantially by recent materials treatments and technological advances. As a result, the niobium cavities have reached the quality factors Q ~ 10¹¹ at 1-2 GHz and 1.5 K and the breakdown radio-frequency (rf) fields H close to the dc superheating eld of the Meissner state. These advances raise the question whether the state-of-the-art cavities are close to the fundamental limits, what these limits actually are, and to what extent the Q and H limits …

Scattered Spectra From Inverse Compton Sources Operating At High Laser Fields And High Electron Energies, Geoffrey A. Krafft, Balša Terzić, Erik Johnson, G. Wilson

Physics Faculty Publications

As Compton x-ray and gamma-ray sources become more prevalent, to understand their performance in a precise way, it becomes important to be able to compute the distribution of scattered photons precisely. For example, codes have been developed at Old Dominion University which were used to understand the performance of the Dresden Compton Source in detail. An ideal model would (i) include the full Compton effect frequency relations between incident and scattered photons, (ii) allow the field strength to be large enough that nonlinear effects are captured, and (iii) allow the effects of electron beam emittance to be introduced and studied. …

Non-Singlet Quark Helicity Pdfs Of The Nucleon From Pseudo-Distributions, Robert Edwards, Colin Egerer, Joseph Karpie, Nikhil Karthik, Christopher Monahan, Wayne Morris, Kostas Orginos, Anatoly Radyushkin, David Richards, Eloy Romero, Raza Sabbir Sufian, Savvas Zafeiropoulos, On Behalf Of The Hadstruc Collaboration

Physics Faculty Publications

The non-singlet helicity quark parton distribution functions (PDFs) of the nucleon are determined from lattice QCD, by jointly leveraging pseudo-distributions and the distillation spatial smearing paradigm. A Lorentz decomposition of appropriately isolated space-like matrix elements reveals pseudo-distributions that contain information on the leading-twist helicity PDFs, as well as an invariant amplitude that induces an additional z² contamination of the leading-twist signal. An analysis of the short-distance behavior of the space-like matrix elements using matching coefficients computed to next-to-leading order (NLO) exposes the desired PDF up to this additional z² contamination. Due to the non-conservation of the axial current, …

Foundations Of Wave Phenomena: Complete Version, Charles G. Torre

Foundations of Wave Phenomena

This is the complete version of Foundations of Wave Phenomena. Version 8.3.1.

Please click here to explore the components of this work.

Analysis Of Biologically Effective Dose For Retroactive Yttrium-90 Trans-Arterial Radioembolization Treatment Optimization, Mj Lindsey

CMC Senior Theses

Trans-arterial radioembolization (TARE) is a protracted modality of radiation therapy where radionuclides labeled with Yttrium-90 (⁹⁰Y) are inserted inside a patient's hepatic artery to treat hepatocellular carcinoma (HCC). While TARE has been shown to be a clinically effective and safe treatment, there is little understanding of the radiobiological relationship between absorbed dose and tissue response, and thus there is no dosimetric standard for treatment planning. The Biologically Effective Dose (BED) formalism, derived from the Linear-Quadratic model of radiobiology, is used to weigh the absorbed dose by the time pattern of delivery. BED is a virtual dose that can …

Effect Of Decorating Super Paramagnetic Iron Oxide Nanoparticles With Silver Nanoparticles On Their Magneto-Photo Thermal Heating Efficiency, Anthony Joseph Afful

All Graduate Theses, Dissertations, and Other Capstone Projects

Cancer treatment is rather dangerous to the body, often involving many secondary effects, including nausea, hair loss, and weight fluctuations. The search for non-invasive, highly efficient, and targetable treatments ameliorates these issues. Super paramagnetic iron oxide nanoparticles (SPIONS) have been used for other medical purposes such as magnetic resonance imaging contrast agent and is being extensively studied as a potential candidate for many cancer therapeutic and diagnostic approaches due to its biocompatibility and superior magnetic properties. When subjected to an external alternating magnetic field SPIONS generate heat mainly due to the friction of the SPIONS against the fluid it is …

More On The Demons Of Thermodynamics, Daniel P. Sheehan, Garret Moddel, James W. Lee

Chemistry & Biochemistry Faculty Publications

No abstract provided.

