Elementary Particles and Fields and String Theory Commons^™

Open Heavy Flavor Measurement At Forward Angles For Cu+Cu Collisions At Center Of Mass Nn Collision Energy 200 Gev, Irakli Garishvili

Doctoral Dissertations

The main purpose of Relativistic Heavy Ion Collider (RHIC) program is to study the Quark-Gluon Plasma (QGP), a deconfined state of matter believed to be created in ultra-relativistic heavy ion collisions. Heavy quarks, expected to be produced during the earlier stages of heavy ion collisions, serve as an important probe of the QGP.‎

‎The following dissertation presents measurements of single muons resulting from the semileptonic decay of heavy flavor quarks in the rapidity range of $1.4 < \vert\eta\vert < 1.9$ for Cu+Cu nuclei collisions at $\sqrt{s_{NN}}=200$ GeV measured by the PHENIX experiment. Single muon spectra were measured for three different centrality classes (0 - 20 \% , 20 - 40 \%, 40 - 94 \%) within the $p_{T}$ range of 1.0 - 4.0 GeV/c.‎

‎To calculate single muon spectra, a full background estimate was statistically subtracted from inclusive spectra of muon candidate tracks reconstructed in the PHENIX muon …

Polarimetry Studies For The Npdgamma Experiment At The Sns, Jonny Dadras

Jonny Dadras

The NPDGamma collaboration aims to measure a parity-violating directional gamma-ray asymmetry from the capture of polarized cold neutrons on protons. The asymmetry, predicted to be on the order of 50 ppb, is a result of the weak interaction between mesons and nucleons during the neutron capture reaction. The experiment is designed to make a statistics limited measurement of the asymmetry at the level of about 20%. The experiment will be carried out at the Fundamental neutron Physics Beamline (FnPB) at the Spallation Neutron Source (SNS). The neutron beam is polarized by a super-mirror polarizer. A 9.5 G magnetic field guides …

Contributing Efforts In The Search For Neutrinoless Double Beta Decay, Laura Christine Sparks

Physics

Cryogenic Underground Observatory for Rare Events (CUORE) will be part of the next generation of detectors used to search for neutrinoless double beta decay (0νββ). Located in Assergi, Italy at the Gran Sasso National Laboratory (LNGS), CUORE will be a large cryogenic bolometer composed of 988 tellurium dioxide (TeO2) detectors with a total mass of 750 kg, and will search for 0νββ in 130Te. As the experiment will monitor the extremely rare event of 0νββ, all factors contributing to background need to be minimized to effectively increase the sensitivity. I assisted the LNGS researchers over the summer of 2008 by …

Heavy-Flavor Production At Accelerators, Nikolaos Kidonakis

Faculty and Research Publications

I discuss heavy flavor production at hadronic facilities. I present total cross sections and differential distributions for top quark, bottom quark, and charm quark production at the rrevatron and LHC colliders, and at fixed-target experiments such as HERA-B. The calculations include complete next-to-leading order corrections as well as higher-order soft-gluon corrections which are important near kinematical threshold.

Time-Delay And Doppler Tests Of The Lorentz Symmetry Of Gravity, Quentin G. Bailey

Physics & Astronomy - Prescott

Modifications to the classic time-delay effect and Doppler shift in general relativity (GR) are studied in the context of the Lorentz-violating standard-model extension (SME). We derive the leading Lorentz- violating corrections to the time-delay and Doppler shift signals, for a light ray passing near a massive body. It is demonstrated that anisotropic coefficients for Lorentz violation control a time-dependent behavior of these signals that is qualitatively different from the conventional case in GR. Estimates of sensitivities to gravity-sector coefficients in the SME are given for current and future experiments, including the recent Cassini solar conjunction experiment.

Catching Relativity Violations With Atoms, Quentin G. Bailey

Physics & Astronomy - Prescott

A Viewpoint on: Atom interferometry tests of local Lorentz invariance in gravity and electrodynamics Keng-Yeow Chung, Sheng-wey Chiow, Sven Herrmann, Steven Chu and Holger Müller Phys. Rev. D 80, 016002 (2009) – Published July 6, 2009.

