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Sample records for days lhc magnets

  1. Post-LHC accelerator magnets

    SciTech Connect

    Gourlay, Stephen A.

    2001-06-10

    The design and practicality of future accelerators, such as hadron colliders and neutrino factories being considered to supercede the LHC, will depend greatly on the choice of superconducting magnets. Various possibilities will be reviewed and discussed, taking into account recent progress and projected improvements in magnet design and conductor development along with the recommendations from the 2001 Snowmass workshop.

  2. LHC magnet quench protection system

    NASA Astrophysics Data System (ADS)

    Coull, L.; Hagedorn, D.; Remondino, V.; Rodriguez-Mateos, F.

    1994-07-01

    The quench protection system for the superconducting magnets of the CERN Large Hadron Collider (LHC) is described. The system is based on the so called 'cold diode' concept. In a group of series connected magnets if one magnet quenches then the magnetic energy of all the magnets will be dissipated in the quenched magnet so destroying it. This is avoided by by-passing the quenched magnet and then rapidly de-exciting the unquenched magnets. For the LHC machine it is foreseen to use silicon diodes situated inside the cryostat as by-pass elements - so called 'cold diodes'. The diodes are exposed to some 50 kGray of radiation during a 10 year operation life-time. The high energy density of the LHC magnets (500 kJ/m) coupled with the relatively slow propagation speed of a 'natural' quench (10 to 20 m/s) can lead to excessive heating of the zone where the quench started and to high internal voltages. It is therefore necessary to detect quickly the incipient quench and fire strip heaters which spread the quench out more quickly over a large volume of the magnet. After a quench the magnet chain must be de-excited rapidly to avoid spreading the quench to other magnets and over-heating the by-pass diode. This is done by switching high-power energy-dump resistors in series with the magnets. The LHC main ring magnet will be divided into 16 electrically separated units which has important advantages.

  3. US-LHC MAGNET DATABASE AND CONVENTIONS.

    SciTech Connect

    WEI,J.; MCCHESNEY,D.; JAIN,A.; PEGGS,S.; PILAT,F.; BOTTURA,L.; SABBI,G.

    1999-03-29

    The US-LHC Magnet Database is designed for production-magnet quality assurance, field and alignment error impact analysis, cryostat assembly assistance, and ring installation assistance. The database consists of tables designed to store magnet field and alignment measurements data and quench data. This information will also be essential for future machine operations including local IR corrections.

  4. LHC II system sensitivity to magnetic fluids

    NASA Astrophysics Data System (ADS)

    Cotae, Vlad; Creanga, Ioan

    2005-03-01

    Experiments have been designed to reveal the influences of ferrofluid treatment and static magnetic field exposure on the photosynthetic system II, where the light harvesting complex (LHC II) controls the ratio chlorophyll a/ chlorophyll b (revealing, indirectly, the photosynthesis rate). Spectrophotometric measurement of chlorophyll content revealed different influences for relatively low ferrofluid concentrations (10-30 μl/l) in comparison to higher concentrations (70-100 μl/l). The overlapped effect of the static magnetic field shaped better the stimulatory ferrofluid action on LHC II system in young poppy plantlets.

  5. High-field Magnet Development toward the High Luminosity LHC

    SciTech Connect

    Apollinari, Giorgio

    2014-07-01

    The upcoming Luminosity upgrade of the LHC (HL-LHC) will rely on the use of Accelerator Quality Nb3Sn Magnets which have been the focus of an intense R&D effort in the last decade. This contribution will describe the R&D and results of Nb3Sn Accelerator Quality High Field Magnets development efforts, with emphasis on the activities considered for the HL-LHC upgrades.

  6. Using tevatron magnets for HE-LHC or new ring in LHC tunnel

    SciTech Connect

    Piekarz, Henryk; /Fermilab

    2011-08-01

    Two injector accelerator options for HE-LHC of p{sup +} - p{sup +} collisions at 33 TeV cms energy are briefly outlined. One option is based on the Super-SPS (S-SPS) accelerator in the SPS tunnel, and the other one is based on the LER (Low-Energy-Ring) accelerator in the LHC tunnel. Expectations of performance of the main arc accelerator magnets considered for the construction of the S-SPS and of the LER accelerators are used to tentatively devise some selected properties of these accelerators as potential injectors to HE-LHC.

  7. Upgrade of the LHC magnet interconnections thermal shielding

    SciTech Connect

    Musso, Andrea; Barlow, Graeme; Bastard, Alain; Charrondiere, Maryline; Deferne, Guy; Dib, Gaëlle; Duret, Max; Guinchard, Michael; Prin, Hervé; Craen, Arnaud Vande; Villiger, Gilles; Chrul, Anna; Damianoglou, Dimitrios; Strychalski, Michał; Wright, Loren

    2014-01-29

    The about 1700 interconnections (ICs) between the Large Hadron Collider (LHC) superconducting magnets include thermal shielding at 50-75 K, providing continuity to the thermal shielding of the magnet cryostats to reduce the overall radiation heat loads to the 1.9 K helium bath of the magnets. The IC shield, made of aluminum, is conduction-cooled via a welded bridge to the thermal shield of the adjacent magnets which is actively cooled. TIG welding of these bridges made in the LHC tunnel at installation of the magnets induced a considerable risk of fire hazard due to the proximity of the multi-layer insulation of the magnet shields. A fire incident occurred in one of the machine sectors during machine installation, but fortunately with limited consequences thanks to prompt intervention of the operators. LHC is now undergoing a 2 years technical stop during which all magnet's ICs will have to be opened to consolidate the magnet electrical connections. The IC thermal shields will therefore have to be removed and re-installed after the work is completed. In order to eliminate the risk of fire hazard when re-welding, it has been decided to review the design of the IC shields, by replacing the welded bridges with a mechanical clamping which also preserves its thermal function. An additional advantage of this new solution is the ease in dismantling for maintenance, and eliminating weld-grinding operations at removal needing radioprotection measures because of material activation after long-term operation of the LHC. This paper describes the new design of the IC shields and in particular the theoretical and experimental validation of its thermal performance. Furthermore a status report of the on-going upgrade work in the LHC is given.

  8. Upgrade of the LHC magnet interconnections thermal shielding

    NASA Astrophysics Data System (ADS)

    Musso, Andrea; Barlow, Graeme; Bastard, Alain; Charrondiere, Maryline; Chrul, Anna; Damianoglou, Dimitrios; Deferne, Guy; Dib, Gaëlle; Duret, Max; Guinchard, Michael; Prin, Hervé; Strychalski, Michał; Craen, Arnaud Vande; Villiger, Gilles; Wright, Loren

    2014-01-01

    The about 1700 interconnections (ICs) between the Large Hadron Collider (LHC) superconducting magnets include thermal shielding at 50-75 K, providing continuity to the thermal shielding of the magnet cryostats to reduce the overall radiation heat loads to the 1.9 K helium bath of the magnets. The IC shield, made of aluminum, is conduction-cooled via a welded bridge to the thermal shield of the adjacent magnets which is actively cooled. TIG welding of these bridges made in the LHC tunnel at installation of the magnets induced a considerable risk of fire hazard due to the proximity of the multi-layer insulation of the magnet shields. A fire incident occurred in one of the machine sectors during machine installation, but fortunately with limited consequences thanks to prompt intervention of the operators. LHC is now undergoing a 2 years technical stop during which all magnet's ICs will have to be opened to consolidate the magnet electrical connections. The IC thermal shields will therefore have to be removed and re-installed after the work is completed. In order to eliminate the risk of fire hazard when re-welding, it has been decided to review the design of the IC shields, by replacing the welded bridges with a mechanical clamping which also preserves its thermal function. An additional advantage of this new solution is the ease in dismantling for maintenance, and eliminating weld-grinding operations at removal needing radioprotection measures because of material activation after long-term operation of the LHC. This paper describes the new design of the IC shields and in particular the theoretical and experimental validation of its thermal performance. Furthermore a status report of the on-going upgrade work in the LHC is given.

  9. Testing beam-induced quench levels of LHC superconducting magnets

    NASA Astrophysics Data System (ADS)

    Auchmann, B.; Baer, T.; Bednarek, M.; Bellodi, G.; Bracco, C.; Bruce, R.; Cerutti, F.; Chetvertkova, V.; Dehning, B.; Granieri, P. P.; Hofle, W.; Holzer, E. B.; Lechner, A.; Nebot Del Busto, E.; Priebe, A.; Redaelli, S.; Salvachua, B.; Sapinski, M.; Schmidt, R.; Shetty, N.; Skordis, E.; Solfaroli, M.; Steckert, J.; Valuch, D.; Verweij, A.; Wenninger, J.; Wollmann, D.; Zerlauth, M.

    2015-06-01

    In the years 2009-2013 the Large Hadron Collider (LHC) has been operated with the top beam energies of 3.5 and 4 TeV per proton (from 2012) instead of the nominal 7 TeV. The currents in the superconducting magnets were reduced accordingly. To date only seventeen beam-induced quenches have occurred; eight of them during specially designed quench tests, the others during injection. There has not been a single beam-induced quench during normal collider operation with stored beam. The conditions, however, are expected to become much more challenging after the long LHC shutdown. The magnets will be operating at near nominal currents, and in the presence of high energy and high intensity beams with a stored energy of up to 362 MJ per beam. In this paper we summarize our efforts to understand the quench levels of LHC superconducting magnets. We describe beam-loss events and dedicated experiments with beam, as well as the simulation methods used to reproduce the observable signals. The simulated energy deposition in the coils is compared to the quench levels predicted by electrothermal models, thus allowing one to validate and improve the models which are used to set beam-dump thresholds on beam-loss monitors for run 2.

  10. The LHC magnet system and its status of development

    NASA Technical Reports Server (NTRS)

    Bona, Maurizio; Perin, Romeo; Vlogaert, Jos

    1995-01-01

    CERN is preparing for the construction of a new high energy accelerator/collider, the Large Hadron Collider (LHC). This new facility will mainly consist of two superconducting magnetic beam channels, 27 km long, to be installed in the existing LEP tunnel. The magnetic system comprises about 1200 twin-aperture dipoles, 13.145 m long, with an operational field of 8.65 T, about 600 quadrupoles, 3 m long, and a very large number of other superconducting magnetic components. A general description of the system is given together with the main features of the design of the regular lattice magnets. The paper also describes the present state of the magnet R & D program. Results from short model work, as well as from full scale prototypes will be presented, including the recently tested 10 m long full-scale prototype dipole manufactured in industry.

  11. A Cryogenic test stand for LHC quadrupole magnets

    SciTech Connect

    R. J. Rabehl et al.

    2004-03-09

    A new test stand for testing LHC interaction region (IR) quadrupole magnets at the Fermilab Magnet Test Facility has been designed and operated. The test stand uses a double bath system with a lambda plate to provide the magnet with a stagnant bath of pressurized He II at 1.9 K and 0.13 MPa. A cryostated magnet 0.91 m in diameter and up to 13 m in length can be accommodated. This paper describes the system design and operation. Issues related to both 4.5 K and 1.9 K operations and magnet quenching are highlighted. An overview of the data acquisition and cryogenics controls systems is also included.

