Publications

Order by: publication date number of citations

• Hadron Production in terms of Green's Functions in Non-Equilibrium Matter

  A. V. Koshelkin

  SciPost Phys. Proc. 10, 037 (2022) · published 11 August 2022 | Toggle abstract · pdf

  Following the quark-hadron duality concept, we show that the number of hadrons generated in the deconfinement matter is entirely determined by the exact non-equilibrium Green's functions of partons in the medium and the vertex function governing the probability of the confinement-deconfinement phase transition. In such an approach, compactifying the standard (3+1) chromodynamics into $ QCD_{xy} + QCD_{zt}$, the rate of the hadrons produced in particle collisions is derived in the explicit form provided that the hadronization is the first order phase transition. The pion production is found to be in good agreement to the experimental results on the pion yield in pp collisions.

• Measurements of $W$ and $Z/γ^*$ cross sections and their ratios in $pp$ collisions at STAR

  Jae Nam

  SciPost Phys. Proc. 8, 140 (2022) · published 14 July 2022 | Toggle abstract · pdf

  While the unpolarized parton distribution functions of the valence quarks ($d$ and $u$) are well determined from DIS experiments, the sea quark counterparts, $\bar{d}$ and $\bar{u}$, are much less constrained, in particular, near the valence region. Measurements of $W^+/W^-$ production ratio in $pp$ collider experiments, such as the STAR experiment at RHIC, can probe the $\bar{d}/\bar{u}$ ratio at a large $Q^2$ set by the $W$ mass. These proceedings will discuss recent results of $W$ and $Z$ cross-section measurements using the STAR $pp$ collision data at a center-of-mass energy of $\sqrt{s} = 500/510\;\mathrm{GeV}$ collected in 2011, 2012, 2013 and 2017.

• Photon TMDs from uPDFevolv

  Hannes Jung, Sara Taheri Monfared, Thomas Wening

  SciPost Phys. Proc. 8, 132 (2022) · published 13 July 2022 | Toggle abstract · pdf

  We present photon TMDs generated using the Parton Branching Method with QED evolution. We discuss the TMD’s properties and compare it to the gluon TMD. Two sets of TMDs differing in their initial evolution scale and the choice of the renormalisation scale are defined and compared to each other.

• $\Lambda$ Polarizing Fragmentation Function from Belle $e^+ e^-$ data

  Umberto D'Alesio, Francesco Murgia, Marco Zaccheddu

  SciPost Phys. Proc. 8, 131 (2022) · published 13 July 2022 | Toggle abstract · pdf

  Experimental data from Belle Collaboration for the transverse polarization of $\Lambda$'s measured in $e^+ e^-$ annihilation processes are used to extract the polarizing fragmentation function (FF) within a TMD approach. We consider both associated and inclusive $\Lambda$ production, showing a quite consistent scenario. Good separation in flavor is obtained, leading to four independent FFs. Predictions for SIDIS processes at the EIC, crucial for understanding their universality and evolution properties, are also presented.

• Calculation of asymptotic normalization coefficients in the complex-ranged Gaussian basis

  Dinmukhamed A. Sailaubek, Olga A. Rubtsova

  SciPost Phys. Proc. 3, 043 (2020) · published 27 February 2020 | Toggle abstract · pdf

  A new technique towards finding asymptotic normalization coefficients in the complex-ranged Gaussian basis is presented. It is shown that a diagonalisation procedure for the total Hamiltonian matrix in the given basis results in approximation for a radial part of the bound state wave function from the origin up to the far asymptotic distances, which allows to extract ANCs rather accurately. The method is illustrated by calculations of single-particle ANCs for nuclei bound states in cases of non-local nucleon-nucleus interactions, in particular, phenomenological global potentials with the Perey-Buck's non-locality.