Escape Dynamics Of Confined Undulating Worms, Animesh Biswas, Arshad Kudrolli

Physics

We investigate the escape dynamics of oligochaeta Lumbriculus variegatus by confining them to a quasi-2D circular chamber with a narrow exit passage. The worms move by performing undulatory and peristaltic strokes and use their head to actively probe their surroundings. We show that the worms follow the chamber boundary with occasional reversals in direction and with velocities determined by the orientation angle of the body with respect to the boundary. The average time needed to reach the passage decreases with its width before approaching a constant, consistent with a boundary-following search strategy. We model the search dynamics as a persistent …

Dissolution-Driven Propulsion Of Floating Solids, Martin Chaigne, Michael Berhanu, Arshad Kudrolli

Physics

We show that unconstrained asymmetric dissolving solids floating in a fluid can move rectilinearly as a result of attached density currents which occur along their inclined surfaces. Solids in the form of boats composed of centimeter-scale sugar and salt slabs attached to a buoy are observed to move rapidly in water with speeds up to 5 mm/s determined by the inclination angle and orientation of the dissolving surfaces. While symmetric boats drift slowly, asymmetric boats are observed to accelerate rapidly along a line before reaching a terminal velocity when their drag matches the thrust generated by dissolution. By visualizing the …

Recent Advances In Experimental Design And Data Analysis To Characterize Prokaryotic Motility, Megan M. Dubay, Jacqueline Acres, Max Riekeles, Jay Nadeau

Physics Faculty Publications and Presentations

Bacterial motility plays a key role in important cell processes such as chemotaxis and biofilm formation, but is challenging to quantify due to the small size of the individual microorganisms and the complex interplay of biological and physical factors that influence motility phenotypes. Swimming, the first type of motility described in bacteria, still remains largely unquantified. Light microscopy has enabled qualitative characterization of swimming patterns seen in different strains, such as run and tumble, run-reverse-flick, run and slow, stop and coil, and push and pull, which has allowed for elucidation of the underlying physics. However, quantifying these behaviors (e.g., identifying …

A Jwst/Nirspec Exploration Of The Connection Between Ionization Parameter, Electron Density, And Star-Formation-Rate Surface Density In Z = 2.7–6.3 Galaxies, Naveen Reddy, Michael W. Topping, Ryan L. Sanders, Alice E. Shapley, Gabriel B. Brammer

Physics and Astronomy Faculty Publications

We examine the factors responsible for the variation in the ionization parameter (U) of high-redshift star-forming galaxies based on medium-resolution JWST/NIRSpec observations obtained by the Cosmic Evolution Early Release Science survey. The sample consists of 48 galaxies with redshifts zspec = 2.7−6.3, which are largely representative of typical galaxies at these redshifts. The [S II] λλ6718, 6733 doublet is used to estimate electron densities (n e), and dust-corrected Hα luminosities are used to compute ionizing photon rates (Q). Using composite spectra of galaxies in bins of [O III] λλ4960, 5008/[O II] λλ3727, 3730 (O32) as a proxy for U, we …

An Updated Dust-To-Star Geometry: Dust Attenuation Does Not Depend On Inclination In 1.3 <= Z <= 2.6 Star-Forming Galaxies From Mosdef, Brian Lorenz, Mariska Kriek, Alice E. Shapley, Naveen Reddy, Ryan L. Sanders, Guillermo Barro, Alison L. Coil, Bahram Mobasher, Sedona H. Price, Jordan N. Runco, Irene Shivaei, Brian Siana, Daniel R. Weisz