  12. TEST RESULTS FOR LHC INSERTION REGION DEPOLE MAGNETS.

    SciTech Connect

    MURATORE, J.; JAIN, A.; ANERELLA, M.; COSSOLINO, J.; ET AL.

    2005-05-16

    The Superconducting Magnet Division at Brookhaven National Laboratory (BNL) has made 20 insertion region dipoles for the Large Hadron Collider (LHC) at CERN. These 9.45 m-long, 8 cm aperture magnets have the same coil design as the arc dipoles now operating in the Relativistic Heavy Ion Collider (RHIC) at BNL and are of single aperture, twin aperture, and double cold mass configurations. They are required to produce fields up to 4.14 T for operation at 7.56 TeV. Eighteen of these magnets have been tested at 4.5 K using either forced flow supercritical helium or liquid helium. The testing was especially important for the twin aperture models, whose construction was very different from the RHIC dipoles, except for the coil design. This paper reports on the results of these tests, including spontaneous quench performance, verification of quench protection heater operation, and magnetic field quality.

  13. Contextualized magnetism in secondary school: learning from the LHC (CERN)

    NASA Astrophysics Data System (ADS)

    Cid, Ramón

    2005-07-01

    Physics teachers in secondary schools usually mention the world's largest particle physics laboratory—CERN (European Organization for Nuclear Research)—only because of the enormous size of the accelerators and detectors used there, the number of scientists involved in their activities and also the necessary international scientific collaboration. Impressive pictures of the accelerators and detectors are also shown. This is correct but clearly incomplete since there are other didactic possibilities to explore while talking about one of the most important scientific institutions in the world. The aim of this article is to introduce a few simple physical calculations about some magnetic phenomena that took place in old accelerators and will be present when the LHC (Large Hadron Collider) starts working in 2007. They can be used in the classroom in order to stimulate the curiosity of students, to help them to understand those physical concepts, and as an example of the relationship between the 'cold equations' of physics on the blackboard and the exciting work in scientific research.

  14. Spatial distributions of magnetic field in the RHIC and LHC energy regions

    NASA Astrophysics Data System (ADS)

    Zhong, Yang; Yang, Chun-Bin; Cai, Xu; Feng, Sheng-Qin

    2015-10-01

    Relativistic heavy-ion collisions can produce extremely strong magnetic fields in the collision regions. The spatial variation features of the magnetic fields are analyzed in detail for non-central Pb-Pb collisions at LHC at \\sqrt{s_NN}=900, 2760 and 7000 GeV and Au-Au collisions at RHIC at \\sqrt{s_NN}=62.4, 130 and 200 GeV. The dependencies of magnetic field on proper time, collision energies and impact parameters are investigated in this paper. It is shown that an enormous and highly inhomogeneous spatial distribution magnetic field can indeed be created in off-centre relativistic heavy-ion collisions in RHIC and LHC energy regions. The enormous magnetic field is produced just after the collision, and the magnitude of magnetic field of the LHC energy region is larger than that of the RHIC energy region at small proper time. It is found that the magnetic field in the LHC energy region decreases more quickly with the increase of proper time than that of the RHIC energy region. Supported by National Natural Science Foundation of China (11375069, 11435054, 11075061, 11221504) and Key Laboratory foundation of Quark and Lepton Physics (Hua-Zhong Normal University) (QLPL2014P01)

  15. Magnetic field measurements of LHC inner triplet quadrupoles fabricated at Fermilab

    SciTech Connect

    Velev, G.V.; Bossert, R.; Carcagno, R.; DiMarco, J.; Feher, S.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Orris, D.; Schlabach, P.; Strait, J.; /Fermilab

    2006-08-01

    Fermilab, as part of the US-LHC Accelerator Project, is producing superconducting low-beta quadrupole magnets for the Large Hadron Collider (LHC). These 5.5 m long magnets are designed to operate in superfluid helium at 1.9 K with a nominal gradient of 205 T/m in the 70 mm bore. Two quadrupoles separated by a dipole orbit corrector in a single cryogenic assembly comprise the Q2 optical elements of the final focus triplets in the LHC interaction regions. The field quality of the quadrupoles is measured at room temperature during construction of the cold masses as well as during cold testing of the cryogenic assembly. We summarize data from the series measurements of the magnets and discuss various topics of interest.

  16. Single-pass beam measurements for the verification of the LHC magnetic model

    SciTech Connect

    Calaga, R.; Giovannozzi, M.; Redaelli, S.; Sun, Y.; Tomas, R.; Venturini-Delsolaro, W.; Zimmermann, F.

    2010-05-23

    During the 2009 LHC injection tests, the polarities and effects of specific quadrupole and higher-order magnetic circuits were investigated. A set of magnet circuits had been selected for detailed investigation based on a number of criteria. On or off-momentum difference trajectories launched via appropriate orbit correctors for varying strength settings of the magnet circuits under study - e.g. main, trim and skew quadrupoles; sextupole families and spool piece correctors; skew sextupoles, octupoles - were compared with predictions from various optics models. These comparisons allowed confirming or updating the relative polarity conventions used in the optics model and the accelerator control system, as well as verifying the correct powering and assignment of magnet families. Results from measurements in several LHC sectors are presented.

  17. Instrumentation status of the low-b magnet systems at the Large Hadron Collider (LHC)

    SciTech Connect

    Darve, C.; Balle, C.; Casas-Cubillos, J.; Perin, A.; Vauthier, N.; /CERN

    2011-05-01

    The low-{beta} magnet systems are located in the Large Hadron Collider (LHC) insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process allowing proton collisions at luminosity up to 10{sup 34}cm{sup -2}s{sup -1}. Those systems are a contribution of the US-LHC Accelerator project. The systems are mainly composed of the quadrupole magnets (triplets), the separation dipoles and their respective electrical feed-boxes (DFBX). The low-{beta} magnet systems operate in an environment of extreme radiation, high gradient magnetic field and high heat load to the cryogenic system due to the beam dynamic effect. Due to the severe environment, the robustness of the diagnostics is primordial for the operation of the triplets. The hardware commissioning phase of the LHC was completed in February 2010. In the sake of a safer and more user-friendly operation, several consolidations and instrumentation modifications were implemented during this commissioning phase. This paper presents the instrumentation used to optimize the engineering process and operation of the final focusing/defocusing quadrupole magnets for the first years of operation.

  18. Optics implications of implementing Nb3Sn magnets in the LHC phase 1 upgrade

    SciTech Connect

    Johnstone, J.A.; Kashikhin, V.V.; Mokhov, N.V.; Zlobin, A.V.; /Fermilab

    2008-06-01

    CERN has encouraged the US-LARP collaboration to participate in Phase I of the LHC luminosity upgrade by analyzing the benefits gained by using Nb3Sn technology to replace the functionality of select NbTi magnets that CERN is committed to construct. Early studies have shown that the much higher gradients (shorter magnetic lengths) and temperature margins (quench stability) of Nb3Sn magnets compared to their NbTi counterparts is favorable--allowing the insertion of additional absorbers between Q1 and Q2, for example. This paper discusses the relative merits of the NbTi and Nb3Sn options.

  19. Steady State Heat Deposits Modeling in the Nb3Sn Quadrupole Magnets for the Upgrade of the LHC Inner Triplet

    SciTech Connect

    Bocian, D.; Ambrosio, G.; Felice, H.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidze, G.; Dietderich, D.; Feher, S.; Ferracin, P.; Hafalia, R.; /Fermilab /Lawrence Berkeley Lab /Brookhaven

    2011-09-01

    In hadron colliders such as the LHC, the energy deposited in the superconductors by the particles lost from the beams or coming from the collision debris may provoke quenches detrimental to the accelerator operation. In previous papers, a Network Model has been used to study the thermodynamic behavior of magnet coils and to calculate the quench levels in the LHC magnets for expected beam loss profiles. This model was subsequently used for thermal analysis and design optimization of Nb{sub 3}Sn quadrupole magnets, which LARP (US LHC Accelerator Research Program) is developing for possible use in the LHC luminosity upgrade. For these new magnets, the heat transport efficiency from the coil to the helium bath needs to be determined and optimized. In this paper the study of helium cooling channels and the heat evacuation scheme are presented and discussed.

  20. Preliminary study of using pipetron-type magnets for a pre-accelerator for the LHC

    SciTech Connect

    de Rijk, G.; Rossi, L.; Piekarz, H.; /Fermilab

    2006-06-01

    One of the luminosity limitations of the LHC is the rather low injection energy (0.45 TeV) with respect to the collision energy (7 TeV). The magnetic multipoles in the main dipoles at low field and their dynamic behavior are considered to limit the achievable bunch intensity and emittance. We report on a preliminary study to increase the injection energy to 1.5 TeV using a two-beam pre-accelerator (LER) in the LHC tunnel. The LER is based on ''Pipetron'' magnets as originally proposed for the VLHC. The aim of the study is to assess the feasibility and to identify the critical processes or systems that need to be investigated and developed to render such a machine possible.

  1. Electrical performance of a string of magnets representing a half-cell of the LHC machine

    SciTech Connect

    Rodriguez-Mateos, F.; Coull, L.; Dahlerup-Petersen, K.; Hagedorn, D.; Krainz, G.; Rijllart, A.; McInturff, A.

    1995-06-21

    Tests have been carried out on a string prototype superconducting magnets, consisting of one double-quadrupole and two double-dipoles forming the major part of a half-cell of the LHC machine. The magnets are protected individually by ``cold diodes`` and quench heaters. The electrical aspects of these tests are described here. The performance during quench of the protection diodes and the associated interconnections was studied. Tests determined the magnet quench performance in training and at different ramp-rates, and investigated the inter-magnet propagation of quenches. Current lead and inter-magnet contact resistances were controlled and the performance of the power converter and the dump switches assessed.

  2. Performance of the cold powered diodes and diode leads in the main magnets of the LHC

    NASA Astrophysics Data System (ADS)

    Willering, G. P.; Giloux, C.; Bajko, M.; Bednarek, M.; Bottura, L.; Charifoulline, Z.; Dahlerup-Petersen, K.; Dib, G.; D'Angelo, G.; Gharib, A.; Grand-Clement, L.; Izquierdo Bermudez, S.; Prin, H.; Roger, V.; Rowan, S.; Savary, F.; Tock, J.-Ph; Verweij, A.

    2015-12-01

    During quench tests in 2011 variations in resistance of an order of magnitude were found in the diode by-pass circuit of the main LHC magnets. An investigation campaign was started to understand the source, the occurrence and the impact of the high resistances. Many tests were performed offline in the SM18 test facility with a focus on the contact resistance of the diode to heat sink contact and the diode wafer temperature. In 2014 the performance of the diodes and diode leads of the main dipole bypass systems in the LHC was assessed during a high current qualification test. In the test a current cycle similar to a magnet circuit discharge from 11 kA with a time constant of 100 s was performed. Resistances of up to 600 μΩ have been found in the diode leads at intermediate current, but in general the high resistances decrease at higher current levels and no sign of overheating of diodes has been seen and the bypass circuit passed the test. In this report the performance of the diodes and in particular the contact resistances in the diode leads are analysed with available data acquired over more than 10 years from acceptance test until the main dipole training campaign in the LHC in 2015.