• Annihilating dark matter search with 12 years of Fermi LAT data in nearby galaxy clusters

  Charles Thorpe-Morgan, D. Malyshev, C.-A. Stegen, Andrea Santangelo, J. Jochum

  SciPost Phys. Proc. 12, 071 (2023) · published 10 July 2023 | Toggle abstract · pdf

  Galaxy clusters contain an abundance of dark matter making them attractive laboratories for indirect DM searches. This work details a search for signals of pair annihilation from WIMP dark matter in the GeV gamma ray regime. We perform this search in five low $z$ and high galactic latitude galaxy clusters (Centaurus, Coma, Virgo, Perseus and Fornax); using nearly 12 years of Fermi/LAT data. Through the non-detection of this characteristic signal, we derive constraints on the annihilation cross-section of DM pair annihilation into the $b\overline{b}$, $W^+W^-$ and $\gamma\gamma$ channels. The limits obtained are of a comparable magnitude to those of recently derived from Fermi/LAT observations of dwarf spheroidal galaxies.

• Application of the JISP16 potential to the nucleon induced deuteron breakup process at E=13 MeV and E=65 MeV

  Volodymyr Soloviov1, Jacek Golak, Roman Skibiński, Kacper Topolnicki, and Henryk Witała

  SciPost Phys. Proc. 3, 032 (2020) · published 26 February 2020 | Toggle abstract · pdf

  The JISP16 nucleon-nucleon potential has been applied to investigations of the nucleon induced deuteron breakup reaction at the incoming nucleon laboratory energies E = 13 MeV and E = 65 MeV. We have found that for the studied process the JISP16 force gives a description of the exclusive cross section, which is generally similar to the ones obtained with the standard realistic nucleon-nucleon AV18 interaction. However, there are some regions of the phase space where the differential cross sections predicted by the JISP16 and AV18 models, differ by more than 100 %. These special kinematical configurations may possibly be useful to refit the JISP16 force parameters.

• Global fits of Dirac dark matter effective field theories

  Ankit Beniwal (On behalf of the GAMBIT Collaboration)

  SciPost Phys. Proc. 12, 044 (2023) · published 4 July 2023 | Toggle abstract · pdf

  In this proceeding, we present results from a global fit of Dirac fermion dark matter (DM) effective field theory (EFT) based on arXiv:2106.02056 using the GAMBIT framework. Here we show results only for the dimension-6 operators that describe the interactions between a gauge-singlet Dirac fermion and Standard Model quarks. Our global fit combines the latest constraints from Planck, direct and indirect DM detection, and the LHC. For DM mass below 100 GeV, it is impossible to simultaneously satisfy all constraints while maintaining the EFT validity at high energies. For higher masses, however, large regions of parameter space remain viable where the EFT is valid and saturates the observed DM abundance.

• ISAI: Investigating Solar Axion by Iron-57

  Tomonori Ikeda, Toshihiro Fujii, Takeshi Go Tsuru, Yuki Amano, Kazuho Kayama, Masamune Matsuda, Hiromu Iwasaki, Mizuki Uenomachi, Kentaro Miuchi, Yoshiyuki Onuki, Yoshizumi Inoue, Akimichi Taketa

  SciPost Phys. Proc. 12, 041 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The existence of the axion is a unique solution for the strong CP problem, and the axion is one of the most promising candidates of the dark matter. Investigating Solar Axion by Iron-57 (ISAI) is being prepared as a complemented table-top experiment to confirm the solar axion scenario. Probing an X-ray emission from the nuclear transitions associated with the axion-nucleon coupling is a leading approach. ISAI searches for the monochromatic 14.4 keV X-ray from the first excited state of $^{57}$Fe using a state-of-the-art pixelized silicon detector, dubbed XRPIX, under an extremely low-background environment. We highlight scientific objectives, experimental design and the latest status of ISAI.

• Intrinsic charm in the nucleon and forward production of charm: a new constrain from IceCube Neutrino Observatory

  Rafał Maciuła, Victor P. Goncalves, Antoni Szczurek

  SciPost Phys. Proc. 8, 124 (2022) · published 13 July 2022 | Toggle abstract · pdf

  The predictions for the atmospheric neutrino flux at high energies strongly depend on the contribution of prompt neutrinos, which are determined by the production of charmed meson in the atmosphere at very forward rapidities. Here we estimate the related cross sections taking into account the presence of an intrinsic charm (IC) component in the proton wave function. The impact on the predictions for the prompt neutrino flux is investigated assuming different values for the probability to find the IC in the nucleon.