G. Schnell
A5114375345- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle Accelerators and Free-Electron Lasers
- Neutrino Physics Research
- Computational Physics and Python Applications
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Black Holes and Theoretical Physics
- Dark Matter and Cosmic Phenomena
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Medical Imaging Techniques and Applications
- Nuclear physics research studies
- Astrophysics and Cosmic Phenomena
- Crystallography and Radiation Phenomena
- Radiation Detection and Scintillator Technologies
- Cosmology and Gravitation Theories
- Cold Atom Physics and Bose-Einstein Condensates
- Physics of Superconductivity and Magnetism
- X-ray Spectroscopy and Fluorescence Analysis
- Distributed and Parallel Computing Systems
- Particle accelerators and beam dynamics
- Gamma-ray bursts and supernovae
University of the Basque Country
2015-2024
Ikerbasque
2014-2023
Laboratoire d’Annecy de Physique des Particules
2018-2023
Institut National de Physique Nucléaire et de Physique des Particules
2018-2023
University of Michigan–Ann Arbor
2023
Centre National de la Recherche Scientifique
2018-2023
University of Cincinnati
2013-2023
Thomas Jefferson National Accelerator Facility
2023
RWTH Aachen University
2023
Rutherford Appleton Laboratory
2023
This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on structure and interactions gluon-dominated matter, with intent to articulate it broader nuclear community. It was commissioned by managements Brookhaven National Laboratory (BNL) Thomas Jefferson Accelerator Facility (JLab) objective presenting a summary scientific opportunities goals EIC as follow-up 2007 NSAC Long Range plan. document is culmination community-wide effort in following series workshops...
We provide a concise overview on transverse momentum dependent (TMD) parton distribution functions, their application to topical issues in high-energy physics phenomenology, and theoretical connections with QCD resummation, evolution factorization theorems. illustrate the use of TMDs via examples multi-scale problems hadronic collisions. These include q_T spectra Higgs vector bosons for low q_T, azimuthal correlations production multiple jets associated heavy at large jet masses. discuss...
This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on structure and interactions gluon-dominated matter, with intent to articulate it broader nuclear community. It was commissioned by managements Brookhaven National Laboratory (BNL) Thomas Jefferson Accelerator Facility (JLab) objective presenting a summary scientific opportunities goals EIC as follow-up 2007 NSAC Long Range plan. document is culmination community-wide effort in following series workshops...
An overwhelming number of theoretical predictions for hadron colliders require parton distribution functions (PDFs), which are an important ingredient theory infrastructure the next generation high-energy experiments.This whitepaper summarizes status and future prospects determination high-precision PDFs applicable in a wide range energies experiments, particular precision tests Standard Model new physics searches at high-luminosity Large Hadron Collider Electron-Ion Collider.We discuss...
The azimuthal cos{\phi} and cos2{\phi} modulations of the distribution hadrons produced in unpolarized semi-inclusive deep-inelastic scattering electrons positrons off hydrogen deuterium targets have been measured HERMES experiment. For first time these were determined a four-dimensional kinematic space for positively negatively charged pions kaons separately, as well unidentified hadrons. These dependences are sensitive to transverse motion polarization quarks within nucleon via, e.g.,...
Beam-helicity and beam-charge asymmetries in the hard exclusive leptoproduction of real photons from an unpolarised hydrogen target by a 27.6 GeV lepton beam are extracted HERMES data set 2006-2007 using missing-mass event selection technique. The asymmetry amplitudes this more precise than those earlier 1996-2005 previously analysed same manner HERMES. results two sets compatible with each other. Results these combined constitute most amplitude measurements made kinematic region
A bstract comprehensive set of azimuthal single-spin and double-spin asymmetries in semi-inclusive leptoproduction pions, charged kaons, protons, antiprotons from transversely polarized protons is presented. These include the previously published HERMES results on Collins Sivers asymmetries, analysis which has been extended to also an extraction a three-dimensional kinematic binning enlarged phase space. They are complemented by corresponding for remaining four allowed one-photon-exchange...
An earlier extraction from the HERMES experiment of polarization-averaged parton distribution strange quarks in nucleon has been reevaluated using final data on multiplicities charged kaons semi-inclusive deep-inelastic scattering obtained with a kinematically more comprehensive method correcting for experimental effects. General features are confirmed, but rise at low x is less pronounced than previously reported.
We present the complete cross-section for production of unpolarized hadrons in semi-inclusive deep-inelastic scattering up to power-suppressed ${\cal O}(1/Q^2)$ terms Wandzura--Wilczek-type approximation which consists systematically assuming that $\bar{q}gq$--terms are much smaller than $\bar{q}q$--correlators. compute all twist-2 and twist-3 structure functions corresponding asymmetries, discuss applicability approximations on basis available data. make predictions can be tested by data...
