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Semileptonic Decays and Sides of the Unitarity Triangle

Description: The elements of the CKM matrix enter the expressions for the decay rates and mixing amplitudes of hadrons. In some cases, the theoretical expressions are free of strong interaction effects, for example the CP asymmetry in B {yields} J/{psi} K{sub S}{sup 0}, so that measuring the CP asymmetry directly gives the value of sin 2{beta}, with the error in the result given by the experimental error in the measurement. In most cases, however, the experimentally measured quantities depend on strong inte… more
Date: May 1, 2003
Creator: Ligeti, Zoltan; Bauer, C.; Bernard, C.; Bigi, I.; Datta, M.; del Re, D. et al.
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Partner: UNT Libraries Government Documents Department
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J/(ps) Production via Initial State Radiation in e+e- ----> (m)+(m)-y at an e+e- Center-of-Mass Energy near 10.6 GeV

Description: The authors have used a study of the process e{sup +}e{sup -} {yields} {mu}{sup +}{mu}{sup -} {gamma} at a center-of-mass energy near the {Upsilon}(4S) resonance for a {mu}{sup +}{mu}{sup -} invariant mass range near the J/{psi} mass to extract the cross section {sigma}(e{sup +}e{sup -} {yields} J/{psi}{gamma} {yields} {mu}{sup +}{mu}{sup -}{gamma}). The data set, corresponding to an integrated luminosity of 88.4 fb{sup -1}, was collected using the BABAR detector at the PEP-II collider. They me… more
Date: November 13, 2003
Creator: Wright, D & Collaboration, T B
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Partner: UNT Libraries Government Documents Department
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Jet-Induced Star Formation

Description: Jets from radio galaxies can have dramatic effects on the medium through which they propagate. We review observational evidence for jet-induced star formation in low ('FR-I') and high ('FR-II') luminosity radio galaxies, at low and high redshifts respectively. We then discuss numerical simulations which are aimed to explain a jet-induced starburst ('Minkowski's Object') in the nearby FR-I type radio galaxy NGC 541. We conclude that jets can induce star formation in moderately dense (10 cm{sup -… more
Date: December 16, 2003
Creator: van Breugel, W.; Fragile, C.; Anninos, P. & Murray, S.
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Partner: UNT Libraries Government Documents Department
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Mechanical Design of a Second Generation LHC IR Quadrupole

Description: One of the proposed options to increase the LHC luminosity is the replacement of the existing inner triplets at the Interaction Regions with new low-beta larger aperture quadrupoles operating at the same gradient. Lawrence Berkeley National Laboratory (LBNL) is carrying out preliminary studies of a large-bore Nb{sub 3}Sn quadrupole. The mechanical design presents a support structure based on the use of keys and bladders without self-supporting collars. This technology has been proven effective … more
Date: November 10, 2003
Creator: Caspi, S.; Bartlett, S. E.; Dietderich, D. R.; Ferracin, P.; Gourlay, S. A.; Hafalia, R. R. et al.
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Partner: UNT Libraries Government Documents Department
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Deutron photodissociation in ultraperipheral relativistic heavyion on deutron collisions

Description: In ultraperipheral relativistic deuteron on heavy-ion collisions, a photon emitted from the heavy nucleus may dissociate the deuterium ion. We find deuterium breakup cross sections of 1.24 barns for deuterium-gold collisions at a center of mass energy of 200 GeV per nucleon, as studied at the Relativistic Heavy Ion Collider, and 2.35 barns for deuterium-lead collisions at a center of mass energy of 6.2 TeV, as proposed for the Large Hadron Collider. In the latter case, the cross section is as l… more
Date: March 24, 2003
Creator: Klein, Spencer & Vogt, Ramona
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Partner: UNT Libraries Government Documents Department
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Damping ring designs and issues

Description: The luminosity performance of a future linear collider (LC) will depend critically on the performance of the damping rings. The design luminosities of the current LC proposals require rings with very short damping times, large acceptance, low equilibrium emittance and high beam intensity. We discuss the design strategies for lattices achieving the goals of dynamical stability, examine the challenges for alignment and coupling correction, and consider a variety of collective effects that threate… more
Date: May 12, 2003
Creator: Wolski, Andrzej & Decking, Winfried
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Partner: UNT Libraries Government Documents Department
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Progress of the PEP-II-B-factory

Description: PEP-II is an e{sup +}e{sup -} B-Factory Collider located at SLAC operating at the Upsilon 4S resonance. PEP-II has delivered, over the past five years, an integrated luminosity to the BaBar detector of over 139 fb{sup -1} and has reached a luminosity of 6.58 x 10{sup 36}/cm{sup 2}/s. Steady progress is being made in reaching higher luminosity. The goal over the next several years is to reach a luminosity of at least 2 x 10{sup 34}/cm{sup 2}/s. The accelerator physics issues being addressed in P… more
Date: June 1, 2003
Creator: Seeman, J.; Browne, M.; Cai, Y.; Colocho, W.; Decker, F.-J.; Donald, M. et al.
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Partner: UNT Libraries Government Documents Department
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Searches for new physics at D0

