Publications

Order by: publication date number of citations

• Anomalous coupling studies with forward protons at the LHC

  C. Royon

  SciPost Phys. Proc. 8, 115 (2022) · published 13 July 2022 | Toggle abstract · pdf

  We describe the gain on sensitivities to quartic $\gamma \gamma \gamma \gamma$, $\gamma \gamma WW$ and $\gamma \gamma \gamma Z$ anomalous couplings and to the search for Axion-Like Particles by two or three orders of magnitude with respect to standard methods at the LHC by tagging intact protons in the final state.

• Central exclusive production of $\eta_c$ and $\chi_{c0}$ in the light-front k$_{\perp}$-factorization approach

  Izabela Babiarz, Roman Pasechnik, Wolfgang Schäfer, Antoni Szczurek

  SciPost Phys. Proc. 8, 118 (2022) · published 13 July 2022 | Toggle abstract · pdf

  We study the exclusive production of $J^{PC}=0^{++}, 0^{--}$ charmonium states in proton-proton collisions at the LHC energies. The amplitudes for $g^*g^*→\chi_{c0}$ as well as for$ gg→\eta_c$ mechanisms are derived in the kT-factorization approach. The $pp \to pp\eta_c$ reaction is discussed for the first time. We observe a substantial contribution from the nonperturbative domain of gluon virtualities, especially for $\eta_c$ production. To model the nonperturbative region better, we utilize models of the unintegrated gluon distribution based on parametrizations of the color dipole cross-section.

• Central exclusive diffractive production of axial-vector $f_{1}$ mesons in proton-proton collisions

  Piotr Lebiedowicz, Josef Leutgeb, Otto Nachtmann, Anton Rebhan, Antoni Szczurek

  SciPost Phys. Proc. 8, 121 (2022) · published 13 July 2022 | Toggle abstract · pdf

  Exclusive production of axial-vector $f_{1}(1285)$ meson in proton-proton collisions via pomeron-pomeron fusion within the tensor-pomeron approach is discussed. Two ways to construct the pomeron-pomeron-$f_{1}$ coupling are presented. We adjust the parameters of our model to the WA102 experimental data and compare with predictions of the Sakai-Sugimoto model. Predictions for LHC experiments are given.

• Energy-Momentum Tensor Form Factors in QED

  Simone Rodini, Andreas Metz, Barbara Pasquini

  SciPost Phys. Proc. 8, 122 (2022) · published 13 July 2022 | Toggle abstract · pdf

  We present the results for the Energy-Momentum Tensor (EMT) form factor D(t) at oneloop accuracy in quantum electrodynamics for an electron state. We report the the results in the case of both zero and nonzero photon mass. Moreover, individual electron and photon contributions to the EMT are investigated.

• What do DVCS data tell us about TCS observables?

  O. Grocholski, H. Moutarde, B. Pire, P. Sznajder, J. Wagner

  SciPost Phys. Proc. 8, 070 (2022) · published 12 July 2022 | Toggle abstract · pdf

  Deeply virtual Compton scattering (DVCS) and timelike Compton scattering (TCS) leading twist amplitudes are intimately related thanks to their analytic properties as a function of $Q^2$. We exploit this feature to use Compton form factors previously extracted from available DVCS data and derive data-driven predictions for TCS observables to be measured in near future experiments. Our results quantitatively illustrate the complementarity of DVCS and TCS experiments.

• 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.

• Intermittency analysis of charged particles generated in Xe-Xe~collisions at $\sqrt{s_{\rm{NN}}}$ = 5.44 TeV using the AMPT model

  Zarina Banoo, Ramni Gupta

  SciPost Phys. Proc. 15, 010 (2024) · published 2 April 2024 | Toggle abstract · pdf

  The multiplicity fluctuations are sensitive to QCD phase transition and to the presence of critical point in QCD phase diagram. At critical point a system undergoing phase transition is characterized by large fluctuations in the observables which is an important tool to understand the dynamics of particle production in heavy-ion interactions and phase changes. Multiplicity fluctuations of produced particles is an important observable to characterize the evolving system. Using scaling exponent obtained from the normalized factorial moments of the number of charged hadrons in the two dimensional ($\eta,\phi$) phase space, one can learn about the dynamics of system created in these collisions. Events generated using Xe-Xe collisions at $\sqrt{s_{\rm{NN}}} = 5.44 $ TeV with string-melting (SM) version of the AMPT model are analyzed and the scaling exponent $(\nu)$ for various $p_T$ intervals is determined. It is observed that the calculated value of $\nu$ is larger than the universal value 1.304, as is obtained from Ginzburg-Landau theory for second order phase transition. Here we will also present the results of the dependence of the scaling exponent on the transverse momentum bin width.

• High-energy logarithmic corrections to the QCD component of same-sign W-pair production

  Jeppe R. Andersen, Bertrand Ducloué, Conor Elrick, Andreas Maier, Graeme Nail, Jennifer M. Smillie

  SciPost Phys. Proc. 8, 129 (2022) · published 13 July 2022 | Toggle abstract · pdf

  We describe the calculation of the QCD contribution to same-sign $W$-pair production, $pp\to e^\pm \nu_e \mu^\pm \nu_\mu jj$, resumming all contributions scaling as $\alpha_W^4 \alpha_s^{2+k}\log^k(\hat s/p_\perp^2)$ [arXiv:2107.06818]. These leading logarithmic contributions are enhanced by typical cuts used for Vector Boson Scattering (VBS) studies. We show that while the cross sections are little affected by these corrections, other more exclusive observables relevant for experimental studies are affected more significantly.

• $\Lambda$ 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.

• Opportunities for inclusive diffraction at EIC

  Wojciech Slominski, Nestor Armesto, Paul R. Newman, Anna Stasto

  SciPost Phys. Proc. 8, 069 (2022) · published 12 July 2022 | Toggle abstract · pdf

  The possibilities for inclusive diffraction in the Electron Ion Collider, EIC, in the US, are analyzed. We find that thanks to the excellent forward proton tagging, the EIC will be able to access a wider kinematical range of longitudinal momentum fraction and momentum transfer of the leading proton than at HERA. This opens up the possibility to measure subleading diffractive exchanges. The extended $t$-range would allow the precise extraction of 4-dimensional reduced cross section in diffraction. In addition, the varying beam energy setups at the EIC would allow for precise measurements of the longitudinal diffractive structure function.