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in creator/contributor: "Lawrence Berkeley National Laboratory. Nuclear Science Division."  
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kt-factorization for Hard Processes in Nuclei

Description: Two widely proposed kt-dependent gluon distributions in the small-x saturation regime are investigated using two particle back-to-back correlations in high energy scattering processes. The Weizsacker-Williams gluon distribution, interpreted as the number density of gluon inside the nucleus, is studied in the quark-antiquark jet correlation in deep inelastic scattering. On the other hand, the unintegrated gluon distribution, defined as the Fourier transform of the color-dipole cross section, is … more
Date: September 13, 2010
Creator: Dominguez, Fabio; Xiao, Bo-Wen & Yuan, Feng
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Lifetime Measurement of the 2{sup +}{sub 1} state in {sup 20}C

Description: Establishing how and when large N/Z values require modified or new theoretical tools is a major quest in nuclear physics. Here we report the first measurement of the lifetime of the 2{sup +}{sub 1} state in the near-dripline nucleus {sup 20}C. The deduced value of {tau}{sub #28;2{sup +}{sub 1}} = 9.8 ± 2.8(stat){sup +0.5}{sub −1.1}(syst) ps gives a reduced transition probability of B(E2;2{sup +}{sub 1}{yields}0{sup +}{sub g.s.}) = 7.5{sup +3.0}{sub −1.7}(stat){sup +1.0}{sub −0.4}(syst) e{sup 2}… more
Date: June 28, 2011
Creator: Petri, Marina-Kalliopi; Fallon, Paul; Macchiavelli, Augusto; Paschalis, Stephanos; Starosta, Krzysztof; Baugher, Travis et al.
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Partner: UNT Libraries Government Documents Department
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Micrometeorite Impacts in Beringian Mammoth Tusks and a Bison Skull

Description: We have discovered what appear to be micrometeorites imbedded in seven late Pleistocene Alaskan mammoth tusks and a Siberian bison skull. The micrometeorites apparently shattered on impact leaving 2 to 5 mm hemispherical debris patterns surrounded by carbonized rings. Multiple impacts are observed on only one side of the tusks and skull consistent with the micrometeorites having come from a single direction. The impact sites are strongly magnetic indicating significant iron content. We analyzed… more
Date: February 3, 2010
Creator: Hagstrum, Jonathon T.; Firestone, Richard B; West, Allen; Stefanka, Zsolt & Revay, Zsolt
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Partner: UNT Libraries Government Documents Department
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A measurement of the 2 neutrino double beta decay rate of Te-130 in the CUORICINO experiment

Description: CUORICINO was a cryogenic bolometer experiment designed to search for neutrinoless double beta decay and other rare processes, including double beta decay with two neutrinos (2{nu}{beta}{beta}). The experiment was located at Laboratori Nazionali del Gran Sasso and ran for a period of about 5 years, from 2003 to 2008. The detector consisted of an array of 62 TeO{sub 2} crystals arranged in a tower and operated at a temperature of #24;10 mK. Events depositing energy in the detectors, such as radi… more
Date: November 3, 2011
Creator: Kogler, Laura
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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A simple, high-yield, apparatus for NEG coating of vacuum beamline elements

Description: Non-Evaporable Getter (NEG) materials are extremely useful in vacuum systems for achieving Ultra High Vacuum. Recently, these materials have been used to coat the inner surfaces of vacuum components, acting as an internal, passive, vacuum pump. We have constructed a low cost apparatus, which allows coating of very small diameter vacuum tubes, used as differential pumping stages. Despite the relative ease of construction, we are routinely able to achieve high coating yields. We further describe … more
Date: December 1, 2010
Creator: Ron, Guy; Oort, Ron & Lee, Daniel
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Measurement of the Double-Beta Decay Half-life of {sup 136}Xe in KamLAND-Zen

Description: We present results from the KamLAND-Zen double-beta decay experiment based on an exposure of 77.6 days with 129 kg of {sup 136}Xe. The measured two-neutrino double-beta decay half-life of {sup 136}Xe is T{sup 2{nu}}{sub 1/2} = 2:38 {+-}#6; 0:02(stat)#6;{+-}0.14(syst)#2;x10{sup 21} yr, consistent with a recent measurement by EXO-200. We also obtain a lower limit for the neutrinoless double-beta decay half-life, T{sup 0{nu}}{sub 1/2} > 5.7 x#2; 10{sup 24} yr at 90% C.L.
Date: January 23, 2012
Creator: Collaboration, KamLAND-Zen; Gando, A.; Gando, Y.; Hanakago, H.; Ikeda, H.; Inoue, K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Approaching the Island of Inversion: 34P

