Physics Commons^™

Deeply Learning Deep Inelastic Scattering Kinematics, Markus Diefenthaler, Abdullah Farhat, Andrii Verbytskyi, Yuesheng Xu

Mathematics & Statistics Faculty Publications

We study the use of deep learning techniques to reconstruct the kinematics of the neutral current deep inelastic scattering (DIS) process in electron–proton collisions. In particular, we use simulated data from the ZEUS experiment at the HERA accelerator facility, and train deep neural networks to reconstruct the kinematic variables Q² and x. Our approach is based on the information used in the classical construction methods, the measurements of the scattered lepton, and the hadronic final state in the detector, but is enhanced through correlations and patterns revealed with the simulated data sets. We show that, with the appropriate selection …

Top-Quark Pair Hadroproduction In Association With A Heavy Boson At Nlo+Nnll Including Ew Corrections, Alessandro Broggio, Andrea Ferroglia, Rikkert Frederix, Davide Pagani, Benjamin D. Pecjak, Ioannis Tsinikos

Publications and Research

This work studies the associated production of a top-quark pair with a W, Z, or Higgs boson at the LHC. Predictions for the total cross sections as well as for several differential distributions of the massive particles in the final state are provided. These predictions, valid for the LHC operating at 13 TeV, include without any approximation all the NLO electroweak and QCD contributions of O(αⁱ_sα^j+1) with i + j = 2, 3. In addition, the predictions presented here improve upon the NLO QCD results by adding the effects of soft gluon emission …

Commissioning Of The Large Angle Beamstrahlung Monitor At Superkekb, Salvatore Di Carlo

Wayne State University Dissertations

The Large Angle Beamstrahlung Monitor (LABM) is a device capable to monitor

the beam-beam collisions. The LABM measures the beamstrahlung light emitted

at large angle during the collisions of electron and positron beams. The properties

of the beamstrahlung, spectrum and polarization, are fundamentally related to the

size and relative position of the beams. Measuring the beamstrahlung, the LABM

delivers information about the size of the beams and their relative position at the

interaction point. The LABM will be part of the instrumentation of SuperKEKB,

a new e+e− collider that aims to reach the world record luminosity of 8×10^35 cm^-2 s^-1. …

Beam-Energy-Dependent Two-Pion Interferometry And The Freeze-Out Eccentricity Of Pions Measured In Heavy Ion Collisions At The Star Detector, L. Adamczyk, J.K. Adkins, G. Agakishiev, M.M. Aggarwal, Z. Ahammed, I. Koralt, Star Collaboration

Physics Faculty Publications

We present results of analyses of two-pion interferometry in Au + Au collisions at root s(NN) = 7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV measured in the STAR detector as part of the BNL Relativistic Heavy Ion Collider Beam Energy Scan program. The extracted correlation lengths (Hanbury-Brown-Twiss radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass (m(T)) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to …

Initial Conditions In High-Energy Collisions, Elena Petreska

Dissertations, Theses, and Capstone Projects

This thesis is focused on the initial stages of high-energy collisions in the saturation regime. We start by extending the McLerran-Venugopalan distribution of color sources in the initial wave-function of nuclei in heavy-ion collisions. We derive a fourth-order operator in the action and discuss its relevance for the description of color charge distributions in protons in high-energy experiments. We calculate the dipole scattering amplitude in proton-proton collisions with the quartic action and find an agreement with experimental data. We also obtain a modification to the fluctuation parameter of the negative binomial distribution of particle multiplicities in proton-proton experiments. The result …

Beam-Energy Dependence Of Charge Separation Along The Magnetic Field In Au + Au Collisions At Rhic, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, A. Banerjee, D. R. Beavis, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, H. Bichsel, M. Zyzak, Et Al., Star Collaboration

Physics Faculty Publications

Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with …

Third Harmonic Flow Of Charged Particles In Au + Au Collisions At √ S Nn = 200 Gev, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, Av. V. Alakhverdyants, I. Alekseev, S. Bültmann, I. Koraly, Star Collaboration

Physics Faculty Publications

We report measurements of the third harmonic coefficient of the azimuthal anisotropy, v₃, known as triangular flow. The analysis is for charged particles in Au+Au collisions at √sNN=200 GeV, based on data from the STAR experiment at the BNL Relativistic Heavy Ion Collider. Two-particle correlations as a function of their pseudorapidity separation are fit with narrow and wide Gaussians. Measurements of triangular flow are extracted from the wide Gaussian, from two-particle cumulants with a pseudorapidity gap, and also from event plane analysis methods with a large pseudorapidity gap between the particles and the event plane. These results are …

Next-To-Next-To-Leading Soft-Gluon Corrections For The Top Quark Cross Section And Transverse Momentum Distribution, Nikolaos Kidonakis

Faculty and Research Publications

I present results for top quark production in hadronic collisions at LHC and Tevatron energies. The soft-gluon corrections to the differential cross section are resummed at next-to-next-to-leading-logarithm accuracy via the two-loop soft anomalous dimension matrices. Approximate next-to-next-to-leading-order differential and total cross sections are calculated. Detailed theoretical predictions are shown for the t (t) over bar cross section and the top quark p(T) distribution at the Tevatron and the LHC.

Two-Loop Soft Anomalous Dimensions And Next-To-Next-To-Leading-Logarithm Resummation For Heavy Quark Production, Nikolaos Kidonakis

Faculty and Research Publications

I present results for two-loop soft anomalous dimensions for heavy quark production which control soft-gluon resummation at next-to-next-to-leading-logarithm accuracy. I derive an explicit expression for the exact result and study it numerically for top quark production via e(+) e(-) -> t (t) over bar t, and I construct a surprisingly simple but very accurate approximation. I show that the two-loop soft anomalous dimensions with massive quarks display a simple proportionality relation to the one-loop result only in the limit of vanishing quark mass. I also discuss the extension of the calculation to single top and top pair production in hadron …

Higher-Order Soft Gluon Corrections In Single Top Quark Production At The Cern Lhc, Nikolaos Kidonakis

Faculty and Research Publications

I present a calculation of soft-gluon corrections to single top-quark production in pp collisions at the LHC via the standard model partonic processes in the t and s channels and associated top quark and W boson production. Higher-order soft-gluon corrections through next-to-next-to-next-to-leading order (NNNLO) are calculated at next-to-leading logarithmic (NLL) accuracy. The soft-gluon corrections in the s channel and in tW production are large and dominant, while in the t channel they are not a good approximation of the complete QCD corrections.

Single Top Quark Production At The Fermilab Tevatron: Threshold Resummation And Finite-Order Soft Gluon Corrections, Nikolaos Kidonakis

Faculty and Research Publications

I present a calculation of threshold soft-gluon corrections to single top-quark production in p(p) collisions via all partonic processes in the t and s channels and via associated top quark and W boson production. The soft-gluon corrections are formally resummed to all orders, and finite-order expansions of the resummed cross section are calculated through next-to-next-to-next-to-leading-order (NNNLO) at next-to-leading logarithmic (NLL) accuracy. Numerical results for single top-quark production at the Tevatron are presented, including the dependence of the cross sections on the top-quark mass and on the factorization and renormalization scales. The threshold corrections in the t channel are small while …