244 Works

DIS with Neutrinos: Now and When.

Jorge G. Morfin
the NuTeV $\nu$-Fe experiment that used the high-energy TeVatron neutrino beam. The problem the community faces in trying to study QCD with modern neutrino data is that there is no experimentally verified way to scale neutrino-nucleus (for example, Fe) results to the equivalent neutrino-nucleon values and there are now indications that nuclear effects in neutrino nucleus interactions might be different than those measured in charged-lepton nucleus scattering. To better understand this situation, the \minerva\ neutrino-nucleus...

The NLO jet vertex for Mueller-Navelet and forward jets in the small-cone approximation.

Dmitry Yu. Ivanov & Alessandro Papa
We calculate in the next-to-leading order the impact factor (vertex) for the production of a forward high-$p_T$ jet, in the approximation of small aperture of the jet cone in the pseudorapidity-azimuthal angle plane. The final expression for the vertex turns out to be simple and easy to implement in numerical calculations.

Inclusive low mass Drell-Yan production in the forward region at $\sqrt{s}$ = 7 TeV.

Jonathon Anderson
A measurement of the Drell-Yan cross-section in dimuon final states for muons within pseudorapidities of 2 to 4.5, in the mass range 5 $ < $ M $ < $ 120 GeV/c$^{2}$, is presented. The muons are required to have a momenta larger than 10 GeV/c and a transverse momenta larger that 3 GeV/c. The cross section is measured differentially, in mass, and in rapidity of the virtual photon in two distinct mass regions. The...

Precision QCD Measurements at HERA.

Karin Daum
Recent QCD results obtained by the H1 and ZEUS collaborations at the $ep$ collider HERA are presented. The high precision measurements of the inclusive deep-inelastic scattering cross section at high photon virtualities $Q^2$ are used to search for signs of physics beyond the Standard Model. The studies of hadronic final states such as diffraction, jet and heavy quark production as well as particle production are summarised. Predictions from perturbative QCD are confronted with these measurements...

An AdS/QCD holographic wavefunction for the $\rho$ meson.

Jeff Forshaw & Ruben Sandapen
We use an AdS/QCD holographic wavefunction to generate predictions for the rate of diffractive $\rho$-meson electroproduction that are in reasonable agreement with data collected at the HERA electron-proton collider.

The STAR Experiment: The second decade and beyond.

Matthew A. C. Lamont
The STAR experiment at RHIC has been running successfully for over 10 years. Over this time, many upgrades have been made to the detector configuration, driven by the physics requirements. In this presentation, I will review the upgrades in the near term with respect to A+A and $p$+$p$ physics and review what STAR can contribute to an eRHIC era.

Helicity Parton Distributions at an EIC.

Elke C. Aschenauer, Rodolfo Sassot & Marco Stratmann
We present a quantitative assessment of the impact of a future EIC on determinations of helicity quark and gluon densities and their contributions to the proton spin. Our results are obtained by performing global QCD analyses at NLO accuracy based on realistic sets of pseudo-data for various conceivable center-of-mass system energies.

Multidimensional study of the hadron attenuation at HERMES.

Gevorg Karyan
Hadron multiplicity ratios in semi-inclusive deep-inelastic scattering have been measured on neon, krypton and xenon targets relative to deuterium using 27.6 GeV positron or electron beam at the HERMES experiment. They are presented for pions ($\pi^{+}$, $\pi^{-}$), kaons ($K^{+}$, $K^{-}$), protons and anti-protons as a function of the virtual photon energy $\nu$, its virtuality $Q^{2}$, the fractional hadron energy $z$ and the transverse component of hadron momentum $p_{t}$ with respect to the direction of the...

Fragmentation Functions at Belle.

Martin Leitgab
Fragmentation functions (FFs) describe the formation of final state particles from a partonic initial state. Precise knowledge of these functions is a key ingredient in accessing quantities such as the nucleon spin structure in semi-inclusive deep-inelastic scattering and proton proton collisions. However, fragmentation functions can currently not be determined from first principles Quantum Chromodynamics and have to be extracted from experimental data. The Belle experiment at KEK, Japan, provides a large data sample for high...

Transverse Momentum Dependent Parton Distributions at an Electron-Ion Collider.

Feng Yuan
We summarize the current status and future perspective of the transverse momentum dependent parton distributions at an electron-ion collider.

Search for New Physics with leptons and/or jets at ATLAS.

Antonio Policicchio
Data taken in 2011 with the ATLAS detector at the Large Hadron Collider (LHC) have been used to search for physics beyond the Standard Model. Results are presented based on between 1 and 5~fb$^{-1}$ of $\sqrt(s)$ = \unit{7}{\TeV} proton-proton collisions mainly focussing on final states with jets and/or leptons. No evidence of new physics is found.

Recent Results of Double Helicity Asymmetries from PHENIX.

Scott Wolin
The search for the gluon contribution to the proton spin, $\Delta G$, is critical to understanding the proton spin puzzle. The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) is able to directly probe gluon polarization using collisions between two polarized proton beams. $\Delta G$ is determined from the double longitudinal asymmetry, $A_{LL}$, for a final state to be observed between same and opposite sign helicity proton interactions. In this talk we will summarize...

Two-Loop Gluon Regge Trajectory from Lipatov's Effective Action

Grigorios Chachamis, Martin Hentschinski, Jose Daniel Madrigal & Agustin Sabio Vera
20th International Workshop on Deep-Inelastic Scattering and Related Subjects, DIS 2012, Bonn, Germany, 26 Mar 2012 - 30 Mar 2012; Hamburg : Deutsches Elektronen-Synchrotron, DESY 553-556 (2012). doi:10.3204/DESY-PROC-2012-02/129

Pion and Kaon Multiplicities from muon-deuteron Deep Inelastic Scattering at COMPASS.