  3. Experimental 11.5 T Nb3Sn LHC type of dipole magnet

    NASA Astrophysics Data System (ADS)

    den Ouden, A.; Wessel, S.; Krooshoop, E.; Dubbeldam, R.; Ten Kate, H. H. J.

    1994-07-01

    As part of the magnet development program for the LHC an experimental 1 m long 11.5 T single aperture Nb3Sn dipole magnet has been designed and is now under construction. The design is focused on full utilisation of the high current density in the powder tube Nb3Sn. A new field optimisation has led to a different winding layout and cable sizes as compared to the reference LHC design. Another important feature of the design is the implementation of a shrink fit ring collar system. An extensive study of the critical current of the Nb3Sn cables as a function of the transverse stress on the cables shows a permanent degradation by the cabling process of about 20%, still leaving a safety margin at the operation field of 11.5 T of 15%. A revised glass/mica glass insulation system is applied which improves the thermal conductivity of the windings as well as the impregnation process considerably. This paper describes various design and production details of the magnet system as well as component tests.

  4. Structure for an LHC 90mm Nb3Sn Quadrupole Magnet

    SciTech Connect

    Hafalia, A.R.; Caspi, S.; Bartlett, S.E.; Dietderich, D.R.; Ferracin, P.; Gourlay, S.A.; Hannaford, C.R.; Higley, H.; Lietzke, A.F.; Lau, B.; Liggins, N.; Mattafirri, S.; McInturff, A.D.; Nyman, M.; Sabbi,G.L.; Scanlan, R.M.; Swanson, J.

    2005-04-16

    A full-scale mechanical model of the LHC Nb{sub 3}Sn quadrupole magnet structure has been designed, built and tested. The structure will support a 90mm bore, 1m long magnet prototype as part of the US LHC Accelerator Research Program (LARP). The structure utilizes Bladder and Key Technology to control and transfer pre-stress from an outer aluminum shell to an inner coil. Axial aluminum rods take care of pre-stress at the ends--ensuring that the coil is fully constrained along all three axes. The outer aluminum shell and an inner ''dummy coil'' (aluminum tube) were extensively instrumented with strain gauges. The gauges were used to monitor and map the effectiveness of the stress relation between the loading structure and a ''dummy'' coil through varying mechanical load conditions --from bladder and key pre-stress at room temperature through cool-down. Test results of the stress distribution in the structure and the in dummy coil is reported and compared with expected results calculated with the structural analysis program ANSYS.

  5. Status of the Consolidation of the LHC Superconducting Magnets and Circuits

    NASA Astrophysics Data System (ADS)

    Tock, J. Ph; Atieh, S.; Bodart, D.; Bordry, F.; Bourcey, N.; Cruikshank, P.; Dahlerup-Petersen, K.; Dalin, J. M.; Garion, C.; Musso, A.; Ostojic, R.; Perin, A.; Pojer, M.; Savary, F.; Scheuerlein, C.

    2014-05-01

    The first LHC long shutdown (LS1) started in February 2013. It was triggered by the need to consolidate the 13 kA splices between the superconducting magnets to allow the LHC to reach safely its design energy of 14 TeV center of mass. The final design of the consolidated splices is recalled. 1695 interconnections containing 10 170 splices have to be opened. In addition to the work on the 13 kA splices, the other interventions performed during the first long shut-down on all the superconducting circuits are described. All this work has been structured in a project, gathering about 280 persons. The opening of the interconnections started in April 2013 and consolidation works are planned to be completed by August 2014. This paper describes first the preparation phase with the building of the teams and the detailed planning of the operation. Then, it gives feedback from the worksite, namely lessons learnt and adaptations that were implemented, both from the technical and organizational points of view. Finally, perspectives for the completion of this consolidation campaign are given.

  6. What is Common in the Training of the Large Variety of Impregnated Corrector Magnets for the LHC

    NASA Astrophysics Data System (ADS)

    Ijspeert, Albert; Ten Kate, Herman

    2004-06-01

    The Large Hadron Collider (LHC) will be equipped with about 5000 superconducting corrector magnets of 10 different types, ranging from dipoles through quadrupoles, sextupoles and octupoles to decapoles and dodecapoles. Four wires are used with 2 copper/superconductor ratios. Magnet lengths range from 0.15 m to 1.4 m. However, the magnets are all epoxy-impregnated and wound with enameled monolithic wires. The paper highlights the features that are common in the training of all these different magnets and uses that to give some clues for the possible origin of the training.

  7. A Warm Bore Anticryostat for Series Magnetic Measurements of LHC Superconducting Dipole and Short-Straight-Section Magnets

    NASA Astrophysics Data System (ADS)

    Dunkel, O.; Legrand, P.; Sievers, P.

    2004-06-01

    All LHC twin aperture magnets will be tested under operating conditions to verify their performance. The field measurement equipment works at ambient temperature and pressure. Each magnet is therefore equipped with two warm bore anticryostats. As a consequence a total of nearly 80 anticryostats of different lengths have to be assembled, handled and serviced during the test period. Two main constraints determine the frame for the design of these anticryostats: inside a given beam pipe aperture of 50 mm kept at 1.9 K, a warm bore aperture of 40 mm must provide the highest possible mechanical stability and robustness for numerous mounting cycles as well as the lowest possible heat losses towards the cryogenic system. In addition, compatibility with high magnetic fields and an insulation vacuum of about 10-7 mbar have to be maintained. This paper describes how a satisfactory mechanical stability as well as heat losses in the order of 0.8 W/m are achieved with a design based on very careful space and material optimization. Other aspects like assembly, installation, thermal behavior and temperature control during the operation are described.

  8. The LHC Vacuum System

    NASA Astrophysics Data System (ADS)

    Gröbner, O.

    1997-05-01

    The Large Hadron Collider (LHC) at CERN, involves two proton storage rings with colliding beams of 7 TeV. The machine will be housed in the existing LEP tunnel and requires 16 m long superconducting bending magnets. The vacuum chamber will be the inner wall of the cryostat and hence at the temperature of the magnet cold bore, i.e. at 1.9 K and therefore a very good cryo-pump. To reduce the cryogenic power consumption, the heat load from synchrotron radiation and from the image currents in the vacuum chamber will be absorbed on a 'beam screen', which operates between 5 and 20 K, inserted in the magnet cold bore. The design pressure necessary for operation must provide a lifetime of many days and a stringent requirement comes from the power deposition in the superconducting magnet coils due to protons scattered on the residual gas which could lead to a magnet quench. Cryo-pumping of gas on the cold surfaces provides the necessary low gas densities but it must be ensured that the vapour pressure of cryo-sorbed molecules, of which H2 and He would be the most critical species, remains within acceptable limits. The room temperature sections of the LHC, specifically in the experiments, the vacuum must be stable against ion induced desorption and ISR-type 'pressure bumps'.

  9. Yukawa coupling and anomalous magnetic moment of the muon: An update for the LHC era

    SciTech Connect

    Crivellin, Andreas; Girrbach, Jennifer; Nierste, Ulrich

    2011-03-01

    We study the interplay between a soft muon Yukawa coupling generated radiatively with the trilinear A-terms of the minimal supersymmetric standard model (MSSM) and the anomalous magnetic moment of the muon. In the absence of a tree-level muon Yukawa coupling the lightest smuon mass is predicted to be in the range between 600 GeV and 2200 GeV at 2{sigma}, if the bino mass M{sub 1} is below 1 TeV. Therefore, a detection of a smuon (in conjunction with a sub-TeV bino) at the LHC would directly imply a nonzero muon Yukawa coupling in the MSSM superpotential. Inclusion of slepton flavor mixing could in principle lower the mass of one smuonlike slepton below 600 GeV. However, the experimental bounds on radiative lepton decays instead strengthen the lower mass bound, with larger effects for smaller M{sub 1}, We also extend the analysis to the electron case and find that a light selectron close to the current experimental search limit may prove the MSSM electron Yukawa coupling to be nonzero.

  10. Day-to-day variability of the magnetic field measurements, preliminary results from MAGDAS chain in Egypt

    NASA Astrophysics Data System (ADS)

    Mahrous, Ayman; El-Gamry, Essam; Faheem, Amin; El-Hawary, Reham; Yumoto, Kiyohumi

    MAGDAS, the Magnetic Data Acquisition System, was successfully installed at two stations in Egypt. The first station located at Fayoum prefecture, while the second station located in South Valley at Aswan prefecture. We studied preliminary results obtained from the variability of the amplitude of diurnal variations of the solar quiet (Sq) in the three geomagnetic elements, H, D, Z. The day-to-day fluctuations of the horizontal, declination and vertical component of the geomagnetic field along MAGDAS chain in Egypt were examined. The magnetic data obtained from Fayoum and Aswan gives a good representation of the geomagnetic field at low-latitude stations.

  11. The possibility to measure the magnetic moments of short-lived particles (charm and beauty baryons) at LHC and FCC energies using the phenomenon of spin rotation in crystals

    NASA Astrophysics Data System (ADS)

    Baryshevsky, V. G.

    2016-06-01

    The use of spin rotation effect in bent crystals for measuring the magnetic moment of short-lived particles in the range of LHC and FCC energies is considered. It is shown that the estimated number of produced baryons that are captured into a bent crystal grows as ∼γ 3 / 2 with increasing particle energy. Hence it may be concluded that the experimental measurement of magnetic moments of short-lived particles using the spin rotation effect is feasible at LHC and higher energies (for LHC energies, e.g., the running time required for measuring the magnetic moment of Λc+is 2 ÷ 16 hours).

  12. The possibility to measure the magnetic moments of short-lived particles (charm and beauty baryons) at LHC and FCC energies using the phenomenon of spin rotation in crystals

    NASA Astrophysics Data System (ADS)

    Baryshevsky, V. G.

    2016-06-01

    The use of spin rotation effect in bent crystals for measuring the magnetic moment of short-lived particles in the range of LHC and FCC energies is considered. It is shown that the estimated number of produced baryons that are captured into a bent crystal grows as ∼γ 3 / 2 with increasing particle energy. Hence it may be concluded that the experimental measurement of magnetic moments of short-lived particles using the spin rotation effect is feasible at LHC and higher energies (for LHC energies, e.g., the running time required for measuring the magnetic moment of Λc+ is 2 ÷ 16 hours).

  13. Test Results of 15 T Nb3Sn Quadrupole Magnet HQ01 with a 120 mm Bore for the LHC Luminosity Upgrade

    SciTech Connect

    Caspi, S.; Schmalzle, J.; Ambrosio, G.; Anerella, M.; Barzi, E.; Bingham, B.; Bossert, R.; Cheng, D.W.; Chlachidze, G.; Dietderich, D.R.; Felice, H.; Ferracin, P.; Ghosh, A.; Hafalia, A.R.; Hannaford, C.R.; Joseph, J.; Kashikhin, V.V.; Sabbi, G.L.; Schmalzle, J.; Wanderer,; P.l Xiaorong, W.; Zlobin, A.V.

