Publications

Order by: publication date number of 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

• Status of the Muon g-2 experiment at Fermilab

  A. Driutti for the Muon g-2 Collaboration

  SciPost Phys. Proc. 1, 033 (2019) · published 21 February 2019 | Toggle abstract · pdf

  The aim of the Muon g − 2 Experiment at Fermilab (E989) is to measure the muon anomalous magnetic moment (aμ) with a relative precision of 140 parts- per-billion (ppb). This precision, which is a factor of four improvement from the current experimental result, will allow for a much more stringent test of the Standard Model. This paper present the current status of the experimental measurement of aμ after the first physics run.

  2 citations

• Lund jet plane for Higgs tagging

  Charanjit K. Khosa

  SciPost Phys. Proc. 10, 011 (2022) · published 10 August 2022 | Toggle abstract · pdf

  We study the boosted Higgs tagging using the Lund jet plane. The convolutional neural network is used for the Lund images data set to classify hadronically decaying Higgs from the QCD background. We consider $H\to b \bar{b}$ and $H \to gg$ decay for moderate and high Higgs transverse momentum and compare the performance with the cut based approach using the jet color ring observable. The approach using Lund plane images provides good tagging efficiency for all the cases.

  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

• Hadron structure from basis light-front quantization

  Chandan Mondal, Jiangshan Lan, Kaiyu Fu, Siqi Xu, Zhi Hu, Xingbo Zhao, James P. Vary

  SciPost Phys. Proc. 10, 036 (2022) · published 11 August 2022 | Toggle abstract · pdf

  We present our recent progress in applying basis light-front quantization approach to investigate the structure of the light mesons and the nucleon.

  2 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

• Test lepton flavor universality with (semi)leptonic $D$ decays at BESIII

  S. F. Zhang on behalf of the BESIII Collaboration

  SciPost Phys. Proc. 1, 016 (2019) · published 19 February 2019 | Toggle abstract · pdf

  Using 2.93~fb$^{-1}$ data taken at $\sqrt{s}=3.773$~GeV, 0.482~fb$^{-1}$ data taken at $\sqrt{s}=4.009$~GeV and 3.19~fb$^{-1}$ data taken at $\sqrt{s}=4.178$~GeV with the BESIII detector, precision measurements of the branching fractions of $D^0\to K^-\mu^+\nu_\mu$, $D^+\to\bar K^0\mu^+\nu_\mu$, $D^0\to\pi^-\mu^+\nu_\mu$, $D^+\to\pi^0\mu^+\nu_\mu$, $D^+\to\ell^+\nu_\ell$ and $D_s^+\to\ell^+\nu_\ell$ are performed. Combining the known branching fractions of $D\to\bar Ke^+\nu_e$, $D\to\pi e^+\nu_e$ and $D^+_s\to\tau^+\nu_\tau$, we have tested the lepton flavor universality with $D\to\bar K\ell^+\nu_\ell$, $D\to\pi\ell^+\nu_\ell$, $D^+\to\ell^+\nu_\ell$ and $D_{s}^+\to\ell^+\nu_\ell$ decays. We have also tested lepton flavor universality in different $q_{\ell\nu_\ell}^2$ intervals for $D\to\bar K\ell^+\nu_\ell$~($\ell=e$ or $\mu$). Besides, hadronic form factor $f_+^K(0)$, $D$ meson decay constant $f_{D_s^+}$ and $f_{D^+}$, and quark mixing matrix element $|V_{cs}|$ and $|V_{cd}|$ are also extracted with the most precise accuracies to date.

  2 citations

• The SINDRUM-I Experiment

  Ralph Eichler, Christoph Grab

  SciPost Phys. Proc. 5, 007 (2021) · published 6 September 2021 | Toggle abstract · pdf

  SINDRUM-I was the first nearly 4 spectrometer at SIN. It was initially designed to 9 search for the forbidden decay + ! e+e􀀀e+ , but also successfully studied various 10 other processes with high precision. The upper limit obtained for the branching ratio of B!3e = 􀀀 (+ ! e+e􀀀e+ )=􀀀 (+ ! e+e¯ 11  ) < 1.0  10􀀀12(90% CL) from 1988 is still the best. The first statistically significant observation of the rare decay + ! e+e􀀀e+e¯ 12  , achieved in 1985, yielded a branching ratio of B13 !3e2 = (3.40.20.2)10􀀀5. Several 14 othermeasurements of rare decays were undertaken: the first observation of the -decay 15 + !e+ee􀀀e+ resulted in 􀀀 (+ !e+ee􀀀e+ )=􀀀 (+ !+ ) = (3.2  0.5  0.2)  10􀀀9, 16 also still the best measurement; and a determination of the ratio of the weak axial- to 17 vector-form factor FA=FV = (0.7  0.5), resolving an ambiguity. In addition, upper limits 18 for + ! e+ and + ! e+e with subsequent decay ! e+e􀀀 (search for "massless" Goldstone bosons) and 0 !e+e􀀀 19 < 1.3  10􀀀7 were obtained.

  2 citations

• Study of deuteron-proton backward elastic scattering at intermediate energies

  Nadezhda Ladygina

  SciPost Phys. Proc. 3, 053 (2020) · published 27 February 2020 | Toggle abstract · pdf

  We study deuteron- proton elastic scattering in the deuteron energy range between 500 MeV and 2~GeV at the cms scattering angle $\theta^*\ge 140^\circ$. The reaction is considered in the relativistic multiple scattering expansion framework. The four reaction mechanisms are included into consideration: one-nucleon exchange, single scattering, double scattering, and the term corresponding to the delta excitation in the intermediate state. The model is applied to describe the angular dependence of the differential cross section at the deuteron energies of between 880 and 1300 MeV. Also the energy dependence of the differential cross section and polarisation observables such as tensor analyzing power $T_{20}$ and polarization transfer from the deuteron to proton $\varkappa$ are considered at the scattering angle equal to 180$^\circ$. Contributions of the different reaction mechanisms into the reaction amplitude are demonstrated in comparison with the existing experimental data.

  2 citations

• Virial expansion coefficients in the unitary Fermi gas

  Shimpei Endo

  SciPost Phys. Proc. 3, 049 (2020) · published 27 February 2020 | Toggle abstract · pdf

  Virial expansion is widely used in cold atoms to analyze high temperature strongly correlated many-body systems. As the n-th order virial expansion coefficient can be accurately obtained by exactly solving up to n-body problems, the virial expansion offers a few-body approach to study strongly correlated many-body problems. In particular, the virial expansion has successfully been applied to unitary Fermi gas. We review recent progress of the virial expansion studies in the unitary Fermi gas, in particular the fourth order virial coefficient.

  2 citations