High Energy Particle Physics At The University Of Tennessee, Stefan M Spanier

Physics and Astronomy Publications and Other Works

Talk given at the Governor's school in 2009. It is an introduction to particle physics.

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 …

A Trip To The Beginning Of The Universe With The Large Hadron Collider, Stefan M Spanier

Physics and Astronomy Publications and Other Works

Slides from a presentation given at the Science Forum of the University of Tennessee. It discusses the physics program of the Large Hadron Collider in general terms. Serves as introductory material to the field.

Class Of Nonperturbative Configurations In Abelian-Higgs Models: Complexity From Dynamical Symmetry Breaking, M. Gleiser, J. Thorarinson

Dartmouth Scholarship

We present a numerical investigation of the dynamics of symmetry breaking in both Abelian and non-Abelian [SU(2)] Higgs models in three spatial dimensions. We find a class of time-dependent, long-lived nonperturbative field configurations within the range of parameters corresponding to type-1 superconductors, that is, with vector masses (mv) larger than scalar masses (ms). We argue that these emergent nontopological configurations are related to oscillons found previously in other contexts. For the Abelian-Higgs model, our lattice implementation allows us to map the range of parameter space—the values of β=(ms/mv)2—where such configurations exist and to follow them for times t∼O(105)m−1. An investigation …

Five-Dimensional 2-Branes And The Universal Hypermultiplet, Moataz Emam

Moataz Emam

No abstract provided.

Symplectic Covariance Of The N = 2 Hypermultiplets, Moataz Emam

Moataz Emam

No abstract provided.

Performance Of A Single-Crystal Diamond-Pixel Telescope, R. Hall-Wilton, V. Ryjov, M. Pernicka, V. Halyo, B. Harrop, A. Hunt, D. Marlow, E. Bartz, J. Doroshenko, D. Hits, S. Schnetzer, R. Stone, W. Bugg, M. Hollingsworth, Stefan Spanier, W. Johns

stefan spanier

We describe the results from a beam test of a telescope consisting of three planes of single-crystal, diamond pixel detectors. This telescope is a prototype for a proposed small-angle luminosity monitor, the Pixel Luminosity Telescope (PLT), for CMS. We recorded the pixel addresses and pulse heights of all pixels over threshold as well as the fast-or signals from all three telescope planes. We present results on the telescope performance including occupancies, pulse heights, fast-or efficiencies and particle tracking. These results show that the PLT design concept is sound and indicate that the project is ready to proceed with the next …

Measurement Of The Differential Cross Section For The Reaction Γn →Π⁻P From Deuterium, M. J. Amaryan, H. Badasaryan, S. L. Careccia, G. E. Dodge, C. E. Hyde, S. E. Kuhn, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., The Clas Collaboration

Physics Faculty Publications

We report a measurement of the differential cross section for the γn →π⁻p process from the CLAS detector at Jefferson Laboratory in Hall B for photon energies between 1.0 and 3.5 GeV and pion center-of-mass (c.m.) angles (𝜃 _c.m.) between 50° and 115°. We confirm a previous indication of a broad enhancement around a c.m. energy (√ s) of 2.1 GeV at 𝜃_c.m. = 90° in the scaled differential cross section s^{7 dσ}_dt and a rapid falloff in a center-of-mass energy region of about 400 MeV following the enhancement. Our data show an angular dependence of …

Measurement Of Direct Fₒ(980) Photoproduction On The Proton, K. P. Adhikari, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, N. Kalantarians, A. Klein, A.V. Klimenko, S. E. Kuhn, J. Lanchiet, M. R. Niroula, J. Zhang

