Publications

Order by: publication date number of citations

• Description of continuum structures in a discrete basis: Three-body resonances and two-nucleon decays

  Jesús Casal, Manuela Rodríguez-Gallardo, José M. Arias, Joaquín Gómez-Camacho, Lorenzo Fortunato, Andrea Vitturi

  SciPost Phys. Proc. 3, 036 (2020) · published 26 February 2020 | Toggle abstract · pdf

  Weakly bound and unbound three-body nuclei are studied by using the pseudostate method within the hyperspherical formalism. After introducing the theoretical framework, the method is applied first to the $\boldsymbol{^9}$Be nucleus, showing a good agreement with the available data for its low-lying dipole response. Then, recent results on the structure and decay of the two-neutron emitters $\boldsymbol{^{26}}$O and $\boldsymbol{^{16}}$Be are presented. In particular, the role of the $\boldsymbol{n}$-$\boldsymbol{n}$ correlation in shaping their properties is discussed.

  2 citations

• A theory vade mecum for PSI experiments

  G. Colangelo, F. Hagelstein, A. Signer, P. Stoffer

  SciPost Phys. Proc. 5, 005 (2021) · published 6 September 2021 | Toggle abstract · pdf

  This article gives a compact introduction and overview of the theory underlying the experiments described in the rest of this review.

  2 citations

• An investigation of the appearance of a long range nuclear potential in ultra low energy nuclear synthesis

  Shinsho Oryu, Takashi Watanabe, Yasuhisa Hiratsuka, Masayuki Takeda

  SciPost Phys. Proc. 3, 050 (2020) · published 27 February 2020 | Toggle abstract · pdf

  A new potential, the $general$ $particle$ $transfer$ $potential$: so called ``GPT'' potential was represented in the previous paper which indicates a Yukawa-type potential for shorter range, but a $1/r^n$-type potential for longer range where $n=2$ includes the Efimov-like potential in the hadron system. In order to confirm the existence of a GPT potential, we investigate the possibility of Cs+2d$\rightarrow$La reaction on the three-ion quasi-molecule CsD$_2$ which is covered by twelve Pd or a CsD$_2$Pd$_{12}$-cluster, where the three-body bound states and wave functions for D-Cs-D molecular and d-Cs-d nuclear systems are calculated. We obtain an approximate E2-transition from the molecular states to the nuclear states. The transition ratio between the short range nuclear potential with the $1/r^2$-type long range potential and without long range potential is $W_{i\rightarrow f}^{E2';L}/W_{i\rightarrow f}^{E2';S}\approx 10^8$. If the reaction Cs+2D$\rightarrow$La is experimentally observed, then the existence of the GPT potential could be confirmed.

  2 citations

• Recent results of laser spectroscopy experiments of pionic helium atoms at PSI

  M. Hori, H. Aghai-Khozani, A. S\'ot\'er, A. Dax, D. Barna

  SciPost Phys. Proc. 5, 026 (2021) · published 6 September 2021 | Toggle abstract · pdf

  A review of a recent experiment carried out at PSI involving laser spectroscopy of metastable pionic helium ($\pi{\rm ^4He}^+\equiv\pi^{-}+{\rm ^4He}^{2+}+e^-$) atoms is presented. An infrared transition $(n,\ell)=(17,16)$$\rightarrow$$(17,15)$ at a resonance frequency of $\nu\approx 183760$ GHz was detected.

  2 citations

• Sub-GeV dark matter searches with EDELWEISS: New results and prospects

  Hugues Lattaud on behalf of the EDELWEISS collaboration

  SciPost Phys. Proc. 12, 012 (2023) · published 3 July 2023 | Toggle abstract · pdf

  The Edelweiss collaboration performs light Dark Matter (DM) particles searches with germanium bolometer collecting charge and phonon signals. Thanks to the Neganov-Trofimov-Luke (NTL) effect, a RMS resolution of 4.46 electron-hole pairs was obtained on a massive (200g) germanium detector instrumented with a NbSi Transition Edge Sensor (TES) operated underground at the Laboratoire Souterrain de Modane (LSM). This sensitivity made possible a search for WIMP using the Migdal effect down to 32 MeV/C$^{2}$ and exclude cross-sections down to 10$^{-29}$ cm$^2$. It is the first measurement in cryogenic germanium with such thermal sensor, proving the high relevance of this technology. Furthermore, such TES have shown sensitivity to out-of-equilibrium phonons, paving the way for EDELWEISS new experience CRYOSEL. This is an important step in the development of Ge detectors with improved performance in the context of the EDELWEISS-SubGeV program.

