Article
Physics, Particles & Fields
Renaud Boussarie, Heikki Mantysaari, Farid Salazar, Bjorn Schenke
Summary: This study focuses on computing the differential yield for quark anti-quark dijet production in high-energy electron-proton and electron-nucleus collisions at small x. It compares results between the Color Glass Condensate (CGC) and the improved TMD (ITMD) frameworks, highlighting genuine higher saturation contributions. The study provides numerical estimates for inclusive dijet production at the future Electron-Ion Collider, aiming to allow detailed experimental study of kinematic power corrections and genuine gluon saturation effects.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
V. M. Braun, K. G. Chetyrkin, B. A. Kniehl
Summary: In this study, the short-distance expansion of the product of two gluon field strength tensors connected by a straight-line-ordered Wilson line is considered. The three-loop coefficient functions of the scalar operators in the operator product expansion up to dimension four are calculated, and the three-loop anomalous dimension of the nonlocal two-gluon operator is obtained as a by-product.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Arno Vanthieghem, Atri Bhattacharya, Rami Oueslati, Jean-Rene Cudell
Summary: The study shows that high-energy collider data can be best fitted to different scattering cross sections using either eikonal or U-matrix schemes. Both schemes can be generalized by adding parameters, but this only results in marginal improvements to the fits. Estimates for the ratio of the real part to the imaginary part of the elastic amplitude, rho, are provided in the research.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Jiawei Zhu, Daekyoung Kang, Tanmay Maji
Summary: Angularity is an event-shape observable that can be measured in deep-inelastic scattering, allowing interpolation between thrust and broadening with its continuous parameter a. Factorizing the cross section using soft-collinear effective theory is valid in a wide range below and above the thrust region but not in the broadening limit. Resummation of large logs for angularity allows predictions at various values of a at next-to-next-to-leading log accuracy.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Markus A. Ebert, Bernhard Mistlberger, Gherardo Vita
Summary: In this study, we computed the unpolarized quark and gluon transverse-momentum dependent fragmentation functions at next-to-next-to-next-to-leading order in perturbative QCD. Our calculation is based on a relation between the TMDFF and the limit of semi-inclusive deep inelastic scattering cross section where all final-state radiation becomes collinear to the detected hadron. The results obtained agree with a recent independent calculation by Luo et al.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Isobel Kolbe, Kaushik Roy, Farid Salazar, Bjorn Schenke, Raju Venugopalan
Summary: The study computes the differential cross-section for inclusive prompt photon+quark production in deeply inelastic scattering of electrons off nuclei at small x, and observes a systematic suppression and broadening pattern of the back-to-back peak in the relative azimuthal angle distribution as the saturation scale is increased. The research also suggests that photon+jet final states at high energies in e + A DIS are a promising channel for exploring gluon saturation that is complementary to inclusive and diffractive dijet production.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Richard Ruiz, Antonio Costantini, Fabio Maltoni, Olivier Mattelaer
Summary: This study re-evaluates the validity of using W and Z parton distribution functions (PDFs) at leading order in 2 -> n processes in a muon collider, and investigates a variety of 2 -> n processes. To conduct this study, the Effective Vector Boson Approximation is implemented in the Monte Carlo event generator, laying the foundation for developing matrix-element matching prescriptions involving electroweak parton showers and renormalized electroweak PDFs.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Daniele Paolo Anderle, Tie-Jiun Hou, Hongxi Xing, Mengshi Yan, C-P Yuan, Yuxiang Zhao
Summary: One of the main goals of the proposed Electron-Ion Collider in China is to understand how sea quarks behave inside a nucleon. This will be achieved through analyzing data from different collisions to reduce uncertainties in parton helicity distributions.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Umberto D'Alesio, Luca Maxia, Francesco Murgia, Cristian Pisano, Sangem Rajesh
