Publications

Order by: publication date number of citations

• The KM3NeT infrastructure: Status and first results

  Annarita Margiotta on behalf of the KM3NeT Collaboration

  SciPost Phys. Proc. 13, 030 (2023) · published 29 September 2023 | Toggle abstract · pdf

  KM3NeT is a research infrastructure in construction under the Mediterranean Sea. It hosts two large volume neutrino Cherenkov telescopes: ARCA at a depth of 3500 m, located offshore Sicily, and ORCA, 2500 m under the sea level, offshore the southern French coast. The two detectors share the same detection principle and technology and the same data acquisition design, the only difference being the geometrical arrangement of the optical sensors. This allows to span a wide range of neutrino energy and cover a large scientific program: The study of neutrino properties, first of all neutrino mass ordering, the identification and study of high energy neutrino astrophysical sources, indirect dark matter searches and core collapse supernovae detection.

• ALICE at the LHC and astrophysics: From providing input for the search for antinuclei in space to constraining the equation of state of neutron stars

  Alexander Kalweit on behalf of the ALICE collaboration

  SciPost Phys. Proc. 13, 022 (2023) · published 29 September 2023 | Toggle abstract · pdf

  The ALICE experiment at the LHC was originally designed to study the creation of the quark-gluon-plasma in heavy-ion collisions, a new state of matter in which quarks and gluons are not confined into hadrons. More recently, the versatility of both the Large Hadron Collider and the ALICE apparatus have given additionally access to a unique set of nuclear and hadronic physics measurements. The main results from this new and dynamic research area will be presented. The application of these findings to astrophysical challenges, ranging from the equation of state of neutron stars to the search for dark matter in space, will be discussed.

• Uncertainty in mean $X_{\rm max}$ from diffractive dissociation estimated using measurements of accelerator experiments

  Ken Ohashi, Hiroaki Menjo, Takashi Sako, Yoshitaka Itow

  SciPost Phys. Proc. 13, 018 (2023) · published 28 September 2023 | Toggle abstract · pdf

  Mass composition is important for understanding the origin of ultra-high-energy cosmic rays. However, interpretation of mass composition from air shower experiments is challenging, owing to significant uncertainty in hadronic interaction models adopted in air shower simulation. A particular source of uncertainty is diffractive dissociation, as its measurements in accelerator experiments demonstrated significant systematic uncertainty. In this research, we estimate the uncertainty in $\langle X_{\rm max}\rangle$ from the uncertainty of the measurement of diffractive dissociation by the ALICE experiment. The maximum uncertainty size of the entire air shower was estimated to be $^{+4.0}_{-5.6} \mathrm{g/cm^2}$ for air showers induced by $10^{17}$ eV proton, which is not negligible in the uncertainty of $\langle X_{\rm max}\rangle$ predictions.

• A measurement of the proton plus helium spectrum of cosmic rays in the TeV region with HAWC

  Juan Carlos Arteaga-Velázquez on behalf of the HAWC collaboration

  SciPost Phys. Proc. 13, 015 (2023) · published 28 September 2023 | Toggle abstract · pdf

  HAWC is an air-shower detector designed to study TeV gamma and cosmic rays. The observatory is composed of a 22000 $m^2$ array of 300 water Cherenkov tanks (4.5 m deep x 7.3 m diameter) with 4 photomultipliers (PMT) each. The instrument registers the number of hit PMTs, the timing information and the total charge at the PMTs during the event. From these data, shower observables such as the arrival direction, the core position at ground, the lateral age and the primary energy are estimated. In this work, we study the distribution of the shower age vs the primary energy of a sample of shower data collected by HAWC from June 2015 to June 2019 and employ a shower-age cut based on predictions of QGSJET-II-04 to separate a subsample of events dominated by H and He primaries. Using these data and a dedicated analysis, we reconstruct the cosmic ray spectrum of H+He from 6 to 158 TeV, which shows the presence of a softening at around 24 TeV with a statistical significance of 4.1$\sigma$.

• Measuring single-top-associated Higgs production at the HL-LHC

  Henning Bahl

  SciPost Phys. Proc. 8, 010 (2022) · published 11 July 2022 | Toggle abstract · pdf

  Precision measurements of top-associated Higgs production are an important ingredient to unravel the $\mathcal{CP}$ nature of the Higgs boson. In this work, we constraint the $\mathcal{CP}$ nature of the top-Yukawa coupling taking into account all relevant inclusive and differential Higgs boson measurements. Based upon this fit, we show that it is crucial to disentangle single- and di-top-associated Higgs production for tightening indirect constraints on a $\mathcal{CP}$-odd top-Yukawa coupling in the future. In this context, we propose an analysis strategy for measuring $tH$ production at the HL-LHC without relying on assumptions about the Higgs $\mathcal{CP}$ character.