    2011-08-03

    In support of the luminosity upgrade of the Large Hadron Collider (LHC), the US LHC Accelerator Research Program (LARP) has been developing a 1-meter long, 120 mm bore Nb{sub 3}Sn IR quadrupole magnet (HQ). With a short sample gradient of 219 T/m at 1.9 K and a conductor peak field of 15 T, the magnet will operate under higher forces and stored-energy levels than that of any previous LARP magnet models. In addition, HQ has been designed to incorporate accelerator quality features such as precise coil alignment and adequate cooling. The first 6 coils (out of the 8 fabricated so far) have been assembled and used in two separate tests-HQ01a and HQ01b. This paper presents design parameters, summary of the assemblies, the mechanical behavior as well as the performance of HQ01a and HQ01b.

  14. The Bastille Day Magnetic Clouds and Upstream Shocks: Near Earth Interplanetary Observations

    NASA Technical Reports Server (NTRS)

    Lepping, R. P.; Berdichevsky, D. B.; Burlaga, L. F.; Lazarus, A. J.; Kasper, J.; Desch, M. D.; Wu, C.-C.; Reames, D. V.; Singer, H. J.; Singer, H. J.; Vondrak, Richard R. (Technical Monitor)

    2001-01-01

    The energetic charged particle, interplanetary magnetic field, and plasma characteristics of the 'Bastille Day' shock and ejecta/magnetic cloud events at 1 AU occurring over the days 14-16 July 2000 are described. Profiles of MeV (WIND/LEMT) energetic ions help to organize the overall sequence of events from the solar source to 1 AU. Stressed are analyses of an outstanding magnetic cloud (MC2) starting late on 15 July and its upstream shock about 4 hours earlier in WIND magnetic field and plasma data. Also analyzed is a less certain, but likely, magnetic cloud (MC1) occurring early on 15 July; this was separated from MC2 by its upstream shock and many heliospheric current sheet (HCS) crossings. Other HCS crossings occurred throughout the 3-day period. Overall this dramatic series of interplanetary events caused a large multi-phase magnetic storm with min Dst lower than -300 nT. The very fast solar wind speed (greater than or equal to 1100 km/s) in and around the front of MC2 (for near average densities) was responsible for a very high solar wind ram pressure driving in the front of the magnetosphere to geocentric distances estimated to be as low as approx. 5 R(sub E), much lower than the geosynchronous orbit radius. This was consistent with magnetic field observations from two GOES satellites which indicated they were in the magnetosheath for extended times. A static force free field model is used to fit the two magnetic cloud profiles providing estimates of the clouds' physical and geometrical properties. MC2 was much larger than MCI, but their axes were nearly antiparallel, and their magnetic fields had the same left-handed helicity. MC2's axis and its upstream shock normal were very close to being perpendicular to each other, as might be expected if the cloud were driving the shock at the time of observation. The estimated axial magnetic flux carried by MC2 was 52 x 10(exp 20) Mx, which is about 5 times the typical magnetic flux estimated for other magnetic

  15. Nb$_3$Sn High Field Magnets for the High Luminosity LHC Upgrade Project

    SciTech Connect

    Ambrosio, Giorgio

    2015-01-01

    The High Luminosity upgrade of the Large Hadron Collider at CERN requires a new generation of high field superconducting magnets. High field large aperture quadrupoles (MQXF) are needed for the low-beta triplets close to the ATLAS and CMS detectors, and high field two-in-one dipoles (11 T dipoles) are needed to make room for additional collimation. The MQXF quadrupoles, with a field gradient of 140 T/m in 150 mm aperture, have a peak coil field of 12.1 T at nominal current. The 11 T dipoles, with an aperture of 60 mm, have a peak coil field of 11.6 T at nominal current. Both magnets require Nb3Sn conductor and are the first applications of this superconductor to actual accelerator magnets.

  16. Design optimization of a 0.1-ton/day active magnetic regenerative hydrogen liquefier

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Sherif, S. A.; DeGregoria, A. J.; Zimm, C. B.; Veziroglu, T. N.

    2000-04-01

    A design optimization procedure of a 0.1-ton/day active magnetic regenerative (AMR) hydrogen liquefier model is described. The liquefier is proposed for the industrial liquid hydrogen market with overall efficiency being the primary measure of performance. This performance is described here in terms of particle size, bed length, and inter-stage temperature. Efficiency comparable to larger gas cycle plants is predicted. The magnetic liquefier may be modified to operate as a two-stage magnetic refrigerator between 77 and 20 K with high efficiency. The paper describes an optimization method as applied to the design of a two-stage AMR hydrogen liquefier and presents the associated results. A five-parameter optimization process is performed since there are five changeable parameters; the low- and high-stage particle sizes, the low- and high-stage bed lengths, and the inter-stage temperature. Model results are presented and compared with experimental results of an actual liquefier.

  17. Correlation of the 27-day variation of cosmic rays to the interplanetary magnetic field strength

    NASA Astrophysics Data System (ADS)

    Sabbah, I.

    2001-08-01

    We analyze cosmic ray data as well as interplanetary magnetic field (IMF) data, to examine the relation and correlation between their 27-day variations during the time interval 1965-1995. The amplitude of the 27day variation of galactic cosmic rays is linearly correlated with: the IMF strength (B), the z-component (Bz) of the IMF vector and the product of the solar wind speed (V) times B (VB). It is well correlated with the heliospheric current sheet tiltangle.Thecross-correlationfunctionofthe27-daycosmic ray variation versus the solar wind speed shows a negative correlation. The solar wind speed leads the cosmic ray variation by 2 years. The 27-day variation of cosmic rays is correlated with the variation in both the xand y-components of the IMF, it lags with 3-5 years. 1. Introduction Galactic cosmic rays are modulated (modified) through their propagation in the heliosphere by the effect of the large scale structure of the interplanetary medium. A wavy structured neutralcurrentsheet(NCS) separatesthe heliosphereintotwo regions of opposite magnetic polarity. During positive magnetic phase, the interplanetary magnetic field (IMF) is directed away from the Sun above the NCS and toward the Sun south of it. During negative magnetic phase the IMF direction is reversed. The angle between the Sun's equatorial plane and the NCS is referred as the tilt angle R, of the neutral sheet. It exhibits a solar activity dependence, R is small near sunspot minimum and large near solar maximum. The 27-day variations of galactic cosmic rays have been related to the changing position of the interplanetary NCS (Swinson and Yasue, 1992; Valdes-Galicia and Dorman, 1997). Here we examine the effect of the interplanetary parameters upon the 27-day variation of galactic cosmic rays during the last three solar cycles. 2. Solar Cycle Dependance We used hourly averaged cosmic ray counts observed with neutron monitors at Deep River (DR) and Huancayo (HU) and muon surface telescope at Nagoya (NA

  18. Series-Produced Helium II Cryostats for the Lhc Magnets: Technical Choices, Industrialisation, Costs

    NASA Astrophysics Data System (ADS)

    Poncet, A.; Parma, V.

    2008-03-01

    Assembled in 8 continuous segments of approximately 2.7 km length each, the He II cryostats for the 1232 cryodipoles and 474 Short Straight Sections (SSS housing the quadrupoles) must fulfill tight technical requirements. They have been produced by industry in large series according to cost-effective industrial production methods to keep expenditure within the financial constraints of the project and assembled under contract at CERN. The specific technical requirements of the generic systems of the cryostat (vacuum, cryogenic, electrical distribution, magnet alignment) are briefly recalled, as well as the basic design choices leading to the definition of their components (vacuum vessels, thermal shielding, supporting systems). Early in the design process emphasis was placed on the feasibility of manufacturing techniques adequate for large series production of components, optimal tooling for time-effective assembly methods, and reliable quality assurance systems. An analytical review of the costs of the cryostats from component procurement to final assembly, tests and interconnection in the machine is presented and compared with initial estimates, together with an appraisal of the results and lessons learned.

  19. Low-energy ion distribution functions on a magnetically quiet day at geostationary altitude /L = 7/

    NASA Technical Reports Server (NTRS)

    Singh, N.; Raitt, W. J.; Yasuhara, F.

    1982-01-01

    Ion energy and pitch angle distribution functions are examined for a magnetically quiet day using averaged data from ATS 6. For both field-aligned and perpendicular fluxes, the populations have a mixture of characteristic energies, and the distribution functions can be fairly well approximated by Maxwellian distributions over three different energy bands in the range 3-600 eV. Pitch angle distributions varying with local time, and energy distributions are used to compute total ion density. Pitch angle scattering mechanisms responsible for the observed transformation of pitch angle distribution are examined, and it is found that a magnetic noise of a certain power spectral density belonging to the electromagnetic ion cyclotron mode near the ion cyclotron frequency can be effective in trapping the field aligned fluxes by pitch angle scattering.

  20. Magnetic Resonance Imaging (MRI) of skeletal muscles in astronauts after 9 days of space flight

    NASA Technical Reports Server (NTRS)

    Jaweed, M.; Narayana, P.; Slopis, J.; Butler, I.; Schneider, V.; Leblanc, A.; Fotedar, L.; Bacon, D.

    1992-01-01

    Skylab data indicated that prolonged exposure of human subjects to microgravity environment causes significant muscle atrophy accompanied by reduced muscle strength and fatigue resistance. The objective of this study was to determine decrements in muscle size, if any, in the soleus and gastrocnemius muscles of male and female astronauts after 9 days of space flight. Methods: Eight astronauts, one female and seven male, between the ages of 31 and 59 years 59-84 kg in body weight were examined by MRI 2-3 times preflight within 16 days before launch, and 2 days, (n=6) and seven days (n=3) after landing. The right leg muscles (gastroc-soleus) were imaged with a lower extremity coil in magnets operating at 1.0 or 1.5 Tsela. The imaging protocol consisted of spin echo with a Tr of 0.70 - 1.5 sec. Thirty to forty 3-5 mm thick slices were acquired in 256 x 128 or 256 x 256 matrices. Acquisition time lasted 20-40 minutes. Multiple slices were measured by computerized planimetry. Results: Compared to the preflight, the cross-sectoral areas (CSA) of the soleus, gastrocnemius, and the leg, at 2 days after landing were reduced (at least p less than 0.05) 8.9 percent, 13.2 percent, and 9.5 percent respectively. The soleus and the leg of three astronauts evaluated at 7 days postflight did not show full recovery compared to the preflight values. Conclusions: It is concluded that l9-days of space flight may cause significant decreases in CSA of the leg muscles. The factors responsible for this loss need further determination.