Physics Faculty Publications

We report on the results of the first measurement of exclusive f₀(980) meson photoproduction on protons for E_γ = 3.0–3.8  GeV and −t = 0.4–1.0  GeV² . Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the π⁺π⁻ channel by performing a partial wave analysis of the reaction γp→pπ⁺π⁻ . Clear evidence of the f₀(980) meson was found in the interference between P and S waves at M _π+π− ∼1  GeV. The S -wave differential …

Moments Of The Spin Structure Functions G(1)(P) And G(1)(D) For 0.05 < Q2 < 3.0 Gev2, Clas Collaboration, Y. Prok, K. V. Dharmawardane, G. E. Dodge, S. E. Kuhn, M. J. Amaryan, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. Gavalian, N. Guler, C. E. Hyde-Wright, H. G. Juengst, N. Kalantarians, A. Klein, J. Lachniet, R. A. Niyazov, L. M. Qin, S. Sabatie, S. Tkachenko, L. B. Weinstein, J. Zhang

Physics Faculty Publications

The spin structure functions g1 for the proton and the deuteron have been measured over a wide kinematic range in x and Q² using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH3 and ND3 targets at Jefferson Lab. Scattered electrons were detected in the CEBAF Large Acceptance Spectrometer, for 0.05 < Q² < 5GeV² and W < 3 GeV. The first moments of g1 for the proton and deuteron are presented – both have a negative slope at low Q², as predicted by the extended Gerasimov–Drell–Hearn sum rule. The first extraction of the generalized forward spin polarizability of the proton γ p 0 the Q² evolution of the first moment of g1 shows agreement in leading order with Heavy …

Search For The Photoexcitation Of Exotic Mesons In The Π+Π+Π- System, Clas Collaboration, M. J. Amaryan, H. Bagdasaryan, S. Bektasoglu, S. Bültmann, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, J. Lachniet, M. R. Niroula, L. M. Qin, S. Tkachenko, L. B. Weinstein, J. Zhang

Physics Faculty Publications

A search for exotic mesons in the π⁺π⁺π⁻ system photoproduced by the charge exchange reaction γp→π⁺π⁺π⁻(n) was carried out by the CLAS Collaboration at Jefferson Lab. A tagged-photon beam with energies in the 4.8 to 5.4 GeV range, produced through bremsstrahlung from a 5.744 GeV electron beam, was incident on a liquid-hydrogen target. A partial wave analysis was performed on a sample of 83 000 events, the highest such statistics to date in this reaction at these energies. The main objective of this study was to look for the …

Energy And System Size Dependence Of Φ Meson Production In Cu + Cu And Au + Au Collisions, B. I. Abelev, M. M. Aggarwal, Z. Ahammed, B. D. Anderson, D. Arkhipkin, G. S. Averichev, Y. Bai, J. Balewski, O. Barannikova, L. S. Barnby, S. Bültmann

Physics Faculty Publications

We study the beam-energy and system-size dependence of ϕ meson production (using the hadronic decay mode ϕ → K ⁺ K ⁻ ) by comparing the new results from Cu + Cu collisions and previously reported Au + Au collisions at √^sNN = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented in this Letter are from mid-rapidity ( | y | < 0.5 ) for 0.4 < PT < 5 GeV /c . At a given beam energy, the transverse momentum distributions for ϕ mesons are observed to be similar in yield and shape for Cu + Cu and Au + …

Nlo Evolution Of Color Dipoles In N=4sym, Ian Balitsky, Giovanni A. Chrilli

Physics Faculty Publications

High-energy behavior of amplitudes in a gauge theory can be reformulated in terms of the evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the conformally invariant BK equation for the evolution of color dipoles. In QCD, the next-to-leading order BK equation has both conformal and non-conformal parts, the latter providing the running of the coupling constant. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformal N = 4 SYM theory. We define the "composite dipole operators" with the rapidity cutoff preserving conformal …

New Compact Tem-Type Deflecting And Crabbing Rf Structure, J. R. Delayen, H. Wang

Physics Faculty Publications

A new type of rf structure for the deflection and crabbing of particle beams is presented. The structure is comprised of a number of parallel TEM resonant lines operating in opposing phase from each other. One of its advantages is its compactness compared to conventional crabbing cavities operating in the TM₁₁₀ mode, thus allowing low frequency designs. This geometry would also be effective for the deflection of beams propagating at velocities substantially less than that of light.

