Ashish Kumar
(SUNY Buffalo)
15/08/2013, 13:50
QCD Physics
oral presentation
Studies of associated production of a W, Z or photon with jets provide important tests of perturbative quantum chromodynamics calculations. A good understanding of such processes is essential in part because they constitute a major background to the production of the standard model Higgs boson in association with a vector boson. Recent measurements of the production of a vector boson plus...
Peter Onyisi
(U. Texas Austin)
15/08/2013, 14:10
QCD Physics
oral presentation
Compared to inclusive J/psi production, the associated production of weak vector bosons and J/psi mesons in hadron collisions selects a different set of partonic initial states and provides complementary information on quarkonium production mechanisms. Using 4.6 inverse femtobarns of pp collisions at sqrt(s) = 7 TeV recorded by ATLAS, we observe and measure the rate of W+J/psi associated...
Mr
Rajivalochan Subramaniam
(Louisiana Tech University)
15/08/2013, 14:30
QCD Physics
oral presentation
A measurement of angular correlations of jets in hadron collisions is presented. This measurement is sensitive to QCD dynamics and to the strong coupling constant, while being only weakly sensitive to parton distribution functions. The observable is the number of neighboring jets above a given transverse momentum threshold which accompany a given jet within a distance $\Delta R$ in the plane...
Prof.
chunhui chen
(Iowa State University)
15/08/2013, 14:50
QCD Physics
oral presentation
We introduce a new approach to study jet substructure in the center-of-mass frame of the jet. We demonstrate that it can be used to discriminate the boosted heavy particles from the QCD jets and the method is complimentary to the existing other jet substructure algorithms. Applications to searches for hadronically decaying W/Z+jets, top jet and heavy resonance that decays to final states with...
Dr
Ray Culbertson
(FNAL)
15/08/2013, 16:00
QCD Physics
oral presentation
The CDF Collaboration continues to analyze the complete, legacy
dataset of approximately 10 fb-1. This report will cover
several recent analyses which feature high-energy photons.
QCD hard interactions and proton structure can be probed by
comparing measurements of photon cross sections to state-of-the-art
calculations. We will report cross section measurements for events
with...
Nobuo Sato
(Florida State University)
15/08/2013, 16:20
QCD Physics
oral presentation
The precise knowledge of parton distribution functions at large-x is important in order to understand the production of a massive state at forward rapidities at the LHC. Currently, the gluon PDF is highly unconstrained at large-x and it is mainly constrained by jet data. In the past, direct photon production with high transverse momentum at fixed target experiments was used to constrain gluon...
Mr
David Westmark
(Florida State University)
15/08/2013, 16:40
QCD Physics
oral presentation
The precise knowledge of parton distribution functions (PDFs) is indispensable to the accurate calculation of hadron-initiated QCD hard scattering observables. Much of our information on PDFs is extracted by comparing deep inelastic scattering (DIS) and lepton pair production (LPP) data to convolutions of the PDFs with the partonic cross sections of these processes. It is known that partonic...
Radja Boughezal
(Argonne)
16/08/2013, 08:30
QCD Physics
oral presentation
Review of recent higher-order QCD calculations.
Dr
Pavel Nadolsky
(Southern Methodist University)
16/08/2013, 09:10
QCD Physics
oral presentation
Review of recent progress on PDFs.
Dr
Simone Alioli
(Lawrence Berkeley National Laboratory)
16/08/2013, 09:40
QCD Physics
oral presentation
Review of recent progress in matching higher order calculations and parton showers.
Dr
Christopher Kelly
(Columbia University)
16/08/2013, 10:40
QCD Physics
oral presentation
Direct CP-violation was first observed in the late 1990s in K->pi pi decays, and precise experimental measurements have since been made. However until recently it has not been possible to calculate its measure directly from the Standard Model due to it receiving large contributions from QCD in the hadronic regime in which perturbation theory is not applicable. This is unfortunate because these...
Dr
Ye Li
(SLAC)
16/08/2013, 11:00
QCD Physics
oral presentation
We study the change in the di-photon invariant mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for gluon pair to photon pair. Previously, the apparent Higgs mass was found to shift by around 100 MeV in the Standard Model in the leading order approximation, which may potentially be...