Physics and Astronomy Faculty Publications

We investigate dust attenuation and its dependence on viewing angle for 308 star-forming galaxies at 1.3 < = z < = 2.6 from the MOSFIRE Deep Evolution Field survey. We divide galaxies with a detected Hα emission line and coverage of Hβ into eight groups by stellar mass, star formation rate (SFR), and inclination (i.e., axis ratio), and we then stack their spectra. From each stack, we measure the Balmer decrement and gas-phase metallicity, and then we compute the median AV and UV continuum spectral slope (β). First, we find that none of the dust properties (Balmer decrement, AV , or β) varies with the axis ratio. Second, both stellar and nebular attenuation increase with increasing galaxy mass, showing little residual dependence on SFR or metallicity. Third, nebular emission is more attenuated than stellar emission, and this difference grows even larger at higher galaxy masses and SFRs. Based on these results, we propose a three-component dust model in which attenuation predominantly occurs in star-forming regions and large, dusty star-forming clumps, with minimal attenuation in the diffuse ISM. In this model, nebular attenuation primarily originates in clumps, while stellar attenuation is dominated by star-forming regions. Clumps become larger and more common with increasing galaxy mass, creating the above mass trends. Finally, we argue that a fixed metal yield naturally leads to mass regulating dust attenuation. Infall of low-metallicity gas increases the SFR and lowers the metallicity, but leaves the dust column density mostly unchanged. We quantify this idea using the Kennicutt–Schmidt and fundamental metallicity relations, showing that galaxy mass is indeed the primary driver of dust attenuation.

A Preview Of Jwst Metallicity Studies At Cosmic Noon: The First Detection Of Auroral [O Ii] Emission At High Redshift, Ryan L. Sanders, Alice E. Shapley, Leonardo Clarke, Michael W. Topping, Naveen Reddy, Mariska Kriek, Tucker Jones, Daniel P. Stark, Mengtao Tang

Physics and Astronomy Faculty Publications

We present ultradeep Keck/MOSFIRE rest-optical spectra of two star-forming galaxies at z = 2.18 in the COSMOS field with bright emission lines, representing more than 20 hr of total integration. The fidelity of these spectra enabled the detection of more than 20 unique emission lines for each galaxy, including the first detection of the auroral [O II]λλ7322, 7332 lines at high redshift. We use these measurements to calculate the electron temperature in the low-ionization O+ zone of the ionized interstellar medium and derive abundance ratios of O/H, N/H, and N/O using the direct method. The N/O and α/Fe abundance patterns …

Early Results From Glass–Jwst. Xxi. Rapid Asembly Of A Galaxy At Z = 6.23 Revealed By Its C/O Abundance, Tucker Jones, Ryan L. Sanders, Yuguang Chen, Xin Wang, Takahiro Morishita, Guido Roberts-Borsani, Tommaso Treu, Alan Dressler, Emiliano Merlin, Diego Paris, Paola Santini, Pietro Bergamini, A. Henry, Erin Huntzinger, Themiya Nanayakkara, Kristan Boyett, Marusa Bradac, Gabriel B. Brammer, Antonello Calabró, Karl Glazebrook, Kathryn Grasha, Sara Mascia, Laura Pentericci, Michele Trenti, Benedetta Vulcani

Physics and Astronomy Faculty Publications

The abundance of carbon relative to oxygen (C/O) is a promising probe of star formation history in the early universe, as the ratio changes with time due to production of these elements by different nucleosynthesis pathways. We present a measurement of log ( C / O ) = − 1.01 ± 0.12 (stat) ±0.15 (sys) in a z = 6.23 galaxy observed as part of the GLASS-JWST Early Release Science Program. Notably, we achieve good precision thanks to the detection of the rest-frame ultraviolet O iii], C iii], and C iv emission lines delivered by JWST/NIRSpec. The C/O abundance is …

Co Emission, Molecular Gas, And Metallicity In Main-Sequence Star-Forming Galaxies At Z ∼ 2.3, Ryan L. Sanders, Alice E. Shapley, Tucker Jones, Irene Shivaei, Gergö Popping, Naveen Reddy, Romeel Davé, Sedona H. Price, Bahram Mobasher, Mariska Kriek, Alison L. Coil, Brian Siana

Physics and Astronomy Faculty Publications

We present observations of CO(3−2) in 13 main-sequence z = 2.0-2.5 star-forming galaxies at log ( M * / M ⊙ ) = 10.2 - 10.6 that span a wide range in metallicity (O/H) based on rest-optical spectroscopy. We find that L CO ( 3 − 2 ) ′ /SFR decreases with decreasing metallicity, implying that the CO luminosity per unit gas mass is lower in low-metallicity galaxies at z ∼ 2. We constrain the CO-to-H₂ conversion factor (α _CO) and find that α _CO inversely correlates with metallicity at z ∼ 2. We derive molecular gas masses …

