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1. Probing Strangeness Hadronization with Event-by-Event Production of Multistrange Hadrons

   https://doi.org/10.1103/PhysRevLett.134.022303  

   Acharya, S; Adamová, D; Agarwal, A; Aglieri_Rinella, G; Aglietta, L; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahn, S U; et al (January 2025, Physical Review Letters)

   This Letter presents the first measurement of event-by-event fluctuations of the net number (difference between the particle and antiparticle multiplicities) of multistrange hadrons ${\mathrm{\Xi }}^{-}$and ${\overline{\mathrm{\Xi }}}^{+}$and its correlation with the net-kaon number using the data collected by the ALICE Collaboration in pp, p-Pb, and Pb-Pb collisions at a center-of-mass energy per nucleon pair $\sqrt{s_{\mathrm{NN}}}=5.02\mathrm{TeV}$. The statistical hadronization model with a correlation over three units of rapidity between hadrons having the same and opposite strangeness content successfully describes the results. On the other hand, string-fragmentation models that mainly correlate strange hadrons with opposite strange quark content over a small rapidity range fail to describe the data. © 2025 CERN, for the ALICE Collaboration2025CERN 

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2. Enantioselective One-Photon Excitation of Formic Acid

   https://doi.org/10.1103/PhysRevLett.133.093002  

   Tsitsonis, D; Trinter, F; Williams, J B; Fehre, K; Demekhin, Ph V; Jahnke, T; Dörner, R; Schöffler, M S (August 2024, Physical Review Letters)

   We use one-photon excitation to promote $K$-shell electrons of formic acid (which has a planar equilibrium structure) to an antibonding ${\pi }^{*}$orbital. The excited molecule is known to have a (chiral) pyramidal equilibrium structure. In our experiment, we determine the handedness of the excited molecule by imaging the momenta of charged fragments, which occur after its Coulomb explosion triggered by Auger-Meitner decay cascades succeeding the excitation. We find that the handedness of the excited molecule depends on its spatial orientation with respect to the propagation (or polarization) direction of the exciting photon. The effect is largely independent of the exact polarization properties of the light driving the $1s\to {\pi }^{*}$excitation. Published by the American Physical Society2024 

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3. Measuring the angular momentum of a neutron using Earth's rotation

   https://doi.org/10.1103/PhysRevResearch.7.013046  

   Geerits, Niels; Sponar, Stephan; Steffen, Kyle E; Snow, William M; Parnell, Steven R; Mauri, Giacomo; Smith, Gregory N; Dalgliesh, Robert M; de_Haan, Victor (January 2025, Physical Review Research)

   A coupling between Earth's rotation and orbital angular momentum (OAM), known as the Sagnac effect, is observed in entangled neutrons produced using a spin-echo interferometer. After correction for instrument systematics the measured coupling is within 5% of theory, with an uncertainty of 7.2%. The OAM in our setup is transverse to the propagation direction and scales linearly with neutron wavelength (4–12.75 Å), so the Sagnac coupling can be varied without mechanically rotating the device, which avoids systematic errors present in previous experiments. The detected transverse OAM of our beam corresponds to $4098\pm 295\hslash {\AA }^{-1},{10}^5$times lower than in the previous neutron experiments. This demonstrates the feasibility of using the Sagnac effect to definitively measure neutron OAM and paves the way towards a future observation of the quantum Sagnac effect. Published by the American Physical Society2025 

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4. Isotope-selective strong-field ionization of semiheavy water

   https://doi.org/10.1103/PhysRevResearch.7.L012062  

   Howard, A J; Britton, M; Streeter, Z L; Cheng, C; Lucchese, R R; McCurdy, C W; Bucksbaum, P H (March 2025, Physical Review Research)

   Semiheavy water (HOD) is one of the simplest molecules in which the bonds are labeled by isotope. We demonstrate that a pair of intense few-femtosecond infrared laser pulses can be used to selectively tunnel ionize along one of the two bonds. The first pulse doubly ionizes HOD, inducing rapid bond stretching and unbending. Femtoseconds later, the second pulse arrives and further ionization is selectively enhanced along the OH bond. These conclusions arise from 3D time-resolved measurements of ${\mathrm{H}}^{+}, {\mathrm{D}}^{+}$, and ${\mathrm{O}}^{+}$momenta following triple ionization. Published by the American Physical Society2025 

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5. Mechanical shear controls bacterial penetration in mucus

   https://doi.org/10.1038/s41598-019-46085-z  

   Figueroa-Morales, Nuris; Dominguez-Rubio, Leonardo; Ott, Troy L.; Aranson, Igor S. (July 2019, Scientific Reports)

   Abstract Mucus plays crucial roles in higher organisms, from aiding fertilization to protecting the female reproductive tract. Here, we investigate how anisotropic organization of mucus affects bacterial motility. We demonstrate by cryo electron micrographs and elongated tracer particles imaging, that mucus anisotropy and heterogeneity depend on how mechanical stress is applied. In shallow mucus films, we observe bacteria reversing their swimming direction without U-turns. During the forward motion, bacteria burrowed tunnels that last for several seconds and enable them to swim back faster, following the same track. We elucidate the physical mechanism of direction reversal by fluorescent visualization of the flagella: when the bacterial body is suddenly stopped by the mucus structure, the compression on the flagellar bundle causes buckling, disassembly and reorganization on the other side of the bacterium. Our results shed light into motility of bacteria in complex visco-elastic fluids and can provide clues in the propagation of bacteria-born diseases in mucus. 

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