Description: Yrast states in 34P were investigated using the 18O(18O,pn) reaction at energies of 20, 24, 25, 30, and 44 MeV at Florida State University and at Lawrence Berkeley National Laboratory. The level scheme was expanded, ray angular distributions were measured, and lifetimes were inferred with the Doppler-shift attenuation method by detecting decay protons in coincidence with one or more rays. The results provide a clearer picture of the evolution of structure approaching the 'Island of Inversion', … more
Date: June 14, 2011
Creator: Bender, P. C.; Hoffman, C. R.; Wiedeking, M.; Allmond, J. M.; Bernstein, L. A.; Burke, J. T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Integrating a Traveling Wave Tube into an AECR-U ion source

Description: An RF system of 500W - 10.75 to 12.75 GHz was designed and integrated into the Advanced Electron Cyclotron Resonance - Upgrade (AECR-U) ion source of the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The AECR-U produces ion beams for the Cyclotron giving large flexibility of ion species and charge states. The broadband frequency of a Traveling Wave Tube (TWT) allows modifying the volume that couples and heats the plasma. The TWT system design and integration with the AECR-U ion so… more
Date: July 1, 2011
Creator: Covo, Michel Kireeff; Benitez, Janilee Y.; Ratti, Alessandro & Vujic, Jasmina L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of the Younger Dryas Impact Layer

Description: We have uncovered a thin layer of magnetic grains and microspherules, carbon spherules, and glass-like carbon at nine sites across North America, a site in Belgium, and throughout the rims of 16 Carolina Bays. It is consistent with the ejecta layer from an impact event and has been dated to 12.9 ka BP coinciding with the onset of Younger Dryas (YD) cooling and widespread megafaunal extinctions in North America. At many locations the impact layer is directly below a black mat marking the sudden … more
Date: February 27, 2010
Creator: Firestone, Richard B.; West, Allen; Revay, Zsolt; Hagstrum, Jonathon T,; Belgya, Thomas; Hee, Shane S. Que et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Universality of Unintegrated Gluon Distributions at small x

Description: We systematically study dijet production in various processes in the small-x limit and establish an effective kt-factorization for hard processes in a system with dilute probes scattering on a dense target. In the large-Nc limit, the unintegrated gluon distributions involved in different processes are shown to be related to two widely proposed ones: the Weizsacker-Williams gluon distribution and the dipole gluon distribution.
Date: January 4, 2011
Creator: Dominguez, Fabio; Marquet, Cyrille; Xiao, Bowen & Yuan, Feng
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Initial and Final State Interaction Effects in Small-x Quark Distributions

Description: We study the initial and final state interaction effects in the transverse momentum dependent parton distributions in the small-x saturation region. In particular, we discuss the quark distributions in the semi-inclusive deep inelastic scattering, Drell-Yan lepton pair production and dijet-correlation processes in pA collisions. We calculate the quark distributions in the scalar-QED model and then extend to the color glass condensate formalism in QCD. The quark distributions are found universal… more
Date: August 30, 2010
Creator: Xiao, Bo-Wen & Yuan, Feng
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Capture Gamma-Ray Libraries for Nuclear Applications

Description: The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of d… more
Date: May 1, 2010
Creator: Sleaford, B.W.; Firestone, Richard B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A New Limit on Time-Reversal Violation in Beta Decay

Description: We report the results of an improved determination of the triple correlation DP {center_dot} (p{sub e} x p{sub v}) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the Standard Model. Our result is D = (-0.96 {+-} 1.89(stat) {+-} 1.01(sys)) x 10{sup -4}. The corresponding phase between g{sub A} and g{sub V} is {phi}{sub AV} = 180.013{sup o} {+-} 0.028{sup o} (68% confidence level). This result represents the most sen… more
Date: April 26, 2011
Creator: Mumm, H P; Chupp, T E; Cooper, R L; Coulter, K P; Freedman, S J; Fujikawa, B K et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Inclusive pi^0, eta, and direct photon production at high transverse momentum in p+p and d+Au collisions at sqrt(s_NN) = 200 GeV

Description: We report a measurement of high-p{sub T} inclusive {pi}{sup 0}, {eta}, and direct photon production in p + p and d + Au collisions at {radical}s{sub NN} = 200 GeV at midrapidity (0 < {eta} < 1). Photons from the decay {pi}{sup 0} {yields} {gamma}{gamma} were detected in the Barrel Electromagnetic Calorimeter of the STAR experiment at the Relativistic Heavy Ion Collider. The {eta} {yields} {gamma}{gamma} decay was also observed and constituted the first {eta} measurement by STAR. The first… more
Date: July 7, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Precision Measurement of Neutrino Oscillation Parameters with KamLAND