Description: The integrated luminosity at Run 2 of the Tevatron is approaching the Run 1 total, and data analysis is progressing. New results in searches for new physics by the D0 experiment are presented in a variety of channels, demonstrating good performance of the detector and detailed understanding of the data.
Date: June 4, 2003
Creator: Brooijmans, Gustaaf
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Partner: UNT Libraries Government Documents Department
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Aging tests of full scale CMS muon cathode strip chambers

Description: Two CMS production Cathode Strip Chambers were tested for aging effects in the high radiation environment at the Gamma Irradiation Facility at CERN. The chambers were irradiated over a large area: in total, about 2.1 m{sup 2} or 700 m of wire in each chamber. The 40% Ar+50%CO{sub 2}+10%CF{sub 4} gas mixture was provided by an open-loop gas system for one of the chambers and by closed-loop recirculating gas system for the other. After accumulating 0.3-0.4 C per centimeter of a wire, which is equ… more
Date: October 15, 2003
Creator: al., D. Acosta et
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Partner: UNT Libraries Government Documents Department
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Lattice function measurements of the Fermilab recycler ring

Description: The Fermilab Recycler ring, designed and built as an 8-GeV anti-proton storage ring, is at the final stage of its commissioning. Once integrated into the accelerator complex it is expected to help achieve the luminosity goal of Run II at Fermilab. The Recycler Ring is made up mostly of combined function magnets with a substantial sextupole component. Any orbit error could cause higher order feed-down and potentially change the machine. Lattice function measurements had been taken at various sta… more
Date: June 4, 2003
Creator: Yang, Ming-Jen; Marchionni, Alberto & Mishra, Shekhar
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Partner: UNT Libraries Government Documents Department
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Barrier RF stacking at Fermilab

Description: A key issue to upgrade the luminosity of the Tevatron Run2 program and to meet the neutrino requirement of the NuMI experiment at Fermilab is to increase the proton intensity on the target. This paper introduces a new scheme to double the number of protons from the Main Injector (MI) to the pbar production target (Run2) and to the pion production target (NuMI). It is based on the fact that the MI momentum acceptance is about a factor of four larger than the momentum spread of the Booster beam. … more
Date: June 4, 2003
Creator: al., Weiren Chou et
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Partner: UNT Libraries Government Documents Department
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New aspects of beam-beam interactions in hadron colliders

Description: Beam-beam phenomena have until now limited the beam currents and luminosity achievable in the Tevatron. injected proton currents are about ten times larger than the anti-proton currents so beam-beam effects have largely acted on the anti-protons and at all stages of the operational cycle. The effects of the anti-protons on the protons have until now been relatively benign but that may change at higher anti-proton currents. After 36 bunches of protons are injected and placed on the proton helix,… more
Date: June 2, 2003
Creator: Sen, Tanaji
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Partner: UNT Libraries Government Documents Department
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Palomar 5 and its tidal tails: New observational results

Description: Sloan Digital Sky Survey data for the field of the cluster Pal 5 reveal the existence of a long massive stream of tidal debris spanning an arc of 10{sup o} on the sky. Pal 5 thus provides an outstanding example for tidal disruption of globular clusters in the Milky Way. Radial velocities from VLT spectra show that Pal 5 has an extremely low velocity dispersion, in accordance with the very low mass derived from its total luminosity.
Date: February 6, 2003
Creator: al., M. Odenkirchen et
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Partner: UNT Libraries Government Documents Department
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First D-Zero jet measurements at squareroot s =1.96 TeV

Description: The authors present the first Run II measurements with the D0 detector of the inclusive jet and dijet cross sections at {radical}s = 1.96 TeV. This analysis is based on an integrated luminosity of 34 pb{sup -1}. The results from a next-to-leading order perturbative QCD calculation are compared to the measured cross sections. The theoretical calculation agrees with the data.
Date: September 25, 2003
Creator: Begel, Michael
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Partner: UNT Libraries Government Documents Department
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Searches at the Run II Tevatron Collider

Description: Some initial results based on 40-90 pb{sup -1} of integrated luminosity from Run II are presented for searches for new phenomena beyond the Standard Model, conducted at the upgraded Tevatron CDF and D0 experiments.
Date: September 30, 2003
Creator: Groer, Leslie Stevan
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Partner: UNT Libraries Government Documents Department
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Observations on the luminosity lifetimes, emittance growth rates and intra-beam scattering at the Tevatron

