katarzyna wichmann
(DESY)
28/04/2015, 08:30
WG1 Structure Functions and Parton Densities
A combination is presented of all inclusive deep inelastic cross sections measured by the H1 and ZEUS collaborations in neutral and charged current unpolarised ep scattering at HERA. The data correspond to a luminosity of about 1 fb-1 and span six orders of magnitude in negative four-momentum-transfer squared, Qยฒ, and Bjorken x. They include data taken at proton beam energies of 920, 820, 575...
Christopher Deans
(University of Edinburgh)
28/04/2015, 08:55
WG1 Structure Functions and Parton Densities
I will present NNPDF3.0, the first set of parton distributions determined with a methodology validated by a closure test. NNPDF3.0 uses a global dataset including HERA-II deep-inelastic inclusive cross-sections, the combined HERA charm data, jet production from ATLAS and CMS, vector boson rapidity and transverse momentum distributions from ATLAS, CMS and LHCb, W + c data from CMS and top quark...
C.-P. Yuan
(Michigan State University)
28/04/2015, 09:20
WG1 Structure Functions and Parton Densities
I review progress in the global PDF analysis by the CTEQ-TEA group.
Dr
Wally Melnitchouk
(Jefferson Lab)
28/04/2015, 09:45
WG1 Structure Functions and Parton Densities
We present preliminary results of a new global QCD analysis of PDFs
from the CTEQ-Jefferson Lab Collaboration (dubbed "CJ15"), which
includes several new data sets and recent theoretical developments.
In particular, we study the constraints from new D0 data on *W* boson
asymmetries on the *d/u* PDF ratio at large *x*, and, indirectly, on
the models of nuclear corrections in the deuteron. ...
Volodymyr myronenko
(DESY)
28/04/2015, 10:45
WG1 Structure Functions and Parton Densities
The new combined inclusive HERA cross sections were input to QCD
analyses at NNLO, NLO and LO providing a new set of parton
distribution functions, HERAPDF2.0. Besides the small experimental
uncertainties, model and parameterisation uncertainties were also
considered. The consistency of data and the QCD fit was tested for
variants of the fit such as the treatment of heavy flavour...
Ringaile Placakyte
(Hamburg University)
28/04/2015, 11:10
WG1 Structure Functions and Parton Densities
The uncertainties of protons parton distribution functions (PDFs) play a dominant role for the precision tests of the Standard Model (SM) and they also impact substantially the theory predictions of Beyond SM high mass production. We present the HERAFitter project which provides a unique open-source software framework for the determination of the proton's PDFs and for the interpretation of...
Pavel Starovoitov
(Deutsches Elektronen-Synchrotron (DE))
28/04/2015, 11:35
WG1 Structure Functions and Parton Densities
A method to facilitate the inclusion of collider data in the PDF fits, APPLGRID, has been extended to the NNLO accuracy. The method stores the matrix elements of the NNLO calculations to the look-up tables. This allows the a posteriori inclusion of the PDF sets and the strong coupling to the cross-section calculations.
Fred Stober
(KIT - Karlsruhe Institute of Technology (DE))
28/04/2015, 12:00
Dr
Aleksander Kusina
(LPSC Grenoble)
28/04/2015, 14:00
WG1 Structure Functions and Parton Densities
We present the first official release of the nCTEQ nuclear parton distribution functions with errors.
The main addition to the previous nCTEQ PDFs is the introduction of PDF uncertainties based on the Hessian method. Another important addition is the inclusion of pion production data from RHIC giving us a handle
to constrain gluon PDF.
In this presentation we briefly discuss the framework...
Mr
Ilkka Helenius
(Lund University)
28/04/2015, 14:25
WG1 Structure Functions and Parton Densities
The current nuclear PDF analyses are mainly constrained by fixed-target
DY and DIS data which provide direct constraints primarily for quarks at
$x > 0.001$. Some constraints for gluons are provided by the inclusive
pion production data in d+Au collisions at RHIC but due to the limited
kinematic reach of the data the small-$x$ nuclear gluon PDFs remain
practically unconstrained in the...
Roberto Petti
(University of South Carolina (US)), Dr
Sergey Kulagin
(INR)
28/04/2015, 14:50
WG1 Structure Functions and Parton Densities
We study the nuclear parton distribution functions [1] on the basis of our recently developed semi-microscopic model [2], which takes into account a number of nuclear effects including nuclear shadowing, Fermi motion and nuclear binding, nuclear meson-exchange currents and off-shell corrections to bound nucleon distributions.
