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Flavorful supersymmetry

Description: Weak scale supersymmetry provides elegant solutions to many of the problems of the standard model, but it also generically gives rise to excessive flavor and CP violation. We show that, if the mechanism that suppresses the Yukawa couplings also suppresses flavor changing interactions in the supersymmetry breaking parameters, essentially all the low energy flavor and CP constraints can be satisfied. The standard assumption of flavor universality in the supersymmetry breaking sector is not necessary. We study signatures of this framework at the LHC. The mass splitting among different generations of squarks and sleptons can be much larger than in conventional scenarios, and even the mass ordering can be changed. We find that there is a plausible scenario in which the next-to-lightest superparticle is a long-lived right-handed selectron or smuon which decays into the lightest superparticle, a gravitino. This leads to the spectacularsignature of monochromatic electrons or muons in a stopper detector, providing strong evidence for the framework.
Date: December 13, 2007
Creator: Nomura, Yasunori; Nomura, Yasunori; Papucci, Michele & Stolarski, Daniel
Partner: UNT Libraries Government Documents Department

Search for Ultra High-Energy Neutrinos with AMANDA-II

Description: A search for diffuse neutrinos with energies in excess of 10{sup 5} GeV is conducted with AMANDA-II data recorded between 2000 and 2002. Above 10{sup 7} GeV, the Earth is essentially opaque to neutrinos. This fact, combined with the limited overburden of the AMANDA-II detector (roughly 1.5 km), concentrates these ultra high-energy neutrinos at the horizon. The primary background for this analysis is bundles of downgoing, high-energy muons from the interaction of cosmic rays in the atmosphere. No statistically significant excess above the expected background is seen in the data, and an upper limit is set on the diffuse all-flavor neutrino flux of E{sup 2} {Phi}{sub 90%CL} < 2.7 x 10{sup -7} GeV cm{sup -2}s{sup -1} sr{sup -1} valid over the energy range of 2 x 10{sup 5} GeV to 10{sup 9} GeV. A number of models which predict neutrino fluxes from active galactic nuclei are excluded at the 90% confidence level.
Date: November 19, 2007
Creator: Collaboration, IceCube; Klein, Spencer & Ackermann, M.
Partner: UNT Libraries Government Documents Department

The Development of 6061-Aluminum Windows for the MICE LiquidAbsorber

Description: The thin windows for the Muon Ionization Cooling Experiment (MICE) liquid Absorber will be fabricated from 6061-T6-aluminum. The absorber and vacuum vessel thin windows are 300-mm in diameter and are 180 mm thick at the center. The windows are designed for an internal burst pressure of 0.68 MPa (100 psig) when warm. The MICE experiment design calls for changeable windows on the absorber, so a bolted window design was adopted. Welded windows offer some potential advantages over bolted windows when they are on the absorber itself. This report describes the bolted window and its seal. This report also describes an alternate window that is welded directly to the absorber body. The welded window design presented permits the weld to be ground off and re-welded. This report presents a thermal FEA analysis of the window seal-weld, while the window is being welded. Finally, the results of a test of a welded-window are presented.
Date: August 24, 2005
Creator: Lau, W.; Yang, S.Q.; Green, M.A.; Ishimoto, S. & Swanson, J.
Partner: UNT Libraries Government Documents Department

ATLAS TrackingEvent Data Model -- 12.0.0

Description: In this report the event data model (EDM) relevant for tracking in the ATLAS experiment is presented. The core component of the tracking EDM is a common track object which is suited to describe tracks in the innermost tracking sub-detectors and in the muon detectors in offline as well as online reconstruction. The design of the EDM was driven by a demand for modularity and extensibility while taking into account the different requirements of the clients. The structure of the track object and the representation of the tracking-relevant information are described in detail.
Date: July 23, 2006
Creator: ATLAS; Akesson, F.; Atkinson, T.; Costa, M.J.; Elsing, M.; Fleischmann, S. et al.
Partner: UNT Libraries Government Documents Department

MUON SOURCES, NEUTRINO FACTORY TO MU+- COLLIDERS.