• A new method to extract the valence transversity distributions

  Mauro Anselmino, Raj Kishore, Asmita Mukherjee

  SciPost Phys. Proc. 8, 052 (2022) · published 12 July 2022 | Toggle abstract · pdf

  A new method is suggested for the extraction of $u$-quark and $d$-quark transversity distributions, using single spin asymmetry (SSA) data in semi-inclusive deep inelastic scattering (SIDIS) processes, where they couple to the Collins or the di-hadron fragmentation functions. We discuss a recent suggestion to extract the transversity distribution using the concept of difference asymmetries and their ratios, which avoids the requirement of Collins function. We suggest new measurements, involving ratios of polarized cross-sections, that would directly probe the ratio $h_1^{d_v}/h_1^{u_v}$. We also show some numerical estimates.

• Limits to gauge coupling in the dark sector of super-heavy dark matter particles from the Pierre Auger Observatory data

  Olivier Deligny for the Pierre Auger Collaboration

  SciPost Phys. Proc. 13, 013 (2023) · published 28 September 2023 | Toggle abstract · pdf

  Assuming that the energy density of super-heavy particles matches that of dark matter observed today, tight constraints on the couplings governing the decay process are presented as a function of the particle mass. These constraints are obtained from the lack of signatures that would be suggestive of decaying super-heavy $X$ particles in the data of the Pierre Auger Observatory. In particular, instanton-induced decay processes allow us to derive a bound on the reduced coupling constant of gauge interactions in the dark sector: $\alpha_X \lesssim 0.09$, for $10^{9} \lesssim M_X/\mathrm{GeV} < 10^{19}$. Cosmological aspects for super-heavy dark matter production during the reheating epoch are discussed.

• Results on high energy galactic cosmic rays from the DAMPE space mission

  Leandro Silveri on behalf of the DAMPE Collaboration

  SciPost Phys. Proc. 13, 012 (2023) · published 28 September 2023 | Toggle abstract · pdf

  DAMPE (Dark Matter Particle Explorer) is a satellite-born experiment launched in 2015 in a sun-synchronous orbit at 500 km altitude, and it has been taking data in stable conditions ever since. Its main goals include the spectral measurements up to very high energies, cosmic electrons/positrons and gamma rays up to tens of TeV, and protons and nuclei up to hundreds of TeV. The detector's main features include the 32 radiation lengths deep calorimeter and large geometric acceptance, making DAMPE one of the most powerful space instruments in operation, covering with high statistics and small systematics the high energy frontier up to several hundreds TeV. The results of spectral measurements of different species are shown and discussed.

• The ALPACA experiment: The project of the first sub-PeV gamma-ray observation in the southern sky

  Teruyoshi Kawashima for the ALPACA Collaboration

  SciPost Phys. Proc. 13, 008 (2023) · published 28 September 2023 | Toggle abstract · pdf

  The ALPACA experiment is a project aiming to observe sub-PeV gamma rays for the first time in the southern hemisphere. The main goal of ALPACA is to identify PeVatrons, the accelerators of Galactic PeV cosmic rays, by observing sub-PeV pion-decay gamma rays generated in interactions between PeV cosmic rays and the interstellar medium. This new air shower experiment is located at an altitude of 4,740 m above sea level in the middle of Mt. Chacaltaya in Bolivia. The air shower array consists of 401 scintillation counters covering an 83,000 m$^2$ surface area. In addition, a water-Cherenkov-type muon detector array with an area of 3,700 m$^2$ is installed to discriminate gamma rays from background cosmic rays. The prototype array ALPAQUITA will start data taking in 2022 and will extend to ALPACA in 2024. We report on a general introduction to ALPACA, the progress of the project, and the sensitivity to sub-PeV gamma rays.

• Background field method and generalized field redefinitions in effective field theories

  Andrea Quadri

  SciPost Phys. Proc. 7, 045 (2022) · published 22 June 2022 | Toggle abstract · pdf

  We study the non-linear background field redefinitions arising at the quantum level in a spontaneously broken effective gauge field theory. The non-linear field redefinitions are crucial for the symmetric (i.e. fulfilling all the relevant functional identities of the theory) renormalization of gauge-invariant operators. In a general $R_\xi$-gauge the classical background-quantum splitting is also non-linearly deformed by radiative corrections. In the Landau gauge these deformations vanish to all orders in the loop expansion.