WorldWideScience

Sample records for collider restart delayed

  1. Design flaw could delay collider

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "A magnet for the Large Hadron Collider (LHC) failed during a key test at the European particle physics laboratory CERN last week. Physicists and engineers will have to repair the damaged manget and retrofil others to correct the underlying design flaw.."(1 page)

  2. More bad connections may limit LHC energy or delay restart

    CERN Multimedia

    Cho, Adrian

    2009-01-01

    "Last September, the world's highest-engery particle smasher - the Large Hadron Collider, or LHC - mangled itself when a splice in a superconducting electrical line melted and set off a chain reaction of mechanical failure [..]. Since then, physicists here at the European particle physics laboratory, Cern, have installed exquisitely sensitive warning systems to monitor the delicate splices and head off a similar catastrophe" (1.5 pages)

  3. Anthrax vaccine adsorbed: further evidence supporting continuing the vaccination series rather than restarting the series when doses are delayed.

    Science.gov (United States)

    Pittman, Phillip R; Cavicchia, M A; Kingsbury, J L; Johnson, N A; Barrera-Oro, J G; Schmader, T; Korman, L; Quinn, X; Ranadive, M

    2014-09-03

    Whether to restart or continue the series when anthrax vaccine doses are missed is a frequent medical management problem. We applied the noninferiority analysis model to this prospective study comparing the Bacillus anthracis protective antigen (PA) IgG antibody response and lethal toxin neutralization activity at day 28 to the anthrax vaccine adsorbed (AVA) (Biothrax®) administered on schedule or delayed. A total of 600 volunteers were enrolled: 354 in the on-schedule cohort; 246 in the delayed cohort. Differences were noted in immune responses between cohorts (panthrax vaccine are delayed as long as 5 or more years.

  4. Beleaguered LHC gears up for restart

    CERN Multimedia

    Cartwright, Jon

    2009-01-01

    "The Large Hadron Collider (LHC) is finally set to restart in mid-November following last year's accident. Initially it will collide protons at an energy of only 3.5 TeV per beam, and staff at Cern will have to wait until late next year before trying to run the collider at its maximum energy" (0.75 page)

  5. COLLIDE

    CERN Multimedia

    2017-01-01

    Howie Day, Collide, Based on the original parody "Collide" by USLHC, inspired by the original song "Collide" written by Howie Day and Kevin Griffin. Re-record Produced by Mike Denneen Engineered by Patrick DiCenso -Vocals, Guitars, Keyboards- Howie Day -Guitar Patrick DiCenso -Bass- Ed Valuskas -Drums- Dave Brophy

  6. Colliders

    CERN Document Server

    Chou, Weiren

    2014-01-01

    The idea of colliding two particle beams to fully exploit the energy of accelerated particles was first proposed by Rolf Wideröe, who in 1943 applied for a patent on the collider concept and was awarded the patent in 1953. The first three colliders — AdA in Italy, CBX in the US, and VEP-1 in the then Soviet Union — came to operation about 50 years ago in the mid-1960s. A number of other colliders followed. Over the past decades, colliders defined the energy frontier in particle physics. Different types of colliers — proton–proton, proton–antiproton, electron–positron, electron–proton, electron-ion and ion-ion colliders — have played complementary roles in fully mapping out the constituents and forces in the Standard Model (SM). We are now at a point where all predicted SM constituents of matter and forces have been found, and all the latest ones were found at colliders. Colliders also play a critical role in advancing beam physics, accelerator research and technology development. It is timel...

  7. First Passage under Restart

    Science.gov (United States)

    Pal, Arnab; Reuveni, Shlomi

    2017-01-01

    First passage under restart has recently emerged as a conceptual framework suitable for the description of a wide range of phenomena, but the endless variety of ways in which restart mechanisms and first passage processes mix and match hindered the identification of unifying principles and general truths. Hope that these exist came from a recently discovered universality displayed by processes under optimal, constant rate, restart—but extensions and generalizations proved challenging as they marry arbitrarily complex processes and restart mechanisms. To address this challenge, we develop a generic approach to first passage under restart. Key features of diffusion under restart—the ultimate poster boy for this wide and diverse class of problems—are then shown to be completely universal.

  8. Replication Restart in Bacteria.

    Science.gov (United States)

    Michel, Bénédicte; Sandler, Steven J

    2017-07-01

    In bacteria, replication forks assembled at a replication origin travel to the terminus, often a few megabases away. They may encounter obstacles that trigger replisome disassembly, rendering replication restart from abandoned forks crucial for cell viability. During the past 25 years, the genes that encode replication restart proteins have been identified and genetically characterized. In parallel, the enzymes were purified and analyzed in vitro, where they can catalyze replication initiation in a sequence-independent manner from fork-like DNA structures. This work also revealed a close link between replication and homologous recombination, as replication restart from recombination intermediates is an essential step of DNA double-strand break repair in bacteria and, conversely, arrested replication forks can be acted upon by recombination proteins and converted into various recombination substrates. In this review, we summarize this intense period of research that led to the characterization of the ubiquitous replication restart protein PriA and its partners, to the definition of several replication restart pathways in vivo, and to the description of tight links between replication and homologous recombination, responsible for the importance of replication restart in the maintenance of genome stability. Copyright © 2017 American Society for Microbiology.

  9. Delay in Europe could mean extra year for U.S. Collider

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "Physicists were hardly surprised when officials at the European lab CERN announced last week that the world's new highest-energy atom smasher, the Large Hadron Collider (LHC), will not start up in November as planned..."(1 page)

  10. A multi-moded rf delay line distribution system for the next linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Tantawi, S.G.; Bowden, G.; Farkas, Z.D.; Irwin, J.; Ko, K.; Kroll, N.; Lavine, T.; Li, Z.; Loewen, R.; Miller, R.; Nantista, C.; Ruth, R.D.; Rifkin, J.; Vlieks, A.E.; Wilson, P.B.; Adolphsen, C.; Wang, J. [Stanford Linear Accelerator Center, SLAC, 2575 Sand Hill Rd, Mento Park, California 94025 (United States)

    1999-07-01

    The Delay Line Distribution System (DLDS) (1) is an alternative to conventional pulse compression which enhances the peak power of an rf source while matching the long pulse of that source to the shorter filling time of the accelerator structure. We present a variation on that scheme that combines the parallel delay lines of the system into one single line. The power of several sources is combined into a single waveguide delay line using a multi-mode launcher. The output mode of the launcher is determined by the phase coding of the input signals. The combined power is extracted using several mode extractors, each of which extracts only one single mode. Hence, the phase coding of the sources controls the output port of the combined power. The power is then fed to the local accelerator structures. We present a detailed design of such a system, including several implementation methods for the launchers, extractors, and ancillary high power rf components. The system is designed so that it can handle the 600 MW peak power required by the NLC design, while maintaining high efficiency. {copyright} {ital 1999 American Institute of Physics.}

  11. Particle collider magnet failure blamed on faulty engineering Experts are still weighing whether the hitch will delay the start-up of the Large Hadron Collider

    CERN Multimedia

    2007-01-01

    "Researchers have identified the cause of a hiccup in the construction of the world's next top particle smasher, the Large Hadron Collider (LHC). During stress tests last week at the European Laboratory for Particle Physics (CERN), a support structure tore loose from the housing of a keay ultracold magnet."(1 page)

  12. Press Conference: LHC Restart, Season 2

    CERN Document Server

    CERN. Geneva

    2015-01-01

    PRESS BRIEFING ON THE LARGE HADRON COLLIDER (LHC) RE-START, SEASON 2 AT CERN, GLOBE OF SCIENCE AND INNOVATION Where :   http://cern.ch/directions   at the Globe of Science and Innovation When : Thursday, 12 March from 2.30 to 3.30pm - Open seating as from 2.15pm Speakers : CERN’s Director General, Rolf Heuer and Director of Accelerators, Frédérick Bordry, and representatives of the LHC experiments Webcast : https://webcast.web.cern.ch/webcast/ Dear Journalists, CERN is pleased to invite you to the above press briefing which will take place on Thursday 12 March, in the Globe of Science and Innovation, 1st floor, from 2.30 to 3.30pm. The Large Hadron Collider (LHC) is ready to start up for its second three-year run. The 27km LHC is the largest and most powerful particle accelerator in the world operating at a temperature of -217 degrees Centigrade and powered to a current of 11,000 amps. Run 2 of the LHC follows a two-year technical s...

  13. Optimality of Non-Restarting CUSUM charts

    OpenAIRE

    2012-01-01

    We show optimality, in a well-defined sense, using cumulative sum (CUSUM) charts for detecting changes in distributions. We consider a setting with multiple changes between two known distributions. This result advocates the use of non-restarting CUSUM charts with an upper boundary. Typically, after signalling, a CUSUM chart is restarted by setting it to some value below the threshold. A non-restarting CUSUM chart is not reset after signalling; thus is able to signal continuously. Imposing an ...

  14. LHC Report: Restart preparations continue

    CERN Multimedia

    Katy Foraz for the LHC team and Julia Trummer for the RP Group

    2012-01-01

    Maintenance and consolidation work has been progressing well in both the machine and the experiments in preparation for the March restart.   A sample material is attached to the LHC (the white bag taped to the green line), to measure the radiation doses. Additional work was required around Point 5 due to the discovery and repair of a problem with the RF fingers at the connection of two beam vacuum chambers in CMS. The repair has been completed successfully and the sector is now under vacuum. In order to avoid rushing the delicate final operations required for closing the detector, the restart of the machine has been postponed by one week, from 7 March to 14 March. In the machine, the first cool-down to 1.9 K has started in several sectors ,and the cool-down of the whole machine is still planned to be finished by 21 February. The time window between 22 February and 14 March will be dedicated to powering and cryogenic tests. Since 12 December, the Radiation Protection (RP) group has been deep...

  15. TOTEM and LHCf: refinements for the restart

    CERN Multimedia

    2009-01-01

    Following the previous two issues, the Bulletin continues its series to find out what the six LHC experiments have been up to since last September, and how they are preparing for the restart. We covered CMS, ATLAS, LHCb and ALICE in previous issues. In this issue we will round up the past 10 months of activity at TOTEM and LHCf. Roman Pots of the TOTEM experiment.TOTEM The past 10 months at TOTEM have been amongst the busiest since the project’s inception. The delay in the LHC startup has certainly had a silver lining for the TOTEM collaboration - not only has it given them a much-needed opportunity to test and install many crucial new detector parts, but also the lower energy range that the LHC will initially operate at in 2009 is perfect for TOTEM physics. "In fact, the LHC almost seems to be following the schedule of TOTEM!" jokes Karsten Eggert, TOTEM spokesperson. TOTEM is made up of three different detectors spread out...

  16. LHC Report: A tough restart

    CERN Multimedia

    Jan Uythoven for the LHC team

    2012-01-01

    The third LHC Technical Stop of five days took place in the week of September 17. Getting back to normal operation after a technical stop  can sometimes be difficult, with debugging, testing and requalification required on the systems that have seen interventions. Folding in a selection of other problems can make for a frustrating time.   The new injector magnet is transported to the LHC. Photo: TE/ABT group. The restart experienced over the last days was one of the tougher ones. Many problems occurred, both small and large, one after the other; in the end it took until Sunday afternoon, 9 days after the end of the technical stop, to have a physics fill in the machine that delivered an initial luminosity similar to those before the technical stop. Most problems encountered were, in fact, not related to the technical stop. The technical stop consisted of the usual maintenance and consolidation of the various systems, but two items stand out: the replacement of the mirrors an...

  17. Muon colliders

    Science.gov (United States)

    Palmer, R. B.; Sessler, A.; Skrinsky, A.; Tollestrup, A.; Baltz, A. J.; Chen, P.; Cheng, W.-H.; Cho, Y.; Courant, E.; Fernow, R. C.; Gallardo, J. C.; Garren, A.; Green, M.; Kahn, S.; Kirk, H.; Lee, Y. Y.; Mills, F.; Mokhov, N.; Morgan, G.; Neuffer, D.; Noble, R.; Norem, J.; Popovic, M.; Schachinger, L.; Silvestrov, G.; Summers, D.; Stumer, I.; Syphers, M.; Torun, Y.; Trbojevic, D.; Turner, W.; Van Ginneken, A.; Vsevolozhskaya, T.; Weggel, R.; Willen, E.; Winn, D.; Wurtele, J.

    1996-05-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity μ+μ- colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Problems of detector background are also discussed.

  18. Muon colliders

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, R.B. [Brookhaven National Lab., Upton, NY (United States)]|[Stanford Linear Accelerator Center, Menlo Park, CA (United States); Sessler, A. [Lawrence Berkeley Lab., CA (United States); Skrinsky, A. [BINP, RU-630090 Novosibirsk (Russian Federation)] [and others

    1996-01-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity {micro}{sup +}{micro}{sup {minus}}colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Problems of detector background are also discussed.

  19. LHC Experiments: refinements for the restart

    CERN Multimedia

    2009-01-01

    As the LHC restart draws closer, the Bulletin will be taking a look at how the six LHC experiments are preparing and what they have been up to since last September. In this issue we start with a roundup of the past 10 months of activity at CMS and ATLAS, both technical work and outreach activities.

  20. A technique for accelerating the convergence of restarted GMRES

    Energy Technology Data Exchange (ETDEWEB)

    Baker, A H; Jessup, E R; Manteuffel, T

    2004-03-09

    We have observed that the residual vectors at the end of each restart cycle of restarted GMRES often alternate direction in a cyclic fashion, thereby slowing convergence. We present a new technique for accelerating the convergence of restarted GMRES by disrupting this alternating pattern. The new algorithm resembles a full conjugate gradient method with polynomial preconditioning, and its implementation requires minimal changes to the standard restarted GMRES algorithm.

  1. A technique for accelerating the convergence of restarted GMRES

    Energy Technology Data Exchange (ETDEWEB)

    Baker, A H; Jessup, E R; Manteuffel, T

    2004-03-09

    We have observed that the residual vectors at the end of each restart cycle of restarted GMRES often alternate direction in a cyclic fashion, thereby slowing convergence. We present a new technique for accelerating the convergence of restarted GMRES by disrupting this alternating pattern. The new algorithm resembles a full conjugate gradient method with polynomial preconditioning, and its implementation requires minimal changes to the standard restarted GMRES algorithm.

  2. Promoting Recruitment using Information Management Efficiently (PRIME): study protocol for a stepped-wedge cluster randomised controlled trial within the REstart or STop Antithrombotics Randomised Trial (RESTART).

    Science.gov (United States)

    Maxwell, Amy E; Dennis, Martin; Rudd, Anthony; Weir, Christopher J; Parker, Richard A; Al-Shahi Salman, Rustam

    2017-03-01

    Research into methods to boost recruitment has been identified as the highest priority for randomised controlled trial (RCT) methodological research in the United Kingdom. Slow recruitment delays the delivery of research and inflates costs. Using electronic patient records has been shown to boost recruitment to ongoing RCTs in primary care by identifying potentially eligible participants, but this approach remains relatively unexplored in secondary care, and for stroke in particular. The REstart or STop Antithrombotics Randomised Trial (RESTART; ISRCTN71907627) is an ongoing RCT of secondary prevention after stroke due to intracerebral haemorrhage. Promoting Recruitment using Information Management Efficiently (PRIME) is a stepped-wedge cluster randomised trial of a complex intervention to help RESTART sites increase their recruitment and attain their own target numbers of participants. Seventy-two hospital sites that were located in England, Wales or Scotland and were active in RESTART in June 2015 opted into PRIME. Sites were randomly allocated (using a computer-generated block randomisation algorithm, stratified by hospital location in Scotland vs. England/Wales) to one of 12 months in which the intervention would be delivered. All sites began in the control state. The intervention was delivered by a recruitment co-ordinator via a teleconference with each site. The intervention involved discussing recruitment strategies, providing software for each site to extract from their own stroke audit data lists of patients who were potentially eligible for RESTART, and a second teleconference to review progress 6 months later. The recruitment co-ordinator was blinded to the timing of the intervention until 2 months before it was due at a site. Staff at RESTART sites were blinded to the nature and timing of the intervention. The primary outcome is the total number of patients randomised into RESTART per month per site and will be analysed in a negative binomial

  3. Ion Colliders

    CERN Document Server

    Fischer, W

    2014-01-01

    High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

  4. Failure Recovery via RESTART: Wallclock Models

    DEFF Research Database (Denmark)

    Asmussen, Søren; Rønn-Nielsen, Anders

    A task such as the execution of a computer program or the transfer of a file on a communications link may fail and then needs to be restarted. Let the ideal task time be a constant $\\ell$ and the actual task time $X$, a random variable. Tail asymptotics for $\\mathbb{P}(X>x)$ is given under three...... are presented for $X$ to be finite a.s. The results complement those of Asmussen, Fiorini, Lipsky, Rolski & Sheahan [Math. Oper. Res. 33, 932--944, 2008] who took $r(t)\\equiv 1$ and assumed the failure rate to be a function of the time elapsed since the last restart rather than wallclock time....

  5. Restart of the LHC in 2009

    CERN Multimedia

    Corinne Pralavorio

    The restart of the LHC during the summer 2009 has been confirmed today, the 5 December. An updated report on the incident which damaged sector 3-4 has just been published. It gives details on the damage caused by the incident and explains the ongoing repairs and the new systems being put into place to reinforce the safety of the machine. Click here to see the report.

  6. Waxy crude oil flow restart ability

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, Andre Gaona; Varges, Priscilla Ribeiro; Mendes, Paulo Roberto de Souza [Dept. of Mechanical Engineering. Pontificia Universidade Catolica do Rio de Janeiro, RJ (Brazil)], e-mails: prvarges@puc-rio.br, pmendes@puc-rio.br; Ziglio, Claudio [PETROBRAS S.A, R.J., Rio de Janeiro, RJ (Brazil)], e-mail: ziglio@petrobras.com.br

    2010-07-01

    Under the hot reservoir conditions, waxy crudes behave like Newtonian fluids but once they experience very cold temperatures on the sea floor, the heavy paraffin's begin to precipitate from the solution impacting non- Newtonian flow behavior to the crude (Chang 2000, Lee 2009, Davidson 2004) and begin to deposit on the pipe wall leave blocked of pipeline. This gel cannot be broken with the original steady state flow operating pressure applied before gelation (Chang 1998). Restarting waxy crude oil flows in pipelines is a difficult issue because of the complex rheological behavior of the gelled oil. Indeed, below the WAT, the gelled oil exhibits viscoplastic, thixotropic, temperature-dependent, and compressible properties due to the interlocking gel-like structure formed by the crystallized paraffin compounds and the thermal shrinkage of the oil. The main objective of this work is to determine the minimal pressure to restart the flow, and the relationship between the fluid rheology , pipe geometry and the restart pressure of the flow. Experiments will be performed to investigate the displacement of carbopol aqueous solutions (viscoplastic fluid without thixotropic effects) by Newtonian oil flowing through a strait pipe to validate the experimental apparatus. Therefore, tests will be made with different fluids, like Laponite and waxy crude oils. (author)

  7. Hitting times for random walks with restarts

    CERN Document Server

    Janson, Svante

    2010-01-01

    The time it takes a random walker in a lattice to reach the origin from another vertex $x$, has infinite mean. If the walker can restart the walk at $x$ at will, then the minimum expected hitting time $T(x,0)$ (minimized over restarting strategies) is finite; it was called the ``grade'' of $x$ by Dumitriu, Tetali and Winkler. They showed that, in a more general setting, the grade (a variant of the ``Gittins index'') plays a crucial role in control problems involving several Markov chains. Here we establish several conjectures of Dumitriu et al on the asymptotics of the grade in Euclidean lattices. In particular, we show that in the planar square lattice, $T(x,0)$ is asymptotic to $2|x|^2\\log|x|$ as $|x| \\to \\infty$. The proof hinges on the local variance of the potential kernel $h$ being almost constant on the level sets of $h$. We also show how the same method yields precise second order asymptotics for hitting times of a random walk (without restarts) in a lattice disk.

  8. Pervasive Restart In MOOSE-based Applications

    Energy Technology Data Exchange (ETDEWEB)

    Derek Gaston; Cody Permann; David Andrs; John Peterson; Andrew Slaughter; Jason Miller

    2014-01-01

    Multiphysics applications are inherently complicated. Solving for multiple, interacting physical phenomena involves the solution of multiple equations, and each equation has its own data dependencies. Feeding the correct data to these equations at exactly the right time requires extensive effort in software design. In an ideal world, multiphysics applications always run to completion and produce correct answers. Unfortunately, in reality, there can be many reasons why a simulation might fail: power outage, system failure, exceeding a runtime allotment on a supercomputer, failure of the solver to converge, etc. A failure after many hours spent computing can be a significant setback for a project. Therefore, the ability to “continue” a solve from the point of failure, rather than starting again from scratch, is an essential component of any high-quality simulation tool. This process of “continuation” is commonly termed “restart” in the computational community. While the concept of restarting an application sounds ideal, the aforementioned complexities and data dependencies present in multiphysics applications make its implementation decidedly non-trivial. A running multiphysics calculation accumulates an enormous amount of “state”: current time, solution history, material properties, status of mechanical contact, etc. This “state” data comes in many different forms, including scalar, tensor, vector, and arbitrary, application-specific data types. To be able to restart an application, you must be able to both store and retrieve this data, effectively recreating the state of the application before the failure. When utilizing the Multiphysics Object Oriented Simulation Environment (MOOSE) framework developed at Idaho National Laboratory, this state data is stored both internally within the framework itself (such as solution vectors and the current time) and within the applications that use the framework. In order to implement restart in MOOSE

  9. Restarted FOM Augmented with Ritz Vectors for Shifted Linear Systems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The restarted FOM method presented by Simoncini [7] according to the natural collinearity of all residuals is an efficient method for solving shifted systems, which generates the same Krylov subspace when the shifts are handled simultaneously. However, restarting slows down the convergence. We present a practical method for solving the shifted systems by adding some Ritz vectors into the Krylov subspace to form an augmented Krylov subspace.Numerical experiments illustrate that the augmented FOM approach (restarted version) can converge more quickly than the restarted FOM method.

  10. LHC Report: Rocky re-start

    CERN Multimedia

    Barbara Holzer for the LHC Team

    2012-01-01

    A rocky re-start with beam followed a successful machine development period and the first technical stop of 2012. Today, Friday 11 May, the machine began running again with 1380 bunches.   A short, two-day machine development period was successfully completed on 21-22 April. It focused on topics relevant for the 2012 physics beam operation. This was then followed by a five-day technical stop, the first of the year. The technical stop finished on time on Friday 26 April. The re-start with beam was somewhat tortuous and hampered by an unlucky succession of technical faults leading to extended periods of downtime. The planned intensity increase was put on hold for three days with the machine operating with 1092 bunches and a moderate bunch intensity of 1.3x1011 protons. This delivered a reasonable peak luminosity of 3.6x1033 cm-2s-1 to ATLAS and CMS. Higher than usual beam losses were observed in the ramp and squeeze, and time was required to investigate the causes and to implement mitigati...

  11. Re-starting an Arnoldi iteration

    Energy Technology Data Exchange (ETDEWEB)

    Lehoucq, R.B. [Argonne National Lab., IL (United States)

    1996-12-31

    The Arnoldi iteration is an efficient procedure for approximating a subset of the eigensystem of a large sparse n x n matrix A. The iteration produces a partial orthogonal reduction of A into an upper Hessenberg matrix H{sub m} of order m. The eigenvalues of this small matrix H{sub m} are used to approximate a subset of the eigenvalues of the large matrix A. The eigenvalues of H{sub m} improve as estimates to those of A as m increases. Unfortunately, so does the cost and storage of the reduction. The idea of re-starting the Arnoldi iteration is motivated by the prohibitive cost associated with building a large factorization.

  12. ALICE & LHCb: refinements for the restart

    CERN Multimedia

    2009-01-01

    Following the previous issue, the Bulletin continues its series to find out what the six LHC experiments have been up to since last September, and how they are preparing for the restart. Previously we looked at CMS and ATLAS; this issue we will round up the past 10 months of activity at ALICE and LHCb. LHCb The cavern of the LHCb experiment. This year has given LHCb the chance to install the 5th and final plane of muon chambers, which will improve the triggering at nominal luminosity. This is the final piece of the experiment to be installed. "Now the detector looks exactly as it does in the technical design report," confirms Andrei Golutvin, LHCb Spokesperson. "We also took advantage of this shutdown to make several improvements. For example, we modified the high voltage system of the electromagnetic calorimeter to reduce noise further to a negligible level. We also took some measures to improve ...

  13. Preparing for the re-start

    CERN Multimedia

    2009-01-01

    The end of a Council week is a good opportunity to bring you up to date with the status of the LHC, and I’m pleased to say that we had a good deal of positive news to report to the delegations today. The bottom line is that we remain on course to restart the LHC safely this year, albeit currently about 2-3 weeks later than we’d hoped at Chamonix. This Council week has seen many important developments for our future. I am particularly pleased that Council approved the Medium Term Plan and budget for 2010 as presented by the management. This is a strong vote of confidence in all of you. The President of Council is reporting on Council business in this issue of the Bulletin, so I will focus on the status of the LHC. A tremendous amount of work has been done to understand fully the splices in the LHC’s superconducting cable and copper stabilizers. One of these splices was the root cause of the incident last September that brought ...

  14. A Restarted Conjugate Gradient Method for Ill-posed Problems

    Institute of Scientific and Technical Information of China (English)

    Yan-fei Wang

    2003-01-01

    This paper presents a restarted conjugate gradient iterative algorithm for solving ill-posed problems.The damped Morozov's discrepancy principle is used as a stopping rule. Numerical experiments are given to illustrate the efficiency of the method.

  15. LHC Availability 2016: Restart to Technical Stop 1

    CERN Document Server

    Todd, Benjamin; Apollonio, Andrea; CERN. Geneva. ATS Department

    2016-01-01

    This document summarises the LHC machine availability for the period of Restart to Technical Stop 1 (TS1) in 2016. This period was dedicated to restart of the LHC for proton physics with a bunch spacing of 25ns. This note has been produced and ratified by the LHC Availability Working Group which has complied fault information for the period in question using the Accelerator Fault Tracker.

  16. A simple strategy for varying the restart parameter in GMRES(m)

    Energy Technology Data Exchange (ETDEWEB)

    Baker, A H; Jessup, E R; Kolev, T V

    2007-10-02

    When solving a system of linear equations with the restarted GMRES method, a fixed restart parameter is typically chosen. We present numerical experiments that demonstrate the beneficial effects of changing the value of the restart parameter in each restart cycle on the total time to solution. We propose a simple strategy for varying the restart parameter and provide some heuristic explanations for its effectiveness based on analysis of the symmetric case.

  17. The LHC restart in one minute

    CERN Multimedia

    2016-01-01

    On Friday March 25 2016, the Large Hadron Collider (LHC) got its first proton beam of the year. In just over 1 minute this time-lapse provides a quick overview to some of the important milestones that preceded proton beam injection this year, against a background of activities over the last few days in the CERN Control Centre (CCC), the place where the CERN accelerator chain is operated and controlled. Read more: http://cern.ch/go/Z9cz Music From FruityAudio, entitled "New Groove". - Producer - Audiovisual production service Paola Catapano - Director - Julien Ordan - Camera - Julien Ordan Maximilien Brice - Graphics \\ Animations - Arzur Catel Torres - Infography - Daniel Dominguez Noemi Caraban - Music - FruityAudio - New groove Category Film & Animation License Standard YouTube License

  18. Restarting TMI unit one: social and psychological impacts

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, J.; Soderstrom, J.; Bolin, R.; Copenhaver, E.; Carnes, S.

    1983-12-01

    A technical background is provided for preparing an environmental assessment of the social and psychological impacts of restarting the undamaged reactor at Three Mile Island (TMI). Its purpose is to define the factors that may cause impacts, to define what those impacts might be, and to make a preliminary assessment of how impacts could be mitigated. It does not attempt to predict or project the magnitude of impacts. Four major research activities were undertaken: a literature review, focus-group discussions, community profiling, and community surveys. As much as possible, impacts of the accident at Unit 2 were differentiated from the possible impacts of restarting Unit 1. It is concluded that restart will generate social conflict in the TMI vicinity which could lead to adverse effects. Furthermore, between 30 and 50 percent of the population possess characteristics which are associated with vulnerability to experiencing negative impacts. Adverse effects, however, can be reduced with a community-based mitigation strategy.

  19. Future colliders at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Tsesmelis, E. [CERN, Geneva (Switzerland)

    2010-07-15

    Following an outline of the Large Hadron Collider, this paper will analyze CERN's scientific plans for high-energy colliders for the years to come. The immediate plans include the upgrades to the Large Hadron Collider and its injectors. This may be followed by a linear electron-positron collider, the Compact Linear Collider. This paper describes the design of these future colliders at CERN, all of which have a unique value to add to experimental particle physics. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  20. Whither colliders after the Large Hadron Collider?

    Indian Academy of Sciences (India)

    Rolf-Dieter Heuer

    2012-11-01

    This paper presents options for high-energy colliders at the energy frontier for the years to come. The immediate plans include the exploitation of the LHC at its design luminosity and energy as well as upgrades to the LHC (luminosity and energy) and to its injectors. This may be complemented by a linear electron–positron collider, based on the technology being developed by the Compact Linear Collider and by the International Linear Collider, by a high-energy electron– proton machine, the LHeC, and/or by a muon collider. This contribution describes the various future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining the key messages for the way forward.

  1. FINAL REPORT UFP RESTART AND SPARGER TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, H; Michael Restivo, M

    2004-11-30

    Following a Design Basis Event (DBE), potential plugging of the PJM systems is highly probable after air compressors and/or electric power become unavailable for up to 100 hrs. Under such conditions, the rheologically bounding yield stress of the pretreated sludge simulant could reach 300-625 Pa. (Defined in WTP-RPP-100, Rev. 0, Sec. 6.1. [1] and WTP-RPP-98, Rev. 0, Secs. 5.1 and 5.2 [2].) The tests covered under this report are conservative since this range of bounding yield stress is based on the settled solids component in the tank. Also, note that CCN 065607 states that the design basis is 70 Pa for 'gelled material' over the entire tank. Three issues must be addressed by these tests: (1) Determine the required pressure and air flow to overcome the plugged sparger tube resistance following a DBE event. (2) Can the UFP PJMs be restarted with or without assistance from air spargers? (3) Show that solids can be mixed by air spargers following a DBE to allow generated hydrogen gas to rise and be vented to the vessel head space. This is to limit hydrogen concentrations below LFL level. In the first test, a full-scale sparger was simulated by a 2-inch dia. Schedule 160 pipe, installed in an 18-inch diameter plastic tank, 37-foot high (full scale height), 6-inch from the bottom. The bottom 5-ft. lower section was clear to facilitate visual observations. Two simulants were used: a 120 Pa Laponite solution and a 30 Pa/30 cP kaolin:bentonite clay mixture, which filled the tank to the 32-foot level. The first test with 120 Pa Laponite demonstrated breakthrough at an air pressure of 14.6 psig. The second test with the clay simulant resulted in breakthrough at 16.7 psig. Given the specific gravities of these simulants, the breakthrough pressures are very close to the hydrostatic pressures corresponding to the simulant elevations inside the sparger. The CRV test stand at the Engineering Development Laboratory, SRNL, was used to simulate the UFP at 1/4-scale, where

  2. Restarting Automata with Auxiliary Symbols and Small Lookahead

    DEFF Research Database (Denmark)

    Schluter, Natalie Elaine

    2012-01-01

    We present a study on lookahead hierarchies for restarting automata with auxiliary symbols and small lookahead. In particular, we show that there are just two different classes of languages recognised by RRWW automata, through the restriction of lookahead size. We also show that the respective...

  3. 40 CFR 86.236-94 - Engine starting and restarting.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Engine starting and restarting. 86.236-94 Section 86.236-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.236-94 Engine starting...

  4. User Process Checkpoint/Restart. Revision 1.1.

    Science.gov (United States)

    2007-11-02

    This document describes the design of the Tera user process checkpoint facility. Checkpoint is a means for saving the state of an executing process...or group of processes and restarting them later on demand. The motivation for providing checkpoint on the Tera is to allow long running computationally

  5. Restart plan for the prototype vertical denitration calciner

    Energy Technology Data Exchange (ETDEWEB)

    SUTTER, C.S.

    1999-09-01

    Testing activities on the Prototype Vertical Denitration Calciner at PFP were suspended in January 1997 due to the hold on fissile material handling in the facility. The Restart Plan will govern the transition of the test program from the completion of the activity based startup review; through equipment checkout and surrogate material runs; to resumption of the testing program and transition to unrestricted testing.

  6. Photon collider Higgs factories

    CERN Document Server

    Telnov, V I

    2014-01-01

    The discovery of the Higgs boson (and still nothing else) have triggered appearance of many proposals of Higgs factories for precision measurement of the Higgs properties. Among them there are several projects of photon colliders (PC) without e+e- in addition to PLC based on e+e- linear colliders ILC and CLIC. In this paper, following a brief discussion of Higgs factories physics program I give an overview of photon colliders based on linear colliders ILC and CLIC, and of the recently proposed photon-collider Higgs factories with no e+e- collision option based on recirculation linacs in ring tunnels.

  7. Hadron Colliders and Hadron Collider Physics Symposium

    Directory of Open Access Journals (Sweden)

    Denisov D.

    2013-05-01

    Full Text Available This article summarizes main developments of the hadron colliders and physics results obtained since their inception around forty years ago. The increase in the collision energy of over two orders of magnitude and even larger increases in luminosity provided experiments with unique data samples. Developments of full acceptance detectors, particle identification and analysis methods provided fundamental discoveries and ultra-precise measurements which culminated in the completion and in depth verification of the Standard Model. Hadron Collider Physics symposium provided opportunities for those working at hadron colliders to share results of their research since 1979 and helped greatly to develop the field of particle physics.

  8. The development of colliders

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, A.M.

    1997-03-01

    During the period of the 50`s and the 60`s colliders were developed. Prior to that time there were no colliders, and by 1965 a number of small devices had worked, good understanding had been achieved, and one could speculate, as Gersh Budker did, that in a few years 20% of high energy physics would come from colliders. His estimate was an under-estimate, for now essentially all of high energy physics comes from colliders. The author presents a brief review of that history: sketching the development of the concepts, the experiments, and the technological advances which made it all possible.

  9. Muon collider design

    Science.gov (United States)

    Palmer, R.; Sessler, A.; Skrinsky, A.; Tollestrup, A.; Baltz, A.; Caspi, S.; P., Chen; W-H., Cheng; Y., Cho; Cline, D.; Courant, E.; Fernow, R.; Gallardo, J.; Garren, A.; Gordon, H.; Green, M.; Gupta, R.; Hershcovitch, A.; Johnstone, C.; Kahn, S.; Kirk, H.; Kycia, T.; Y., Lee; Lissauer, D.; Luccio, A.; McInturff, A.; Mills, F.; Mokhov, N.; Morgan, G.; Neuffer, D.; K-Y., Ng; Noble, R.; Norem, J.; Norum, B.; Oide, K.; Parsa, Z.; Polychronakos, V.; Popovic, M.; Rehak, P.; Roser, T.; Rossmanith, R.; Scanlan, R.; Schachinger, L.; Silvestrov, G.; Stumer, I.; Summers, D.; Syphers, M.; Takahashi, H.; Torun, Y.; Trbojevic, D.; Turner, W.; van Ginneken, A.; Vsevolozhskaya, T.; Weggel, R.; Willen, E.; Willis, W.; Winn, D.; Wurtele, J.; Zhao, Y.

    1996-11-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity \\mu^+ \\mu^- colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Detector background, polarization, and nonstandard operating conditions are discussed.

  10. LHC Availability 2017: Restart to Technical Stop 1

    CERN Document Server

    Todd, Benjamin; Apollonio, Andrea

    2017-01-01

    This document summarises the LHC machine availability for the period of Restart to Technical Stop 1 (TS1) in 2017. This period consisted of recommissioning the LHC following the Extended year End Technical Stop (EYETS 2016-17), and proton physics with a bunch spacing of 25ns. This note has been produced and ratified by the Availability Working Group which has complied fault information for the period in question using the Accelerator Fault Tracker.

  11. Applications of implicit restarting in optimization and control Dan Sorensen

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, D. [Rice Univ., Houston, TX (United States)

    1996-12-31

    Implicit restarting is a technique for combining the implicitly shifted QR mechanism with a k-step Arnoldi or Lanczos factorization to obtain a truncated form of the implicitly shifted QR-iteration suitable for large scale eigenvalue problems. The software package ARPACK based upon this technique has been successfully used to solve large scale symmetric and nonsymmetric (generalized) eigenvalue problems arising from a variety of applications.

  12. RELAP5-3D Restart and Backup Verification Testing

    Energy Technology Data Exchange (ETDEWEB)

    Dr. George L Mesina

    2013-09-01

    Existing testing methodology for RELAP5-3D employs a set of test cases collected over two decades to test a variety of code features and run on a Linux or Windows platform. However, this set has numerous deficiencies in terms of code coverage, detail of comparison, running time, and testing fidelity of RELAP5-3D restart and backup capabilities. The test suite covers less than three quarters of the lines of code in the relap directory and just over half those in the environmental library. Even in terms of code features, many are not covered. Moreover, the test set runs many problems long past the point necessary to test the relevant features. It requires standard problems to run to completion. This is unnecessary for features can be tested in a short-running problem. For example, many trips and controls can be tested in the first few time steps, as can a number of fluid flow options. The testing system is also inaccurate. For the past decade, the diffem script has been the primary tool for checking that printouts from two different RELAP5-3D executables agree. This tool compares two output files to verify that all characters are the same except for those relating to date, time and a few other excluded items. The variable values printed on the output file are accurate to no more than eight decimal places. Therefore, calculations with errors in decimal places beyond those printed remain undetected. Finally, fidelity of restart is not tested except in the PVM sub-suite and backup is not specifically tested at all. When a restart is made from any midway point of the base-case transient, the restart must produce the same values. When a backup condition occurs, the code repeats advancements with the same time step. A perfect backup can be tested by forcing RELAP5 to perform a backup by falsely setting a backup condition flag at a user-specified-time. Comparison of the calculations of that run and those produced by the same input w/o the spurious condition should be

  13. Towards future circular colliders

    Science.gov (United States)

    Benedikt, Michael; Zimmermann, Frank

    2016-09-01

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) presently provides proton-proton collisions at a center-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics program will extend through the second half of the 2030's. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ˜100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCCee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3 S n superconductor, for the FCC-hh hadron collider, and a highly-efficient superconducting radiofrequency system for the FCC-ee lepton collider. Following the FCC concept, the Institute of High Energy Physics (IHEP) in Beijing has initiated a parallel design study for an e + e - Higgs factory in China (CEPC), which is to be succeeded by a high-energy hadron collider (SPPC). At present a tunnel circumference of 54 km and a hadron collider c.m. energy of about 70 TeV are being considered. After a brief look at the LHC, this article reports the motivation and the present status of the FCC study, some of the primary design challenges and R&D subjects, as well as the emerging global collaboration.

  14. Restart-Based Genetic Algorithm for the Quadratic Assignment Problem

    Science.gov (United States)

    Misevicius, Alfonsas

    The power of genetic algorithms (GAs) has been demonstrated for various domains of the computer science, including combinatorial optimization. In this paper, we propose a new conceptual modification of the genetic algorithm entitled a "restart-based genetic algorithm" (RGA). An effective implementation of RGA for a well-known combinatorial optimization problem, the quadratic assignment problem (QAP), is discussed. The results obtained from the computational experiments on the QAP instances from the publicly available library QAPLIB show excellent performance of RGA. This is especially true for the real-life like QAPs.

  15. An Efficient Variant of the Restarted Shifted GMRES Method for Solving Shifted Linear Systems

    Institute of Scientific and Technical Information of China (English)

    Akira IMAKURA; Tomohiro SOGABE; Shaoliang ZHANG

    2013-01-01

    We investigate the restart of the Restarted Shifted GMRES method for solving shifted linear systems.Recently the variant of the GMRES(m) method with the unfixed update has been proposed to improve the convergence of the GMRES(m) method for solving linear systems,and shown to have an efficient convergence property.In this paper,by applying the unfixed update to the Restarted Shifted GMRES method,we propose a variant of the Restarted Shifted GMRES method.We show a potentiality for efficient convergence within the variant by some numerical results.

  16. Linear collider: a preview

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, H.

    1981-11-01

    Since no linear colliders have been built yet it is difficult to know at what energy the linear cost scaling of linear colliders drops below the quadratic scaling of storage rings. There is, however, no doubt that a linear collider facility for a center of mass energy above say 500 GeV is significantly cheaper than an equivalent storage ring. In order to make the linear collider principle feasible at very high energies a number of problems have to be solved. There are two kinds of problems: one which is related to the feasibility of the principle and the other kind of problems is associated with minimizing the cost of constructing and operating such a facility. This lecture series describes the problems and possible solutions. Since the real test of a principle requires the construction of a prototype I will in the last chapter describe the SLC project at the Stanford Linear Accelerator Center.

  17. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2015-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The interna...

  18. Towards Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    The Large Hadron Collider (LHC) at CERN presently provides proton-proton collisions at a centre-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics programme will extend through the second half of the 2030’s. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ∼100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCC-ee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on $Nb_3Sn$ superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton c...

  19. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2015-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detector, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The internat...

  20. Markov Renewal Methods in Restart Problems in Complex Systems

    DEFF Research Database (Denmark)

    Asmussen, Søren; Lipsky, Lester; Thompson, Stephen

    A task with ideal execution time L such as the execution of a computer program or the transmission of a file on a data link may fail, and the task then needs to be restarted. The task is handled by a complex system with features similar to the ones in classical reliability: failures may...... be mitigated by using server redundancy in parallel or k-out-of-n arrangements, standbys may be cold or warm, one or more repairmen may take care of failed components, etc. The total task time X (including restarts and pauses in failed states) is investigated with particular emphasis on the tail P(X > x......). A general alternating Markov renewal model is proposed and an asymptotic exponential form P(X > x) ∼ Ce−γx identified for the case of a deterministic task time L ≡ `. The rate γ is given by equating the spectral radius of a certain matrix to 1, and the asymptotic form of γ = γ(`) as ` → ∞ is derived...

  1. Keeping checkpoint/restart viable for exascale systems.

    Energy Technology Data Exchange (ETDEWEB)

    Riesen, Rolf E.; Bridges, Patrick G. (IBM Research, Ireland, Mulhuddart, Dublin); Stearley, Jon R.; Laros, James H., III; Oldfield, Ron A.; Arnold, Dorian (University of New Mexico, Albuquerque, NM); Pedretti, Kevin Thomas Tauke; Ferreira, Kurt Brian; Brightwell, Ronald Brian

    2011-09-01

    Next-generation exascale systems, those capable of performing a quintillion (10{sup 18}) operations per second, are expected to be delivered in the next 8-10 years. These systems, which will be 1,000 times faster than current systems, will be of unprecedented scale. As these systems continue to grow in size, faults will become increasingly common, even over the course of small calculations. Therefore, issues such as fault tolerance and reliability will limit application scalability. Current techniques to ensure progress across faults like checkpoint/restart, the dominant fault tolerance mechanism for the last 25 years, are increasingly problematic at the scales of future systems due to their excessive overheads. In this work, we evaluate a number of techniques to decrease the overhead of checkpoint/restart and keep this method viable for future exascale systems. More specifically, this work evaluates state-machine replication to dramatically increase the checkpoint interval (the time between successive checkpoint) and hash-based, probabilistic incremental checkpointing using graphics processing units to decrease the checkpoint commit time (the time to save one checkpoint). Using a combination of empirical analysis, modeling, and simulation, we study the costs and benefits of these approaches on a wide range of parameters. These results, which cover of number of high-performance computing capability workloads, different failure distributions, hardware mean time to failures, and I/O bandwidths, show the potential benefits of these techniques for meeting the reliability demands of future exascale platforms.

  2. Inner Random Restart Genetic Algorithm for Practical Delivery Schedule Optimization

    Science.gov (United States)

    Sakurai, Yoshitaka; Takada, Kouhei; Onoyama, Takashi; Tsukamoto, Natsuki; Tsuruta, Setsuo

    A delivery route optimization that improves the efficiency of real time delivery or a distribution network requires solving several tens to hundreds but less than 2 thousands cities Traveling Salesman Problems (TSP) within interactive response time (less than about 3 second), with expert-level accuracy (less than about 3% of error rate). Further, to make things more difficult, the optimization is subjects to special requirements or preferences of each various delivery sites, persons, or societies. To meet these requirements, an Inner Random Restart Genetic Algorithm (Irr-GA) is proposed and developed. This method combines meta-heuristics such as random restart and GA having different types of simple heuristics. Such simple heuristics are 2-opt and NI (Nearest Insertion) methods, each applied for gene operations. The proposed method is hierarchical structured, integrating meta-heuristics and heuristics both of which are multiple but simple. This method is elaborated so that field experts as well as field engineers can easily understand to make the solution or method easily customized and extended according to customers' needs or taste. Comparison based on the experimental results and consideration proved that the method meets the above requirements more than other methods judging from not only optimality but also simplicity, flexibility, and expandability in order for this method to be practically used.

  3. Berkeley lab checkpoint/restart (BLCR) for Linux clusters

    Science.gov (United States)

    Hargrove, Paul H.; Duell, Jason C.

    2006-09-01

    This article describes the motivation, design and implementation of Berkeley Lab Checkpoint/Restart (BLCR), a system-level checkpoint/restart implementation for Linux clusters that targets the space of typical High Performance Computing applications, including MPI. Application-level solutions, including both checkpointing and fault-tolerant algorithms, are recognized as more time and space efficient than system-level checkpoints, which cannot make use of any application-specific knowledge. However, system-level checkpointing allows for preemption, making it suitable for responding to ''fault precursors'' (for instance, elevated error rates from ECC memory or network CRCs, or elevated temperature from sensors). Preemption can also increase the efficiency of batch scheduling; for instance reducing idle cycles (by allowing for shutdown without any queue draining period or reallocation of resources to eliminate idle nodes when better fitting jobs are queued), and reducing the average queued time (by limiting large jobs to running during off-peak hours, without the need to limit the length of such jobs). Each of these potential uses makes BLCR a valuable tool for efficient resource management in Linux clusters.

  4. Restart of K-Reactor, Savannah River Site: Safety evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    1991-04-01

    This Safety Evaluation Report (SER) focuses on those issues required to support the restart of the K-Reactor at the Savannah River Plant. This SER provides the safety criteria for restart and documents the results of the staff reviews of the DOE and operating contractor activities to meet these criteria. To develop the restart criteria for the issues discussed in this SER, the Savannah River Restart Office and Savannah River Special Projects Office staffs relied, when possible, on commercial industry codes and standards and on NRC requirements and guidelines for the commercial nuclear industry. However, because of the age and uniqueness of the Savannah River reactors, criteria for the commercial plants were not always applicable. In these cases, alternate criteria were developed. The restart criteria applicable to each of the issues are identified in the safety evaluations for each issue. The restart criteria identified in this report are intended to apply only to restart of the Savannah River reactors. Following the development of the acceptance criteria, the DOE staff and their support contractors evaluated the results of the DOE and operating contractor (WSRC) activities to meet these criteria. The results of those evaluations are documented in this report. Deviations or failures to meet the requirements are either justified in the report or carried as open or confirmatory items to be completed and evaluated in supplements to this report before restart. 62 refs., 1 fig.

  5. The International Linear Collider

    CERN Document Server

    Barish, Barry

    2013-01-01

    In this article, we describe the key features of the recently completed technical design for the International Linear Collider (ILC), a 200-500 GeV linear electron-positron collider (expandable to 1 TeV) that is based on 1.3 GHz superconducting radio-frequency (SCRF) technology. The machine parameters and detector characteristics have been chosen to complement the Large Hadron Collider physics, including the discovery of the Higgs boson, and to further exploit this new particle physics energy frontier with a precision instrument. The linear collider design is the result of nearly twenty years of R&D, resulting in a mature conceptual design for the ILC project that reflects an international consensus. We summarize the physics goals and capability of the ILC, the enabling R&D and resulting accelerator design, as well as the concepts for two complementary detectors. The ILC is technically ready to be proposed and built as a next generation lepton collider, perhaps to be built in stages beginning as a Hig...

  6. The development of colliders

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, A.M.

    1993-02-01

    Don Kerst, Gersh Budker, and Bruno Touschek were the individuals, and the motivating force, which brought about the development of colliders, while the laboratories at which it happened were Stanford, MURA, the Cambridge Electron Accelerator, Orsay, Frascati, CERN, and Novosibirsk. These laboratories supported, during many years, this rather speculative activity. Of course, many hundreds of physicists contributed to the development of colliders but the men who started it, set it in the right direction, and forcefully made it happen, were Don, Gersh, and Bruno. Don was instrumental in the development of proton-proton colliders, while Bruno and Gersh spearheaded the development of electron-positron colliders. In this brief review of the history, I will sketch the development of the concepts, the experiments, and the technological developments which made possible the development of colliders. It may look as if the emphasis is on theoretical concepts, but that is really not the case, for in this field -- the physics of beams -- the theory and experiment go hand in hand; theoretical understanding and advances are almost always motivated by the need to explain experimental results or the desire to construct better experimental devices.

  7. COLLIDE Pro Helvetia Award

    CERN Document Server

    2016-01-01

    The COLLIDE Pro Helvetia Award is run in partnership with Pro Helvetia, giving the opportunity to Swiss artists to do research at CERN for three months.   From left to right: Laura Perrenoud, Marc Dubois and Simon de Diesbach. The photo shows their VR Project, +2199. Fragment.In are the winning artists of COLLIDE Pro Helvetia. They came to CERN for two months in 2015, and will now continue their last month in the laboratory. Fragment.In is a Swiss based interaction design studio. They create innovative projects, interactive installations, video and game design. Read more about COLLIDE here.

  8. Stop and Restart Effects on Modern Vehicle Starting System Components

    Energy Technology Data Exchange (ETDEWEB)

    Windover, Paul R. [Argonne National Lab. (ANL), Argonne, IL (United States); Owens, Russell J. [Argonne National Lab. (ANL), Argonne, IL (United States); Levinson, Terry M. [Argonne National Lab. (ANL), Argonne, IL (United States); Laughlin, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Gaines, Linda [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-01

    Many drivers of personal and commercial vehicles believe that turning the vehicle off and on frequently instead of idling will cause premature wear of the starter system (starter motor and starter battery). As a result, they are concerned that the replacement cost of the starter motor and/or battery due to increased manual engine cycling would be more than the cumulative cost of the fuel saved by not idling unnecessarily. A number of variables play a role in addressing this complex concern, including the number of starting cycles per day, the time between starting cycles, the intended design life of the starting system, the amount of fuel used to restart an engine, and the cumulative cost of the saved fuel. Qualitative and quantitative information from a variety of sources was used to develop a life-cycle economic model to evaluate the cost and quantify the realistic factors that are related to the permissible frequency of starter motor cycles for the average vehicle to economically minimize engine idle time. Annual cost savings can be calculated depending on shutdown duration and the number of shutdown cycles per day. Analysis shows that cost savings are realized by eliminating idling exceeding one minute by shutting down the engine and restarting it. For a typical motorist, the damage to starting system components resulting from additional daily start cycles will be negligible. Overall, it was found that starter life is mostly dependent on the total number of start cycles, while battery life is more dependent on ensuring a full charge between start events.

  9. Collide@CERN Geneva

    CERN Document Server

    CERN. Geneva; Kieffer, Robert; Blas Temino, Diego; Bertolucci, Sergio; Mr. Decelière, Rudy; Mr. Hänni, Vincent

    2014-01-01

    CERN, the Republic and Canton of Geneva, and the City of Geneva are delighted to invite you to “Collide@CERN Geneva Music”. Come to the public lecture about collisions between music and particle physics by the third winners of Collide@CERN Geneva, Vincent Hänni & Rudy Decelière, and their scientific inspiration partners, Diego Blas and Robert Kieffer. The event marks the beginning of their residency at CERN, and will be held at the CERN Globe of Science and Innovation on 16 October 2014 at 19.00. Doors will open at 18.30.

  10. Muon collider design

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, R. [Brookhaven National Lab., Upton, NY (United States)]|[Stanford Linear Accelerator Center, Menlo Park, CA (United States); Sessler, A. [Lawrence Berkeley National Lab., CA (United States); Skrinsky, A. [AN SSSR, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki

    1996-03-01

    The possibility of muon colliders was introduced by Skrinsky et al., Neuffer, and others. More recently, several workshops and collaboration meetings have greatly increased the level of discussion. In this paper we present scenarios for 4 TeV and 0.5 TeV colliders based on an optimally designed proton source, and for a lower luminosity 0.5 TeV demonstration based on an upgraded version of the AGS. It is assumed that a demonstration version based on upgrades of the FERMILAB machines would also be possible. 53 refs., 25 figs., 8 tabs.

  11. Collider signatures of hylogenesis

    Science.gov (United States)

    Demidov, S. V.; Gorbunov, D. S.; Kirpichnikov, D. V.

    2015-02-01

    We consider collider signatures of the hylogenesis—a variant of the antibaryonic dark matter model. We obtain bounds on the model parameters from results of the first LHC run. Also we suggest several new channels relevant for probing the antibaryonic dark matter at LHC.

  12. Collider signatures of Hylogenesis

    CERN Document Server

    Demidov, S V; Kirpichnikov, D V

    2014-01-01

    We consider collider signatures of the hylogenesis --- a variant of antibaryonic dark matter model. We obtain bounds on the model parameters from results of the first LHC run. Also we suggest several new channels relevant for probing the antibaryonic dark matter at LHC.

