Conveners
WG4: QCD with Heavy Flavors and Hadronic Final States: WG4: Session #1 (...topic ...)
- Chiara Signorile
WG4: QCD with Heavy Flavors and Hadronic Final States: WG4: Session #2
- Brian Page (Brookhaven National Laboratory)
WG4: QCD with Heavy Flavors and Hadronic Final States: WG4: Session #3
- Chiara Signorile
WG4: QCD with Heavy Flavors and Hadronic Final States: WG4: Sessoin #6
- Brian Page (Brookhaven National Laboratory)
WG4: QCD with Heavy Flavors and Hadronic Final States: WG4: Session #7
- Chiara Signorile
WG4: QCD with Heavy Flavors and Hadronic Final States: WG4: Session #9
- Brian Page (Brookhaven National Laboratory)
The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.
A measurement of jet cross sections in the laboratory...
Semi-inclusive hadron production in deep-inelastic lepton-nucleon scattering (SIDIS) is an important probe of the quark flavor structure of the nucleon and of the fragmentation dynamics of quarks into hadrons. In case of longitudinally polarized beams, SIDIS is a powerful tool for resolving the quark flavor decomposition of the protonโs spin structure. I report on the recent calculation of the...
In deep-inelastic positron-proton scattering, the lepton-jet azimuthal angular asymmetry is measured using data collected with the H1 detector at HERA. When the average transverse momentum of the lepton-jet system, $\lvert \vec{P}_\perp \rvert $, is much larger than the total transverse momentum of the system, $\lvert \vec{q}_\perp \rvert$, the asymmetry between parallel and antiparallel...
The precision and reach of physics analyses at the LHC is often tied to the performance of hadronic object reconstruction & calibration, with any incremental gains in understanding & reduced uncertainties being impactful on ATLAS results. Recent refinements to the reconstruction and calibration procedures for jets & missing energy by the ATLAS collaboration has resulted in reduced...
Hadronic object reconstruction & classification is one of the most promising settings for cutting-edge machine learning and artificial intelligence algorithms at the LHC. In this contribution, highlights of ML/AI applications by ATLAS to QCD and boosted-object identification, MET reconstruction and other tasks will be presented.
The identification of jets containing b-hadrons is key to many physics analyses at the LHC, including measurements involving Higgs bosons or top quarks, and searches for physics beyond the Standard Model. In this contribution, the most recent enhancements in the capability of ATLAS to separate b-jets from jets stemming from lighter quarks will be presented. The improved performance originates...
A number of flagship analyses in the ATLAS experiment rely on real-time b-tagging to efficiently record data. In run 3, the jet and b-jet trigger was updated with state of the art machine learning, to reduce background rates and improve efficiency, while remaining within the constraints of the trigger hardware. We will discuss the design, optimization, deployment, and validation of the ATLAS...
We revisit the fragmentation processes $g\to\chi_{cJ}+g$, $g\to\eta_c+g$, $g\to J/\psi+g+g$ and propose and alternative method to regularize the infrared and collinear divergencies. We argue that the conventional technique (i.g., the dimensional regularization) are unphysical, as they expand the perturbation theory beyond its applicability limits. At the same time, the conventional...
In this talk, we present our extension of the concept of maximal quantum entanglement from proton structure to jet fragmentation in proton-proton collisions, establishing a connection between jet fragmentation functions and charged hadron multiplicity [1]. This relationship is tested using ATLAS data from the Large Hadron Collider, showing excellent agreement. As the first study to apply...
Ultraperipheral collisions of relativistic heavy ion beams lead to a diverse set of photon-nucleus (photonuclear) interactions. Measurements of particles produced in photonuclear reactions can shed light on the QCD dynamics of these novel, extremely asymmetric colliding systems, with energies between those available at RHIC and the LHC. Previous studies by ATLAS have characterized photonuclear...
In this talk, recent measurements of distributions sensitive to the underlying event, the hadronic activity observed in relationship with the hard scattering in the event, by the ATLAS experiment are presented. Underlying event observables like the average particle multiplicity and the transverse momentum sum are measured for Kaons as Lambda baryons as a function of the leading track-jet and...
In this presentation, I will discuss recent advancements in NNLO+PS predictions for top-quark pair production and decay within the MiNNLO framework. MiNNLO provides a robust method for incorporating next-to-next-to-leading order (NNLO) QCD corrections directly into fully differential predictions, offering unprecedented accuracy. This approach enables a consistent treatment of both production...
Studying heavy-flavour hadron properties provides a extensive tests for various QCD predictions as well as a means to probe the Standard Model validity. ATLAS experiment, being a general-purpose detector at LHC, is particularly successful in such measurements with final states involving muons, thanks to large collected integrated luminosity and precise muon reconstruction and triggering. This...