  1. Tracking of magnetic flux concentrations over a five-day observation, and an insight into surface magnetic flux transport

    NASA Astrophysics Data System (ADS)

    Iida, Yusuke

    2016-06-01

    The solar dynamo problem is the question of how the cyclic variation in the solar magnetic field is maintained. One of the important processes is the transport of magnetic flux by surface convection. To reveal this process, the dependence of the squared displacement of magnetic flux concentrations on the elapsed time is investigated in this paper via a feature-recognition technique and a continual five-day magnetogram. This represents the longest time scale over which a satellite observation has ever been performed for this problem. The dependence is found to follow a power law and differ significantly from that of diffusion transport. Furthermore, there is a change in the behavior at a spatial scale of 103.8 km. A super-diffusion behavior with an index of 1.4 is found at smaller scales, while changing to a sub-diffusion behavior with an index of 0.6 on larger ones. We interpret this difference in the transport regime as coming from the network-flow pattern.

  2. Multiple spacecraft flux rope modeling of the Bastille Day magnetic cloud

    NASA Astrophysics Data System (ADS)

    Mulligan, T.; Russell, C. T.; Anderson, B. J.; Acuna, M. H.

    The Bastille Day magnetic cloud in July 2000 occurred with NEAR in conjunction with the Earth at a radial distance of 1.76 AU and 1.9° from the Earth-Sun line. Propagation time from ACE at 0.99 AU to NEAR indicates the cloud did not decelerate significantly between the Earth and 1.76 AU. Using a non-force-free, kinematic flux rope model we find the rope contained 130 TWb of magnetic flux, was oriented with clock and cone angles of 50° and 83°, and had a radius of 0.25 AU at ACE. At NEAR its radius had expanded to 0.43 AU. Simultaneous modeling of ACE and NEAR data indicate the axial and poloidal magnetic fields vary as R-1.4 and R-1.2 where R is heliocentric distance. Magnetosheath thicknesses of 0.14 AU and 0.23 AU indicate the rope cross section is elongated normal to the cloud axis and the radial direction.

  3. Upgrade of the gas flow control system of the resistive current leads of the LHC inner triplet magnets: Simulation and experimental validation

    SciTech Connect

    Perin, A.; Casas-Cubillos, J.; Pezzetti, M.; Almeida, M.

    2014-01-29

    The 600 A and 120 A circuits of the inner triplet magnets of the Large Hadron Collider are powered by resistive gas cooled current leads. The current solution for controlling the gas flow of these leads has shown severe operability limitations. In order to allow a more precise and more reliable control of the cooling gas flow, new flowmeters will be installed during the first long shutdown of the LHC. Because of the high level of radiation in the area next to the current leads, the flowmeters will be installed in shielded areas located up to 50 m away from the current leads. The control valves being located next to the current leads, this configuration leads to long piping between the valves and the flowmeters. In order to determine its dynamic behaviour, the proposed system was simulated with a numerical model and validated with experimental measurements performed on a dedicated test bench.

  4. LHC Computing

    SciTech Connect

    Lincoln, Don

    2015-07-28

    The LHC is the world’s highest energy particle accelerator and scientists use it to record an unprecedented amount of data. This data is recorded in electronic format and it requires an enormous computational infrastructure to convert the raw data into conclusions about the fundamental rules that govern matter. In this video, Fermilab’s Dr. Don Lincoln gives us a sense of just how much data is involved and the incredible computer resources that makes it all possible.

  5. The history of the LHC

    SciTech Connect

    2010-05-11

    Abstract: From the civil engineering, to the manufacturing of the various magnet types, each building block of this extraordinary machine required ambitious leaps in innovation. This lecture will review the history of the LHC project, focusing on the many challenges -- scientific, technological, managerial -- that had to be met during the various phases of R&D;, industrialization, construction, installation and commissioning.

  6. The history of the LHC

    ScienceCinema

    None

    2011-10-06

    Abstract: From the civil engineering, to the manufacturing of the various magnet types, each building block of this extraordinary machine required ambitious leaps in innovation. This lecture will review the history of the LHC project, focusing on the many challenges -- scientific, technological, managerial -- that had to be met during the various phases of R&D;, industrialization, construction, installation and commissioning.

  7. LHC Nobel Symposium Proceedings

    NASA Astrophysics Data System (ADS)

    Ekelöf, Tord

    2013-12-01

    puzzlement. The apparent absence of hints in the LHC experimental data of new phenomena that could relate to dark matter, dark energy, the dominance of matter over antimatter in the Universe, the unification of the strong and the electroweak interactions and their further unification with gravity left the Symposium with no guidance as to how to answer the question: what next? And in experimental fundamental science it is not the confirmation of already established theories that thrills the most; it is the appearance of the unexpected that creates the greatest excitement. However, the LHC is only at the beginning of its voyage into the uncharted territories of higher energies and smaller dimensions that it was built for, so the possibilities for unexpected discoveries are only starting to be explored. The LHC will start up again in 2015 with nearly twice its previous energy and with increased luminosity—new discoveries might then appear sooner than we even dare hope for! The LHC Nobel Symposium was attended by about 60 invited participants and lasted four days. The program was divided into seven sessions; QCD and Heavy Ion Physics, B Physics, Electroweak Physics, The Higgs Boson, Connections to Neutrino Physics and Astroparticle Physics, Beyond the Standard Model and Forward Look. There were 27 plenary invited talks given by participants, each followed by lively discussions. All but one of the speakers have submitted write-ups of their talks for these proceedings. We are hopeful that the remaining talk will be published in a forthcoming issue of Physica Scripta . I am gratified that Professor Roland Allen has agreed to write a paper on the essence of the Higgs boson discovery to be published in Physica Scripta , intended for undergraduate students and educated physicists, regardless of their field of research. I wish to express my deep gratitude to all Speakers and Participants in the Symposium, to the Members of the Local and International Organizing Committees, to the

  8. LHC detector upgrades

    SciTech Connect

    Dan Green

    2003-09-15

    The LHC detectors are well into their construction phase. The LHC schedule shows first beam to ATLAS and CMS in 2007. Because the LHC accelerator has begun to plan for a ten fold increase in LHC design luminosity (the SLHC or super LHC) it is none too soon to begin to think about the upgrades which will be required of the present LHC detectors. In particular, the tracking systems of ATLAS and CMS will need to be completely rebuilt. Given the time needed to do the R & D, make prototypes, and construct the new detectors and given the accelerator schedule for the SLHC, work needs to begin rather soon.

  9. Overview of LHC physics results at ICHEP

    ScienceCinema

    None

    2011-04-25

     This month LHC physics day will review the physics results presented by the LHC experiments at the 2010 ICHEP in Paris. The experimental presentations will be preceeded by the bi-weekly LHC accelerator status report.The meeting will be broadcast via EVO (detailed info will appear at the time of the meeting in the "Video Services" item on the left menu bar)For those attending, information on accommodation, access to CERN and laptop registration is available from http://cern.ch/lpcc/visits

  10. Overview of LHC physics results at ICHEP

    SciTech Connect

    2011-02-25

     This month LHC physics day will review the physics results presented by the LHC experiments at the 2010 ICHEP in Paris. The experimental presentations will be preceeded by the bi-weekly LHC accelerator status report.The meeting will be broadcast via EVO (detailed info will appear at the time of the meeting in the "Video Services" item on the left menu bar)For those attending, information on accommodation, access to CERN and laptop registration is available from http://cern.ch/lpcc/visits

  11. The seasonal and solar cycle variations of electron density gradient scale length during magnetically disturbed days: implications for Spread F

    NASA Astrophysics Data System (ADS)

    Manju, G.; Devasia, C. V.; Ravindran, S.

    2009-07-01

    The behaviour of electron density gradient scale length, L, around post-sunset hours during the magnetically disturbed days of the summer, winter and equinox seasons of solar maximum (2002) and minimum years (1995) has been studied, using ionosonde data of Trivandrum (8.5°N, 76.5°E, dip = 0.5°N) in the Indian longitude sector. The results indicate a clear seasonal and solar cycle variation in L. Seasonal variations of the maximum vertical drift of the F layer were also examined on these days. In particular, the seasonal variation of the Equatorial Spread F (ESF) during this period is examined in terms of the relative roles of L and the vertical drift of the F layer in the triggering of the collisional Rayleigh-Taylor instability. Our results on the clear-cut seasonal and solar cycle variation in L for disturbed days and its control of ESF occurrence are presented and discussed.

  12. LHC Nobel Symposium Proceedings

    NASA Astrophysics Data System (ADS)

    Ekelöf, Tord

    2013-12-01

    puzzlement. The apparent absence of hints in the LHC experimental data of new phenomena that could relate to dark matter, dark energy, the dominance of matter over antimatter in the Universe, the unification of the strong and the electroweak interactions and their further unification with gravity left the Symposium with no guidance as to how to answer the question: what next? And in experimental fundamental science it is not the confirmation of already established theories that thrills the most; it is the appearance of the unexpected that creates the greatest excitement. However, the LHC is only at the beginning of its voyage into the uncharted territories of higher energies and smaller dimensions that it was built for, so the possibilities for unexpected discoveries are only starting to be explored. The LHC will start up again in 2015 with nearly twice its previous energy and with increased luminosity—new discoveries might then appear sooner than we even dare hope for! The LHC Nobel Symposium was attended by about 60 invited participants and lasted four days. The program was divided into seven sessions; QCD and Heavy Ion Physics, B Physics, Electroweak Physics, The Higgs Boson, Connections to Neutrino Physics and Astroparticle Physics, Beyond the Standard Model and Forward Look. There were 27 plenary invited talks given by participants, each followed by lively discussions. All but one of the speakers have submitted write-ups of their talks for these proceedings. We are hopeful that the remaining talk will be published in a forthcoming issue of Physica Scripta . I am gratified that Professor Roland Allen has agreed to write a paper on the essence of the Higgs boson discovery to be published in Physica Scripta , intended for undergraduate students and educated physicists, regardless of their field of research. I wish to express my deep gratitude to all Speakers and Participants in the Symposium, to the Members of the Local and International Organizing Committees, to the

  13. Specific increases within global decreases: a functional magnetic resonance imaging investigation of five days of motor sequence learning.

    PubMed

    Steele, Christopher J; Penhune, Virginia B

    2010-06-16

    Our capacity to learn movement sequences is fundamental to our ability to interact with the environment. Although different brain networks have been linked with different stages of learning, there is little evidence for how these networks change across learning. We used functional magnetic resonance imaging to identify the specific contributions of the cerebellum and primary motor cortex (M1) during early learning, consolidation, and retention of a motor sequence task. Performance was separated into two components: accuracy (the more explicit, rapidly learned, stimulus-response association component) and synchronization (the more procedural, slowly learned component). The network of brain regions active during early learning was dominated by the cerebellum, premotor cortex, basal ganglia, presupplementary motor area, and supplementary motor area as predicted by existing models. Across days of learning, as performance improved, global decreases were found in the majority of these regions. Importantly, within the context of these global decreases, we found specific regions of the left M1 and right cerebellar VIIIA/VIIB that were positively correlated with improvements in synchronization performance. Improvements in accuracy were correlated with increases in hippocampus, BA 9/10, and the putamen. Thus, the two behavioral measures, accuracy and synchrony, were found to be related to two different sets of brain regions-suggesting that these networks optimize different components of learning. In addition, M1 activity early on day 1 was shown to be predictive of the degree of consolidation on day 2. Finally, functional connectivity between M1 and cerebellum in late learning points to their interaction as a mechanism underlying the long-term representation and expression of a well learned skill. PMID:20554884

  14. Introduction to the HL-LHC Project

    NASA Astrophysics Data System (ADS)

    Rossi, L.; Brüning, O.