  13. The Large Hadron Collider

    CERN Multimedia

    't Hooft, Gerardus; Llewellyn Smith, Christopher Hubert; Brüning, Oliver Sim; Collier, Paul; Stapnes, Steinar; Ellis, Jonathan Richard; Braun-Munzinger, Peter; Stachel, Johanna; Lederman, Leon Max

    2007-01-01

    Several articles about the LHC: The Making of the standard model; high-energy colliders and the rise of the standard model; How the LHC came to be; Building a behemoth; Detector challenges at the LHC; Beyond the standard model with the LHC; The quest for the quark-gluon plasma; The God particle et al. (42 pages

  14. Hadron collider physics

    Energy Technology Data Exchange (ETDEWEB)

    Pondrom, L.

    1991-10-03

    An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs.

  15. The Large Hadron Collider

    CERN Multimedia

    Wright, Alison

    2007-01-01

    "We are on the threshold of a new era in particle-physics research. In 2008, the Large Hadron Collider (LHC) - the hightest-energy accelerator ever built - will come into operation at CERN, the European labortory that straddles the French-Swiss border near Geneva." (1/2 page)

  16. Toponium at hadronic colliders

    Energy Technology Data Exchange (ETDEWEB)

    Finjord, J. (Bern Univ. (Switzerland)); Girardi, G.; Sorba, P. (Grenoble-1 Univ., 74 - Annecy (France). Lab. de Physique des Particules); Mery, P. (European Organization for Nuclear Research, Geneva (Switzerland))

    1982-05-27

    We calculate hadronic toponium production by specific diagrams obeying colour conservation and charge conjugation. The resulting rates, though lower than those calculated using semi-local duality arguments are encouraging and may allow for toponium discovery at hadronic colliders currently in development.

  17. Tevatron's complex collider cousins

    CERN Multimedia

    Fischer, W

    2004-01-01

    Letter referring to Schwarzschild's story "Disappointing performance and tight budgets confront Fermilab with tough decisions" and contesting that the Tevatron is not the most complex accelerator operating. They use the examples of CERN's SPS collider, HERA at DESY and the RHIC at Brookhaven (1/4 page)

  18. When stars collide

    NARCIS (Netherlands)

    Glebbeek, E.; Pols, O.R.

    2007-01-01

    When two stars collide and merge they form a new star that can stand out against the background population in a star cluster as a blue straggler. In so called collision runaways many stars can merge and may form a very massive star that eventually forms an intermediate mass blackhole. We have perfor

  19. Introductory Lectures on Collider Physics

    Science.gov (United States)

    Tait, Tim M. P.; Wang, Lian-Tao

    2013-12-01

    These are elementary lectures about collider physics. They are aimed at graduate students who have some background in computing Feynman diagrams and the Standard Model, but assume no particular sophistication with the physics of high energy colliders.

  20. High luminosity muon collider design

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, R.; Gallardo, J.

    1996-10-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should be regarded as complementary. Parameters are given of 4 TeV high luminosity {mu}{sup +}{mu}{sup {minus}} collider, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders.

  1. Mental health effects of the Three Mile Island nuclear reactor restart

    Energy Technology Data Exchange (ETDEWEB)

    Dew, M.A.; Bromet, E.J.; Schulberg, H.C.; Dunn, L.O.; Parkinson, D.K.

    1987-08-01

    Controversy over potential mental health effects of the Three Mile Island Unit-1 restart led the authors to examine prospectively the pattern of psychiatric symptoms in a sample of Three Mile Island area mothers of young children. Symptom levels after restart were elevated over previous levels; a sizable subcohort of the sample reported relatively serious degrees of postrestart distress. History of diagnosable major depression and generalized anxiety following the Three Mile Island accident, plus symptoms and beliefs about personal risk prior to the restart, best predicted postrestart symptoms.

  2. The Large Hadron Collider

    CERN Document Server

    Juettner Fernandes, Bonnie

    2014-01-01

    What really happened during the Big Bang? Why did matter form? Why do particles have mass? To answer these questions, scientists and engineers have worked together to build the largest and most powerful particle accelerator in the world: the Large Hadron Collider. Includes glossary, websites, and bibliography for further reading. Perfect for STEM connections. Aligns to the Common Core State Standards for Language Arts. Teachers' Notes available online.

  3. Accelerators, Colliders, and Snakes

    Science.gov (United States)

    Courant, Ernest D.

    2003-12-01

    The author traces his involvement in the evolution of particle accelerators over the past 50 years. He participated in building the first billion-volt accelerator, the Brookhaven Cosmotron, which led to the introduction of the "strong-focusing" method that has in turn led to the very large accelerators and colliders of the present day. The problems of acceleration of spin-polarized protons are also addressed, with discussions of depolarizing resonances and "Siberian snakes" as a technique for mitigating these resonances.

  4. Why Large Hadron Collider?

    Indian Academy of Sciences (India)

    D P Roy

    2011-05-01

    I discuss LHC physics in the historical perspective of the progress in particle physics. After a recap of the Standard Model (SM) of particle physics, I discuss the high energy colliders leading up to LHC and their role in the discovery of these SM particles. Then I discuss the two main physics issues of LHC, i.e. Higgs mechanism and supersymmetry. I briefly touch upon Higgs and SUSY searches at LHC along with their cosmological implications.

  5. Optimal Rapid Restart of Heuristic Methods of NP Hard Problems

    Institute of Scientific and Technical Information of China (English)

    侯越先; 王芳

    2004-01-01

    Many heuristic search methods exhibit a remarkable variability in the time required to solve some particular problem instances. Their cost distributions are often heavy-tailed. It has been demonstrated that, in most cases, rapid restart (RR) method can prominently suppress the heavy-tailed nature of the instances and improve computation efficiency. However, it is usually time-consuming to check whether an algorithm on a specific instance is heavy-tailed or not. Moreover, if the heavy-tailed distribution is confirmed and the RR method is relevant, an optimal RR threshold should be chosen to facilitate the RR mechanism. In this paper, an approximate approach is proposed to quickly check whether an algorithm on a specific instance is heavy-tailed or not.The method is realized by means of calculating the maximal Lyapunov exponent of its generic running trace.Then a statistical formula to estimate the optimal RR threshold is educed. The method is based on common nonparametric estimation, e. g. , Kernel estimation. Two heuristic methods are selected to verify our method. The experimental results are consistent with the theoretical consideration perfectly.

  6. Latest news from the YETS: all restarting except the LHC

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    With the closure of the SPS at 3 p.m. on Friday, 19 February, maintenance work is now ongoing only at the LHC. All activities are on track for a smooth restart in a few weeks’ time.   At the LHC, all general maintenance activities are proceeding well and according to schedule. In particular, the electrical tests on the general emergency stops have been completed, while the cooling and ventilation maintenance, including leak repairs at various points, will be completed by the end of this week for the whole machine. By the end of next week, the teams will also have completed the bakeout and commissioning of all the collimators, while the installation of coaxial cable for clock distribution for CMS TOTEM has been postponed to the Extended Year-End Technical Stop (EYETS), scheduled to start in December. Following a recent decision, additional electrical tests of the circuits (ELQA and energy extraction insulation tests) for the whole machine have been added to the schedule. The SPS is currentl...

  7. Freeze and restart of the DWPF Scale Glass Melter

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A.S.

    1989-07-31

    After over two years of successful demonstration of many design and operating concepts of the DWPF Melter system, the last Scale Glass Melter campaign was initiated on 6/9/88 and consisted of two parts; (1) simulation of noble metal buildup and (2) freeze and subsequent restart of the melter under various scenarios. The objectives were to simulate a prolonged power loss to major heating elements and to examine the characteristics of transient melter operations during a startup with a limited supply of lid heat. Experimental results indicate that in case of a total power loss to the lower electrodes such as due to noble metal deposition, spinel crystals will begin to form in the SRL 165 composite waste glass pool in 24 hours. The total lid heater power required to initiate joule heating was the same as that during slurry-feeding. Results of a radiative heat transfer analysis in the plenum indicate that under the identical operating conditions, the startup capabilities of the SGM and the DWPF Melter are quite similar, despite a greater lid heater to melt surface area ratio in the DWPF Melter.

  8. Online Scheduling with Delivery Time on a Bounded Parallel Batch Machine with Limited Restart

    National Research Council Canada - National Science Library

    Liu, Hailing; Wan, Long; Yan, Zhigang; Yuan, Jinjiang

    2015-01-01

      We consider the online (over time) scheduling of equal length jobs on a bounded parallel batch machine with batch capacity b to minimize the time by which all jobs have been delivered with limited restart...

  9. Muon Collider Progress: Accelerators

    CERN Document Server

    Zisman, Michael S

    2011-01-01

    A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 \\times 10^34 cm^-2s^-1. Secondly, the beam is initially produce...

  10. Some comparison of restarted GMRES and QMR for linear and nonlinear problems

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, R. [Baylor Univ., Waco, TX (United States); Joubert, W. [Los Alamos National Lab., NM (United States)

    1994-12-31

    Comparisons are made between the following methods: QMR including its transpose-free version, restarted GMRES, and a modified restarted GMRES that uses approximate eigenvectors to improve convergence, For some problems, the modified GMRES is competitive with or better than QMR in terms of the number of matrix-vector products. Also, the GMRES methods can be much better when several similar systems of linear equations must be solved, as in the case of nonlinear problems and ODE problems.

  11. Linear Collider Physics Resource Book Snowmass 2001

    Energy Technology Data Exchange (ETDEWEB)

    Ronan (Editor), M.T.

    2001-06-01

    built in a few years, it would make sense to wait for the results of each accelerator before planning the next one. Thus, we would wait for the results from the Tevatron before planning the LHC experiments, and wait for the LHC before planning any later stage. In reality accelerators require a long time to construct, and they require such specialized resources and human talent that delay can cripple what would be promising opportunities. In any event, we believe that the case for the linear collider is so compelling and robust that we can justify this facility on the basis of our current knowledge, even before the Tevatron and LHC experiments are done. The physics prospects for the linear collider have been studied intensively for more than a decade, and arguments for the importance of its experimental program have been developed from many different points of view. This book provides an introduction and a guide to this literature. We hope that it will allow physicists new to the consideration of linear collider physics to start from their own personal perspectives and develop their own assessments of the opportunities afforded by a linear collider.

  12. The Big Collider

    CERN Multimedia

    Barna-Alper Productions Inc. Toronto

    2005-01-01

    The Large Hadron Collider is a gigantic particle-smasher, designed to discover the origins of the universe. Awe-inspiring in vision and scope, it’s also the most expensive physics experiment in history with a price-tag of 4 billion dollars.Documentary series "Mega builders" : a fast-paced, character-driven show that focuses on the world’s biggest and most intriguing engineering challenges – the projects that are making history, and the people who are making it happen.

  13. Hadron-hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Month, M.; Weng, W.T.

    1983-06-21

    The objective is to investigate whether existing technology might be extrapolated to provide the conceptual framework for a major hadron-hadron collider facility for high energy physics experimentation for the remainder of this century. One contribution to this large effort is to formalize the methods and mathematical tools necessary. In this report, the main purpose is to introduce the student to basic design procedures. From these follow the fundamental characteristics of the facility: its performance capability, its size, and the nature and operating requirements on the accelerator components, and with this knowledge, we can determine the technology and resources needed to build the new facility.

  14. Muon colliders and neutrino factories

    Energy Technology Data Exchange (ETDEWEB)

    Geer, S.; /Fermilab

    2010-09-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate {Omicron}(10{sup 21}) muons/year. This development prepares the way for a new type of neutrino source (Neutrino Factory) and a new type of very high energy lepton-antilepton collider (Muon Collider). This article reviews the motivation, design and R&D for Neutrino Factories and Muon Colliders.

  15. Muon colliders and neutrino factories

    CERN Document Server

    Geer, S

    2012-01-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate O(1021) muons/year. This development prepares the way for a new type of neutrino source (Neutrino Factory) and a new type of very high energy lepton-antilepton collider (Muon Collider). This article reviews the motivation, design and R&D for Neutrino Factories and Muon Colliders.

  16. Detector for a linear collider

    CERN Document Server

    Mnich, J

    2003-01-01

    The proposals under discussion for a new e^{+}e^{-} linear collider with centre-of-mass energies around 1 TeV include designs for large detectors with unprecedented performances in energy, momentum and position resolution. These very stringent requirements are dictated by the precision measurements aimed at this collider to complement the exploratory experiments at the Large Hadron Collider. Here a status report on detector R&D projects for the liner collider is given focused on the technologies under study for the vertex detector, the large tracking chamber and the calorimeters.

  17. Linear collider development at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, J.

    1993-08-01

    Linear collider R&D at SLAC comprises work on the present Stanford Linear Collider (SLC) and work toward the next linear collider (NLC). Recent SLC developments are summarized. NLC studies are divided into hardware-based and theoretical. We report on the status of the NLC Test Accelerator (NLCTA) and the final focus test beam (FFTB), describe plans for ASSET, an installation to measure accelerator structure wakefields, and mention IR design developments. Finally we review recent NLC theoretical studies, ending with the author`s view of next linear collider parameter sets.

  18. Reasons Why Children and Adolescents with ADHD Stop and Restart Taking Medicine.

    Science.gov (United States)

    Brinkman, William B; Simon, John O; Epstein, Jeffery N

    2017-09-12

    To describe the prevalence of reasons why children and adolescents stop and restart attention-deficit/hyperactivity disorder (ADHD) medicine and whether functional impairment is present after stopping medicine. We used the prospective longitudinal cohort from the Multimodal Treatment of Study of Children with ADHD. At the 12 year follow-up when participants were a mean of 21.1 years old, 372 participants (76% male, 64% Caucasian) reported ever taking ADHD medicine. Participants reported the age when they last stopped and/or restarted ADHD medicine and also endorsed reasons for stopping and restarting. Seventy-seven percent (286/372) reported stopping medicine for a month or longer at some time during childhood or adolescence. Participants were a mean of 13.3 years old when they last stopped medicine. The most commonly endorsed reasons for stopping medication related to 1) medicine not needed/helping, 2) side effects, 3) logistical barriers of getting/taking medication, and 4) social concerns/stigma. Seventeen percent (64/372) reported restarting medicine after stopping for a month or longer. Commonly endorsed reasons for restarting related to 1) medicine needed/helped, 2) resolution of logistical barriers to getting/taking. For both stopping and restarting, the proportion endorsing some reasons differed by age range, with the overall pattern suggesting that parental involvement in decisions decreased with age. Nearly all participants had impairment at the assessment after stopping regardless of whether medication was resumed. Different reasons for stopping and/or restarting medicine are relevant at different times for different teens. Tailored strategies may help engage adolescents as full partners in their treatment plan. Copyright © 2017. Published by Elsevier Inc.

  19. Safety Evaluation Report Restart of K-Reactor Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    In April 1991, the Department of Energy (DOE) issued DOE/DP-0084T, Safety Evaluation Report Restart of K-Reactor Savannah River Site.'' The Safety Evaluation Report (SER) documents the results of DOE reviews and evaluations of the programmatic aspects of a large number of issues necessary to be satisfactorily addressed before restart. The issues were evaluated for compliance with the restart criteria included in the SER. The results of those evaluations determined that the restart criteria had been satisfied for some of the issues. However, for most of the issues at least part of the applicable restart criteria had not been found to be satisfied at the time the evaluations were prepared. For those issues, open or confirmatory items were identified that required resolution. In August 1991, DOE issued DOE/DP-0090T, Safety Evaluation Report Restart of K-Reactor Savannah River Site Supplement 1.'' That document was the first Supplement to the April 1991 SER, and documented the resolution of 62 of the open items identified in the SER. This document is the second Supplement to the April 1991 SER. This second SER Supplement documents the resolution of additional open times identified in the SER, and includes a complete list of all remaining SER open items. The resolution of those remaining open items will be documented in future SER Supplements. Resolution of all open items for an issue indicates that its associated restart criteria have been satisfied, and that DOE concludes that the programmatic aspects of the issue have been satisfactorily addressed.

  20. Operational Readiness Review Final Report For F-Canyon Restart. Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, A.F.; Spangler, J.B.

    1995-04-05

    An independent WSRC Operational Readiness Review was performed for the restart of Phase 1 processing in F-Canyon, Building 221-F. Readiness to restart the Second Plutonium Cycle process and solvent recovery was assessed. The ORR was conducted by an ORR board of ten members with the support of a subject matter expert. The chairman and four members were drawn from the Operational Safety Evaluation Department, ESH& QA Division; additional members were drawn from other WSRC divisions, independent of the F-Canyon operating division (NMPD). Based on the results of the readiness verification assessments performed according to the ORR plan and the validation of pre-restart corrective actions, the WSRC independent ORR Board has concluded that the facility has achieved the state of readiness committed to in the Restart Plan. Also, based on the scope of the ORR, it is the opinion of the board that F-Canyon Phase 1 processes can be restarted without undue risk to the safety of the public and onsite workers and without undue risk to the environment.

  1. Test of QCD at colliders

    CERN Document Server

    Shimizu, Shima; The ATLAS collaboration

    2016-01-01

    The ATLAS and CMS collaborations measure QCD processes in a wide kinematic range using proton--proton colliding data at the Large Hadron Collider (LHC). A variety of recent results is presented. The results provide validation of the current understanding of QCD, such as the proton structure and interactions and radiations of partons.

  2. Heavy Neutrinos at Future Colliders

    CERN Document Server

    Dev, P S Bhupal

    2016-01-01

    We discuss the current status and future prospects of heavy neutrino searches at the energy frontier, which might play an important role in vindicating the simplest seesaw paradigm as the new physics responsible for neutrino mass generation. After summarizing the current search limits and potential improvements at hadron colliders, we highlight the unparalleled sensitivities achievable in the clean environment of future lepton colliders.

  3. Challenges in future linear colliders

    CERN Document Server

    Chattopadhyay, S

    2002-01-01

    For decades, electron-positron colliders have been complementing proton-proton colliders. But the circular LEP, the largest e/sup -/e /sup +/ collider, represented an energy limit beyond which energy losses to synchrotron radiation necessitate moving to e/sup -/e/sup + / linear colliders (LCs), thereby raising new challenges for accelerator builders. Japanese-American, German, and European collaborations have presented options for the "Future Linear Collider " (FLC). Key accelerator issues for any FLC option are the achievement of high enough energy and luminosity. Damping rings, taking advantage of the phenomenon of synchrotron radiation, have been developed as the means for decreasing beam size, which is crucial for ensuring a sufficiently high rate of particle-particle collisions. Related challenges are alignment and stability in an environment where even minute ground motion can disrupt performance, and the ability to monitor beam size. The technical challenges exist within a wider context of socioeconomi...

  4. CERN balances linear collider studies

    CERN Multimedia

    ILC Newsline

    2011-01-01

    The forces behind the two most mature proposals for a next-generation collider, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) study, have been steadily coming together, with scientists from both communities sharing ideas and information across the technology divide. In a support of cooperation between the two, CERN in Switzerland, where most CLIC research takes place, recently converted the project-specific position of CLIC Study Leader to the concept-based Linear Collider Study Leader.   The scientist who now holds this position, Steinar Stapnes, is charged with making the linear collider a viable option for CERN’s future, one that could include either CLIC or the ILC. The transition to more involve the ILC must be gradual, he said, and the redefinition of his post is a good start. Though not very much involved with superconducting radiofrequency (SRF) technology, where ILC researchers have made significant advances, CERN participates in many aspect...

  5. Soviet Hadron Collider

    Science.gov (United States)

    Kotchetkov, Dmitri

    2017-01-01

    Rapid growth of the high energy physics program in the USSR during 1960s-1970s culminated with a decision to build the Accelerating and Storage Complex (UNK) to carry out fixed target and colliding beam experiments. The UNK was to have three rings. One ring was to be built with conventional magnets to accelerate protons up to the energy of 600 GeV. The other two rings were to be made from superconducting magnets, each ring was supposed to accelerate protons up to the energy of 3 TeV. The accelerating rings were to be placed in an underground tunnel with a circumference of 21 km. As a 3 x 3 TeV collider, the UNK would make proton-proton collisions with a luminosity of 4 x 1034 cm-1s-1. Institute for High Energy Physics in Protvino was a project leading institution and a site of the UNK. Accelerator and detector research and development studies were commenced in the second half of 1970s. State Committee for Utilization of Atomic Energy of the USSR approved the project in 1980, and the construction of the UNK started in 1983. Political turmoil in the Soviet Union during late 1980s and early 1990s resulted in disintegration of the USSR and subsequent collapse of the Russian economy. As a result of drastic reduction of funding for the UNK, in 1993 the project was restructured to be a 600 GeV fixed target accelerator only. While the ring tunnel and proton injection line were completed by 1995, and 70% of all magnets and associated accelerator equipment were fabricated, lack of Russian federal funding for high energy physics halted the project at the end of 1990s.

  6. [Safely restarting antithrombotic treatment after a gastrointestinal bleed: evidence or gut feeling?].

    Science.gov (United States)

    van der Worp, H Bart

    2016-01-01

    Guidelines for the management of non-variceal upper gastrointestinal haemorrhage recommend restarting anticoagulant therapy after treatment of the haemorrhage in patients with an indication for anticoagulation, such as atrial fibrillation. This recommendation is based on findings in retrospective observational studies, and probably also on common sense: if the cause of the haemorrhage has been treated, the chance of a life-threatening second gastrointestinal haemorrhage when anticoagulation is restarted is likely to be smaller than the chance of a serious thromboembolic complication if anticoagulation is stopped indefinitely. A new, large observational study in patients with atrial fibrillation who had a gastrointestinal bleed while receiving antithrombotic treatment suggests that a restart of oral anticoagulation is associated with a lower risk of death and thromboembolic complications than not resuming anticoagulation, and that the risk of a recurrent bleed is slight. Unfortunately, methodological limitations inherent to most observational studies limit the usefulness of the findings to individual patient cases.

  7. Multiple genetic pathways for restarting DNA replication forks in Escherichia coli K-12.

    OpenAIRE

    Sandler, S J

    2000-01-01

    In Escherichia coli, the primosome assembly proteins, PriA, PriB, PriC, DnaT, DnaC, DnaB, and DnaG, are thought to help to restart DNA replication forks at recombinational intermediates. Redundant functions between priB and priC and synthetic lethality between priA2::kan and rep3 mutations raise the possibility that there may be multiple pathways for restarting replication forks in vivo. Herein, it is shown that priA2::kan causes synthetic lethality when placed in combination with either Delt...

  8. The efficacy of a restart break for recycling with optimal performance depends critically on circadian timing.

    Science.gov (United States)

    Van Dongen, Hans P A; Belenky, Gregory; Vila, Bryan J

    2011-07-01

    Under simulated shift-work conditions, we investigated the efficacy of a restart break for maintaining neurobehavioral functioning across consecutive duty cycles, as a function of the circadian timing of the duty periods. As part of a 14-day experiment, subjects underwent two cycles of five simulated daytime or nighttime duty days, separated by a 34-hour restart break. Cognitive functioning and high-fidelity driving simulator performance were tested 4 times per day during the two duty cycles. Lapses on a psychomotor vigilance test (PVT) served as the primary outcome variable. Selected sleep periods were recorded polysomnographically. The experiment was conducted under standardized, controlled laboratory conditions with continuous monitoring. Twenty-seven healthy adults (13 men, 14 women; aged 22-39 years) participated in the study. Subjects were randomly assigned to a nighttime duty (experimental) condition or a daytime duty (control) condition. The efficacy of the 34-hour restart break for maintaining neurobehavioral functioning from the pre-restart duty cycle to the post-restart duty cycle was compared between these two conditions. Relative to the daytime duty condition, the nighttime duty condition was associated with reduced amounts of sleep, whereas sleep latencies were shortened and slow-wave sleep appeared to be conserved. Neurobehavioral performance measures ranging from lapses of attention on the PVT to calculated fuel consumption on the driving simulators remained optimal across time of day in the daytime duty schedule, but degraded across time of night in the nighttime duty schedule. The 34-hour restart break was efficacious for maintaining PVT performance and other objective neurobehavioral functioning profiles from one duty cycle to the next in the daytime duty condition, but not in the nighttime duty condition. Subjective sleepiness did not reliably track objective neurobehavioral deficits. The 34-hour restart break was adequate for maintaining

  9. Increased capability gas generator for Space Shuttle APU. Development/hot restart test report

    Science.gov (United States)

    1980-01-01

    The design, fabrication, and testing of an increased capability gas generator for use in space shuttles are described. Results show an unlimited hot restart capability in the range of feed pressures from 400 psi to 80 psi. Effects of vacuum on hot restart were not addressed, and only beginning-of-life bed conditions were tested. No starts with bubbles were performed. A minimum expected life of 35 hours or more is projected, and the design will maintain a surface temperature of 350 F or more.

  10. The slings and arrows of LHC restart schedules

    CERN Document Server

    2015-01-01

    We should now have been celebrating the first circulating beams of LHC Run 2, but, as I reported last Tuesday, I find myself instead having to write about a delay in proceedings. Against a backdrop of great progress in the powering tests for running at 6.5 TeV, a short to ground in one of the LHC’s thousands of circuits became apparent on 21 March.   Although a simple job to repair, it is compounded by the fact that the short is in a cold section of the machine, and it might therefore require a few weeks to warm up, carry out the repair and cool down again. Nevertheless, all the signs are good for a great Run 2, and in the grand scheme of things, a delay of weeks in humankind’s quest to understand our universe is little more than the blink of an eye. The impact of the delay on the experiments will be minimal, as 2015 was always foreseen as a year for preparing the upgraded machine for full-scale physics running in 2016-2018. When the LHC’s first run got underway...

  11. Unraveling supersymmetry at future colliders

    Indian Academy of Sciences (India)

    Xerxes Tata

    2004-02-01

    After a quick review of the current limits on sparticle masses, we outline the prospects for their discovery at future colliders. We then proceed to discuss how precision measurements of sparticle masses can provide information about how SM suprpartners acquire their masses. Finally, we examine how we can proceed to establish whether or not any new physics discovered in the future is supersymmetry, and describe how we might zero in on the framework of SUSY breaking. In this connection, we review sparticle mass measurements at future colliders, and point out that some capabilities of experiments at $e^{+}e^{-}$ linear colliders may have been over-stated in the literture.

  12. Physics at Future Hadron Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, Thomas G.

    2002-08-07

    We discuss the physics opportunities and detector challenges at future hadron colliders. As guidelines for energies and luminosities we use the proposed luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of a Very Large Hadron Collider (VLHC). We illustrate the physics capabilities of future hadron colliders for a variety of new physics scenarios (supersymmetry, strong electroweak symmetry breaking, new gauge bosons, compositeness and extra dimensions). We also investigate the prospects of doing precision Higgs physics studies at such a machine, and list selected Standard Model physics rates.

  13. Hadron collider physics at UCR

    Energy Technology Data Exchange (ETDEWEB)

    Kernan, A.; Shen, B.C.

    1997-07-01

    This paper describes the research work in high energy physics by the group at the University of California, Riverside. Work has been divided between hadron collider physics and e{sup +}-e{sup {minus}} collider physics, and theoretical work. The hadron effort has been heavily involved in the startup activities of the D-Zero detector, commissioning and ongoing redesign. The lepton collider work has included work on TPC/2{gamma} at PEP and the OPAL detector at LEP, as well as efforts on hadron machines.

  14. Physics at future hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    U. Baur et al.

    2002-12-23

    We discuss the physics opportunities and detector challenges at future hadron colliders. As guidelines for energies and luminosities we use the proposed luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of a Very Large Hadron Collider (VLHC). We illustrate the physics capabilities of future hadron colliders for a variety of new physics scenarios (supersymmetry, strong electroweak symmetry breaking, new gauge bosons, compositeness and extra dimensions). We also investigate the prospects of doing precision Higgs physics studies at such a machine, and list selected Standard Model physics rates.

  15. QCD at collider energies

    Science.gov (United States)

    Nicolaidis, A.; Bordes, G.

    1986-05-01

    We examine available experimental distributions of transverse energy and transverse momentum, obtained at the CERN pp¯ collider, in the context of quantum chromodynamics. We consider the following. (i) The hadronic transverse energy released during W+/- production. This hadronic transverse energy is made out of two components: a soft component which we parametrize using minimum-bias events and a semihard component which we calculate from QCD. (ii) The transverse momentum of the produced W+/-. If the transverse momentum (or the transverse energy) results from a single gluon jet we use the formalism of Dokshitzer, Dyakonov, and Troyan, while if it results from multiple-gluon emission we use the formalism of Parisi and Petronzio. (iii) The relative transverse momentum of jets. While for W+/- production quarks play an essential role, jet production at moderate pT and present energies is dominated by gluon-gluon scattering and therefore we can study the Sudakov form factor of the gluon. We suggest also how through a Hankel transform of experimental data we can have direct access to the Sudakov form factors of quarks and gluons.

  16. When Black Holes Collide

    Science.gov (United States)

    Baker, John

    2010-01-01

    Among the fascinating phenomena predicted by General Relativity, Einstein's theory of gravity, black holes and gravitational waves, are particularly important in astronomy. Though once viewed as a mathematical oddity, black holes are now recognized as the central engines of many of astronomy's most energetic cataclysms. Gravitational waves, though weakly interacting with ordinary matter, may be observed with new gravitational wave telescopes, opening a new window to the universe. These observations promise a direct view of the strong gravitational dynamics involving dense, often dark objects, such as black holes. The most powerful of these events may be merger of two colliding black holes. Though dark, these mergers may briefly release more energy that all the stars in the visible universe, in gravitational waves. General relativity makes precise predictions for the gravitational-wave signatures of these events, predictions which we can now calculate with the aid of supercomputer simulations. These results provide a foundation for interpreting expect observations in the emerging field of gravitational wave astronomy.

  17. Feedback systems for linear colliders

    CERN Document Server

    Hendrickson, L; Himel, Thomas M; Minty, Michiko G; Phinney, N; Raimondi, Pantaleo; Raubenheimer, T O; Shoaee, H; Tenenbaum, P G

    1999-01-01

    Feedback systems are essential for stable operation of a linear collider, providing a cost-effective method for relaxing tight tolerances. In the Stanford Linear Collider (SLC), feedback controls beam parameters such as trajectory, energy, and intensity throughout the accelerator. A novel dithering optimization system which adjusts final focus parameters to maximize luminosity contributed to achieving record performance in the 1997-98 run. Performance limitations of the steering feedback have been investigated, and improvements have been made. For the Next Linear Collider (NLC), extensive feedback systems are planned as an intregal part of the design. Feedback requiremetns for JLC (the Japanese Linear Collider) are essentially identical to NLC; some of the TESLA requirements are similar but there are significant differences. For NLC, algorithms which incorporate improvements upon the SLC implementation are being prototyped. Specialized systems for the damping rings, rf and interaction point will operate at hi...

  18. Large Hadron Collider nears completion

    CERN Multimedia

    2008-01-01

    Installation of the final component of the Large Hadron Collider particle accelerator is under way along the Franco-Swiss border near Geneva, Switzerland. When completed this summer, the LHC will be the world's largest and most complex scientific instrument.

  19. Physicists dream of supersized collider

    Science.gov (United States)

    Hao, Cindy

    2015-12-01

    Particle physicists in China are hopeful that the Chinese government will allocate 1 billion yuan (about £104m) to design what would be the world's largest particle accelerator - the Circular Electron Positron Collider (CEPC).

  20. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  1. Bottomonium production in hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Brenner Mariotto, C. [Universidade de Caxias do Sul, RS (Brazil). Centro de Ciencias Exatas e Tecnologia]. E-mail: mariotto@if.ufrgs.br; Gay Ducati, M.B. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica. Grupo de Fenomenologia de Particulas em Altas Energias; Ingelman, G. [Uppsala Univ. (Sweden). High Energy Physics

    2004-07-01

    Production of bottomonium in hadronic collisions is studied in the framework of the soft colour approach. We report some results for production of {upsilon} in the Tevatron and predictions for the future Large Hadron Collider (LHC). (author)

  2. [New technology for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, P.M.

    1992-08-12

    This report discusses the following topics on research of microwave amplifiers for linear colliders: Context in current microwave technology development; gated field emission for microwave cathodes; cathode fabrication and tests; microwave cathode design using field emitters; and microwave localization.

  3. Prospects for Future Collider Physics

    CERN Document Server

    Ellis, John

    2016-01-01

    One item on the agenda of future colliders is certain to be the Higgs boson. What is it trying to tell us? The primary objective of any future collider must surely be to identify physics beyond the Standard Model, and supersymmetry is one of the most studied options. it Is supersymmetry waiting for us and, if so, can LHC Run 2 find it? The big surprise from the initial 13-TeV LHC data has been the appearance of a possible signal for a new boson X with a mass ~750 GeV. What are the prospects for future colliders if the X(750) exists? One of the most intriguing possibilities in electroweak physics would be the discovery of non-perturbative phenomena. What are the prospects for observing sphalerons at the LHC or a future collider?

  4. Sfermion production at photon colliders

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, M. E-mail: michael.klasen@desy.de

    2001-10-11

    We calculate total and differential cross-sections for sfermion production in e{sup +}e{sup -} annihilation and in photon-photon collisions with arbitrary photon polarization. The total cross-section at a polarized photon collider is shown to be larger than the e{sup +}e{sup -} annihilation cross-section up to the kinematic limit of the photon collider.

  5. Polarized Electrons for Linear Colliders

    CERN Document Server

    Clendenin, J E; Garwin, E L; Kirby, R E; Luh, D A; Maruyama, T; Prescott, C Y; Sheppard, J C; Turner, J; Prepost, R

    2005-01-01

    Future electron-positron linear colliders require a highly polarized electron beam with a pulse structure that depends primarily on whether the acceleration utilizes warm or superconducting rf structures. The International Linear Collider (ILC) will use cold structures for the main linac. It is shown that a dc-biased polarized photoelectron source such as successfully used for the SLC can meet the charge requirements for the ILC micropulse with a polarization approaching 90%.

  6. 78 FR 69367 - Golden Valley Electric Association: Healy Power Plant Unit #2 Restart

    Science.gov (United States)

    2013-11-19

    ... the restart of Unit 2 and for improvements to the Healy Plant, which include installing additional emissions control to both Unit 1 and Unit 2. Unit 1 is a 25 MW coal-fired boiler and Unit 2 is a 50 MW coal-fired boiler that was constructed in the late 1990s with funding from DOE and AIDEA. The...

  7. Initialization and Restart in Stochastic Local Search: Computing a Most Probable Explanation in Bayesian Networks

    Science.gov (United States)

    Mengshoel, Ole J.; Wilkins, David C.; Roth, Dan

    2010-01-01

    For hard computational problems, stochastic local search has proven to be a competitive approach to finding optimal or approximately optimal problem solutions. Two key research questions for stochastic local search algorithms are: Which algorithms are effective for initialization? When should the search process be restarted? In the present work we investigate these research questions in the context of approximate computation of most probable explanations (MPEs) in Bayesian networks (BNs). We introduce a novel approach, based on the Viterbi algorithm, to explanation initialization in BNs. While the Viterbi algorithm works on sequences and trees, our approach works on BNs with arbitrary topologies. We also give a novel formalization of stochastic local search, with focus on initialization and restart, using probability theory and mixture models. Experimentally, we apply our methods to the problem of MPE computation, using a stochastic local search algorithm known as Stochastic Greedy Search. By carefully optimizing both initialization and restart, we reduce the MPE search time for application BNs by several orders of magnitude compared to using uniform at random initialization without restart. On several BNs from applications, the performance of Stochastic Greedy Search is competitive with clique tree clustering, a state-of-the-art exact algorithm used for MPE computation in BNs.

  8. Removal of floating organic in Hanford Waste Tank 241-C-103 restart plan

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, T.R.; Hanson, C.

    1994-10-03

    The decision whether or not to remove the organic layer from Waste Tank 241-C-103 was deferred until May, 1995. The following restart plan was prepared for removal of the organic if the decision is to remove the organic from the waste tank 241-C-103.

  9. Restart Plan for the Prototype Vertical Denitration Calciner [SD Coversheet has Incorrect Document Number

    Energy Technology Data Exchange (ETDEWEB)

    SUTTER, C.S.

    1999-07-26

    Testing activities on the Prototype Vertical Denitration Calciner at PFP were suspended in January 1997 due to the hold on fissile material handling in the facility. The Restart Plan will govern the transition of the test program from the completion of the activity based startup review; through equipment checkout and surrogate material runs; to resumption of the testing program and transition to unrestricted testing.

  10. Muon muon collider: Feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-18

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup {minus}2} s{sup {minus}1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice--the authors believe--to allow them to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring which has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design.

  11. Final Report for the Restart of the Waste Characterization, Reduction and Repackaging Facility (WCRRF) Contractor Readiness Assessment (CRA)

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Gregory Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-22

    The Los Alamos National Laboratory (LANL or Laboratory) Contractor Readiness Assessment (CRA) required for restart of the Technical Area (TA) 50 Waste Characterization, Reduction, and Repackaging Facility (WCRRF) for remediated nitrate salt (RNS) waste operations was performed in compliance with the requirements of Department of Energy (DOE) Order (O) 425.1D, Verification of Readiness to Start Up or Restart Nuclear Facilities, and LANL procedure FSD-115-001, Verification of Readiness to Start Up or Restart LANL Nuclear Facilities, Activities, and Operations.

  12. Naturalistic field study of the restart break in US commercial motor vehicle drivers: Truck driving, sleep, and fatigue.

    Science.gov (United States)

    Sparrow, Amy R; Mollicone, Daniel J; Kan, Kevin; Bartels, Rachel; Satterfield, Brieann C; Riedy, Samantha M; Unice, Aaron; Van Dongen, Hans P A

    2016-08-01

    Commercial motor vehicle (CMV) drivers in the US may start a new duty cycle after taking a 34-h restart break. A restart break provides an opportunity for sleep recuperation to help prevent the build-up of fatigue across duty cycles. However, the effectiveness of a restart break may depend on its timing, and on how many nighttime opportunities for sleep it contains. For daytime drivers, a 34-h restart break automatically includes two nighttime periods. For nighttime drivers, who are arguably at increased risk of fatigue, a 34-h restart break contains only one nighttime period. To what extent this is relevant for fatigue depends in part on whether nighttime drivers revert back to a nighttime-oriented sleep schedule during the restart break. We conducted a naturalistic field study with 106 CMV drivers working their normal schedules and performing their normal duties. These drivers were studied during two duty cycles and during the intervening restart break. They provided a total of 1260days of data and drove a total of 414,937 miles during the study. Their duty logs were used to identify the periods when they were on duty and when they were driving and to determine their duty cycles and restart breaks. Sleep/wake patterns were measured continuously by means of wrist actigraphy. Fatigue was assessed three times per day by means of a brief psychomotor vigilance test (PVT-B) and a subjective sleepiness scale. Data from a truck-based lane tracking and data acquisition system were used to compute lane deviation (variability in lateral lane position). Statistical analyses focused on 24-h patterns of duty, driving, sleep, PVT-B performance, subjective sleepiness, and lane deviation. Duty cycles preceded by a restart break containing only one nighttime period (defined as 01:00-05:00) were compared with duty cycles preceded by a restart break containing more than one nighttime period. During duty cycles preceded by a restart break with only one nighttime period, drivers

  13. Collider to use cold technology

    CERN Document Server

    Cartlidge, Edwin

    2004-01-01

    The International Linear Collider (ILC) is being developed for use by particle physicists to make detailed studies of the Higgs boson and many other new particles. The two technologies for the ILC use different types of cavities to accelerate electrons and positrons. The German technology involves superconducting cavities operating at 2 K, whereas the approach proposed by the US and Japan relied on copper cavities that would be run at room temperature. However, due to the huge cost of the linear collider the physicists selected only one. Following evaluation of limitations of each cavity, the physicists opted for the superconducting approach. Assuming that the design work is completed on time, and if funding agencies and politicians can agree on where to build the collider, construction of the machine could start by 2010. (Edited abstract).

  14. The collider of the future?

    CERN Multimedia

    CERN Audiovisual Service

    2009-01-01

    Why are two studies for one linear collider being conducted in parallel? This is far from a duplication of effort or a waste of resources, since the two studies reflect a complementary strategy aimed at providing the best technology for future physics. On Friday 12 June CERN hosted the first joint meeting between CLIC and ILC, which led to a host of good results and important decisions. The International Linear Collider (ILC) and Compact Linear Collider (CLIC) studies both call for cutting-edge technologies. At first glance they may appear to be in competition, but they are in fact complementary and have a common objective – namely to propose a design , as soon as possible and at the lowest possible cost, for the linear accelerator best suited to taking over the baton of physics research at the high-energy frontier after the LHC.

  15. Physics beyond Colliders Kickoff Workshop

    CERN Document Server

    2016-01-01

    The aim of the workshop is to explore the opportunities offered by the CERN accelerator complex and infrastructure to get new insights into some of today's outstanding questions in particle physics through projects complementary to high-energy colliders and other initiatives in the world. The focus is on fundamental physics questions that are similar in spirit to those addressed by high-energy colliders, but that may require different types of experiments. The kickoff workshop is intended to stimulate new ideas for such projects, for which we encourage the submission of abstracts.

  16. Workshop on Physics Beyond Colliders

    CERN Document Server

    2016-01-01

    The aim of the workshop is to explore the opportunities offered by the CERN accelerator complex and infrastructure to get new insights into some of today's outstanding questions in particle physics through projects complementary to high-energy colliders and other initiatives in the world. The focus is on fundamental physics questions that are similar in spirit to those addressed by high-energy colliders, but that may require different types of experiments. The kick-off workshop is intended to stimulate new ideas for such projects, for which we encourage the submission of abstracts.

  17. Use of Checkpoint-Restart for Complex HEP Software on Traditional Architectures and Intel MIC

    CERN Document Server

    Arya, Kapil; Dotti, Andrea; Elmer, Peter

    2013-01-01

    Process checkpoint-restart is a technology with great potential for use in HEP workflows. Use cases include debugging, reducing the startup time of applications both in offline batch jobs and the High Level Trigger, permitting job preemption in environments where spare CPU cycles are being used opportunistically and efficient scheduling of a mix of multicore and single-threaded jobs. We report on tests of checkpoint-restart technology using CMS software, Geant4-MT (multi-threaded Geant4), and the DMTCP (Distributed Multithreaded Checkpointing) package. We analyze both single- and multi-threaded applications and test on both standard Intel x86 architectures and on Intel MIC. The tests with multi-threaded applications on Intel MIC are used to consider scalability and performance. These are considered an indicator of what the future may hold for many-core computing.

  18. Muon Muon Collider: Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, J.C.; Palmer, R.B.; /Brookhaven; Tollestrup, A.V.; /Fermilab; Sessler, A.M.; /LBL, Berkeley; Skrinsky, A.N.; /Novosibirsk, IYF; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. /Fermilab /Brookhaven /Wisconsin U., Madison /Tel Aviv U. /Indiana U. /UCLA /LBL, Berkeley /SLAC /Argonne /Sobolev IM, Novosibirsk /UC, Davis /Munich, Tech. U. /Virginia U. /KEK, Tsukuba /DESY /Novosibirsk, IYF /Jefferson Lab /Mississippi U. /SUNY, Stony Brook /MIT /Columbia U. /Fairfield U. /UC, Berkeley

    2012-04-05

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring wich has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle

  19. Economic evaluation of strategies for restarting anticoagulation therapy after a first event of unprovoked venous thromboembolism.

    Science.gov (United States)

    Monahan, M; Ensor, J; Moore, D; Fitzmaurice, D; Jowett, S

    2017-08-01

    Essentials Correct duration of treatment after a first unprovoked venous thromboembolism (VTE) is unknown. We assessed when restarting anticoagulation was worthwhile based on patient risk of recurrent VTE. When the risk over a one-year period is 17.5%, restarting is cost-effective. However, sensitivity analyses indicate large uncertainty in the estimates. Background Following at least 3 months of anticoagulation therapy after a first unprovoked venous thromboembolism (VTE), there is uncertainty about the duration of therapy. Further anticoagulation therapy reduces the risk of having a potentially fatal recurrent VTE but at the expense of a higher risk of bleeding, which can also be fatal. Objective An economic evaluation sought to estimate the long-term cost-effectiveness of using a decision rule for restarting anticoagulation therapy vs. no extension of therapy in patients based on their risk of a further unprovoked VTE. Methods A Markov patient-level simulation model was developed, which adopted a lifetime time horizon with monthly time cycles and was from a UK National Health Service (NHS)/Personal Social Services (PSS) perspective. Results Base-case model results suggest that treating patients with a predicted 1 year VTE risk of 17.5% or higher may be cost-effective if decision makers are willing to pay up to £20 000 per quality adjusted life year (QALY) gained. However, probabilistic sensitivity analysis shows that the model was highly sensitive to overall parameter uncertainty and caution is warranted in selecting the optimal decision rule on cost-effectiveness grounds. Univariate sensitivity analyses indicate variables such as anticoagulation therapy disutility and mortality risks were very influential in driving model results. Conclusion This represents the first economic model to consider the use of a decision rule for restarting therapy for unprovoked VTE patients. Better data are required to predict long-term bleeding risks during therapy in this

  20. The design and implementation of Berkeley Lab's linuxcheckpoint/restart

    Energy Technology Data Exchange (ETDEWEB)

    Duell, Jason

    2005-04-30

    This paper describes Berkeley Linux Checkpoint/Restart (BLCR), a linux kernel module that allows system-level checkpoints on a variety of Linux systems. BLCR can be used either as a stand alone system for checkpointing applications on a single machine, or as a component by a scheduling system or parallel communication library for checkpointing and restoring parallel jobs running on multiple machines. Integration with Message Passing Interface (MPI) and other parallel systems is described.

  1. An intelligent multi-restart memetic algorithm for box constrained global optimisation.

    Science.gov (United States)

    Sun, J; Garibaldi, J M; Krasnogor, N; Zhang, Q

    2013-01-01

    In this paper, we propose a multi-restart memetic algorithm framework for box constrained global continuous optimisation. In this framework, an evolutionary algorithm (EA) and a local optimizer are employed as separated building blocks. The EA is used to explore the search space for very promising solutions (e.g., solutions in the attraction basin of the global optimum) through its exploration capability and previous EA search history, and local search is used to improve these promising solutions to local optima. An estimation of distribution algorithm (EDA) combined with a derivative free local optimizer, called NEWUOA (M. Powell, Developments of NEWUOA for minimization without derivatives. Journal of Numerical Analysis, 28:649-664, 2008), is developed based on this framework and empirically compared with several well-known EAs on a set of 40 commonly used test functions. The main components of the specific algorithm include: (1) an adaptive multivariate probability model, (2) a multiple sampling strategy, (3) decoupling of the hybridisation strategy, and (4) a restart mechanism. The adaptive multivariate probability model and multiple sampling strategy are designed to enhance the exploration capability. The restart mechanism attempts to make the search escape from local optima, resorting to previous search history. Comparison results show that the algorithm is comparable with the best known EAs, including the winner of the 2005 IEEE Congress on Evolutionary Computation (CEC2005), and significantly better than the others in terms of both the solution quality and computational cost.

  2. Michaelis-Menten reaction scheme as a unified approach towards the optimal restart problem.

    Science.gov (United States)

    Rotbart, Tal; Reuveni, Shlomi; Urbakh, Michael

    2015-12-01

    We study the effect of restart, and retry, on the mean completion time of a generic process. The need to do so arises in various branches of the sciences and we show that it can naturally be addressed by taking advantage of the classical reaction scheme of Michaelis and Menten. Stopping a process in its midst-only to start it all over again-may prolong, leave unchanged, or even shorten the time taken for its completion. Here we are interested in the optimal restart problem, i.e., in finding a restart rate which brings the mean completion time of a process to a minimum. We derive the governing equation for this problem and show that it is exactly solvable in cases of particular interest. We then continue to discover regimes at which solutions to the problem take on universal, details independent forms which further give rise to optimal scaling laws. The formalism we develop, and the results obtained, can be utilized when optimizing stochastic search processes and randomized computer algorithms. An immediate connection with kinetic proofreading is also noted and discussed.

  3. An asynchronous writing method for restart files in the gysela code in prevision of exascale systems*

    Directory of Open Access Journals (Sweden)

    Thomine O.

    2013-12-01

    Full Text Available The present work deals with an optimization procedure developed in the full-f global GYrokinetic SEmi-LAgrangian code (GYSELA. Optimizing the writing of the restart files is necessary to reduce the computing impact of crashes. These files require a very large memory space, and particularly so for very large mesh sizes. The limited bandwidth of the data pipe between the comput- ing nodes and the storage system induces a non-scalable part in the GYSELA code, which increases with the mesh size. Indeed the transfer time of RAM to data depends linearly on the files size. The necessity of non synchronized writing-in-file procedure is therefore crucial. A new GYSELA module has been developed. This asynchronous procedure allows the frequent writ- ing of the restart files, whilst preventing a severe slowing down due to the limited writing bandwidth. This method has been improved to generate a checksum control of the restart files, and automatically rerun the code in case of a crash for any cause.

  4. Michaelis-Menten reaction scheme as a unified approach towards the optimal restart problem

    Science.gov (United States)

    Rotbart, Tal; Reuveni, Shlomi; Urbakh, Michael

    2015-12-01

    We study the effect of restart, and retry, on the mean completion time of a generic process. The need to do so arises in various branches of the sciences and we show that it can naturally be addressed by taking advantage of the classical reaction scheme of Michaelis and Menten. Stopping a process in its midst—only to start it all over again—may prolong, leave unchanged, or even shorten the time taken for its completion. Here we are interested in the optimal restart problem, i.e., in finding a restart rate which brings the mean completion time of a process to a minimum. We derive the governing equation for this problem and show that it is exactly solvable in cases of particular interest. We then continue to discover regimes at which solutions to the problem take on universal, details independent forms which further give rise to optimal scaling laws. The formalism we develop, and the results obtained, can be utilized when optimizing stochastic search processes and randomized computer algorithms. An immediate connection with kinetic proofreading is also noted and discussed.

  5. RDEL: Restart Differential Evolution algorithm with Local Search Mutation for global numerical optimization

    Directory of Open Access Journals (Sweden)

    Ali Wagdy Mohamed

    2014-11-01

    Full Text Available In this paper, a novel version of Differential Evolution (DE algorithm based on a couple of local search mutation and a restart mechanism for solving global numerical optimization problems over continuous space is presented. The proposed algorithm is named as Restart Differential Evolution algorithm with Local Search Mutation (RDEL. In RDEL, inspired by Particle Swarm Optimization (PSO, a novel local mutation rule based on the position of the best and the worst individuals among the entire population of a particular generation is introduced. The novel local mutation scheme is joined with the basic mutation rule through a linear decreasing function. The proposed local mutation scheme is proven to enhance local search tendency of the basic DE and speed up the convergence. Furthermore, a restart mechanism based on random mutation scheme and a modified Breeder Genetic Algorithm (BGA mutation scheme is combined to avoid stagnation and/or premature convergence. Additionally, an exponent increased crossover probability rule and a uniform scaling factors of DE are introduced to promote the diversity of the population and to improve the search process, respectively. The performance of RDEL is investigated and compared with basic differential evolution, and state-of-the-art parameter adaptive differential evolution variants. It is discovered that the proposed modifications significantly improve the performance of DE in terms of quality of solution, efficiency and robustness.

  6. Physics at the Fermilab Collider

    Energy Technology Data Exchange (ETDEWEB)

    Shochet, M.J. [Univ. of Chicago, Chicago, IL (United States)

    1994-09-01

    The CDF and D0 experiments at the Fermilab Tevatron Collider have produced many results from the search for the top quark, the study of both the electroweak and strong interactions, the production and decay of b quarks, and the search for new high mass objects. A sample of recently obtained results are presented.

  7. Working group report: Collider Physics

    Indian Academy of Sciences (India)

    Sunanda Banerjee; Rohini M Godbole; Sreerup Raychaudhuri; Ben Allanach; Sunanda Banerjee; Satyaki Bhattacharyya; Debajyoti Choudhury; Siba Prasad Das; Anindya Datta; Rohini M Godbole; Monoranjan Guchait; Sabine Kraml; Gobinda Majumdar; David Miller; Margarete Mühlleitner; Nobuchika Okada; Maxim Perelstein; Santosh K Rai; Sreerup Raychaudhuri; Saurabh D Rindani; D P Roy; K Sridhar; Rishikesh Vaidya; D Zeppenfeld

    2006-10-01

    This is summary of the activities of the working group on collider physics in the IXth Workshop on High Energy Physics Phenomenology (WHEPP-9) held at the Institute of Physics, Bhubaneswar, India in January 2006. Some of the work subsequently done on these problems by the subgroups formed during the workshop is included in this report.

  8. B physics at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Butler, J.N.; /Fermilab

    2005-09-01

    This paper discusses the physics opportunity and challenges for doing high precision B physics experiments at hadron colliders. It describes how these challenges have been addressed by the two currently operating experiments, CDF and D0, and how they are addressed by three experiments, ATLAS, CMS, and LHCb, at the LHC.

  9. Electroweak results from hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Marcel Demarteau

    1999-09-02

    A very brief summary of recent electroweak results from hadron colliders is given. The emphasis is placed on inclusive W{sup {+-}} and Z{sup 0} production, the measurement of the mass of the W boson and the measurement of trilinear gauge boson couplings.

  10. Fast Timing for Collider Detectors

    CERN Document Server

    CERN. Geneva

    2017-01-01

    Advancements in fast timing particle detectors have opened up new possibilities to design collider detectors that fully reconstruct and separate event vertices and individual particles in the time domain. The applications of these techniques are considered for the physics at HL-LHC.

  11. Hard QCD at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Moch, S.

    2008-02-15

    We review the status of QCD at hadron colliders with emphasis on precision predictions and the latest theoretical developments for cross sections calculations to higher orders. We include an overview of our current information on parton distributions and discuss various Standard Model reactions such as W{sup {+-}}/Z-boson, Higgs boson or top quark production. (orig.)