Description: This dissertation describes a measurement of the neutrino oscillation parameters #1;{Delta}m{sup 2}{sub 21}, θ{sub 12} and constraints on θ{sub 13} based on a study of reactor antineutrinos at a baseline of ∼ 180 km with the KamLAND detector. The data presented here was collected between April 2002 and November 2009, and amounts to a total exposure of 2.64 � 0.07 � 10{sup 32} proton-years. For this exposure we expect 2140 � 74(syst) antineutrino candidates from react… more
Date: December 12, 2011
Creator: KamLAND, & O'Donnell, Thomas
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Dihadron Azimuthal Correlation from Collins Effect in Unpolarized Hadron Collisions

Description: We study the dihadron azimuthal correlation produced nearly back-to-back in unpolarized hadron collisions, arising from the product of two Collins fragmentation functions. Using the latest Collins fragmentation functions extracted from the global analysis of available experimental data, we make predictions for the azimuthalcorrelation of two-pion production in pp collisions at RHIC energies. We find that the correlation is sizable in the mid-rapidity region for moderate jet transverse momentum.
Date: January 5, 2010
Creator: Yuan, Feng
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Systemsize dependence of associated yields in hadron-triggered jets

Description: We present results on the system size dependence of high transverse momentum di-hadron correlations at {radical}s{sub NN} = 200 GeV as measured by STAR at RHIC. Measurements in d+Au, Cu+Cu and Au+Au collisions reveal similar jet-like correlation yields at small angular separation ({Delta}{phi} {approx} 0, {Delta}{eta} {approx} 0) for all systems and centralities. Previous measurements have shown that the away-side yield is suppressed in heavy-ion collisions. We present measurements of the away-… more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Phases of Augmented Hadronic Light-Front Wave Functions

Description: It is an important question whether the final/initial state gluonic interactions which lead to naive-time-reversal-odd single-spin asymmetries and diffraction at leading twist can be associated in a definite way with the light-front wave function hadronic eigensolutions of QCD. We use light-front time-ordered perturbation theory to obtain augmented light-front wave functions which contain an imaginary phase which depends on the choice of advanced or retarded boundary condition for the gauge … more
Date: January 5, 2010
Creator: Yuan, Feng; Brodsky, S.J.; Pasquini, B. & Xiao, B.-W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The Energy Spectrum of Atmospheric Neutrinos between 2 and 200 TeV with the AMANDA-II Detector

Description: The muon and anti-muon neutrino energy spectrum is determined from 2000-2003 AMANDA telescope data using regularised unfolding. This is the first measurement of atmospheric neutrinos in the energy range 2-200 TeV. The result is compared to different atmospheric neutrino models and it is compatible with the atmospheric neutrinos from pion and kaon decays. No significant contribution from charm hadron decays or extraterrestrial neutrinos is detected. The capabilities to improve the measurement of… more
Date: May 11, 2010
Creator: Collaboration, IceCube & Abbasi, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Identified high-pT spectra in Cu+Cu collisions at sqrt sNN=200 GeV

Description: We report new results on identified (anti)proton and charged pion spectra at large transverse momenta (3 < p{sub T} < 10 GeV/c) from Cu+Cu collisions at {radical}s{sub NN} = 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC). This study explores the system size dependence of two novel features observed at RHIC with heavy ions: the hadron suppression at high-p{sub T} and the anomalous baryon to meson enhancement at intermediate transverse momenta. Both phenomena … more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Observation of pi+pi-pi+pi- photoproduction in ultraperipheral heavy-ion collisions at sqrt sNN = 200 GeV at the STAR detector

Description: We present a measurement of {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} photonuclear production in ultra-peripheral Au-Au collisions at {radical}s{sub NN} = 200 GeV from the STAR experiment. The {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} final states are observed at low transverse momentum and are accompanied by mutual nuclear excitation of the beam particles. The strong enhancement of the production cross section at low transverse momentum is consistent with coherent photoproduction. The {p… more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Long range rapidity correlations and jet production in high energy nuclear collisions

Description: The STAR Collaboration at RHIC presents a systematic study of high transverse momentum charged di-hadron correlations at small azimuthal pair separation {Delta}{phi}, in d+Au and central Au+Au collisions at {radical}s{sub NN} = 200 GeV. Significant correlated yield for pairs with large longitudinal separation {Delta}{eta} is observed in central Au+Au, in contrast to d+Au collisions. The associated yield distribution in {Delta}{eta} x {delta}{phi} can be decomposed into a narrow jet-like peak at… more
Date: July 5, 2010
Creator: STAR Collaboration
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electron and Photon Interactions in the Regime of Strong LPM Suppression

Description: Most searches for ultra-high energy (UHE) astrophysical neutrinos look for radio emission from the electromagnetic and hadronic showers produced in their interactions. The radio frequency spectrum and angular distribution depend on the shower development, so are sensitive to the interaction cross sections. At energies above about 1016 eV (in ice), the Landau-Pomeranchuk-Migdal (LPM) effect significantly reduces the cross sections for the two dominant electromagnetic interactions: bremsstrahlung… more
Date: June 10, 2010
Creator: Gerhardt, L. & Klein, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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