Publications

Order by: publication date number of citations

• Impact of uncertainties of unbound 10Li on the ground state of two-neutron halo 11Li

  Jagjit Singh, Wataru Horiuchi

  SciPost Phys. Proc. 3, 007 (2020) · published 24 February 2020 | Toggle abstract · pdf

  Recently, the energy spectrum of 10Li was measured upto 4.6 MeV, via one-neutron transfer reaction d(9Li, p)10Li. Considering the ambiguities on the 10Li continuum spectrum with reference to new data, we report the con guration mixing in the ground state of the two-neutron halo nucleus 11Li for two different choices of the 9Li+n potential. For the present study, we employ a three-body (core+n+n) structure model developed for describing the two-neutron halo system by explicit coupling of unbound continuum states of the subsystem (core+n), and discuss the two-neutron correlations in the ground state of 11Li.

• All order merging of high energy and soft collinear resummation

  Jeppe R. Andersen, Hitham Hassan, Sebastian Jaskiewicz

  SciPost Phys. Proc. 15, 022 (2024) · published 3 April 2024 | Toggle abstract · pdf

  We present a method of merging the exclusive LO-matched high energy resummation of High Energy Jets (HEJ) with the parton shower of PYTHIA which preserves the accuracy of the LO cross sections and the logarithmic accuracy of both resummation schemes across all of phase space. Predictions produced with this merging prescription are presented with comparisons to data from experimental studies and suggestions are made for further observables and experimental cuts which highlight the importance of both high energy and soft-collinear effects.

• Muon measurements at the Pierre Auger Observatory

  Dariusz Góra

  SciPost Phys. Proc. 15, 020 (2024) · published 3 April 2024 | Toggle abstract · pdf

  The Pierre Auger Observatory is the world's largest detector for observation of ultra-high-energy cosmic rays (UHECRs) (above the energy of $10^{17}$ eV). It consists of a Fluorescence Detector (FD) and an array of particle detectors known as the Surface Detector (SD). Observations of extensive air showers by the Observatory can be used to probe hadronic interactions at high energy, in a kinematic and energy region inaccessible to experiments at man-made accelerators and to measure the muon component of the shower. Air showers induced by different primaries have different muon contents. With increasing mass of the primary cosmic ray particle, it is expected that the muon content in the corresponding air showers should also increase. Therefore, the determination of the muon component in the air shower is crucial to infer the mass of the primary particle. This is a key ingredient in the searches conducted to pinpoint the sources of UHECRs. Recent results obtained from the Pierre Auger Observatory and other experiments indicate that all the shower simulations underestimate the number of muons in the showers compared to the data. This is the so-called muon deficit. In this paper we briefly review the muon measurements, and present in more detail recent results on fluctuations in the muon number. These results provide new insights into the origin of the muon deficit in air shower simulations and constrain the models of hadronic interactions at ultrahigh energies. With the current design of the surface detectors it is also difficult to reliably separate the contributions of muons to the SD signal from the contributions of photons, electrons, and positrons. Therefore, we also present a new method to extract the muon component of the signal time traces recorded by each SD station using recurrent neural networks. The combination of such algorithms, with the future data collected by the upgraded Pierre Auger Observatory, will be a major step forward, as we are likely to achieve an unprecedented resolution in mass estimation on an event-by-event basis.

• Integrable deformations of superintegrable quantum circuits

  Tamás Gombor, Balázs Pozsgay

  SciPost Phys. 16, 114 (2024) · published 26 April 2024 | Toggle abstract · pdf

  Superintegrable models are very special dynamical systems: they possess more conservation laws than what is necessary for integrability. This severely constrains their dynamical processes, and it often leads to their exact solvability, even in non-equilibrium situations. In this paper we consider special Hamiltonian deformations of superintegrable quantum circuits. The deformations break superintegrability, but they preserve integrability. We focus on a selection of concrete models and show that for each model there is an (at least) one parameter family of integrable deformations. Our most interesting example is the so-called Rule54 model. We show that the model is compatible with a one parameter family of Yang-Baxter integrable spin chains with six-site interaction. Therefore, the Rule54 model does not have a unique integrability structure, instead it lies at the intersection of a family of quantum integrable models.

• Photon pumping, photodissociation and dissipation at interplay for the fluorescence of a molecule in a cavity

  Megha Gopalakrishna, Emil Viñas Boström, Claudio Verdozzi

  SciPost Phys. 15, 138 (2023) · published 5 October 2023 | Toggle abstract · pdf

  We introduce a model description of a diatomic molecule in an optical cavity, with pump and fluorescent fields, and electron and nuclear motion are treated on equal footing and exactly. The model accounts for several optical response temporal scenarios: A Mollow spectrum hindered by electron correlations, a competition of harmonic generation and molecular dissociation, a dependence of fluorescence on photon pumping rate and dissipation. It is thus a general and flexible template for insight into experiments where quantum photon confinement, leakage, nuclear motion and electronic correlations are at interplay.