Description: A record luminosity of 4.2 10{sup 31}has been reached at the Fermilab p-{bar p} collider. The lifetime of this luminosity at the beginning of the store is about 10 hours. This lifetime can be explained by the measured loss of anti-protons and protons due to collisions and emittance growths. We report on transverse emittance growth rates based on our Synchrotron Light Monitor. Longitudinal emittance growth rate measurements are based on the TeV Sampled Bunch Display data. It is shown that Intra … more
Date: May 22, 2003
Creator: al., Paul L.G. Lebrun et
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Partner: UNT Libraries Government Documents Department
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The readout of the LHC beam luminosity monitor: Accurate shower energy measurements at a 40 MHz repetition rate

Description: The LHC beam luminosity monitor is based on the following principle. The neutrals that originate in LHC at every PP interaction create showers in the absorbers placed in front of the cryogenic separation dipoles. The shower energy, as it can be measured by suitable detectors in the absorbers is proportional to the number of neutral particles and, therefore, to the luminosity. This principle lends itself to a luminosity measurement on a bunch-by-bunch basis. However, detector and front-end elect… more
Date: May 10, 2003
Creator: Manfredi, P.F.; Ratti, L.; Speziali, V.; Traversi, G.; Manghisoni, M.; Re, V. et al.
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Partner: UNT Libraries Government Documents Department
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Fermilab recycler stochastic cooling commissioning and performance

Description: The Fermilab Recycler is a fixed 8 GeV kinetic energy storage ring located in the Fermilab Main Injector tunnel near the ceiling. The Recycler has two roles in Run II. First, to store antiprotons from the Fermilab Antiproton Accumulator so that the antiproton production rate is no longer compromised by large numbers of antiprotons stored in the Accumulator. Second, to receive antiprotons from the Fermilab Tevatron at the end of luminosity periods. To perform each of these roles, stochastic cool… more
Date: June 4, 2003
Creator: Broemmelsiek, D. & Pasquinelli, Ralph
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Partner: UNT Libraries Government Documents Department
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High luminosity operation of the Fermilab accelerator complex

Description: Run-II at Fermilab is progressing steadily. In the Run-II scheme, 36 antiproton bunches collide with 36 proton bunches at the CDF and D0 interaction regions in the Tevatron at 980 GeV per beam. The current status and performance of the Fermilab Accelerator complex is reviewed. The plan for Run-II, accelerator upgrades and integration of the Recycler in the accelerator chain will be presented.
Date: July 15, 2003
Creator: Mishra, Shekhar
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Partner: UNT Libraries Government Documents Department
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Jet Production at CDF

Description: The Run 2 at Tevatron will define a new level of precision for QCD studies in hadron collisions. Both collider experiments, CDF and D0, expect to collect up to 15 fb{sup -1} of data in this new run period. The increase in instantaneous luminosity, center-of-mass energy (from 1.8 TeV to 2 TeV) and the improved acceptance of the detectors will allow stringent tests of the Standard Model (SM) predictions in extended regions of jet transverse energy, E{sub T}{sup jet}, and jet pseudorapidity, {eta}… more
Date: January 15, 2003
Creator: Martinez, M.
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Partner: UNT Libraries Government Documents Department
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Run II physics at the Fermilab Tevatron and advanced analysis methods

Description: The Fermilab Tevatron has the unique opportunity to explore physics at the electroweak scale with the highest ever proton-antiproton collision energy of {radical}s = 1.96 TeV and unprecedented luminosity. About 20 times more data is expected to be collected during the first phase of the collider Run II which is in its second year of data-taking. The second phase of Run II, expected to begin in 2005, will increase the integrated luminosity to about 10-15 fb{sup -1}. Discovering a low mass Higgs … more
Date: June 23, 2003
Creator: Bhat, Pushpalatha C
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Partner: UNT Libraries Government Documents Department
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A new antiproton beam transfer scheme without coalescing

Description: An effective way to increase the luminosity in the Fermilab Tevatron collider program Run2 is to improve the overall antiproton transfer efficiency. During antiproton coalescing in the Main Injector (MI), about 10-15% particles get lost. This loss could be avoided in a new antiproton transfer scheme that removes coalescing from the process. Moreover, this scheme would also eliminate emittance dilution due to coalescing. This scheme uses a 2.5 MHz RF system to transfer antiprotons from the Accum… more
Date: June 4, 2003
Creator: al., Weiren Chou et
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Partner: UNT Libraries Government Documents Department
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Beam physics at Tevatron complex

Description: The challenge of achieving the Tevatron Run II luminosity goal of 3 {center_dot} 10{sup 32} cm{sup -2} s{sup -1} requires high level of engineering and machine operation, good and reliable diagnostics, and clear understanding of the underlying accelerator physics. Recent history demonstrated steady increase of the Tevatron luminosity, which was supported by each of the three listed above items. This report reviews major developments in the accelerator physics, which contributed in the Run II lu… more
Date: May 28, 2003
Creator: Lebedev, Valeri A.
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Partner: UNT Libraries Government Documents Department
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