    The Large Hadron Collider (LHC) is one of largest scientific instruments ever built. It has been exploring the new energy frontier since 2010, gathering a global user community of 7,000 scientists. To extend its discovery potential, the LHC will need a major upgrade in the 2020s to increase its luminosity (rate of collisions) by a factor of five beyond its design value and the integrated luminosity by a factor of ten. As a highly complex and optimized machine, such an upgrade of the LHC must be carefully studied and requires about ten years to implement. The novel machine configuration, called High Luminosity LHC (HL-LHC), will rely on a number of key innovative technologies, representing exceptional technological challenges, such as cutting-edge 11-12 tesla superconducting magnets, very compact superconducting cavities for beam rotation with ultra-precise phase control, new technology for beam collimation and 300-meter-long high-power superconducting links with negligible energy dissipation. HL-LHC federates efforts and R&D of a large community in Europe, in the US and in Japan, which will facilitate the implementation of the construction phase as a global project.

  15. Tevatron operational status and possible lessons for the LHC

    SciTech Connect

    Lebedev, V.; /Fermilab

    2006-06-01

    This paper provides an overview of the Tevatron Run II luminosity progress and plans, including SC magnet measurements and modeling of field errors in view of the LHC operation. It also discusses antiproton production, stacking and cooling.

  16. Review of the safety of LHC collisions

    NASA Astrophysics Data System (ADS)

    Ellis, John; Giudice, Gian; Mangano, Michelangelo; Tkachev, Igor; Wiedemann, Urs; LHC Safety Assessment Group

    2008-11-01

    The safety of collisions at the Large Hadron Collider (LHC) was studied in 2003 by the LHC Safety Study Group, who concluded that they presented no danger. Here we review their 2003 analysis in light of additional experimental results and theoretical understanding, which enable us to confirm, update and extend the conclusions of the LHC Safety Study Group. The LHC reproduces in the laboratory, under controlled conditions, collisions at centre-of-mass energies, less than those reached in the atmosphere by some of the cosmic rays that have been bombarding the Earth for billions of years. We recall the rates for the collisions of cosmic rays with the Earth, Sun, neutron stars, white dwarfs and other astronomical bodies at energies higher than the LHC. The stability of astronomical bodies indicates that such collisions cannot be dangerous. Specifically, we study the possible production at the LHC of hypothetical objects such as vacuum bubbles, magnetic monopoles, microscopic black holes and strangelets, and find no associated risks. Any microscopic black holes produced at the LHC are expected to decay by Hawking radiation before they reach the detector walls. If some microscopic black holes were stable, those produced by cosmic rays would be stopped inside the Earth or other astronomical bodies. The stability of astronomical bodies strongly constrains the possible rate of accretion by any such microscopic black holes, so that they present no conceivable danger. In the case of strangelets, the good agreement of measurements of particle production at RHIC with simple thermodynamic models severely constrains the production of strangelets in heavy-ion collisions at the LHC, which also present no danger.

  17. Commissioning of the cryogenics of the LHC long straight sections

    SciTech Connect

    Perin, A.; Casas-Cubillos, J.; Claudet, S.; Darve, C.; Ferlin, G.; Millet, F.; Parente, C.; Rabehl, R.; Soubiran, M.; van Weelderen, R.; Wagner, U.; /CERN

    2010-01-01

    The LHC is made of eight circular arcs interspaced with eight Long Straight Sections (LSS). Most powering interfaces to the LHC are located in these sections where the particle beams are focused and shaped for collision, cleaning and acceleration. The LSSs are constituted of several unique cryogenic devices and systems like electrical feed-boxes, standalone superconducting magnets, superconducting links, RF cavities and final focusing superconducting magnets. This paper presents the cryogenic commissioning and the main results obtained during the first operation of the LHC Long Straight Sections.

  18. Impact of time-of-day on brain morphometric measures derived from T1-weighted magnetic resonance imaging.

    PubMed

    Trefler, Aaron; Sadeghi, Neda; Thomas, Adam G; Pierpaoli, Carlo; Baker, Chris I; Thomas, Cibu

    2016-06-01

    Measures of brain morphometry derived from T1-weighted (T1W) magnetic resonance imaging (MRI) are widely used to elucidate the relation between brain structure and function. However, the computation of T1W morphometric measures can be confounded by subject-related factors such as head motion and level of hydration. A recent study reported subtle yet significant changes in brain volume from morning to evening in a large group of patient populations as well as in healthy elderly individuals. In addition, there is a growing recognition that factors such as circadian rhythm can impact MRI measures of brain function and structure. Here, we provide a comprehensive assessment of the impact of time-of-day (TOD) on widely used measures of brain morphometry in a group of 19 healthy young adults. Our results show that (a) even in a small group of healthy adult volunteers, a highly significant reduction in apparent brain volume, from morning to evening, could be detected; (b) the apparent volume of all three major tissue compartments - gray matter, white matter, and cerebrospinal fluid - were influenced by TOD, and the magnitude of the TOD effect varied across the tissue compartments; (c) measures of cortical thickness, cortical surface area, and gray matter density computed with widely used neuroimaging software suites (i.e., FreeSurfer, FSL-VBM) were all affected by TOD, while other measures, such as curvature indices and sulcal depth, were not; and (d) the effect of TOD appeared to have a greater impact on morphometric measures of the frontal and temporal lobe than on other major lobes of the brain. Our results suggest that the TOD effect is a physiological phenomenon and that controlling for the effect of TOD is crucial for proper interpretation of apparent structural differences measured with T1W morphometry. PMID:26921714

  19. Low-Frequency Repetitive Transcranial Magnetic Stimulation and Intensive Occupational Therapy for Poststroke Patients with Upper Limb Hemiparesis: Preliminary Study of a 15-Day Protocol

    ERIC Educational Resources Information Center

    Kakuda, Wataru; Abo, Masahiro; Kobayashi, Kazushige; Momosaki, Ryo; Yokoi, Aki; Fukuda, Akiko; Ishikawa, Atsushi; Ito, Hiroshi; Tominaga, Ayumi

    2010-01-01

    The purpose of the study was to determine the safety and feasibility of a 15-day protocol of low-frequency repetitive transcranial magnetic stimulation (rTMS) combined with intensive occupational therapy (OT) on motor function and spasticity in hemiparetic upper limbs in poststroke patients. Fifteen poststroke patients (age at study entry 55 [plus…

  20. Supersymmetry At LHC

    SciTech Connect

    Khalil, Shaaban

    2008-04-21

    One of the main motivation of the experiments at the Large Hadron Collider (LHC), scheduled to start around 2006, is to search for supersymmetric particles. The region of the parameter space of the minimal supersymmetric standard model, where supersymmetry can be discovered is investigated. We show that if supersymmetry exists at electroweak scale, it would be easy to find signals for it at the LHC. If the LHC does find supersymmetry, this would be one of the greatest achievements in the history of theoretical physics.

  1. News Conference: ASE '09 invigorates participants 34th Stirling Physics Meeting: IOP in Scotland meets to debate curriculum and celebrate success From the News to the Classroom: A positive outlook for science as Obama takes up US presidency Workshop: Nanoschool educates Finnish teachers CERN: Act fast: High School Teacher Programme calls for applicants London Physics Teachers' Network: Teachers' Network Day has an international flavour CERN: LHC timetabled to restart in the summer

    NASA Astrophysics Data System (ADS)

    2009-03-01

    Conference: ASE '09 invigorates participants 34th Stirling Physics Meeting: IOP in Scotland meets to debate curriculum and celebrate success From the News to the Classroom: A positive outlook for science as Obama takes up US presidency Workshop: Nanoschool educates Finnish teachers CERN: Act fast: High School Teacher Programme calls for applicants London Physics Teachers' Network: Teachers' Network Day has an international flavour CERN: LHC timetabled to restart in the summer

  2. The LHC Experiments

    SciTech Connect

    Lincoln, Don

    2015-03-11

    The Large Hadron Collider or LHC is the world’s biggest particle accelerator, but it can only get particles moving very quickly. To make measurements, scientists must employ particle detectors. There are four big detectors at the LHC: ALICE, ATLAS, CMS, and LHCb. In this video, Fermilab’s Dr. Don Lincoln introduces us to these detectors and gives us an idea of each one’s capabilities.

  3. Day to Day

    ERIC Educational Resources Information Center

    Jurecki, Dennis

    2006-01-01

    A clean, healthy and safe school provides students, faculty and staff with an environment conducive to learning and working. However, budget and staff reductions can lead to substandard cleaning practices and unsanitary conditions. Some school facility managers have been making the switch to a day-schedule to reduce security and energy costs, and…

  4. Commissioning the cryogenic system of the first LHC sector

    SciTech Connect

    Millet, F.; Claudet, S.; Ferlin, G.; Perin, A.; Riddone, G.; Serio, L.; Soubiran, M.; Tavian, L.; Ronayette, L.; Rabehl, R.; /Fermilab

    2007-12-01

    The LHC machine, composed of eight sectors with superconducting magnets and accelerating cavities, requires a complex cryogenic system providing high cooling capacities (18 kW equivalent at 4.5 K and 2.4 W at 1.8 K per sector produced in large cold boxes and distributed via 3.3-km cryogenic transfer lines). After individual reception tests of the cryogenic subsystems (cryogen storages, refrigerators, cryogenic transfer lines and distribution boxes) performed since 2000, the commissioning of the cryogenic system of the first LHC sector has been under way since November 2006. After a brief introduction to the LHC cryogenic system and its specificities, the commissioning is reported detailing the preparation phase (pressure and leak tests, circuit conditioning and flushing), the cool-down sequences including the handling of cryogenic fluids, the magnet powering phase and finally the warm-up. Preliminary conclusions on the commissioning of the first LHC sector will be drawn with the review of the critical points already solved or still pending. The last part of the paper reports on the first operational experience of the LHC cryogenic system in the perspective of the commissioning of the remaining LHC sectors and the beam injection test.

  5. Run II of the LHC: The Accelerator Science

    NASA Astrophysics Data System (ADS)

    Redaelli, Stefano

    2015-04-01

    In 2015 the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) starts its Run II operation. After the successful Run I at 3.5 TeV and 4 TeV in the 2010-2013 period, a first long shutdown (LS1) was mainly dedicated to the consolidation of the LHC magnet interconnections, to allow the LHC to operate at its design beam energy of 7 TeV. Other key accelerator systems have also been improved to optimize the performance reach at higher beam energies. After a review of the LS1 activities, the status of the LHC start-up progress is reported, addressing in particular the status of the LHC hardware commissioning and of the training campaign of superconducting magnets that will determine the operation beam energy in 2015. Then, the plans for the Run II operation are reviewed in detail, covering choice of initial machine parameters and strategy to improve the Run II performance. Future prospects of the LHC and its upgrade plans are also presented.