  12. The collider of the future?

    CERN Multimedia

    2009-01-01

    Why are two studies for one linear collider being conducted in parallel? This is far from a duplication of effort or a waste of resources, since the two studies reflect a complementary strategy aimed at providing the best technology for future physics. On Friday 12 June CERN hosted the first joint meeting between CLIC, ILC and the CERN management.

  13. World lays groundwork for future linear collider

    CERN Multimedia

    Feder, Toni

    2010-01-01

    "New physics from the Large Hadron Collider can best be explored with a large lepton collider; realizing one will require mobilizing accelerator and particle physicists, funding agencies, and politicians" (3 pages)

  14. P{bar P} collider physics

    Energy Technology Data Exchange (ETDEWEB)

    Demarteau, M. [State Univ. of New York, Stony Brook, NY (United States)

    1992-04-01

    A brief introduction to {bar p}p collider physics is given. Selected results from the collider experiments at the CERN S{bar p}pS and the Tevatron collider are described. The emphasis is on experimental aspects of {bar p}p collisions. Minimum bias physics and the production of jets, Intermediate Vector Bosons and heavy flavors is reviewed. The outlook for physics at hadron colliders for the near future is briefly discussed.

  15. Muon Muon Collider: Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, J.C.; Palmer, R.B.; /Brookhaven; Tollestrup, A.V.; /Fermilab; Sessler, A.M.; /LBL, Berkeley; Skrinsky, A.N.; /Novosibirsk, IYF; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. /Fermilab /Brookhaven /Wisconsin U., Madison /Tel Aviv U. /Indiana U. /UCLA /LBL, Berkeley /SLAC /Argonne /Sobolev IM, Novosibirsk /UC, Davis /Munich, Tech. U. /Virginia U. /KEK, Tsukuba /DESY /Novosibirsk, IYF /Jefferson Lab /Mississippi U. /SUNY, Stony Brook /MIT /Columbia U. /Fairfield U. /UC, Berkeley

    2012-04-05

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring wich has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle

  16. Polarized proton collider at RHIC

    Science.gov (United States)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S. Y.; Luccio, A.; MacKay, W. W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A. N.

    2003-03-01

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998 [2]), reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to s=500 GeV.

  17. Crab Cavities for Linear Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Burt, G.; Ambattu, P.; Carter, R.; Dexter, A.; Tahir, I.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Beard, C.; Dykes, M.; Goudket, P.; Kalinin, A.; Ma, L.; McIntosh, P.; /Daresbury; Shulte, D.; /CERN; Jones, Roger M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.; Bellantoni, L.; Chase, B.; Church, M.; Khabouline, T.; Latina, A.; /Fermilab; Adolphsen, C.; Li, Z.; Seryi, Andrei; /SLAC

    2011-11-08

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  18. Crab cavities for linear colliders

    CERN Document Server

    Burt, G; Carter, R; Dexter, A; Tahir, I; Beard, C; Dykes, M; Goudket, P; Kalinin, A; Ma, L; McIntosh, P; Shulte, D; Jones, Roger M; Bellantoni, L; Chase, B; Church, M; Khabouline, T; Latina, A; Adolphsen, C; Li, Z; Seryi, Andrei; Xiao, L

    2008-01-01

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  19. Collective accelerator for electron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, R.J.

    1985-05-13

    A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch.

  20. Extra dimensions at particle colliders

    Energy Technology Data Exchange (ETDEWEB)

    Dvergsnes, Erik Wolden

    2004-08-01

    This thesis consists of an introduction where we consider different aspects of theories involving extra dimensions, together with four research publications (Papers I-IV) attached at the end. The introductional chapters should serve as background material for better understanding the models on which the articles are based. In Chap. 4 we also present some plots not included in the papers. The topic of Papers I-III is graviton induced Bremsstrahlung. In Paper I we consider the contribution to this process from graviton exchange through gluon-gluon fusion at the LHC, compared to the QED background. Only final-state radiation is considered in Paper I, whereas in Paper II we extend this work to include also the quark-antiquark annihilation with graviton exchange, as well as initial-state radiation for both graviton and Standard Model exchange. Paper III is a study of graviton-induced Bremsstrahlung at e{sup +}e{sup -} colliders, including both initial- and final-state radiation. Paper IV is devoted to a study of the center-edge asymmetry at hadron colliders, an asymmetry which previously had been studied for e{sup +}e{sup -} colliders. The center-edge asymmetry can be used as a method of distinguishing between spin-1 and spin-2 exchange, something which will be of major importance if a signal is observed.

  1. Management of Invasive Fungal Infections in Pediatric Acute Leukemia and the Appropriate Time for Restarting Chemotherapy

    Directory of Open Access Journals (Sweden)

    Özlem Tüfekçi

    2015-12-01

    Full Text Available INTRODUCTION: Rapid and effective treatment of invasive fungal infection (IFI in patients with leukemia is important for survival. In this study, we aimed to describe variations regarding clinical features, treatment modalities, time of restarting chemotherapy, and outcome in children with IFI and acute leukemia (AL. METHODS: The charts of all pediatric AL patients in our clinic between the years of 2001 and 2013 were retrospectively reviewed. All patients received prophylactic fluconazole during the chemotherapy period. RESULTS: IFI was identified in 25 (14% of 174 AL patients. Most of them were in the consolidation phase of chemotherapy and the patients had severe neutropenia. The median time between leukemia diagnosis and definition of IFI was 122 days. Twenty-four patients had pulmonary IFI. The most frequent finding on computed tomography was typical parenchymal nodules. The episodes were defined as proven in 4 (16% patients, probable in 7 (28% patients, and possible in 14 (56% patients. The median time for discontinuation of chemotherapy was 27 days. IFI was treated successfully in all patients with voriconazole, amphotericin B, caspofungin, or posaconazole alone or in combination. Chemotherapy was restarted in 50% of the patients safely within 4 weeks and none of those patients experienced reactivation of IFI. All of them were given secondary prophylaxis. The median time for antifungal treatment and for secondary prophylaxis was 26 and 90 days, respectively. None of the patients died due to IFI. DISCUSSION AND CONCLUSION: Our data show that rapid and effective antifungal therapy with rational treatment modalities may decrease the incidence of death and that restarting chemotherapy within several weeks may be safe in children with AL and IFI.

  2. Delayed Puberty

    DEFF Research Database (Denmark)

    Kolby, Nanna; Busch, Alexander Siegfried; Juul, Anders

    2017-01-01

    Delayed puberty can be a source of great concern and anxiety, although it usually is caused by a self-limiting variant of the normal physiological timing named constitutional delay of growth and puberty (CDGP). Delayed puberty can, however, also be the first presentation of a permanent condition ...... mineral density) and psychological (e.g., low self-esteem) and underline the importance of careful clinical assessment of the patients.......Delayed puberty can be a source of great concern and anxiety, although it usually is caused by a self-limiting variant of the normal physiological timing named constitutional delay of growth and puberty (CDGP). Delayed puberty can, however, also be the first presentation of a permanent condition...

  3. Delayed fission

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    Delayed fission is a nuclear decay process that couples {beta} decay and fission. In the delayed fission process, a parent nucleus undergoes {beta} decay and thereby populates excited states in the daughter. If these states are of energies comparable to or greater than the fission barrier of the daughter, then fission may compete with other decay modes of the excited states in the daughter. In this paper, mechanism and some experiments of the delayed fission will be discussed. (author)

  4. Colliding with a crunching bubble

    Energy Technology Data Exchange (ETDEWEB)

    Freivogel, Ben; Freivogel, Ben; Horowitz, Gary T.; Shenker, Stephen

    2007-03-26

    In the context of eternal inflation we discuss the fate of Lambda = 0 bubbles when they collide with Lambda< 0 crunching bubbles. When the Lambda = 0 bubble is supersymmetric, it is not completely destroyed by collisions. If the domain wall separating the bubbles has higher tension than the BPS bound, it is expelled from the Lambda = 0 bubble and does not alter its long time behavior. If the domain wall saturates the BPS bound, then it stays inside the Lambda = 0 bubble and removes a finite fraction of future infinity. In this case, the crunch singularity is hidden behind the horizon of a stable hyperbolic black hole.

  5. Muon Colliders and Neutrino Factories

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel M. [IIT, Chicago

    2015-05-29

    Muon colliders and neutrino factories are attractive options for future facilities aimed at achieving the highest lepton-antilepton collision energies and precision measurements of Higgs boson and neutrino mixing matrix parameters. The facility performance and cost depend on how well a beam of muons can be cooled. Recent progress in muon cooling design studies and prototype tests nourishes the hope that such facilities could be built starting in the coming decade. The status of the key technologies and their various demonstration experiments is summarized. Prospects "post-P5" are also discussed.

  6. Testing Saturation at Hadron Colliders

    CERN Document Server

    Marquet, C

    2003-01-01

    We extend the saturation models a la Golec-Biernat and Wusthoff to cross-sections of hard processes initiated by virtual-gluon probes separated by large rapidity intervals at hadron colliders. We derive their analytic expressions and apply them to physical examples, such as saturation effects for Mueller-Navelet jets. By comparison to gamma*-gamma* cross-sections we find a more abrupt transition to saturation. We propose to study observables with a potentially clear saturation signal and to use heavy vector and flavored mesons as alternative virtual-gluon probes.

  7. Muon Colliders and Neutrino Factories

    CERN Document Server

    Kaplan, Daniel M

    2014-01-01

    Muon colliders and neutrino factories are attractive options for future facilities aimed at achieving the highest lepton-antilepton collision energies and precision measurements of Higgs boson and neutrino mixing matrix parameters. The facility performance and cost depend on how well a beam of muons can be cooled. Recent progress in muon cooling design studies and prototype tests nourishes the hope that such facilities could be built starting in the coming decade. The status of the key technologies and their various demonstration experiments is summarized. Prospects "post-P5" are also discussed.

  8. Top production at hadron colliders

    Indian Academy of Sciences (India)

    Albert De Roeck

    2012-10-01

    New results on top quark production are presented from four hadron collider experiments: CDF and D0 at the Tevatron, and ATLAS and CMS at the LHC. Cross-sections for single top and top pair production are discussed, as well as results on the top–antitop production asymmetry and searches for new physics including top quarks. The results are based on data samples of up to 5.4 fb-1 for the Tevatron experiments and 1.1 fb−1 for the LHC experiments.

  9. Tevatron instrumentation: boosting collider performance

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir; Jansson, Andreas; Moore, Ronald; /Fermilab

    2006-05-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches, many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for the next big machines--LHC and ILC.

  10. Rheology and FTIR studies of model waxy crude oils with relevance to gelled pipeline restart

    Energy Technology Data Exchange (ETDEWEB)

    Magda, J.J.; Guimeraes, K.; Deo, M.D. [Utah Univ., Salt Lake City, UT (United States). Dept. of Chemical Engineering; Venkatesan, R.; Montesi, A. [Chevron Energy Technology Co., Houston, TX (United States)

    2008-07-01

    Gels composed of wax crystals may sometimes form when crude oils are transported in pipelines when ambient temperatures are low. The gels may stop the pipe flow, making it difficult or even impossible to restart the flow without breaking the pipe. Rheology and FTIR techniques were used to study the problem and to characterize transparent model waxy crude oils in pipeline flow experiments. These model oils were formulated without any highly volatile components to enhance the reproducibility of the rheology tests. Results were presented for the time- and temperature-dependent rheology of the model waxy crude oils as obtained in linear oscillatory shear and in creep-recovery experiments. The model oils were shown to exhibit many of the rheological features reported for real crude oils, such as 3 distinct apparent yield stresses, notably static yield stress, dynamic yield stress, and elastic-limit yield stress. It was concluded that of the 3, the static yield stress value, particularly its time dependence, can best be used to predict the restart behaviour observed for the same gel in model pipelines.

  11. Investigation of Loop Heat Pipe Survival and Restart After Extreme Cold Environment Exposure

    Science.gov (United States)

    Golliher, Eric; Ku, Jentung; Licari, Anthony; Sanzi, James

    2010-01-01

    NASA plans human exploration near the South Pole of the Moon, and other locations where the environment is extremely cold. This paper reports on the heat transfer performance of a loop heat pipe (LHP) exposed to extreme cold under the simulated reduced gravitational environment of the Moon. A common method of spacecraft thermal control is to use a LHP with ammonia working fluid. Typically, a small amount of heat is provided either by electrical heaters or by environmental design, such that the LHP condenser temperature never drops below the freezing point of ammonia. The concern is that a liquid-filled, frozen condenser would not restart, or that a thawing condenser would damage the tubing due to the expansion of ammonia upon thawing. This paper reports the results of an experimental investigation of a novel approach to avoid these problems. The LHP compensation chamber (CC) is conditioned such that all the ammonia liquid is removed from the condenser and the LHP is nonoperating. The condenser temperature is then reduced to below that of the ammonia freezing point. The LHP is then successfully restarted.

  12. Quantification of the fungal fraction released from various preloaded fibrous filters during a simulated ventilation restart.

    Science.gov (United States)

    Morisseau, K; Joubert, A; Le Coq, L; Andres, Y

    2017-05-01

    This study aimed to demonstrate that particles, especially those associated with fungi, could be released from fibrous filters used in the air-handling unit (AHU) of heating, ventilation and air-conditioning (HVAC) systems during ventilation restarts. Quantification of the water retention capacity and SEM pictures of the filters was used to show the potential for fungal proliferation in unused or preloaded filters. Five fibrous filters with various particle collection efficiencies were studied: classes G4, M5, M6, F7, and combined F7 according to European standard EN779:2012. Filters were clogged with micronized rice particles containing the fungus Penicillium chrysogenum and then incubated for three weeks at 25°C and 90% relative humidity. The results indicated that the five clogged tested filters had various fungal growth capacities depending on their water retention capacity. Preloaded filters were subjected to a simulated ventilation restart in a controlled filtration device to quantify that the fraction of particles released was around 1% for the G4, 0.1% for the M5 and the M6, and 0.001% for the F7 and the combined F7 filter. The results indicate that the likelihood of fungal particle release by low efficiency filters is significantly higher than by high efficiency filters. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Data assimilation for unsaturated flow models with restart adaptive probabilistic collocation based Kalman filter

    Energy Technology Data Exchange (ETDEWEB)

    Man, Jun; Li, Weixuan; Zeng, Lingzao; Wu, Laosheng

    2016-06-01

    The ensemble Kalman filter (EnKF) has gained popularity in hydrological data assimilation problems. As a Monte Carlo based method, a relatively large ensemble size is usually required to guarantee the accuracy. As an alternative approach, the probabilistic collocation based Kalman filter (PCKF) employs the polynomial chaos to approximate the original system. In this way, the sampling error can be reduced. However, PCKF suffers from the so-called "curse of dimensionality". When the system nonlinearity is strong and number of parameters is large, PCKF could be even more computationally expensive than EnKF. Motivated by most recent developments in uncertainty quantification, we propose a restart adaptive probabilistic collocation based Kalman filter (RAPCKF) for data assimilation in unsaturated flow problems. During the implementation of RAPCKF, the important parameters are identified and active PCE basis functions are adaptively selected. The "restart" technology is used to eliminate the inconsistency between model parameters and states. The performance of RAPCKF is tested with numerical cases of unsaturated flow models. It is shown that RAPCKF is more efficient than EnKF with the same computational cost. Compared with the traditional PCKF, the RAPCKF is more applicable in strongly nonlinear and high dimensional problems.

  14. RESTART simulation of non-Markov consecutive-k-out-of-n: F repairable systems

    Energy Technology Data Exchange (ETDEWEB)

    Villen-Altamirano, Jose, E-mail: jvillen@eui.upm.e [Departamento de Matematica Aplicada (E.U. Informatica), Universidad Politecnica de Madrid, Calle Arboleda s/n, 28031 Madrid (Spain)

    2010-03-15

    The reliability of consecutive-k-out-of-n: F repairable systems and (k-1)-step Markov dependence is studied. The model analyzed in this paper is more general than those of previous studies given that repair time and component lifetimes are random variables that follow a general distribution. The system has one repair service which adopts a priority repair rule based on system failure risk. Since crude simulation has proved to be inefficient for highly dependable systems, the RESTART method was used for the estimation of steady-state unavailability, MTBF and unreliability. Probabilities up to the order of 10{sup -16} have been accurately estimated with little computational effort. In this method, a number of simulation retrials are performed when the process enters regions of the state space where the chance of occurrence of a rare event (e.g., a system failure) is higher. The main difficulty for the application of this method is to find a suitable function, called the importance function, to define the regions. Given the simplicity involved in changing some model assumptions with RESTART, the importance function used in this paper could be useful for dependability estimation of many systems.

  15. Standard Model Background of the Cosmological Collider

    CERN Document Server

    Chen, Xingang; Xianyu, Zhong-Zhi

    2016-01-01

    The inflationary universe can be viewed as a "Cosmological Collider" with energy of Hubble scale, producing very massive particles and recording their characteristic signals in primordial non-Gaussianities. To utilize this collider to explore any new physics at very high scales, it is a prerequisite to understand the background signals from the particle physics Standard Model. In this paper we describe the Standard Model background of the Cosmological Collider.

  16. Prospects for Colliders and Collider Physics to the 1 PeV Energy Scale

    CERN Document Server

    King, B J

    2000-01-01

    A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing our progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC -- one each of e+e- and hadron colliders and three muon colliders -- and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R&D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory

  17. High Energy Hadron Colliders - Report of the Snowmass 2013 Frontier Capabilities Hadron Collider Study Group

    CERN Document Server

    Barletta, William; Battaglia, Marco; Klute, Markus; Mangano, Michelangelo; Prestemon, Soren; Rossi, Lucio; Skands, Peter

    2013-01-01

    High energy hadron colliders have been the tools for discovery at the highest mass scales of the energy frontier from the SppS, to the Tevatron and now the LHC. This report reviews future hadron collider projects from the high luminosity LHC upgrade to a 100 TeV hadron collider in a large tunnel, the underlying technology challenges and R&D directions and presents a series of recommendations for the future development of hadron collider research and technology.

  18. Disentangling heavy flavor at colliders

    Science.gov (United States)

    Ilten, Philip; Rodd, Nicholas L.; Thaler, Jesse; Williams, Mike

    2017-09-01

    We propose two new analysis strategies for studying charm and beauty quarks at colliders. The first strategy is aimed at testing the kinematics of heavy-flavor quarks within an identified jet. Here, we use the SoftDrop jet-declustering algorithm to identify two subjets within a large-radius jet, using subjet flavor tagging to test the heavy-quark splitting functions of QCD. For subjets containing a J /ψ or ϒ , this declustering technique can also help probe the mechanism for quarkonium production. The second strategy is aimed at isolating heavy-flavor production from gluon splitting. Here, we introduce a new FlavorCone algorithm, which smoothly interpolates from well-separated heavy-quark jets to the gluon-splitting regime where jets overlap. Because of its excellent ability to identify charm and beauty hadrons, the LHCb detector is ideally suited to pursue these strategies, though similar measurements should also be possible at ATLAS and CMS. Together, these SoftDrop and FlavorCone studies should clarify a number of aspects of heavy-flavor physics at colliders, and provide crucial information needed to improve heavy-flavor modeling in parton-shower generators.

  19. Coherent bremsstrahlung at colliding beams

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, I.F. (Inst. of Mathematics, Novosibirsk (Russia)); Kotkin, G.L.; Serbo, V.G. (Novosibirsk State Univ. (Russia)); Polityko, S.I. (Irkutsk State Univ. (Russia))

    1992-07-30

    We consider a new type of radiation at colliders with short bunches - coherent bremsstrahlung (CBS). CBS can be treated as radiation of the first bunch particles caused by the collective electromagnetic field of the short second bunch. A general method for the calculation of this CBS is presented. The number of CBS photons per single collision is dN{sub {gamma}}{approx equal}N{sub 0}dE{sub {gamma}}/E{sub {gamma}} in the energy range E{sub {gamma}}colliders VEPP-4M, BEPC, CESR, TRISTAN the quantity N{sub 0}{approx equal}10{sup 8} and E{sub c}{approx equal}1-100 keV. Unusual properties of CBS and the possibility of using CBS for measuring the beam parameters are discussed. (orig.).

  20. Very large hadron collider (VLHC)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    A VLHC informal study group started to come together at Fermilab in the fall of 1995 and at the 1996 Snowmass Study the parameters of this machine took form. The VLHC as now conceived would be a 100 TeV hadron collider. It would use the Fermilab Main Injector (now nearing completion) to inject protons at 150 GeV into a new 3 TeV Booster and then into a superconducting pp collider ring producing 100 TeV c.m. interactions. A luminosity of {approximately}10{sup 34} cm{sup -2}s{sup -1} is planned. Our plans were presented to the Subpanel on the Planning for the Future of US High- Energy Physics (the successor to the Drell committee) and in February 1998 their report stated ``The Subpanel recommends an expanded program of R&D on cost reduction strategies, enabling technologies, and accelerator physics issues for a VLHC. These efforts should be coordinated across laboratory and university groups with the aim of identifying design concepts for an economically and technically viable facility`` The coordination has been started with the inclusion of physicists from Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL), and Cornell University. Clearly, this collaboration must expanded internationally as well as nationally. The phrase ``economically and technically viable facility`` presents the real challenge.

  1. Digital-computer normal shock position and restart control of a Mach 2.5 axisymmetric mixed-compression inlet

    Science.gov (United States)

    Neiner, G. H.; Cole, G. L.; Arpasi, D. J.

    1972-01-01

    Digital computer control of a mixed-compression inlet is discussed. The inlet was terminated with a choked orifice at the compressor face station to dynamically simulate a turbojet engine. Inlet diffuser exit airflow disturbances were used. A digital version of a previously tested analog control system was used for both normal shock and restart control. Digital computer algorithms were derived using z-transform and finite difference methods. Using a sample rate of 1000 samples per second, the digital normal shock and restart controls essentially duplicated the inlet analog computer control results. At a sample rate of 100 samples per second, the control system performed adequately but was less stable.

  2. Tests of the FONT3 Linear Collider Intra-Train Beam Feedback System at the ATF

    CERN Document Server

    Burrows, P N; Clarke, Christine; Frisch, Josef; Hartin, Anthony F; Kalinin, Alexander; Khah, H; Markiewicz, Thomas W; McCormick, Douglas; Molloy, Stephen; Perry, Colin; Ross, Marc; Smith, Stephen; Smith, Tonee; White, Glen

    2005-01-01

    We report preliminary results of beam tests of the FONT3 Linear Collider intra-train position feedback system prototype at the Accelerator Test Facility at KEK. The feedback system incorporates a novel beam position monitor (BPM) processor with a latency below 5 nanoseconds, and a kicker driver amplifier with similar low latency. The 56 nanosecond-long bunchtrain in the ATF extraction line was used to test the prototype with delay-loop feedback operation. The achieved latency represents a demonstration of intra-train feedback on timescales relevant even for the CLIC Linear Collider design.

  3. Last magnet in place for colossal collider

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "Workers have installed the last magnet for the world's mew highest-energy particle smasher, the Large Hadron Collider (LHC). The installation marks an important milestone; however, researchers still may not get the collider completed in time to start it up in November as planned." (1 page)

  4. The Global Future Circular Colliders Effort

    CERN Document Server

    Benedikt, Michael

    2013-01-01

    This presentation has been given during the P5 Workshop at BNL Brookhaven (US). It contains - Global Future Circular Collier Studies Overview and Status - Main challenges and R&D areas for hadron collider - Main challenges and R&D areas for lepton collider - Conclusions

  5. Possible limits of plasma linear colliders

    Science.gov (United States)

    Zimmermann, F.

    2017-07-01

    Plasma linear colliders have been proposed as next or next-next generation energy-frontier machines for high-energy physics. I investigate possible fundamental limits on energy and luminosity of such type of colliders, considering acceleration, multiple scattering off plasma ions, intrabeam scattering, bremsstrahlung, and betatron radiation. The question of energy efficiency is also addressed.

  6. Multibillion-dolalr collider plans unveiled

    CERN Multimedia

    Cartlidge, Edwin

    2007-01-01

    "Particle physicists released an outline design for the proposed International Linear Collider (ILC) at a meeting in Beijing this morning. The design details the components needed to build the 31 km-long facility and comes with and initial estimate of the collider's cost: a cool $6.5bn for the core project. (1 page)

  7. Collide@CERN: sharing inspiration

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    Late last year, Julius von Bismarck was appointed to be CERN's first "artist in residence" after winning the Collide@CERN Digital Arts award. He’ll be spending two months at CERN starting this March but, to get a flavour of what’s in store, he visited the Organization last week for a crash course in its inspiring activities.   Julius von Bismarck, taking a closer look... When we arrive to interview German artist Julius von Bismarck, he’s being given a presentation about antiprotons’ ability to kill cancer cells. The whiteboard in the room contains graphs and equations that might easily send a non-scientist running, yet as Julius puts it, “if I weren’t interested, I’d be asleep”. Given his numerous questions, he must have been fascinated. “This ‘introduction’ week has been exhilarating,” says Julius. “I’ve been able to interact ...

  8. Reconnection of Colliding Cosmic Strings

    CERN Document Server

    Hanany, A; Hanany, Amihay; Hashimoto, Koji

    2005-01-01

    For vortex strings in the Abelian Higgs model and D-strings in superstring theory, both of which can be regarded as cosmic strings, we give analytical study of reconnection (recombination, inter-commutation) when they collide, by using effective field theories on the strings. First, for the vortex strings, via a string sigma model, we verify analytically that the reconnection is classically inevitable for small collision velocity and small relative angle. Evolution of the shape of the reconnected strings provides an upper bound on the collision velocity in order for the reconnection to occur. These analytical results are in agreement with previous numerical results. On the other hand, reconnection of the D-strings is not classical but probabilistic. We show that a quantum calculation of the reconnection probability using a D-string action reproduces the nonperturbative nature of the worldsheet results by Jackson, Jones and Polchinski. The difference on the reconnection -- classically inevitable for the vortex...

  9. Collide@CERN - public lecture

    CERN Multimedia

    2012-01-01

    CERN, the Republic and Canton of Geneva and the City of Geneva are delighted to invite you to a public lecture by Gilles Jobin, first winner of the Collide@CERN Geneva Dance and Performance Artist-in-residence Prize, and his CERN inspiration partner, Joao Pequenao. They will present their work in dance and science at the Globe of Science and Innovation on Wednesday, 23 May 2012 at 7 p.m. (doors open at 6.30 p.m.).   
                                                  Programme 19:00 Opening address by - Professor Rolf-Dieter Heuer, CERN Director-General, - Ariane Koek...

  10. Collider searches for extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Landsberg, Greg; /Brown U.

    2004-12-01

    Searches for extra spatial dimensions remain among the most popular new directions in our quest for physics beyond the Standard Model. High-energy collider experiments of the current decade should be able to find an ultimate answer to the question of their existence in a variety of models. Until the start of the LHC in a few years, the Tevatron will remain the key player in this quest. In this paper, we review the most recent results from the Tevatron on searches for large, TeV{sup -1}-size, and Randall-Sundrum extra spatial dimensions, which have reached a new level of sensitivity and currently probe the parameter space beyond the existing constraints. While no evidence for the existence of extra dimensions has been found so far, an exciting discovery might be just steps away.

  11. A muon collider as a Higgs factory

    CERN Document Server

    Neuffer, D; Alexahin, Y; Ankenbrandt, C; Delahaye, J P

    2015-01-01

    Because muons connect directly to a standard-model Higgs particle in s-channel production, a muon collider would be an ideal device for precision measurement of the mass and width of a Higgs-like particle, and for further exploration of its production and decay properties. Parameters of a high-precision muon collider are presented and the necessary components and performance are described. An important advantage of the muon collider approach is that the spin precession of the muons will enable energy measurements at extremely high accuracy (dE/E to 10-6 or better). The collider could be a first step toward a high-luminosity multi-TeV lepton collider, and extensions toward a higher-energy higher-luminosity device are also discussed.

  12. APPLICATION OF RESTART COVARIANCE MATRIX ADAPTATION EVOLUTION STRATEGY (RCMA-ES TO GENERATION EXPANSION PLANNING PROBLEM

    Directory of Open Access Journals (Sweden)

    K. Karthikeyan

    2012-10-01

    Full Text Available This paper describes the application of an evolutionary algorithm, Restart Covariance Matrix Adaptation Evolution Strategy (RCMA-ES to the Generation Expansion Planning (GEP problem. RCMA-ES is a class of continuous Evolutionary Algorithm (EA derived from the concept of self-adaptation in evolution strategies, which adapts the covariance matrix of a multivariate normal search distribution. The original GEP problem is modified by incorporating Virtual Mapping Procedure (VMP. The GEP problem of a synthetic test systems for 6-year, 14-year and 24-year planning horizons having five types of candidate units is considered. Two different constraint-handling methods are incorporated and impact of each method has been compared. In addition, comparison and validation has also made with dynamic programming method.

  13. Parallelizable restarted iterative methods for nonsymmetric linear systems. Part 1: Theory

    Energy Technology Data Exchange (ETDEWEB)

    Joubert, W.D.; Carey, G.F.

    1991-05-01

    Large sparse nonsymmetric problems of the form Au = b are frequently solved using restarted conjugate gradient-type algorithms such as the popular GCR and GMRES algorithms. In this study the authors define a new class of algorithms which generate the same iterates as the standard GMRES algorithm but require as little as half of the computational expense. This performance improvement is obtained by using short economical three-term recurrences to replace the long recurrence used by GMRES. The new algorithms are shown to have good numerical properties in typical cases, and the new algorithms may be easily modified to be as numerically safe as standard GMRES. Numerical experiments with these algorithms are given in Part 2, in which they demonstrate the improved performance of the new schemes on different computer architectures.

  14. Asynchronous Checkpoint Migration with MRNet in the Scalable Checkpoint / Restart Library

    Energy Technology Data Exchange (ETDEWEB)

    Mohror, K; Moody, A; de Supinski, B R

    2012-03-20

    Applications running on today's supercomputers tolerate failures by periodically saving their state in checkpoint files on stable storage, such as a parallel file system. Although this approach is simple, the overhead of writing the checkpoints can be prohibitive, especially for large-scale jobs. In this paper, we present initial results of an enhancement to our Scalable Checkpoint/Restart Library (SCR). We employ MRNet, a tree-based overlay network library, to transfer checkpoints from the compute nodes to the parallel file system asynchronously. This enhancement increases application efficiency by removing the need for an application to block while checkpoints are transferred to the parallel file system. We show that the integration of SCR with MRNet can reduce the time spent in I/O operations by as much as 15x. However, our experiments exposed new scalability issues with our initial implementation. We discuss the sources of the scalability problems and our plans to address them.

  15. Recombination occurs within minutes of replication blockage by RTS1 producing restarted forks that are prone to collapse

    Science.gov (United States)

    Nguyen, Michael O; Jalan, Manisha; Morrow, Carl A; Osman, Fekret; Whitby, Matthew C

    2015-01-01

    The completion of genome duplication during the cell cycle is threatened by the presence of replication fork barriers (RFBs). Following collision with a RFB, replication proteins can dissociate from the stalled fork (fork collapse) rendering it incapable of further DNA synthesis unless recombination intervenes to restart replication. We use time-lapse microscopy and genetic assays to show that recombination is initiated within ∼10 min of replication fork blockage at a site-specific barrier in fission yeast, leading to a restarted fork within ∼60 min, which is only prevented/curtailed by the arrival of the opposing replication fork. The restarted fork is susceptible to further collapse causing hyper-recombination downstream of the barrier. Surprisingly, in our system fork restart is unnecessary for maintaining cell viability. Seemingly, the risk of failing to complete replication prior to mitosis is sufficient to warrant the induction of recombination even though it can cause deleterious genetic change. DOI: http://dx.doi.org/10.7554/eLife.04539.001 PMID:25806683

  16. Getting to First Flight: Equipping Space Engineers to Break the Start-Stop-Restart Cycle

    Science.gov (United States)

    Singer, Christopher E.; Dumbacher, Daniel L.

    2010-01-01

    The National Aeronautics and Space Administration s (NASA s) history is built on a foundation of can-do strength, while pointing to the Saturn/Apollo Moon missions in the 1960s and 1970s as its apex a sentiment that often overshadows the potential that lies ahead. The chronicle of America s civil space agenda is scattered with programs that got off to good starts with adequate resources and vocal political support but that never made it past a certain milestone review, General Accountability Office report, or Congressional budget appropriation. Over the decades since the fielding of the Space Shuttle in the early 1980s, a start-stop-restart cycle has intervened due to many forces. Despite this impediment, the workforce has delivered engineering feats such as the International Space Station and numerous Shuttle and science missions, which reflect a trend in the early days of the Exploration Age that called for massive infrastructure and matching capital allocations. In the new millennium, the aerospace industry must respond to transforming economic climates, the public will, national agendas, and international possibilities relative to scientific exploration beyond Earth s orbit. Two pressing issues - workforce transition and mission success - are intertwined. As this paper will address, U.S. aerospace must confront related workforce development and industrial base issues head on to take space exploration to the next level. This paper also will formulate specific strategies to equip space engineers to move beyond the seemingly constant start-stop-restart mentality to plan and execute flight projects that actually fly.

  17. RELAP5-3D Resolution of Known Restart/Backup Issues

    Energy Technology Data Exchange (ETDEWEB)

    Mesina, George L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Anderson, Nolan A. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-12-01

    The state-of-the-art nuclear reactor system safety analysis computer program developed at the Idaho National Laboratory (INL), RELAP5-3D, continues to adapt to changes in computer hardware and software and to develop to meet the ever-expanding needs of the nuclear industry. To continue at the forefront, code testing must evolve with both code and industry developments, and it must work correctly. To best ensure this, the processes of Software Verification and Validation (V&V) are applied. Verification compares coding against its documented algorithms and equations and compares its calculations against analytical solutions and the method of manufactured solutions. A form of this, sequential verification, checks code specifications against coding only when originally written then applies regression testing which compares code calculations between consecutive updates or versions on a set of test cases to check that the performance does not change. A sequential verification testing system was specially constructed for RELAP5-3D to both detect errors with extreme accuracy and cover all nuclear-plant-relevant code features. Detection is provided through a “verification file” that records double precision sums of key variables. Coverage is provided by a test suite of input decks that exercise code features and capabilities necessary to model a nuclear power plant. A matrix of test features and short-running cases that exercise them is presented. This testing system is used to test base cases (called null testing) as well as restart and backup cases. It can test RELAP5-3D performance in both standalone and coupled (through PVM to other codes) runs. Application of verification testing revealed numerous restart and backup issues in both standalone and couple modes. This document reports the resolution of these issues.

  18. Optimizing integrated luminosity of future hadron colliders

    Directory of Open Access Journals (Sweden)

    Michael Benedikt

    2015-10-01

    Full Text Available The integrated luminosity, a key figure of merit for any particle-physics collider, is closely linked to the peak luminosity and to the beam lifetime. The instantaneous peak luminosity of a collider is constrained by a number of boundary conditions, such as the available beam current, the maximum beam-beam tune shift with acceptable beam stability and reasonable luminosity lifetime (i.e., the empirical “beam-beam limit”, or the event pileup in the physics detectors. The beam lifetime at high-luminosity hadron colliders is largely determined by particle burn off in the collisions. In future highest-energy circular colliders synchrotron radiation provides a natural damping mechanism, which can be exploited for maximizing the integrated luminosity. In this article, we derive analytical expressions describing the optimized integrated luminosity, the corresponding optimum store length, and the time evolution of relevant beam parameters, without or with radiation damping, while respecting a fixed maximum value for the total beam-beam tune shift or for the event pileup in the detector. Our results are illustrated by examples for the proton-proton luminosity of the existing Large Hadron Collider (LHC at its design parameters, of the High-Luminosity Large Hadron Collider (HL-LHC, and of the Future Circular Collider (FCC-hh.

  19. CERN boss quashes LHC delay rumours

    CERN Multimedia

    2007-01-01

    "Robert Aymar, the director general of CERN, has dispelled rumours that a series of buckled electrical connectors at the Large Hadron Collider will delay the accelerator's official start-up date of May 2008. Writing in this week's CERN Bulletin, Aymar says that the problem concerns only a small percentage of the connectors and that it is "business as usual" for bringing the new accelerator online." (1,5 page)

  20. On the Future High Energy Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir [Fermilab

    2015-09-28

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

  1. Maverick dark matter at colliders

    Science.gov (United States)

    Beltrán, Maria; Hooper, Dan; Kolb, Edward W.; Krusberg, Zosia A. C.; Tait, Tim M. P.

    2010-09-01

    Assuming that dark matter is a weakly interacting massive particle (WIMP) species X produced in the early Universe as a cold thermal relic, we study the collider signal of pp or pbar{p} rightarrow bar{X}X + jets and its distinguishability from standard-model background processes associated with jets and missing energy. We assume that the WIMP is the sole particle related to dark matter within reach of the LHC — a “maverick” particle — and that it couples to quarks through a higher dimensional contact interaction. We simulate the WIMP final-state signal Xbar{X} + jets and dominant standard-model (SM) background processes and find that the dark-matter production process results in higher energies for the colored final state partons than do the standard-model background processes. As a consequence, the detectable signature of maverick dark matter is an excess over standard-model expectations of events consisting of large missing transverse energy, together with large leading jet transverse momentum and scalar sum of the transverse momenta of the jets. Existing Tevatron data and forthcoming LHC data can constrain (or discover!) maverick dark matter.

  2. String Resonances at Hadron Colliders

    CERN Document Server

    Anchordoqui, Luis A; Dai, De-Chang; Feng, Wan-Zhe; Goldberg, Haim; Huang, Xing; Lust, Dieter; Stojkovic, Dejan; Taylor, Tomasz R

    2014-01-01

    [Abridged] We consider extensions of the standard model based on open strings ending on D-branes. Assuming that the fundamental string mass scale M_s is in the TeV range and that the theory is weakly coupled, we discuss possible signals of string physics at the upcoming HL-LHC run (3000 fb^{-1}) with \\sqrt{s} = 14 TeV, and at potential future pp colliders, HE-LHC and VLHC, operating at \\sqrt{s} = 33 and 100 TeV, respectively. In such D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets and \\gamma + jet are completely independent of the details of compactification, and can be evaluated in a parameter-free manner. We make use of these amplitudes evaluated near the first (n=1) and second (n=2) resonant poles to determine the discovery potential for Regge excitations of the quark, the gluon, and the color singlet living on the QCD stack. We show that for string scales as large as 7.1 TeV (6.1 TeV), lowest massive Regge exc...

  3. The Relativistic Heavy Ion Collider

    Science.gov (United States)

    Fischer, Wolfram

    The Relativistic Heavy Ion Collider (RHIC), shown in Fig. 1, was build to study the interactions of quarks and gluons at high energies [Harrison, Ludlam and Ozaki (2003)]. The theory of Quantum Chromodynamics (QCD) describes these interactions. One of the main goals for the RHIC experiments was the creation and study of the Quark-Gluon Plasma (QGP), which was expected to be formed after the collision of heavy ions at a temperature of approximately 2 trillion kelvin (or equivalently an energy of 150 MeV). The QGP is the substance which existed only a few microseconds after the Big Bang. The QGP was anticipated to be weakly interacting like a gas but turned out to be strongly interacting and more like a liquid. Among its unusual properties is its extremely low viscosity [Auerbach and Schlomo (2009)], which makes the QGP the substance closest to a perfect liquid known to date. The QGP is opaque to moderate energy quarks and gluons leading to a phenomenon called jet quenching, where of a jet and its recoil jet only one is observable and the other suppressed after traversing and interacting with the QGP [Jacak and Müller (2012)]...

  4. Physics with $e^{+} e^{-}$ linear colliders

    CERN Document Server

    Behnke, T; Zerwas, Peter M

    2002-01-01

    The physics programme is summarized for future e**+e**- linear colliders. These machines will allow us to perform precision studies of the top quark and the electroweak gauge bosons in a complementary way to the proton collider LHC. The Higgs boson can be discovered at the LHC within the entire range of canonical mass values. Lepton colliders are ideal instruments to investigate the properties of the Higgs boson and to establish essential elements of the Higgs mechanism as the fundamental mechanism for breaking the electroweak symmetries. In the area beyond the Standard Model, new particles and their interactions can be discovered and explored comprehensively. Supersymmetric particles can be searched for at the LHC with masses up to 2-3 TeV. Their properties can be determined at lepton colliders with very high precision so that the mechanism of supersymmetry breaking can be investigated experimentally and the underlying unified theory can be reconstructed. Stable extrapolations are possible up to scales near ...

  5. Physics at Hadronic Colliders (4/4)

    CERN Document Server

    CERN. Geneva

    2008-01-01

    Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)

  6. Physics at Hadronic Colliders (3/4)

    CERN Document Server

    CERN. Geneva

    2008-01-01

    Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)

  7. Physics at Hadronic Colliders (2/4)

    CERN Document Server

    CERN. Geneva

    2008-01-01

    Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)

  8. Physics at Hadronic Colliders (1/4)

    CERN Document Server

    CERN. Geneva

    2008-01-01

    Hadron colliders are often called "discovery machines" since they produce the highest mass particles and thus give often the best chance to discover new high mass particles. Currently they are particularly topical since the Large Hadron Collider will start operating later this year, increasing the centre-of-mass energy by a factor of seven compared to the current highest energy collider, the Tevatron. I will review the benefits and challenges of hadron colliders and review some of the current physics results from the Tevatron and give an outlook to the future results we are hoping for at the LHC. Prerequisite knowledge: Introduction to Particle Physics (F. Close), Detectors (W. Riegler, at least mostly) and The Standard Model (A. Pich)

  9. The collider calamity, publ. by Scientific American

    CERN Multimedia

    2006-01-01

    "For decades, the big guns of American science have been the U.S. Department of Energy's particle collider, which investigate the nature of matter by accelerating subatomic particles and smashing them together." (1 page)

  10. Optimizing integrated luminosity of future hadron colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Schulte, Daniel; Zimmermann, Frank

    2015-01-01

    The integrated luminosity, a key figure of merit for any particle-physics collider, is closely linked to the peak luminosity and to the beam lifetime. The instantaneous peak luminosity of a collider is constrained by a number of boundary conditions, such as the available beam current, the maximum beam-beam tune shift with acceptable beam stability and reasonable luminosity lifetime (i.e., the empirical “beam-beam limit”), or the event pileup in the physics detectors. The beam lifetime at high-luminosity hadron colliders is largely determined by particle burn off in the collisions. In future highest-energy circular colliders synchrotron radiation provides a natural damping mechanism, which can be exploited for maximizing the integrated luminosity. In this article, we derive analytical expressions describing the optimized integrated luminosity, the corresponding optimum store length, and the time evolution of relevant beam parameters, without or with radiation damping, while respecting a fixed maximum value...

  11. Il Collisore LHC (Large Hadron Collider)

    CERN Multimedia

    Brianti, Giorgio

    2004-01-01

    In 2007, in a new Collider in the tunnel of 27km, collisions will be made between very powerful beams of protons and ions. The energies will be very high to try to catch the most tiny particle (1 page)

  12. Physics prospects at a linear + - collider

    Indian Academy of Sciences (India)

    Saurabh D Rindani

    2006-10-01

    The talk described the prospects of studying standard model parameters as well as scenarios beyond the standard model, like the minimal supersymmetric standard model, theories with extra dimensions and theories with extra neutral gauge bosons, at a future linear + - collider.

  13. Facts about real antimatter collide with fiction

    CERN Document Server

    Siegfried, Tom

    2004-01-01

    When science collides with fiction, sometimes a best seller emerges from the debris. Take Dan Brown's Angels & Demons, for instance, a murder mystery based on science at CERN, the European nuclear research laboratory outside Geneva

  14. Final focus systems for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, R.A.

    1987-11-01

    The final focus system of a linear collider must perform two primary functions, it must focus the two opposing beams so that their transverse dimensions at the interaction point are small enough to yield acceptable luminosity, and it must steer the beams together to maintain collisions. In addition, the final focus system must transport the outgoing beams to a location where they can be recycled or safely dumped. Elementary optical considerations for linear collider final focus systems are discussed, followed by chromatic aberrations. The design of the final focus system of the SLAC Linear Collider (SLC) is described. Tuning and diagnostics and steering to collision are discussed. Most of the examples illustrating the concepts covered are drawn from the SLC, but the principles and conclusions are said to be generally applicable to other linear collider designs as well. 26 refs., 17 figs. (LEW)

  15. Nuclear collisions at the Future Circular Collider

    Science.gov (United States)

    Armesto, N.; Dainese, A.; d'Enterria, D.; Masciocchi, S.; Roland, C.; Salgado, C. A.; van Leeuwen, M.; Wiedemann, U. A.

    2016-12-01

    The Future Circular Collider is a new proposed collider at CERN with centre-of-mass energies around 100 TeV in the pp mode. Ongoing studies aim at assessing its physics potential and technical feasibility. Here we focus on updates in physics opportunities accessible in pA and AA collisions not covered in previous Quark Matter contributions, including Quark-Gluon Plasma and gluon saturation studies, novel hard probes of QCD matter, and photon-induced collisions.

  16. Nuclear collisions at the Future Circular Collider

    CERN Document Server

    Armesto, N; d'Enterria, D; Masciocchi, S; Roland, C; Salgado, C A; van Leeuwen, M; Wiedemann, U A

    2016-01-01

    The Future Circular Collider is a new proposed collider at CERN with centre-of-mass energies around 100 TeV in the pp mode. Ongoing studies aim at assessing its physics potential and technical feasibility. Here we focus on updates in physics opportunities accessible in pA and AA collisions not covered in previous Quark Matter contributions, including Quark-Gluon Plasma and gluon saturation studies, novel hard probes of QCD matter, and photon-induced collisions.

  17. Photon Linear Collider Gamma-Gamma Summary

    Energy Technology Data Exchange (ETDEWEB)

    Gronberg, J

    2012-02-27

    High energy photon - photon collisions can be achieved by adding high average power short-pulse lasers to the Linear Collider, enabling an expanded physics program for the facility. The technology required to realize a photon linear collider continues to mature. Compton back-scattering technology is being developed around the world for low energy light source applications and high average power lasers are being developed for Inertial Confinement Fusion.

  18. Academic Training Lecture: Jets at Hadron Colliders

    CERN Multimedia

    PH Department

    2011-01-01

    Regular Programme 30, 31 March and 1 April  2011 from 11:00 to 12:00 -  Bldg. 40-S2-A01 - Salle Andersson Jets at Hadron Colliders by Gavin Salam These three lectures will discuss how jets are defined at hadron colliders, the physics that is responsible for the internal structure of jets and the ways in which an understanding of jets may help in searches for new particles at the LHC.

  19. Final focus designs for crab waist colliders

    Science.gov (United States)

    Bogomyagkov, A.; Levichev, E.; Piminov, P.

    2016-12-01

    The crab waist collision scheme promises significant luminosity gain. The successful upgrade of the DA Φ NE collider proved the principle of crab waist collision and increased luminosity 3 times. Therefore, several new projects try to implement the scheme. The paper reviews interaction region designs with the crab waist collision scheme for already existent collider DA Φ NE and SuperKEKB, presently undergoing commissioning, for the projects of SuperB in Italy, CTau in Novosibirsk and FCC-ee at CERN.

  20. Higgs and SUSY searches at future colliders

    Indian Academy of Sciences (India)

    Rohini M Godbole

    2000-04-01

    In this talk, I discuss some aspects of Higgs searches at future colliders, particularly comparing and contrasting the capabilities of LHC and next linear collider (NLC), including the aspects of Higgs searches in supersymmetric theories. I will also discuss how the search and study of sparticles other than the Higgs can be used to give information about the parameters of the minimal supersymmetric Standard Model (MSSM).

  1. Nuclear collisions at the Future Circular Collider

    Energy Technology Data Exchange (ETDEWEB)

    Armesto, N., E-mail: nestor.armesto@usc.es [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia-Spain (Spain); Dainese, A. [INFN – Sezione di Padova, 35131 Padova (Italy); D' Enterria, D. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland); Masciocchi, S. [EMMI and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Roland, C. [Massachusetts Institute of Technology, Cambridge, MA 02139-4307 (United States); Salgado, C.A. [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia-Spain (Spain); Leeuwen, M. van [Nikhef, National Institute for Subatomic Physics, Amsterdam (Netherlands); Institute for Subatomic Physics of Utrecht University, Utrecht (Netherlands); Wiedemann, U.A. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland)

    2016-12-15

    The Future Circular Collider is a new proposed collider at CERN with centre-of-mass energies around 100 TeV in the pp mode. Ongoing studies aim at assessing its physics potential and technical feasibility. Here we focus on updates in physics opportunities accessible in pA and AA collisions not covered in previous Quark Matter contributions, including Quark-Gluon Plasma and gluon saturation studies, novel hard probes of QCD matter, and photon-induced collisions.

  2. RF pulse compression for future linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, P.B.

    1995-05-01

    Future (nonsuperconducting) linear colliders will require very high values of peak rf power per meter of accelerating structure. The role of rf pulse compression in producing this power is examined within the context of overall rf system design for three future colliders at energies of 1.0--1.5 TeV, 5 TeV and 25 TeV. In order keep the average AC input power and the length of the accelerator within reasonable limits, a collider in the 1.0--1.5 TeV energy range will probably be built at an x-band rf frequency, and will require a peak power on the order of 150--200 MW per meter of accelerating structure. A 5 TeV collider at 34 GHz with a reasonable length (35 km) and AC input power (225 MW) would require about 550 MW per meter of structure. Two-beam accelerators can achieve peak powers of this order by applying dc pulse compression techniques (induction linac modules) to produce the drive beam. Klystron-driven colliders achieve high peak power by a combination of dc pulse compression (modulators) and rf pulse compression, with about the same overall rf system efficiency (30--40%) as a two-beam collider. A high gain (6.8) three-stage binary pulse compression system with high efficiency (80%) is described, which (compared to a SLED-11 system) can be used to reduce the klystron peak power by about a factor of two, or alternately, to cut the number of klystrons in half for a 1.0--1.5 TeV x-band collider. For a 5 TeV klystron-driven collider, a high gain, high efficiency rf pulse compression system is essential.

  3. Considerations on Energy Frontier Colliders after LHC

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir [Fermilab

    2016-11-15

    Since 1960’s, particle colliders have been in the forefront of particle physics, 29 total have been built and operated, 7 are in operation now. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). The future of the world-wide HEP community critically depends on the feasibility of possible post-LHC colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity and feasibility of cost. Here we overview all current options for post-LHC colliders from such perspective (ILC, CLIC, Muon Collider, plasma colliders, CEPC, FCC, HE-LHC) and discuss major challenges and accelerator R&D required to demonstrate feasibility of an energy frontier accelerator facility following the LHC. We conclude by taking a look into ultimate energy reach accelerators based on plasmas and crystals, and discussion on the perspectives for the far future of the accelerator-based particle physics. This paper largely follows previous study [1] and the presenta ion given at the ICHEP’2016 conference in Chicago [2].

  4. LHC Restart 2009 - Accelerating Science - Beam captured just before midnight, November 20th 2009

    CERN Multimedia

    CERN Video Productions

    2009-01-01

    Geneva, 20 November 2009. Particle beams are once again circulating in the world's most powerful particle accelerator, CERN*'s Large Hadron Collider (LHC). This news comes after the machine was handed over for operation on Wednesday morning. A clockwise circulating beam was established at ten o'clock this evening. This is an important milestone on the road towards first physics at the LHC, expected in 2010.

  5. Identifying and Analyzing Novel Epilepsy-Related Genes Using Random Walk with Restart Algorithm

    Directory of Open Access Journals (Sweden)

    Wei Guo

    2017-01-01

    Full Text Available As a pathological condition, epilepsy is caused by abnormal neuronal discharge in brain which will temporarily disrupt the cerebral functions. Epilepsy is a chronic disease which occurs in all ages and would seriously affect patients’ personal lives. Thus, it is highly required to develop effective medicines or instruments to treat the disease. Identifying epilepsy-related genes is essential in order to understand and treat the disease because the corresponding proteins encoded by the epilepsy-related genes are candidates of the potential drug targets. In this study, a pioneering computational workflow was proposed to predict novel epilepsy-related genes using the random walk with restart (RWR algorithm. As reported in the literature RWR algorithm often produces a number of false positive genes, and in this study a permutation test and functional association tests were implemented to filter the genes identified by RWR algorithm, which greatly reduce the number of suspected genes and result in only thirty-three novel epilepsy genes. Finally, these novel genes were analyzed based upon some recently published literatures. Our findings implicate that all novel genes were closely related to epilepsy. It is believed that the proposed workflow can also be applied to identify genes related to other diseases and deepen our understanding of the mechanisms of these diseases.

  6. Efficient two-dimensional magnetotellurics modelling using implicitly restarted Lanczos method

    Indian Academy of Sciences (India)

    Krishna Kumar; Pravin K Gupta; Sri Niwas

    2011-08-01

    This paper presents an efficient algorithm, FDA2DMT (Free Decay Analysis for 2D Magnetotellurics (MT)), based on eigenmode approach to solve the relevant partial differential equation, for forward computation of two-dimensional (2D) responses. The main advantage of this approach lies in the fact that only a small subset of eigenvalues and corresponding eigenvectors are required for satisfactory results. This small subset (pre-specified number) of eigenmodes are obtained using shift and invert implementation of Implicitly Restarted Lanczos Method (IRLM). It has been established by experimentation that only 15–20% smallest eigenvalue and corresponding eigenvectors are sufficient to secure the acceptable accuracy. Once the single frequency response is computed using eigenmode approach, the responses for subsequent frequencies can be obtained in negligible time. Experiment design results for validation of FDA2DMT are presented by considering two synthetic models from COMMEMI report, Brewitt-Taylor and Weaver (1976) model and a field data based model from Garhwal Himalaya.

