Publications

Order by: publication date number of citations

• Analysis of radiation damage in silicon charge-coupled devices used for dark matter searches

  Steven J. Lee

  SciPost Phys. Proc. 12, 030 (2023) · published 4 July 2023 | Toggle abstract · pdf

  Nuclear recoils in crystal detectors generate radiation damage in the form of crystal defects that can be measured in scientific-grade CCDs as local hot spots of leakage current stimulated by temperature increases in the devices. In this proceeding, we use a neutron source to generate defects in DAMIC-M CCDs, and using increases in leakage current at different temperatures, we demonstrate a procedure for identifying crystal defects in the CCDs of the DAMIC-M experiment. This is the first time that individual defects generated from nuclear recoils have been studied. This technique could be used to distinguish nuclear recoils from electron recoils in some energy ranges, which would improve the ability of CCD detectors to search for weakly interacting dark matter.

  2 citations

• Particle Physics at PSI

  A. Signer, K. Kirch, C. M. Hoffman

  SciPost Phys. Proc. 5, 001 (2021) · published 6 September 2021 | Toggle abstract · pdf

  Particle physics results of constant value and significant impact have been obtained at PSI, and several efforts are presently ongoing and expected to deliver new findings in the near future. In this special SciPost volume we collect them together in a concise manner. Not yet included are ideas for future facility upgrades or completely new experimental efforts, but we are set to extend this volume in the years to come.

  1 citation

• Muon Decay

  W. Fetscher

  SciPost Phys. Proc. 5, 006 (2021) · published 6 September 2021 | Toggle abstract · pdf

  The decay of the muon has been studied at PSI with several precision measurements: The longitudinal polarization PL(E) with the muon decay parameters ξ′, ξ′′, the Time- Reversal Invariance (TRI) conserving transverse polarization PT1(E) with the muon de- cay parameters η, η′′, the TRI violating transverse polarization PT2(E), with α′/A, β′/A and the muon decay asymmetry with Pμξ. The detailed theoretical analysis of all mea- surements of normal and inverse muon decay has led for the first time to a lower limit |g V | > 0.960 ("V − A") and upper limits for nine other possible complex couplings, espe- cially the scalar coupling |g S | < 0.550 which had not been excluded before.

  1 citation

• Prospects for $\tau$ lepton physics at Belle II

  Michel Hernandez Villanueva on behalf of the Belle II collaboration

  SciPost Phys. Proc. 1, 003 (2019) · published 18 February 2019 | Toggle abstract · pdf

  The Belle II experiment is an upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric $e^+e^-$ collider. The accelerator has already successfully completed the first phase of commissioning and first electron positron-collisions in Belle II were observed in April 2018. The design luminosity of SuperKEKB is 8x10$^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than the Belle experiment. Belle II has a broad program of $\tau$ physics, in particular, precision measurements of Standard Model parameters and searches of lepton flavor and lepton number violations (LFV and LNV), benefiting from the large cross-section of the pairwise $\tau$ lepton production in $e^+e^-$ collisions. In this talk, we will review the $\tau$ lepton physics program of Belle II.

  1 citation

• Muonium-Antimuonium Conversion

  Lorenz Willmann, Klaus Jungmann

  SciPost Phys. Proc. 5, 009 (2021) · published 6 September 2021 | Toggle abstract · pdf

  The MACS experiment performed at PSI in the 1990s provided an yet unchallenged upper bound on the probability for a spontaneous conversion of the muonium atom, ${\rm M=}$($\rm{\mu^+e^-}$) , into its antiatom, antimuonium ${\overline{\rm{M}} = }$($\rm{\mu^-e^+})$. It comprises the culmination of a series of measurements at various accelerator laboratories worldwide. The experimental limits on the process have provided input and steering for the further development of a variety of theoretical models beyond the standard theory, in particular for models which address lepton number violating processes and matter-antimatter oscillations. Several models beyond the standard theory could be strongly disfavored. There is interest in a new measurement and improved sensitivity could be reached by exploiting the time evolution of the conversion process, e.g., at intense pulsed muonium sources.