Ms
Sonam Mahajan
(Panjab University, Chandigarh, India)
16/08/2013, 11:20
QCD Physics
oral presentation
The Main Injector Particle Production (MIPP) experiment at Fermilab is a fixed target hadron production experiment. It measures particle production in interactions of 120 GeV/c primary protons from the Main Injector and secondary beams of $\pi^{\pm}, \rm{K}^{\pm}$, p and $\bar{\rm{p}}$ from 5 to 90 GeV/c on nuclear targets which include H, Be, C, Bi and U, and a dedicated run with the NuMI...
David Muller
(SLAC)
16/08/2013, 11:40
QCD Physics
oral presentation
Inclusive hadron production cross sections in
e+e- collisions shed light on fundamental questions of hadronization and
fragmentation processes. We present measurements of inclusive spectra
of various light hadrons produced in e+e- collisions at a center-of-mass energy
of about 10.5 GeV. These results help test the scaling properties of the cross
sections by comparison with previous...
David Brown
(University of Louisville)
16/08/2013, 14:30
QCD Physics
oral presentation
Baryonic decays account for about 7% of the B-meson width, and have been studied
in recent years by the B factories.
These studies reveal properties of hadronization at low q^2, such as s anti-s suppression
known from jet fragmentation, and phase space relations between the baryon and antibaryon.
The measurement and comparison of exclusive branching fractions of
baryonic B decays...
Mr
Prabhakar Palni
(on behalf of the CDF collaboration)
16/08/2013, 14:50
QCD Physics
oral presentation
Using data from proton-antiproton collisions at center of mass energy of 1.96 TeV recorded by the CDF II detector at the Fermilab Tevatron, evidence for the excited resonance state Lambda_b* is presented in its fully reconstructed decay mode to Lambda_b0 pi+ pi- where Lambda_b0 decays to Lambda_c+ pi- with Lambda_c+ decays to p K- pi+. The analysis is based on a data sample corresponding to an...
Concetta Cartaro
(SLAC)
16/08/2013, 15:10
QCD Physics
oral presentation
We present a study of the e+e- --> p anti-p process
using initial state radiation with BABAR. The BABAR data sample,
469 fb-1, collected at and near Y(4S) has been used to measure
the e+e- --> p anti-p cross section and the proton effective
electromagnetic form factor. The ratio of the electric and
magnetic form factors has been extracted from an analysis of the proton
angular...
Dr
Emanuele Santovetti
(INFN - Roma Tor Vergata)
16/08/2013, 15:30
QCD Physics
oral presentation
Studies of quarkonia production in the forward region provide important tests of NRQCD. The LHCb experiment has collected a dataset corresponding to an integrated luminosity of about 3 fb-l in proton-proton collisions at sqrt(s)= 7 and 8 TeV. We present studies of the production and polarisation of the J/psi, psi(2S) and chi_c charmonium states as well as those of Upsilon and chi_b bottomonia....
Dr
Wei Chen
(University of Saskatchewan)
16/08/2013, 16:10
QCD Physics
oral presentation
We have calculated the correlation functions of heavy quarkonium hybrid operators with various $J^{PC}$ quantum numbers to include QCD condensates up to dimension six.
As observed before, the dimension six condensates could stabilize the hybrid sum rules
and permit reliable mass predictions. After performing the QCD sum rule analysis, we
extract the masses of charmonium and bottomonium...
Eric Braaten
(Ohio State University)
16/08/2013, 16:30
QCD Physics
oral presentation
Flavor-exotic tetraquark mesons have recently been observed in the heavy-quark pair sectors of QCD, including two isospin multiplets in the b b-bar sector, Z_b(10610) and Z_b(10650), and one isospin multiplet in the c c-bar sector, Z_c(3900). We identify Z_b and Z_c as tetraquark mesons that are analogs of quarkonium hybrids with the gluon field replaced by an isospin-1 excitation of the...
Mr
Ryan Berg
(University of Saskatchewan)
16/08/2013, 16:50
QCD Physics
oral presentation
We use QCD Laplace sum-rules to predict ground state masses for $J^{PC}=0^{+-}$ and $J^{PC}=1^{--}$ strangeonium hybrids. In our calculations, we include contributions stemming from perturbation theory, 4d quark and gluon condensates, the 5d mixed condensate, and 6d quark and gluon condensates. These two $J^{PC}$-channels are of particular phenomenological interest as the Y(2175) has quantum...