  7. Identifying and Analyzing Novel Epilepsy-Related Genes Using Random Walk with Restart Algorithm

    Science.gov (United States)

    Guo, Wei; Shang, Dong-Mei; Cao, Jing-Hui; Feng, Kaiyan; Wang, ShaoPeng

    2017-01-01

    As a pathological condition, epilepsy is caused by abnormal neuronal discharge in brain which will temporarily disrupt the cerebral functions. Epilepsy is a chronic disease which occurs in all ages and would seriously affect patients' personal lives. Thus, it is highly required to develop effective medicines or instruments to treat the disease. Identifying epilepsy-related genes is essential in order to understand and treat the disease because the corresponding proteins encoded by the epilepsy-related genes are candidates of the potential drug targets. In this study, a pioneering computational workflow was proposed to predict novel epilepsy-related genes using the random walk with restart (RWR) algorithm. As reported in the literature RWR algorithm often produces a number of false positive genes, and in this study a permutation test and functional association tests were implemented to filter the genes identified by RWR algorithm, which greatly reduce the number of suspected genes and result in only thirty-three novel epilepsy genes. Finally, these novel genes were analyzed based upon some recently published literatures. Our findings implicate that all novel genes were closely related to epilepsy. It is believed that the proposed workflow can also be applied to identify genes related to other diseases and deepen our understanding of the mechanisms of these diseases.

  8. Global Convergence of a New restarting Conjugate Gradient Method for Nonlinear Optimizations

    Institute of Scientific and Technical Information of China (English)

    SUNQing-ying

    2003-01-01

    Conjugate gradient optimization algorithms depend on the search directions.with different choices for the parameters in the search directions.In this note,by combining the nice numerical performance of PR and HS methods with the global convergence property of the class of conjugate gradient methods presented by HU and STOREY(1991),a class of new restarting conjugate gradient methods is presented.Global convergences of the new method with two kinds of common line searches,are proved .Firstly,it is shown that,using reverse modulus of continuity funciton and forcing function,the new method for solving unconstrained optimization can work for a continously differentiable function with Curry-Altman's step size rule and a bounded level set .Secondly,by using comparing technique,some general convergence propecties of the new method with other kind of step size rule are established,Numerical experiments show that the new method is efficient by comparing with FR conjugate gradient method.

  9. Fast parallel MR image reconstruction via B1-based, adaptive restart, iterative soft thresholding algorithms (BARISTA).

    Science.gov (United States)

    Muckley, Matthew J; Noll, Douglas C; Fessler, Jeffrey A

    2015-02-01

    Sparsity-promoting regularization is useful for combining compressed sensing assumptions with parallel MRI for reducing scan time while preserving image quality. Variable splitting algorithms are the current state-of-the-art algorithms for SENSE-type MR image reconstruction with sparsity-promoting regularization. These methods are very general and have been observed to work with almost any regularizer; however, the tuning of associated convergence parameters is a commonly-cited hindrance in their adoption. Conversely, majorize-minimize algorithms based on a single Lipschitz constant have been observed to be slow in shift-variant applications such as SENSE-type MR image reconstruction since the associated Lipschitz constants are loose bounds for the shift-variant behavior. This paper bridges the gap between the Lipschitz constant and the shift-variant aspects of SENSE-type MR imaging by introducing majorizing matrices in the range of the regularizer matrix. The proposed majorize-minimize methods (called BARISTA) converge faster than state-of-the-art variable splitting algorithms when combined with momentum acceleration and adaptive momentum restarting. Furthermore, the tuning parameters associated with the proposed methods are unitless convergence tolerances that are easier to choose than the constraint penalty parameters required by variable splitting algorithms.

  10. DNA replication restart and cellular dynamics of Hef helicase/nuclease protein in Haloferax volcanii.

    Science.gov (United States)

    Lestini, Roxane; Delpech, Floriane; Myllykallio, Hannu

    2015-11-01

    Understanding how frequently spontaneous replication arrests occur and how archaea deal with these arrests are very interesting and challenging research topics. Here we will described how genetic and imaging studies have revealed the central role of the archaeal helicase/nuclease Hef belonging to the XPF/MUS81/FANCM family of endonucleases in repair of arrested replication forks. Special focus will be on description of a recently developed combination of genetic and imaging tools to study the dynamic localization of a functional Hef::GFP (Green Fluorescent Protein) fusion protein in the living cells of halophilic archaea Haloferax volcanii. As Archaea provide an excellent and unique model for understanding how DNA replication is regulated to allow replication of a circular DNA molecule either from single or multiple replication origins, we will also summarize recent studies that have revealed peculiar features regarding DNA replication, particularly in halophilic archaea. We strongly believe that fundamental knowledge of our on-going studies will shed light on the evolutionary history of the DNA replication machinery and will help to establish general rules concerning replication restart and the key role of recombination proteins not only in bacteria, yeast and higher eukaryotes but also in archaea.

  11. PROSPECTS FOR COLLIDERS AND COLLIDER PHYSICS TO THE 1 PEV ENERGY SCALE

    Energy Technology Data Exchange (ETDEWEB)

    KING,B.J.

    2000-05-05

    A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing the authors progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC--one each of e{sup +}e{sup {minus}} and hadron colliders and three {mu}{sup +}{mu}{sup {minus}} colliders--and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R and D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory.

  12. The Superconducting Super Collider: A status report

    Energy Technology Data Exchange (ETDEWEB)

    Schwitters, R.F.

    1993-04-01

    The design of the Superconducting Super Collider (SSC) is briefly reviewed, including its key machine parameters. The scientific objectives are twofold: (1) investigation of high-mass, low-rate, rare phenomena beyond the standard model; and (2) investigation of processes within the domain of the standard model. Machine luminosity, a key parameter, is a function of beam brightness and current, and it must be preserved through the injector chain. Features of the various injectors are discussed. The superconducting magnet system is reviewed in terms of model magnet performance, including the highly successful Accelerator System String Test Various magnet design modifications are noted, reflecting minor changes in the collider arcs and improved installation procedures. The paper concludes with construction scenarios and priority issues for ensuring the earliest collider commissioning.

  13. Electron lenses for super-colliders

    CERN Document Server

    Shiltsev, Vladimir D

    2016-01-01

    This book provides a comprehensive overview of the operating principles and technology of electron lenses in supercolliders.  Electron lenses are a novel instrument for high energy particle accelerators, particularly for the energy-frontier superconducting hadron colliders, including the Tevatron, RHIC, LHC and future very large hadron colliders.  After reviewing the issues surrounding beam dynamics in supercolliders, the book offers an introduction to the electron lens method and its application.  Further chapters describe the technology behind the electron lenses which have recently been proposed, built and employed for compensation of beam-beam effects and for collimation of high-energy high-intensity beams, for compensation of space-charge effects and several other applications in accelerators. The book will be an invaluable resource for those involved in the design, construction and operation of the next generation of hadron colliders.

  14. Collider and Detector Protection at Beam Accidents

    Science.gov (United States)

    Rakhno, I. L.; Mokhov, N. V.; Drozhdin, A. I.

    2003-12-01

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occured at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section.

  15. Final Cooling for a Muon Collider

    Energy Technology Data Exchange (ETDEWEB)

    Acosta Castillo, John Gabriel [Univ. of Mississippi, Oxford, MS (United States)

    2017-05-01

    To explore the new energy frontier, a new generation of particle accelerators is needed. Muon colliders are a promising alternative, if muon cooling can be made to work. Muons are 200 times heavier than electrons, so they produce less synchrotron radiation, and they behave like point particles. However, they have a short lifetime of 2.2 $\\mathrm{\\mu s}$ and the beam is more difficult to cool than an electron beam. The Muon Accelerator Program (MAP) was created to develop concepts and technologies required by a muon collider. An important effort has been made in the program to design and optimize a muon beam cooling system. The goal is to achieve the small beam emittance required by a muon collider. This work explores a final ionization cooling system using magnetic quadrupole lattices with a low enough $\\beta^{\\star} $ region to cool the beam to the required limit with available low Z absorbers.

  16. 2009 Linear Collider Workshop of the Americas

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Sally [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy

    2009-09-29

    The 2009 Linear Collider Workshop of the Americas was held on the campus of the University of New Mexico from 29 September to 3 October, 2009. This was a joint meeting of the American Linear Collider Physics Group and the ILC Global Design Effort. Two hundred fifty people attended. The number of scientific contributions was 333. The complete agenda, with links to all of the presentations, is available at physics.unm.edu/LCWA09/. The meeting brought together international experts as well as junior scientists, to discuss the physics potential of the linear collider and advances in detector technology. The validation of detector designs was announced, and the detector design groups planned the next phase of the effort. Detector R&D teams reported on progress on many topics including calorimetry and tracking. Recent accelerator design considerations were discussed in a special session for experimentalists and theorists.

  17. International linear collider reference design report

    Energy Technology Data Exchange (ETDEWEB)

    Aarons, G.

    2007-06-22

    The International Linear Collider will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. A proposed electron-positron collider, the ILC will complement the Large Hadron Collider, a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, together unlocking some of the deepest mysteries in the universe. With LHC discoveries pointing the way, the ILC -- a true precision machine -- will provide the missing pieces of the puzzle. Consisting of two linear accelerators that face each other, the ILC will hurl some 10 billion electrons and their anti-particles, positrons, toward each other at nearly the speed of light. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they smash in a blazing crossfire at the centre of the machine. Stretching approximately 35 kilometres in length, the beams collide 14,000 times every second at extremely high energies -- 500 billion-electron-volts (GeV). Each spectacular collision creates an array of new particles that could answer some of the most fundamental questions of all time. The current baseline design allows for an upgrade to a 50-kilometre, 1 trillion-electron-volt (TeV) machine during the second stage of the project. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R&D program, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade.

  18. The Next Linear Collider: NLC2001

    Energy Technology Data Exchange (ETDEWEB)

    D. Burke et al.

    2002-01-14

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider. A first Zeroth-Order Design Report (ZDR) [2] for a second-generation electron-positron linear collider, the Next Linear Collider (NLC), was published five years ago. The NLC design is based on a high-frequency room-temperature rf accelerator. Its goal is exploration of elementary particle physics at the TeV center-of-mass energy, while learning how to design and build colliders at still higher energies. Many advances in accelerator technologies and improvements in the design of the NLC have been made since 1996. This Report is a brief update of the ZDR.

  19. Intercellular signaling via cyclic GMP diffusion through gap junctions restarts meiosis in mouse ovarian follicles.

    Science.gov (United States)

    Shuhaibar, Leia C; Egbert, Jeremy R; Norris, Rachael P; Lampe, Paul D; Nikolaev, Viacheslav O; Thunemann, Martin; Wen, Lai; Feil, Robert; Jaffe, Laurinda A

    2015-04-28

    Meiosis in mammalian oocytes is paused until luteinizing hormone (LH) activates receptors in the mural granulosa cells of the ovarian follicle. Prior work has established the central role of cyclic GMP (cGMP) from the granulosa cells in maintaining meiotic arrest, but it is not clear how binding of LH to receptors that are located up to 10 cell layers away from the oocyte lowers oocyte cGMP and restarts meiosis. Here, by visualizing intercellular trafficking of cGMP in real-time in live follicles from mice expressing a FRET sensor, we show that diffusion of cGMP through gap junctions is responsible not only for maintaining meiotic arrest, but also for rapid transmission of the signal that reinitiates meiosis from the follicle surface to the oocyte. Before LH exposure, the cGMP concentration throughout the follicle is at a uniformly high level of ∼2-4 μM. Then, within 1 min of LH application, cGMP begins to decrease in the peripheral granulosa cells. As a consequence, cGMP from the oocyte diffuses into the sink provided by the large granulosa cell volume, such that by 20 min the cGMP concentration in the follicle is uniformly low, ∼100 nM. The decrease in cGMP in the oocyte relieves the inhibition of the meiotic cell cycle. This direct demonstration that a physiological signal initiated by a stimulus in one region of an intact tissue can travel across many layers of cells via cyclic nucleotide diffusion through gap junctions could provide a general mechanism for diverse cellular processes.

  20. Intercellular signaling via cyclic GMP diffusion through gap junctions restarts meiosis in mouse ovarian follicles

    Science.gov (United States)

    Shuhaibar, Leia C.; Egbert, Jeremy R.; Norris, Rachael P.; Lampe, Paul D.; Nikolaev, Viacheslav O.; Thunemann, Martin; Wen, Lai; Feil, Robert; Jaffe, Laurinda A.

    2015-01-01

    Meiosis in mammalian oocytes is paused until luteinizing hormone (LH) activates receptors in the mural granulosa cells of the ovarian follicle. Prior work has established the central role of cyclic GMP (cGMP) from the granulosa cells in maintaining meiotic arrest, but it is not clear how binding of LH to receptors that are located up to 10 cell layers away from the oocyte lowers oocyte cGMP and restarts meiosis. Here, by visualizing intercellular trafficking of cGMP in real-time in live follicles from mice expressing a FRET sensor, we show that diffusion of cGMP through gap junctions is responsible not only for maintaining meiotic arrest, but also for rapid transmission of the signal that reinitiates meiosis from the follicle surface to the oocyte. Before LH exposure, the cGMP concentration throughout the follicle is at a uniformly high level of ∼2–4 μM. Then, within 1 min of LH application, cGMP begins to decrease in the peripheral granulosa cells. As a consequence, cGMP from the oocyte diffuses into the sink provided by the large granulosa cell volume, such that by 20 min the cGMP concentration in the follicle is uniformly low, ∼100 nM. The decrease in cGMP in the oocyte relieves the inhibition of the meiotic cell cycle. This direct demonstration that a physiological signal initiated by a stimulus in one region of an intact tissue can travel across many layers of cells via cyclic nucleotide diffusion through gap junctions could provide a general mechanism for diverse cellular processes. PMID:25775542

  1. Exotic leptons at future linear colliders

    CERN Document Server

    Biondini, S

    2014-01-01

    Doubly charged excited leptons determine a possible signature for physics beyond the standard model at the present Large Hadron Collider. These exotic states are introduced in extended isospin multiplets and they can be treated either within gauge or contact effective interactions or a mixture of those. In this paper we study the production and the corresponding signatures of doubly charged leptons at the forthcoming linear colliders and we focus on the electron-electron beam setting. In the framework of gauge interactions, the interference between the $t$ and $u$ channel is evaluated that has been neglected so far. A pure leptonic final state is considered ($e^{-} \\, e^{-} \\rightarrow e^{-} \\, e^{-} \\, \

  2. Physics Beyond the Standard Model at Colliders

    Science.gov (United States)

    Matchev, Konstantin

    These lectures introduce the modern machinery used in searches and studies of new physics Beyond the Standard Model (BSM) at colliders. The first lecture provides an overview of the main simulation tools used in high energy physics, including automated parton-level calculators, general purpose event generators, detector simulators, etc. The second lecture is a brief introduction to low energy supersymmetry (SUSY) as a representative BSM paradigm. The third lecture discusses the main collider signatures of SUSY and methods for measuring the masses of new particles in events with missing energy.

  3. Photon collider beam simulation with CAIN

    Indian Academy of Sciences (India)

    Aleksander Filip Żarnecki

    2007-11-01

    The CAIN simulation program was used to study the outgoing beam profile for the photon collider at ILC. The main aim of the analysis was to verify the feasibility of the photon linear collider running with 20 mrad electron beam crossing angle. The main problem is the distorted electron beam, which has to be removed from the interaction region. It is shown that with a new design of the final dipole, it should be possible to avoid large energy losses at the face of the magnet.

  4. Sixth international workshop on linear colliders. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Urakawa, Junji [ed.

    1995-08-01

    The sixth international workshop on linear colliders (LC95) was held by KEK at Tsukuba Center for Institute. In the workshop 8 parallel working group were organized: WG1 (beam sources and injection linacs), WG2 (damping rings and bunch compressors), WG3 (a: RF sources and structures, b: superconducting cavities, c: two beam accelerators), WG4 (beam dynamics in main linacs), WG5 (final focus and integration regions), WG6 (beam instrumentation), WG7 (overall parameters and construction techniques), WG8 (gamma-gamma collider and miscellaneous). This issue compiles materials which were used in the workshop. (J.P.N.).

  5. Precision Physics at the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Heuer, R.-D. [Institut fuer Experimentalphysik, Hamburg University, Hamburg (Germany)

    2006-10-15

    Despite the great success of the Standard Model, many key questions in particle physics and cosmology are unanswered today. Together with the Large Hadron Collider LHC, starting in 2007, the International Linear Collider ILC as the next project planned at the high energy frontier, will play a crucial role in tackling many of these most exciting questions. The high precision achievable with experiments at the ILC will be indispensable in order to reach definite conclusions about many features of new physics expected at the TeV scale. This contribution presents prominent physics examples and describes detector challenges and the project status.

  6. SUSY CP phases and asymmetries at colliders

    CERN Document Server

    Kittel, Olaf

    2009-01-01

    In the Minimal Supersymmetric Standard Model, physical phases of complex parameters lead to CP violation. We show how triple products of particle momenta or spins can be used to construct asymmetries, that allow us to probe these CP phases. To give specific examples, we discuss the production of neutralinos at the International Linear Collider. For the Large Hadron Collider, we discuss CP asymmetries in squark decays, and in the tri-lepton signal. We find that the CP asymmetries can be as large as 60%.

  7. SUSY CP phases and asymmetries at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Kittel, Olaf, E-mail: kittel@ugr.e [Departamento de Fisica Teorica y del Cosmos and CAFPE, Universidad de Granada, E-18071 Granada (Spain)

    2009-06-01

    In the Minimal Supersymmetric Standard Model, physical phases of complex parameters lead to CP violation. We show how triple products of particle momenta or spins can be used to construct asymmetries, that allow us to probe these CP phases. To give specific examples, we discuss the production of neutralinos at the International Linear Collider (ILC). For the Large Hadron Collider (LHC), we discuss CP asymmetries in squark decays, and in the tri-lepton signal. We find that the CP asymmetries can be as large as 60%.

  8. Beam instrumentation for the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Ronald S.; Jansson, Andreas; Shiltsev, Vladimir; /Fermilab

    2009-10-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches and many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for future colliders.

  9. Final focus designs for crab waist colliders

    CERN Document Server

    AUTHOR|(CDS)2084369; Levichev, Evgeny; Piminov, Pavel

    2016-01-01

    The crab waist collision scheme promises significant luminosity gain. The successful upgrade of the DA$\\Phi$NE collider proved the principle of crab waist collision and increased luminosity 3 times. Therefore, several new projects try to implement the scheme. The paper reviews interaction region designs with the crab waist collision scheme for already existent collider DA$\\Phi$NE and SuperKEKB, presently undergoing commissioning, for the projects of SuperB in Italy, CTau in Novosibirsk and FCC-ee at CERN.

  10. Top quark studies at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Sinervo, P.K. [Univ. of Toronto, Ontario (Canada)

    1997-01-01

    The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.

  11. Senate baulks at cost of collider project

    CERN Multimedia

    MacIlwain, C

    1999-01-01

    The US Senate has called for NLC research costs to be cut from 14 to 6 million dollars next year. The intention is to end funding altogether in two years after a report showed that the collider would cost the USA about 5 billion dollars (1 page).

  12. From the LHC to Future Colliders

    DEFF Research Database (Denmark)

    De Roeck, A.; Ellis, J.; Grojean, C.

    2010-01-01

    upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10/fb of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because...

  13. The DELPHI detector at CERN's LEP collider

    CERN Multimedia

    1998-01-01

    DELPHI (DEtector with Lepton, Photon and Hadron Identification), is a detector for e+e- physics, with special emphasis on powerful particle identification , three-dimensional information, high granularity and precise vertex determination. It is installed at LEP (Large Electron and Positron collider) at CERN where it has operated since 1989.

  14. Introduction to quantum chromodynamics at hadron colliders

    Indian Academy of Sciences (India)

    William B Kilgore

    2011-05-01

    A basic introduction to the application of QCD at hadron colliders is presented. I briefly review the phenomenological and theoretical origins of QCD, and then discuss factorization and infrared safety, parton distributions, the computation of hard scattering amplitudes and applications of perturbative QCD.

  15. Plans for 40 km linear collider unveiled

    CERN Multimedia

    Cartlidge, Edwin

    2006-01-01

    Particle physicists have released their first tentative design for the International Linear Collider (ILC), a multibillin dollar accelerator that could switch on by the middle of the next decade. The plans also state that the machine should be built in two underground tunnels even though it would be much cheaper to use just one (1 page)

  16. Colliding waves in metric-affine gravity

    CERN Document Server

    García, A; Macías, A; Mielke, E W; Socorro, J; García, Alberto; Lämmerzahl, Claus; Macías, Alfredo; Mielke, Eckehard W.; Socorro, José

    1998-01-01

    We generalize the formulation of the colliding gravitational waves to metric-affine theories and present an example of such kind of exact solutions. The plane waves are equipped with five symmetries and the resulting geometry after the collision possesses two spacelike Killing vectors.

  17. From the LHC to Future Colliders

    Energy Technology Data Exchange (ETDEWEB)

    De Roeck, A.; Ellis, J.; /CERN; Grojean, C.; Heinemeyer, S.; /Cantabria Inst. of Phys.; Jakobs, K.; /Freiburg U.; Weiglein, G.; /Durham U., IPPP; Azuelos, G.; /TRIUMF; Dawson, S.; /Brookhaven; Gripaios, B.; /CERN; Han, T.; /Wisconsin U., Madison; Hewett, J.; /SLAC; Lancaster, M.; /University Coll. London; Mariotti, C.; /INFN, Turin; Moortgat, F.; /Zurich, ETH; Moortgat-Pick, G.; /Durham U., IPPP; Polesello, G.; /INFN, Pavia; Riemann, S.; /DESY; Assamagan, K.; /Brookhaven; Bechtle, P.; /DESY; Carena, M.; /Fermilab; Chachamis, G.; /PSI, Villigen /Taiwan, Natl. Taiwan U. /INFN, Florence /Bonn U. /CERN /Bonn U. /Freiburg U. /Oxford U. /Louvain U., CP3 /Bangalore, Indian Inst. Sci. /INFN, Milan Bicocca /Munich, Max Planck Inst. /Taiwan, Natl. Taiwan U. /Frascati /Fermilab /Warsaw U. /Florida U. /Orsay, LAL /LPSC, Grenoble /Warsaw U. /Yale U. /Stockholm U., Math. Dept. /Durham U., IPPP /DESY /Rome U. /University Coll. London /UC, San Diego /Heidelberg U. /Florida State U. /SLAC /Durham U., IPPP /Southern Denmark U., CP3-Origins /McGill U. /Durham U., IPPP; /more authors..

    2010-06-11

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300 fb{sup -1} of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10 fb{sup -1} of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, theWorking Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions.

  18. Timeline for particle collider in doubt

    CERN Multimedia

    Klapper, Bradley S

    2007-01-01

    "The world's most ambitious particle collider - which scientists hope could reveal what matter is made of - might not be fully functional until next year, months after its scheduled startup date, officiels at the European Organization for Nuclear Reserach said Thursday." (1 page)

  19. Physics Case for the International Linear Collider

    CERN Document Server

    Fujii, Keisuke; Peskin, Michael E; Barklow, Tim; Gao, Yuanning; Kanemura, Shinya; Kim, Hyungdo; List, Jenny; Nojiri, Mihoko; Perelstein, Maxim; Poeschl, Roman; Reuter, Juergen; Simon, Frank; Tanabe, Tomohiko; Yu, Jaehoon; Wells, James D; Murayama, Hitoshi; Yamamoto, Hitoshi

    2015-01-01

    We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.

  20. Particle collider magnet self-destructs

    CERN Multimedia

    Higgins, Alexander G

    2007-01-01

    "A 43-foot-long magnet for the world's largest particle collider broke "with a loud band and a cloud of dust" during a high-pressure test, and officils said Tuesday they are working to find a replacement part." (1 page)

  1. Status of the Future Circular Collider Study

    CERN Document Server

    Benedikt, Michael

    2016-01-01

    Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute. Its main purpose and long-term goal is to design an energyfrontier hadron collider (FCC-hh) with a centre-of-mass energy of about 100 TeV in a new 80–100 km tunnel. The FCC study also includes the design of a 90–350 GeV highluminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines are being assessed and concepts for experiments will be developed by the end of 2018, in time for the next update of the European Strategy for Particle Physics. This overview summarizes the status of machine designs and parameters, and it discusses the essential technical components being developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets wit...

  2. Linear Collider partners woo newly opened India

    CERN Multimedia

    Bagla, Pallava

    2006-01-01

    "With the wheels of Air Force One barely off the tarmac following U.S. President George W. Bush's visit, which ended India's 3 decades as a nuclear pariah state, a delegation of U.S. and European physicists arrived here last week to discuss India's involvement in the International Linear Collider."

  3. Black Holes and the Large Hadron Collider

    Science.gov (United States)

    Roy, Arunava

    2011-01-01

    The European Center for Nuclear Research or CERN's Large Hadron Collider (LHC) has caught our attention partly due to the film "Angels and Demons." In the movie, an antimatter bomb attack on the Vatican is foiled by the protagonist. Perhaps just as controversial is the formation of mini black holes (BHs). Recently, the American Physical Society…

  4. Working group report: Collider and flavour physics

    Indian Academy of Sciences (India)

    Debajyoti Choudhury; Asesh K Datta; Anirban Kundu

    2009-01-01

    The activities of the working group took place under two broad subgroups: Collider Physics subgroup and Flavour Physics subgroup. Reports on some of the projects undertaken are included. Also, some of the leading discussions organized by the working group are summarized.

  5. Beam-beam issues in asymmetric colliders

    Energy Technology Data Exchange (ETDEWEB)

    Furman, M.A.

    1992-07-01

    We discuss generic beam-beam issues for proposed asymmetric e{sup +}- e{sup -} colliders. We illustrate the issues by choosing, as examples, the proposals by Cornell University (CESR-B), KEK, and SLAC/LBL/LLNL (PEP-II).

  6. Testing supersymmetry at the next linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Feng, J.L.

    1994-09-01

    If new particles are discovered, it will be important to determine if they are the supersymmetric partners of standard model bosons and fermions. Supersymmetry predicts relations among the couplings and masses of these particles. The authors discuss the prospects for testing these relations at a future e{sup +}e{sup {minus}} linear collider with measurements that exploit the availability of polarized beams.

  7. Dreams collide with reality for international experiment

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "Three weeks ago, an international team released a design and cost estimate for the International Linear Collider (ILC). American physicists want to build the ILC at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, and researchers had hoped to break ground in 2012 and fire up the ILC's beams of electrons and positrons in 2019." (1 page)

  8. New physics with the Compact Linear Collider

    CERN Multimedia

    Ellis, Jonathan Richard

    2001-01-01

    Investigating the 'strong' interactions between particles would be best investigated using a lepton-antilepton collider of energy 2 TeV or more. Plans for an accelerator of this type, called CLIC, have been underway at CERN for many years in collaboration with other accelerator laboratories (5 pages).

  9. Black Holes and the Large Hadron Collider

    Science.gov (United States)

    Roy, Arunava

    2011-01-01

    The European Center for Nuclear Research or CERN's Large Hadron Collider (LHC) has caught our attention partly due to the film "Angels and Demons." In the movie, an antimatter bomb attack on the Vatican is foiled by the protagonist. Perhaps just as controversial is the formation of mini black holes (BHs). Recently, the American Physical Society…

  10. Collider Tests of (Composite) Diphoton Resonances

    DEFF Research Database (Denmark)

    Molinaro, Emiliano; Sannino, Francesco; Vignaroli, Natascia

    2016-01-01

    We analyze the Large Hadron Collider sensitivity to new pseudoscalar resonances decaying into diphoton with masses up to scales of few TeVs. We focus on minimal scenarios where the production mechanisms involve either photon or top-mediated gluon fusion, partially motivated by the tantalizing...

  11. Beam dynamics issues for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, R.D.

    1987-09-01

    In this paper we discuss various beam dynamics issues for linear colliders. The emphasis is to explore beam dynamics effects which lead to an effective dilution of the emittance of the beam and thus to a loss of luminosity. These considerations lead to various tolerances which are evaluated for a particular parameter set.

  12. Emotions run high in race for collider

    CERN Multimedia

    Cartlidge, E

    2001-01-01

    The head of KEK expressed his dismay that SLAC has entered into a collaboration with 3 other US labs and proposes to build the next linear collider at Fermilab, Ilinois. KEK wants the next accelerator to be built somewhere in the Asian Pacific region (1 page).

  13. Recent results from proton-antiproton colliders

    Energy Technology Data Exchange (ETDEWEB)

    Geer, S. (Harvard Univ., Cambridge, MA (USA). High Energy Physics Lab.)

    1990-03-01

    New results from the CERN and Fermilab proton-antiproton colliders are summarised. The areas covered are jet physics, direct photon production, W and Z production and decay, heavy flavor production, the search for the top quark, and the search for more exotic phenomena. 46 refs., 20 figs., 4 tabs.

  14. QCD Interconnection Studies at Linear Colliders

    CERN Document Server

    Khoze, V A; Khoze, Valery A.; Sjöstrand, Torbjörn

    1999-01-01

    Heavy objects like the W, Z and t are short-lived compared with typical hadronization times. When pairs of such particles are produced, the subsequent hadronic decay systems may therefore become interconnected. We study such potential effects at Linear Collider energies.

  15. Challenges for highest energy circular colliders

    CERN Document Server

    Benedikt, M; Wenninger, J; Zimmermann, F

    2014-01-01

    A new tunnel of 80–100 km circumference could host a 100 TeV centre-of-mass energy-frontier proton collider (FCC-hh/VHE-LHC), with a circular lepton collider (FCCee/TLEP) as potential intermediate step, and a leptonhadron collider (FCC-he) as additional option. FCC-ee, operating at four different energies for precision physics of the Z, W, and Higgs boson and the top quark, represents a significant push in terms of technology and design parameters. Pertinent R&D efforts include the RF system, topup injection scheme, optics design for arcs and final focus, effects of beamstrahlung, beam polarization, energy calibration, and power consumption. FCC-hh faces other challenges, such as high-field magnet design, machine protection and effective handling of large synchrotron radiation power in a superconducting machine. All these issues are being addressed by a global FCC collaboration. A parallel design study in China prepares for a similar, but smaller collider, called CepC/SppC.

  16. Future Accelerators, Muon Colliders, and Neutrino Factories

    Energy Technology Data Exchange (ETDEWEB)

    Richard A Carrigan, Jr.

    2001-12-19

    Particle physics is driven by five great topics. Neutrino oscillations and masses are now at the fore. The standard model with extensions to supersymmetry and a Higgs to generate mass explains much of the field. The origins of CP violation are not understood. The possibility of extra dimensions has raised tantalizing new questions. A fifth topic lurking in the background is the possibility of something totally different. Many of the questions raised by these topics require powerful new accelerators. It is not an overstatement to say that for some of the issues, the accelerator is almost the experiment. Indeed some of the questions require machines beyond our present capability. As this volume attests, there are parts of the particle physics program that have been significantly advanced without the use of accelerators such as the subject of neutrino oscillations and many aspects of the particle-cosmology interface. At this stage in the development of physics, both approaches are needed and important. This chapter first reviews the status of the great accelerator facilities now in operation or coming on within the decade. Next, midrange possibilities are discussed including linear colliders with the adjunct possibility of gamma-gamma colliders, muon colliders, with precursor neutrino factories, and very large hadron colliders. Finally visionary possibilities are considered including plasma and laser accelerators.

  17. From the LHC to future colliders

    Energy Technology Data Exchange (ETDEWEB)

    De Roeck, A.; Assamagan, K.; Ellis, J.; Grojean, C.; Heinemeyer, S.; Jakobs, K.; Weiglien, G.; Well, J.; Azuelos, G.; Dawson, S.; Gripaios, B.; Han, T.; Hewett, J.; Lancaster, M.; Mariotti, C.; Moortgat, F.; Moortgat-Pick, G.; Polesello, G.; Riemann, S.; Schumacher, M.; Bechtle, P.; Carena, M.; Chachamis, G.; Chen, K.F.; De Curtis, S.; Desch, K.; Dittmar, M.; Dreiner, H.; Duhrssen, M.; Foster, B.; Frandsen, M.T.; Giammanco, A.; Godbole, R.; Gopalakrishna, S.; Govoni, P.; Gunion, J.; Hollik, W.; Hou, W.S.; Isidori, G.; Juste, A.; Kalinowski, J.; Korytov, A.; Kou, E.; Kraml, S.; Krawczyk, M.; Martin, A.; Milstead, D.; Morton-Thurtle, V.; Moenig, K.; Mele, B.; Ozcan, E.; Pieri, M.; Plehn, T.; Reina, L.; Richter-Was, E.; Rizzo, T.; Rolbiecki, K.; Sannino, F.; Schram, M.; Smillie, J.; Sultansoy, S.; Tattersall, J.; Uwer, P., Webber, B.; and Wienemann, P.

    2010-03-02

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300 fb{sup -1} of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10 fb{sup -1} of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, the Working Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions.

  18. Physics Case for the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Keisuke; /KEK, Tsukuba; Grojean, Christophe; /DESY /ICREA, Barcelona; Peskin, Michael E.; Barklow, Tim; /SLAC; Gao, Yuanning; /Tsinghua U., Beijing, CHEP; Kanemura, Shinya; /Toyama U.; Kim, Hyungdo; /Seoul Natl U.; List, Jenny; /DESY; Nojiri, Mihoko; /KEK, Tsukuba; Perelstein, Maxim; /Cornell U., LEPP; Poeschl, Roman; /LAL, Orsay; Reuter, Juergen; /DESY; Simon, Frank; /Munich, Max Planck Inst.; Tanabe, Tomohiko; /Tokyo U., ICEPP; Yu, Jaehoon; /Texas U., Arlington; Wells, James D.; /Michigan U., MCTP; Murayama, Hitoshi; /UC, Berkeley /LBNL /Tokyo U., IPMU; Yamamoto, Hitoshi; /Tohoku U.

    2015-06-23

    We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.

  19. Ultimate parameters of the photon collider at the international linear collider

    Indian Academy of Sciences (India)

    V I Telnov

    2007-12-01

    At linear colliders, the + - luminosity is limited by beam-collision effects, which determine the required emittances of beams in damping rings (DRs). In collisions at the photon collider, these effects are absent, and so smaller emittances are desirable. In the present damping ring designs, nominal DR parameters correspond to those required for + - collisions. In this note, I would like to stress once again that as soon as we plan the photon collider mode of ILC operation, the damping ring emittances are dictated by the photon collider requirements - namely, they should be as small as possible. This can be achieved by adding more wigglers to the DRs; the incremental cost is easily justified by a considerable potential improvement of the luminosity. No expert analysis exists as of now, but it seems realistic to obtain a factor five increase of the luminosity compared to the `nominal' DR design.

  20. The lay-out of the photon collider at the international linear collider

    Indian Academy of Sciences (India)

    V I Telnov

    2007-12-01

    One of the interaction regions at the linear colliders should be compatible both with + - and , modes of operation. In this paper, the differences in requirements and possible design solutions are discussed.

  1. A new jet reconstruction algorithm for lepton colliders

    CERN Document Server

    Boronat, Marça; Vos, Marcel

    2014-01-01

    We propose a new sequential jet reconstruction algorithm for future lepton colliders at the energy frontier. The Valencia algorithm combines the natural distance criterion for lepton colliders with the greater robustness against backgrounds of algorithms adapted to hadron colliders. Results on a detailed Monte Carlo simulation of $t\\bar{t}$ and $ZZ$ production at future linear $e^+e^-$ colliders (ILC and CLIC) with a realistic level of background overlaid, show that it achieves better performance in the presence of background.

  2. Direct versus Indirect Treatment for Preschool Children who Stutter: The RESTART Randomized Trial.

    Directory of Open Access Journals (Sweden)

    Caroline de Sonneville-Koedoot

    Full Text Available Stuttering is a common childhood disorder. There is limited high quality evidence regarding options for best treatment. The aim of the study was to compare the effectiveness of direct treatment with indirect treatment in preschool children who stutter.In this multicenter randomized controlled trial with an 18 month follow-up, preschool children who stutter who were referred for treatment were randomized to direct treatment (Lidcombe Program; n = 99 or indirect treatment (RESTART-DCM treatment; n = 100. Main inclusion criteria were age 3-6 years, ≥3% syllables stuttered (%SS, and time since onset ≥6 months. The primary outcome was the percentage of non-stuttering children at 18 months. Secondary outcomes included stuttering frequency (%SS, stuttering severity ratings by the parents and therapist, severity rating by the child, health-related quality of life, emotional and behavioral problems, and speech attitude.Percentage of non-stuttering children for direct treatment was 76.5% (65/85 versus 71.4% (65/91 for indirect treatment (Odds Ratio (OR, 0.6; 95% CI, 0.1-2.4, p = .42. At 3 months, children treated by direct treatment showed a greater decline in %SS (significant interaction time x therapy: β = -1.89; t(282.82 = -2.807, p = .005. At 18 months, stuttering frequency was 1.2% (SD 2.1 for direct treatment and 1.5% (SD 2.1 for indirect treatment. Direct treatment had slightly better scores on most other secondary outcome measures, but no differences between treatment approaches were significant.Direct treatment decreased stuttering more quickly during the first three months of treatment. At 18 months, however, clinical outcomes for direct and indirect treatment were comparable. These results imply that at 18 months post treatment onset, both treatments are roughly equal in treating developmental stuttering in ways that surpass expectations of natural recovery. Follow-up data are needed to confirm these findings in the longer term

  3. Restart Operator Meta-heuristics for a Problem-Oriented Evolutionary Strategies Algorithm in Inverse Mathematical MISO Modelling Problem Solving

    Science.gov (United States)

    Ryzhikov, I. S.; Semenkin, E. S.

    2017-02-01

    This study is focused on solving an inverse mathematical modelling problem for dynamical systems based on observation data and control inputs. The mathematical model is being searched in the form of a linear differential equation, which determines the system with multiple inputs and a single output, and a vector of the initial point coordinates. The described problem is complex and multimodal and for this reason the proposed evolutionary-based optimization technique, which is oriented on a dynamical system identification problem, was applied. To improve its performance an algorithm restart operator was implemented.

  4. Evaluation of the Doraiswamy-Thompson winter wheat crop calendar model incorporating a modified spring restart sequence

    Science.gov (United States)

    Taylor, T. W.; Ravet, F. W.; Smika, D. (Principal Investigator)

    1981-01-01

    The Robertson phenology was used to provide growth stage information to a wheat stress indicator mode. A stress indicator model demands two acurate predictions from a crop calendar: date of spring growth initiation; and crop calendar stage at growth initiation. Several approaches for restarting the Robertson phenology model at spring growth initiation were studied. Although best results were obtained with a solar thermal unit method, an alternate approach which indicates soil temperature as the controlling parameter for spring growth initiation was selected and tested. The modified model (Doraiswamy-Thompson) is compared to LACIE-Robertson model predictions.

  5. Radiative corrections for the LHC and linear collider era

    NARCIS (Netherlands)

    E. Laenen; D. Wackeroth

    2009-01-01

    We emphasize the importance of including radiative corrections when extracting physics from colliders such as the Tevatron Run II at Fermilab, the Large Hadron Collider (LHC) at CERN, and a future linear collider (LC). We review both well-tested methods and recent advances for calculating these corr

  6. Analysis of factors associated with hesitation to restart farming after depopulation of animals due to 2010 foot-and-mouth disease epidemic in Japan

    Science.gov (United States)

    KADOWAKI, Hazumu; KAYANO, Taishi; TOBINAGA, Takaharu; TSUTSUMI, Atsuro; WATARI, Michiko; MAKITA, Kohei

    2016-01-01

    An outbreak of foot-and-mouth disease (FMD) occurred in Miyazaki Prefecture, Japan, in 2010. This epidemic was controlled with culling and vaccination, and resulted in the death of nearly 290,000 animals. This paper describes the factors associated with hesitation to restart farming after the epidemic. A questionnaire survey was conducted to assess the mental health of farmers one year after the end of the FMD epidemic in affected areas, and univariate and multivariable analyses were performed. Of 773 farms which had answered the question about restart farming, 55.4% (428/773) had resumed or were planning to resume operation. The farms hesitated restarting were characterized by small scale (P=0.06) and having multiple sources of income (P<0.01). Personal attributes associated with hesitation to restart were advanced age of the owner (P<0.01), with someone with bad physical conditions (P=0.04) and small family size (P<0.01). Factors related to disease control during the epidemic that were associated with hesitation to restart were vaccination of animals (P<0.01), not assisting with culling on other farms (P<0.01), and higher satisfaction with information provided by the government (P=0.02). We found that farmers hesitated to resume farming because they had a limited labor force, had an alternative business or were mentally distressed during disease control. PMID:27149890

  7. The CERN SPS proton–antiproton collider

    CERN Document Server

    Schmidt, Rudiger

    2016-01-01

    One of CERN's most ambitious and successful projects was the search for the intermediate bosons, W and Z [1]. The accelerator part of the project relied on a number of innovations in accelerator physics and technology. The invention of the method of stochastic cooling and the extension by many orders of magnitude beyond the initial proof of principle demonstration allowed the construction of the Antiproton Accumulator. Major modifications to the 26 GeV PS complex and the conversion of the 300 GeV SPS, which had just started up as an accelerator, to a collider were required. The SPS collider had to master the beam–beam effect far beyond limits reached before and had to function in a tight symbiosis with the UA1 and UA2 experiments.

  8. Anomalous interactions at a linear collider

    Indian Academy of Sciences (India)

    Sudhansu S Biswal; Debajyoti Choudhury; Rohini M Godbole; Ritesh K Singh

    2007-11-01

    We examine, in a model independent way, the sensitivity of a linear collider to the couplings of a light Higgs boson to a pair of gauge bosons, including the possibility of CP violation. We construct several observables that probe the various possible anomalous couplings. For an intermediate mass Higgs, a collider operating at a center of mass energy of 500 GeV and with an integrated luminosity of 500 fb-1 is shown to be able to constrain the vertex at the few per cent level, with even higher sensitivity for some of the couplings. However, lack of sufficient number of observables as well as contamination from the vertex limits the precision to which anomalous part of the coupling can be probed.

  9. Reverse Emittance Exchange for Muon Colliders

    Energy Technology Data Exchange (ETDEWEB)

    V. Ivanov, A. Afanasev, C.M. Ankenbrandt, R.P. Johnson, G.M. Wang, S.A. Bogacz, Y.S. Derbenev

    2009-05-01

    Muon collider luminosity depends on the number of muons in the storage ring and on the transverse size of the beams in collision. Ionization cooling as it is currently envisioned will not cool the beam sizes sufficiently well to provide adequate luminosity without large muon intensities. Six-dimensional cooling schemes will reduce the longitudinal emittance of a muon beam so that smaller high frequency RF cavities can be used for later stages of cooling and for acceleration. However, the bunch length at collision energy is then shorter than needed to match the interaction region beta function. New ideas to shrink transverse beam dimensions by lengthening each bunch will help achieve high luminosity in muon colliders. Analytic expressions for the reverse emittance exchange mechanism were derived, including a new resonant method of beam focusing.

  10. Luminosity Spectrum Reconstruction at Linear Colliders

    CERN Document Server

    Poss, Stéphane

    2014-01-01

    A good knowledge of the luminosity spectrum is mandatory for many measurements at future e+e- colliders. As the beam-parameters determining the luminosity spectrum cannot be measured precisely, the luminosity spectrum has to be measured through a gauge process with the detector. The measured distributions, used to reconstruct the spectrum, depend on Initial State Radiation, cross-section, and Final State Radiation. To extract the basic luminosity spectrum, a parametric model of the luminosity spectrum is created, in this case the spectrum at the 3 TeV Compact Linear Collider (CLIC). The model is used within a reweighting technique to extract the luminosity spectrum from measured Bhabha event observables, taking all relevant effects into account. The centre-of-mass energy spectrum is reconstructed within 5% over the full validity range of the model. The reconstructed spectrum does not result in a significant bias or systematic uncertainty in the exemplary physics benchmark process of smuon pair production.

  11. Nonlinear Energy Collimation System for Linear Colliders

    CERN Document Server

    Resta-Lopez, Javier

    2011-01-01

    The post-linac energy collimation system of multi-TeV linear colliders is designed to fulfil an important function of protection of the Beam Delivery System (BDS) against miss-steered beams likely generated by failure modes in the main linac. For the case of the Compact Linear Collider (CLIC), the energy collimators are required to withstand the impact of a full bunch train in case of failure. This is a very challenging task, assuming the nominal CLIC beam parameters at 1.5 TeV beam energy. The increase of the transverse spot size at the collimators using nonlinear magnets is a potential solution to guarantee the survival of the collimators. In this paper we present an alternative nonlinear optics based on a skew sextupole pair for energy collimation. Performance simulation results are also presented.

  12. Suppressing Electron Cloud in Future Linear Colliders

    CERN Document Server

    Pivi, M T F; Le Pimpec, Frederic; Raubenheimer, Tor O

    2005-01-01

    Any accelerator circulating positively charged beams can suffer from a build-up of an electron cloud in the beam pipe. The cloud develops through ionization of residual gases, synchrotron radiation and secondary electron emission and, when severe, can cause instability, emittance blow-up or loss of the circulating beam. The electron cloud is potentially a limiting effect for both the Large Hadron Collider (LHC) and the International Linear Collider (ILC). For the ILC positron damping ring, the development of the electron cloud must be suppressed. This paper presents the various effects of the electron cloud and evaluates their significance. It also discusses the state-of-the-art of the ongoing international R&D program to study potential remedies to reduce the secondary electron yield to acceptably low levels.

  13. Slepton Flavor Physics at Linear Colliders

    CERN Document Server

    Dine, Michael; Thomas, S; Dine, Michael; Grossman, Yuval; Thomas, Scott

    2001-01-01

    If low energy supersymmetry is realized in nature it is possible that a first generation linear collider will only have access to some of the superpartners with electroweak quantum numbers. Among these, sleptons can provide sensitive probes for lepton flavor violation through potentially dramatic lepton violating signals. Theoretical proposals to understand the absence of low energy quark and lepton flavor changing neutral currents are surveyed and many are found to predict observable slepton flavor violating signals at linear colliders. The observation or absence of such sflavor violation will thus provide important indirect clues to very high energy physics. Previous analyses of slepton flavor oscillations are also extended to include the effects of finite width and mass differences.

  14. Collider Signatures of Flavorful Higgs Bosons

    CERN Document Server

    Altmannshofer, Wolfgang; Gori, Stefania; Lotito, Matteo; Martone, Mario; Tuckler, Douglas

    2016-01-01

    Motivated by our limited knowledge of the Higgs couplings to first two generation fermions, we analyze the collider phenomenology of a class of two Higgs doublet models (2HDMs) with a non-standard Yukawa sector. One Higgs doublet is mainly responsible for the masses of the weak gauge bosons and the third generation fermions, while the second Higgs doublet provides mass for the lighter fermion generations. The characteristic collider signatures of this setup differ significantly from well-studied 2HDMs with natural flavor conservation, flavor alignment, or minimal flavor violation. New production mechanisms for the heavy scalar, pseudoscalar, and charged Higgs involving second generation quarks can become dominant. The most interesting decay modes include H/A -> cc, tc, {\\mu}{\\mu}, {\\tau}{\\mu} and H+ -> cb, cs, {\\mu}{\

  15. Heavy ions at the Future Circular Collider

    CERN Document Server

    Dainese, A; Armesto, N; d'Enterria, D; Jowett, J M; Lansberg, J -P; Milhano, J G; Salgado, C A; Schaumann, M; van Leeuwen, M; Albacete, J L; Andronic, A; Antonioli, P; Apolinario, L; Bass, S; Beraudo, A; Bilandzic, A; Borsanyi, S; Braun-Munzinger, P; Chen, Z; Mendez, L Cunqueiro; Denicol, G S; Eskola, K J; Floerchinger, S; Fujii, H; Giubellino, P; Greiner, C; Grosse-Oetringhaus, J F; Ko, C -M; Kotko, P; Krajczar, K; Kutak, K; Laine, M; Liu, Y; Lombardo, M P; Luzum, M; Marquet, C; Masciocchi, S; Okorokov, V; Paquet, J -F; Paukkunen, H; Petreska, E; Pierog, T; Ploskon, M; Ratti, C; Rezaeian, A H; Riegler, W; Rojo, J; Roland, C; Rossi, A; Salam, G P; Sapeta, S; Schicker, R; Schmidt, C; Stachel, J; Uphoff, J; van Hameren, A; Watanabe, K; Xiao, B -W; Yuan, F; Zaslavsky, D; Zhou, K; Zhuang, P

    2016-01-01

    The Future Circular Collider (FCC) Study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron-hadron collision mode, seven times larger than the nominal LHC energies. Operating such machine with heavy ions is an option that is being considered in the accelerator design studies. It would provide, for example, Pb-Pb and p-Pb collisions at sqrt{s_NN} = 39 and 63 TeV, respectively, per nucleon-nucleon collision, with integrated luminosities above 30 nb^-1 per month for Pb-Pb. This is a report by the working group on heavy-ion physics of the FCC Study. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of the Quark-Gluon Plasma, of gluon saturation, of photon-induced collisions, as well as connections with other fields of high-energy physics.

  16. Future high energy colliders symposium. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Parsa, Z. [Univ. of California, Santa Barbara, CA (United States). Institute for Theoretical Physics]|[Brookhaven National Lab., Upton, CA (United States)

    1996-12-31

    A `Future High Energy Colliders` Symposium was held October 21-25, 1996 at the Institute for Theoretical Physics (ITP) in Santa Barbara. This was one of the 3 symposia hosted by the ITP and supported by its sponsor, the National Science Foundation, as part of a 5 month program on `New Ideas for Particle Accelerators`. The long term program and symposia were organized and coordinated by Dr. Zohreh Parsa of Brookhaven National Laboratory/ITP. The purpose of the symposium was to discuss the future direction of high energy physics by bringing together leaders from the theoretical, experimental and accelerator physics communities. Their talks provided personal perspectives on the physics objectives and the technology demands of future high energy colliders. Collectively, they formed a vision for where the field should be heading and how it might best reach its objectives.

  17. 1st Large Hadron Collider Physics Conference

    CERN Document Server

    Juste, A; Martínez, M; Riu, I; Sorin, V

    2013-01-01

    The conference is the result of merging two series of international conferences, "Physics at Large Hadron Collider" (PLHC2012) and "Hadron Collider Physics Symposium" (HCP2012). With a program devoted to topics such as the Standard Model and Beyond, the Higgs Boson, Supersymmetry, Beauty and Heavy Ion Physics, the conference aims at providing a lively forum for discussion between experimenters and theorists of the latest results and of new ideas. LHCP 2013 will be hosted by IFAE (Institut de Fisica d'Altes Energies) in Barcelona (Spain), and will take place from May 13 to 18, 2013. The venue will be the Hotel Catalonia Plaza, Plaza España (Barcelona). More information will be posted soon. For questions, please contact lhcp2013@ifae.es.

  18. Delayed childbearing.

    Science.gov (United States)

    Francis, H H

    1985-06-01

    In many Western nations, including England and Wales, Sweden, and the US, there is a current trend towards delayed childbearing because of women's pursuit of a career, later marriage, a longer interval between marriage and the 1st birth, and the increasing number of divorcees having children in a 2nd marriage. Wives of men in social classes I and II in England and Wales are, on average, having their 1st child at 27.9 years, 1.6 years later than in 1973, and in social classes IV and V, 1.0 years later than in 1973, at a mean age of 23.7 years. Consequently, the total period fertility rate for British women aged 30-34 years, 35-39 years, and 40 and over increased by 4%, 2%, and 4%, respectively, between 1982-83, in contrast to reductions of 2% and 3%, respectively, in the 15-19 year and 20-24 year age groups, with the 25-29-year-olds remaining static. The average maternal mortality for all parties in England and Wales during 1976-78 was 106/million for adolescents, 70.4/million for 20-24 year-olds, and 1162/million for those aged 40 years and older. The specific obstetric and allied conditions which increase with age are the hypertensive diseases of pregnancy, hemorrhage, pulmonary embolism, abortion, cardiac disease, caesarean section, ruptured uterus, and amniotic fluid embolism. The Swedish Medical Birth Registry of all live births and perinatal deaths since 1973 has shown that the risk of late fetal death is significantly greater in women aged 30-39 years than in those of the same parity and gravidity aged 20-24 years. The risk of giving birth to low birth weight babies preterm and at term and of premature labor are similarly increased. The early neonatal death rate also was increased for primigravidas and nulliparas in the 30-39 year age group but not in parous women. This is, in part, due to the rise in incidence of fetal abnormalities with advancing maternal age because of chromosomal and nonchromosomal anomalies. These also appear to be the cause of the

  19. Two-photon ionization of colliding atoms

    Energy Technology Data Exchange (ETDEWEB)

    Nayfeh, M.H.

    1977-09-01

    Semiclassical expressions of two-photon ionization of two colliding atoms are derived for a wide range of electromagnetic field intensity and detunings from the isolated atom line. The dependence of the ionization yield on the details of the interaction potential of the system is derived. This process promises an extremely sensitive method for studying line broadening on the far wing, especially when absorption or fluorescence becomes very weak.

  20. The Large Hadron Collider Pop Up Book

    CERN Multimedia

    2013-01-01

    Discover the ATLAS experiment in full 3D pop-up in this promotional video for the Large Hadron Collider pop-up book. The book contains 16 pop-ups telling the story of how the experiment works and its quest to understand what the universe is made of. It is now available in English, French and German. Paper engineer Anton Radevsky, texts Emma Sanders.