We discuss in details the dependencies of nuclear effects on the...
Antonia Di Crescenzo
28/04/2015, 15:15
WG1 Structure Functions and Parton Densities
SHIP is a new general purpose fixed target facility, proposed at the CERN SPS accelerator.
In its initial phase the 400GeV proton beam will be dumped on a heavy target with the aim of integrating $2\times 10^{20}$ pot in 5 years.
A dedicated detector downstream the target will allow to probe a variety of models with light long-lived exotic particles and masses below O(10)...
Joel Mousseau
28/04/2015, 16:15
WG1 Structure Functions and Parton Densities
Neutrinos provide a unique probe of nuclear structure as they interact weakly and couple with partons via the axial as well as the vector current. The MINERvA experiment takes advantage of the Fermilab NuMI beam line and multiple nuclear targets to study neutrino + nucleus interactions. This talk presents preliminary results of MINERvAโs DIS sample in the neutrino energy ($E_{\nu}$) range of 5...
Dr
Xinchun Tian
(Univ. of South Carolina)
28/04/2015, 16:40
WG1 Structure Functions and Parton Densities
Resonance interaction is one of the most important neutrino interaction modes for neutrino oscillation experiments in the few-GeV energy region. This talk presents the analysis of resonance production in neutrino charged current interaction. The study is extended to the NOMAD data allowing the most precise neutrino resonance measurement to date. Some of the current discrepancies in the...
Vittorio Paolone
(University of Pittsburgh)
28/04/2015, 17:05
WG1 Structure Functions and Parton Densities
The high resolution near detector for the LBNE/F experiment, in conjunction with the high intensity and broad
energy range of the LBNE/F beam, will allow to collect about 10^8 inclusive neutrino charged current (CC)
interactions with a bubble-chamber quality reconstruction. Precision measurements of cross-sections
for several exclusive processes and of structure functions (F_T, F_2, F_3, R)...
Cedric Mezrag
29/04/2015, 08:30
WG1 Structure Functions and Parton Densities
We compute the pion quark Generalized Parton Distribution H and quark Double Distributions in a coupled Bethe-Salpeter and Dyson-Schwinger approach in terms of quarks flavors or isospin states. We use simple analytic expressions inspired by the numerical resolution of Dyson-Schwinger and Bethe-Salpeter equations. We obtain an analytic expression for the pion Generalized Parton Distribution at...
Dr
Marie Boรซr
(Institut de Physique Nuclรฉaire d'Orsay)
29/04/2015, 08:55
WG1 Structure Functions and Parton Densities
Hard exclusive processes on the nucleon have been the subject of intense studies for the past 15 years. In the regime where the scattering amplitude is factorized into a hard and a soft part, such reactions provide access to Generalized Parton Distributions (GPDs). These quantities contain informations about the longitudinal momentum and the transverse spatial distributions of quarks and...
Prof.
Arie Bodek
(University of Rochester (US))
29/04/2015, 09:45
WG1 Structure Functions and Parton Densities
We present results from a high precision experimental study of the nuclear modification of the longitudinal ($\sigma_L$) and transverse ($\sigma_T$) structure functions of nucleons bound in nuclear targets. The origin of these modifications (commonly referred as as the EMC effect) is not fully understood. Our measurements of R= $\sigma_L / \sigma_T$ for nuclei ($R_A$) and for...
Dr
Gabriel Niculescu
(James Madison University)
29/04/2015, 10:45
WG1 Structure Functions and Parton Densities
The Jefferson Lab. experiment BONuS used a novel spectator-tagging technique to measure the inclusive electron-free neutron scattering cross section and extract the F2 structure function. This data was used to reconstruct moments of F2 in the three prominent resonance region, as well as the moments integrated over the entire resonance region.
Comparisons of the experimental results with...
Nadia Fomin
(University of Tennessee)
29/04/2015, 11:10
WG1 Structure Functions and Parton Densities
Since the discovery of the EMC effect over 30 years ago, itโs been of great theoretical interest and studied in several experimental measurements. No unified picture arose to explain the underlying cause of per nucleon structure function modification in nuclei. Precise measurements on light nuclei from JLabโs 6 GeV era revitalized this research by showing that traditional A or density...