  6. Beam Loss Monitoring for LHC Machine Protection

    NASA Astrophysics Data System (ADS)

    Holzer, Eva Barbara; Dehning, Bernd; Effnger, Ewald; Emery, Jonathan; Grishin, Viatcheslav; Hajdu, Csaba; Jackson, Stephen; Kurfuerst, Christoph; Marsili, Aurelien; Misiowiec, Marek; Nagel, Markus; Busto, Eduardo Nebot Del; Nordt, Annika; Roderick, Chris; Sapinski, Mariusz; Zamantzas, Christos

    The energy stored in the nominal LHC beams is two times 362 MJ, 100 times the energy of the Tevatron. As little as 1 mJ/cm3 deposited energy quenches a magnet at 7 TeV and 1 J/cm3 causes magnet damage. The beam dumps are the only places to safely dispose of this beam. One of the key systems for machine protection is the beam loss monitoring (BLM) system. About 3600 ionization chambers are installed at likely or critical loss locations around the LHC ring. The losses are integrated in 12 time intervals ranging from 40 μs to 84 s and compared to threshold values defined in 32 energy ranges. A beam abort is requested when potentially dangerous losses are detected or when any of the numerous internal system validation tests fails. In addition, loss data are used for machine set-up and operational verifications. The collimation system for example uses the loss data for set-up and regular performance verification. Commissioning and operational experience of the BLM are presented: The machine protection functionality of the BLM system has been fully reliable; the LHC availability has not been compromised by false beam aborts.

  7. Regularly scheduled, day-time, slow-onset 60 Hz electric and magnetic field exposure does not depress serum melatonin concentration in nonhuman primates

    SciTech Connect

    Rogers, W.R.; Smith, H.D.; Orr, J.L.; Reiter, R.J.; Barlow-Walden, L.

    1995-12-31

    Experiments conducted with laboratory rodents indicate that exposure to 60 Hz electric fields or magnetic fields can suppress nocturnal melatonin concentrations in pineal gland and blood. In three experiments employing three field-exposed and three sham-exposed nonhuman primates, each implanted with an indwelling venous cannula to allow repeated blood sampling, the authors studied the effects of either 6 kV/m and 50 {micro}T (0.5 G) or 30 kV/m and 100 {micro}T (1.0 G) on serum melatonin patterns. The fields were ramped on and off slowly, so that no transients occurred. Extensive quality control for the melatonin assay, computerized control and monitoring of field intensities, and consistent exposure protocols were used. No changes in nocturnal serum melatonin concentration resulted from 6 weeks of day-time exposure with slow field onset/offset and a highly regular exposure protocol. These results indicate that, under the conditions tested, day-time exposure to 60 Hz electric and magnetic fields in combination does not result in melatonin suppression in primates.

  8. LHC forward physics

    SciTech Connect

    Cartiglia, N.; Royon, C.

    2015-10-02

    The goal of this report is to give a comprehensive overview of the rich field of forward physics, with a special attention to the topics that can be studied at the LHC. The report starts presenting a selection of the Monte Carlo simulation tools currently available, chapter 2, then enters the rich phenomenology of QCD at low, chapter 3, and high, chapter 4, momentum transfer, while the unique scattering conditions of central exclusive production are analyzed in chapter 5. The last two experimental topics, Cosmic Ray and Heavy Ion physics are presented in the chapter 6 and 7 respectively. Chapter 8 is dedicated to the BFKL dynamics, multiparton interactions, and saturation. The report ends with an overview of the forward detectors at LHC. Each chapter is correlated with a comprehensive bibliography, attempting to provide to the interested reader with a wide opportunity for further studies.

  9. The ALICE experiment at the CERN LHC

    NASA Astrophysics Data System (ADS)