Nour Makke
The hadronization process, which turns partons into non-perturbative hadronic bound states in hard-scattering reactions, plays a fundamental role in our understanding of the proton structure. Currently, our knowledge of quark Fragmentation Functions into hadrons (FFs) originates mainly from existing global QCD analyzes which are mostly based on inclusive measurements in electron-positron annihilation process. While the latter, with current available data, mainly fixes the flavor singlet combinations of FFs, semi-inclusive DIS measurements give access to the...

Phenomenology of Sivers Effect with TMD Evolution.

Mauro Anselmino, Mariaelena Boglione & Stefano Melis
Following the TMD evolution scheme recently proposed for the unpolarized and the Sivers distribution function, we propose a simple strategy to take into account this TMD $Q^2$ dependence in our phenomenological extraction of the Sivers function from SIDIS data. New results are presented and possible future applications are discussed.

Search for Heavy Stable Charged Particles with the CMS detector at the LHC.

Loic Quertenmont
Heavy Stable (or quasi-stable) Charged Particles (HSCP) are predicted by various extensions to the Standard Model of the fundamental interactions among elementary particles. If this prediction reveals to be true, such particles should be produced at the Large Hadron Collider (LHC) and observable with the Compact Muon Solenoid (CMS) detector. Results of the search for slowly moving (or stopped) HSCP with an integrated luminosity of 4.7~fb$^{-1}$ (0.9~fb$^{-1}$) is described.

Subleading-$N_c$ improved parton showers.

Simon Plaetzer & Malin Sjoedahl
We present an algorithm for improving subsequent parton shower emissions by full SU(3) colour correlations in the framework of a dipole-type shower. As a proof of concept, we present results from the first implementation of such an algorithm for a final state shower.

Searches for Fourth Generation Heavy Quarks with the ATLAS Detector.

Jiahang Zhong
The addition of one or more generations of heavy fermions is a natural extension to the Standard Model. Fourth generation heavy quarks can be produced at the LHC at rates that can be observed in the 2011 data samples, depending on the quark mass. The talk presents results from searches performed by the ATLAS collaboration for fourth generation quarks decaying via several potential decay channels.

Searches at ZEUS.

Stefano Antonelli
The results of recent searches for scalar and vector leptoquarks and anomalous single top production in $e^{\pm}$ collisions at HERA are presented. The searches make use of the full ZEUS data set corresponding to $0.5 \thickspace\invfemtobarn$. No evidence for leptoquarks signals is found and limits are set on the Yukawa coupling, $\lambda$, as a function of the leptoquark mass for different leptoquark types within the Buchm\"{u}ller-R\"{u}ckl-Wyler model. No evidence for top production is found and...

Search for the rare decays $B \rightarrow \mu^+\mu^-$ with the CMS detector.

Franco Simonetto
I summarize here the results of a search for the rare decays $B^0 \rightarrow \mu^+\mu^-$ and $B^0_s\rightarrow \mu^+\mu^-$, based on a sample of data collected by the CMS detector from $pp$ collisions at $\sqrt{s} =7$ \TeV, corresponding to an integrated luminosity of 4.9 \invfb . No excess of events over the expected background is observed. The resulting upper limits on the branching fractions are \mbox{${\cal B}(B_s^0 \rightarrow \mu^+ \mu^- ) < 7.7 \times 10^{-9}$} and...

Precision Measurements of the Proton Structure.

Iris Abt
The ``proton structure'' is a wide field. Discussed are predominantly the precision measurements of the proton structure functions at HERA and some of their implications for the LHC measurements. In addition, a discussion of what a proton structure function represents is provided. Finally, a connection to nuclear physics is attempted.

Using the BFKL Resummation to Fit DIS Data: Collinear and Running Coupling Effects

M. Hentschinski, A. Sabio Vera & C. Salas
20th International Workshop on Deep-Inelastic Scattering and Related Subjects, DIS 2012, Bonn, Germany, 26 Mar 2012 - 30 Mar 2012; Hamburg : Deutsches Elektronen-Synchrotron, DESY 429-432 (2012). doi:10.3204/DESY-PROC-2012-02/97

Searches for the standard model scalar boson in CMS and for new physics in ATLAS and CMS.

Barbara Clerbaux
Latest LHC results are reported focussing on the search for the standard model scalar boson, as well as a selection of searches for new physics beyond the standard model.

The ATLAS Upgrade programme.

Claudia Gemme
After the first successful years of LHC running, plans are actively advancing for a series of upgrades leading eventually to about five times the design-luminosity some 10-years from now. uCoping with the high instantaneous and integrated luminosity will be a great challenge for the ATLAS detector and will require changes in most of the subsystems, specially those at low radii and large pseudorapidity, as well as in its trigger architecture. Plans to consolidate and improve...

Top Quark Pair Production beyond the Next-to-Leading Order.

Valentin Ahrens, Andrea Ferroglia, Matthias Neubert, Ben D. Pecjak & Li Lin Yang
We report on recent calculations of the total cross section and differential distributions of top quark pair production at hardon colliders, including the invariant mass distribution, the transverse momentum and rapidity distributions, as well as the forward-backward asymmetry. The calculations are based on soft gluon resummation at the next-to-next-to-leading logarithmic accuracy.

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