Description: Employing intense muon sources to carry out forefront low energy research, such as the search for muon - number non-conservation, or for the purpose of providing intense high energy neutrino beams ({nu}factory) represents very interesting possibilities. If successful, such efforts would significantly advance the state of muon technology and provides intermediate steps in technologies required for a future high energy muon collider complex. High intensity muon: production, capture, cooling, acceleration and multiturn muon storage rings are some of the key technology issues that needs more studies and development. A muon collider require basically same number of muons as for the muon storage ring Neutrino Factory, but would require more cooling, and simultaneous capture of both {+-}{mu}. We present an overview of Muon Sources - Neutrino Factories, example of a muon storage ring at BNL, and possible upgrades to a full Muon Collider.
Date: June 10, 2000
Creator: PARSA,Z.
Partner: UNT Libraries Government Documents Department

MUON SOURCES, NEUTRINO FACTORY TO MU+- COLLIDERS.

Description: Employing intense muon sources to carry out forefront low energy research, such as the search for muon - number non-conservation, or for the purpose of providing intense high energy neutrino beams ({nu}factory) represents very interesting possibilities. If successful, such efforts would significantly advance the state of muon technology and provides intermediate steps in technologies required for a future high energy muon collider complex. High intensity muon: production, capture, cooling, acceleration and multiturn muon storage rings are some of the key technology issues that needs more studies and development. A muon collider require basically same number of muons as for the muon storage ring Neutrino Factory, but would require more cooling, and simultaneous capture of both {+-}{mu}. We present an overview of Muon Sources - Neutrino Factories, example of a muon storage ring at BNL, and possible upgrades to a full Muon Collider.
Date: June 10, 2000
Creator: Parsa, Z.
Partner: UNT Libraries Government Documents Department

HIGH ENERGY PHYSICS POTENTIAL AT MUON COLLIDERS

Description: In this paper, high energy physics possibilities and future colliders are discussed. The {mu}{sup +} {mu}{sup {minus}} collider and experiments with high intensity muon beams as the stepping phase towards building Higher Energy Muon Colliders (HEMC) are briefly reviewed and encouraged.
Date: April 7, 2000
Creator: Parsa, Z.
Partner: UNT Libraries Government Documents Department

Comments on frictional cooling and the zero energy options for cooling intense muon beams

Description: It is shown that the proposed frictional cooling method is not directly applicable to intense ({approximately} 10{sup 12}) muon bunches, mostly due to space charge constraints. Other difficulties stem from the fact that the initial emittance must be quite small, compared to the nominal muon collider emittance. Excessive heat due to energy deposition in the foils, from the primary muon beam or from secondary electrons could also destroy the thin foils used as moderator. Other zero energy schemes are considered, separately for {mu}{sup {minus}} and {mu}{sup +}. All of them lead the authors to the study of exotic electrons-ions-muons plasma.
Date: February 1, 2000
Creator: Lebrun, P.
Partner: UNT Libraries Government Documents Department

Muon Fluence Measurements for Homeland Security Applications

Description: This report focuses on work conducted at Pacific Northwest National Laboratory to better characterize aspects of backgrounds in RPMs deployed for homeland security purposes. Two polyvinyl toluene scintillators were utilized with supporting NIM electronics to measure the muon coincidence rate. Muon spallation is one mechanism by which background neutrons are produced. The measurements performed concentrated on a broad investigation of the dependence of the muon flux on a) variations in solid angle subtended by the detector; b) the detector inclination with the horizontal; c) depth underground; and d) diurnal effects. These tests were conducted inside at Building 318/133, outdoors at Building 331G, and underground at Building 3425 at Pacific Northwest National Laboratory.
Date: August 10, 2010
Creator: Ankney, Austin S.; Berguson, Timothy J.; Borgardt, James D. & Kouzes, Richard T.
Partner: UNT Libraries Government Documents Department

Thoughts on Incorporating HPRF in a Linear Cooling Channel

Description: We discuss a possible implementation of high-pressure gas-filled RF (HPRF) cavities in a linear cooling channel for muons and some of the technical issues that must be dealt with. The approach we describe is a hybrid approach that uses high-pressure hydrogen gas to avoid cavity breakdown, along with discrete LiH absorbers to provide the majority of the energy loss. Initial simulations show that the channel performs as well as the original vacuum RF channel while potentially avoiding the degradation in RF gradient associated with the strong magnetic field in the cooling channel.
Date: August 20, 2009
Creator: Gallardo, Juan C. & Zisman, Michael S
Partner: UNT Libraries Government Documents Department