  1. Top physics at the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Margaroli, Fabrizio; /Purdue U.

    2007-10-01

    The top quark has been discovered in 1995 at the CDF and DO experiments located in the Tevatron ring at the Fermilab laboratory. After more than a decade the Tevatron collider, with its center-of-mass energy collisions of 1.96 TeV, is still the only machine capable of producing such exceptionally heavy particle. Here I present a selection of the most recent CDF and DO measurements performed analyzing {approx} 1 fb{sup -1} of integrated luminosity.

  2. Loans may keep CERN collider on target

    CERN Multimedia

    Abbott, A

    1996-01-01

    The European Laboratory for Particle Physics (CERN) is considering taking out bank loans to fund its Large Hadron Collider project. CERN officials are evaluating this option in view of the German government's decision to substantially reduce its annual contributions to the project. They state that the bank loans may be the only way to complete the project by the year 2005, especially if other contributing nations follow Germany's lead.

  3. Charm-Hadron Production at Hadron Colliders

    CERN Document Server

    Watson, Miriam; The ATLAS collaboration

    2016-01-01

    Recent results on charm hadron production are presented, using data recorded in proton-proton collisions at the Large Hadron Collider and in proton-antiproton collisions at the Tevatron. These results include the production of charmonium and of open charm mesons, and their comparison with theoretical predictions. Measurements of the associated production of hidden or open charm mesons with additional quarkonium states are also presented.

  4. Two-Beam Linear Colliders - Special Issues

    CERN Document Server

    Corsini, Roberto

    2010-01-01

    The path towards a multi-TeV e+e- linear collider proposed by the CLIC study is based on the Two-Beam Acceleration (TBA) scheme. Such a scheme is promising in term of efficiency, reliability and cost. The rationale behind the two-beam scheme is discussed in the paper, together with the special issues related to this technology and the R&D needed to demonstrate its feasibility.

  5. German lab wins linear collider contest

    CERN Multimedia

    Cartlidge, Edwin

    2004-01-01

    Particle physicists have chosen to base the proposed International Linear Collider on superconducting technology developed by an international collaboration centred on the DESY lab in Germany. The superconducting approach was chosen by an internatinal panel ahead of a rival technology developed at Stanford in the US and the KEK lab in Japan. The eagerly-awaited decision was announced at the International Conference on High Energy Physics in Beijing today (½ page)

  6. 1987 DOE review: First collider run operation

    Energy Technology Data Exchange (ETDEWEB)

    Childress, S.; Crawford, J.; Dugan, G.; Edwards, H.; Finley, D.A.; Fowler, W.B.; Harrison, M.; Holmes, S.; Makara, J.N.; Malamud, E.

    1987-05-01

    This review covers the operations of the first run of the 1.8 TeV superconducting super collider. The papers enclosed cover: PBAR source status, fixed target operation, Tevatron cryogenic reliability and capacity upgrade, Tevatron Energy upgrade progress and plans, status of the D0 low beta insertion, 1.8 K and 4.7 K refrigeration for low-..beta.. quadrupoles, progress and plans for the LINAC and booster, near term and long term and long term performance improvements.

  7. Production of electroweak bosons at colliders

    Indian Academy of Sciences (India)

    Matthias U Mozer

    2012-10-01

    The collider experiments at the Tevatron and LHC are accumulating samples of electroweak bosons of unprecedented size. These huge samples can be used to observe rare processes, such as diboson production which have the potential to show enhancements due to new physics. Alternatively, the great statistical power of the samples allows for detailed studies of electroweak production mechanisms and correspondingly QCD and the proton structure.

  8. Large Hadron Collider The Discovery Machine

    CERN Multimedia

    2008-01-01

    The mammoth machine, after a nine-year construction period, is scheduled (touch wood) to begin producing its beams of particles later this year. The commissioning process is planned to proceed from one beam to two beams to colliding beams; from lower energies to the terascale; from weaker test intensities to stronger ones suitable for producing data at useful rates but more difficult to control.

  9. Large Hadron Collider commissioning and first operation.

    Science.gov (United States)

    Myers, S

    2012-02-28

    A history of the commissioning and the very successful early operation of the Large Hadron Collider (LHC) is described. The accident that interrupted the first commissioning, its repair and the enhanced protection system put in place are fully described. The LHC beam commissioning and operational performance are reviewed for the period from 2010 to mid-2011. Preliminary plans for operation and future upgrades for the LHC are given for the short and medium term.

  10. Neutrino Factory and Muon Collider Fellow

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Gail G. [Univ. of California, Riverside, CA (United States); Snopak, Pavel [Univ. of California, Riverside, CA (United States); Bao, Yu [Univ. of California, Riverside, CA (United States)

    2015-03-20

    Muons are fundamental particles like electrons but much more massive. Muon accelerators can provide physics opportunities similar to those of electron accelerators, but because of the larger mass muons lose less energy to radiation, allowing more compact facilities with lower operating costs. The way muon beams are produced makes them too large to fit into the vacuum chamber of a cost-effective accelerator, and the short muon lifetime means that the beams must be reduced in size rather quickly, without losing too many of the muons. This reduction in size is called "cooling." Ionization cooling is a new technique that can accomplish such cooling. Intense muon beams can then be accelerated and injected into a storage ring, where they can be used to produce neutrino beams through their decays or collided with muons of the opposite charge to produce a muon collider, similar to an electron-positron collider. We report on the research carried out at the University of California, Riverside, towards producing such muon accelerators, as part of the Muon Accelerator Program based at Fermilab. Since this research was carried out in a university environment, we were able to involve both undergraduate and graduate students.

  11. Linear collider IR and final focus introduction

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, J.; Burke, D.

    1991-09-01

    The Linear Collider subgroup of the Accelerator Physics working group concerned itself with all aspects of the Next Linear Collider (NLC) design from the end of the accelerating structure to and through the interaction region. Within this region are: (1) a collimation section, (2) muon protection (of the detector from the collimator), (3) final focus system, (4) interaction point physics, and (5) detector masking from synchrotron radiation and beam-beam pair production. These areas of study are indicated schematically in Fig. 1. The parameters for the Next Linear Collider are still in motion, but attention has settled on a handful of parameter sets. Energies under consideration vary from 0.5 to 1.5 TeV in the center of mass, and luminosities vary from 10{sup 33} to 10{sup 34} cm{sup {minus}2}s{sup {minus}1}. To be concrete we chose as a guide for our studies the parameter sets labeled F and G, Table 1 from Palmer. These cover large and small crossing angle cases and 0.4 m to 1.8 m of free length at the interaction point.

  12. The International Linear Collider - Physics and Perspectives

    CERN Document Server

    ,

    2016-01-01

    With the discovery of a Higgs boson at LHC, all particles of the Standard Model seem to have been observed experimentally, yet many questions are left unanswered. The discovery has intensified the planning for future high-energy colliders, which aim to probe the Standard Model and the mechanism of electroweak symmetry breaking with higher precision and to extend and complement the search for new particles currently under way at the LHC. The most mature option for such a future facility is the International Linear Collider ILC, an electron-positron collider with a centre-of-mass energy of 500 GeV, and the potential for upgrades into the TeV region. The ILC will fully explore the Higgs sector, including model-independent coupling and width measurements, direct measurements of the coupling to the top quark and the Higgs self-coupling, enable precision measurements of top quark properties and couplings as well as other electroweak precision measurements and provide extensive discovery potential for new physics co...

  13. Progress on the CLIC Linear Collider Study

    CERN Document Server

    Guignard, Gilbert

    2001-01-01

    The CLIC study aims at a multi-TeV, high luminosity e+e- linear collider design. Beam acceleration uses high frequency (30 GHz), normal conducting structures operating at high accelerating gradients, in order to reduce the length and, in consequence, the cost of the linac. The cost-effective RF power production scheme, based on the so-called Two-beam Acceleration method, enables electrons and positrons to be collided at energies ranging from ~ 0.1 TeV up to a maximum of 5 TeV, in stages. A road map has been drawn up to indicate the research and development necessary to demonstrate the technical feasibility of a 3 TeV centre-of-mass collider with a luminosity of 1035 cm-2s-1. Considerable progress has been made in meeting the challenges associated with the CLIC technology and the present paper briefly reviews some of them. In particular, the status is given of the studies on the CLIC high-gradient structures, the dynamic time-dependent effects, the stabilisation of the vibration and the beam delivery system. T...

  14. The Dark Penguin Shines Light at Colliders

    CERN Document Server

    Primulando, Reinard; Tsai, Yuhsin

    2015-01-01

    Collider experiments are one of the most promising ways to constrain Dark Matter (DM) interactions. For several types of DM-Standard Model couplings, a meaningful interpretation of the results requires to go beyond effective field theory, considering simplified models with light mediators. This is especially important in the case of loop-mediated interactions. In this paper we perform the first simplified model study of the magnetic dipole interacting DM, by including the one-loop momentum-dependent form factors that mediate the coupling -- given by the Dark Penguin -- in collider processes. We compute bounds from the monojet, monophoton, and diphoton searches at the $8$ and $14$ TeV LHC, and compare the results to those of direct and indirect detection experiments. Future searches at the $100$ TeV hadron collider and at the ILC are also addressed. We find that the optimal search strategy requires loose cuts on the missing transverse energy, to capture the enhancement of the form factors near the threshold fo...

  15. Advanced Concepts for Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Yaroslav Derbenev

    2002-08-01

    A superconducting energy recovery linac (ERL) of 5 to 10 GeV was proposed earlier as an alternative to electron storage rings to deliver polarized electron beam for electron-ion collider (EIC). To enhance the utilization efficiency of electron beam from a polarized source, it is proposed to complement the ERL by circulator ring (CR) wherein the injected electrons undergo up to 100 revolutions colliding with the ion beam. In this way, electron injector and linac operate in pulsed current (beam energy recovery) regime of a relatively low average current, while the polarization is still easily delivered and preserved. To make it also easier delivering and manipulating the proton and light ion polarization, twisted (figure 8) synchrotrons are proposed for heavy particle booster and collider ring. Same type of beam orbit can be used then for electron circulator. Electron cooling (EC) of the ion beam is considered an inevitable component of high luminosity EIC (1033/s. cm2 or above). It is recognized that EC also gives a possibility to obtain very short ion bunches, that allows much stronger final focusing. At the same time, short bunches make feasible the crab crossing (and traveling focus for ion beam) at collision points, hence, allow maximizing the collision rate. As a result, one can anticipate the luminosity increase by one or two orders of magnitude.

  16. Searching for dark matter at colliders

    Science.gov (United States)

    Richard, Francois; Arcadi, Giorgio; Mambrini, Yann

    2015-04-01

    Dark Matter (DM) detection prospects at future colliders are reviewed under the assumption that DM particles are fermions of the Majorana or Dirac type. Although the discussion is quite general, one will keep in mind the recently proposed candidate based on an excess of energetic photons observed in the center of our Galaxy with the Fermi-LAT satellite. In the first part we will assume that DM interactions are mediated by vector bosons, or . In the case of -boson Direct Detection limits force only axial couplings with the DM. This solution can be naturally accommodated by Majorana DM but is disfavored by the GC excess. Viable scenarios can be instead found in the case of mediator. These scenarios can be tested at colliders through ISR events, . A sensitive background reduction can be achieved by using highly polarized beams. In the second part scalar particles, in particular Higgs particles, have been considered as mediators. The case of the SM Higgs mediator is excluded by limits on the invisible branching ratio of the Higgs. On the contrary particularly interesting is the case in which the DM interactions are mediated by the pseudoscalar state in two Higgs-doublet model scenarios. In this last case the main collider signature is.

  17. Future Circular Colliders Study, Kickoff Meeting

    CERN Document Server

    2014-01-01

    This meeting is the starting point of a five-year international design study called “Future Circular Colliders” (FCC) with emphasis on a hadron collider with a centre-of-mass energy of the order of 100 TeV in a new 80-100 km tunnel as a long-term goal. The design study includes a 90-400 GeV lepton collider, seen as a potential intermediate step. It also examines a lepton-hadron collider option. The international kick-off meeting for the FCC design study will be held at the University of Geneva, Unimail site, on 12–15 February 2014. The scope of this meeting will be to discuss the main study topics and to prepare the groundwork for the establishment of international collaborations and future studies. The formal part of the meeting will start at noon on Wednesday 12 February and last until noon on Friday 14 February. It will be followed by break-out sessions on the various parts of the project on the Friday afternoon, with summary sessions until noon on Saturday 15 February.

  18. Muon Collider Machine-Detector Interface

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, Nikolai V.; /Fermilab

    2011-08-01

    In order to realize the high physics potential of a Muon Collider (MC) a high luminosity of {mu}{sup +}{mu}{sup -}-collisions at the Interaction Point (IP) in the TeV range must be achieved ({approx}10{sup 34} cm{sup -2}s{sup -1}). To reach this goal, a number of demanding requirements on the collider optics and the IR hardware - arising from the short muon lifetime and from relatively large values of the transverse emittance and momentum spread in muon beams that can realistically be obtained with ionization cooling should be satisfied. These requirements are aggravated by limitations on the quadrupole gradients as well as by the necessity to protect superconducting magnets and collider detectors from muon decay products. The overall detector performance in this domain is strongly dependent on the background particle rates in various sub-detectors. The deleterious effects of the background and radiation environment produced by the beam in the ring are very important issues in the Interaction Region (IR), detector and Machine-Detector Interface (MDI) designs. This report is based on studies presented very recently.

  19. 2001 Report on the Next Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Gronnberg, J; Breidenbach; Burke, D; Corlett, J; Dombeck, T; Markiewicz, T

    2001-08-28

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider.

  20. Seventh International Accelerator School for Linear Colliders

    CERN Document Server

    Organizers of the Seventh International Accelerator School for Linear Colliders

    2012-01-01

    We are pleased to announce the Seventh International Accelerator School for Linear Colliders. This school is a continuation of the series of schools which began six years ago.  The first school was held in 2006 in Sokendai, Japan, the second in 2007 in Erice, Italy, the third in 2008 in Oakbrook Hills, USA, the fourth in 2009 in Huairou, China, the fifth in 2010 in Villars-sur-Ollon, Switzerland, and the sixth in 2011 in Pacific Grove, USA.   The school is organized by the International Linear Collider (ILC) Global Design Effort (GDE), the Compact Linear Collider (CLIC) and the International Committee for Future Accelerators (ICFA) Beam Dynamics Panel. The school this year will take place at the Radisson Blu Hotel, Indore, India from November 27 to December 8, 2012. It is hosted by the Raja Ramanna Center for Advanced Technology (RRCAT) and sponsored by a number of funding agencies and institutions around the world including the U.S. Department of Energy (DOE), the U.S. National Science...

  1. Delayed onset, protracted delirium and aspiration pneumonitis associated with a combination of clozapine and electroconvulsive therapy

    Directory of Open Access Journals (Sweden)

    N Manjunatha

    2011-01-01

    Full Text Available Few studies reported the efficacy and safety in combination of clozapine and electroconvulsive therapy (ECT in schizophrenia; systematic studies are lacking. Side effects like seizure, and confusional state are reported. Authors report two cases of delayed onset/protracted delirium with ECT and clozapine in schizophrenia, one of whom developed aspiration pneumonitis possibly due to clozapine hyper-salivation. Delirium improved with stopping of ECT and clozapine. Clozapine monotherapy restarted to previous dosages in both cases without recurrence of delirium. Authors recommend for careful monitoring for delirium in ECT augmentation on high dose clozapine. Unilateral ECT may be preferred for augmenting clozapine.

  2. Colliding beam physics at Fermilab: interaction regions, beam storage, antiproton cooling, production, and colliding

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J.K. (ed.)

    1977-01-01

    The purpose of the colliding beams experment department at Fermilab was to bring about collisions of the stored beams in the energy doubler/saver and main ring, and construct experimental areas with appropriate detectors. To explore the feasibility of using the main ring as a storage device, several studies were carried out to investigate beam growth, loss, and the backgrounds in detectors at possible intersection regions. This range of developments constituted the major topics at the 1977 Summer Study reported here. Emphasis in part one is on interaction regions, beam storage, antiproton cooling, production, and colliding. 40 papers from this part are included in the data base. (GHT)

  3. Chromaticity correction for a muon collider optics

    Energy Technology Data Exchange (ETDEWEB)

    Alexahin, Y.; Gianfelice-Wendt, E.; Kapin, V.; /Fermilab

    2011-03-01

    Muon Collider (MC) is a promising candidate for the next energy frontier machine. However, in order to obtain peak luminosity in the 10{sup 34} cm{sup 2}s{sup -1} range the collider lattice designmust satisfy a number of stringent requirements. In particular the expected large momentum spread of the muon beam and the very small {beta}* call for a careful correction of the chromatic effects. Here we present a particular solution for the interaction region (IR) optics whose distinctive feature is a three-sextupole local chromatic correction scheme. The scheme may be applied to other future machines where chromatic effects are expected to be large. The expected large muon energy spread requires the optics to be stable over a wide range of momenta whereas the required luminosity calls for {beta}* in the mm range. To avoid luminosity degradation due to hour-glass effect, the bunch length must be comparatively small. To keep the needed RF voltage within feasible limits the momentum compaction factor must be small over the wide range of momenta. A low {beta}* means high sensitivity to alignment and field errors of the Interaction Region (IR) quadrupoles and large chromatic effects which limit the momentum range of optics stability and require strong correction sextupoles, which eventually limit the Dynamic Aperture (DA). Finally, the ring circumference should be as small as possible, luminosity being inversely proportional to the collider length. A promising solution for a 1.5 TeV center of mass energy MC with {beta}* = 1 m in both planes has been proposed. This {beta}* value has been chosen as a compromise between luminosity and feasibility based on the magnet design and energy deposition considerations. The proposed solution for the IR optics together with a new flexible momentum compaction arc cell design allows to satisfy all requirements and is relatively insensitive to the beam-beam effect.

  4. Beam loss mechanisms in relativistic heavy-ion colliders

    CERN Document Server

    Bruce, Roderik; Gilardoni, S; Wallén, E

    2009-01-01

    The Large Hadron Collider (LHC), the largest particle accelerator ever built, is presently under commissioning at the European Organization for Nuclear Research (CERN). It will collide beams of protons, and later Pb82+ ions, at ultrarelativistic energies. Because of its unprecedented energy, the operation of the LHC with heavy ions will present beam physics challenges not encountered in previous colliders. Beam loss processes that are harmless in the presently largest operational heavy-ion collider, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, risk to cause quenches of superconducting magnets in the LHC. Interactions between colliding beams of ultrarelativistic heavy ions, or between beam ions and collimators, give rise to nuclear fragmentation. The resulting isotopes could have a charge-to-mass ratio different from the main beam and therefore follow dispersive orbits until they are lost. Depending on the machine conditions and the ion species, these losses could occur in loca...

  5. DIS prospects at the future muon collider facility

    Energy Technology Data Exchange (ETDEWEB)

    Yu, J., FERMI

    1998-07-01

    We discuss prospects of deep inelastic scattering physics capabilities at the future muon collider facility. In addition to {mu}{sup +}{mu}{sup -} collider itself, the facility provides other possibilities. Among the possibilities, we present muon-proton collider and neutrino fixed target programs at the muon collider facility. This {mu}-p collider program extends kinematic reach and luminosity by an order of magnitude, increasing the possibility of search for new exotic particles. Perhaps most intriguing DIS prospects come from utilizing high intensity neutrino beam resulting from continuous decays of muons in various sections of the muon collider facility. One of the most interesting findings is a precision measurement of electroweak mixing angle, sin{sup 2}{theta}{sub W}, which can be achieved to the precision equivalent to {delta}M{sub W}{approximately} 30MeV.

  6. A Complete Scheme for a Muon Collider

    CERN Document Server

    Palmer, Robert B; Fernow, Richard C; Gallardo, Juan Carlos; Kirk, Harold G; Alexahin, Yuri; Neuffer, David; Kahn, Stephen Alan; Summers, Don J

    2007-01-01

    A complete scheme for production, cooling, acceleration, and ring for a 1.5 TeV center of mass muon collider is presented, together with parameters for two higher energy machines. The schemes starts with the front end of a proposed neutrino factory that yields bunch trains of both muon signs. Six dimensional cooling in long-period helical lattices reduces the longitudinal emittance until it becomes possible to merge the trains into single bunches, one of each sign. Further cooling in all dimensions is applied to the single bunches in further helical lattices. Final transverse cooling to the required parameters is achieved in 50 T solenoids.

  7. Transverse cooling in the muon collider

    Energy Technology Data Exchange (ETDEWEB)

    Fernow, R.C.; Gallardo, J.C.; Kirk, H.G.; Palmer, R.B.

    1998-07-01

    Ionization cooling is the preferred method for reducing the emittance of muon beams in a muon collider. The method described here uses passive liquid hydrogen absorbers and rf acceleration in an alternating lattice of solenoids. The authors consider the basic principles of ionization cooling, indicating the reasons for selecting various parameters. Tracking simulations are used to make detailed examinations of effects on the beam, such as transmission losses, transverse cooling, bunch lengthening, and introduction of energy spread. The system reduces the overall 6-dimensional emittance to 44% of its initial value.

  8. Future Circular Collider study week 2017

    CERN Document Server

    2017-01-01

    The annual meetings of the worldwide Future Circular Collider study (FCC) are major international events that review the progress in every domain which is relevant to develop feasible concepts for a next generation frontier particle accelerate based high-energy physics research infrastructure. This 3rd meeting is jointly organised by CERN and DESY. It is also the annual meeting of the EuroCirCol EC Horizon 2020 Research and Innovation Action project. Previous events took place in Washington and Rome. In 2017 the FCC Week will take place in Berlin, Germany between May 29 and June 2.

  9. Broader Impacts of the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Bardeen, M.; Ruchti, R.

    2005-08-01

    Large-scale scientific endeavors such as the International Linear Collider Project can have a lasting impact on education and outreach to our society. The ILC will provide a discovery platform for frontier physical science and it will also provide a discovery platform for broader impacts and social science. The importance of Broader Impacts of Science in general and the ILC in particular are described. Additionally, a synopsis of education and outreach activities carried out as an integral part of the Snowmass ILC Workshop is provided.

  10. Colliding Plane Waves in String Theory

    CERN Document Server

    Chen, B; Furuta, K; Lin, F L; Chen, Bin; Chu, Chong-Sun; Furuta, Ko; Lin, Feng-Li

    2004-01-01

    We construct colliding plane wave solutions in higher dimensional gravity theory with dilaton and higher form flux, which appears naturally in the low energy theory of string theory. Especially, the role of the junction condition in constructing the solutions is emphasized. Our results not only include the previously known CPW solutions, but also provide a wide class of new solutions that is not known in the literature before. We find that late time curvature singularity is always developed for the solutions we obtained in this paper. This supports the generalized version of Tipler's theorem in higher dimensional supergravity.

  11. Broader Impacts of the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Bardeen, M.; Ruchti, R.

    2005-08-01

    Large-scale scientific endeavors such as the International Linear Collider Project can have a lasting impact on education and outreach to our society. The ILC will provide a discovery platform for frontier physical science and it will also provide a discovery platform for broader impacts and social science. The importance of Broader Impacts of Science in general and the ILC in particular are described. Additionally, a synopsis of education and outreach activities carried out as an integral part of the Snowmass ILC Workshop is provided.

  12. SUSY Without Prejudice at Linear Colliders

    CERN Document Server

    Rizzo, Thomas G

    2008-01-01

    We explore the physics of the general CP-conserving MSSM with Minimal Flavor Violation, the pMSSM. The 19 soft SUSY breaking parameters are chosen so to satisfy all existing experimental and theoretical constraints assuming that the WIMP is the lightest neutralino. We scan this parameter space twice using both flat and log priors and compare the results which yield similar conclusions. Constraints from both LEP and the Tevatron play an important role in obtaining our final model samples. Implications for future TeV-scale $e^+e^-$ linear colliders(LC) are discussed.

  13. Measuring supersymmetry at the large hadron collider

    Indian Academy of Sciences (India)

    B C Allanach

    2003-02-01

    The large hadron collider (LHC) should have the ability to detect supersymmetric particles if low-energy supersymmetry solves the hierarchy problem. Studies of the LHC detection reach, and the ability to measure properties of supersymmetric particles are currently underway. We highlight some of these, such as the reach in minimal supergravity space and correlation with a fine-tuning parameter, precision measurements of edge variables, anomaly- or gauge-mediated supersymmetry breaking. Supersymmetry with baryon-number violation seems at first glance more difficult to detect, but proves to be possible by using leptons from cascade decays.

  14. NLC photon collider option progress and plans

    Energy Technology Data Exchange (ETDEWEB)

    Gronberg, J

    2000-08-31

    The idea of producing beams of high energy photons by Compton backscattering of laser photons was proposed over 20 years ago. At the time, producing the required laser pulses was not feasible. However, recent advances in high average power, diode pumped lasers appear to have solved this problem. The US Collaboration is now turning its attention to the engineering requirement of mating the laser and optics components with the accelerator structures in the confined space of the a colliding beam interaction region. The demonstration of a technically feasible interaction region design is planned for the Snowmass conference in 2001.

  15. Drell-Yan production at collider energies

    Energy Technology Data Exchange (ETDEWEB)

    Neerven, W.L. Van [Univ. of Leiden (Netherlands)

    1995-07-01

    We present some results of the Drell-Yan cross sections d{sigma}/dm and {sigma}{sub tot} which includes the O ({alpha}{sub s}{sup 2}) contribution to the coefficient function. In particular we study the total cross section {sigma}{sub tot} for vector boson production and d{sigma}/dm for low invariant masses m of the lepton pairs at large hadron collider energies. This study includes a detailed discussion of the dependence of the cross sections on the chosen scheme ({bar M}S versus DIS) and the factorization scale.

  16. Reducing risk where tectonic plates collide

    Science.gov (United States)

    Gomberg, Joan S.; Ludwig, Kristin A.

    2017-06-19

    Most of the world’s earthquakes, tsunamis, landslides, and volcanic eruptions are caused by the continuous motions of the many tectonic plates that make up the Earth’s outer shell. The most powerful of these natural hazards occur in subduction zones, where two plates collide and one is thrust beneath another. The U.S. Geological Survey’s (USGS) “Reducing Risk Where Tectonic Plates Collide—A USGS Plan to Advance Subduction Zone Science” is a blueprint for building the crucial scientific foundation needed to inform the policies and practices that can make our Nation more resilient to subduction zone-related hazards.

  17. Rf power sources for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M.A.; Callin, R.S.; Caryotakis, G.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Farkas, Z.D.; Fowkes, W.R.; Hoag, H.A.; Feinstein, J.; Ko, K.; Koontz, R.F.; Kroll, N.M.; Lavine, T.L.; Lee, T.G.; Loew, G.A.; Miller, R.H.; Nelson, E.M.; Ruth, R.D.; Vlieks, A.E.; Wang, J.W.; Wilson, P.B. (Stanford Linear Accelerator Center, Menlo Park, CA (USA)); Boyd, J.K.; Houk, T.; Ryne, R.D.; Westenskow, G.A.; Yu, S.S. (Lawrence Live

    1990-06-01

    The next generation of linear colliders requires peak power sources of over 200 MW per meter at frequencies above 10 GHz at pulse widths of less than 100 nsec. Several power sources are under active development, including a conventional klystron with rf pulse compression, a relativistic klystron (RK) and a crossed-field amplifier. Power from one of these has energized a 0.5 meter two- section High Gradient Accelerator (HGA) and accelerated a beam at over 80 MeV meter. Results of tests with these experimental devices are presented here.

  18. Higgs physics at the Large Hadron Collider

    Indian Academy of Sciences (India)

    Rohini M Godbole

    2011-05-01

    In this talk I shall begin by summarizing the importance of the Higgs physics studies at the Large Hadron Collider (LHC). I shall then give a short description of the pre-LHC constraints on the Higgs mass and the theoretical predictions for the LHC along with a discussion of the current experimental results, ending with prospects in the near future at the LHC. I have added to the writeup, recent experimental results from the LHC which have become available since the time of the workshop.

  19. The next linear collider damping ring lattices

    Energy Technology Data Exchange (ETDEWEB)

    Wolski, Andrzej; Corlett, John N.

    2001-06-20

    We report on the lattice design of the Next Linear Collider (NLC) damping rings. The damping rings are required to provide low emittance electron and positron bunch trains to the NLC linacs, at a rate of 120 Hz. We present an optical design, based on a theoretical minimum emittance (TME) lattice, to produce the required normalized extracted beam emittances gex = 3 mm-mrad and gey = 0.02 mm mrad. An assessment of dynamic aperture and non-linear effects is given. The positron pre-damping ring, required to reduce the emittance of the positron beam such that it may be accepted by a main damping ring, is also described.

  20. Six-jet production at lepton colliders

    Science.gov (United States)

    Moretti, S.

    1999-04-01

    We study electron-positron annihilations into six jets at the parton level in perturbative Quantum Chromo-Dynamics (QCD), via the elementary processes ɛ +ɛ - → q q-gggg, ɛ +ɛ - → q q-q' q-' gg and ɛ +ɛ - → q q-q' q-'q″ q-″ , for massive quarks q, q' and q″ and massless gluons g. Several numerical results of phenomenological relevance are given, at three different collider energies and for a representative selection of jet clustering algorithms. We also present helicity amplitudes and colour factors needed for the tree-level calculation.

  1. LHC - Large Hadon Collider Exhibition LEPFest 2000

    CERN Multimedia

    2000-01-01

    The Large Hadron Collider (LHC) will accelerate two proton beams to an energy corresponding to about 7,000 times their mass (7000 GeV). The collision of the two beams reproduces the conditions in the Universe when it was about 10 -1 2 sec old. Many innovative techniques - such as cooling with superfluid helium, the extensive use of high temperature superconducting cables, the two-in-one design for super-conducting dipole magnets, and new ultra-high vacuum technologies - had to be developed to make its construc-tion possible.

  2. Monitoring the Restart of a High-Rate Wastewater Disposal Well in the Val d'Agri Oilfield (Italy)

    Science.gov (United States)

    De Gori, P.; Improta, L.; Moretti, M.; Colasanti, G.; Criscuoli, F.

    2015-12-01

    The Val d'Agri Quaternary basin in the Southern Apennine range of Italy hosts the largest inland oil field in Europe. Wastewater coming from the oil exploitation is re-injected by a high-rate disposal well into strongly fractured limestones of the hydrocarbon carbonate reservoir. Disposal activity has induced micro-seismicity since the beginning of injection in June 2006. Around 220 small magnitude events (ML Vulcanologia. The induced micro-seismicity illuminated a pre-existing high-angle fault located 1 km below the well. Since June 2006, wastewater has been re-injected with only short interruptions due acid stimulations. In January 2015 disposal activity was halted due to technical operations in the oil refinery and wastewater injection restarted after two weeks. We installed 5 short-period stations within 10 km of the disposal well to carefully monitor the re-start phase and the subsequent 3 months of disposal activity. This temporary network was complemented by stations of the National Seismic Network giving this final configuration:9 stations within 10 km of the well with the closest station 2 km apart, 13 stations within 20 km. Here we report on the preliminary analysis of the local earthquake recorded during the survey focusing on the events occurred in the injection area. The seismicity rate is compared with injection data.In spite of the dense network, we found that the rate of induced seismicity (both the number and energy of events) is very low when compared to the seismicity recorded during the first 5 years of injection activity carried out with comparable rate and pressure.

  3. Identification of the glycerol kinase gene and its role in diapause embryo restart and early embryo development of Artemia sinica.

    Science.gov (United States)

    Cheng, Cheng; Yao, Feng; Chu, Bing; Li, Xuejie; Liu, Yan; Wu, Yang; Mei, Yanli; Wang, Peisheng; Hou, Lin; Zou, Xiangyang

    2014-03-01

    Glycerol kinase (GK) catalyzes the rate-limiting step in glycerol utilization by transferring a phosphate from ATP to glycerol, yielding glycerol 3-phosphate, which is an important intermediate for both energy metabolism and glycerolipid production. Artemia sinica has an unusual diapause process under stress conditions of high salinity, low temperature and lack of food. In the process, diapause embryos of A. sinica (brine shrimp) accumulate high concentrations of glycerol as a cryoprotectant to prevent low temperature damage to embryos. Upon embryo restart, glycerol is converted into glucose and other carbohydrates. Therefore, GK plays an important role in the diapause embryo restart process. However, the role of GK in diapause termination of embryo development in A. sinica remains unknown. In the present study, a 2096 bp full-length cDNA of gk from A. sinica (As-gk) was obtained, encoding putative 551 amino acids, 60.6 kDa protein. As a crucial enzyme in glycerol uptake and metabolism, GK has been conserved structurally and functionally during evolution. The expression pattern of As-gk was investigated by quantitative real-time PCR and Western blotting. Expression locations of As-gk were analyzed using in situ hybridization. As-gk was widely distributed in the early embryo and several main parts of Artemia after differentiation. The expression of As-GK was also induced by stresses such as cold exposure and high salinity. This initial research into the expression pattern and stress response of GK in Artemia provides a sound basis for further understanding of the function and regulation of genes in early embryonic development in A. sinica and the stress response.

  4. Luminosity Limitations in Linear Colliders Based on Plasma Acceleration

    CERN Document Server

    Lebedev, Valeri; Nagaitsev, Sergei

    2016-01-01

    Particle acceleration in plasma creates a possibility of exceptionally high accelerating gradients and appears as a very attractive option for future linear electron-positron and/or photon-photon colliders. These high accelerating gradients were already demonstrated in a number of experiments. However, a linear collider requires exceptionally high beam brightness which still needs to be demonstrated. In this article we discuss major phenomena which limit the beam brightness of accelerated beam and, consequently, the collider luminosity.

  5. Probing anomalous Higgs couplings at an collider using unpolarised beams

    Indian Academy of Sciences (India)

    Debajyoti Choudhury; Mamta

    2007-11-01

    We examine the sensitivity of colliders (based on + - linear colliders of c.m. energy 500 GeV) to the anomalous couplings of the Higgs to -boson via the process - → . This has the advantage over + - collider in being able to dissociate vertex from . We are able to construct several dynamical variables which may be used to constrain the various couplings in the vertex.

  6. Beyond the Large Hadron Collider: a first look at cryogenics for CERN future circular colliders

    CERN Document Server

    Lebrun, Ph

    2015-01-01

    Following the first experimental discoveries at the Large Hadron Collider (LHC) and the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. The study, conducted with the collaborative participation of interested institutes world-wide, considers several options for very high energy hadron-hadron, electron-positron and hadron-electron colliders to be installed in a quasi-circular underground tunnel in the Geneva basin, with a circumference of 80 km to 100 km. All these machines would make intensive use of advanced superconducting devices, i.e. high-field bending and focusing magnets and/or accelerating RF cavities, thus requiring large helium cryogenic systems operating at 4.5 K or below. Based on preliminary sets of parameters and layouts for the particle colliders under study, we discuss the main challenges of their cryogenic systems and present first estimates of the cryogenic refrigeration capacities req...

  7. Klystron switching power supplies for the Internation Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Fraioli, Andrea; /Cassino U. /INFN, Pisa

    2009-12-01

    The International Linear Collider is a majestic High Energy Physics particle accelerator that will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. ILC will complement the Large Hadron Collider (LHC), a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, by producing electron-positron collisions at center of mass energy of about 500 GeV. In particular, the subject of this dissertation is the R&D for a solid state Marx Modulator and relative switching power supply for the International Linear Collider Main LINAC Radio Frequency stations.

  8. Muon colliders, frictional cooling and universal extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Greenwald, Daniel E.

    2011-07-20

    A muon collider combines the advantages of proton-proton and electron-positron colliders, sidestepping many of their disadvantages, and has the potential to make discoveries and precision measurements at high energies. However, muons bring their own technical challenges, largely relating to their instability. We present a summary of the motivations and R and D efforts for a muon collider. We detail a scheme for preparing high-luminosity muon beams on timescales shorter than the muon lifetime, and an experiment to demonstrate aspects of this scheme at the Max Planck Institute for Physics. We also investigate the potentials to discover physics beyond the standard model at a muon collider. (orig.)

  9. Far Future Colliders and Required R&D Program

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V.; /Fermilab

    2012-06-01

    Particle colliders for high energy physics have been in the forefront of scientific discoveries for more than half a century. The accelerator technology of the collider has progressed immensely, while the beam energy, luminosity, facility size and the cost have grown by several orders of magnitude. The method of colliding beams has not fully exhausted its potential but its pace of progress has greatly slowed down. In this paper we very briefly review the R&D toward near future colliders and make an attempt to look beyond the current horizon and outline the changes in the paradigm required for the next breakthroughs.

  10. Comparing Tsallis and Boltzmann temperatures from relativistic heavy ion collider and large hadron collider heavy-ion data

    Science.gov (United States)

    Gao, Y.-Q.; Liu, F.-H.

    2016-03-01

    The transverse momentum spectra of charged particles produced in Au + Au collisions at the relativistic heavy ion collider and in Pb + Pb collisions at the large hadron collider with different centrality intervals are described by the multisource thermal model which is based on different statistic distributions for a singular source. Each source in the present work is described by the Tsallis distribution and the Boltzmann distribution, respectively. Then, the interacting system is described by the (two-component) Tsallis distribution and the (two-component) Boltzmann distribution, respectively. The results calculated by the two distributions are in agreement with the experimental data of the Solenoidal Tracker At Relativistic heavy ion collider, Pioneering High Energy Nuclear Interaction eXperiment, and A Large Ion Collider Experiment Collaborations. The effective temperature parameters extracted from the two distributions on the descriptions of heavy-ion data at the relativistic heavy ion collider and large hadron collider are obtained to show a linear correlation.

  11. Scaling Laws for $e^+ e^-$ Linear Colliders

    CERN Document Server

    Delahaye, J P; Raubenheimer, T O; Wilson, Ian H

    1999-01-01

    Design studies of a future TeV e+e- Linear Collider (TLC) are presently being made by five major laboratories within the framework of a world-wide collaboration. A figure of merit is defined which enables an objective comparison of these different designs. This figure of merit is shown to depend only on a small number of parameters. General scaling laws for the main beam parameters and linac parameters are derived and prove to be very effective when used as guidelines to optimize the linear collider design. By adopting appropriate parameters for beam stability, the figure of merit becomes nearly independent of accelerating gradient and RF frequency of the accelerating structures. In spite of the strong dependence of the wake-fields with frequency, the single bunch emittance preservation during acceleration along the linac is also shown to be independent of the RF frequency when using equivalent trajectory correction schemes. In this situation, beam acceleration using high frequency structures becomes very adv...

  12. Coherent bremsstrahlung at the HERA collider

    Energy Technology Data Exchange (ETDEWEB)

    Ginzberg, I.F. (Inst. of Mathematics, Novosibirsk (Russian Federation)); Kotkin, G.L. (Novosibirsk State Univ. (Russian Federation)); Polityko, S.I. (Irkutsk State Univ. (Russian Federation)); Serbo, V.G. (Irkutsk State Univ. (Russian Federation))

    1993-12-01

    We consider a new type of radiation at colliders with short bunches - coherent bremsstrahlung (CBS) which is the radiation of the first bunch particles caused by the collective electromagnetic field of the second bunch. The number of CBS photons for a single collision is dN[sub y][approx]N[sub 0]dE[sub y]/E[sub y] in the energy range E[sub y]< or [approx]E[sub c]=4y[sub 1][sup 2]hc/l[sub 2]. Here y[sub 1]=E[sub 1]/m[sub 1]c[sup 2]; l[sub 2] is the length of the opposing (second) bunch and N[sub 0] is proportional to N[sub 1]N[sub 2][sup 2] where N[sub j] is the j-th bunch population. For the HERA collider N[sub 0]=14, E[sub c]=73 eV in the case when photons are emitted by protons and N[sub 0]=6.10[sup 7], E[sub c]=24 keV - when photons are emitted by electrons. Unusual properties of such a coherent bremsstrahlung and the possibility to use CBS for fast beam steering and for luminosity optimization are discussed. (orig.)

  13. Physics motivations for a muon collider

    CERN Document Server

    Gunion, J F

    1996-01-01

    Future muon colliders will have remarkable capability for revealing and studying physics beyond the Standard Model. A first muon collider with variable c.m.\\ energy in the range \\sqrt s = 100 to 500~GeV provides unique opportunities for discovery and factory-like production of Higgs bosons in the s-channel. For excellent (but achievable) machine energy resolution, the total width and \\mupmum coupling of a SM-like Higgs boson with mass \\lsim 2\\mw (as particularly relevant to supersymmetric/GUT models) can be directly measured with substantial precision. Multiplication of measured branching ratios by the total width yields the corresponding couplings. As a result, the light CP-even SM-like Higgs of the minimal supersymmetric model can be distinguished from the Higgs of the minimal Standard Model over a larger portion of supersymmetric parameter space than otherwise possible. Scan discovery and detailed measurements of total widths and some partial widths of the heavier CP-even and CP-odd Higgs bosons of the min...

  14. Cooling of electronics in collider experiments

    Energy Technology Data Exchange (ETDEWEB)

    Richard P. Stanek et al.

    2003-11-07

    Proper cooling of detector electronics is critical to the successful operation of high-energy physics experiments. Collider experiments offer unique challenges based on their physical layouts and hermetic design. Cooling systems can be categorized by the type of detector with which they are associated, their primary mode of heat transfer, the choice of active cooling fluid, their heat removal capacity and the minimum temperature required. One of the more critical detector subsystems to require cooling is the silicon vertex detector, either pixel or strip sensors. A general design philosophy is presented along with a review of the important steps to include in the design process. Factors affecting the detector and cooling system design are categorized. A brief review of some existing and proposed cooling systems for silicon detectors is presented to help set the scale for the range of system designs. Fermilab operates two collider experiments, CDF & D0, both of which have silicon systems embedded in their detectors. A review of the existing silicon cooling system designs and operating experience is presented along with a list of lessons learned.

  15. Alignment Challenges for a Future Linear Collider

    CERN Document Server

    Durand, H; Stern, G

    2013-01-01

    The preservation of ultra-low emittances in the main linac and Beam Delivery System area is one of the main challenges for linear colliders. This requires alignment tolerances never achieved before at that scale, down to the micrometre level. As a matter of fact, in the LHC, the goal for the smoothing of the components was to obtain a 1σ deviation with respect to a smooth curve of 0.15 mm over a 150 m long sliding window, while for the CLIC project for example, it corresponds to 10 μm over a sliding window of 200 m in the Beam Delivery System area. Two complementary strategies are being studied to fulfil these requirements: the development and validation of long range alignment systems over a few hundreds of metres and short range alignment systems over a few metres. The studies undertaken, with associated tests setups and the latest results will be detailed, as well as their application for the alignment of both CLIC and ILC colliders.

  16. Searching for Top Squark at Hadron Colliders

    Institute of Scientific and Technical Information of China (English)

    YANG Jin-Min(杨金民); Young Bing-Lin

    2002-01-01

    In this talk we briefly summarise our recent study (hep-ph/0007165) on searching for top squark at hadron colliders. The light top-squark (stop) if produced in hadron colliders in the form of the t1t1 pair and decaying through the likely decay chain t1→X+b followed by X→X0ff′, can mimic closely a top quark event when the mass of the stop is close to that of the top quark. Because of the much lower production rate, the stop event can be buried under the top quark event sample. In order to uncover the stop event, specific selection cuts need to be applied. Through Monte Carlo simulation with suitable kinematic cuts, we found that such stop event can be extracted from the top quark sample and detected by the top counting experiments in the upcoming upgraded Tevatron and LHC. However, because of the small statistics of the Run 1 of the Tevatron, the stop signal remains hidden at Run 1.

  17. Physics at the Large Hadron Collider

    CERN Document Server

    Mukhopadhyaya, Biswarup; Raychaudhari, Amitava

    2009-01-01

    In an epoch when particle physics is awaiting a major step forward, the Large Hydron Collider (LHC) at CERN, Geneva will soon be operational. It will collide a beam of high energy protons with another similar beam circulation in the same 27 km tunnel but in the opposite direction, resulting in the production of many elementary particles some never created in the laboratory before. It is widely expected that the LHC will discover the Higgs boson, the particle which supposedly lends masses to all other fundamental particles. In addition, the question as to whether there is some new law of physics at such high energy is likely to be answered through this experiment. The present volume contains a collection of articles written by international experts, both theoreticians and experimentalists, from India and abroad, which aims to acquaint a non-specialist with some basic issues related to the LHC. At the same time, it is expected to be a useful, rudimentary companion of introductory exposition and technical expert...

  18. Ntuples for NLO Events at Hadron Colliders

    CERN Document Server

    Bern, Z.; Febres Cordero, F.; Höche, S.; Ita, H.; Kosower, D.A.; Maitre, D.

    2014-01-01

    We present an event-file format for the dissemination of next-to-leading-order (NLO) predictions for QCD processes at hadron colliders. The files contain all information required to compute generic jet-based infrared-safe observables at fixed order (without showering or hadronization), and to recompute observables with different factorization and renormalization scales. The files also make it possible to evaluate cross sections and distributions with different parton distribution functions. This in turn makes it possible to estimate uncertainties in NLO predictions of a wide variety of observables without recomputing the short-distance matrix elements. The event files allow a user to choose among a wide range of commonly-used jet algorithms and jet-size parameters. We provide event files for a $W$ or $Z$ boson accompanied by up to four jets, and for pure-jet events with up to four jets. The files are for the Large Hadron Collider with a center of mass energy of 7 or 8 TeV. A C++ library along with a Python in...

  19. ICOOL: A TOOL FOR MUON COLLIDER SIMULATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    FERNOW,R.C.

    2001-09-28

    Current ideas for designing neutrino factories [ 1,2] and muon colliders [3] require unique configurations of fields and materials to prepare the muon beam for acceleration. This so-called front end system must accomplish the goals of phase rotation, bunching and cooling. We have continued the development of a 3-D tracking code, ICOOL [4], for examining possible muon collider front end configurations. A system is described in terms of a series of longitudinal regions with associated material and field properties. The tracking takes place in a coordinate system that follows a reference orbit through the system. The code takes into account decays and interactions of {approx}50-500 MeV/c muons in matter. Material geometry regions include cylinders and wedges. A number of analytic models are provided for describing the field configurations. Simple diagnostics are built into the code, including calculation of emittances and correlations, longitudinal traces, histograms and scatter plots. A number of auxiliary codes can be used for pre-processing, post-processing and optimization.

  20. The Large Hadron Collider, a personal recollection

    CERN Document Server

    Evans, L

    2014-01-01

    The construction of the Large Hadron Collider (LHC) has been a massive endeavor spanning almost 30 years from conception to commissioning. Building the machine with the highest possible energy (7 TeV) in the existing LEP tunnel of 27 km circumference and with a tunnel diameter of only 3.8m has required considerable innovation. The first was the development of an idea first proposed by Bob Palmer at Brookhaven National Laboratory in 1978, where the two rings are integrated into a single magnetic structure. This compact 2-in-1 structure was essential for the LHC due to both the limited space available in the existing Large Electron-Positron collider tunnel and the cost. The second innovation was the bold move to use superfluid helium cooling on a massive scale, which was imposed by the need to achieve a high (8.3 T) magnetic field using an affordable Nb-Ti superconductor. In this article, no attempt is made to give a comprehensive review of the machine design. This can be found in the LHC Design Report {[}1], w...

  1. The Higgs Physics Programme at the International Linear Collider

    CERN Document Server

    Sefkow, Felix

    2014-01-01

    The talk summarises the case for Higgs physics in $e^+e^-$ collisions and explains how Higgs parameters can be extracted in a model-independent way at the International Linear Collider (ILC). The expected precision will be discussed in the context of projections for the experiments at the Large Hadron Collider (LHC).

  2. German lab unveils plan to build physicists' next collider

    CERN Multimedia

    Abott, A

    2001-01-01

    An international team of physicists are to propose the construction of a major collider. 'TESLA' - the 'Tera electron volt Energy Superconducting Linear Accelerator' will be a linear electron-positron collider based on superconducting resonators. It will be based at DESY and cost around three billion US dollars (2 pages).

  3. Supersymmetry status and phenomenology at the Large Hadron Collider

    Indian Academy of Sciences (India)

    Alexander Belyaev

    2009-01-01

    Large Hadron Collider (LHC) has a great chance to finally reveal supersymmetry which remains a compelling theory for over 30 years in spite of lack of its discovery. It might be around the corner the present LHC era with sensitive dark matter search experiments and international linear collider hopefully coming up in the near future.

  4. The Threshold of Embedded M Collider Bias and Confounding Bias

    Science.gov (United States)

    Kelcey, Benjamin; Carlisle, Joanne

    2011-01-01

    Of particular import to this study, is collider bias originating from stratification on retreatment variables forming an embedded M or bowtie structural design. That is, rather than assume an M structural design which suggests that "X" is a collider but not a confounder, the authors adopt what they consider to be a more reasonable…

  5. A Computation in a Cellular Automaton Collider Rule 110

    CERN Document Server

    Martinez, Genaro J; McIntosh, Harold V

    2016-01-01

    A cellular automaton collider is a finite state machine build of rings of one-dimensional cellular automata. We show how a computation can be performed on the collider by exploiting interactions between gliders (particles, localisations). The constructions proposed are based on universality of elementary cellular automaton rule 110, cyclic tag systems, supercolliders, and computing on rings.

  6. The Structure of Jets at Hadron Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Larkoski, Andrew James [Stanford Univ., CA (United States)

    2012-08-01

    Particle physics seeks to understand the interactions and properties of the fundamental particles. To gain understanding, there is an interplay between theory and experiment. Models are proposed to explain how particles behave and interact. These models make precise predictions that can be tested. Experiments are built and executed to measure the properties of these particles, providing necessary tests for the theories that attempt to explain the realm of fundamental particles. However, there is also another level of interaction between theory and experiment; the development of new experiments demands the study of how particles will behave with respect to the measured observables toward the goal of understanding the details and idiosyncrasies of the measurements very well. Only once these are well-modeled and understood can one be con dent that the data that are measured is trustworthy. The modeling and interpretation of the physics of a proton collider, such as the LHC, is the main topic of this thesis.

  7. Illuminating new electroweak states at hadron colliders

    Science.gov (United States)

    Ismail, Ahmed; Izaguirre, Eder; Shuve, Brian

    2016-07-01

    In this paper, we propose a novel powerful strategy to perform searches for new electroweak states. Uncolored electroweak states appear in generic extensions of the Standard Model (SM) and yet are challenging to discover at hadron colliders. This problem is particularly acute when the lightest state in the electroweak multiplet is neutral and all multiplet components are approximately degenerate. In this scenario, production of the charged fields of the multiplet is followed by decay into nearly invisible states; if this decay occurs promptly, the only way to infer the presence of the reaction is through its missing energy signature. Our proposal relies on emission of photon radiation from the new charged states as a means of discriminating the signal from SM backgrounds. We demonstrate its broad applicability by studying two examples: a pure Higgsino doublet and an electroweak quintuplet field.

  8. Colliding bodies optimization extensions and applications

    CERN Document Server

    Kaveh, A

    2015-01-01

    This book presents and applies a novel efficient meta-heuristic optimization algorithm called Colliding Bodies Optimization (CBO) for various optimization problems. The first part of the book introduces the concepts and methods involved, while the second is devoted to the applications. Though optimal design of structures is the main topic, two chapters on optimal analysis and applications in constructional management are also included.  This algorithm is based on one-dimensional collisions between bodies, with each agent solution being considered as an object or body with mass. After a collision of two moving bodies with specified masses and velocities, these bodies again separate, with new velocities. This collision causes the agents to move toward better positions in the search space.  The main algorithm (CBO) is internally parameter independent, setting it apart from previously developed meta-heuristics. This algorithm is enhanced (ECBO) for more efficient applications in the optimal design of structures...

  9. QCD and jets at hadron colliders

    Science.gov (United States)

    Sapeta, Sebastian

    2016-07-01

    We review various aspects of jet physics in the context of hadron colliders. We start by discussing the definitions and properties of jets and recent development in this area. We then consider the question of factorization for processes with jets, in particular for cases in which jets are produced in special configurations, like for example in the region of forward rapidities. We review numerous perturbative methods for calculating predictions for jet processes, including the fixed-order calculations as well as various matching and merging techniques. We also discuss the questions related to non-perturbative effects and the role they play in precision jet studies. We describe the status of calculations for processes with jet vetoes and we also elaborate on production of jets in forward direction. Throughout the article, we present selected comparisons between state-of-the-art theoretical predictions and the data from the LHC.

  10. QCD and Jets at Hadron Colliders

    CERN Document Server

    Sapeta, Sebastian

    2016-01-01

    We review various aspects of jet physics in the context of hadron colliders. We start by discussing the definitions and properties of jets and recent development in this area. We then consider the question of factorization for processes with jets, in particular for cases in which jets are produced in special configurations, like for example in the region of forward rapidities. We review numerous perturbative methods for calculating predictions for jet processes, including the fixed-order calculations as well as various matching and merging techniques. We also discuss the questions related to non-perturbative effects and the role they play in precision jet studies. We describe the status of calculations for processes with jet vetoes and we also elaborate on production of jets in forward direction. Throughout the article, we present selected comparisons between state-of-the-art theoretical predictions and the data from the LHC.

  11. Illuminating New Electroweak States at Hadron Colliders

    CERN Document Server

    Ismail, Ahmed; Shuve, Brian

    2016-01-01

    In this paper, we propose a novel powerful strategy to perform searches for new electroweak states. Uncolored electroweak states appear in generic extensions of the Standard Model (SM) and yet are challenging to discover at hadron colliders. This problem is particularly acute when the lightest state in the electroweak multiplet is neutral and all multiplet components are approximately degenerate. In this scenario, production of the charged fields of the multiplet is followed by decay into nearly invisible states; if this decay occurs promptly, the only way to infer the presence of the reaction is through its missing energy signature. Our proposal relies on emission of photon radiation from the new charged states as a means of discriminating the signal from SM backgrounds. We demonstrate its broad applicability by studying two examples: a pure Higgsino doublet and an electroweak quintuplet field.