Measurement Of Semi-Inclusive Π+ Electroproduction Off The Proton, Clas Collaboration, M. J. Amaryan, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, M. R. Niroula, L. M. Qin, L. B. Weinstein, J. Zhang

Physics Faculty Publications

Semi-inclusive π+ electroproduction on protons has been measured with the CLAS detector at Jefferson Lab. The measurement was performed on a liquid-hydrogen target using a 5.75 GeV electron beam. The complete five-fold differential cross sections were measured over a wide kinematic range including the complete range of azimuthal angles between hadronic and leptonic planes, ϕ , enabling us to separate the ϕ-dependent terms. Our measurements of the ϕ -independent term of the cross section at low Bjorken x were found to be in fairly good agreement with pQCD calculations. Indeed, the conventional current fragmentation calculation can account for almost all …

Photodisintegration Of 4He Into P+T, Clas Collaboration, M. J. Amaryan, S. L. Careccia, G. E. Dodge, C. E. Hyde, S. E. Kuhn, M. Mayer, C. S. Nepali, M. R. Niroula, H. Seraydaryan, S. Tkachenko, L.B. Weinstein, J. Zhang

Physics Faculty Publications

The two-body photodisintegration of 4He into a proton and a triton has been studied using the CEBAF Large-Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. Real photons produced with the Hall-B bremsstrahlung-tagging system in the energy range from 0.35 to 1.55 GeV were incident on a liquid ⁴He target. This is the first measurement of the photodisintegration of ⁴He above 0.4 GeV. The differential cross sections for the γ ⁴He →pt reaction were measured as a function of photon-beam energy and proton-scattering angle and are compared with the latest model calculations by J.-M. Laget. At …

Electroexcitation Of Nucleon Resonances From Clas Data On Single Pion Electroproduction, Clas Collaboration, K. P. Adhikari, S. L. Careccia, T. A. Forest, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, C. S. Nepali, M. R. Niroula, H. Seraydaryan

Physics Faculty Publications

We present results on the electroexcitation of the low mass resonances Δ(1232)P₃₃ , N(1440)P₁₁ , N(1520)D₁₃ , and N(1535)S₁₁ in a wide range of Q². The results were obtained in the comprehensive analysis of data from the Continuous Electron Beam Accelerator Facility (CEBAF) large acceptance spectrometer (CLAS) detector at the Thomas Jefferson National Accelerator Facility (JLab) on differential cross sections, longitudinally polarized beam asymmetries, and longitudinal target and beam-target asymmetries for π electroproduction off the proton. The data were analyzed using two conceptually different approaches—fixed-t dispersion relations and a unitary isobar model—allowing us to …

Conformal Kernel For The Next-To-Leading-Order Bfkl Equation In 𝒩 = 4 Super Yang-Mills Theory, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

Using the requirement of Möbius invariance of 𝒩 = 4 super Yang-Mills amplitudes in the Regge limit, we restore the explicit form of the conformal next-to-leading-order Balitsky-Fadin-Kuraev-Lipatov (BFKL) kernel out of the eigenvalues known from the forward next-to-leading-order BFKL result.

Spin Structure Of The Deuteron, Nevzat Guler

Physics Theses & Dissertations

Double spin asymmetries for the proton and the deuteron have been measured in the EG1b experiment using the CLAS detector at Jefferson Lab. Longitudinally polarized electrons at energies 1.6, 2.5, 4.2 and 5.7 GeV were scattered from longitudinally polarized NH3 and ND3 targets. The double spin asymmetry A|| for the proton and the deuteron has been extracted from these data as a function of W and Q² with unprecedented precision. The virtual photon asymmetry A₁ and the spin structure function g1 can be calculated from these measurements by using parametrization to the world data for the virtual …