The European Particle Physics Strategy Update (EPPSU) process takes a bottom-up approach, whereby the community is first invited to submit proposals (also called inputs) for projects that it would like see realised in near-term, mid-term and longer-term future. National inputs as well from Laboratories are also an important element of process. All these then reviewed by Preparatory Group (PPG), whose role organize Symposium around submitted ideas prepare discussion on importance merits...
The physics of high-energy colliders relies on the knowledge different non-perturbative parton correlators, such as distribution functions, that encode information universal hadron structure and are thus main building blocks any factorization theorem underlying process in collision. These functions given terms gauge-invariant light-front operators, they non-local both space real time, intractable by standard lattice techniques due to well-known sign problem. In this paper, we propose a...
Physics Beyond Colliders is an exploratory study aimed at exploiting the full scientific potential of CERN's accelerator complex and its infrastructure in next two decades through projects complementary to LHC, HL-LHC other possible future colliders. These should target fundamental physics questions that are similar spirit those addressed by high-energy colliders, but require different types beams experiments. A kick-off workshop held September 2016 identified a number areas interest working...
Data from high-energy physics (HEP) experiments are collected with significant financial and human effort mostly unique. An inter-experimental study group on HEP data preservation long-term analysis was convened as a panel of the International Committee for Future Accelerators (ICFA). The formed by large collider-based investigated technical organisational aspects preservation. intermediate report released in November 2009 addressing general issues HEP. This paper includes extends report. It...
Measurements of the production forward jets from transversely polarized proton collisions at s=500 GeV conducted Relativistic Heavy Ion Collider (RHIC) are reported. Our measured jet cross section is consistent with hard scattering expectations. analyzing power for small and positive, provides constraints on Sivers functions that related to partonic orbital angular momentum through theoretical models.
This volume is a collection of contributions for the 7-week program "Probing Nucleons and Nuclei in High Energy Collisions" that was held at Institute Nuclear Theory Seattle, WA, USA, from October 1 until November 16, 2018. The dedicated to physics Electron Ion Collider (EIC), world's first polarized electron-nucleon (ep) electron-nucleus (eA) collider be constructed USA. These proceedings are organized by chapters, corresponding weeks program: Week I, Generalized parton distributions; II,...
Exclusive electroproduction of $$\omega $$ mesons on unpolarized hydrogen and deuterium targets is studied in the kinematic region $$Q^2> 1.0$$ GeV $$^2$$ , 3.0 $$< W <$$ 6.3 GeV, $$-t'< 0.2$$ . Results angular distribution meson, including its decay products, are presented. The data were accumulated with HERMES forward spectrometer during 1996–2007 running period using 27.6 longitudinally polarized electron or positron beam HERA. determination virtual-photon longitudinal-to-transverse...
We derive an inequality for the distribution of quarks with nonzero orbital angular momentum, and thus demonstrate, in a model-independent way, that nonvanishing anomalous magnetic moment requires both size target as well presence wave function components quark momentum ${L}_{z}^{q}>0$.
The Experimental Cavern North 3 (ECN3) is an underground experimental cavern on the CERN Pr\'evessin site. ECN3 currently hosts NA62 experiment, with a physics programme devoted to rare kaon decays and searches of hidden particles approved until Long Shutdown (LS3). Several options are proposed longer term in order make best use worldwide unique potential high-intensity/high-energy proton beam extracted from Super Proton Synchrotron (SPS) ECN3. current status their study by Physics Beyond...
A measurement of beam-helicity asymmetries for single-hadron production in deep-inelastic scattering is presented. Data from the 27.6 GeV electrons and positrons off gaseous hydrogen deuterium targets were collected by HERMES experiment. The are presented separately as a function Bjorken scaling variable, hadron transverse momentum, fractional energy charged pions kaons well protons anti-protons. These also three aforementioned kinematic variables simultaneously.
A comprehensive collection of results on longitudinal double-spin asymmetries is presented for charged pions and kaons produced in semi-inclusive deep-inelastic scattering electrons positrons the proton deuteron, based full HERMES data set. The dependence hadron transverse momentum azimuthal angle extends sensitivity to flavor structure nucleon beyond distribution functions accessible collinear framework. No strong those variables observed. In addition, charge-difference asymmetry presented,...
A Comment on the recently published reevaluation of polarization-averaged parton distribution strange quarks in nucleon using final data multiplicities charged kaons semi-inclusive deep-inelastic scattering is reviewed. Important features comparison one-dimensional projections multidimensional HERMES are pointed out. test leading-order extraction xS(x) difference between charged-kaon repeated. The results consistent with predictions within uncertainties input data, and do not invalidate...
This report summarises the main findings of QCD Working Group in CERN Physics Beyond Colliders Study.
A comprehensive set of azimuthal single-spin and double-spin asymmetries in semi-inclusive leptoproduction pions, charged kaons, protons, antiprotons from transversely polarized protons is presented. These include the previously published HERMES results on Collins Sivers asymmetries, analysis which has been extended to also an extraction a three-dimensional kinematic binning enlarged phase space. They are complemented by corresponding for remaining four allowed one-photon-exchange...