The Art Of Measuring Physical Parameters In Galaxies: A Critical Assessment Of Spectral Energy Distribution Fitting Techniques, Camilla Pacifici, Kartheik G. Iyer, Bahram Mobasher, Elisabete Da Cunha, Viviana Acquaviva, Denis Burgarella, Gabriela Calistro Rivera, Adam C. Carnall, Yu-Yen Chang, Nima Chartab, Kevin C. Cooke, Ciaran Fairhurst, Jeyhan Kartaltepe, Joel Leja, Katarzyna Małek, Brett Salmon, Marianna Torelli, Alba Vidal-García, Médéric Boquien, Gabriel B. Brammer, Michael J. I. Brown, Peter L. Capak, Jacopo Chevallard, Chiara Circosta, Darren Croton, Iary Davidzon, Mark Dickinson, Kenneth J. Duncan, Sandra M. Faber, Harry C. Ferguson, Adriano Fontana, Yicheng Guo, Boris Haeussler, Shoubaneh Hemmati, Marziye Jafariyazani, Susan A. Kassin, Rebecca L. Larson, Bomee Lee, Kameswara Bharadwaj Mantha, Francesca Marchi, Hooshang Nayyeri, Jeffrey A. Newman, Viraj Pandya, Janine Pforr, Naveen Reddy, Ryan L. Sanders, Ekta Shah, Abtin Shahidi, Matthew L. Stevans, Dian Puspita Triani, Krystal D. Tyler, Brittany N. Vanderhoof, Alexander De La Vega, Weichen Wang, Madalyn E. Weston

Physics and Astronomy Faculty Publications

The study of galaxy evolution hinges on our ability to interpret multiwavelength galaxy observations in terms of their physical properties. To do this, we rely on spectral energy distribution (SED) models, which allow us to infer physical parameters from spectrophotometric data. In recent years, thanks to wide and deep multiwave band galaxy surveys, the volume of high-quality data have significantly increased. Alongside the increased data, algorithms performing SED fitting have improved, including better modeling prescriptions, newer templates, and more extensive sampling in wavelength space. We present a comprehensive analysis of different SED-fitting codes including their methods and output with the …

The Dust-To-Gas Mass Ratio Of Luminous Galaxies As A Function Of Their Metallicity At Cosmic Noon, Gergö Popping, Irene Shivaei, Ryan L. Sanders, Tucker Jones, Alexandra Pope, Naveen Reddy, Alice E. Shapley, Alison L. Coil, Mariska Kriek

Physics and Astronomy Faculty Publications

Aims. We aim to quantify the relation between the dust-to-gas mass ratio (DTG) and gas-phase metallicity of z = 2.1-2.5 luminous galaxies and contrast this high-redshift relation against analogous constraints at z = 0.

Methods. We present a sample of ten star-forming main-sequence galaxies in the redshift range 2.1 < z < 2.5 with rest-optical emission-line information available from the MOSDEF survey and with ALMA 1.2 millimetre and CO J = 3-2 follow-up observations. The galaxies have stellar masses ranging from 1010.3 to 1010.6 M? and cover a range in star-formation rate from 35 to 145 M? yr-1. We calculated the gas-phase oxygen abundance of these galaxies from rest-optical nebular emission lines (8.4 < 12+log (O=H) < 8.8, corresponding to 0.5..1.25 Z?). We estimated the dust and H2 masses of the galaxies (using a metallicity-dependent CO-to-H2 conversion factor) from the 1.2mm and CO J = 3..2 observations, respectively, from which we estimated a DTG.