Summary: This study investigates the polar and azimuthal decay angular distributions of J/ψ mesons produced in semi-inclusive, deep-inelastic electron-proton scattering. The research adopts the framework of nonrelativistic QCD and focuses on the cos 2 phi azimuthal decay asymmetry as well as proposes a novel experiment for the extraction of an unknown parton density. By determining the perturbative tails of the shape functions and finding them to be independent of the J/ψ polarization, the study contributes to a better understanding of the quarkonium formation mechanism.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
K. B. Chen, J. P. Ma, X. B. Tong
Summary: The study of factorization in Semi-Inclusive Deep Inelastic Scattering includes predictions using fracture functions and diffractive parton distributions. Results are useful for modeling fracture functions and handling resummation of large logarithm of the transverse momentum in collinear factorization.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Yiannis Makris, Felix Ringer, Wouter J. Waalewijn
Summary: The paper presents a framework for precise predictions of hadron transverse momentum relative to the thrust axis in e(+)e(-) collisions, enabling extraction of TMD fragmentation functions from recent experiments. By considering the interplay between hadron transverse momentum and thrust event shape cut, the analysis identifies three kinematic regions and provides ingredients for joint resummation of transverse momentum and thrust spectrum at NNLL accuracy. The inclusion of non-global logarithms and discussion of alternative measurements in e(+)e(-) collisions are also discussed.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Zhong-Bo Kang, Jared Reiten, Ding Yu Shao, John Terry
Summary: Using Soft-Collinear Effective Theory, this study develops a transverse-momentum-dependent factorization formalism for heavy flavor dijet production in polarized-proton-electron collisions. By considering heavy flavor mass corrections and comparing theoretical predictions with and without finite quark masses, it is found that heavy flavor mass effects can significantly impact the predicted asymmetry for gluon Sivers asymmetry in charm and bottom dijet production at the future Electron-Ion Collider.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Enrico Lunghi, Nathan Sherrill, Adam Szczepaniak, Alexandre Vieira
Summary: The study investigates quark-sector Lorentz violation in Drell-Yan dilepton production with Z-boson exchange, demonstrating how the chiral nature of weak interactions allows for the study of parity-violating and spin-dependent effects using unpolarized initial states. Constraints on Lorentz violation coefficients for the first two generations of quarks are established based on measurements from the Large Hadron Collider.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
S. Kumano, Qin-Tao Song
Summary: This work explores the twist-2 relation and sum rule for tensor-polarized parton distribution functions, providing valuable insights for studying spin-1 hadrons and separating twist-2 components from higher-twist terms. The existence of twist-3 multiparton distribution functions for tensor-polarized spin-1 hadrons is also highlighted, showcasing the potential for probing multiparton correlations in these particles. Furthermore, upcoming experimental projects focusing on spin-1 hadrons' spin structure indicate a growing interest in this area of physics.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Hong-Fei Zhang, Xue-Mei Mo
Summary: The study calculates eta(c) meson leptoproduction for the first time within the nonrelativistic QCD framework and finds that the color-singlet channel contributes significantly to experimental conditions despite being suppressed relative to the color-octet channels. Differential cross section data is provided as a reference for future studies, and the study also investigates scale dependence and long-distance-matrix-element dependence.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Multidisciplinary
Liliana Apolinario, Jose Guilherme Milhano, Gavin P. Salam, Carlos A. Salgado
PHYSICAL REVIEW LETTERS
(2018)
Article
Physics, Particles & Fields
Frederic A. Dreyer, Gavin P. Salam, Gregory Soyez
JOURNAL OF HIGH ENERGY PHYSICS
(2018)
Article
Physics, Nuclear
Liliana Apolinario, Guilherme Milhano, Carlos A. Salgado, Gavin Salam
Article
Physics, Nuclear
Gavin P. Salam
Article
Physics, Nuclear
Harry Arthur Andrews, Liliana Apolinario, Redmer Alexander Bertens, Christian Bierlich, Matteo Cacciari, Yi Chen, Yang-Ting Chien, Leticia Cunqueiro Mendez, Michal Deak, David d'Enterria, Fabio Dominguez, Philip Coleman Harris, Krzysztof Kutak, Yen-Jie Lee, Yacine Mehtar-Tani, James Mulligan, Matthew Nguyen, Chang Ning-Bo, Dennis Perepelitsa, Gavin Salam, Martin Spousta, Jose Guilherme Milhano, Konrad Tywoniuk, Marco Van Leeuwen, Marta Verweij, Victor Vila, Urs A. Wiedemann, Korinna C. Zapp
JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS
(2020)
Article
Physics, Particles & Fields
Gionata Luisoni, Pier Francesco Monni, Gavin P. Salam