Muon-induced backgrounds in the CUORICINO experiment

Description: To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO siteand operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV.kg.yr) (95percent c.l.) was obtained on the cosmicray induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.
Date: April 15, 2010
Creator: Andreotti, E.; Arnaboldi, C.; Avignone III, F. T.; Balata, M.; Bandac, I.; Barucci, M. et al.
Partner: UNT Libraries Government Documents Department

Neutrino Factory and Muon Collider Collaboration R and D Program

Description: The Neutrino Factory and Muon Collider Collaboration (MC) comprises some 140 scientists and engineers located at U.S. National Laboratories and Universities, and at a number of non-U.S. research institutions. In the past year, the MC R and D program has shifted its focus mainly toward the design issues related to the development of a Neutrino Factory based on a muon storage ring. In this paper the status of the various R and D activities is described, and future plans are outlined.
Date: July 1, 2000
Creator: Zisman, M.S.
Partner: UNT Libraries Government Documents Department

Complete Muon Cooling Channel Design and Simulations

Description: Considerable progress has been made in developing promising subsystems for muon beam cooling channels to provide the extraordinary reduction of emittances required for an energy-frontier muon collider. However, it has not yet been demonstrated that the various proposed cooling subsystems can be consolidated into an integrated end-to-end design. Presented here are concepts to address the matching of transverse emittances between subsystems through an extension of the theoretical framework of the Helical Cooling Channel (HCC), which allows a general analytical approach to guide the transition from one set of cooling channel parameters to another.
Date: July 1, 2012
Creator: C. Y. Yoshikawa, C.M. Ankenbrandt, R.P. Johnson, Y.S. Derbenev, V.S. Morozov, D.V. Neuffer, K. Yonehara
Partner: UNT Libraries Government Documents Department

SRF Cavity High-Gradient Study at 805 MHz for Proton and Other Applications

Description: 805 MHz elliptical SRF cavities have been used for SNS as the first application for protons. At LANL, an R&D started to explore a capability of getting high-gradient cavities (40-50 MV/m) at this frequency for the future applications such as proton and muon based interrogation testing facility added to the LANSCE accelerator and a power upgrade of the LANSCE accelerator for the fission and fusion material test station. Optimized cell designs for “standard”, “low-loss” and “re-entrant” shapes, cavity test results for “standard” single-cell cavities with temperature mapping as well as surface inspection results will be presented.
Date: May 1, 2009
Creator: Tajima, T; Chacon, P; Edwards, R L; Eremeev, G V; Krawczyk, F L; Roybal, R J et al.
Partner: UNT Libraries Government Documents Department

Multi-year search for a diffuse flxu of muon neutrinos with AMANDA-II

Description: A search for TeV-PeV muon neutrinos from unresolved sources was performed on AMANDA-II data collected between 2000 and 2003 with an equivalent livetime of 807 days. This diffuse analysis sought to find an extraterrestrial neutrino flux from sources with non-thermal components. The signal is expected to have a harder spectrum than the atmospheric muon and neutrino backgrounds. Since no excess of events was seen in the data over the expected background, an upper limit of E{sup 2}{Phi}{sub 90%C.L.} < 7.4 x 10{sup -8} GeV cm{sup -2} s{sup -1} sr{sup -1} is placed on the diffuse flux of muon neutrinos with a {Phi} {proportional_to} E{sup -2} spectrum in the energy range 16 TeV to 2.5 PeV. This is currently the most sensitive {Phi} {proportional_to} E{sup -2} diffuse astrophysical neutrino limit. We also set upper limits for astrophysical and prompt neutrino models, all of which have spectra different than {Phi} {proportional_to} E{sup -2}.
Date: April 13, 2008
Creator: Collaboration, IceCube; Klein, Spencer; Achterberg, A. & Collaboration, IceCube
Partner: UNT Libraries Government Documents Department

Calculating the Muon Cooling within a MICE Solid and LiquidAbsorber

Description: The key elements of the Muon Ionization Cooling Experiment (MICE) cooling channel are the absorbers that are a part of the MICE absorber focus coil modules (AFC modules). The boundaries of room temperature solid absorbers are well defined. The density of most solid absorber materials is also well understood. The properties of solid absorber are most certainly understood to 0.3 percent. The MICE liquid absorbers are different in that their dimensions are a function of the absorber temperature and the fluid pressure within the absorber. The second element in the liquid absorber is the variability of the liquid density with temperature and pressure. While one can determine the absorber boundary within 0.3 percent, the determination of the liquid density within 0.3 percent is more difficult (particularly with liquid helium in the absorber). This report presents a method of calculating absorber boundary and the cooling performance of the MICE absorbers as a function of fluid temperature and pressure.
Date: June 10, 2006
Creator: Yang, Stephanie Q.; Green, Michael A. & Virostek, Steve P.
Partner: UNT Libraries Government Documents Department

