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1. The polarization sensitivity of GRETINA

   https://doi.org/10.1016/j.nima.2021.166155  

   Morse, C.; Crawford, H.L.; Macchiavelli, A.O.; Wiens, A.; Albers, M.; Ayangeakaa, A.D.; Bender, P.C.; Campbell, C.M.; Carpenter, M.P.; Chowdhury, P.; et al (February 2022, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment)
2. Polarization of thermal dilepton radiation

   https://doi.org/10.1016/j.physletb.2025.139267  

   Seck, Florian; Friman, Bengt; Galatyuk, Tetyana; van_Hees, Hendrik; Rapp, Ralf; Speranza, Enrico; Wambach, Jochen (February 2025, Physics Letters B)

   The invariant mass spectra of dileptons radiated from the fireballs formed in high-energy heavy-ion collisions have been successfully used to investigate the properties of hot and dense QCD matter. Using a realistic model for the in-medium electromagnetic spectral function, we predict polarization observables and compare them to experiment. This allows, for the first time, independent tests of the longitudinal and transverse components of the virtual photon’s selfenergy. While the low- and high-mass regions exhibit the expected limits of transverse and unpolarized photons, respectively, baryon-driven medium effects in the 𝜌-meson mass region create a marked longitudinal polarization that transits into a largely unpolarized emission from the quark-gluon plasma, thus providing a sensitive test of microscopic emission processes in QCD matter. Applications to available data from the HADES and NA60 experiments at SIS and SPS energies, respectively, are consistent with our predictions and set the stage for quantitative polarization studies at FAIR and collider energies. 

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3. Whirls and swirls of polarization

   https://doi.org/10.1126/science.abg4477  

   Martin, Lane W. (March 2021, Science)

   null (Ed.)
4. Polarization Analysis of Enceladus’ Surface

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   Morello, Claudia D; West, Robert A; Berg, Matthew J (March 2025, Journal of Quantitative Spectroscopy and Radiative Transfer)
5. General Strong Polarization

   https://doi.org/10.1145/3491390  

   Błasiok, Jarosław; Guruswami, Venkatesan; Nakkiran, Preetum; Rudra, Atri; Sudan, Madhu (April 2022, Journal of the ACM)

   Arıkan’s exciting discovery of polar codes has provided an altogether new way to efficiently achieve Shannon capacity. Given a (constant-sized) invertible matrix M , a family of polar codes can be associated with this matrix and its ability to approach capacity follows from the polarization of an associated [0, 1]-bounded martingale, namely its convergence in the limit to either 0 or 1 with probability 1. Arıkan showed appropriate polarization of the martingale associated with the matrix ( G 2 = ( 1 1 0 1) to get capacity achieving codes. His analysis was later extended to all matrices M that satisfy an obvious necessary condition for polarization. While Arıkan’s theorem does not guarantee that the codes achieve capacity at small blocklengths (specifically in length, which is a polynomial in ( 1ε ) where (ε) is the difference between the capacity of a channel and the rate of the code), it turns out that a “strong” analysis of the polarization of the underlying martingale would lead to such constructions. Indeed for the martingale associated with ( G 2 ) such a strong polarization was shown in two independent works (Guruswami and Xia (IEEE IT’15) and Hassani et al. (IEEE IT’14)), thereby resolving a major theoretical challenge associated with the efficient attainment of Shannon capacity. In this work we extend the result above to cover martingales associated with all matrices that satisfy the necessary condition for (weak) polarization. In addition to being vastly more general, our proofs of strong polarization are (in our view) also much simpler and modular. Key to our proof is a notion of local polarization that only depends on the evolution of the martingale in a single time step. We show that local polarization always implies strong polarization. We then apply relatively simple reasoning about conditional entropies to prove local polarization in very general settings. Specifically, our result shows strong polarization over all prime fields and leads to efficient capacity-achieving source codes for compressing arbitrary i.i.d. sources, and capacity-achieving channel codes for arbitrary symmetric memoryless channels. We show how to use our analyses to achieve exponentially small error probabilities at lengths inverse polynomial in the gap to capacity. Indeed we show that we can essentially match any error probability while maintaining lengths that are only inverse polynomial in the gap to capacity. 

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