  2 citations

• Directional dark matter searches

  Elisabetta Baracchini

  SciPost Phys. Proc. 12, 002 (2023) · published 3 July 2023 | Toggle abstract · pdf

  The importance of directly detect and experimentally probe the nature of Dark Matter (DM) is universally and incontrovertibly recognised as one of the most compelling tasks of today's fundamental physics. Directional DM searches aim at developing experimental techniques that can give access to the measurement of the incoming direction of the DM particle. This can provide a correlation with an astrophysical source that no background whatsoever can mimic and offers an unique key for a positive, unambiguous identification of a DM signal.

  2 citations

• The status of the galactic center gamma-ray excess

  Dan Hooper

  SciPost Phys. Proc. 12, 006 (2023) · published 3 July 2023 | Toggle abstract · pdf

  The Galactic Center Gamma-Ray Excess has a spectrum, angular distribution, and overall intensity that agree remarkably well with that expected from annihilating dark matter particles in the form of a $m_X \sim$ 50 GeV thermal relic. Previous claims that these photons are clustered on small angular scales or trace the distribution of known stellar populations once appeared to favor interpretations in which this signal originates from a large population of unresolved millisecond pulsars. More recent work, however, has overturned these conclusions, finding that the observed gamma-ray excess does not contain discernible small scale power, and is distributed with approximate spherical symmetry, not tracing any known stellar populations. In light of these results, it now appears significantly more likely that the Galactic Center Gamma-Ray Excess is produced by annihilating dark matter.

  2 citations

• Forward Higgs production at NLO using Lipatov's high energy effective action

  Martin Hentschinski

  SciPost Phys. Proc. 8, 136 (2022) · published 14 July 2022 | Toggle abstract · pdf

  We use Lipatov's high energy effective action to determine the next-to-leading order corrections to Higgs production in the forward region. As a new element we provide a proper definition of the desired next-to-leading order coefficient within the high energy effective action framework, extending a previously proposed prescription. We further propose a subtraction mechanism to achieve for this coefficient a stable cancellation of real and virtual infra-red singularities in the presence of external off-shell legs and discuss aspects related to choice of a reference scale for high energy resummation.

  2 citations

• Impact parameter dependence of color charge correlations in the proton

  Adrian Dumitru, Heikki Mäntysaari, Risto Paatelainen

  SciPost Phys. Proc. 8, 058 (2022) · published 12 July 2022 | Toggle abstract · pdf

  The impact parameter dependence of color charge correlators in the proton is obtained from the light front formalism in light cone gauge. We include NLO corrections due to the $|qqqg\rangle$ Fock state via light-cone perturbation theory. Near the center of the proton, the $b$-dependence of the correlations is very different from a "transverse profile function". The resulting $t$-dependence of exclusive $J/\Psi$ photoproduction transitions from exponential to power law at $|t| \approx 1$ GeV$^2$. This prediction could be tested at upcoming DIS facilities or in nucleus-proton ultraperipheral collisions (UPCs).

  2 citations

• Can we really detect relic neutrinos?

  Yevheniia Cheipesh, Ivan Ridkokasha, Vadim Cheianov, Alexey Boyarsky

  SciPost Phys. Proc. 12, 042 (2023) · published 4 July 2023 | Toggle abstract · pdf

  Detecting relic neutrinos is a longstanding goal in fundamental physics. Experimentally, this goal is extremely challenging as the required energy resolution is defined by the tiny neutrino masses ($\sim$ 10 meV). The current consensus is that sufficient statistics together with a clean spectrum could only be achieved if beta decayers are attached to a solid state substrate. However, this inevitably imposes irreducible intrinsic limitations on the energy resolution coming from Heisenberg's uncertainty principle. This limitation appears to be critical for the currently accepted decayer - Tritium. Here, we analyze the state of the art approaches to mitigate this limitation and conclude that the most promising solution is to change Tritium for a heavier emitter. We find that the two suitable candidates are $^{171}$Tm, $^{63}$Ni.

  2 citations