Results. We find that the galaxies in this sample follow the trends already observed between CO line luminosity and dust-continuum luminosity from z = 0 to z = 3, extending such trends to fainter galaxies at 2.1 < z < 2.5 than observed to date. We find no second-order metallicity dependence in the CO - dust-continuum luminosity relation for the galaxies presented in this work. The DTGs of main-sequence galaxies at 2.1 < z < 2.5 are consistent with an increase in the DTG with gas-phase metallicity. The metallicity dependence of the DTG is driven by the metallicity dependence of the CO-to-H2 conversion factor. Galaxies at z = 2.1-2.5 are furthermore consistent with the DTG-metallicity relation found at z = 0 (i.e. with no significant evolution), providing relevant constraints for galaxy formation models. These results furthermore imply that the metallicity of galaxies should be taken into account when estimating cold-gas masses from dust-continuum emission, which is especially relevant when studying metal-poor low-mass or high-redshift galaxies.

Resolved Velocity Profiles Of Galactic Winds At Cosmic Noon, Keerthi Vasan G. C., Tucker Jones, Ryan L. Sanders, Richard S. Ellis, Daniel P. Stark, Glenn G. Kacprzak, Tania M. Barone, Kim-Vy H. Tran, Karl Glazebrook, Colin Jacobs

Physics and Astronomy Faculty Publications

We study the kinematics of the interstellar medium (ISM) viewed “down the barrel” in 20 gravitationally lensed galaxies during cosmic noon (z = 1.5-3.5). We use moderate-resolution spectra (R ∼ 4000) from Keck’s Echellette Spectrograph and Imager and Magellan/MagE to spectrally resolve the ISM absorption in these galaxies into ∼10 independent elements and use double Gaussian fits to quantify the velocity structure of the gas. We find that the bulk motion of gas in this galaxy sample is outflowing, with average velocity centroid v cent = − 141 km s⁻¹ (±111 km s⁻¹ scatter) measured with respect to …

The Mosdef-Lris Survey: Detection Of Inflowing Gas Towards Three Star-Forming Galaxies At Z ∼ 2, Andrew Weldon, Naveen Reddy, Michael W. Topping, Alice E. Shapley, Xinnan Du, Sedona H. Price, Ryan L. Sanders, Alison L. Coil, Bahram Mobasher, Mariska Kriek, Brian Siana, Saeed Rezaee

Physics and Astronomy Faculty Publications

We report on the discovery of cool gas inflows towards three star-forming galaxies at ∼ 2.30. Analysis of Keck Low-Resolution Imaging Spectrometer spectroscopy reveals redshifted low-ionization interstellar (LIS) metal absorption lines with centroid velocities of 60–130 km s⁻¹. These inflows represent some of the most robust detections of inflowing gas into isolated, star-forming galaxies at high redshift. Our analysis suggests that the inflows are due to recycling metal-enriched gas from previous ejections. Comparisons between the galaxies with inflows and a larger parent sample of 131 objects indicate that galaxies with detected inflows may have higher specific star formation …

The Impact Of Star-Formation-Rate Surface Density On The Electron Density And Ionization Parameter Of High-Redshift Galaxies, Naveen Reddy, Ryan L. Sanders, Alice E. Shapley, Michael W. Topping, Mariska Kriek, Alison L. Coil, Bahram Mobasher, Brian Siana, Saeed Rezaee

Physics and Astronomy Faculty Publications

We use the large spectroscopic data set of the MOSFIRE Deep Evolution Field survey to investigate some of the key factors responsible for the elevated ionization parameters (U) inferred for high-redshift galaxies, focusing in particular on the role of star-formation-rate surface density (Σ_SFR). Using a sample of 317 galaxies with spectroscopic redshifts z _spec ≃ 1.9-3.7, we construct composite rest-frame optical spectra in bins of Σ_SFR and infer electron densities, n _e, using the ratio of the [O ii] λ λ3727, 3730 doublet. Our analysis suggests a significant (≃3σ) correlation between n _e and Σ_{SFR …}

Beam Energy Dependence Of The Linear And Mode-Coupled Flow Harmonics In Au+Au Collisions, Star Collaboration

