Publications

Order by: publication date number of citations

• Topological photonic band gaps in honeycomb atomic arrays

  Pierre Wulles, Sergey E. Skipetrov

  SciPost Phys. Core 7, 051 (2024) · published 7 August 2024 | Toggle abstract · pdf

  lattice of two-level atoms coupled by the in-plane electromagnetic field may exhibit band gaps that can be opened either by applying an external magnetic field or by breaking the symmetry between the two triangular sublattices of which the honeycomb one is a superposition. We establish the conditions of band gap opening, compute the width of the gap, and characterize its topological property by a topological index (Chern number). The topological nature of the band gap leads to inversion of the population imbalance between the two triangular sublattices for modes with frequencies near band edges. It also prohibits a transition to the trivial limit of infinitely spaced, noninteracting atoms without closing the spectral gap. Surrounding the lattice by a Fabry-Pérot cavity with small intermirror spacing $d < \pi/k_0$, where $k_0$ is the free-space wave number at the atomic resonance frequency, renders the system Hermitian by suppressing the leakage of energy out of the atomic plane without modifying its topological properties. In contrast, a larger $d$ allows for propagating optical modes that are built up due to reflections at the cavity mirrors and have frequencies inside the band gap of the free-standing lattice, thus closing the latter.

  1 citation

• Exact first-order effect of interactions on the ground-state energy of harmonically-confined fermions

  Pierre Le Doussal, Naftali R. Smith, Nathan Argaman

  SciPost Phys. 17, 038 (2024) · published 7 August 2024 | Toggle abstract · pdf

  We consider a system of $N$ spinless fermions, interacting with each other via a power-law interaction $\epsilon/r^n$, and trapped in an external harmonic potential $V(r) = r^2/2$, in $d=1,2,3$ dimensions. For any $0 < n < d+2$, we obtain the ground-state energy $E_N$ of the system perturbatively in $\epsilon$, $E_{N}=E_{N}^{(0)}+\epsilon E_{N}^{(1)}+O(\epsilon^{2})$. We calculate $E_{N}^{(1)}$ exactly, assuming that $N$ is such that the "outer shell" is filled. For the case of $n=1$ (corresponding to a Coulomb interaction for $d=3$), we extract the $N \gg 1$ behavior of $E_{N}^{(1)}$, focusing on the corrections to the exchange term with respect to the leading-order term that is predicted from the local density approximation applied to the Thomas-Fermi approximate density distribution. The leading correction contains a logarithmic divergence, and is of particular importance in the context of density functional theory. We also study the effect of the interactions on the fermions' spatial density. Finally, we find that our result for $E_{N}^{(1)}$ significantly simplifies in the case where $n$ is even.

  1 citation

• Measurement of 3He analyzing power for p-3He scattering using the polarized 3He target

  A. Watanabe, S. Nakai, K. Sekiguchi, T. Akieda, D. Etoh, M. Inoue, Y. Inoue, K. Kawahara, H. Kon, K. Miki, T. Mukai, D. Sakai, S. Shibuya, Y. Shiokawa, T. Taguchi, H. Umetsu, Y. Utsuki, Y. Wada, M. Watanabe, M. Itoh, T. Ino, T. Wakui, K. Hatanaka, H. Kanda, H. J. Ong, D. T. Tran, S. Goto, Y. Hirai, D. Inomoto, H. Kasahara, S. Mitsumoto, H. Oshiro, T. Wakasa, Y. Maeda, K. Nonaka, H. Sakai, T. Uesaka

  SciPost Phys. Proc. 3, 020 (2020) · published 25 February 2020 | Toggle abstract · pdf

  Proton–3He scattering is one of the good probes to study the T = 3/2 channel of three– nucleon forces. We have measured 3He analyzing powers for p−3He elastic scattering with the polarized 3He target at 70 and 100 MeV. In the conference the data were com- pared with the theoretical predictions based on the modern nucleon–nucleon potentials. Large discrepancies were found between the data and the calculations at the angles where the 3He analyzing power takes the minimum and maximum values.

  1 citation

• Search for low mass WIMP dark matter with DarkSide-50

  Masato Kimura on behalf of DarkSide-50 Collaboration

  SciPost Phys. Proc. 12, 022 (2023) · published 3 July 2023 | Toggle abstract · pdf

  DarkSide-50 is a direct dark matter detection experiment at Laboratori Nazionali del Gran Sasso that uses argon as the target material. Exploiting the ionization signal from a dual-phase time projection chamber filled with low-radioactivity argon, it has set the most stringent exclusion limit on WIMPs with a mass of few $\mathrm{GeV}/c^2$. A new analysis has recently been carried out with a larger exposure, profiting from an improved understanding of the detector response and background model. An improvement of about a factor 10 in sensitivity is expected for a WIMP mass of 2 GeV/c$^2$.

  1 citation

• Higgs production via vector-boson fusion at the LHC

  Gaetano Barone, Jiayi Chen, Stephane Cooperstein, Nikita Dolganov, Silvia Ferrario Ravasio, Yacine Haddad, Stefan Höche, Barbara Jäger, Alexander Karlberg, Alexander Mück, Mathieu Pellen, Christian T. Preuss, Daniel Reichelt, Simon Reinhardt, Marco Zaro

  SciPost Phys. Comm. Rep. 13 (2025) · published 5 November 2025 | Toggle abstract · pdf

  In this article, we summarise the recent experimental measurements and theoretical work on Higgs boson production via vector-boson fusion at the LHC. Along with this, we provide state-of-the-art predictions at fixed order as well as with parton-shower corrections within the Standard Model at $13.6\,\text{TeV}$. The results are presented in the form of multi-differential distributions as well as in the Simplified Template Cross Section bins. All materials and outputs of this study are available on public repositories. Finally, following findings in the literature, recommendations are made to estimate theoretical uncertainties related to parton-shower corrections.

