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1. Anisotropic flow of identified hadrons in Xe-Xe collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ = 5.44 TeV

   https://doi.org/10.1007/JHEP10(2021)152  

   Acharya, S.; Adamová, D.; Adler, A.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Ahuja, I.; et al (October 2021, Journal of High Energy Physics)

   A bstract Measurements of elliptic ( v 2 ) and triangular ( v 3 ) flow coefficients of π ± , K ± , p+ $$ \overline{\mathrm{p}} $$ p ¯ , $$ {\mathrm{K}}_{\mathrm{S}}^0 $$ K S 0 , and Λ+ $$ \overline{\Lambda} $$ Λ ¯ obtained with the scalar product method in Xe-Xe collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ s NN = 5 . 44 TeV are presented. The results are obtained in the rapidity range | y | < 0 . 5 and reported as a function of transverse momentum, p T , for several collision centrality classes. The flow coefficients exhibit a particle mass dependence for p T < 3 GeV/ c , while a grouping according to particle type (i.e., meson and baryon) is found at intermediate transverse momenta (3 < p T < 8 GeV/ c ). The magnitude of the baryon v 2 is larger than that of mesons up to p T = 6 GeV/ c . The centrality dependence of the shape evolution of the p T -differential v 2 is studied for the various hadron species. The v 2 coefficients of π ± , K ± , and p+ $$ \overline{\mathrm{p}} $$ p ¯ are reproduced by MUSIC hydrodynamic calculations coupled to a hadronic cascade model (UrQMD) for p T < 1 GeV/ c . A comparison with v n measurements in the corresponding centrality intervals in Pb-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ s NN = 5 . 02 TeV yields an enhanced v 2 in central collisions and diminished value in semicentral collisions. 

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2. P-V-T equation of state of boron carbide

   Somayazulu, M.; Ahart, M.; Meng, Y.; Ciezak, J.; Velisavlevic, N.; Hemley, R. J. (October 2023, Philosophical transactions A)

   We report the P-V-T equation of state measurements of B4C to 50GPa and approximately 2500K in laser-heated diamond anvil cells. We obtain an ambient temperature, third-order Birch–Murnaghan fit to the P-V data that yields a bulk modulus K0 of 221(2) GPa and derivative, (dK/dP)0 of 3.3(1). These were used in fits with both a Mie–Grüneisen– Debye model and a temperature-dependent, Birch– Murnaghan equation of state that includes thermal pressure estimated by thermal expansion (α) and a temperature-dependent bulk modulus (dK0/dT). The ambient pressure thermal expansion coefficient (α0+α1T), Grüneisen γ (V)=γ 0(V/V0)q and volumedependent Debye temperature, were used as input parameters for these fits and found to be sufficient to describe the data in the whole P-T range of this study. 

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3. The 'Signature' of Particle Geometry - DEM Modelling Perspective

   https://doi.org/10.23967/particles.2021.033  

   Lee, S.; Lee, C.; Shin, M.; Tripathi, P. (February 2022, PARTICLES 2021 – VII International Conference on Particle-based Methods, Hamburg, Germany, October 4-6, 2021)

   Wriggers, Peter; Bischoff, Manfred; Oñate, Eugenio; Düster, Alexander; Zohdi, Tarek (Ed.)

   This study evidences that the particle surface-area-to-volume ratio (A/V) and the particle volume (V) have the key information of particle geometry and the ‘signature’ is realized by a power-law relationship between A/V and V in a form of V = (A/V)^α × β. We find that the power value α is influenced by the shape-size relationship while the β* term (β evaluated with a fixed value of α = -3) informs the average particle shape of a granular material regarding the overall angularity. This study also discusses how the particle shape can be retrieved in terms of Wadell’s true sphericity using the A/V and V. This concept is linked to another shape index M that interprets the particle shape as a function of surface area A, volume V, and size L. This paper explains the analytical aspects of geometric ‘signature’ and examines the idea using the example particles to address the DEM modelling-related questions. 

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4. Joint Poisson distribution of prime factors in sets

   https://doi.org/10.1017/S0305004121000499  

   FORD, KEVIN (July 2022, Mathematical Proceedings of the Cambridge Philosophical Society)

   Abstarct Given disjoint subsets T 1 , …, T m of “not too large” primes up to x , we establish that for a random integer n drawn from [1, x ], the m -dimensional vector enumerating the number of prime factors of n from T 1 , …, T m converges to a vector of m independent Poisson random variables. We give a specific rate of convergence using the Kubilius model of prime factors. We also show a universal upper bound of Poisson type when T 1 , …, T m are unrestricted, and apply this to the distribution of the number of prime factors from a set T conditional on n having k total prime factors. 

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5. INFERNO: Galactic winds in dwarf galaxies with star-by-star simulations including runaway stars

   https://doi.org/10.1093/mnras/stad692  

   Andersson, Eric P.; Agertz, Oscar; Renaud, Florent; Teyssier, Romain (March 2023, Monthly Notices of the Royal Astronomical Society)

   ABSTRACT The formation and evolution of galaxies have proved sensitive to the inclusion of stellar feedback, which is therefore crucial to any successful galaxy model. We present INFERNO, a new model for hydrodynamic simulations of galaxies, which incorporates resolved stellar objects with star-by-star calculations of when and where the injection of enriched material, momentum, and energy takes place. INFERNO treats early stellar kinematics to include phenomena such as walkaway and runaway stars. We employ this innovative model on simulations of a dwarf galaxy and demonstrate that our physically motivated stellar feedback model can drive vigorous galactic winds. This is quantified by mass and metal loading factors in the range of 10–100, and an energy loading factor close to unity. Outflows are established close to the disc, are highly multiphase, spanning almost 8 orders of magnitude in temperature, and with a clear dichotomy between mass ejected in cold, slow-moving (T ≲ 5 × 104 K, v < 100 km s−1) gas and energy ejected in hot, fast-moving (T > 106 K, v > 100 km s−1) gas. In contrast to massive disc galaxies, we find a surprisingly weak impact of the early stellar kinematics, with runaway stars having little to no effect on our results, despite exploding in diffuse gas outside the dense star-forming gas, as well as outside the galactic disc entirely. We demonstrate that this weak impact in dwarf galaxies stems from a combination of strong feedback and a porous interstellar medium, which obscure any unique signatures that runaway stars provide. 

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