Publications

Order by: publication date number of citations

• QCD factorization for hadronic quarkonium production at high $p_T$

  Kyle Lee, Jian-Wei Qiu, George Sterman, Kazuhiro Watanabe

  SciPost Phys. Proc. 8, 143 (2022) · published 14 July 2022 | Toggle abstract · pdf

  Heavy quarkonium production at high transverse momentum ($p_T$) in hadronic collisions is explored in the QCD factorization approach. We find that the leading power in the $1/p_T$ expansion is responsible for high $p_T$ regime, while the next-to-leading power contribution is necessary for the low $p_T$ region. We present the first numerical analysis of the scale evolution of coupled twist-2 and twist-4 fragmentation functions (FFs) for heavy quarkonium production and demonstrate that the QCD factorization approach is capable of describing the $p_T$ spectrum of hadronic $J/\psi$ production at the LHC.

  5 citations

• Prospects for diffractive dijet photoproduction at the EIC

  V. Guzey, M. Klasen

  SciPost Phys. Proc. 8, 142 (2022) · published 14 July 2022 | Toggle abstract · pdf

  We discuss the prospects of diffractive dijet photoproduction at the EIC to distinguish different fits of diffractive proton PDFs, different schemes of factorization breaking, to determine diffractive nuclear PDFs and pion PDFs from leading neutron production.

• Inclusive and diffractive dijet photoproduction in ultraperipheral heavy ion collisions at the LHC

  V. Guzey, M. Klasen

  SciPost Phys. Proc. 8, 141 (2022) · published 14 July 2022 | Toggle abstract · pdf

  We calculate the cross section of inclusive dijet photoproduction in ultraperipheral collisions (UPCs) of heavy ions at the CERN Large Hadron Collider using next-to-leading order perturbative QCD and demonstrate that it provides a good description of the ATLAS data. We study the role of this data in constraining nuclear parton distribution functions (nPDFs) using the Bayesian reweighting technique and find that it can reduce current uncertainties of nPDFs at small $x$ by a factor of 2. We also make predictions for diffractive dijet photoproduction in UPCs and examine its potential to shed light on the disputed mechanism of QCD factorization breaking in diffraction.

• 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.

• Phenomenological extraction of a universal TMD fragmentation function from single hadron production in $e^+ e^-$ annihilations

  M. Boglione, J.O. Gonzalez-Hernandez, A. Simonelli

  SciPost Phys. Proc. 8, 139 (2022) · published 14 July 2022 | Toggle abstract · pdf

  Factorizing the cross section for single hadron production in $e^+e^-$ annihilations, differential in $z_h$, $P_T$ and thrust, is a highly non trivial task. We have devised a factorization scheme that allows us to recast the $e^+e^- \to hX$ cross section in the convolution of a calculable hard coefficient and a universal Transverse Momentum Dependent (TMD) Fragmentation Function (FF). The predictions obtained from our NLO-LL perturbative computation, together with a simple ansatz to model the non-perturbative part of the TMD, are applied to the experimental measurements of the BELLE Collaboration for the phenomenological extraction of this process independent TMD FF.

  2 citations

• Comparison of $pp$ and $p \bar{p}$ differential elastic cross sections and observation of the exchange of a colorless $C$-odd gluonic compound

  C. Royon

  SciPost Phys. Proc. 8, 138 (2022) · published 14 July 2022 | Toggle abstract · pdf

  We describe the discovery of the colorless $C$-odd gluonic compound, the odderon, by the D0 and TOTEM Collaborations by comparing elastic differential cross sections in $pp$ and $p \bar{p}$ interactions at high energies.

• New 2- and 3-loop heavy flavor corrections to unpolarized and polarized deep-inelastic scattering

  Jakob Ablinger, Johannes Blümlein, Abilio De Freitas, Marco Saragnese, Carsten Schneider, Kay Schoenwald

  SciPost Phys. Proc. 8, 137 (2022) · published 14 July 2022 | Toggle abstract · pdf

  A survey is given on the new 2– and 3–loop results for the heavy flavor contributions to deep–inelastic scattering in the unpolarized and the polarized case. We also discuss related new mathematical aspects applied in these calculations.

• 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 of LHC dijet production in pp and pPb collisions on the nNNPDF2.0 nuclear PDFs

  Rabah Abdul Khalek

  SciPost Phys. Proc. 8, 135 (2022) · published 14 July 2022 | Toggle abstract · pdf

  We quantify the impact of LHC dijet production measurements on the nNNPDF2.0 nuclear PDFs in twofold. First, from a proton baseline based on NNPDF3.1 and augmented by pp dijet production measurements from ATLAS and CMS at 7 and 8 TeV. Second, from a new nNNPDF2.0 global analysis including the ratio of pPb to pp dijet spectra from CMS at 5 TeV. We show that as opposed to the CMS at 5 TeV absolute pp and pPb dijet spectra, the pPb/pp ratio is well described in a nPDFs fit and provides strong constraints on the gluon of lead.

  1 citation

• Nuclear matter effects on jet production at electron-ion colliders

  Hai Tao Li, Ze Long Liu, Ivan Vitev

  SciPost Phys. Proc. 8, 134 (2022) · published 14 July 2022 | Toggle abstract · pdf

  In these proceedings we report recent progress on understanding hadron and jet production in electron-nucleus collisions at the future Electron-Ion Collider [1,2]. These processes will play an essential role in the exploration of the partonic structure of nuclei and the study of parton shower evolution in strongly-interacting matter. We employ the framework of soft-collinear effective theory, generalized to include in-medium interactions, to present the first theoretical results for inclusive hadron and jet cross sections, as well as the jet charge modification in deep inelastic scattering on nuclei. We further demonstrate how to separate initial-state and final-state effects.

  1 citation