  1 citation

• Next-to-leading power SCET in Higgs amplitudes induced by light quarks

  Xing Wang

  SciPost Phys. Proc. 7, 040 (2022) · published 22 June 2022 | Toggle abstract · pdf

  In this article, we report how to use the "plus-type" subtraction scheme to deal with endpoint divergences in $h\rightarrow\gamma\gamma$ or $gg\rightarrow h$ amplitudes induced by light quark loop, which can be formulated by next-to-leading power (NLP) SCET. This subtraction is ensured by two re-factorization conditions, which have been proven to all orders in $\alpha_s$. Based on these conditions, cutoffs emerge naturally after some re-arrangements to handle endpoint divergences and renormalization is compatible with that. Our formalism can analytically reproduce three-loop amplitudes up to $\ln^3(-M_h^2/m_b^2-i0)$ and resum to next-to-leading logarithm and beyond.

  1 citation

• Measurement for p–3He elastic scattering with a 65 MeV polarized proton beam

  S. Nakai, K. Sekiguchi, K. Miki, A. Watanabe, S. Shibuya, M. Watanabe, K. Kawahara, D. Sakai, Y. Wada, H. Umetsu, M. Itoh, K. Hatanaka, A. Tamii, N. Kobayashi, A. Inoue, S. Nakamura, T. Wakasa, S. Mitsumoto, H. Ohshiro, S. Goto, Y. Maeda, H. Sakai

  SciPost Phys. Proc. 3, 019 (2020) · published 25 February 2020 | Toggle abstract · pdf

  We measured the cross section and the proton analyzing power Ay for p–3He elastic scattering at the angles θ = 26.9◦–170.1◦ in the center of mass system with a 65 MeV polarized proton beam. We compared the data with the rigorous numerical calculations based on the various nucleon–nucleon potentials. For the cross section, clear discrepancy is seen at the angles where the cross section takes minimum. For the proton analyzing power Ay, the calculations have moderate agreements to the data. In this proceedings, we show only the experimental results.

  1 citation

• Magic phase transition and non-local complexity in generalized W State

  Alberto Giuseppe Catalano, Jovan Odavić, Gianpaolo Torre, Alioscia Hamma, Fabio Franchini, Salvatore Marco Giampaolo

  SciPost Phys. Core 8, 078 (2025) · published 6 November 2025 | Toggle abstract · pdf

  We employ the Stabilizer Rényi Entropy (SRE) to characterize a quantum phase transition that has so far eluded any standard description and can thus now be explained in terms of the interplay between its non-stabilizer properties and entanglement. The transition under consideration separates a region with a unique ground state from one with a degenerate ground state manifold spanned by states with finite and opposite (intensive) momenta. We show that SRE has a jump at the crossing points, while the entanglement entropy remains continuous. Moreover, by leveraging a Clifford circuit mapping, we connect the observed jump in SRE to that occurring between standard and generalized $W$-states with finite momenta. This mapping allows us to quantify the SRE discontinuity analytically.

  1 citation

• EUSO-SPB2: A sub-orbital cosmic ray and neutrino multi-messenger pathfinder observatory

  Austin Cummings, Johannes Eser, George Filippatos, Angela V. Olinto, Tonia M. Venters, Lawrence Wiencke for the JEM-EUSO collaboration

  SciPost Phys. Proc. 13, 038 (2023) · published 29 September 2023 | Toggle abstract · pdf

  The next generation of ultra-high energy cosmic ray (UHECR) and very-high energy neutrino observatories will address the challenge of the extremely low fluxes of these particles at the highest energies. EUSO-SPB2 (Extreme Universe Space Observatory on a Super Pressure Balloon 2) is designed to prepare space missions to address this challenge. EUSO-SPB2 is equipped with 2 telescopes: the Fluorescence Telescope, which will point downwards and measure fluorescence emission from UHECR air showers with an energy above 2 EeV, and the Cherenkov Telescope (CT), which will point towards the Earth's limb and measure direct Cherenkov emission from cosmic rays with energies above 1 PeV verifying the technique. Pointed below the limb, the CT will search for Cherenkov emission produced by neutrino-sourced tau-lepton decays above 10 PeV energies and study backgrounds for such events. The EUSO-SPB2 mission will provide pioneering observations and technical milestones on the path towards a space-based multi-messenger observatory.

  1 citation

• Reduction in radioactivity-induced backgrounds using a novel active veto detector for rare event search experiments

  Mouli Chaudhuri, Andrew Jastram, Glenn Agnolet, Samir Banik, Hao Chen, Vijay Iyer, Varchaswi K. S. Kashyap, Andrew Kubik, Matthew Lee, Rupak Mahapatra, Sandro Maludze, Nader Mirabolfathi, Nityasa Mishra, Bedangadas Mohanty, Himangshu Neog, Mark Platt

  SciPost Phys. Proc. 12, 017 (2023) · published 3 July 2023 | Toggle abstract · pdf

  The results of a newly developed annular cryogenic phonon-mediated active veto detector are discussed which shows a significant reduction of radioactivity-induced backgrounds in rare event search experiments. The veto detector is made up of germanium weighing $\sim$500 g with an outer diameter of 76 mm and an inner diameter of 28 mm. The detector can host a 25 mm diameter germanium inner target detector of mass $\sim$10 g. A GEANT4 simulation with the active veto and inner target detector shows a gamma background reduction of 50 - 80% which is further improved (> 90%) with 4$\pi$ veto coverage. Experimental measurements with the detector assembly agree well with the simulation.

  1 citation