  12. Indirect Collider Signals for Extra Dimensions

    CERN Document Server

    Hewett, J L

    1999-01-01

    A recent suggestion that quantum gravity may become strong near the weak scale has several testable consequences. In addition to probing for the new large (submillimeter) extra dimensions associated with these theories via gravitational experiments, one could search for the Kaluza Klein towers of massive gravitons which are predicted in these models and which can interact with the fields of the Standard Model. Here we examine the indirect effects of these massive gravitons being exchanged in fermion pair production in \\epem\\ annihilation and Drell-Yan production at hadron colliders. In the latter case, we examine a novel feature of this theory, which is the contribution of gluon gluon initiated processes to lepton pair production. We find that these processes provide strong bounds, up to several TeV, on the string scale which are essentially independent of the number of extra dimensions. In addition, we analyze the angular distributions for fermion pair production with spin-2 graviton exchanges and demonstrat...

  13. Genesis of the Large Hadron Collider.

    Science.gov (United States)

    Smith, Chris Llewellyn

    2015-01-13

    This paper describes the scientific, technical and political genesis of the Large Hadron Collider (LHC). It begins with an outline of the early history of the LHC, from first thoughts and accelerator and detector developments that underwrote the project, through the first studies of the LHC and its scientific potential and the genesis of the experimental programme, to the presentation of the proposal to build the LHC to the CERN Council in December 1993. The events that led to the proposal to build the LHC in two stages, which was approved in December 1994, are then described. Next, the role of non-Member State contributions and of the agreement that CERN could take loans, which allowed single stage construction to be approved in December 1996, despite a cut in the Members' contributions, are explained. The paper concludes by identifying points of potential relevance for the approval of possible future large particle physics projects.

  14. Galaxies Collide to Create Hot, Huge Galaxy

    Science.gov (United States)

    2009-01-01

    This image of a pair of colliding galaxies called NGC 6240 shows them in a rare, short-lived phase of their evolution just before they merge into a single, larger galaxy. The prolonged, violent collision has drastically altered the appearance of both galaxies and created huge amounts of heat turning NGC 6240 into an 'infrared luminous' active galaxy. A rich variety of active galaxies, with different shapes, luminosities and radiation profiles exist. These galaxies may be related astronomers have suspected that they may represent an evolutionary sequence. By catching different galaxies in different stages of merging, a story emerges as one type of active galaxy changes into another. NGC 6240 provides an important 'missing link' in this process. This image was created from combined data from the infrared array camera of NASA's Spitzer Space Telescope at 3.6 and 8.0 microns (red) and visible light from NASA's Hubble Space Telescope (green and blue).

  15. RF power generation for future linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fowkes, W.R.; Allen, M.A.; Callin, R.S.; Caryotakis, G.; Eppley, K.R.; Fant, K.S.; Farkas, Z.D.; Feinstein, J.; Ko, K.; Koontz, R.F.; Kroll, N.; Lavine, T.L.; Lee, T.G.; Miller, R.H.; Pearson, C.; Spalek, G.; Vlieks, A.E.; Wilson, P.B.

    1990-06-01

    The next linear collider will require 200 MW of rf power per meter of linac structure at relatively high frequency to produce an accelerating gradient of about 100 MV/m. The higher frequencies result in a higher breakdown threshold in the accelerating structure hence permit higher accelerating gradients per meter of linac. The lower frequencies have the advantage that high peak power rf sources can be realized. 11.42 GHz appears to be a good compromise and the effort at the Stanford Linear Accelerator Center (SLAC) is being concentrated on rf sources operating at this frequency. The filling time of the accelerating structure for each rf feed is expected to be about 80 ns. Under serious consideration at SLAC is a conventional klystron followed by a multistage rf pulse compression system, and the Crossed-Field Amplifier. These are discussed in this paper.

  16. Fragmentation of colliding planetesimals with water content

    CERN Document Server

    Maindl, Thomas I; Schäfer, Christoph; Speith, Roland

    2014-01-01

    We investigate the outcome of collisions of Ceres-sized planetesimals composed of a rocky core and a shell of water ice. These collisions are not only relevant for explaining the formation of planetary embryos in early planetary systems, but also provide insight into the formation of asteroid families and possible water transport via colliding small bodies. Earlier studies show characteristic collision velocities exceeding the bodies' mutual escape velocity which - along with the distribution of the impact angles - cover the collision outcome regimes 'partial accretion', 'erosion', and 'hit-and-run' leading to different expected fragmentation scenarios. Existing collision simulations use bodies composed of strengthless material; we study the distribution of fragments and their water contents considering the full elasto-plastic continuum mechanics equations also including brittle failure and fragmentation.

  17. Meeting of the Large Hadron Collider Committee

    CERN Multimedia

    2012-01-01

    Provisional Agenda for the 111th meeting of the Large Hadron Collider Committee to be held on Wednesday and Thursday, 26-27 September 2012. Open Session: Wednesday, 26 September at 9 a.m. in the Main Auditorium (Bldg. 500-1-001)  09.00 - 09.20    LHC Machine Status Report  09.30 - 10.00    ATLAS Status Report  10.10 - 10.40    CMS Status Report  10.50 - 11.10    COFFEE BREAK 11.10 - 11.40    LHCb Status Report 11.50 - 12.20   ALICE Status Report 12.30 - 12.50   TOTEM Status Report 13.00 - 13.20   LHCf Status Report

  18. Large Hadron Collider momentum calibration and accuracy

    CERN Document Server

    AUTHOR|(CDS)2051266; Todesco, Ezio

    2017-01-01

    As a result of the excellent quality of the Large Hadron Collider (LHC) experimental detectors and the accurate calibration of the luminosity at the LHC, uncertainties on the LHC beam energy may contribute significantly to the measurement errors on certain observables unless the relative uncertainty is well below 1%. Direct measurements of the beam energy using the revolution frequency difference of proton and lead beams combined with the magnetic model errors are used to provide the energy uncertainty of the LHC beams. Above injection energy the relative uncertainty on the beam energy is determined to be ±0.1%. The energy values as reconstructed and distributed online to the LHC experiments do not require any correction above injection energy. At injection a correction of +0.31 GeV/c must be applied to the online energy values.

  19. Large Hadron Collider momentum calibration and accuracy

    Science.gov (United States)

    Todesco, E.; Wenninger, J.

    2017-08-01

    As a result of the excellent quality of the Large Hadron Collider (LHC) experimental detectors and the accurate calibration of the luminosity at the LHC, uncertainties on the LHC beam energy may contribute significantly to the measurement errors on certain observables unless the relative uncertainty is well below 1%. Direct measurements of the beam energy using the revolution frequency difference of proton and lead beams combined with the magnetic model errors are used to provide the energy uncertainty of the LHC beams. Above injection energy the relative uncertainty on the beam energy is determined to be ±0.1 %. The energy values as reconstructed and distributed online to the LHC experiments do not require any correction above injection energy. At injection a correction of +0.31 GeV /c must be applied to the online energy values.

  20. A Large Hadron Electron Collider at CERN

    CERN Document Server

    Abelleira Fernandez, J L; Adzic, P; Akay, A N; Aksakal, H; Albacete, J L; Allanach, B; Alekhin, S; Allport, P; Andreev, V; Appleby, R B; Arikan, E; Armesto, N; Azuelos, G; Bai, M; Barber, D; Bartels, J; Behnke, O; Behr, J; Belyaev, A S; Ben-Zvi, I; Bernard, N; Bertolucci, S; Bettoni, S; Biswal, S; Blumlein, J; Bottcher, H; Bogacz, A; Bracco, C; Bracinik, J; Brandt, G; Braun, H; Brodsky, S; Bruning, O; Bulyak, E; Buniatyan, A; Burkhardt, H; Cakir, I T; Cakir, O; Calaga, R; Caldwell, A; Cetinkaya, V; Chekelian, V; Ciapala, E; Ciftci, R; Ciftci, A K; Cole, B A; Collins, J C; Dadoun, O; Dainton, J; Roeck, A.De; d'Enterria, D; DiNezza, P; Dudarev, A; Eide, A; Enberg, R; Eroglu, E; Eskola, K J; Favart, L; Fitterer, M; Forte, S; Gaddi, A; Gambino, P; Garcia Morales, H; Gehrmann, T; Gladkikh, P; Glasman, C; Glazov, A; Godbole, R; Goddard, B; Greenshaw, T; Guffanti, A; Guzey, V; Gwenlan, C; Han, T; Hao, Y; Haug, F; Herr, W; Herve, A; Holzer, B J; Ishitsuka, M; Jacquet, M; Jeanneret, B; Jensen, E; Jimenez, J M; Jowett, J M; Jung, H; Karadeniz, H; Kayran, D; Kilic, A; Kimura, K; Klees, R; Klein, M; Klein, U; Kluge, T; Kocak, F; Korostelev, M; Kosmicki, A; Kostka, P; Kowalski, H; Kraemer, M; Kramer, G; Kuchler, D; Kuze, M; Lappi, T; Laycock, P; Levichev, E; Levonian, S; Litvinenko, V N; Lombardi, A; Maeda, J; Marquet, C; Mellado, B; Mess, K H; Milanese, A; Milhano, J G; Moch, S; Morozov, I I; Muttoni, Y; Myers, S; Nandi, S; Nergiz, Z; Newman, P R; Omori, T; Osborne, J; Paoloni, E; Papaphilippou, Y; Pascaud, C; Paukkunen, H; Perez, E; Pieloni, T; Pilicer, E; Pire, B; Placakyte, R; Polini, A; Ptitsyn, V; Pupkov, Y; Radescu, V; Raychaudhuri, S; Rinolfi, L; Rizvi, E; Rohini, R; Rojo, J; Russenschuck, S; Sahin, M; Salgado, C A; Sampei, K; Sassot, R; Sauvan, E; Schaefer, M; Schneekloth, U; Schorner-Sadenius, T; Schulte, D; Senol, A; Seryi, A; Sievers, P; Skrinsky, A N; Smith, W; South, D; Spiesberger, H; Stasto, A M; Strikman, M; Sullivan, M; Sultansoy, S; Sun, Y P; Surrow, B; Szymanowski, L; Taels, P; Tapan, I; Tasci, T; Tassi, E; Kate, H.Ten; Terron, J; Thiesen, H; Thompson, L; Thompson, P; Tokushuku, K; Tomas Garcia, R; Tommasini, D; Trbojevic, D; Tsoupas, N; Tuckmantel, J; Turkoz, S; Trinh, T N; Tywoniuk, K; Unel, G; Ullrich, T; Urakawa, J; VanMechelen, P; Variola, A; Veness, R; Vivoli, A; Vobly, P; Wagner, J; Wallny, R; Wallon, S; Watt, G; Weiss, C; Wiedemann, U A; Wienands, U; Willeke, F; Xiao, B W; Yakimenko, V; Zarnecki, A F; Zhang, Z; Zimmermann, F; Zlebcik, R; Zomer, F; CERN. Geneva. LHeC Department

    2012-01-01

    This document provides a brief overview of the recently published report on the design of the Large Hadron Electron Collider (LHeC), which comprises its physics programme, accelerator physics, technology and main detector concepts. The LHeC exploits and develops challenging, though principally existing, accelerator and detector technologies. This summary is complemented by brief illustrations of some of the highlights of the physics programme, which relies on a vastly extended kinematic range, luminosity and unprecedented precision in deep inelastic scattering. Illustrations are provided regarding high precision QCD, new physics (Higgs, SUSY) and electron-ion physics. The LHeC is designed to run synchronously with the LHC in the twenties and to achieve an integrated luminosity of O(100) fb$^{-1}$. It will become the cleanest high resolution microscope of mankind and will substantially extend as well as complement the investigation of the physics of the TeV energy scale, which has been enabled by the LHC.

  1. Lepton Collider Operation With Constant Currents

    Energy Technology Data Exchange (ETDEWEB)

    Wienands, U.; /SLAC

    2006-02-22

    Electron-positron colliders have been operating in a top-up-and-coast fashion with a cycle time depending on the beam life time, typically one or more hours. Each top-up involves ramping detector systems in addition to the actual filling time. The loss in accumulated luminosity may be 20-50%. During the last year, both B-Factories have commissioned a continuous-injection mode of operation in which beam is injected without ramping the detector, thus raising luminosity integration by always operating at peak luminosity. Constant beam currents also reduce thermal drift and trips caused by change in beam loading. To achieve this level of operation, special efforts were made to reduce the injection losses and also to implement gating procedures in the detectors, minimizing dead time. Beam collimation can reduce injection noise but also cause an increase in background rates. A challenge can be determining beam lifetime, important to maintain tuning of the beams.

  2. Collide@CERN is looking for mentors

    CERN Multimedia

    2011-01-01

    The Collide@CERN Artist-in-Residence Programme is currently seeking CERN scientists interested in engaging in thought-provoking and creative collaborations with visiting artists.     In early 2012, a Digital artist will take up a 2-month residency and a Dance and Performance artist a 3-month residency.  Each artist will be allocated a specially selected science inspiration partner to work with. Both the artists and their mentors will give a public lecture in the Globe of Science and Innovation at the beginning and end of the residencies.  One scientist will be selected for each artist. Mentors and artists will be required to share knowledge by:   ·      Meeting once a week throughout the residency ·      Conducting online communications (such as a blog). If you are interested in becoming a mentor, please send the following information by e-m...

  3. A Proof of the Conformal Collider Bounds

    CERN Document Server

    Hofman, Diego M; Meltzer, David; Poland, David; Rejon-Barrera, Fernando

    2016-01-01

    In this paper, we prove that the "conformal collider bounds" originally proposed by Hofman and Maldacena hold for any unitary parity-preserving conformal field theory (CFT) with a unique stress tensor in spacetime dimensions larger than 2. In particular this implies that the ratio of central charges for a unitary 4d CFT lies in the interval $\\frac{31}{18} \\geq \\frac{a}{c} \\geq \\frac{1}{3}$. For superconformal theories this is further reduced to $\\frac{3}{2} \\geq \\frac{a}{c} \\geq \\frac{1}{2}$. The proof relies only on CFT first principles - in particular, bootstrap methods - and thus constitutes the first complete field theory proof of these bounds. We further elaborate on similar bounds for non-conserved currents and relate them to results obtained recently from deep inelastic scattering.

  4. The Right Delay

    NARCIS (Netherlands)

    Datadien, A.H.R.; Haselager, W.F.G.; Sprinkhuizen-Kuyper, I.G.

    2011-01-01

    Axonal conduction delays should not be ignored in simulations of spiking neural networks. Here it is shown that by using axonal conduction delays, neurons can display sensitivity to a specific spatio-temporal spike pattern. By using delays that complement the firing times in a pattern, spikes can ar

  5. The future of the Large Hadron Collider and CERN.

    Science.gov (United States)

    Heuer, Rolf-Dieter

    2012-02-28

    This paper presents the Large Hadron Collider (LHC) and its current scientific programme and outlines options for high-energy colliders at the energy frontier for the years to come. The immediate plans include the exploitation of the LHC at its design luminosity and energy, as well as upgrades to the LHC and its injectors. This may be followed by a linear electron-positron collider, based on the technology being developed by the Compact Linear Collider and the International Linear Collider collaborations, or by a high-energy electron-proton machine. This contribution describes the past, present and future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining key messages for the way forward.

  6. The future of the Large Hadron Collider and CERN

    CERN Document Server

    Heuer, Rolf-Dieter

    2012-01-01

    This paper presents the Large Hadron Collider (LHC) and its current scientific programme and outlines options for high-energy colliders at the energy frontier for the years to come. The immediate plans include the exploitation of the LHC at its design luminosity and energy, as well as upgrades to the LHC and its injectors. This may be followed by a linear electron–positron collider, based on the technology being developed by the Compact Linear Collider and the International Linear Collider collaborations, or by a high-energy electron–proton machine. This contribution describes the past, present and future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining key messages for the way forward.

  7. News from CERN, LHC Status and Strategy for Linear Colliders

    CERN Document Server

    Heuer, Rolf-Dieter

    2012-01-01

    This paper presents the latest development at CERN, concentrating on the status of the LHC and the strategy for future linear colliders. The immediate plans include the exploitation of the LHC at its design luminosity and energy as well as upgrades to the LHC (luminosity and energy) and to its injectors. This may be complemented by a linear electron-positron collider, based on the technology being developed by the Compact Linear Collider and by the International Linear Collider and/or by a high-energy electron-proton collider. This contribution describes the various future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining key messages for the way forward.

  8. Modeling of the re-starting of waxy crude oil flows in pipelines; Modelisation du redemarrage des ecoulements de bruts paraffiniques dans les conduites petrolieres

    Energy Technology Data Exchange (ETDEWEB)

    Vinay, G.

    2005-11-15

    Pipelining crude oils that contain large proportions of paraffins can cause many specific difficulties. These oils, known as waxy crude oils, usually exhibit high 'pour point', where this temperature is higher than the external temperature conditions surrounding the pipeline. During the shutdown, since the temperature decreases in the pipeline, the gel-like structure builds up and the main difficulty concerns the issue of restarting. This PhD attempts to improve waxy crude oil behaviour understanding thanks to experiment, modelling and numerical simulation in order to predict more accurately time and pressure required to restart the flow. Using various contributions to the literature, waxy crude oils are described as viscoplastic, thixotropic and compressible fluid. Strong temperature history dependence plays a prevailing role in the whole shutdown and restart process. Thus, waxy crude oils under flowing conditions correspond to the non-isothermal flow of a viscoplastic material with temperature-dependent rheological properties. Besides, the restart of a waxy crude oil is simulated by the isothermal transient flow of a weakly compressible thixotropic fluid in axisymmetric pipe geometry. We retain the Houska model to describe the thixotropic/viscoplastic feature of the fluid and compressibility is introduced in the continuity equation. The viscoplastic constitutive equation is involved using an augmented Lagrangian method and the resulting equivalent saddle-point problem is solved thanks to an Uzawa-like algorithm. Governing equations are discretized using a Finite Volume method and the convection terms are treated thanks to a TVD (Total Variation Diminishing) scheme. The Lagrangian functional technique usually used for incompressible viscoplastic flows, is adapted to compressible situations. Several numerical results attest the good convergence properties of the proposed transient algorithm. The non-isothermal results highlight the strong sensitivity of

  9. The Relativistic Heavy Ion Collider control system

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, T.S.; Barton, D.S.; Oerter, B.R.

    1997-12-01

    The Relativistic Heavy Ion Collider control system has been used in the commissioning of the AGS to RHIC transfer line and in the first RHIC sextant test. Much of the controls infrastructure for networks and links has been installed throughout the collider. All of the controls hardware modules needed to be built for early RHIC operations have been designed and tested. Many of these VME modules are already being used in normal AGS operations. Over 150 VME based front end computers and device controllers will be installed by the Summer of 1998 in order to be ready for Fall of 1998. A few features are being added to the front end computer core software. The bulk of the Accelerator Device Objects (ADOs) which are instantiated in the FECs, have been written and tested in the early commissioning. A configuration database has been designed. Generic control and display of ADO parameters via a spreadsheet like program on the console level computers was provided early on in the control system development. User interface tools that were developed for the AGS control system have been used in RHIC applications. Some of the basic operations programs, like alarm display and save/restore, that are used in the AGS operations have been or will be expanded to support RHIC operations. A model for application programs which involves a console level manager servicing ADOs have been verified with a few RHIC applications. More applications need to be written for the Fall of 1998 commissioning effort. A sequencer for automatic control of the fill is being written with the expectation that it will be useful in early commissioning.

  10. Linear Collider Flavour Identification status report: Sensors for the International Linear Collider

    Indian Academy of Sciences (India)

    K D Stefanov; for the Linear Collider Flavour Identification (LCFI) Collaboration

    2007-12-01

    The Linear Collider Flavour Identification (LCFI) collaboration is continuing the work to develop column-parallel CCDs (CPCCD) and CMOS readout chips to be used in the vertex detector at the international linear collider (ILC). The CPCCD achieves several orders of magnitude faster readout than conventional CCDs because every column is equipped with amplifier and ADC, enabling efficient data taking with low occupancy. Already two generations of CPCCDs and readout chips have been manufactured and the first chips have been fully tested. The second generation devices are now being evaluated. A new CCD-based device, the in-situ storage image sensor (ISIS) has also been developed. The ISIS offers numerous advantages in terms of relaxed readout, increased radiation hardness and great immunity to EMI. In this paper we present the results from the tests of the CPCCDs, readout chips and ISIS, as well as the plans for future developments.

  11. Colliding. gamma. e- and. gamma gamma. -beams on the basis of electron-positron linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, I.F.; Kotkin, G.L.; Serbo, V.G.; Tel' nov, V.I.

    1983-08-01

    Main properties of the ..gamma..e and ..gamma gamma.. collisions are discussed in some detail with application to the generation of colliding ..gamma..e and ..gamma gamma.. beams basing on the designed linear accelerators with colliding e/sup +/e/sup -/ beams, VLEEP and SLC, as it was proposed in a previous work. Intensive ..gamma.. beams with the energy 50 GeV would be produced from scattering of the laser light focused to the electron beams of the accelerators. Laser radiation is focused to the electron beam in the conversion region at a distance of about 10 cm from the place of collision. After scattering on electrons high-energy photons move practically along the electron primary trajectories and are focused in the collision region. The electrons are deflected from the collision region by means of approximately 1 T magnetic field. Then the produced ..gamma..-beam collides with an electron beam or a similar ..gamma..-beam. In the case when the maximum luminosity (L) is attained, the luminosity distribution in the invariant mass of the ..gamma..e or ..gamma gamma.. systems is wide. A monochromatization of the collisions up to the level of 5-10% is possible. That will entail a decrease in the luminosity, the procedure is most effective if one uses the electrons and the laser photons with opposite helicities. Examples of physically interesting problems to be investigated with the proposed ..gamma..e and ..gamma gamma.. beams are suggested.

  12. Sensitive assessment of the virologic outcomes of stopping and restarting non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy.

    Directory of Open Access Journals (Sweden)

    Anna Maria Geretti

    Full Text Available BACKGROUND: Non-nucleoside reverse transcriptase inhibitor (NNRTI-resistant mutants have been shown to emerge after interruption of suppressive NNRTI-based antiretroviral therapy (ART using routine testing. The aim of this study was to quantify the risk of resistance by sensitive testing and correlate the detection of resistance with NNRTI concentrations after treatment interruption and virologic responses after treatment resumption. METHODS: Resistance-associated mutations (RAMs and NNRTI concentrations were studied in plasma from 132 patients who interrupted suppressive ART within SMART. RAMs were detected by Sanger sequencing, allele-specific PCR, and ultra-deep sequencing. NNRTI concentrations were measured by sensitive high-performance liquid chromatography. RESULTS: Four weeks after NNRTI interruption, 19/31 (61.3% and 34/39 (87.2% patients showed measurable nevirapine (>0.25 ng/ml or efavirenz (>5 ng/ml concentrations, respectively. Median eight weeks after interruption, 22/131 (16.8% patients showed ≥1 NNRTI-RAM, including eight patients with NNRTI-RAMs detected only by sensitive testing. The adjusted odds ratio (OR of NNRTI-RAM detection was 7.62 (95% confidence interval [CI] 1.52, 38.30; p = 0.01 with nevirapine or efavirenz concentrations above vs. below the median measured in the study population. Staggered interruption, whereby nucleos(tide reverse transcriptase inhibitors (NRTIs were continued for median nine days after NNRTI interruption, did not prevent NNRTI-RAMs, but increased detection of NRTI-RAMs (OR 4.25; 95% CI 1.02, 17.77; p = 0.03. After restarting NNRTI-based ART (n = 90, virologic suppression rates <400 copies/ml were 8/13 (61.5% with NNRTI-RAMs, 7/11 (63.6% with NRTI-RAMs only, and 51/59 (86.4% without RAMs. The ORs of re-suppression were 0.18 (95% CI 0.03, 0.89 and 0.17 (95% CI 0.03, 1.15 for patients with NNRTI-RAMs or NRTI-RAMs only respectively vs. those without RAMs (p = 0.04. CONCLUSIONS

  13. An Analytical Delay Model

    Institute of Scientific and Technical Information of China (English)

    MIN Yinghua; LI Zhongcheng

    1999-01-01

    Delay consideration has been a majorissue in design and test of high performance digital circuits. Theassumption of input signal change occurring only when all internal nodesare stable restricts the increase of clock frequency. It is no longertrue for wave pipelining circuits. However, previous logical delaymodels are based on the assumption. In addition, the stable time of arobust delay test generally depends on the longest sensitizable pathdelay. Thus, a new delay model is desirable. This paper explores thenecessity first. Then, Boolean process to analytically describe thelogical and timing behavior of a digital circuit is reviewed. Theconcept of sensitization is redefined precisely in this paper. Based onthe new concept of sensitization, an analytical delay model isintroduced. As a result, many untestable delay faults under thelogical delay model can be tested if the output waveforms can be sampledat more time points. The longest sensitizable path length is computedfor circuit design and delay test.

  14. Identification, expression pattern and functional characterization of As-kip2 in diapause embryo restarting process of Artemia sinica.

    Science.gov (United States)

    Zhang, Mengchen; Yao, Feng; Qin, Tong; Hou, Lin; Zou, Xiangyang

    2017-04-15

    Proper control of the cellular processes requires a variety of regulatory proteins that are involved in the cell cycle, proliferation and apoptosis. Cyclin-dependent kinase inhibitor (CKI) negatively regulates transcription and arrests the cell cycle in G1 phase. KIP2 is a member of CKI family, which could inhibit proliferation by tight-binding with several cyclin-CDK complexes. During the embryonic development of the brine shrimp, Artemia sinica, KIP2 plays a key role in the cell cycle regulation, but the specific mechanisms remain unknown. Herein, the 1023bp full-length cDNA of kip2 from A. sinica was cloned. The mRNA expression patterns of As-kip2, As-carp-1 in different development stages and pattern of As-kip2 under environmental stresses were investigated. In situ hybridization of As-kip2 mRNA and immunofluorescence of As-CARP-1 protein showed no tissue or organ specificity. Furthermore, western blotting showed the expressions levels of As-KIP2, As-E2F1, As-p53, As-cyclin E, As-SODD protein, and pattern of As-KIP2 under environmental stresses. Our research revealed that As-KIP2 plays crucial role in the restarting process of diapause embryo in Artemia sinica. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Rebuilding Socio-Economic Cooperation in South East Europe and the Black Sea for Restarting European Integration

    Directory of Open Access Journals (Sweden)

    Grigoris Zarotiadis

    2015-11-01

    Full Text Available In our paper “Feraios Revised: Inter-Regional Trans-National Socioeconomic Cooperation in South and Eastern Europe”, published in International Relations and Diplomacy Journal (December 2014, we analyzed the prospects of an inter-regional cross-national cooperation (in economic, social and political patterns in South and Eastern Europe through the structural reorganization of the existing institutions (local, national or cross-national in the area and we expressed the need for the reintroduction of Rigas Feraios’ perspective of socioeconomic and ultimately of political integration in this region. The present paper is an attempt to explain the reasons why working on the regional socioeconomic cooperation and integration constitutes a necessary condition before going into a wider amalgamation. Contemporary systemic, global crisis brought out internal and transnational aberrations and the fact of the asymmetrical financial integration of the EU countries. The Union consists of a multilevel system were social conflicts, different rates of economic development and various demographic dynamics dominate. The increasing territorial inequalities in the enlarged Europe and the “suspended step” of a monetary unification might establish the need to revert to regional socioeconomic cooperation, on the basis of the existing cultural, economic and historical bonds, like those of South-East Europe and the Black Sea, for restarting European integration and succeed inter-union stability and prosperity.

  16. PriC-mediated DNA replication restart requires PriC complex formation with the single-stranded DNA-binding protein.

    Science.gov (United States)

    Wessel, Sarah R; Marceau, Aimee H; Massoni, Shawn C; Zhou, Ruobo; Ha, Taekjip; Sandler, Steven J; Keck, James L

    2013-06-14

    Frequent collisions between cellular DNA replication complexes (replisomes) and obstacles such as damaged DNA or frozen protein complexes make DNA replication fork progression surprisingly sporadic. These collisions can lead to the ejection of replisomes prior to completion of replication, which, if left unrepaired, results in bacterial cell death. As such, bacteria have evolved DNA replication restart mechanisms that function to reload replisomes onto abandoned DNA replication forks. Here, we define a direct interaction between PriC, a key Escherichia coli DNA replication restart protein, and the single-stranded DNA-binding protein (SSB), a protein that is ubiquitously associated with DNA replication forks. PriC/SSB complex formation requires evolutionarily conserved residues from both proteins, including a pair of Arg residues from PriC and the C terminus of SSB. In vitro, disruption of the PriC/SSB interface by sequence changes in either protein blocks the first step of DNA replication restart, reloading of the replicative DnaB helicase onto an abandoned replication fork. Consistent with the critical role of PriC/SSB complex formation in DNA replication restart, PriC variants that cannot bind SSB are non-functional in vivo. Single-molecule experiments demonstrate that PriC binding to SSB alters SSB/DNA complexes, exposing single-stranded DNA and creating a platform for other proteins to bind. These data lead to a model in which PriC interaction with SSB remodels SSB/DNA structures at abandoned DNA replication forks to create a DNA structure that is competent for DnaB loading.

  17. Anaerobic treatment of tequila vinasses under seasonal operating conditions: start-up, normal operation and restart-up after a long stop and starvation period.

    Science.gov (United States)

    Jáuregui-Jáuregui, J A; Méndez-Acosta, H O; González-Álvarez, V; Snell-Castro, R; Alcaraz-González, V; Godon, J J

    2014-09-01

    This study examines the performance of an anaerobic fixed-film bioreactor under seasonal operating conditions prevailing in medium and small size Tequila factories: start-up, normal operation and particularly, during the restart-up after a long stop and starvation period. The proposed start-up procedure attained a stable biofilm in a rather short period (28 days) despite unbalanced COD/N/P ratio and the use of non-acclimated inoculum. The bioreactor was restarted-up after being shut down for 6 months during which the inoculum starved. Even when biofilm detachment and bioreactor clogging were detected at the very beginning of restart-up, results show that the bioreactor performed better as higher COD removal and methane yield were attained. CE-SSCP and Q-PCR analyses, conducted on the biofilm prokaryotic communities for each operating condition, confirmed that the high COD removal results after the bioreactor clogging and the severe starvation period were mainly due to the stable archaeal and resilient bacterial populations.

  18. Run scenarios for the linear collider

    Energy Technology Data Exchange (ETDEWEB)

    M. Battaglia et al.

    2002-12-23

    We have examined how a Linear Collider program of 1000 fb{sup -1} could be constructed in the case that a very rich program of new physics is accessible at {radical}s {le} 500 GeV. We have examined possible run plans that would allow the measurement of the parameters of a 120 GeV Higgs boson, the top quark, and could give information on the sparticle masses in SUSY scenarios in which many states are accessible. We find that the construction of the run plan (the specific energies for collider operation, the mix of initial state electron polarization states, and the use of special e{sup -}e{sup -} runs) will depend quite sensitively on the specifics of the supersymmetry model, as the decay channels open to particular sparticles vary drastically and discontinuously as the underlying SUSY model parameters are varied. We have explored this dependence somewhat by considering two rather closely related SUSY model points. We have called for operation at a high energy to study kinematic end points, followed by runs in the vicinity of several two body production thresholds once their location is determined by the end point studies. For our benchmarks, the end point runs are capable of disentangling most sparticle states through the use of specific final states and beam polarizations. The estimated sparticle mass precisions, combined from end point and scan data, are given in Table VIII and the corresponding estimates for the mSUGRA parameters are in Table IX. The precision for the Higgs boson mass, width, cross-sections, branching ratios and couplings are given in Table X. The errors on the top quark mass and width are expected to be dominated by the systematic limits imposed by QCD non-perturbative effects. The run plan devotes at least two thirds of the accumulated luminosity near the maximum LC energy, so that the program would be sensitive to unexpected new phenomena at high mass scales. We conclude that with a 1 ab{sup -1} program, expected to take the first 6-7 years

  19. Run scenarios for the linear collider

    Energy Technology Data Exchange (ETDEWEB)

    M. Battaglia et al.

    2002-12-23

    We have examined how a Linear Collider program of 1000 fb{sup -1} could be constructed in the case that a very rich program of new physics is accessible at {radical}s {le} 500 GeV. We have examined possible run plans that would allow the measurement of the parameters of a 120 GeV Higgs boson, the top quark, and could give information on the sparticle masses in SUSY scenarios in which many states are accessible. We find that the construction of the run plan (the specific energies for collider operation, the mix of initial state electron polarization states, and the use of special e{sup -}e{sup -} runs) will depend quite sensitively on the specifics of the supersymmetry model, as the decay channels open to particular sparticles vary drastically and discontinuously as the underlying SUSY model parameters are varied. We have explored this dependence somewhat by considering two rather closely related SUSY model points. We have called for operation at a high energy to study kinematic end points, followed by runs in the vicinity of several two body production thresholds once their location is determined by the end point studies. For our benchmarks, the end point runs are capable of disentangling most sparticle states through the use of specific final states and beam polarizations. The estimated sparticle mass precisions, combined from end point and scan data, are given in Table VIII and the corresponding estimates for the mSUGRA parameters are in Table IX. The precision for the Higgs boson mass, width, cross-sections, branching ratios and couplings are given in Table X. The errors on the top quark mass and width are expected to be dominated by the systematic limits imposed by QCD non-perturbative effects. The run plan devotes at least two thirds of the accumulated luminosity near the maximum LC energy, so that the program would be sensitive to unexpected new phenomena at high mass scales. We conclude that with a 1 ab{sup -1} program, expected to take the first 6-7 years

  20. Laser cooling of electron beams for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Telnov, V.

    1996-10-01

    A novel method of electron beam cooling is considered which can be used for linear colliders. The electron beam is cooled during collision with focused powerful laser pulse. With reasonable laser parameters (laser flash energy about 10 J) one can decrease transverse beam emittances by a factor about 10 per one stage. The ultimate transverse emittances are much below that given by other methods. Depolarization of a beam during the cooling is about 5--15% for one stage. This method is especially useful for photon colliders and open new possibilities for e{sup +}e{sup {minus}} colliders and x-ray FEL based on high energy linacs.

  1. The signatures of doubly charged leptons in future linear colliders

    Science.gov (United States)

    Guo, Yu-Chen; Yue, Chong-Xing; Liu, Zhi-Cheng

    2017-08-01

    We discuss the production of the doubly charged leptons in future linear electron positron colliders, such as the International Linear Collider and Compact Linear Collider. Such states are introduced in extended weak-isospin multiplets by composite models. We discuss the production cross section of {e}-γ \\to {L}--{W}+ and carry out analyses for hadronic, semi-leptonic and pure leptonic channels based on the full simulation performance of the silicon detector. The 3- and 5-sigma statistical significance exclusion curves are provided in the model parameter space. It is found that the hadronic channel could offer the most possible detectable signature.

  2. The signatures of doubly charged leptons in future linear colliders

    CERN Document Server

    Guo, Yu-Chen; Liu, Zhi-Cheng

    2016-01-01

    We discuss the production of the doubly charged leptons in future linear electron positron colliders, such as the International Linear Collider and Compact Linear Collider. Such states are introduced in extended weak-isospin multiplets by composite models. We discuss the production cross section of $e^-\\gamma\\rightarrow L^{--}W^{+}$ and carry out analyses for hadronic, semi-leptonic and pure leptonic channels based on the full simulation performance of the Silicon Detector. The 3- and 5-sigma statistical significance exclusion curves are provided in the model parameter space. It is found that the hadronic channel could offer the most possible detectable signature.

  3. TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

    Energy Technology Data Exchange (ETDEWEB)

    Jabeen, Shabnam

    2013-10-20

    This review summarizes the recent results for top quark and Higgs boson measurements from experiments at Tevatron, a proton–antiproton collider at a center-of-mass energy of √ s =1 . 96 TeV, and the Large Hadron Collider, a proton–proton collider at a center- of-mass energy of √ s = 7 TeV. These results include the discovery of a Higgs-like boson and measurement of its various properties, and measurements in the top quark sector, e.g. top quark mass, spin, charge asymmetry and production of single top quark.

  4. Proton-Proton and Proton-Antiproton Colliders

    CERN Document Server

    Scandale, Walter

    2014-01-01

    In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  5. Diphoton resonance at e+e- and photon colliders

    CERN Document Server

    Richard, F

    2016-01-01

    In this note, I will review the opportunities offered by the hint of a new resonance observed at LHC for future e+e- TeV linear collider projects. This discussion is mainly influenced by two specific scenarios of physics which assume either a (pseudo-)scalar or a tensor resonance, but these estimates can be used in most scenarios. I have assumed either a photon collider, which has a guaranteed signal with the LHC observation, or a standard e+e- collider, more straightforward to implement. Complementarity between LHC and LC measurements comes out as a firm conclusion.

  6. Intense ion-beam dynamics in the NICA collider

    Science.gov (United States)

    Kozlov, O. S.; Meshkov, I. N.; Sidorin, A. O.; Trubnikov, G. V.

    2016-12-01

    The problems of intense ion-beam dynamics in the developed and optimized optical structure of the NICA collider are considered. Conditions for beam collisions and obtaining the required parameters of luminosity in the operation energy range are discussed. The restriction on collider luminosity is related to effects of the domination of the space charge and intrabeam scattering. Applying methods of cooling, electron and stochastic ones, will permit one to suppress these effects and reach design luminosity. The work also deals with systems of magnetic field correction and problems of calculating the dynamic aperture of the collider.

  7. Proton-Proton and Proton-Antiproton Colliders

    Science.gov (United States)

    Scandale, Walter

    2015-02-01

    In the last five decades, proton-proton and proton-antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion-ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  8. Overview of Linear Collider Test Facilities and Results

    CERN Document Server

    Hayano, H

    2004-01-01

    Linear Collider technology will be recommended by the International Technology Recommendation Panel (ITRP) to the International Linear Collider Steering Committee (ILCSC), soon. Towards this recommendation, many efforts of the developments and the output results of each technology have been made to satisfy the requirements of the technical review committee report (TRC). The test facilities of each linear collider design are the place of the key technology demonstration and realization. The overview of the LC test facilities activities and outputs of TTF, NLCTA, ATF/GLCTA and CTF are summarized and reviewed.

  9. Collider Phenomenology of the 3-3-1 Model

    CERN Document Server

    Cao, Qing-Hong

    2016-01-01

    We study collider phenomenology of the so-called 331 model with $SU(3)_C\\otimes SU(3)_L\\otimes U(1)_X$ gauge structure at the large hadron collider, including single and double Higgs boson productions, Higgs boson rare decay, $Z^\\prime$ boson production, new charged gauge boson pair production, and heavy quark pair production. We discuss all the possible collider signatures of new particle productions. Four benchmark 331 models, $\\beta=\\pm \\sqrt{3}$ and $\\beta=\\pm 1/\\sqrt{3}$, are studied in this work.

  10. Tune variations in the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Aquilina, N. [CERN, Geneva (Switzerland); University of Malta, Msida (Malta); Giovannozzi, M.; Lamont, M. [CERN, Geneva (Switzerland); Sammut, N. [University of Malta, Msida (Malta); Steinhagen, R. [CERN, Geneva (Switzerland); Todesco, E., E-mail: ezio.todesco@cern.ch [CERN, Geneva (Switzerland); Wenninger, J. [CERN, Geneva (Switzerland)

    2015-04-01

    The horizontal and vertical betatron tunes of the Large Hadron Collider (LHC) mainly depend on the strength of the quadrupole magnets, but are also affected by the quadrupole component in the main dipoles. In case of systematic misalignments, the sextupole component from the main dipoles and sextupole corrector magnets also affect the tunes due to the feed down effect. During the first years of operation of the LHC, the tunes have been routinely measured and corrected through either a feedback or a feed forward system. In this paper, the evolution of the tunes during injection, ramp and flat top are reconstructed from the beam measurements and the settings of the tune feedback loop and of the feed forward corrections. This gives the obtained precision of the magnetic model of the machine with respect to quadrupole and sextupole components. Measurements at the injection plateau show an unexpected large decay whose origin is not understood. This data is discussed together with the time constants and the dependence on previous cycles. We present results of dedicated experiments that show that this effect does not originate from the decay of the main dipole component. During the ramp, the tunes drift by about 0.022. It is shown that this is related to the precision of tracking the quadrupole field in the machine and this effect is reduced to about 0.01 tune units during flat top.

  11. Z' Bosons at Colliders: a Bayesian Viewpoint

    CERN Document Server

    Erler, Jens; Munir, Shoaib; Rojas, Eduardo

    2011-01-01

    We revisit the CDF data on di-muon production to impose constraints on a large class of Z' bosons occurring in a variety of E_6 GUT based models. For this we suggest an alternative statistical analysis method which ultimately allows to straightforwardly (i) vary the gauge coupling strength, g', of the underlying U(1)'; (ii) include interference effects with the Z' amplitude (which are especially important for large g'); (iii) smoothly vary the U(1)' charges; (iv) combine these data with the electroweak precision constraints, as well as with other observables obtained from colliders such as LEP 2 and the LHC; and (v) find preferred regions in parameter space once an excess is seen. Our method yields limits generally differing by only a few percent from the CDF ones when we follow their approach. We also analyze the dependence of these limits on various factors contributing to the production cross-section, showing that currently systematic and theoretical uncertainties play a relatively minor role. One general ...

  12. Collider tests of (composite) diphoton resonances

    Science.gov (United States)

    Molinaro, Emiliano; Sannino, Francesco; Vignaroli, Natascia

    2016-10-01

    We analyze the Large Hadron Collider sensitivity to new pseudoscalar resonances decaying into diphoton with masses up to scales of few TeVs. We focus on minimal scenarios where the production mechanisms involve either photon or top-mediated gluon fusion, partially motivated by the tantalizing excess around 750 GeV reported by ATLAS and CMS. The two scenarios lead respectively to a narrow and a wide resonance. We first provide a model-independent analysis via effective operators and then introduce minimal models of composite dynamics where the diphoton channel is characterized by their topological sector. The relevant state here is the pseudoscalar associated with the axial anomaly of the new composite dynamics. If the Standard Model top mass is generated via four-fermion operators the coupling of this state to the top remarkably explains the wide-width resonance reported by ATLAS. Beyond the excess, our analysis paves the way to test dynamical electroweak symmetry breaking via topological sectors.

  13. Luminosity Measurement at the Large Hadron Collider

    CERN Document Server

    Caron, B L; Pinfold, J L

    2006-01-01

    Two novel methods of measuring the luminosity delivered to the ATLAS Experiment at the CERN Large Hadron Collider experiments are presented. The production of $\\mu^{+}\\mu^{-}$ pair via two photon interactions and single $W^{\\pm}/Z^{0}$ boson production are evaluated as methods for the measurement and monitoring of the proton-proton luminosity at the LHC. The characteristics of the $\\mu^{+}\\mu^{-}$ pairs from coherent $\\gamma \\gamma$ interactions are examined for both matrix element and equivalent photon based monte carlo generators with subsequent simulation of the ATLAS detector effects. The application of specific kinematic and vertex fit requirements is shown to offer a strong method of isolating signal from background and in turn yield an accurate offline measurement of the delivered luminosity via the pure QED process. The choice of kinematic cuts is shown to reduce the overall uncertainty in the method by limiting the size of corrections to the two photon interaction cross section to the level of 1\\%. B...

  14. Transverse Diagnostics For High Energy Hadron Colliders

    CERN Document Server

    Castro Carballo, Maria Elena

    2007-01-01

    The Large Hadron Collider (LHC) is a circular synchrotron accelerator that will explore new Physics at the higher energies ever achieved, aiming to find the Higgs boson. The LHC is being built at CERN and by 2007 it will be ready to produce head-on collisions of protons at a centre-of-mass energy of 14 TeV. The employment of superconducting magnets for achieving high energies, the high luminosity required for physics, the limited dynamic aperture and the large energy stored in the beams will make the machine very challenging to operate, especially during the injection process and the energy ramp. Two particular problems will be a high sensitivity to beam losses and a relatively poor field quality requiring the use of many types of magnetic correction elements. This may lead to the inclusion of certain beam measurements in feedback loops, making special demands on the control system. The injection and acceleration of the LHC proton beams without particle losses and emittance blow up will require an accurate co...

  15. Lepton Collider Operation with Constant Currents

    CERN Document Server

    Wienands, Ulrich

    2005-01-01

    Traditionally, electron-positron colliders have been operating in a top-off-and-coast fashion with a cycle time depending on the beam life time, typically on the order of an hour. Each top-off involves ramping detector systems in addition to the actual filling time. The loss in accumulated luminosity is typically 20-50%. During the last year, both B-Factories have commissioned a continuous-injection mode of operation in which beam is injected without ramping the detector, thus raising luminosity integration by constant operation at peak luminosity. Constant beam currents reduce thermal drift and trips caused by change in beam loading. To achieve this level of operation, special efforts were made to reduce the injection losses and also to implement special gating procedures in the detectors, minimizing dead time. Bunch-injection control decides which bunch to inject into next while maintaining small charge variation between bunches. Beam collimation can reduce injection noise but also cause an increase in back...

  16. Strong Higgs Interactions at a Linear Collider

    CERN Document Server

    Contino, Roberto; Pappadopulo, Duccio; Rattazzi, Riccardo; Thamm, Andrea

    2014-01-01

    We study the impact of Higgs precision measurements at a high-energy and high-luminosity linear electron positron collider, such as CLIC or the ILC, on the parameter space of a strongly interacting Higgs boson. Some combination of anomalous couplings are already tightly constrained by current fits to electroweak observables. However, even small deviations in the cross sections of single and double Higgs production, or the mere detection of a triple Higgs final state, can help establish whether it is a composite state and whether or not it emerges as a pseudo-Nambu-Goldstone boson from an underlying broken symmetry. We obtain an estimate of the ILC and CLIC sensitivities on the anomalous Higgs couplings from a study of WW scattering and hh production which can be translated into a sensitivity on the compositeness scale 4\\pi f, or equivalently on the degree of compositeness \\xi=v^2/f^2. We summarize the current experimental constraints, from electroweak data and direct resonance searches, and the expected reach...

  17. Colliding Epidemics and the Rise of Cryptococcosis

    Directory of Open Access Journals (Sweden)

    Christina C. Chang

    2015-12-01

    Full Text Available Discovered more than 100 years ago as a human pathogen, the Cryptococcus neoformans–Cryptococcus gattii (C. neoformans–C. gattii complex has seen a large global resurgence in its association with clinical disease in the last 30 years. First isolated in fermenting peach juice, and identified as a human pathogen in 1894 in a patient with bone lesions, this environmental pathogen has now found niches in soil, trees, birds, and domestic pets. Cryptococcosis is well recognized as an opportunistic infection and was first noted to be associated with reticuloendothelial cancers in the 1950s. Since then, advances in transplant immunology, medical science and surgical techniques have led to increasing numbers of solid organ transplantations (SOT and hematological stem cell transplantations being performed, and the use of biological immunotherapeutics in increasingly high-risk and older individuals, have contributed to the further rise in cryptococcosis. Globally, however, the major driver for revivification of cryptococcosis is undoubtedly the HIV epidemic, particularly in Sub-Saharan Africa where access to care and antiretroviral therapy remains limited and advanced immunodeficiency, poverty and malnutrition remains the norm. As a zoonotic disease, environmental outbreaks of both human and animal cryptococcosis have been reported, possibly driven by climate change. This is best exemplified by the resurgence of C. gattii infection in Vancouver Island, Canada, and the Pacific Northwest of the United States since 1999. Here we describe how the colliding epidemics of HIV, transplantation and immunologics, climate change and migration have contributed to the rise of cryptococcosis.

  18. Conformal collider physics: Energy and charge correlations

    CERN Document Server

    Hofman, Diego M

    2008-01-01

    We study observables in a conformal field theory which are very closely related to the ones used to describe hadronic events at colliders. We focus on the correlation functions of the energies deposited on calorimeters placed at a large distance from the collision. We consider initial states produced by an operator insertion and we study some general properties of the energy correlation functions for conformal field theories. We argue that the small angle singularities of energy correlation functions are controlled by the twist of non-local light-ray operators with a definite spin. We relate the charge two point function to a particular moment of the parton distribution functions appearing in deep inelastic scattering. The one point energy correlation functions are characterized by a few numbers. For ${\\cal N}=1$ superconformal theories the one point function for states created by the R-current or the stress tensor are determined by the two parameters $a$ and $c$ characterizing the conformal anomaly. Demandin...

  19. Electron Lenses for the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio [Fermilab; Valishev, Alexander [Fermilab; Bruce, Roderik [CERN; Redaelli, Stefano [CERN; Rossi, Adriana [CERN; Salvachua, Belen [CERN

    2014-07-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. This project is moving towards a technical design in 2014, with the goal to build the devices in 2015-2017, after resuming LHC operations and re-assessing needs and requirements at 6.5 TeV. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles.

  20. The next linear collider damping ring complex

    Energy Technology Data Exchange (ETDEWEB)

    Corlett,J.; Atkinson,D.; De Santis,S.; Hartman, N.; Kennedy, K.; Li, D.; Marks, S.; Minamihara, Y.; Nishimura, H.; Pivi, M.; Reavill, D.; Rimmer, R.; Schlueter, R.; Wolski, A.; Anderson,S.; McKee,B.; Raubenheimer, T.; Ross, M.; Sheppard, J.C.

    2001-06-12

    We report progress on the design of the Next Linear Collider (NLC) Damping Rings complexes. The purpose of the damping rings is to provide low emittance electron and positron bunch trains to the NLC linacs, at a rate of 120 Hz. As an option to operate at the higher rate of 180 Hz, two 1.98 GeV main damping rings per beam are proposed, and one positron pre-damping ring. The main damping rings store up to 0.8 amp in 3 trains of 190 bunches each and have normalized extracted beam emittances {gamma}{var_epsilon}x = 3 mm-mrad and {gamma}{var_epsilon}y = 0.02 mm-mrad. The optical designs, based on a theoretical minimum emittance lattice (TME), are described, with an analysis of dynamic aperture and non-linear effects. Key subsystems and components are described, including the wiggler, the vacuum systems and photon stop design, and the higher-order-mode damped RF cavities. Impedance and instabilities are discussed.

  1. Cryogenics for the Large Hadron Collider

    CERN Document Server

    Lebrun, P

    1999-01-01

    The Large Hadron Collider (LHC), a 26.7 km circumference superconducting accelerator equipped with high-field magnets operating in superfluid helium below 1.9 K, has now fully entered construction at CERN, the European Laboratory for Particle Physics. The heart of the LHC cryogenic system is the quasi-isothermal magnet cooling scheme, in which flowing two-phase saturated superfluid helium removes the heat load from the 36'000 ton cold mass, immersed in some 400 m3 static pressurised superfluid helium. The LHC also makes use of supercritical helium for non-isothermal cooling of the beam screens which intercept most of the dynamic heat loads at higher temperature. Although not used in normal operation, liquid nitrogen will provide the source of refrigeration for precooling the machine. Refrigeration for the LHC is produced in eight large refrigerators, each with an equivalent capacity of about 18 kW at 4.5 K, completed by 1.8 K refrigeration units making use of several stages of hydrodynamic cold compressors. T...

  2. Cryogenics for the Large Hadron Collider

    CERN Document Server

    Lebrun, P

    2000-01-01

    The Large Hadron Collider (LHC), a 26.7 km circumference superconducting accelerator equipped with high-field magnets operating in superfluid helium below 1.9 K, has now fully entered construction at CERN, the European Laboratory for Particle Physics. The heart of the LHC cryogenic system is the quasi-isothermal magnet cooling scheme, in which flowing two-phase saturated superfluid helium removes the heat load from the 36000 ton cold mass, immersed in some 400 m/sup 3/ static pressurised superfluid helium. The LHC also makes use of supercritical helium for nonisothermal cooling of the beam screens which intercept most of the dynamic heat loads at higher temperature. Although not used in normal operation, liquid nitrogen will provide the source of refrigeration for precooling the machine. Refrigeration for the LHC is produced in eight large refrigerators, each with an equivalent capacity of about 18 kW at 4.5 K, completed by 1.8 K refrigeration units making use of several stages of hydrodynamic cold compressor...

  3. Luminosity Measurement at the Large Hadron Collider

    CERN Document Server

    Caron, B L; Pinfold, J L

    2006-01-01

    Two novel methods of measuring the luminosity delivered to the ATLAS Experiment at the CERN Large Hadron Collider experiments are presented. The production of $\\mu^{+}\\mu^{-}$ pair via two photon interactions and single $W^{\\pm}/Z^{0}$ boson production are evaluated as methods for the measurement and monitoring of the proton-proton luminosity at the LHC. The characteristics of the $\\mu^{+}\\mu^{-}$ pairs from coherent $\\gamma \\gamma$ interactions are examined for both matrix element and equivalent photon based monte carlo generators with subsequent simulation of the ATLAS detector effects. The application of specific kinematic and vertex fit requirements is shown to offer a strong method of isolating signal from background and in turn yield an accurate offline measurement of the delivered luminosity via the pure QED process. The choice of kinematic cuts is shown to reduce the overall uncertainty in the method by limiting the size of corrections to the two photon interaction cross section to the level of 1\\%. B...