Alignment of the Pixel and SCT Modules for the 2004 ATLAS Combined Test Beam

Description: A small set of final prototypes of the ATLAS Inner Detector silicon tracking system(Pixel Detector and SemiConductor Tracker), were used to take data during the 2004 Combined Test Beam. Data were collected from runs with beams of different flavour (electrons, pions, muons and photons) with a momentum range of 2 to 180 GeV/c. Four independent methods were used to align the silicon modules. The corrections obtained were validated using the known momenta of the beam particles and were shown to yield consistent results among the different alignment approaches. From the residual distributions, it is concluded that the precision attained in the alignmentof the silicon modules is of the order of 5 mm in their most precise coordinate.
Date: June 2, 2008
Creator: Collaboration, ATLAS; Ahmad, A.; Andreazza, A.; Atkinson, T.; Baines, J.; Barr, A.J. et al.
Partner: UNT Libraries Government Documents Department

Alignment strategy for the ATLAS tracker

Description: The ATLAS experiment is a multi-purpose particle detector that will study high-energy particle collisions produced by the Large Hadron Collider. For the reconstruction of charged particles, and their production and their decay vertices, ATLAS is equipped with a sophisticated tracking system, unprecedented in size and complexity. Full exploitation of both the Inner Detector and the muon spectrometer requires an accurate alignment. The challenge of aligning the ATLAS tracking devices is discussed, and the ATLAS alignment strategy is presented and illustrated with both data and Monte Carlo results.
Date: September 23, 2007
Creator: ATLAS & Golling, T.
Partner: UNT Libraries Government Documents Department

Complete Muon Cooling Channel Design and Simulations

Description: Considerable progress has been made in developing promising subsystems for muon beam cooling channels to provide the extraordinary reduction of emittances required for an energy-frontier muon collider. However, it has not yet been demonstrated that the various proposed cooling subsystems can be consolidated into an integrated end-to-end design. Presented here are concepts to address the matching of transverse emittances between subsystems through an extension of the theoretical framework of the Helical Cooling Channel (HCC), which allows a general analytical approach to guide the transition from one set of cooling channel parameters to another.
Date: May 1, 2012
Creator: Neuffer, D.V.; /Fermilab; Ankenbrandt, C.M.; Johnson, R.P.; Yoshikawa, C.Y.; /MUONS Inc., Batavia et al.
Partner: UNT Libraries Government Documents Department

RECENT RESULTS FROM OPTIMIZATION STUDIES OF LINEAR NON-SCALING FFAGs FOR MUON ACCELERATION.

Description: Because of the highly repetitive nature and simple cell structure of FFAG lattices, it is possible to automatically design these lattices. In designing an FFAG lattice, one will try to meet certain constraints and then minimize some cost function by varying any remaining free parameters. I will first review previously published work on optimized FFAG design. Then I will describe recent advances in the understanding of linear non-scaling FFAG design that have come from these optimization techniques. I will describe how the lattice designs depend on some input parameters to the design. Finally, I will present a set of FFAG lattices that are optimized for muon acceleration using these techniques.
Date: October 13, 2004
Creator: BERG,J.S.
Partner: UNT Libraries Government Documents Department

Observation of a narrow mass state decaying into $\Upsilon(1S) + \gamma$ in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV

Description: Using data corresponding to an integrated luminosity of 1.3 fb{sup -1}, we observe a narrow mass state decaying into {Upsilon}(1S) + {gamma}, where the {Upsilon}(1S) meson is detected by its decay into a pair of oppositely charged muons, and the photon is identified through its conversion into an electron-positron pair. The significance of this observation is 5.6 standard deviations. The mass of the state is centered at 10.551 {+-} 0.014(stat.) {+-} 0.017(syst.) GeV/c{sup 2}, which is consistent with that of the state recently observed by the ATLAS Collaboration.
Date: March 1, 2012
Creator: Abazov, Victor Mukhamedovich & al., et
Partner: UNT Libraries Government Documents Department