Summary: Hadronisation corrections are crucial for extracting the strong coupling constant from event-shape distributions at lepton colliders. The leading non-perturbative correction in the symmetric three-jet limit for the C parameter differs significantly from the known result in the two-jet limit. Most interpolation choices in the region between the 2 and 3-jet limits increase the extracted alpha s by up to 4%, revealing a new perspective on the discrepancy between certain event-shape alpha s fits and the world average.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Particles & Fields
Keith Hamilton, Rok Medves, Gavin P. Salam, Ludovic Scyboz, Gregory Soyez
Summary: This work focuses on correcting the subleading-colour contributions to leading and next-to-leading logarithms (NLL) for a range of observables in final-state showers. Two simple and computationally efficient prescriptions are presented to address the issue, showing correct full colour NLL terms for global observables and multiplicities. Despite remaining subleading colour issues at NLL for non-global observables, one of the schemes reproduces the correct full-colour matrix-element for any number of energy-ordered commensurate-angle pairs of emissions.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Fabrizio Caola, Frederic A. Dreyer, Ross W. McDonald, Gavin P. Salam
Summary: Top-quark pair production is crucial to LHC physics, with different event topologies characterized by a range of variables. In addition to the back-to-back topology, some events involve gluon splitting to t (t) over bar pairs. Additional features of events with large t (t) over bar invariant mass have significant experimental and theoretical implications.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Gavin P. Salam, Emma Slade
Summary: Fixed-order perturbative calculations for two-body decay processes at colliders exhibit sensitivity to unphysically low momentum scales and poor convergence, especially in the case of H -> γγ in gluon fusion. By making simple modifications to fiducial cuts, such as replacing linear dependence with quadratic dependence, significant improvements in perturbative expansion behavior can be achieved. More sophisticated cuts can even achieve Higgs p(t)-independent acceptance at low p(t) with various advantages.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Paolo Nason, Gavin P. Salam
Summary: The proposed approach combines the features of the MC@NLO and KrkNLO methods to achieve a combination of NLO and parton shower calculations. It aims to provide applicability to general showers, positive-weight events, and attribute all showering to the parton shower code. This is achieved through multiplicative and accumulative matching in different phase space regions.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Multidisciplinary Sciences
Gavin P. Salam, Lian-Tao Wang, Giulia Zanderighi
Summary: The discovery of the Higgs boson was a significant milestone that opened up new avenues of research. The role of the Higgs field in the Standard Model of particle physics has a profound impact on our world. Over the past ten years, insights into Higgs physics have been gained, but there are still many unanswered questions.
Article
Physics, Particles & Fields
Melissa van Beekveld, Silvia Ferrario Ravasio, Keith Hamilton, Gavin P. Salam, Alba Soto-Ontoso, Gregory Soyez, Rob Verheyen
Summary: We conducted extensive tests on the NLL accuracy of the PanScales parton showers and compared them with various calculations. The results show that traditional shower simulations have significant NLL errors in some cases.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Melissa van Beekveld, Silvia Ferrario Ravasio, Gavin P. Salam, Alba Soto-Ontoso, Gregory Soyez, Rob Verheyen
Summary: In this paper, we present tests of the PanScales parton showers for colour singlet production at fixed order, including the treatment of momentum imbalances from initial-state branching and the full colour handling for soft-collinear emissions and spin correlations.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Keith Hamilton, Alexander Karlberg, Gavin P. P. Salam, Ludovic Scyboz, Rob Verheyen
Summary: This study examines the relationship between NLO matching and NLL parton showers, focusing on the simplest case of gamma* and Higgs-boson decays to qq and gg. The study finds that matching can enhance the shower to achieve NNDL accuracy for global event-shape observables and the two-jet rate. Various methods, including multiplicative matrix-element corrections and MC@NLO and POWHEG-style matching, are explored and shown to bring NNDL accuracy. The study combines analytic and numerical components and also considers some phenomenological aspects.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Andrew Lifson, Gavin P. Salam, Gregory Soyez
JOURNAL OF HIGH ENERGY PHYSICS
(2020)