  4. Vector boson pair production at hadron colliders

    CERN Document Server

    Adamson, K L

    2002-01-01

    We calculate the contribution of gluon-gluon induced processes to vector boson pair production at hadron colliders, specifically the production of WZ, W gamma and Z gamma pairs. We calculate the tree level processes gg -> WZqq-bqr, gg -> W gamma qq-bar and gg -> Z gamma qq-bar, and the one loop process gg -> Z gamma. We use the helicity method and include the decay of the W and Z bosons into leptons in the narrow width approximation. We include anomalous triple gauge couplings in all of our vector boson pair production calculations. In order to integrate over the qq-bar final state phase space we use an extended version of the subtraction method to NNLO and cancel collinear singularities explicitly. The general subtraction terms that are obtained apply to all vector boson pair production processes. Due to the large gluon density at low x, the gluon induced terms of vector boson pair production are expected to be the dominant NNLO QCD correction, relevant at LHC energies. However, we show that due to a cancell...

  5. Collider tests of (composite diphoton resonances

    Directory of Open Access Journals (Sweden)

    Emiliano Molinaro

    2016-10-01

    Full Text Available We analyze the Large Hadron Collider sensitivity to new pseudoscalar resonances decaying into diphoton with masses up to scales of few TeVs. We focus on minimal scenarios where the production mechanisms involve either photon or top-mediated gluon fusion, partially motivated by the tantalizing excess around 750 GeV reported by ATLAS and CMS. The two scenarios lead respectively to a narrow and a wide resonance. We first provide a model-independent analysis via effective operators and then introduce minimal models of composite dynamics where the diphoton channel is characterized by their topological sector. The relevant state here is the pseudoscalar associated with the axial anomaly of the new composite dynamics. If the Standard Model top mass is generated via four-fermion operators the coupling of this state to the top remarkably explains the wide-width resonance reported by ATLAS. Beyond the excess, our analysis paves the way to test dynamical electroweak symmetry breaking via topological sectors.

  6. Electron lenses for the large hadron collider

    CERN Document Server

    Stancari†, G; Bruce, R; Redaelli, S; Rossi, A; Salvachua Ferrando, B

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beamswhose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-bybunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beamcompensation, and for the demonstration of halo scrapingwith hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. A conceptual design was recently completed, and the project is moving towards a technical design in 2014–2015 for construction in 2015–2017, if needed, after resuming LHC operations and re-assessing collimation needs and requirements at 6.5 TeV. Because of the...

  7. Delayed emergence after anesthesia.

    Science.gov (United States)

    Tzabazis, Alexander; Miller, Christopher; Dobrow, Marc F; Zheng, Karl; Brock-Utne, John G

    2015-06-01

    In most instances, delayed emergence from anesthesia is attributed to residual anesthetic or analgesic medications. However, delayed emergence can be secondary to unusual causes and present diagnostic dilemmas. Data from clinical studies is scarce and most available published material is comprised of case reports. In this review, we summarize and discuss less common and difficult to diagnose reasons for delayed emergence and present cases from our own experience or reference published case reports/case series. The goal is to draw attention to less common reasons for delayed emergence, identify patient populations that are potentially at risk and to help anesthesiologists identifying a possible cause why their patient is slow to wake up.

  8. Design of beam optics for the future circular collider e+e- collider rings

    Science.gov (United States)

    Oide, K.; Aiba, M.; Aumon, S.; Benedikt, M.; Blondel, A.; Bogomyagkov, A.; Boscolo, M.; Burkhardt, H.; Cai, Y.; Doblhammer, A.; Haerer, B.; Holzer, B.; Jowett, J. M.; Koop, I.; Koratzinos, M.; Levichev, E.; Medina, L.; Ohmi, K.; Papaphilippou, Y.; Piminov, P.; Shatilov, D.; Sinyatkin, S.; Sullivan, M.; Wenninger, J.; Wienands, U.; Zhou, D.; Zimmermann, F.

    2016-11-01

    A beam optics scheme has been designed for the future circular collider-e+e- (FCC-ee). The main characteristics of the design are: beam energy 45 to 175 GeV, 100 km circumference with two interaction points (IPs) per ring, horizontal crossing angle of 30 mrad at the IP and the crab-waist scheme [P. Raimondi, D. Shatilov, and M. Zobov, arXiv:physics/0702033; P. Raimondi, M. Zobov, and D. Shatilov, in Proceedings of the 22nd Particle Accelerator Conference, PAC-2007, Albuquerque, NM (IEEE, New York, 2007), p. TUPAN037.] with local chromaticity correction. The crab-waist scheme is implemented within the local chromaticity correction system without additional sextupoles, by reducing the strength of one of the two sextupoles for vertical chromatic correction at each side of the IP. So-called "tapering" of the magnets is applied, which scales all fields of the magnets according to the local beam energy to compensate for the effect of synchrotron radiation (SR) loss along the ring. An asymmetric layout near the interaction region reduces the critical energy of SR photons on the incoming side of the IP to values below 100 keV, while matching the geometry to the beam line of the FCC proton collider (FCC-hh) [A. Chancé et al., Proceedings of IPAC'16, 9-13 May 2016, Busan, Korea, TUPMW020 (2016).] as closely as possible. Sufficient transverse/longitudinal dynamic aperture (DA) has been obtained, including major dynamical effects, to assure an adequate beam lifetime in the presence of beamstrahlung and top-up injection. In particular, a momentum acceptance larger than ±2 % has been obtained, which is better than the momentum acceptance of typical collider rings by about a factor of 2. The effects of the detector solenoids including their compensation elements are taken into account as well as synchrotron radiation in all magnets. The optics presented in this paper is a step toward a full conceptual design for the collider. A number of issues have been identified for further

  9. Large Hadron Collider slideshow shows future of physics

    CERN Multimedia

    Kramer, S E

    2007-01-01

    "The European organization for Nuclear Research (CERN) has been building the Large Hadron Collider for many years, but it's finally taking shape and prepping to operate at full power in 2008." (1/2 page)

  10. High Energy Accelerator and Colliding Beam User Group

    Energy Technology Data Exchange (ETDEWEB)

    Snow, G.A.; Skuja, A.

    1992-05-01

    This report discusses research in the following areas: the study of e{sup +}e{sup {minus}} interactions; Hadron collider physics at Fermilab; fixed target physics and particle physics of general interest; and, the solenoidal detector collaboration at SSCL.

  11. SPADs for Vertex Tracker detectors in Future Colliders

    CERN Document Server

    Vilella, E; Vila, A; Dieguez, A

    2015-01-01

    Physics aims at the future linear colliders impose such stringent requirements on detector systems that exceed those met by any previous technology. Amongst other novel technologies, SPADs (Single Photon Avalanche Diodes) detectors are being developed to track high energy particles at ILC (International Linear Collider) and CLIC (Compact LInear Collider). These sensors offer outstanding qualities, such as an extraordinary high sensitivity, ultra-fast response time and virtually infinite gain, in addition to compatibility with standard CMOS technologies. As a result, SPAD detectors enable the direct conversion of a single particle event onto a CMOS digital signal in the sub-nanosecond time scale, which leads to the possibility of single BX (bunch crossing) resolution at some particle colliders. However, SPAD detectors suffer from two main problems, namely the noise pulses generated by the sensor and the low fill-factor. The noise pulses worsen the detector occupancy, while the low fill-factor reduces the detec...

  12. The ATLAS Experiment at the CERN Large Hadron Collider

    Science.gov (United States)

    ATLAS Collaboration; Aad, G.; Abat, E.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B. A.; Abolins, M.; Abramowicz, H.; Acerbi, E.; Acharya, B. S.; Achenbach, R.; Ackers, M.; Adams, D. L.; Adamyan, F.; Addy, T. N.; Aderholz, M.; Adorisio, C.; Adragna, P.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahmed, H.; Aielli, G.; Åkesson, P. F.; Åkesson, T. P. A.; Akimov, A. V.; Alam, S. M.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Aleppo, M.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alimonti, G.; Aliyev, M.; Allport, P. P.; Allwood-Spiers, S. E.; Aloisio, A.; Alonso, J.; Alves, R.; Alviggi, M. G.; Amako, K.; Amaral, P.; Amaral, S. P.; Ambrosini, G.; Ambrosio, G.; Amelung, C.; Ammosov, V. V.; Amorim, A.; Amram, N.; Anastopoulos, C.; Anderson, B.; Anderson, K. J.; Anderssen, E. C.; Andreazza, A.; Andrei, V.; Andricek, L.; Andrieux, M.-L.; Anduaga, X. S.; Anghinolfi, F.; Antonaki, A.; Antonelli, M.; Antonelli, S.; Apsimon, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Archambault, J. P.; Arguin, J.-F.; Arik, E.; Arik, M.; Arms, K. E.; Armstrong, S. R.; Arnaud, M.; Arnault, C.; Artamonov, A.; Asai, S.; Ask, S.; Åsman, B.; Asner, D.; Asquith, L.; Assamagan, K.; Astbury, A.; Athar, B.; Atkinson, T.; Aubert, B.; Auerbach, B.; Auge, E.; Augsten, K.; Aulchenko, V. M.; Austin, N.; Avolio, G.; Avramidou, R.; Axen, A.; Ay, C.; Azuelos, G.; Baccaglioni, G.; Bacci, C.; Bachacou, H.; Bachas, K.; Bachy, G.; Badescu, E.; Bagnaia, P.; Bailey, D. C.; Baines, J. T.; Baker, O. K.; Ballester, F.; Baltasar Dos Santos Pedrosa, F.; Banas, E.; Banfi, D.; Bangert, A.; Bansal, V.; Baranov, S. P.; Baranov, S.; Barashkou, A.; Barberio, E. L.; Barberis, D.; Barbier, G.; Barclay, P.; Bardin, D. Y.; Bargassa, P.; Barillari, T.; Barisonzi, M.; Barnett, B. M.; Barnett, R. M.; Baron, S.; Baroncelli, A.; Barone, M.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Barrillon, P.; Barriuso Poy, A.; Barros, N.; Bartheld, V.; Bartko, H.; Bartoldus, R.; Basiladze, S.; Bastos, J.; Batchelor, L. E.; Bates, R. L.; Batley, J. R.; Batraneanu, S.; Battistin, M.; Battistoni, G.; Batusov, V.; Bauer, F.; Bauss, B.; Baynham, D. E.; Bazalova, M.; Bazan, A.; Beauchemin, P. H.; Beaugiraud, B.; Beccherle, R. B.; Beck, G. A.; Beck, H. P.; Becks, K. H.; Bedajanek, I.; Beddall, A. J.; Beddall, A.; Bednár, P.; Bednyakov, V. A.; Bee, C.; Behar Harpaz, S.; Belanger, G. A. N.; Belanger-Champagne, C.; Belhorma, B.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellachia, F.; Bellagamba, L.; Bellina, F.; Bellomo, G.; Bellomo, M.; Beltramello, O.; Belymam, A.; Ben Ami, S.; Ben Moshe, M.; Benary, O.; Benchekroun, D.; Benchouk, C.; Bendel, M.; Benedict, B. H.; Benekos, N.; Benes, J.; Benhammou, Y.; Benincasa, G. P.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Beretta, M.; Berge, D.; Bergeaas, E.; Berger, N.; Berghaus, F.; Berglund, S.; Bergsma, F.; Beringer, J.; Bernabéu, J.; Bernardet, K.; Berriaud, C.; Berry, T.; Bertelsen, H.; Bertin, A.; Bertinelli, F.; Bertolucci, S.; Besson, N.; Beteille, A.; Bethke, S.; Bialas, W.; Bianchi, R. M.; Bianco, M.; Biebel, O.; Bieri, M.; Biglietti, M.; Bilokon, H.; Binder, M.; Binet, S.; Bingefors, N.; Bingul, A.; Bini, C.; Biscarat, C.; Bischof, R.; Bischofberger, M.; Bitadze, A.; Bizzell, J. P.; Black, K. M.; Blair, R. E.; Blaising, J. J.; Blanch, O.; Blanchot, G.; Blocker, C.; Blocki, J.; Blondel, A.; Blum, W.; Blumenschein, U.; Boaretto, C.; Bobbink, G. J.; Bocci, A.; Bocian, D.; Bock, R.; Boehm, M.; Boek, J.; Bogaerts, J. A.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bondarenko, V. G.; Bonino, R.; Bonis, J.; Bonivento, W.; Bonneau, P.; Boonekamp, M.; Boorman, G.; Boosten, M.; Booth, C. N.; Booth, P. S. L.; Booth, P.; Booth, J. R. A.; Borer, K.; Borisov, A.; Borjanovic, I.; Bos, K.; Boscherini, D.; Bosi, F.; Bosman, M.; Bosteels, M.; Botchev, B.; Boterenbrood, H.; Botterill, D.; Boudreau, J.; Bouhova-Thacker, E. V.; Boulahouache, C.; Bourdarios, C.; Boutemeur, M.; Bouzakis, K.; Boyd, G. R.; Boyd, J.; Boyer, B. H.; Boyko, I. R.; Bozhko, N. I.; Braccini, S.; Braem, A.; Branchini, P.; Brandenburg, G. W.; Brandt, A.; Brandt, O.; Bratzler, U.; Braun, H. M.; Bravo, S.; Brawn, I. P.; Brelier, B.; Bremer, J.; Brenner, R.; Bressler, S.; Breton, D.; Brett, N. D.; Breugnon, P.; Bright-Thomas, P. G.; Brochu, F. M.; Brock, I.; Brock, R.; Brodbeck, T. J.; Brodet, E.; Broggi, F.; Broklova, Z.; Bromberg, C.; Brooijmans, G.; Brouwer, G.; Broz, J.; Brubaker, E.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruni, A.; Bruni, G.; Bruschi, M.; Buanes, T.; Buchanan, N. J.; Buchholz, P.; Budagov, I. A.; Büscher, V.; Bugge, L.; Buira-Clark, D.; Buis, E. J.; Bujor, F.; Buran, T.; Burckhart, H.; Burckhart-Chromek, D.; Burdin, S.; Burns, R.; Busato, E.; Buskop, J. J. F.; Buszello, K. P.; Butin, F.; Butler, J. M.; Buttar, C. M.; Butterworth, J.; Butterworth, J. M.; Byatt, T.; Cabrera Urbán, S.; Cabruja Casas, E.; Caccia, M.; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calderón Terol, D.; Callahan, J.; Caloba, L. P.; Caloi, R.; Calvet, D.; Camard, A.; Camarena, F.; Camarri, P.; Cambiaghi, M.; Cameron, D.; Cammin, J.; Campabadal Segura, F.; Campana, S.; Canale, V.; Cantero, J.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Caprio, M.; Caracinha, D.; Caramarcu, C.; Carcagno, Y.; Cardarelli, R.; Cardeira, C.; Cardiel Sas, L.; Cardini, A.; Carli, T.; Carlino, G.; Carminati, L.; Caron, B.; Caron, S.; Carpentieri, C.; Carr, F. S.; Carter, A. A.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Cascella, M.; Caso, C.; Castelo, J.; Castillo Gimenez, V.; Castro, N.; Castrovillari, F.; Cataldi, G.; Cataneo, F.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Caughron, S.; Cauz, D.; Cavallari, A.; Cavalleri, P.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerna, C.; Cernoch, C.; Cerqueira, A. S.; Cerri, A.; Cerutti, F.; Cervetto, M.; Cetin, S. A.; Cevenini, F.; Chalifour, M.; Chamizo llatas, M.; Chan, A.; Chapman, J. W.; Charlton, D. G.; Charron, S.; Chekulaev, S. V.; Chelkov, G. A.; Chen, H.; Chen, L.; Chen, T.; Chen, X.; Cheng, S.; Cheng, T. L.; Cheplakov, A.; Chepurnov, V. F.; Cherkaoui El Moursli, R.; Chesneanu, D.; Cheu, E.; Chevalier, L.; Chevalley, J. L.; Chevallier, F.; Chiarella, V.; Chiefari, G.; Chikovani, L.; Chilingarov, A.; Chiodini, G.; Chouridou, S.; Chren, D.; Christiansen, T.; Christidi, I. A.; Christov, A.; Chu, M. L.; Chudoba, J.; Chuguev, A. G.; Ciapetti, G.; Cicalini, E.; Ciftci, A. K.; Cindro, V.; Ciobotaru, M. D.; Ciocio, A.; Cirilli, M.; Citterio, M.; Ciubancan, M.; Civera, J. V.; Clark, A.; Cleland, W.; Clemens, J. C.; Clement, B. C.; Clément, C.; Clements, D.; Clifft, R. W.; Cobal, M.; Coccaro, A.; Cochran, J.; Coco, R.; Coe, P.; Coelli, S.; Cogneras, E.; Cojocaru, C. D.; Colas, J.; Colijn, A. P.; Collard, C.; Collins-Tooth, C.; Collot, J.; Coluccia, R.; Comune, G.; Conde Muiño, P.; Coniavitis, E.; Consonni, M.; Constantinescu, S.; Conta, C.; Conventi, F. A.; Cook, J.; Cooke, M.; Cooper-Smith, N. J.; Cornelissen, T.; Corradi, M.; Correard, S.; Corso-Radu, A.; Coss, J.; Costa, G.; Costa, M. J.; Costanzo, D.; Costin, T.; Coura Torres, R.; Courneyea, L.; Couyoumtzelis, C.; Cowan, G.; Cox, B. E.; Cox, J.; Cragg, D. A.; Cranmer, K.; Cranshaw, J.; Cristinziani, M.; Crosetti, G.; Cuenca Almenar, C.; Cuneo, S.; Cunha, A.; Curatolo, M.; Curtis, C. J.; Cwetanski, P.; Czyczula, Z.; D'Auria, S.; D'Onofrio, M.; Da Rocha Gesualdi Mello, A.; Da Silva, P. V. M.; Da Silva, R.; Dabrowski, W.; Dael, A.; Dahlhoff, A.; Dai, T.; Dallapiccola, C.; Dallison, S. J.; Dalmau, J.; Daly, C. H.; Dam, M.; Damazio, D.; Dameri, M.; Danielsen, K. M.; Danielsson, H. O.; Dankers, R.; Dannheim, D.; Darbo, G.; Dargent, P.; Daum, C.; Dauvergne, J. P.; David, M.; Davidek, T.; Davidson, N.; Davidson, R.; Dawson, I.; Dawson, J. W.; Daya, R. K.; De, K.; de Asmundis, R.; de Boer, R.; DeCastro, S.; DeGroot, N.; de Jong, P.; de La Broise, X.; DeLa Cruz-Burelo, E.; DeLa Taille, C.; DeLotto, B.; DeOliveira Branco, M.; DePedis, D.; de Saintignon, P.; DeSalvo, A.; DeSanctis, U.; DeSanto, A.; DeVivie DeRegie, J. B.; DeZorzi, G.; Dean, S.; Dedes, G.; Dedovich, D. V.; Defay, P. O.; Degele, R.; Dehchar, M.; Deile, M.; DelPapa, C.; DelPeso, J.; DelPrete, T.; Delagnes, E.; Delebecque, P.; Dell'Acqua, A.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delpierre, P.; Delruelle, N.; Delsart, P. A.; Deluca Silberberg, C.; Demers, S.; Demichev, M.; Demierre, P.; Demirköz, B.; Deng, W.; Denisov, S. P.; Dennis, C.; Densham, C. J.; Dentan, M.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K. K.; Dewhurst, A.; Di Ciaccio, A.; Di Ciaccio, L.; Di Domenico, A.; Di Girolamo, A.; Di Girolamo, B.; Di Luise, S.; Di Mattia, A.; Di Simone, A.; Diaz Gomez, M. M.; Diehl, E. B.; Dietl, H.; Dietrich, J.; Dietsche, W.; Diglio, S.; Dima, M.; Dindar, K.; Dinkespiler, B.; Dionisi, C.; Dipanjan, R.; Dita, P.; Dita, S.; Dittus, F.; Dixon, S. D.; Djama, F.; Djilkibaev, R.; Djobava, T.; do Vale, M. A. B.; Dobbs, M.; Dobinson, R.; Dobos, D.; Dobson, E.; Dobson, M.; Dodd, J.; Dogan, O. B.; Doherty, T.; Doi, Y.; Dolejsi, J.; Dolenc, I.; Dolezal, Z.; Dolgoshein, B. A.; Domingo, E.; Donega, M.; Dopke, J.; Dorfan, D. E.; Dorholt, O.; Doria, A.; Dos Anjos, A.; Dosil, M.; Dotti, A.; Dova, M. T.; Dowell, J. D.; Doyle, A. T.; Drake, G.; Drakoulakos, D.; Drasal, Z.; Drees, J.; Dressnandt, N.; Drevermann, H.; Driouichi, C.; Dris, M.; Drohan, J. G.; Dubbert, J.; Dubbs, T.; Duchovni, E.; Duckeck, G.; Dudarev, A.; Dührssen, M.; Dür, H.; Duerdoth, I. P.; Duffin, S.; Duflot, L.; Dufour, M.-A.; Dumont Dayot, N.; Duran Yildiz, H.; Durand, D.; Dushkin, A.; Duxfield, R.; Dwuznik, M.; Dydak, F.; Dzahini, D.; Díez Cornell, S.; Düren, M.; Ebenstein, W. L.; Eckert, S.; Eckweiler, S.; Eerola, P.; Efthymiopoulos, I.; Egede, U.; Egorov, K.; Ehrenfeld, W.; Eifert, T.; Eigen, G.; Einsweiler, K.; Eisenhandler, E.; Ekelof, T.; Eklund, L. M.; El Kacimi, M.; Ellert, M.; Elles, S.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Ely, R.; Emeliyanov, D.; Engelmann, R.; Engström, M.; Ennes, P.; Epp, B.; Eppig, A.; Epshteyn, V. S.; Ereditato, A.; Eremin, V.; Eriksson, D.; Ermoline, I.; Ernwein, J.; Errede, D.; Errede, S.; Escalier, M.; Escobar, C.; Espinal Curull, X.; Esposito, B.; Esteves, F.; Etienne, F.; Etienvre, A. I.; Etzion, E.; Evans, H.; Evdokimov, V. N.; Evtoukhovitch, P.; Eyring, A.; Fabbri, L.; Fabjan, C. W.; Fabre, C.; Faccioli, P.; Facius, K.; Fadeyev, V.; Fakhrutdinov, R. M.; Falciano, S.; Falleau, I.; Falou, A. C.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farrell, J.; Farthouat, P.; Fasching, D.; Fassi, F.; Fassnacht, P.; Fassouliotis, D.; Fawzi, F.; Fayard, L.; Fayette, F.; Febbraro, R.; Fedin, O. L.; Fedorko, I.; Feld, L.; Feldman, G.; Feligioni, L.; Feng, C.; Feng, E. J.; Fent, J.; Fenyuk, A. B.; Ferencei, J.; Ferguson, D.; Ferland, J.; Fernando, W.; Ferrag, S.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferrer, A.; Ferrer, M. L.; Ferrere, D.; Ferretti, C.; Ferro, F.; Fiascaris, M.; Fichet, S.; Fiedler, F.; Filimonov, V.; Filipčič, A.; Filippas, A.; Filthaut, F.; Fincke-Keeler, M.; Finocchiaro, G.; Fiorini, L.; Firan, A.; Fischer, P.; Fisher, M. J.; Fisher, S. M.; Flaminio, V.; Flammer, J.; Flechl, M.; Fleck, I.; Flegel, W.; Fleischmann, P.; Fleischmann, S.; Fleta Corral, C. 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A.; Mima, S.; Minaenko, A. A.; Minano, M.; Minashvili, I. A.; Mincer, A. I.; Mindur, B.; Mineev, M.; Mir, L. M.; Mirabelli, G.; Miralles Verge, L.; Misawa, S.; Miscetti, S.; Misiejuk, A.; Mitra, A.; Mitrofanov, G. Y.; Mitsou, V. A.; Miyagawa, P. S.; Miyazaki, Y.; Mjörnmark, J. U.; Mkrtchyan, S.; Mladenov, D.; Moa, T.; Moch, M.; Mochizuki, A.; Mockett, P.; Modesto, P.; Moed, S.; Mönig, K.; Möser, N.; Mohn, B.; Mohr, W.; Mohrdieck-Möck, S.; Moisseev, A. M.; Moles Valls, R. M.; Molina-Perez, J.; Moll, A.; Moloney, G.; Mommsen, R.; Moneta, L.; Monnier, E.; Montarou, G.; Montesano, S.; Monticelli, F.; Moore, R. W.; Moore, T. B.; Moorhead, G. F.; Moraes, A.; Morel, J.; Moreno, A.; Moreno, D.; Morettini, P.; Morgan, D.; Morii, M.; Morin, J.; Morley, A. K.; Mornacchi, G.; Morone, M.-C.; Morozov, S. V.; Morris, E. J.; Morris, J.; Morrissey, M. C.; Moser, H. G.; Mosidze, M.; Moszczynski, A.; Mouraviev, S. V.; Mouthuy, T.; Moye, T. H.; Moyse, E. J. W.; Mueller, J.; Müller, M.; Muijs, A.; Muller, T. R.; Munar, A.; Munday, D. J.; Murakami, K.; Murillo Garcia, R.; Murray, W. J.; Myagkov, A. G.; Myska, M.; Nagai, K.; Nagai, Y.; Nagano, K.; Nagasaka, Y.; Nairz, A. M.; Naito, D.; Nakamura, K.; Nakamura, Y.; Nakano, I.; Nanava, G.; Napier, A.; Nassiakou, M.; Nasteva, I.; Nation, N. R.; Naumann, T.; Nauyock, F.; Nderitu, S. K.; Neal, H. A.; Nebot, E.; Nechaeva, P.; Neganov, A.; Negri, A.; Negroni, S.; Nelson, C.; Nemecek, S.; Nemethy, P.; Nepomuceno, A. A.; Nessi, M.; Nesterov, S. Y.; Neukermans, L.; Nevski, P.; Newcomer, F. M.; Nichols, A.; Nicholson, C.; Nicholson, R.; Nickerson, R. B.; Nicolaidou, R.; Nicoletti, G.; Nicquevert, B.; Niculescu, M.; Nielsen, J.; Niinikoski, T.; Niinimaki, M. J.; Nikitin, N.; Nikolaev, K.; Nikolic-Audit, I.; Nikolopoulos, K.; Nilsen, H.; Nilsson, B. S.; Nilsson, P.; Nisati, A.; Nisius, R.; Nodulman, L. J.; Nomachi, M.; Nomoto, H.; Noppe, J.-M.; Nordberg, M.; Norniella Francisco, O.; Norton, P. R.; Novakova, J.; Nowak, M.; Nozaki, M.; Nunes, R.; Nunes Hanninger, G.; Nunnemann, T.; Nyman, T.; O'Connor, P.; O'Neale, S. W.; O'Neil, D. C.; O'Neill, M.; O'Shea, V.; Oakham, F. G.; Oberlack, H.; Obermaier, M.; Oberson, P.; Ochi, A.; Ockenfels, W.; Odaka, S.; Odenthal, I.; Odino, G. A.; Ogren, H.; Oh, S. H.; Ohshima, T.; Ohshita, H.; Okawa, H.; Olcese, M.; Olchevski, A. G.; Oliver, C.; Oliver, J.; Olivo Gomez, M.; Olszewski, A.; Olszowska, J.; Omachi, C.; Onea, A.; Onofre, A.; Oram, C. J.; Ordonez, G.; Oreglia, M. J.; Orellana, F.; Oren, Y.; Orestano, D.; Orlov, I. O.; Orr, R. S.; Orsini, F.; Osborne, L. S.; Osculati, B.; Osuna, C.; Otec, R.; Othegraven, R.; Ottewell, B.; Ould-Saada, F.; Ouraou, A.; Ouyang, Q.; Øye, O. K.; Ozcan, V. E.; Ozone, K.; Ozturk, N.; Pacheco Pages, A.; Padhi, S.; Padilla Aranda, C.; Paganis, E.; Paige, F.; Pailler, P. M.; Pajchel, K.; Palestini, S.; Palla, J.; Pallin, D.; Palmer, M. J.; Pan, Y. B.; Panikashvili, N.; Panin, V. N.; Panitkin, S.; Pantea, D.; Panuskova, M.; Paolone, V.; Paoloni, A.; Papadopoulos, I.; Papadopoulou, T.; Park, I.; Park, W.; Parker, M. A.; Parker, S.; Parkman, C.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pasqualucci, E.; Passardi, G.; Passeri, A.; Passmore, M. S.; Pastore, F.; Pastore, Fr; Pataraia, S.; Pate, D.; Pater, J. R.; Patricelli, S.; Pauly, T.; Pauna, E.; Peak, L. S.; Peeters, S. J. M.; Peez, M.; Pei, E.; Peleganchuk, S. V.; Pellegrini, G.; Pengo, R.; Pequenao, J.; Perantoni, M.; Perazzo, A.; Pereira, A.; Perepelkin, E.; Perera, V. J. O.; Perez Codina, E.; Perez Reale, V.; Peric, I.; Perini, L.; Pernegger, H.; Perrin, E.; Perrino, R.; Perrodo, P.; Perrot, G.; Perus, P.; Peshekhonov, V. D.; Petereit, E.; Petersen, J.; Petersen, T. C.; Petit, P. J. F.; Petridou, C.; Petrolo, E.; Petrucci, F.; Petti, R.; Pezzetti, M.; Pfeifer, B.; Phan, A.; Phillips, A. W.; Phillips, P. W.; Piacquadio, G.; Piccinini, M.; Pickford, A.; Piegaia, R.; Pier, S.; Pilcher, J. E.; Pilkington, A. D.; Pimenta Dos Santos, M. A.; Pina, J.; Pinfold, J. L.; Ping, J.; Pinhão, J.; Pinto, B.; Pirotte, O.; Placakyte, R.; Placci, A.; Plamondon, M.; Plano, W. G.; Pleier, M.-A.; Pleskach, A. V.; Podkladkin, S.; Podlyski, F.; Poffenberger, P.; Poggioli, L.; Pohl, M.; Polak, I.; Polesello, G.; Policicchio, A.; Polini, A.; Polychronakos, V.; Pomarede, D. M.; Pommès, K.; Ponsot, P.; Pontecorvo, L.; Pope, B. G.; Popescu, R.; Popovic, D. S.; Poppleton, A.; Popule, J.; Portell Bueso, X.; Posch, C.; Pospelov, G. E.; Pospichal, P.; Pospisil, S.; Postranecky, M.; Potrap, I. N.; Potter, C. J.; Poulard, G.; Pousada, A.; Poveda, J.; Prabhu, R.; Pralavorio, P.; Prasad, S.; Prast, J.; Prat, S.; Prata, M.; Pravahan, R.; Preda, T.; Pretzl, K.; Pribyl, L.; Price, D.; Price, L. E.; Price, M. J.; Prichard, P. M.; Prieur, D.; Primavera, M.; Primor, D.; Prokofiev, K.; Prosso, E.; Proudfoot, J.; Przysiezniak, H.; Puigdengoles, C.; Purdham, J.; Purohit, M.; Puzo, P.; Pylaev, A. N.; Pylypchenko, Y.; Qi, M.; Qian, J.; Qian, W.; Qian, Z.; Qing, D.; Quadt, A.; Quarrie, D. R.; Quayle, W. B.; Rabbers, J. J.; Radeka, V.; Rafi, J. M.; Ragusa, F.; Rahimi, A. M.; Rahm, D.; Raine, C.; Raith, B.; Rajagopalan, S.; Rajek, S.; Rammer, H.; Ramstedt, M.; Rangod, S.; Ratoff, P. N.; Raufer, T.; Rauscher, F.; Rauter, E.; Raymond, M.; Reads, A. L.; Rebuzzi, D.; Redlinger, G. R.; Reeves, K.; Rehak, M.; Reichold, A.; Reinherz-Aronis, E.; Reisinger, I.; Reljic, D.; Rembser, C.; Ren, Z.; Renaudin-Crepe, S. R. C.; Renkel, P.; Rensch, B.; Rescia, S.; Rescigno, M.; Resconi, S.; Resende, B.; Rewiersma, P.; Rey, J.; Rey-Campagnolle, M.; Rezaie, E.; Reznicek, P.; Richards, R. A.; Richer, J.-P.; Richter, R. H.; Richter, R.; Richter-Was, E.; Ridel, M.; Riegler, W.; Rieke, S.; Rijpstra, M.; Rijssenbeek, M.; Rimoldi, A.; Rios, R. R.; Riu Dachs, I.; Rivline, M.; Rivoltella, G.; Rizatdinova, F.; Robertson, S. H.; Robichaud-Veronneau, A.; Robins, S.; Robinson, D.; Robson, A.; Rochford, J. H.; Roda, C.; Rodier, S.; Roe, S.; Røhne, O.; Rohrbach, F.; Roldán, J.; Rolli, S.; Romance, J. B.; Romaniouk, A.; Romanov, V. M.; Romeo, G.; Roos, L.; Ros, E.; Rosati, S.; Rosenbaum, F.; Rosenbaum, G. A.; Rosenberg, E. I.; Rosselet, L.; Rossi, L. P.; Rossi, L.; Rotaru, M.; Rothberg, J.; Rottländer, I.; Rousseau, D.; Rozanov, A.; Rozen, Y.; Ruber, R.; Ruckert, B.; Rudolph, G.; Rühr, F.; Ruggieri, F.; Ruggiero, G.; Ruiz, H.; Ruiz-Martinez, A.; Rulikowska-Zarebska, E.; Rumiantsev, V.; Rumyantsev, L.; Runge, K.; Runolfsson, O.; Rusakovich, N. A.; Rust, D. R.; Rutherfoord, J. P.; Ruwiedel, C.; Ryabov, Y. F.; Ryadovikov, V.; Ryan, P.; Rybkine, G.; da Costa, J. Sá; Saavedra, A. F.; Saboumazrag, S.; F-W Sadrozinski, H.; Sadykov, R.; Sakamoto, H.; Sala, P.; Salamon, A.; Saleem, M.; Salihagic, D.; Salt, J.; Saltó Bauza, O.; Salvachúa Ferrando, B. M.; Salvatore, D.; Salzburger, A.; Sampsonidis, D.; Samset, B. H.; Sánchez Sánchez, C. A.; Sanchis Lozano, M. A.; Sanchis Peris, E.; Sandaker, H.; Sander, H. G.; Sandhoff, M.; Sandvoss, S.; Sankey, D. P. C.; Sanny, B.; Sansone, S.; Sansoni, A.; Santamarina Rios, C.; Santander, J.; Santi, L.; Santoni, C.; Santonico, R.; Santos, J.; Sapinski, M.; Saraiva, J. G.; Sarri, F.; Sasaki, O.; Sasaki, T.; Sasao, N.; Satsounkevitch, I.; Sauvage, D.; Sauvage, G.; Savard, P.; Savine, A. Y.; Savinov, V.; Savoy-Navarro, A.; Savva, P.; Saxon, D. H.; Says, L. P.; Sbarra, C.; Sbrissa, E.; Sbrizzi, A.; Scannicchio, D. A.; Schaarschmidt, J.; Schacht, P.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schaller, M.; Schamov, A. G.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Scherzer, M. I.; Schiavi, C.; Schick, H.; Schieck, J.; Schieferdecker, P.; Schioppa, M.; Schlager, G.; Schlenker, S.; Schlereth, J. L.; Schmid, P.; Schmidt, M. P.; Schmitt, C.; Schmitt, K.; Schmitz, M.; Schmücker, H.; Schoerner, T.; Scholte, R. C.; Schott, M.; Schouten, D.; Schram, M.; Schricker, A.; Schroff, D.; Schuh, S.; Schuijlenburg, H. W.; Schuler, G.; Schultes, J.; Schultz-Coulon, H.-C.; Schumacher, J.; Schumacher, M.; Schune, Ph; Schwartzman, A.; Schweiger, D.; Schwemling, Ph; Schwick, C.; Schwienhorst, R.; Schwierz, R.; Schwindling, J.; Scott, W. G.; Secker, H.; Sedykh, E.; Seguin-Moreau, N.; Segura, E.; Seidel, S. C.; Seiden, A.; Seixas, J. M.; Sekhniaidze, G.; Seliverstov, D. M.; Selldén, B.; Seman, M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Seuster, R.; Severini, H.; Sevior, M. E.; Sexton, K. A.; Sfyrla, A.; Shah, T. P.; Shan, L.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaver, L.; Shaw, C.; Shears, T. G.; Sherwood, P.; Shibata, A.; Shield, P.; Shilov, S.; Shimojima, M.; Shin, T.; Shiyakova, M.; Shmeleva, A.; Shoa, M.; Shochet, M. J.; Shupe, M. A.; Sicho, P.; Sidoti, A.; Siebel, A.; Siebel, M.; Siegrist, J.; Sijacki, D.; Silva, J.; Silverstein, S. B.; Simak, V.; Simic, Lj; Simion, S.; Simmons, B.; Simonyan, M.; Sinervo, P.; Sipica, V.; Siragusa, G.; Sisakyan, A. N.; Sivoklokov, S.; Sjölin, J.; Skubic, P.; Skvorodnev, N.; Slattery, P.; Slavicek, T.; Sliwa, K.; Sloan, T. J.; Sloper, J.; Smakhtin, V.; Small, A.; Smirnov, S. Yu; Smirnov, Y.; Smirnova, L.; Smirnova, O.; Smith, N. A.; Smith, B. C.; Smith, D. S.; Smith, J.; Smith, K. M.; Smith, B.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snow, S. W.; Snow, J.; Snuverink, J.; Snyder, S.; Soares, M.; Soares, S.; Sobie, R.; Sodomka, J.; Söderberg, M.; Soffer, A.; Solans, C. A.; Solar, M.; Sole, D.; Solfaroli Camillocci, E.; Solodkov, A. A.; Solov'yanov, O. V.; Soloviev, I.; Soluk, R.; Sondericker, J.; Sopko, V.; Sopko, B.; Sorbi, M.; Soret Medel, J.; Sosebee, M.; Sosnovtsev, V. V.; Sospedra Suay, L.; Soukharev, A.; Soukup, J.; Spagnolo, S.; Spano, F.; Speckmayer, P.; Spegel, M.; Spencer, E.; Spighi, R.; Spigo, G.; Spila, F.; Spiriti, E.; Spiwoks, R.; Spogli, L.; Spousta, M.; Sprachmann, G.; Spurlock, B.; St. Denis, R. D.; Stahl, T.; Staley, R. J.; Stamen, R.; Stancu, S. N.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stapnes, S.; Starchenko, E. A.; Staroba, P.; Stastny, J.; Staude, A.; Stavina, P.; Stavrianakou, M.; Stavropoulos, G.; Stefanidis, E.; Steffens, J. L.; Stekl, I.; Stelzer, H. J.; Stenzel, H.; Stewart, G.; Stewart, T. D.; Stiller, W.; Stockmanns, T.; Stodulski, M.; Stonjek, S.; Stradling, A.; Straessner, A.; Strandberg, J.; Strandlie, A.; Strauss, M.; Strickland, V.; Striegel, D.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Strong, J. A.; Stroynowski, R.; Stugu, B.; Stumer, I.; Su, D.; Subramania, S.; Suchkov, S. I.; Sugaya, Y.; Sugimoto, T.; Suk, M.; Sulin, V. V.; Sultanov, S.; Sun, Z.; Sundal, B.; Sushkov, S.; Susinno, G.; Sutcliffe, P.; Sutton, M. R.; Sviridov, Yu M.; Sykora, I.; Szczygiel, R. R.; Szeless, B.; Szymocha, T.; Sánchez, J.; Ta, D.; Taboada Gameiro, S.; Tadel, M.; Tafirout, R.; Taga, A.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Talby, M.; Talyshev, A.; Tamsett, M. C.; Tanaka, J.; Tanaka, K.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tanaka, Y.; Tappern, G. P.; Tapprogge, S.; Tarem, S.; Tarrade, F.; Tarrant, J.; Tartarelli, G.; Tas, P.; Tasevsky, M.; Tayalati, Y.; Taylor, F. E.; Taylor, G.; Taylor, G. N.; Taylor, R. P.; Tcherniatine, V.; Tegenfeldt, F.; Teixeira-Dias, P.; Ten Kate, H.; Teng, P. K.; Ter-Antonyan, R.; Terada, S.; Terron, J.; Terwort, M.; Teuscher, R. J.; Tevlin, C. M.; Thadome, J.; Thion, J.; Thioye, M.; Thomas, A.; Thomas, J. P.; Thomas, T. L.; Thomas, E.; Thompson, R. J.; Thompson, A. S.; Thun, R. P.; Tic, T.; Tikhomirov, V. O.; Tikhonov, Y. A.; Timm, S.; Timmermans, C. J. W. P.; Tipton, P.; Tique Aires Viegas, F. J.; Tisserant, S.; Titov, M.; Tobias, J.; Tocut, V. M.; Toczek, B.; Todorova-Nova, S.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tomasek, L.; Tomasek, M.; Tomasz, F.; Tomoto, M.; Tompkins, D.; Tompkins, L.; Toms, K.; Tonazzo, A.; Tong, G.; Tonoyan, A.; Topfel, C.; Topilin, N. D.; Torrence, E.; Torres Pais, J. G.; Toth, J.; Touchard, F.; Tovey, D. R.; Tovey, S. N.; Towndrow, E. F.; Trefzger, T.; Treichel, M.; Treis, J.; Tremblet, L.; Tribanek, W.; Tricoli, A.; Trigger, I. M.; Trilling, G.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trka, Z.; Trocmé, B.; Troncon, C.; C-L Tseng, J.; Tsiafis, I.; Tsiareshka, P. V.; Tsipolitis, G.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Turala, M.; Turk Cakir, I.; Turlay, E.; Tuts, P. M.; Twomey, M. S.; Tyndel, M.; Typaldos, D.; Tyrvainen, H.; Tzamarioudaki, E.; Tzanakos, G.; Ueda, I.; Uhrmacher, M.; Ukegawa, F.; Ullán Comes, M.; Unal, G.; Underwood, D. G.; Undrus, A.; Unel, G.; Unno, Y.; Urkovsky, E.; Usai, G.; Usov, Y.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valderanis, C.; Valenta, J.; Valente, P.; Valero, A.; Valkar, S.; Valls Ferrer, J. A.; Van der Bij, H.; van der Graaf, H.; van der Kraaij, E.; Van Eijk, B.; van Eldik, N.; van Gemmeren, P.; van Kesteren, Z.; van Vulpen, I.; Van Berg, R.; Vandelli, W.; Vandoni, G.; Vaniachine, A.; Vannucci, F.; Varanda, M.; Varela Rodriguez, F.; Vari, R.; Varnes, E. W.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vassilieva, L.; Vataga, E.; Vaz, L.; Vazeille, F.; Vedrine, P.; Vegni, G.; Veillet, J. J.; Vellidis, C.; Veloso, F.; Veness, R.; Veneziano, S.; Ventura, A.; Ventura, S.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vertogardov, L.; Vetterli, M. C.; Vichou, I.; Vickey, T.; Viehhauser, G. H. A.; Vigeolas, E.; Villa, M.; Villani, E. G.; Villate, J.; Villella, I.; Vilucchi, E.; Vincent, P.; Vincke, H.; Vincter, M. G.; Vinogradov, V. B.; Virchaux, M.; Viret, S.; Virzi, J.; Vitale, A.; Vivarelli, I.; Vives, R.; Vives Vaques, F.; Vlachos, S.; Vogt, H.; Vokac, P.; Vollmer, C. F.; Volpi, M.; Volpini, G.; von Boehn-Buchholz, R.; von der Schmitt, H.; von Toerne, E.; Vorobel, V.; Vorobiev, A. P.; Vorozhtsov, A. S.; Vorozhtsov, S. B.; Vos, M.; Voss, K. C.; Voss, R.; Vossebeld, J. H.; Vovenko, A. S.; Vranjes, N.; Vrba, V.; Vreeswijk, M.; Anh, T. Vu; Vuaridel, B.; Vudragovic, M.; Vuillemin, V.; Vuillermet, R.; Wänanen, A.; Wahlen, H.; Walbersloh, J.; Walker, R.; Walkowiak, W.; Wall, R.; Wallny, R. S.; Walsh, S.; Wang, C.; Wang, J. C.; Wappler, F.; Warburton, A.; Ward, C. P.; Warner, G. P.; Warren, M.; Warsinsky, M.; Wastie, R.; Watkins, P. M.; Watson, A. T.; Watts, G.; Waugh, A. T.; Waugh, B. M.; Weaverdyck, C.; Webel, M.; Weber, G.; Weber, J.; Weber, M.; Weber, P.; Weidberg, A. R.; Weilhammer, P. M.; Weingarten, J.; Weiser, C.; Wellenstein, H.; Wellisch, H. P.; Wells, P. S.; Wemans, A.; Wen, M.; Wenaus, T.; Wendler, S.; Wengler, T.; Wenig, S.; Wermes, N.; Werneke, P.; Werner, P.; Werthenbach, U.; Wheeler-Ellis, S. J.; Whitaker, S. P.; White, A.; White, M. J.; White, S.; Whittington, D.; Wicek, F.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiesmann, M.; Wiesmann, M.; Wijnen, T.; Wildauer, A.; Wilhelm, I.; Wilkens, H. G.; Williams, H. H.; Willis, W.; Willocq, S.; Wilmut, I.; Wilson, J. A.; Wilson, A.; Wingerter-Seez, I.; Winton, L.; Witzeling, W.; Wlodek, T.; Woehrling, E.; Wolter, M. W.; Wolters, H.; Wosiek, B.; Wotschack, J.; Woudstra, M. J.; Wright, C.; Wu, S. L.; Wu, X.; Wuestenfeld, J.; Wunstorf, R.; Xella-Hansen, S.; Xiang, A.; Xie, S.; Xie, Y.; Xu, G.; Xu, N.; Yamamoto, A.; Yamamoto, S.; Yamaoka, H.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, J. C.; Yang, S.; Yang, U. K.; Yang, Y.; Yang, Z.; Yao, W.-M.; Yao, Y.; Yarradoddi, K.; Yasu, Y.; Ye, J.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, H.; Yoshida, R.; Young, C.; Youssef, S. P.; Yu, D.; Yu, J.; Yu, M.; Yu, X.; Yuan, J.; Yurkewicz, A.; Zaets, V. G.; Zaidan, R.; Zaitsev, A. M.; Zajac, J.; Zajacova, Z.; Zalite, A. Yu; Zalite, Yo K.; Zanello, L.; Zarzhitsky, P.; Zaytsev, A.; Zdrazil, M.; Zeitnitz, C.; Zeller, M.; Zema, P. F.; Zendler, C.; Zenin, A. V.; Zenis, T.; Zenonos, Z.; Zenz, S.; Zerwas, D.; Zhang, H.; Zhang, J.; Zheng, W.; Zhang, X.; Zhao, L.; Zhao, T.; Zhao, X.; Zhao, Z.; Zhelezko, A.; Zhemchugov, A.; Zheng, S.; Zhichao, L.; Zhou, B.; Zhou, N.; Zhou, S.; Zhou, Y.; Zhu, C. G.; Zhu, H. Z.; Zhuang, X. A.; Zhuravlov, V.; Zilka, B.; Zimin, N. I.; Zimmermann, S.; Ziolkowski, M.; Zitoun, R.; Zivkovic, L.; Zmouchko, V. V.; Zobernig, G.; Zoccoli, A.; Zoeller, M. M.; Zolnierowski, Y.; Zsenei, A.; zur Nedden, M.; Zychacek, V.

    2008-08-01

    The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.

  13. The LHC as a Proton-Nucleus Collider

    CERN Document Server

    Carli, C

    2006-01-01

    Following its initial operation as a proton-proton (p-p) and heavy-ion (208Pb82+-208Pb82+) collider, the LHC is expected to operate as a p-Pb collider. Later it may collide protons with other lighter nuclei such as 40Ar18+ or 16O8+. We show how the existing proton and lead-ion injector chains may be efficiently operated in tandem to provide these hybrid collisions. The two-in-one magnet design of the LHC main rings imposes different revolution frequencies for the two beams in part of the magnetic cycle. We discuss and evaluate the consequences for beam dynamics and estimate the potential performance of the LHC as a proton-nucleus collider.

  14. Crab Waist collision scheme: a novel approach for particle colliders

    CERN Document Server

    Zobov, Mikhail

    2016-01-01

    A new concept of nonlinear focusing of colliding bunches, called Crab Waist (CW)collision scheme, has been proposed at LNF INFN. It has been successfully tested at the Italian lepton collider DAFNE in operational conditions providing luminosity for two different experimental detectors, SIDDHARTA and KLOE-2. Considering a high efficiency of the scheme for increasing collision luminosity and its relative simplicity for implementation several new collider projects have been proposed and are under development at present. These are the SuperKEKB B-factory ready to start commissioning in 2016 in Japan, the SuperC-Tau factory proposed in Novosibirsk and entered in the short list of Russian mega-science projects, the new 100-km electron-positron Future Circular Collider (FCC-ee) under design study at CERN and some others. In this paper we describe the CW collision scheme, discuss its advantages and report principal results achieved at the electron-positron Phi-factory DAFNE.

  15. The eRHIC Ring-Ring Collider Design

    CERN Document Server

    Wang, Fuhua; Beebe-Wang, Joanne; Deshpande, Abhay A; Farkhondeh, Manouchehr; Franklin, Wilbur; Graves, William; Litvinenko, Vladimir N; MacKay, William W; Milner, Richard; Montag, Christoph; Ozaki, Satoshi; Parker, Brett; Peggs, Steve; Ptitsyn, Vadim; Roser, Thomas; Tepikian, Steven; Trbojevic, Dejan; Tschalär, C; Wang, Dong; Zolfaghari, Abbasali; Zwart, Townsend; van der Laan, Jan

    2005-01-01

    The eRHIC ring-ring collider is the main design option of the future lepton-ion collider at Brookhaven National Laboratory. We report the revisions of the ring-ring collider design features to the baseline design presented in the eRHIC Zeroth Design Report (ZDR). These revisions have been made during the past year. They include changes of the interaction region which are required from the modifications in the design of the main detector. They also include changes in the lepton storage ring for high current operations as a result of better understandings of beam-beam interaction effects. The updated collider luminosity and beam parameters also take into account a more accurate picture of current and future operational aspects of RHIC.

  16. Status of the MEIC ion collider ring design

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Derbenev, Yaroslav [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Harwood, Leigh [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Hutton, Andrew [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Pilat, Fulvia [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Cai, Yunhai [SLAC National Accelerator Lab., Menlo Park, CA (United States); Nosochkov, Y. M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Sullivan, Michael [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wang, M.-H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wienands, Uli [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gerity, James [Texas A & M Univ., College Station, TX (United States); Mann, Thomas [Texas A & M Univ., College Station, TX (United States); McIntyre, Peter [Texas A & M Univ., College Station, TX (United States); Pogue, Nathaniel [Texas A & M Univ., College Station, TX (United States); Sattarov, Akhdiyor [Texas A & M Univ., College Station, TX (United States)

    2015-09-01

    We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

  17. Status of the MEIC ion collider ring design

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-07-14

    We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

  18. Perturbative QCD tests from the LEP, HERA, and TEVATRON colliders

    Energy Technology Data Exchange (ETDEWEB)

    Kuhlmann, S. [Argonne National Lab., IL (United States)

    1994-09-01

    A review of QCD tests from LEP, HERA and the TEVATRON colliders is presented. This includes jet production, quark/gluon jet separation, quark/gluon propagator spin, {alpha}{sub s} updates, photon production, and rapidity gap experiments.

  19. High Energy Accelerator and Colliding Beam User Group

    Energy Technology Data Exchange (ETDEWEB)

    Snow, G.A.; Skuja, A.

    1992-05-01

    This report discusses research in the following areas: the study of e{sup +}e{sup {minus}} interactions; Hadron collider physics at Fermilab; fixed target physics and particle physics of general interest; and, the solenoidal detector collaboration at SSCL.

  20. NICADD scientists develop detector technology for International Linear Collider

    CERN Multimedia

    2006-01-01

    "Scientist at the Northern Illinois Center for Accelerator and Detector Development (NICADD) are celebrating the successful run of a prototype subdetector for the proposed International Linear Collider (ILC)." (1 page)

  1. Laser-plasma-based linear collider using hollow plasma channels

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, C.B., E-mail: CBSchroeder@lbl.gov; Benedetti, C.; Esarey, E.; Leemans, W.P.

    2016-09-01

    A linear electron–positron collider based on laser-plasma accelerators using hollow plasma channels is considered. Laser propagation and energy depletion in the hollow channel is discussed, as well as the overall efficiency of the laser-plasma accelerator. Example parameters are presented for a 1-TeV and 3-TeV center-of-mass collider based on laser-plasma accelerators.

  2. Heavy Meson Production at a Low-Energy Photon Collider

    Energy Technology Data Exchange (ETDEWEB)

    Asztalos, S

    2004-04-15

    A low-energy {gamma}{gamma} collider has been discussed in the context of a testbed for a {gamma}{gamma} interaction region at the Next Linear Collider(NLC). We consider the production of heavy mesons at such a testbed using Compton-backscattered photons and demonstrate that their production rivals or exceeds those by BELLE, BABAR or LEP where they are produced indirectly via virtual {gamma}{gamma} luminosities.

  3. Extended gauge models at e+e- colliders

    CERN Document Server

    Djouadi, Abdelhak

    1995-01-01

    We summarize the potential of high--energy \\ee linear colliders for discovering, and in case of discovery, for studying the signals of extended gauge models. We will mainly focus on the virtual signals of new neutral gauge bosons and on the production of new heavy leptons. [Invited talk given at the Workshop on Physics and Experiments with Linear Colliders, Morioka-Appi, Japan, September 8-12 1995.

  4. Optical data transmission at the superconducting super collider

    Energy Technology Data Exchange (ETDEWEB)

    Leskovar, B. [Lawrence Berkeley Lab., CA (United States)

    1989-04-01

    Digital and analog data transmissions via fiber optics for the Superconducting Super Collider have been investigated. The state of the art of optical transmitters, low loss fiber waveguides, receivers and associated electronics components are reviewed and summarized. Emphasis is placed on the effects of the radiation environment on the performance of an optical data transmission system components. Also, the performance of candidate components of the wide band digital and analog transmission systems intended for deployment in the Superconducting Super Collider Detector is discussed.