Dr
Matthew Posik
(Temple University)
29/04/2015, 11:35
WG1 Structure Functions and Parton Densities
Over the past several years the STAR experiment at RHIC has been contributing to our understanding of the proton structure. Through proton-proton collisions, STAR is well equipped to measure the e$^{\pm}$ leptonic decays of $W^{\pm}$ bosons in the mid-rapidity region (-1.1 $\le \eta \le $ 1.1) at $\sqrt{s}$ = 500/510 GeV. The $W$ cross section ratio ($W^+/W^-$) is sensitive to unpolarized $u$,...
Prof.
Pavel Nadolsky
(Southern Methodist University)
29/04/2015, 12:00
WG1 Structure Functions and Parton Densities
I review two methods for combination of PDF+QCD coupling uncertainties for LHC observables, based on meta-parametrizations of PDFs and compressed Monte Carlo replicas. The methods estimate combined PDF uncertainties using input PDF ensembles from several groups. They offer alternatives to the current PDF4LHC prescription for the combination of PDF uncertainties, and combine the PDFs at the...
Prof.
Simonetta Liuti
(University of Virginia)
29/04/2015, 14:00
WG1 Structure Functions and Parton Densities
I will discuss the application of an alternative type of neural network, the Self-Organizing Maps (SOMs), to extract parton distribution functions from various hard scattering processes. SOMs provide a complementary algorithm to NNPDFs yielding a parametrization that is free from the bias implicit in choosing specific analytic forms. At the same time it enables us to extrapolate to...
Kun Liu
(urn:Google)
29/04/2015, 14:25
WG1 Structure Functions and Parton Densities
Fermilab E906/SeaQuest is a fixed-target dimuon experiment using the 120 GeV proton beam from the Fermilab Main Injector. We have completed the first physics run in 2014 and continue collecting high statistic data samples of p+p, p+d, p+C, p+Fe and p+W collisions. E906 measures J/Psi, Psiโ and Drell-Yan yeilds in the dimuon channel over a wide range of kinematic coverages, which is optimal for...
Prof.
Arie Bodek
(University of Rochester (US))
29/04/2015, 14:50
WG1 Structure Functions and Parton Densities
We show that measurements of the forward-backward charge asymmetry ($A_{FB}(M)$) of Drell-Yan dilepton events produced at hadron colliders can be used to constrain Parton Distribution Functions (PDFs). PDF uncertainties are the dominant systematic error in the extraction of of electroweak parameters from hadron collider data. These parameters include the electroweak mixing angles...
Prof.
Alan Martin
(IPPP Durham),
Lucian Harland-Lang
(University College London), Mr
Patrick Motylinski
(UCL London), Prof.
Robert Samuel Thorne
(University College London (UK))
29/04/2015, 15:15
WG1 Structure Functions and Parton Densities
We present the MMHT2014 PDFs, an update of the previous major release in the
same framework, i.e. MSTW2008. We discuss the changes in both the central values
and uncertainties in the PDFs due to changes in theoretical procedures and the impact of new, largely LHC data-sets. We note, however, that changes in predictions are
rather small. We discuss the correlation between the PDFs and the...
Martin Hentschinski
(Institute for Nuclear Science, UNAM)
29/04/2015, 16:15
WG1 Structure Functions and Parton Densities
We revive the idea of using physical anomalous dimensions in the QCD scale evolution of deep-inelastic structure functions and their scaling violations and present a detailed phenomenological study of its applicability up to NNLO. In particular we are interested in the use of physical DGLAP evolution as a tool to detect possible deviations from linear DGLAP evolution at small x which signal...
Zachary Snyder
(Penn State)
29/04/2015, 16:40
WG1 Structure Functions and Parton Densities
We demonstrate the mathematical formalism for the construction of the consistent initial
conditions for the double parton distribution functions in the collinear approximation.
The initial conditions within this framework have an important property that they satisfy exactly simultaneously both the momentum sum rules and the quark sum rules and are at the same time related to the single...
Harleen Dahiya
(Dr. B.R. Ambedkar National Institute of Technology)
29/04/2015, 17:05
WG1 Structure Functions and Parton Densities
Electromagnetic form factors obtained from the overlap of light front wave functions (LFWFs) have been used to study the transverse densities of charge and magnetization. The calculations have been carried out to develop a relation between the charge distribution of the quarks inside nucleon in the transverse coordinate space as well as in the impact parameter space. The anomalous...
David Clark
(Southern Methodist University)
30/04/2015, 10:45
nobuo sato
(jlab)
30/04/2015, 11:10
Tomas Kasemets
(Nikhef/VU)
30/04/2015, 11:35