Physics and Astronomy Faculty Publications

The linear and mode-coupled contributions to higher-order anisotropic flow are presented for Au+Au collisions at √sNN = 27, 39, 54.4, and 200 GeV and compared to similar measurements for Pb+Pb collisions at the Large Hadron Collider (LHC). The coefficients and the flow harmonics’ correlations, which characterize the linear and mode-coupled response to the lower-order anisotropies, indicate a beam energy dependence consistent with an influence from the specific shear viscosity (η /s). In contrast, the dimensionless coefficients, mode-coupled response coefficients, and normalized symmetric cumulants are approximately beam-energy independent, consistent with a significant role from initial- state effects. These measurements could provide …

Energy Dependence Of Intermittency For Charged Hadrons In Au+Au Collisions At Rhic, The Star Collaboration

Physics and Astronomy Faculty Publications

Density fluctuations near the QCD critical point can be probed via an intermittency analysis in relativistic heavy-ion collisions. We report the first measurement of intermittency in Au+Au collisions at √sNN = 7.7-200 GeV measured by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The scaled factorial moments of identified charged hadrons are analyzed at mid-rapidity and within the transverse momentum phase space. We observe a power-law behavior of scaled factorial moments in Au+Au collisions and a decrease in the extracted scaling exponent (ν) from peripheral to central collisions. The ν is consistent with a constant for different collisions …

Global Polarization Of Λ And Λ¯ Hyperons In Au+Au Collisions At √S Nn = 19.6 And 27 Gev, Star Collaboration

Physics and Astronomy Faculty Publications

In relativistic heavy-ion collisions, a global spin polarization, PH, of Λ and Λ¯ hyperons along the direction of the system angular momentum was discovered and measured across a broad range of collision energies and demonstrated a trend of increasing PH with decreasing √sNN. A splitting between Λ and Λ¯ polarization may be possible due to their different magnetic moments in a late-stage magnetic field sustained by the quark-gluon plasma which is formed in the collision. The results presented in this study find no significant splitting at the collision energies of √sNN=19.6 and 27 GeV in the BNL Relativistic Heavy Ion …

Measurements Of Dielectron Production In Au + Au Collisions At √Snn = 27, 39, And 62.4 Gev From The Star Experiment, Star Collaboration

Physics and Astronomy Faculty Publications

We report systematic measurements of dielectron (e+e−) invariant-mass Mee spectra at midrapidity in Au + Au collisions at √s NN = 27, 39, and 62.4 GeV taken with the STAR detector at the Relativistic Heavy Ion Collider. For all energies studied, a significant excess yield of dielectrons is observed in the low-mass region (0.40 < M ee < 0.75 MeV/c2 ) compared to hadronic cocktail simulations at freeze-out. Models that include an in-medium broadening of the ρ-meson spectral function consistently describe the observed excess. In addition, we report acceptance-corrected dielectron-excess spectra for Au + Au collisions at midrapidity (|yee| < 1) in the 0–80% centrality bin for each collision energy. The integrated excess yields for 0.4 < Mee < 0.75 GeV/c2 , normalized by the charged particle multiplicity at midrapidity, are compared with previously published measurements for Au + Au at √s NN = 19.6 and 200 GeV. Models that include an in-medium broadening of the ρ-meson spectral function consistently describe the observed excess. The normalized excess yields in the low-mass region show no significant collision energy dependence. The data, however, are consistent with model calculations that demonstrate a modest energy dependence.

Measurements Of The Elliptic And Triangular Azimuthal Anisotropies In Central 3he + Au, D + Au And P + Au Collisions At √Snn P = 200 Gev, Star Collaboration

Physics and Astronomy Faculty Publications

The elliptic (v2) and triangular (v3) azimuthal anisotropy coefficients in central He3+Au, d+Au, and p+Au collisions at sNN=200 GeV are measured as a function of transverse momentum (pT) at midrapidity (|η|< 0.9), via the azimuthal angular correlation between two particles both at |η|< 0.9. While the v2(pT) values depend on the colliding systems, the v3(pT) values are system independent within the uncertainties, suggesting an influence on eccentricity from subnucleonic fluctuations in these small-sized systems. These results also provide stringent constraints for the hydrodynamic modeling of these systems.