  5. The Higgs boson and the International Linear Collider

    Directory of Open Access Journals (Sweden)

    Francesca eBorzumati

    2014-06-01

    Full Text Available The Higgs boson will be subject of intense experimental searches in future high-energy experiments. In addition to the e□ort made at the Large Hadron Collider, where it was discovered, it will be the major subject of study at the International Linear Collider. We review here the reasons for that and some of the issues to be tackled at this future accelerator.

  6. Operational readiness verification, phase 1: A study on safety during outage and restart of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hollnagel, E. [Linkoeping Univ. (Sweden). Dept. of Computer and Information Science; Gauthereau, V. [Linkoeping Univ. (Sweden). Dept. of Industrial Engineering

    2001-06-01

    This report contains the findings from the first phase of a study on safety during outage and restart of nuclear power plants. Operational Readiness Verification (ORV) - in Swedish called Driftklarhetsverifiering (DKV) - refers to the test and verification activities that are necessary to ensure that plant systems are able to provide their required functions when needed - more concretely that all plant systems are in their correct functional state when the plant is restarted after an outage period. The concrete background for this work is that nine ORV related incidents were reported in Sweden between July 1995 and October 1998. The work reported here comprised a literature survey of research relevant for ORV issues, and an assessment of the present situation at Swedish NPPs with respect to ORV. The literature survey was primarily aimed at research related to NPPs, but also looked at domains where similar problems have occurred, such as maintenance in commercial aviation. The survey looked specifically for organisational and MTO aspects relevant to the present situation in Swedish NPPs. One finding was that ORV should be seen as an integral part of maintenance, rather than as a separate activity. Another, that there is a characteristic distribution of error modes for maintenance and ORV, with many sequence errors and omissions, rather than a set of unique error modes. An international study further showed that there are important differences in how procedures are used, and in the balance between decentralisation and centralisation. Several studies also suggested that ORV could usefully be described as a barrier system in relation to the flow of work, for instance using the following five stages: (1) preventive actions during maintenance/outage, (2) post-test after completion of work, (3) pre-test before start-up, (4) the start-up sequence itself, and (5) preventive actions during power operation - possibly including automatic safety systems. In the field survey

  7. Will there be energy frontier colliders after LHC?

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir [Fermilab

    2016-09-15

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). The future of the world-wide HEP community critically depends on the feasibility of possible post-LHC colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity and feasibility of cost. Here we overview all current options for post-LHC colliders from such perspective (ILC, CLIC, Muon Collider, plasma colliders, CEPC, FCC, HE-LHC) and discuss major challenges and accelerator R&D required to demonstrate feasibility of an energy frontier accelerator facility following the LHC. We conclude by taking a look into ultimate energy reach accelerators based on plasmas and crystals, and discussion on the perspectives for the far future of the accelerator-based particle physics.

  8. Crystal Ball: On the Future High Energy Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir [Fermilab

    2015-09-20

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of next generation collider facilities have been proposed and are currently under consideration for the medium- and far-future of the accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance reach and cost range. We briefly review such post-LHC options as linear e+e- colliders in Japan (ILC) or at CERN (CLIC), muon collider, and circular lepton or hadron colliders in China (CepC/SppC) and Europe (FCC). We conclude with a look into ultimate energy reach accelerators based on plasmas and crystals, and some perspectives for the far future of accelerator-based particle physics.

  9. Crystal Ball: On the Future High Energy Colliders

    CERN Document Server

    Shiltsev, Vladimir

    2015-01-01

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of next generation collider facilities have been proposed and are currently under consideration for the medium- and far-future of the accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance reach and cost range. We briefly review such post-LHC options as linear e+e- colliders in Japan (ILC) or at CERN (CLIC), muon collider, and circular lepton or hadron colliders in China (CepC/SppC) and Europe (FCC). We conclude with a look into ultimate energy reach accelerators based on plasmas and crystals, and some perspectives for the far future of ...

  10. Status of muon collider research and development and future plans

    Directory of Open Access Journals (Sweden)

    1999-08-01

    Full Text Available The status of the research on muon colliders is discussed and plans are outlined for future theoretical and experimental studies. Besides work on the parameters of a 3–4 and 0.5 TeV center-of-mass (COM energy collider, many studies are now concentrating on a machine near 0.1 TeV (COM that could be a factory for the s-channel production of Higgs particles. We discuss the research on the various components in such muon colliders, starting from the proton accelerator needed to generate pions from a heavy-Z target and proceeding through the phase rotation and decay (π→μν_{μ} channel, muon cooling, acceleration, storage in a collider ring, and the collider detector. We also present theoretical and experimental R&D plans for the next several years that should lead to a better understanding of the design and feasibility issues for all of the components. This report is an update of the progress on the research and development since the feasibility study of muon colliders presented at the Snowmass '96 Workshop [R. B. Palmer, A. Sessler, and A. Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics (Stanford Linear Accelerator Center, Menlo Park, CA, 1997].

  11. Analysis of the Hydrologic Response Associated with Shutdown and Restart of the 200-ZP-1 Pump-and-Treat System

    Energy Technology Data Exchange (ETDEWEB)

    Spane, Frank A.; Thorne, Paul D.

    2000-09-08

    A number of programs have been implemented on the Hanford Site that utilize the pumping and treatment of contaminated groundwater as part of their remediation strategy. Often the treated water is reinjected into the aquifer at injection well sites. The implementation of remedial pump and treat systems, however, results in hydraulic pressure responses, both areally and vertically (i.e., with depth) within the pumped aquifer. The area within the aquifer affected by the pump and treat system (i.e., radius of influence) is commonly estimated based on detecting associated water-level responses within surrounding monitor wells. Natural external stresses, such as barometric pressure fluctuations, however, can have a discernible impact on well water-level measurements. These temporal barometric effects may significantly mask water-level responses within more distant wells that are only slightly affected (< 0.10 m) by the test system. External stress effects, therefore, can lead to erroneous indications of the radius of influence of the imposed pump and treat system remediation activities and can greatly diminish the ability to analyze the associated well responses for hydraulic property characterization. When these extraneous influences are significant, adjustments or removal of the barometric effects from the test-response record may be required for quantitative hydrologic assessment. This report examines possible hydrologic effects of pump and treat remediation actions and provides a detailed analysis of water-level measurements for selected 200-ZP-1 pump and treat system monitor wells during the recent Y2K shutdown (December 1999) and restart activity (January 2000). The general findings presented in this report have universal application for unconfined and confined aquifer systems.

  12. Governance of the International Linear Collider Project

    Energy Technology Data Exchange (ETDEWEB)

    Foster, B.; /Oxford U.; Barish, B.; /Caltech; Delahaye, J.P.; /CERN; Dosselli, U.; /INFN, Padua; Elsen, E.; /DESY; Harrison, M.; /Brookhaven; Mnich, J.; /DESY; Paterson, J.M.; /SLAC; Richard, F.; /Orsay, LAL; Stapnes, S.; /CERN; Suzuki, A.; /KEK, Tsukuba; Wormser, G.; /Orsay, LAL; Yamada, S.; /KEK, Tsukuba

    2012-05-31

    Governance models for the International Linear Collider Project are examined in the light of experience from similar international projects around the world. Recommendations for one path which could be followed to realize the ILC successfully are outlined. The International Linear Collider (ILC) is a unique endeavour in particle physics; fully international from the outset, it has no 'host laboratory' to provide infrastructure and support. The realization of this project therefore presents unique challenges, in scientific, technical and political arenas. This document outlines the main questions that need to be answered if the ILC is to become a reality. It describes the methodology used to harness the wisdom displayed and lessons learned from current and previous large international projects. From this basis, it suggests both general principles and outlines a specific model to realize the ILC. It recognizes that there is no unique model for such a laboratory and that there are often several solutions to a particular problem. Nevertheless it proposes concrete solutions that the authors believe are currently the best choices in order to stimulate discussion and catalyze proposals as to how to bring the ILC project to fruition. The ILC Laboratory would be set up by international treaty and be governed by a strong Council to whom a Director General and an associated Directorate would report. Council would empower the Director General to give strong management to the project. It would take its decisions in a timely manner, giving appropriate weight to the financial contributions of the member states. The ILC Laboratory would be set up for a fixed term, capable of extension by agreement of all the partners. The construction of the machine would be based on a Work Breakdown Structure and value engineering and would have a common cash fund sufficiently large to allow the management flexibility to optimize the project's construction. Appropriate contingency

  13. Design of beam optics for the Future Circular Collider e+e- -collider rings

    CERN Document Server

    Oide, K.; Aumon, S.; Benedikt, M.; Blondel, A.; Bogomyagkov, A.; Boscolo, M.; Burkhardt, H.; Cai, Y.; Doblhammer, A.; Haerer, B.; Holzer, B.; Jowett, J.M.; Koop, I.; Koratzinos, M.; Levichev, E.; Medina, L.; Ohmi, K.; Papaphilippou, Y.; Piminov, P.; Shatilov, D.; Sinyatkin, S.; Sullivan, M.; Wenninger, J.; Wienands, U.; Zhou, D.; Zimmermann, F.; CERN. Geneva. ATS Department

    2016-01-01

    A beam optics scheme has been designed for the Future Circular Collider-e+e- (FCC-ee). The main characteristics of the design are: beam energy 45 to 175 GeV, 100 km circumference with two interaction points (IPs) per ring, horizontal crossing angle of 30 mrad at the IP and the crab-waist scheme [1] with local chromaticity correction. The crab-waist scheme is implemented within the local chromaticity correction system without additional sextupoles, by reducing the strength of one of the two sextupoles for vertical chromatic correction at each side of the IP. So-called "tapering" of the magnets is applied, which scales all fields of the magnets according to the local beam energy to compensate for the effect of synchrotron radiation (SR) loss along the ring. An asymmetric layout near the interaction region reduces the critical energy of SR photons on the incoming side of the IP to values below 100 keV, while matching the geometry to the beam line of the FCC proton collider (FCC-hh) [2] as closely as possible. Su...

  14. American Dream Delayed

    DEFF Research Database (Denmark)

    Khorunzhina, Natalia; Miller, Robert A.

    This paper investigates the delay in homeownership and a subsequent reduction in homeownership rate observed over the past decades. We focus on the delay in giving birth to children and increased labor market participation as contributing factors to homeownership dynamics for prime-age female hou...

  15. DCal: A custom integrated circuit for calorimetry at the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, James R.; Mekkaoui, Abderrazek; Yarema, Ray; /Fermilab; Drake, Gary; Repond, Jose; /Argonne

    2005-10-01

    A research and development collaboration has been started with the goal of producing a prototype hadron calorimeter section for the purpose of proving the Particle Flow Algorithm concept for the International Linear Collider. Given the unique requirements of a Particle Flow Algorithm calorimeter, custom readout electronics must be developed to service these detectors. This paper introduces the DCal or Digital Calorimetry Chip, a custom integrated circuit developed in a 0.25um CMOS process specifically for this International Linear Collider project. The DCal is capable of handling 64 channels, producing a 1-bit Digital-to-Analog conversion of the input (i.e. hit/no hit). It maintains a 24-bit timestamp and is capable of operating either in an externally triggered mode or in a self-triggered mode. Moreover, it is capable of operating either with or without a pipeline delay. Finally, in order to permit the testing of different calorimeter technologies, its analog front end is capable of servicing Particle Flow Algorithm calorimeters made from either Resistive Plate Chambers or Gaseous Electron Multipliers.

  16. High-Power Multimode X-Band RF Pulse Compression System for Future Linear Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Tantawi, S.G.; Nantista, C.D.; Dolgashev, V.A.; Pearson, C.; Nelson, J.; Jobe, K.; Chan, J.; Fant, K.; Frisch, J.; /SLAC; Atkinson, D.; /LLNL, Livermore

    2005-08-10

    We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  17. Workshop on physics at the first muon collider and front-end of a muon collider: A brief summary

    Energy Technology Data Exchange (ETDEWEB)

    Geer, S.

    1998-02-01

    In November 1997 a workshop was held at Fermilab to explore the physics potential of the first muon collider, and the physics potential of the accelerator complex at the `front-end` of the collider. An extensive physics program emerged from the workshop. This paper attempts to summarize this physics program and to identify the main conclusions from the workshop. 14 refs., 1 fig., 5 tabs.

  18. Collide and Conquer: Constraints on Simplified Dark Matter Models using Mono-X Collider Searches

    CERN Document Server

    Brennan, A J; Gramling, J; Jacques, T D

    2016-01-01

    The use of simplified models as a tool for interpreting dark matter collider searches has become increasingly prevalent, and while early Run II results are beginning to appear, we look to see what further information can be extracted from the Run I dataset. We consider three `standard' simplified models that couple quarks to fermionic singlet dark matter: an $s$-channel vector mediator with vector or axial-vector couplings, and a $t$-channel scalar mediator. Upper limits on the couplings are calculated and compared across three alternate channels, namely mono-jet, mono-$Z$ (leptonic) and mono-$W/Z$ (hadronic). The strongest limits are observed in the mono-jet channel, however the computational simplicity and absence of significant $t$-channel model width effects in the mono-boson channels make these a straightforward and competitive alternative. We also include a comparison with relic density and direct detection constraints.

  19. commensurate point delays

    Directory of Open Access Journals (Sweden)

    M. de la Sen

    2005-01-01

    nominal controller is maintained. In the current approach, the finite spectrum assignment is only considered as a particular case of the designer's choice of a (delay-dependent arbitrary spectrum assignment objective.

  20. Heat exchanger restart evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, J.M.; Hirst, C.W.; Lentz, T.F.

    1992-02-28

    On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat exchanger 4A (HX 4A). The heat exchanger was isolated and the plant shutdown. Heat exchanger 4kA was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat exchanger 4A for metallurgical examination. Additional analysis and review of heat exchanger leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summarized herein.

  1. LHC restart 2016

    CERN Multimedia

    CERN Audiovisual production

    2016-01-01

    Footage of first injection of proton beam in the LHC machine, that took place on Friday March 25, 2016, at the injection energy of 450 GeV. Interview to Mike Lamont, head of LHC operations and of Fabiola Gianotti, CERN Director General. General footage of the Cern Control Centre on first beam 2016 day, the LHC machine operators and Engineers in Charge at work, relevant screens summarizing the machine parametres. Views of the LHC tunnel and the 4 main experimental caverns with views of the ATLAS, CMS, ALICE and LHCb detectors. 3 D animations of the CERN accelerator complex, from the Linac, to the PS, SPS and the LHC. VOICE OVER : Alex Brown

  2. A 233 km Tunnel for Lepton and Hadron Colliders

    CERN Document Server

    Summers, D J; Datta, A; Duraisamy, M; Luo, T; Lyons, G T

    2012-01-01

    A decade ago, a cost analysis was conducted to bore a 233 km circumference Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we outline implementations of $e^+e^-$, $p \\bar{p}$, and $\\mu^+ \\mu^-$ collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV $e^+e^-$ colliders employ Crab Waist Crossings, ultra low emittance damped bunches, short vertical IP focal lengths, superconducting RF, and low coercivity, grain oriented silicon steel/concrete dipoles. Some details are also provided for a high luminosity 240 GeV $e^+ e^-$ collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV $p \\bar{p}$ collider uses the high intensity Fermilab $\\bar{p}$ source, exploits high cross sections for $p \\bar{p}$ production of high mass states, and uses 2 Tesla ultra low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds, uses 250 GV of superconduct...

  3. A 233 km tunnel for lepton and hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Summers, D. J.; Cremaldi, L. M.; Datta, A.; Duraisamy, M.; Luo, T.; Lyons, G. T. [Dept. of Physics and Astronomy, University of Mississippi-Oxford, University, MS 38677 (United States)

    2012-12-21

    A decade ago, a cost analysis was conducted to bore a 233 km circumference Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we outline implementations of e{sup +}e{sup -}, pp-bar , and {mu}{sup +}{mu}{sup -} collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV e{sup +}e{sup -} colliders employ Crab Waist Crossings, ultra low emittance damped bunches, short vertical IP focal lengths, superconducting RF, and low coercivity, grain oriented silicon steel/concrete dipoles. Some details are also provided for a high luminosity 240 GeV e{sup +}e{sup -} collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV pp-bar collider uses the high intensity Fermilab p-bar source, exploits high cross sections for pp-bar production of high mass states, and uses 2 Tesla ultra low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds, uses 250 GV of superconducting RF to accelerate muons from 1.75 to 17.5 TeV in 63 orbits with 71% survival, and mitigates neutrino radiation with phase shifting, roller coaster motion in a FODO lattice.

  4. Transverse beams stability studies at the Large Hadron Collider

    CERN Document Server

    Buffat, Xavier; Pieloni, Tatiana

    2015-01-30

    A charged particle beam travelling at the speed of light produces large electromagnetic wake fields which, through interactions with its surroundings, act back on the particles in the beam. This coupled system may become unstable, resulting in a deterioration of the beam quality. Such effects play a major role in most existing storage rings, as they limit the maximum performance achievable. In a collider, the presence of a second beam significantly changes the dynamics, as the electromagnetic interactions of the two beams on each other are usually very strong and may, also, limit the collider performances. This thesis treats the coherent stability of the two beams in a circular collider, including the effects of the electromagnetic wake fields and of the beam-beam interactions, with particular emphasis on CERN's Large Hadron Collider. As opposed to other colliders, this machine features a large number of bunches per beam each experiencing multiple long-range and head-on beam-beam interactions. Existing models...

  5. Alpha thalassemia/mental retardation syndrome X-linked gene product ATRX is required for proper replication restart and cellular resistance to replication stress.

    Science.gov (United States)

    Leung, Justin Wai-Chung; Ghosal, Gargi; Wang, Wenqi; Shen, Xi; Wang, Jiadong; Li, Lei; Chen, Junjie

    2013-03-01

    Alpha thalassemia/mental retardation syndrome X-linked (ATRX) is a member of the SWI/SNF protein family of DNA-dependent ATPases. It functions as a chromatin remodeler and is classified as an SNF2-like helicase. Here, we showed somatic knock-out of ATRX displayed perturbed S-phase progression as well as hypersensitivity to replication stress. ATRX is recruited to sites of DNA damage, required for efficient checkpoint activation and faithful replication restart. In addition, we identified ATRX as a binding partner of MRE11-RAD50-NBS1 (MRN) complex. Together, these results suggest a non-canonical function of ATRX in guarding genomic stability.

  6. Time Delay Cosmography

    OpenAIRE

    Treu, Tommaso; Marshall, Philip J.

    2016-01-01

    Gravitational time delays, observed in strong lens systems where the variable background source is multiply-imaged by a massive galaxy in the foreground, provide direct measurements of cosmological distance that are very complementary to other cosmographic probes. The success of the technique depends on the availability and size of a suitable sample of lensed quasars or supernovae, precise measurements of the time delays, accurate modeling of the gravitational potential of the main deflector,...

  7. Heavy-ion physics studies for the Future Circular Collider

    Science.gov (United States)

    Armesto, N.; Dainese, A.; d'Enterria, D.; Masciocchi, S.; Roland, C.; Salgado, C. A.; van Leeuwen, M.; Wiedemann, U. A.

    2014-11-01

    The Future Circular Collider (FCC) design study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron-hadron collision mode including proton and nucleus beams, more than seven times larger than the nominal LHC energies. An electron-positron collider in the same tunnel is also considered as an intermediate step, which in the long term would allow for electron-hadron collisions. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of quark-gluon plasma, gluon saturation, photon-induced collisions, as well as connections with the physics of ultra-high-energy cosmic rays.

  8. Heavy-ion physics studies for the Future Circular Collider

    Energy Technology Data Exchange (ETDEWEB)

    Armesto, N. [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Dainese, A., E-mail: andrea.dainese@pd.infn.it [INFN — Sezione di Padova, 35131 Padova (Italy); D' Enterria, D. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland); Masciocchi, S. [EMMI and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Roland, C. [Massachusetts Institute of Technology, Cambridge, MA 02139-4307 (United States); Salgado, C.A. [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Leeuwen, M. van [Nikhef, National Institute for Subatomic Physics and Institute for Subatomic Physics of Utrecht University, Utrecht (Netherlands); Wiedemann, U.A. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland)

    2014-11-15

    The Future Circular Collider (FCC) design study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron–hadron collision mode including proton and nucleus beams, more than seven times larger than the nominal LHC energies. An electron–positron collider in the same tunnel is also considered as an intermediate step, which in the long term would allow for electron–hadron collisions. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of quark–gluon plasma, gluon saturation, photon-induced collisions, as well as connections with the physics of ultra-high-energy cosmic rays.

  9. Lineshape of the Higgs boson in future lepton colliders

    Science.gov (United States)

    Jadach, S.; Kycia, R. A.

    2016-04-01

    The effect of the photon emission (initial-state radiation) in the cross section of the process of direct production of the Higgs boson in future high luminosity electron and muon colliders is calculated. It was found that the cross section at the top of the Higgs boson resonance peak is reduced by a factor 0.348 for the electron collider and 0.548 for the muon collider. A centre-of-mass energy spread of the centre-of-mass energy of 4.2 MeV (equal to the Higgs width) would reduce peak cross section further, by a factor 0.170 and 0.256 (QED and energy spread) for electron and muon beams respectively. Possible uncertainties in the resummed QED calculations are discussed. Numerical results for the lineshape cross section including QED and many values of the centre-of-mass energy spread are provided.

  10. Disambiguating Seesaw Models using Invariant Mass Variables at Hadron Colliders

    CERN Document Server

    Dev, P S Bhupal; Mohapatra, Rabindra N

    2015-01-01

    We propose ways to distinguish between different mechanisms behind the collider signals of TeV-scale seesaw models for neutrino masses using kinematic endpoints of invariant mass variables. We particularly focus on two classes of such models widely discussed in literature: (i) Standard Model extended by the addition of singlet neutrinos and (ii) Left-Right Symmetric Models. Relevant scenarios involving the same "smoking-gun" collider signature of dilepton plus dijet with no missing transverse energy differ from one another by their event topology, resulting in distinctive relationships among the kinematic endpoints to be used for discerning them at hadron colliders. These kinematic endpoints are readily translated to the mass parameters of the on-shell particles through simple analytic expressions which can be used for measuring the masses of the new particles. A Monte Carlo simulation with detector effects is conducted to test the viability of the proposed strategy in a realistic environment. Finally, we dis...

  11. Update on the MEIC electron collider ring design

    Energy Technology Data Exchange (ETDEWEB)

    Lin, F. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Ya. S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Harwood, L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hutton, A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, V. S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Pilat, F. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Y. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Cai, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Nosochkov, Y. M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Sullivan, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wang, M-H [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wienands, U. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-07-14

    The electron collider ring of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab is designed to accumulate and store a high-current polarized electron beam for collisions with an ion beam. We consider a design of the electron collider ring based on reusing PEPII components, such as magnets, power supplies, vacuum system, etc. This has the potential to significantly reduce the cost and engineering effort needed to bring the project to fruition. This paper reports on an electron ring optics design considering the balance of PEP-II hardware parameters (such as dipole sagitta, magnet field strengths and acceptable synchrotron radiation power) and electron beam quality in terms of equilibrium emittances.

  12. Power Saving Optimization for Linear Collider Interaction Region Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Seryi, Andrei; /SLAC

    2009-10-30

    Optimization of Interaction Region parameters of a TeV energy scale linear collider has to take into account constraints defined by phenomena such as beam-beam focusing forces, beamstrahlung radiation, and hour-glass effect. With those constraints, achieving a desired luminosity of about 2E34 would require use of e{sup +}e{sup -} beams with about 10 MW average power. Application of the 'travelling focus' regime may allow the required beam power to be reduced by at least a factor of two, helping reduce the cost of the collider, while keeping the beamstrahlung energy loss reasonably low. The technique is illustrated for the 500 GeV CM parameters of the International Linear Collider. This technique may also in principle allow recycling the e{sup +}e{sup -} beams and/or recuperation of their energy.

  13. Dark Matter Searches at the Large Hadron Collider

    CERN Document Server

    Hoh, Siew Yan; Abdullah, Wan Ahmad Tajuddin Bin Wan

    2015-01-01

    Dark Matter is a hypothetical particle proposed to explain the missing matter expected from the cosmological observation. The motivation of Dark Matter is overwhelming however as it is mainly deduced from its gravitational interaction, for it does little to pinpoint what Dark Matter really is. In WIMPs Miracle, weakly interactive massive particle being the Dark Matter candidate is correctly producing the current thermal relic density at weak scale, implying the possibility of producing and detecting it in Large Hadron Collider. Assuming WIMPs being the maverick particle within collider, it is expected to be pair produced in association with a Standard Model particle. The presence of the WIMPs pair is inferred from the Missing Transverse Energy (MET) which is the vector sum of the imbalance in the transverse momentum plane recoils a Standard Model Particle. The collider is able to produce light mass Dark Matter which the traditional detection fail to detect due to the small momentum transfer involved in the in...

  14. Update on the MEIC electron collider ring design

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Fangei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Harwood, Leigh [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hutton, Andrew [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Pilat, Fulvia [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Cai, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Nosochkov, Y. M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Sullivan, Michael [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wang, M.-H [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wienands, Uli [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-09-01

    The electron collider ring of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab is designed to accumulate and store a high-current polarized electron beam for collisions with an ion beam. We consider a design of the electron collider ring based on reusing PEP-II components, such as magnets, power supplies, vacuum system, etc. This has the potential to significantly reduce the cost and engineering effort needed to bring the project to fruition. This paper reports on an electron ring optics design considering the balance of PEP-II hardware parameters (such as dipole sagitta, magnet field strengths and acceptable synchrotron radiation power) and electron beam quality in terms of equilibrium emittances.

  15. Status of Muon Collider Research and Development and Future Plans

    CERN Document Server

    Ankenbrandt, C M; Autin, Bruno; Balbekov, Valeri I; Barger, Vernon D; Benary, Odette; Berg, J Scott; Berger, Michael S; Black, Edgar L; Blondel, Alain; Bogacz, S Alex; Bolton, T; Caspi, Sholomo; Celata, Chrisine; Chou, Weiren; Cline, David B; Corlett, John; Cremaldi, Lucien; Diehl, H Thomas; Drozhdin, Alexandr; Fernow, Richard C; Finley, David A; Fukui, Yasuo; Furman, Miguel A; Gabriel, Tony; Gallardo, Juan C; Garren, Alper A; Geer, Stephen H; Ginzburg, Ilya F; Green, Michael A; Guler, Hulya; Gunion, John F; Gupta, Ramesh; Han, Tao; Hanson, Gail G; Hassanein, Ahmed; Holtkamp, Norbert; Johnson, Colin; Johnstone, Carol; Kahn, Stephen A; Kaplan, Daniel M; Kim, Eun San; King, Bruce J; Kirk, Harold G; Kuno, Yoshitaka; Paul Lebrun; Lee, Kevin; Lee, Peter; Li, Derun; Lissauer, David; Littenberg, Laurence S; Lu, Changguo; Luccio, Alfredo; Lykken, Joseph D; McDonald, Kirk T; McInturff, Alfred D; Miller, John R; Mills, Frederick E; Mokhov, Nikolai V; Moretti, Alfred; Mori, Yoshiharu; Neuffer, David V; Ng, King-Yuen; Noble, Robert J; Norem, James H; Onel, Yasar; Palmer, Robert B; Parsa, Zohreh; Pischalnikov, Yuriy; Popovic, Milorad; Prebys, EricJ; Qian, Zubao; Raja, Rajendran; Reed, Claude B; Rehák, Pavel; Roser, Thomas; Rossmanith, Robert; Scanlan, Ronald M; Sessler, Andrew M; Schadwick, Brad; Shu, Quan-Sheng; Silvestrov, Gregory I; Skrinsky, Alexandr N; Smith, Dale; Spentzouris, Panagiotis; Stefanski, Ray; Striganov, Sergei; Stumer, Iuliu; Summers, Don; Tcherniatine, Valeri; Teng, Lee C; Tollestrup, Alvin V; Torun, Yagmur; Trbojevic, Dejan; Turner, William C; Vahsen, Sven E; Van Ginneken, Andy; Vsevolozhskaya, Tatiana A; Wan, Weishi; Wang, Haipeng; Weggel, Robert; Willen, Erich H; Wilson, Edmund J N; Winn, David R; Wurtele, Jonathan S; Ankenbrandt, Charles M.

    1999-01-01

    The status of the research on muon colliders is discussed and plans are outlined for future theoretical and experimental studies. Besides continued work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy collider, many studies are now concentrating on a machine near 0.1 TeV (CoM) that could be a factory for the s-channel production of Higgs particles. We discuss the research on the various components in such muon colliders, starting from the proton accelerator needed to generate pions from a heavy-Z target and proceeding through the phase rotation and decay ($\\pi \\to \\mu \

  16. Heavy-ion physics studies for the Future Circular Collider

    CERN Document Server

    Armesto, Nestor; d'Enterria, David; Masciocchi, Silvia; Roland, Christof; Salgado, Carlos; van Leeuwen, Marco; Wiedemann, Urs

    2014-01-01

    The Future Circular Collider (FCC) design study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron-hadron collision mode including proton and nucleus beams, more than seven-times larger than the nominal LHC energies. An electron-positron collider in the same tunnel is also considered as an intermediate step, which would provide the electron-hadron option in the long term. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of Quark-Gluon Plasma, gluon saturation, photon-induced collisions, as well as connections with ultra-high-energy cosmic rays.

  17. A Novel Collimation Method for Large Hadron Colliders

    CERN Document Server

    Zou, Ye; Tang, Jingyu

    2016-01-01

    This paper proposes a novel collimation method for large hadron colliders by arranging betatron and momentum collimation systems in the same insertion to improve the overall cleaning efficiency. The method has the potential of avoiding beam losses at the downstream dispersion suppression section following the conventional betatron collimation section, which is caused by those particles with single diffractive scattering at the collimators. Evident beam loss in arc sections should be avoided to protect the superconducting magnets from quenching, especially when the stored beam energy is up to hundreds of MJ level or even higher in modern proton-proton collider. Our studies show that it is beneficial to arrange the momentum collimation system just after the betatron collimation system so that it can clean the particles with lower momentum due to the single diffractive scattering in the betatron collimators. This method is being applied to the future proton-proton collider SPPC. Preliminary multi-particle simula...

  18. Symmetric Achromatic Low-Beta Collider Interaction Region Design Concept

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Vasiliy S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Johnson, Rolland P. [Muons, Inc., Batavia, IL (United States)

    2013-01-01

    We present a new symmetry-based concept for an achromatic low-beta collider interaction region design. A specially-designed symmetric Chromaticity Compensation Block (CCB) induces an angle spread in the passing beam such that it cancels the chromatic kick of the final focusing quadrupoles. Two such CCB?s placed symmetrically around an interaction point allow simultaneous compensation of the 1st-order chromaticities and chromatic beam smear at the IP without inducing significant 2nd-order aberrations. We first develop an analytic description of this approach and explicitly formulate 2nd-order aberration compensation conditions at the interaction point. The concept is next applied to develop an interaction region design for the ion collider ring of an electron-ion collider. We numerically evaluate performance of the design in terms of momentum acceptance and dynamic aperture. The advantages of the new concept are illustrated by comparing it to the conventional distributed-sextupole chromaticity compensation scheme.

  19. Symmetric achromatic low-beta collider interaction region design concept

    CERN Document Server

    Morozov, V S; Lin, F; Johnson, R P

    2012-01-01

    We present a new symmetry-based concept for an achromatic low-beta collider interaction region design. A specially-designed symmetric Chromaticity Compensation Block (CCB) induces an angle spread in the passing beam such that it cancels the chromatic kick of the final focusing quadrupoles. Two such CCBs placed symmetrically around an interaction point allow simultaneous compensation of the 1st-order chromaticities and chromatic beam smear at the IP without inducing significant 2nd-order aberrations to the particle trajectory. We first develop an analytic description of this approach and explicitly formulate 2nd-order aberration compensation conditions at the interaction point. The concept is next applied to develop an interaction region design for the ion collider ring of an electron-ion collider. We numerically evaluate performance of the design in terms of momentum acceptance and dynamic aperture. The advantages of the new concept are illustrated by comparing it to the conventional distributed-sextupole chr...

  20. Academic Training Lecture: Higgs Boson Searches at Hadron Colliders

    CERN Multimedia

    HR Department

    2010-01-01

    Regular Programme 21, 22, 23 & 24 June 2010 from 11:00 to 12:00 - Main Auditorium, Bldg. 500-1-001 Higgs Boson Searches at Hadron Colliders by Dr. Karl Jakobs (University of Freiburg) In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and ...

  1. Massive Stars in Colliding Wind Systems: the GLAST Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Reimer, Anita; Reimer, Olaf; /Stanford U., HEPL /KIPAC, Menlo Park

    2011-11-29

    Colliding winds of massive stars in binary systems are considered as candidate sites of high-energy non-thermal photon emission. They are already among the suggested counterparts for a few individual unidentified EGRET sources, but may constitute a detectable source population for the GLAST observatory. The present work investigates such population study of massive colliding wind systems at high-energy gamma-rays. Based on the recent detailed model (Reimer et al. 2006) for non-thermal photon production in prime candidate systems, we unveil the expected characteristics of this source class in the observables accessible at LAT energies. Combining the broadband emission model with the presently cataloged distribution of such systems and their individual parameters allows us to conclude on the expected maximum number of LAT-detections among massive stars in colliding wind binary systems.

  2. Top physics at high-energy lepton colliders

    CERN Document Server

    Vos, M; Beneke, M; Bilokin, S; Costa, M; De Curtis, S; Fujii, K; Fuster, J; Garcia, I Garcia; Gomis, P; Hoang, A; Irles, A; Kiyo, Y; Kurata, M; Linssen, L; List, J; Nebot, M; Rosello, M Perello; Poeschl, R; Quach, N; Reuter, J; Richard, F; Rodrigo, G; Roloff, Ph; Ros, E; Simon, F; Tian, J; Zarnecki, A F

    2016-01-01

    A summary is presented of the workshop "top physics at linear colliders" that was held at IFIC Valencia from the 30th of June to the 3rd July 2015. We present an up-to-date status report of studies into the potential for top quark physics of lepton colliders with an energy reach that exceeds the top quark pair production threshold, with a focus on the linear collider projects ILC and CLIC. This summary shows that such projects can offer very competitive determinations of top quark properties (mass, width) and its interactions with other Standard Model particles, in particular electroweak gauge bosons and the Higgs boson. In both areas the prospects exceed the LHC potential significantly - often by an order of magnitude.

  3. LEP : the Large Electron Positron Collider Conference MT17

    CERN Multimedia

    2001-01-01

    LEP was CERN's flagship research facility from 1989 until 2000 when it stepped aside to make way for installation of the Laboratory's next major accelerator, the Large Hadron Collider, LHC. With a circumference of 27 kilometres, LEP was the largest circular particle collider in the world. Inside its beam pipe, about 100 metres underground, bunches of electrons and positrons raced around in opposite directions as they were accelerated to almost the speed of light. In its first phase of operation, LEP was designed to collide electrons and positrons at an energy of around 100 GeV. After some seven years of accumulating data at this energy to study the Z particle - electrically neutral carrier of the weak interaction - everything was done to boost the energy of LEP's beams as high as possible.

  4. Projects for ultra-high-energy circular colliders at CERN

    Science.gov (United States)

    Bogomyagkov, A. V.; Koop, I. A.; Levichev, E. B.; Piminov, P. A.; Sinyatkin, S. V.; Shatilov, D. N.; Benedict, M.; Oide, K.; Zimmermann, F.

    2016-12-01

    Within the Future Circular Collider (FCC) design study launched at CERN in 2014, it is envisaged to construct hadron (FCC-hh) and lepton (FCC-ee) ultra-high-energy machines aimed to replace the LHC upon the conclusion of its research program. The Budker Institute of Nuclear Physics is actively involved in the development of the FCC-ee electron-positron collider. The Crab Waist (CR) scheme of the collision region that has been proposed by INP and will be implemented at FCC-ee is expected to provide high luminosity over a broad energy range. The status and development of the FCC project are described, and its parameters and limitations are discussed for the lepton collider in particular.

  5. Lineshape of the Higgs boson in future lepton colliders

    Directory of Open Access Journals (Sweden)

    S. Jadach

    2016-04-01

    Full Text Available The effect of the photon emission (initial-state radiation in the cross section of the process of direct production of the Higgs boson in future high luminosity electron and muon colliders is calculated. It was found that the cross section at the top of the Higgs boson resonance peak is reduced by a factor 0.348 for the electron collider and 0.548 for the muon collider. A centre-of-mass energy spread of the centre-of-mass energy of 4.2 MeV (equal to the Higgs width would reduce peak cross section further, by a factor 0.170 and 0.256 (QED and energy spread for electron and muon beams respectively. Possible uncertainties in the resummed QED calculations are discussed. Numerical results for the lineshape cross section including QED and many values of the centre-of-mass energy spread are provided.

  6. Tevatron The Cinderella story or the art of collider

    CERN Document Server

    CERN. Geneva

    2007-01-01

    The Tevatron Collider at Fermilab (Batavia, IL, USA) is the world's highest energy particle collider at 1.8TeV c.m.e. The machine was a centerpiece of the US and world's High Energy Physics for many years. Currently, the Tevatron is in the last years of its operation in so-called Run II which started 2001 and is tentatively scheduled to end in 2010. In this lecture series, we'll try to learn from the exciting story of the Tevatron Collider Run II: the story of long preparations, great expectations, initial difficulties, years of "blood and sweat", continuous upgrades, exceeding its goals, high emotions, tune-up of accelerator organization for "combat fighting". The lectures will cover Introduction to the Tevatron, its history and Run II; "Plumbing" Issues; Beam Physics Issues; Luminosity Progress; Organization of Troops and Lessons for LHC.

  7. Muon-muon and other high energy colliders

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, R.B.; Gallardo, J.C. [Brookhaven National Lab., Upton, NY (United States). Center for Accelerator Physics

    1997-02-01

    The first section looks at the high energy physics advantages, disadvantages and luminosity requirements of hadron, of lepton and photon-photon colliders for comparison. The second section discusses the physics considerations for the muon collider. The third section covers muon collider components. The fourth section is about the intersection region and detectors. In the fifth section, the authors discuss modifications to enhance the muon polarization`s operating parameters with very small momentum spreads, operations at energies other than the maximum for which the machine is designed, and designs of machines for different maximum energies. The final section discusses a Research and Development plan aimed at the operation of a 0.5 TeV demonstration machine by the year 2010, and of the 4 TeV machine by the year 2020.

  8. Operational readiness verification, phase 1: A study on safety during outage and restart of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hollnagel, E. [Linkoeping Univ. (Sweden). Dept. of Computer and Information Science; Gauthereau, V. [Linkoeping Univ. (Sweden). Dept. of Industrial Engineering

    2001-06-01

    This report contains the findings from the first phase of a study on safety during outage and restart of nuclear power plants. Operational Readiness Verification (ORV) - in Swedish called Driftklarhetsverifiering (DKV) - refers to the test and verification activities that are necessary to ensure that plant systems are able to provide their required functions when needed - more concretely that all plant systems are in their correct functional state when the plant is restarted after an outage period. The concrete background for this work is that nine ORV related incidents were reported in Sweden between July 1995 and October 1998. The work reported here comprised a literature survey of research relevant for ORV issues, and an assessment of the present situation at Swedish NPPs with respect to ORV. The literature survey was primarily aimed at research related to NPPs, but also looked at domains where similar problems have occurred, such as maintenance in commercial aviation. The survey looked specifically for organisational and MTO aspects relevant to the present situation in Swedish NPPs. One finding was that ORV should be seen as an integral part of maintenance, rather than as a separate activity. Another, that there is a characteristic distribution of error modes for maintenance and ORV, with many sequence errors and omissions, rather than a set of unique error modes. An international study further showed that there are important differences in how procedures are used, and in the balance between decentralisation and centralisation. Several studies also suggested that ORV could usefully be described as a barrier system in relation to the flow of work, for instance using the following five stages: (1) preventive actions during maintenance/outage, (2) post-test after completion of work, (3) pre-test before start-up, (4) the start-up sequence itself, and (5) preventive actions during power operation - possibly including automatic safety systems. In the field survey

  9. A Complete Scheme of Ionization Cooling for a Muon Collider

    CERN Document Server

    Palmer, Robert B; Fernow, Richard C; Gallardo, Juan Carlos; Kirk, Harold G; Alexahin, Yuri; Neuffer, David; Kahn, Stephen Alan; Summers, Don

    2007-01-01

    A complete scheme for production and cooling a muon beam for three specified muon colliders is presented. Parameters for these muon colliders are given. The scheme starts with the front end of a proposed neutrino factory that yields bunch trains of both muon signs. Emittance exchange cooling in slow helical lattices reduces the longitudinal emittance until it becomes possible to merge the trains into single bunches, one of each sign. Further cooling in all dimensions is applied to the single bunches in further slow helical lattices. Final transverse cooling to the required parameters is achieved in 50 T solenoids using high Tc superconductor at 4 K. Preliminary simulations of each element are presented.

  10. Laser ion source for isobaric heavy ion collider experiment.

    Science.gov (United States)

    Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M

    2016-02-01

    Heavy-ion collider experiment in isobaric system is under investigation at Relativistic Heavy Ion Collider. For this experiment, ion source is required to maximize the abundance of the intended isotope. The candidate of the experiment is (96)Ru + (96)Zr. Since the natural abundance of particular isotope is low and composition of isotope from ion source depends on the composites of the target, an isotope enriched material may be needed as a target. We studied the performance of the laser ion source required for the experiment for Zr ions.

  11. Collider limits on new physics within micrOMEGAs

    CERN Document Server

    Barducci, D; Bernon, J; Boudjema, F; Da Silva, J; Kraml, S; Laa, U; Pukhov, A

    2016-01-01

    Results from the LHC put severe constraints on models of new physics. This includes constraints on the Higgs sector from the precise measurement of the mass and couplings of the 125~GeV Higgs boson, as well as limits from searches for other new particles. We present the procedure to use these constraints in micrOMEGAs by interfacing it to the external codes Lilith, HiggsSignals, HiggsBounds and SModelS. A few dedicated modules are also provided. With these new features, micrOMEGAs_4.3 provides a generic framework for evaluating dark matter observables together with collider and non-collider constraints.

  12. MIGHTY MURINES: NEUTRINO PHYSICS AT VERY HIGH ENERGY MUON COLLIDERS

    Energy Technology Data Exchange (ETDEWEB)

    KING,B.J.

    2000-05-05

    An overview is given of the potential for neutrino physics studies through parasitic use of the intense high energy neutrino beams that would be produced at future many-TeV muon colliders. Neutrino experiments clearly cannot compete with the collider physics. Except at the very highest energy muon colliders, the main thrust of the neutrino physics program would be to improve on the measurements from preceding neutrino experiments at lower energy muon colliders, particularly in the fields of B physics, quark mixing and CP violation. Muon colliders at the 10 TeV energy scale might already produce of order 10{sup 8} B hadrons per year in a favorable and unique enough experimental environment to have some analytical capabilities beyond any of the currently operating or proposed B factories. The most important of the quark mixing measurements at these energies might well be the improved measurements of the important CKM matrix elements {vert_bar}V{sub ub}{vert_bar} and {vert_bar}V{sub cb}{vert_bar} and, possibly, the first measurements of {vert_bar}V{sub td}{vert_bar} in the process of flavor changing neutral current interactions involving a top quark loop. Muon colliders at the highest center-of-mass energies that have been conjectured, 100--1,000 TeV, would produce neutrino beams for neutrino-nucleon interaction experiments with maximum center-of-mass energies from 300--1,000 GeV. Such energies are close to, or beyond, the discovery reach of all colliders before the turn-on of the LHC. In particular, they are comparable to the 314 GeV center-of-mass energy for electron-proton scattering at the currently operating HERA collider and so HERA provides a convenient benchmark for the physics potential. It is shown that these ultimate terrestrial neutrino experiments, should they eventually come to pass, would have several orders of magnitude more luminosity than HERA. This would potentially open up the possibility for high statistics studies of any exotic particles, such as

  13. Production of Electroweak Bosons at Hadron Colliders: Theoretical Aspects

    Science.gov (United States)

    Mangano, Michelangelo L.

    2016-10-01

    Since the W± and Z0 discovery, hadron colliders have provided a fertile ground, in which continuously improving measurements and theoretical predictions allow to precisely determine the gauge boson properties, and to probe the dynamics of electroweak and strong interactions. This article will review, from a theoretical perspective, the role played by the study, at hadron colliders, of electroweak boson production properties, from the better understanding of the proton structure, to the discovery and studies of the top quark and of the Higgs, to the searches for new phenomena beyond the Standard Model.

  14. Physics and technology of the Next Linear Collider

    CERN Document Server

    Kuhlman, S; Aiello, R; Akemoto, M; Alley, R; Assmann, R W; Baer, Howard W; Baltay, C; Bane, Karl Leopold Freitag; Barakat, B; Barker, A; Barklow, Timothy L; Barletta, W A; Bauer, D A; Bertolini, L R; Bharadwaj, V K; Bogart, J R; Bowden, G B; Bower, G; Brau, J E; Breidenbach, M; Brown, K L; Burke, D L; Burrows, P N; Byrd, J M; Cai, Y; Caryotakis, G; Cassel, R L; Chattopadhyay, S; Chen, P; Clark, S L; Cleaver, G B; Clem, D; Clendenin, J E; Corlett, J N; Corvin, C; Couture, G; Cuypers, F; Danielson, M; Deadrick, F J; Decker, Franz Josef; Donaldson, A R; Dragt, A J; Dubois, R; Early, R A; Ecklund, S D; Eichner, J; Einhorn, Martin B; Emma, P; Eppley, K R; Eriksson, L; Fahey, S; Farkas, Z D; Fawley, W M; Feng, J L; Fero, M J; Fisher, A S; Foundoulis, C; Fowkes, W R; Frey, R E; Frisch, J; Fuller, R W; Furman, M A; Genova, L F; Gintner, M; Giordano, G; Gluckstern, R L; Godfrey, S; Gold, S; Goluboff, M; Gross, G; Gunion, J F; Haber, Howard E; Han, T; Hanna, S; Hartman, S; Heifets, S A; Helm, R H; Hendrickson, L; Henestroza, E; Hertzbach, S S; Heusch, C A; Hewett, J L; Higashi, K; Higo, T; Hoag, H A; Hodgson, J; Hollebeek, R J; Holt, J A; Houck, T L; Humphrey, J W; Humphrey, R; Irwin, J; Jackson, A; Jacobsen, R A; Jaros, J A; Jobe, R Keith; Jones, R M; Kalyniak, P A; Kane, G L; Keller, L P; Kim, K J; Klem, D E; Ko, K; Koontz, R F; Kraft, E; Krejcik, P; Kroll, N M; Kubo, K; Kulikov, A; Lavine, T L; Li, H; Li, Z; Lidia, S M; Linebarger, W A; Loew, G A; Loewen, R J; Maeshima, K; Manly, S L; Marciano, W J; Markiewicz, T W; Maruyama, T; Mattison, T S; McDonald, K F; McKee, B; Messner, R; Meyerhofer, D D; Miller, R H; Minkowski, Peter; Minty, Michiko G; Moshammer, W; Munro, M H; Munroe, R; Murayama, H; Nantista, C D; Nauenberg, U; Nelson, E M; Nelson, H; Nelson, W R; Ng, C K; Nosochkov, Yu M; Ohgaki, T; Oide, K; Paige, Frank E; Palmer, D; Palmer, R B; Paterson, J M; Pearson, C; Perry, M; Peskin, Michael E; Phillips, R M; Phinney, N; Pope, R S; Raja, R; Raubenheimer, T O; Reginato, L; Rifkin, J; Riles, K; Rimmer, R A; Rinolfi, Louis; Rizzo, T; Robin, D; Rokni, S H; Ronan, Michael T; Rosenzweig, J; Ross, M C; Rowson, P C; Ruland, R E; Ruth, Ronald D; Saab, A; Sawyer, L; Schumm, B; Schwarz, H; Scott, B; Sessler, Andrew M; Sheppard, J C; Shoaee, H; Smith, S; Spence, W L; Spencer, C M; Spencer, J E; Sprehn, D; Strom, D; Stupakov, G; Takahashi, T; Tanaka, K; Tang, H; Tantawi, S G; Tata, Xerxes; Telnov, V I; Tenenbaum, P G; Thomas, S; Thompson, K A; Tian, F; Turner, J; Usher, T; Van Bibber, K; Van Kooten, R; Vanecek, D L; Vlieks, A E; Wagner, D L; Walz, D R; Wang, J W; Ward, B F L; Weidemann, A W; Westenskow, G A; White, T; Whittum, D H; Wilson, P B; Wilson, Z; Woodley, M; Woods, M; Wudka, J; Wurtele, J S; Xie, M; Yan, Y T; Yeremian, A D; Yokoya, K; Yu, S S; Zholents, A A; Zimmermann, Frank

    1996-01-01

    We present the current expectations for the design and physics program of an e+e- linear collider of center of mass energy 500 GeV -- 1 TeV. We review the experiments that would be carried out at this facility and demonstrate its key role in exploring physics beyond the Standard Model over the full range of theoretical possibilities. We then show the feasibility of constructing this machine, by reviewing the current status of linear collider technology and by presenting a precis of our `zeroth- order' design.

  15. Beam-Based Nonlinear Optics Corrections in Colliders

    CERN Document Server

    Pilat, Fulvia Caterina; Malitsky, Nikolay; Ptitsyn, Vadim

    2005-01-01

    A method has been developed to measure and correct operationally the non-linear effects of the final focusing magnets in colliders, which gives access to the effects of multi-pole errors by applying closed orbit bumps, and analyzing the resulting tune and orbit shifts. This technique has been tested and used during 3 years of RHIC (the Relativistic Heavy Ion Collider at BNL) operations. I will discuss here the theoretical basis of the method, the experimental set-up, the correction results, the present understanding of the machine model, the potential and limitations of the method itself as compared with other non linear correction techniques.

  16. ISR effects for resonant Higgs production at future lepton colliders

    CERN Document Server

    Greco, Mario; Liu, Zhen

    2016-01-01

    We study the effects of the initial state radiation on the $s$-channel Higgs boson resonant production at $\\mu^+\\mu^-$ and $e^+e^-$ colliders by convoluting with the beam energy spread profile of the collider and the Breit-Wigner resonance profile of the signal. We assess their impact on both the Higgs signal and SM backgrounds for the leading decay channels $h\\rightarrow b\\bar b,\\ WW^*$. Our study improves the existing analyses of the proposed future resonant Higgs factories and provides further guidance for the accelerator designs with respect to the physical goals.

  17. ISR effects for resonant Higgs production at future lepton colliders

    Science.gov (United States)

    Greco, Mario; Han, Tao; Liu, Zhen

    2016-12-01

    We study the effects of the initial state radiation on the s-channel Higgs boson resonant production at μ+μ- and e+e- colliders by convoluting with the beam energy spread profile of the collider and the Breit-Wigner resonance profile of the signal. We assess their impact on both the Higgs signal and SM backgrounds for the leading decay channels h → b b bar , WW*. Our study improves the existing analyses of the proposed future resonant Higgs factories and provides further guidance for the accelerator designs with respect to the physical goals.

  18. Prospects for collider searches for dark matter with heavy quarks

    Energy Technology Data Exchange (ETDEWEB)

    Artoni, Giacomo [Brandeis Univ., Waltham, MA (United States); Lin, Tongyan [Univ. of Chicago, IL (United States). Kavli Inst. for Cosmological Physics (KICP); Penning, Bjoern [Univ. of Chicago, IL (United States); Univ. of Chicago, IL (United States). Enrico Fermi Inst.; Sciolla, Gabriella [Brandeis Univ., Waltham, MA (United States); Venturini, Alessio [Brandeis Univ., Waltham, MA (United States)

    2013-08-05

    We present projections for future collider searches for dark matter produced in association with bottom or top quarks. Such production channels give rise to final states with missing transverse energy and one or more b-jets. Limits are given assuming an effective scalar operator coupling dark matter to quarks, where the dedicated analysis discussed here improves significantly over a generic monojet analysis. We give updated results for an anticipated high-luminosity LHC run at 14 TeV and for a 33 TeV hadron collider.

  19. Working group report: Physics at the Large Hadron Collider

    Indian Academy of Sciences (India)

    D K Ghosh; A Nyffeler; V Ravindran

    2011-05-01

    This is a summary of the activities of the Physics at the LHC working group in the XIth Workshop on High Energy Physics Phenomenology (WHEPP-XI) held at the Physical Research Laboratory, Ahmedabad, India in January 2010. We discuss the activities of each sub-working group on physics issues at colliders such as Tevatron and Large Hadron Collider (LHC). The main issues discussed involve (1) results on W mass measurement and associated QCD uncertainties, (2) an attempt to understand the asymmetry measured at Tevatron in the top quark production, and (3) phenomenology of warped space dimension model.

  20. Collider study on the loop-induced dark matter mediation

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Yuhsin, E-mail: yhtsai@umd.edu [Maryland Center for Fundamental Physics, University of Maryland, College Park, MD 20742 (United States)

    2016-06-21

    Collider experiments are one of the most promising ways to constrain Dark Matter (DM) interactions. For DM couplings involving light mediators, especially for the loop-mediated interactions, a meaningful interpretation of the results requires to go beyond effective field theory. In this note we discuss the study of the magnetic dipole interacting DM, focusing on a model with anarchic dark flavor structure. By including the momentum-dependent form factors that mediate the coupling – given by the Dark Penguin – in collider processes, we study bounds from monophoton, diphoton, and non-pointing photon searches at the LHC. We also compare our results to constraints from the direct detection experiments.