The Belle and Belle II experiments have collected a $1.4~\mathrm{ab}^{-1}$ sample of $e^+e^-$ collision data at centre-of-mass energies near the $\Upsilon(nS)$ resonances. These data include a 19.2 fb$^{-1}$ sample of data collected at centre-of-mass energies near the $\Upsilon(10753)$ resonance. We present several results related to the following processes: $e^+e-\to \Upsilon(nS)\eta$,...
The H1 Collaboration reports the first measurement of the 1-jettiness event shape observable $\tau_1^b$ in neutral-current deep-inelastic electron-proton scattering (DIS). The observable $\tau_1^b$ is equivalent to a thrust observable defined in the Breit frame. The data sample was collected at the HERA $ep$ collider in the years 2003--2007 with center-of-mass energy of $\sqrt{s}=319$ GeV,...
The H1 Collaboration at HERA reports the first measurement of groomed event shape observables in deep inelastic electron-proton scattering (DIS) at $\sqrt{s}=319$ GeV, using data recorded between the years 2003 and 2007 with an integrated luminosity of 351 pb$^{-1}$. Event shapes provide incisive probes of perturbative and non-perturbative QCD. Grooming techniques have been used for jet...
I report on recent progress in SHERPA's simulation of QCD processes in DIS and photo-production at current and future collider experiments.
The study of the production of single W and Z bosons at the LHC, inclusive and in association with jets, provides stringent tests of the electroweak theory and perturbative QCD. The ATLAS experiment has measured the W boson production cross section and the W-boson charge asymmetry as a function of lepton rapidity in special LHC runs with reduced instantaneous luminosity at 5 and 13 TeV....
Using modern machine learning, a measurement of all outgoing particles from high $Q^2$ electron-proton collisions is presented using data recorded with the H1 detector at HERA. The resulting differential cross section is unbinned and multi-dimensional, yet unfolded to the particle level. It thus allows for flexible reinterpretations.
Jet cross-section ratios between inclusive bins of jet multiplicity are measured differentially in variables that are sensitive to either the energy-scale or angular distribution of hadronic energy flow in the final state. Several improvements to the calibration of jets are described, which result in significant improvements in the overall jet energy scale uncertainty. The measurements are...
We determine the value of the strong coupling ฮฑ_s and study its running over a wide range of scales as probed by the dijet production process at hadron colliders. The analysis is performed using the complete next-to-next-to-leading order (NNLO) predictions in perturbative QCD and is based on dijet data published by ATLAS and CMS at center-of-mass energies of 7, 8, and 13 TeV. From a large...
Jets, the collimated streams of hadrons resulting from the fragmentation of highly energetic quarks and gluons, are some of the most commonly observed radiation patterns in hadron collider experiments. The distribution of quantum chromodynamic (QCD) radiation within jets is determined by complex processes, the production of showers of quarks and gluons and their subsequent recombination into...
We present calculations of higher-order QCD and electroweak (EW) corrections to the associated production of a top-antitop quark pair and a Z boson, i.e. $t{\bar t}Z$ production, in proton collisions. We find that the contributions from soft-gluon corrections are numerically dominant and large. We present approximate NNLO (aNNLO) and approximate N$^3$LO (aN$^3$LO) cross sections that include...
With a large momentum transfer, high energy lepton-hadron deep inelastic scattering induces both QCD and QED radiations. In this talk, we present the first NLO calculation of inclusive single hadron/jet production at large transverse momentum in lepton-hadron scattering in a joint QCD and QED factorization approach [1]. Both QCD and QED collision-induced radiation are treated equally and...
The Breit frame provides a natural frame to analyze lepton--proton scattering events. In this reference frame, the parton model hard interactions between a quark and an exchanged boson defines the coordinate system such that the struck quark is back-scattered along the virtual photon momentum direction. In Quantum Chromodynamics (QCD), higher order perturbative or non-perturbative effects can...
A recently completed calculation of next-to-next-to-leading QCD corrections to the weak radiative B-meson decay is going to be reported. Contrary to previous estimates of these corrections, no interpolation in the charm quark mass is necessary. Next, the current status of determining perturbative and non-perturbative contributions to the inclusive semileptonic B-meson decays is going to be discussed.
Employing the heavy quark expansion model with the kinetic scheme, we evaluate $\alpha_S(m_c^2)$, the strong coupling constant at the charm quark mass $m_c$ with data on inclusive semileptonic decays of charmed mesons. Using the experimental values of semileptonic decay widths of the $D^0$ and the $D^+$, the value of $\alpha_{s}(m_c^{2})$ is determined to be $0.445\pm0.009\pm0.114$, where the...