K∗0 Production In Au + Au Collisions At √Snn = 7.7, 11.5, 14.5, 19.6, 27, And 39 Gev From The Rhic Beam Energy Scan, Star Collaboration

Physics and Astronomy Faculty Publications

We report the measurement of K∗0 meson at midrapidity (|y| < 1.0) in Au + Au collisions at √sNN = 7.7, 11.5, 14.5, 19.6, 27, and 39 GeV collected by the STAR experiment during the Relativistic Heavy Ion Collider (RHIC) beam energy scan program. The transverse momentum spectra, yield, and average transverse momentum of K∗0 are presented as functions of collision centrality and beam energy. The K∗0/K yield ratios are presented for different collision centrality intervals and beam energies. The K∗0/K ratio in heavy-ion collisions are observed to be smaller than that in small-system collisions (e + e and p + p). The K∗0/K ratio follows a similar centrality dependence to that observed in previous RHIC and Large Hadron Collider measurements. The data favor the scenario of the dominance of hadronic rescattering over regeneration for K∗0 production in the hadronic phase of the medium.

Observation Of Directed Flow Of Hypernuclei 3/Λ H And 4/Λ H In √𝑠nn=3  Gev Au+Au Collisions At Rhic, Star Collaboration

Physics and Astronomy Faculty Publications

We report here the first observation of directed flow (v1) of the hypernuclei H/Λ 3 and H/Λ 4 in mid-central Au+Au collisions at √sNN=3 GeV at RHIC. These data are taken as part of the beam energy scan program carried out by the STAR experiment. From 165×106 events in 5%-40% centrality, about 8400 H/Λ 3 and 5200 H/Λ 4 candidates are reconstructed through two- and three-body decay channels. We observe that these hypernuclei exhibit significant directed flow. Comparing to that of light nuclei, it is found that the midrapidity v1 slopes of H/Λ 3 and H/Λ 4 follow baryon number …

Pion, Kaon, And (Anti)Proton Production In U+U Collisions At √Snn = 193 Gev Measured With The Star Detector, Star Collaboration

Physics and Astronomy Faculty Publications

We present the first measurements of transverse momentum spectra of π±, K±, p( ¯p) at midrapidity (|y| < 0.1) in U+U collisions at √s NN = 193 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The centrality dependence of particle yields, average transverse momenta, particle ratios and kinetic freeze-out parameters are discussed. The results are compared with the published results from Au+Au collisions at √s NN = 200 GeV in STAR. The results are also compared to those from A Multi-Phase Transport ( AMPT) model.

Search For The Chiral Magnetic Effect In Au+Au Collisions At √Snn = 27 Gev With The Star Forward Event Plane Detectors, Star Collaboration

Physics and Astronomy Faculty Publications

A decisive experimental test of the Chiral Magnetic Effect (CME) is considered one of the major scientific goals at the Relativistic Heavy-Ion Collider (RHIC) towards understanding the nontrivial topological fluctuations of the Quantum Chromodynamics vacuum. In heavy-ion collisions, the CME is expected to result in a charge separation phenomenon across the reaction plane, whose strength could be strongly energy dependent. The previous CME searches have been focused on top RHIC energy collisions. In this Letter, we present a low energy search for the CME in Au+Au collisions at √sNN = 27 GeV. We measure elliptic flow scaled charge-dependent correlators relative …

Search For The Chiral Magnetic Wave Using Anisotropic Flow Of Identified Particles At Energies Available At The Bnl Relativistic Heavy Ion Collider, Star Collaboration

Physics and Astronomy Faculty Publications

The chiral magnetic wave (CMW) has been theorized to propagate in the deconfined nuclear medium formed in high-energy heavy-ion collisions and to cause a difference in elliptic flow (𝑣2) between negatively and positively charged hadrons. Experimental data consistent with the CMW have been reported by the STAR Collaboration at the Relativistic Heavy Ion Collider (RHIC), based on the charge asymmetry dependence of the pion 𝑣2 from Au +Au collisions at √𝑠𝑁⁢𝑁=27 to 200 GeV. In this comprehensive study, we present the STAR measurements of elliptic flow and triangular flow of charged pions, along with the 𝑣2 of charged kaons and …