  1 citation

• Photomultiplier characterisation and its impact on background for SABRE South

  William J. D. Melbourne, Owen Stanley, Phillip Urquijo, Madeleine J. Zurowski

  SciPost Phys. Proc. 12, 061 (2023) · published 5 July 2023 | Toggle abstract · pdf

  SABRE (Sodium iodide with Active Background REjection) South is a NaI(Tl) based dark matter direct detection experiment located at the Stawell Underground Physics Laboratory (SUPL) [J. Phys. Conf. Ser. 2156, 012064 (2021), arXiv:2205.13849]. It is designed to detect an annual modulation of WIMP recoils as an independent replication of the long-standing DAMA/LIBRA modulation signal. SABRE South will have a low energy threshold of 1 keV in the NaI(Tl) crystal detector and a low experimental background. This requires precise characterisation of the photomultipliers used to understand both their sensitivity at low thresholds and their contribution to the background. We report on the photomultiplier characterisation test bench developed for the crystal detector photomultipliers including studies of the single photon response, transit time, and dark noise. A specific focus is on estimating the contribution to the experimental background of coincident photomultiplier noise due to its predominance at low energy and inability to be modelled using traditional MC simulation.

  1 citation

• $μ$-$e$ conversion experiments at J-PARC

  Natsuki Teshima

  SciPost Phys. Proc. 1, 039 (2019) · published 21 February 2019 | Toggle abstract · pdf

  There are two plans of experiments to search for muon to electron ($\mu$-$e$) conversion at J-PARC, which are called DeeMe and COMET. The $\mu$-$e$ conversion is one of the charged lepton flavor violation processes. The processes are forbidden in the Standard Model, but some theories beyond the Standard Model predict relatively large branching ratios at orders of $10^{-12}$ to $10^{-17}$. DeeMe will be conducted with a sensitivity of $1\times10^{-13}$ using a carbon target for 1 year, and COMET will be done with that of $3\times10^{-15}$ in Phase-I. In this article, the current status of these two experiments will be presented.

  1 citation

• Dark sector studies with the PADME experiment

  Anna Paola Caricato, Maurizio Martino, Isabella Oceano, Federica Oliva, Stefania Spagnolo, Gabriele Chiodini, Fabio Bossi, Riccardo De Sangro, Claudio Di Giulio, Danilo Domenici, Giuseppe Finocchiaro, Luca Gennaro Foggetta, Marco Garattini, Andrea Ghigo, Federica Giacchino, Paola Gianotti, Tommaso Spadaro, Eleuterio Spiriti, Clara Taruggi, Elisabetta Vilucchi, Venelin Kozhuharov, Simeon Ivanov, Sevtoslav Ivanov, Radoslav Simeonov, Georgi Georgiev, Fabio Ferrarotto, Emanuele Leonardi, Paolo Valente, Elizabeth Long, Giovanni Organtini, Gabriele Piperno, Mauro Raggi, Salvatore Fiore, Paolo Branchini, Diego Tagnani, Vittoria Capirossi, Federico Pinna, Andre Frankenthal

  SciPost Phys. Proc. 12, 050 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The Positron Annihilation to Dark Matter Experiment (PADME) uses the positron beam of the DA$\Phi$NE Beam-Test Facility, at the Laboratori Nazionali di Frascati (LNF) to search for a Dark Photon $A'$. The search technique studies the missing mass spectrum of single-photon final states in $e^+e^-\rightarrow A'\gamma$ annihilation in a positron-on-thin-target experiment. This approach facilitates searches for new particles such as long lived Axion-Like-Particles, protophobic X bosons and Dark Higgs. This talk illustrated the scientific program of the experiment and its first physics results. In particular, the measurement of the cross-section of the SM process $e^+e^-\rightarrow \gamma\gamma$ at $\sqrt{s}$=21 MeV was shown.

  1 citation

• Searches for dark matter with the ATLAS detector

  R. Pedro on behalf of the ATLAS Collaboration

  SciPost Phys. Proc. 12, 048 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The presence of a non-baryonic Dark Matter (DM) component in the Universe is inferred from the observation of its gravitational interaction. If DM interacts weakly with Standard Model (SM) particles it could be produced at the LHC. The ATLAS experiment has developed a broad search program for DM candidates in final states with large missing transverse momentum produced in association with other SM particles (light and heavy quarks, photons, Z and H bosons, as well as additional heavy scalar particles). The results of recent searches on 13 TeV pp data, their interplay and interpretation are presented.

  1 citation

• Recent results from the TOTEM collaboration and the discovery of the odderon

  Christophe Royon

  SciPost Phys. Proc. 13, 005 (2023) · published 28 September 2023 | Toggle abstract · pdf

  We describe the most recent results from the TOTEM collaboration on elastic, inelastic and total cross sections as well as the odderon discovery by the D0 and TOTEM collaborations.

  1 citation