• Study of charmonium(-like) spectroscopy and decay at BESIII

  Weimin Song, Honghong Zhang

  SciPost Phys. Proc. 15, 017 (2024) · published 3 April 2024 | Toggle abstract · pdf

  The recent results on Charmonium and Charmonium-like states at BESIII are reviewed, including the observation of $\rm Z_{cs}(3985)$ state, the study of the new decay modes of $\psi_2(3823)$ state, observation of resonance structure in $\rm e^+e^- \to \pi^+\pi^-\psi_2(3823)$ process, the study of the $\rm e^+e^- \to K^+K^-J/\psi$ process, cross section measurement of $\rm e^+e^- \to \omega\pi^0$ and $\omega\eta$ process, branching fraction measurement of $\psi(3686)\to\bar{\Sigma}^0\Lambda + c.c.$ process. Decay channels for $\chi_{cJ} \to \Lambda\bar{\Lambda}$, $\chi_{cJ} \to \Lambda\bar{\Lambda}\eta$, $\psi(3686) \to \Lambda\bar{\Lambda}\omega$ and $\eta_c(2S)\to3(\pi^+\pi^-)$ are also discussed. The property of the spin singlet P wave Charmonium state, $\rm h_c$ is also reported.

• Current stage of studies of the star configurations at intermediate energies with the use of the BINA detector

  A. Wilczek, A. Szadzinski, K. Bodek, I. Ciepal, M. Eslami-Kalantari, N. Kalantar-Nayestanaki, G. Khatri, St. Kistryn, B. Klos, A. Kozela, J. Kubos, P. Kulessa, A. Lobejko, A. Magiera, H. Mardanpour, J. Messchendorp, I. Mazumdar, W. Parol, A. Ramazani-Moghaddam-Aran, R. Ramazani-Sharifabadi, D. Rozpedzik, I. Skwira-Chalot, E. Stephan, B. Wloch, A. Wronska, J. Zejma

  SciPost Phys. Proc. 3, 005 (2020) · published 24 February 2020 | Toggle abstract · pdf

  The Space Star Anomaly in proton-deuteron breakup cross-section occurs at energies of about 10 MeV. Data for higher energies are sparse. Therefore, a systematic scan over star configurations in the range of intermediate energies between 50 and 100 MeV/nucleon is carried out on the basis of data collected with the large acceptance BINA detector. The preliminary cross section results for forward star configurations at 80 MeV/nucleon slightly surpass the theoretical calculations, but the systematic uncertainties are still under study. Also, a new variable describing rotation of star configurations is proposed.

• Floquet engineering of axion and high-Chern number phases in a topological insulator under illumination

  Mohammad Shafiei, Farhad Fazileh, François M. Peeters, Milorad V. Milošević

  SciPost Phys. Core 7, 024 (2024) · published 1 May 2024 | Toggle abstract · pdf

  Quantum anomalous Hall, high-Chern number, and axion phases in topological insulators are characterized by its Chern invariant C (respectively, C=1, integer C>1, and C=0 with half-quantized Hall conductance of opposite signs on top and bottom surfaces). They are of recent interest because of novel fundamental physics and prospective applications, but identifying and controlling these phases has been challenging in practice. Here we show that these states can be created and switched between in thin films of Bi$_2$Se$_3$ by Floquet engineering, using irradiation by circularly polarized light. We present the calculated phase diagrams of encountered topological phases in Bi$_2$Se$_3$, as a function of wavelength and amplitude of light, as well as sample thickness, after properly taking into account the penetration depth of light and the variation of the gap in the surface states. These findings open pathways towards energy-efficient optoelectronics, advanced sensing, quantum information processing and metrology.

• Ultra-high energy neutrinos searches with the Pierre Auger Observatory

  Marta Trini for the Pierre Auger Collaboration

  SciPost Phys. Proc. 1, 047 (2019) · published 22 February 2019 | Toggle abstract · pdf

  In the EeV range, neutrinos are expected to be produced by ultra-high energy cosmic rays interactions with the Cosmic Microwave Background during propagation in the Universe. We report on the search for ultra-high energy neutrinos in data collected with the Surface Detector of the Pierre Auger Observatory. The searches are most efficient in the zenith angle range from 60 degrees to 95 degrees with tau neutrinos skimming in the Earth playingdominant role. The present non-detection of UHE neutrinos in the Pierre Auger Observatory excludes the most optimistic scenarios of neutrino production in terms of UHE cosmic rays chemical composition and cosmological evolution of the acceleration sites. We also report on the searches for neutrinos in coincidence with the recent Gravitational Wave events detected by LIGO/Virgo.

• The impact of ATLAS $V$+jet measurements on PDF fits

  Eimear Conroy

  SciPost Phys. Proc. 10, 012 (2022) · published 10 August 2022 | Toggle abstract · pdf

  The production of $W$/$Z$-bosons in association with jets is an important test of perturbative QCD predictions and also yields information about the parton distribution functions of the proton. We present fits to determine PDFs using inclusive $W$/$Z$-boson and $W$/$Z$+jets measurements from the ATLAS experiment at the LHC. The ATLAS measurements are used in combination with deep-inelastic scattering data from HERA. An improved determination of the sea-quark densities at high Bjorken-$x$ is seen, while confirming a strange-quark density similar in size to the up- and down-sea-quark densities in the range $x<0.02$ found by previous ATLAS analyses.