    ALICE Collaboration; Aamodt, K.; Abrahantes Quintana, A.; Achenbach, R.; Acounis, S.; Adamová, D.; Adler, C.; Aggarwal, M.; Agnese, F.; Aglieri Rinella, G.; Ahammed, Z.; Ahmad, A.; Ahmad, N.; Ahmad, S.; Akindinov, A.; Akishin, P.; Aleksandrov, D.; Alessandro, B.; Alfaro, R.; Alfarone, G.; Alici, A.; Alme, J.; Alt, T.; Altinpinar, S.; Amend, W.; Andrei, C.; Andres, Y.; Andronic, A.; Anelli, G.; Anfreville, M.; Angelov, V.; Anzo, A.; Anson, C.; Anticić, T.; Antonenko, V.; Antonczyk, D.; Antinori, F.; Antinori, S.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Aprodu, V.; Arba, M.; Arcelli, S.; Argentieri, A.; Armesto, N.; Arnaldi, R.; Arefiev, A.; Arsene, I.; Asryan, A.; Augustinus, A.; Awes, T. C.; Äysto, J.; Danish Azmi, M.; Bablock, S.; Badalà, A.; Badyal, S. K.; Baechler, J.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baldit, A.; Bán, J.; Barbera, R.; Barberis, P.-L.; Barbet, J. M.; Barnäfoldi, G.; Barret, V.; Bartke, J.; Bartos, D.; Basile, M.; Basmanov, V.; Bastid, N.; Batigne, G.; Batyunya, B.; Baudot, J.; Baumann, C.; Bearden, I.; Becker, B.; Belikov, J.; Bellwied, R.; Belmont-Moreno, E.; Belogianni, A.; Belyaev, S.; Benato, A.; Beney, J. L.; Benhabib, L.; Benotto, F.; Beolé, S.; Berceanu, I.; Bercuci, A.; Berdermann, E.; Berdnikov, Y.; Bernard, C.; Berny, R.; Berst, J. D.; Bertelsen, H.; Betev, L.; Bhasin, A.; Baskar, P.; Bhati, A.; Bianchi, N.; Bielčik, J.; Bielčiková, J.; Bimbot, L.; Blanchard, G.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Blyth, S.; Boccioli, M.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Bombonati, C.; Bondila, M.; Bonnet, D.; Bonvicini, V.; Borel, H.; Borotto, F.; Borshchov, V.; Bortoli, Y.; Borysov, O.; Bose, S.; Bosisio, L.; Botje, M.; Böttger, S.; Bourdaud, G.; Bourrion, O.; Bouvier, S.; Braem, A.; Braun, M.; Braun-Munzinger, P.; Bravina, L.; Bregant, M.; Bruckner, G.; Brun, R.; Bruna, E.; Brunasso, O.; Bruno, G. E.; Bucher, D.; Budilov, V.; Budnikov, D.; Buesching, H.; Buncic, P.; Burns, M.; Burachas, S.; Busch, O.; Bushop, J.; Cai, X.; Caines, H.; Calaon, F.; Caldogno, M.; Cali, I.; Camerini, P.; Campagnolo, R.; Campbell, M.; Cao, X.; Capitani, G. P.; Romeo, G. Cara; Cardenas-Montes, M.; Carduner, H.; Carena, F.; Carena, W.; Cariola, P.; Carminati, F.; Casado, J.; Casanova Diaz, A.; Caselle, M.; Castillo Castellanos, J.; Castor, J.; Catanescu, V.; Cattaruzza, E.; Cavazza, D.; Cerello, P.; Ceresa, S.; Černý, V.; Chambert, V.; Chapeland, S.; Charpy, A.; Charrier, D.; Chartoire, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chepurnov, V.; Chernenko, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chochula, P.; Chiavassa, E.; Chibante Barroso, V.; Choi, J.; Christakoglou, P.; Christiansen, P.; Christensen, C.; Chykalov, O. A.; Cicalo, C.; Cifarelli-Strolin, L.; Ciobanu, M.; Cindolo, F.; Cirstoiu, C.; Clausse, O.; Cleymans, J.; Cobanoglu, O.; Coffin, J.-P.; Coli, S.; Colla, A.; Colledani, C.; Combaret, C.; Combet, M.; Comets, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Contin, G.; Contreras, J.; Cormier, T.; Corsi, F.; Cortese, P.; Costa, F.; Crescio, E.; Crochet, P.; Cuautle, E.; Cussonneau, J.; Dahlinger, M.; Dainese, A.; Dalsgaard, H. H.; Daniel, L.; Das, I.; Das, T.; Dash, A.; Da Silva, R.; Davenport, M.; Daues, H.; DeCaro, A.; de Cataldo, G.; DeCuveland, J.; DeFalco, A.; de Gaspari, M.; de Girolamo, P.; de Groot, J.; DeGruttola, D.; DeHaas, A.; DeMarco, N.; DePasquale, S.; DeRemigis, P.; de Vaux, D.; Decock, G.; Delagrange, H.; DelFranco, M.; Dellacasa, G.; Dell'Olio, C.; Dell'Olio, D.; Deloff, A.; Demanov, V.; Dénes, E.; D'Erasmo, G.; Derkach, D.; Devaux, A.; Di Bari, D.; Di Bartelomen, A.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Dialinas, M.; Diaz, L.; Díaz Valdes, R.; Dietel, T.; Dima, R.; Ding, H.; Dinca, C.; Divià, R.; Dobretsov, V.; Dobrin, A.; Doenigus, B.; Dobrowolski, T.; Domínguez, I.; Dorn, M.; Drouet, S.; Dubey, A. E.; Ducroux, L.; Dumitrache, F.; Dumonteil, E.; Dupieux, P.; Duta, V.; Dutta Majumdar, A.; Dutta Majumdar, M.; Dyhre, Th; Efimov, L.; Efremov, A.; Elia, D.; Emschermann, D.; Engster, C.; Enokizono, A.; Espagnon, B.; Estienne, M.; Evangelista, A.; Evans, D.; Evrard, S.; Fabjan, C. W.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Farano, R.; Fearick, R.; Fedorov, O.; Fekete, V.; Felea, D.; Feofilov, G.; Férnandez Téllez, A.; Ferretti, A.; Fichera, F.; Filchagin, S.; Filoni, E.; Finck, C.; Fini, R.; Fiore, E. M.; Flierl, D.; Floris, M.; Fodor, Z.; Foka, Y.; Fokin, S.; Force, P.; Formenti, F.; Fragiacomo, E.; Fragkiadakis, M.; Fraissard, D.; Franco, A.; Franco, M.; Frankenfeld, U.; Fratino, U.; Fresneau, S.; Frolov, A.; Fuchs, U.; Fujita, J.; Furget, C.; Furini, M.; Fusco Girard, M.; Gaardhøje, J.-J.; Gabrielli, A.; Gadrat, S.; Gagliardi, M.; Gago, A.; Gaido, L.; Gallas Torreira, A.; Gallio, M.; Gandolfi, E.; Ganoti, P.; Ganti, M.; Garabatos, J.; Garcia Lopez, A.; Garizzo, L.; Gaudichet, L.; Gemme, R.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Giolu, G.; Giraudo, G.; Giubellino, P.; Glasow, R.; Glässel, P.; Ferreiro, E. G.; Gonzalez Gutierrez, C.; Gonzales-Trueba, L. H.; Gorbunov, S.; Gorbunov, Y.; Gos, H.; Gosset, J.; Gotovac, S.; Gottschlag, H.; Gottschalk, D.; Grabski, V.; Grassi, T.; Gray, H.; Grebenyuk, O.; Grebieszkow, K.; Gregory, C.; Grigoras, C.; Grion, N.; Grigoriev, V.; Grigoryan, A.; Grigoryan, C.; Grigoryan, S.; Grishuk, Y.; Gros, P.; Grosse-Oetringhaus, J.; Grossiord, J.-Y.; Grosso, R.; Grynyov, B.; Guarnaccia, C.; Guber, F.; Guerin, F.; Guernane, R.; Guerzoni, M.; Guichard, A.; Guida, M.; Guilloux, G.; Gulkanyan, H.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, V.; Gustafsson, H.-A.; Gutbrod, H.; Hadjidakis, C.; Haiduc, M.; Hamar, G.; Hamagaki, H.; Hamblen, J.; Hansen, J. C.; Hardy, P.; Hatzifotiadou, D.; Harris, J. W.; Hartig, M.; Harutyunyan, A.; Hayrapetyan, A.; Hasch, D.; Hasegan, D.; Hehner, J.; Heine, N.; Heinz, M.; Helstrup, H.; Herghelegiu, A.; Herlant, S.; Herrera Corral, G.; Herrmann, N.; Hetland, K.; Hille, P.; Hinke, H.; Hippolyte, B.; Hoch, M.; Hoebbel, H.; Hoedlmoser, H.; Horaguchi, T.; Horner, M.; Hristov, P.; Hřivnáčová, I.; Hu, S.; Guo, C. Hu; Humanic, T.; Hurtado, A.; Hwang, D. S.; Ianigro, J. C.; Idzik, M.; Igolkin, S.; Ilkaev, R.; Ilkiv, I.; Imhoff, M.; Innocenti, P. G.; Ionescu, E.; Ippolitov, M.; Irfan, M.; Insa, C.; Inuzuka, M.; Ivan, C.; Ivanov, A.; Ivanov, M.; Ivanov, V.; Jacobs, P.; Jacholkowski, A.; Jančurová, L.; Janik, R.; Jasper, M.; Jena, C.; Jirden, L.; Johnson, D. P.; Jones, G. T.; Jorgensen, C.; Jouve, F.; Jovanović, P.; Junique, A.; Jusko, A.; Jung, H.; Jung, W.; Kadija, K.; Kamal, A.; Kamermans, R.; Kapusta, S.; Kaidalov, A.; Kakoyan, V.; Kalcher, S.; Kang, E.; Kapitan, J.; Kaplin, V.; Karadzhev, K.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Karpio, K.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Mohsin Khan, M.; Khanzadeev, A.; Kharlov, Y.; Kikola, D.; Kileng, B.; Kim, D.; Kim, D. S.; Kim, D. W.; Kim, H. N.; Kim, J. S.; Kim, S.; Kinson, J. B.; Kiprich, S. K.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, T.; Kiworra, V.; Klay, J.; Klein Bösing, C.; Kliemant, M.; Klimov, A.; Klovning, A.; Kluge, A.; Kluit, R.; Kniege, S.; Kolevatov, R.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kornas, E.; Koshurnikov, E.; Kotov, I.; Kour, R.; Kowalski, M.; Kox, S.; Kozlov, K.; Králik, I.; Kramer, F.; Kraus, I.; Kravčáková, A.; Krawutschke, T.; Krivda, M.; Kryshen, E.; Kucheriaev, Y.; Kugler, A.; Kuhn, C.; Kuijer, P.; Kumar, L.; Kumar, N.; Kumpumaeki, P.; Kurepin, A.; Kurepin, A. N.; Kushpil, S.; Kushpil, V.; Kutovsky, M.; Kvaerno, H.; Kweon, M.; Labbé, J.-C.; Lackner, F.; Ladron de Guevara, P.; Lafage, V.; La Rocca, P.; Lamont, M.; Lara, C.; Larsen, D. T.; Laurenti, G.; Lazzeroni, C.; LeBornec, Y.; LeBris, N.; LeGailliard, C.; Lebedev, V.; Lecoq, J.; Lee, K. S.; Lee, S. C.; Lefévre, F.; Legrand, I.; Lehmann, T.; Leistam, L.; Lenoir, P.; Lenti, V.; Leon, H.; Monzon, I. Leon; Lévai, P.; Li, Q.; Li, X.; Librizzi, F.; Lietava, R.; Lindegaard, N.; Lindenstruth, V.; Lippmann, C.; Lisa, M.; Listratenko, O. M.; Littel, F.; Liu, Y.; Lo, J.; Lobanov, V.; Loginov, V.; López Noriega, M.; López-Ramírez, R.; López Torres, E.; Lorenzo, P. M.; Løvhøiden, G.; Lu, S.; Ludolphs, W.; Lunardon, M.; Luquin, L.; Lusso, S.; Lutz, J.-R.; Luvisetto, M.; Lyapin, V.; Maevskaya, A.; Magureanu, C.; Mahajan, A.; Majahan, S.; Mahmoud, T.; Mairani, A.; Mahapatra, D.; Makarov, A.; Makhlyueva, I.; Malek, M.; Malkiewicz, T.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manea, C.; Mangotra, L. K.; Maniero, D.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marcel, A.; Marchini, S.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marin, A.; Marin, J.-C.; Marras, D.; Martinengo, P.; Martínez, M. I.; Martinez-Davalos, A.; Martínez Garcia, G.; Martini, S.; Marzari Chiesa, A.; Marzocca, C.; Masciocchi, S.; Masera, M.; Masetti, M.; Maslov, N. I.; Masoni, A.; Massera, F.; Mast, M.; Mastroserio, A.; Matthews, Z. L.; Mayer, B.; Mazza, G.; Mazzaro, M. D.; Mazzoni, A.; Meddi, F.; Meleshko, E.; Menchaca-Rocha, A.; Meneghini, S.; Meoni, M.; Mercado Perez, J.; Mereu, P.; Meunier, O.; Miake, Y.; Michalon, A.; Michinelli, R.; Miftakhov, N.; Mignone, M.; Mikhailov, K.; Milosevic, J.; Minaev, Y.; Minafra, F.; Mischke, A.; Miśkowiec, D.; Mitsyn, V.; Mitu, C.; Mohanty, B.; Moisa, D.; Molnar, L.; Mondal, M.; Mondal, N.; Montaño Zetina, L.; Monteno, M.; Morando, M.; Morel, M.; Moretto, S.; Morhardt, Th; Morsch, A.; Moukhanova, T.; Mucchi, M.; Muccifora, V.; Mudnic, E.; Müller, H.; Müller, W.; Munoz, J.; Mura, D.; Musa, L.; Muraz, J. F.; Musso, A.; Nania, R.; Nandi, B.; Nappi, E.; Navach, F.; Navin, S.; Nayak, T.; Nazarenko, S.; Nazarov, G.; Nellen, L.; Nendaz, F.; Nianine, A.; Nicassio, M.; Nielsen, B. S.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B.; Nitti, M.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noto, F.; Nouais, D.; Nyiri, A.; Nystrand, J.; Odyniec, G.; Oeschler, H.; Oinonen, M.; Oldenburg, M.; Oleks, I.; Olsen, E. K.; Onuchin, V.; Oppedisano, C.; Orsini, F.; Ortiz-Velázquez, A.; Oskamp, C.; Oskarsson, A.; Osmic, F.; Österman, L.; Otterlund, I.; Ovrebekk, G.; Oyama, K.; Pachr, M.; Pagano, P.; Paić, G.; Pajares, C.; Pal, S.; Pal, S.; Pálla, G.; Palmeri, A.; Pancaldi, G.; Panse, R.; Pantaleo, A.; Pappalardo, G. S.; Pastirčák, B.; Pastore, C.; Patarakin, O.; Paticchio, V.; Patimo, G.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pénichot, Y.; Pepato, A.; Pereira, H.; Peresunko, D.; Perez, C.; Perez Griffo, J.; Perini, D.; Perrino, D.; Peryt, W.; Pesci, A.; Peskov, V.; Pestov, Y.; Peters, A. J.; Petráček, V.; Petridis, A.; Petris, M.; Petrov, V.; Petrov, V.; Petrovici, M.; Peyré, J.; Piano, S.; Piccotti, A.; Pichot, P.; Piemonte, C.; Pikna, M.; Pilastrini, R.; Pillot, P.; Pinazza, O.; Pini, B.; Pinsky, L.; Pinto Morais, V.; Pismennaya, V.; Piuz, F.; Platt, R.; Ploskon, M.; Plumeri, S.; Pluta, J.; Pocheptsov, T.; Podesta, P.; Poggio, F.; Poghosyan, M.; Poghosyan, T.; Polák, K.; Polichtchouk, B.; Polozov, P.; Polyakov, V.; Pommeresch, B.; Pompei, F.; Pop, A.; Popescu, S.; Posa, F.; Pospíšil, V.; Potukuchi, B.; Pouthas, J.; Prasad, S.; Preghenella, R.; Prino, F.; Prodan, L.; Prono, G.; Protsenko, M. A.; Pruneau, C. A.; Przybyla, A.; Pshenichnov, I.; Puddu, G.; Pujahari, P.; Pulvirenti, A.; Punin, A.; Punin, V.; Putschke, J.; Quartieri, J.; Quercigh, E.; Rachevskaya, I.; Rachevski, A.; Rademakers, A.; Radomski, S.; Radu, A.; Rak, J.; Ramello, L.; Raniwala, R.; Raniwala, S.; Rasmussen, O. B.; Rasson, J.; Razin, V.; Read, K.; Real, J.; Redlich, K.; Reichling, C.; Renard, C.; Renault, G.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Revol, J.-P.; Reygers, K.; Ricaud, H.; Riccati, L.; Ricci, R. A.; Richter, M.; Riedler, P.; Rigalleau, L. M.; Riggi, F.; Riegler, W.; Rindel, E.; Riso, J.; Rivetti, A.; Rizzi, M.; Rizzi, V.; Rodriguez Cahuantzi, M.; Røed, K.; Röhrich, D.; Román-López, S.; Romanato, M.; Romita, R.; Ronchetti, F.; Rosinsky, P.; Rosnet, P.; Rossegger, S.; Rossi, A.; Rostchin, V.; Rotondo, F.; Roukoutakis, F.; Rousseau, S.; Roy, C.; Roy, D.; Roy, P.; Royer, L.; Rubin, G.; Rubio, A.; Rui, R.; Rusanov, I.; Russo, G.; Ruuskanen, V.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahoo, R.; Saini, J.; Saiz, P.; Salur, S.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sann, H.; Santiard, J.-C.; Santo, R.; Santoro, R.; Sargsyan, G.; Saturnini, P.; Scapparone, E.; Scarlassara, F.; Schackert, B.; Schiaua, C.; Schicker, R.; Schioler, T.; Schippers, J. D.; Schmidt, C.; Schmidt, H.; Schneider, R.; Schossmaier, K.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Schyns, E.; Scioli, G.; Scomparin, E.; Snow, H.; Sedykh, S.; Segato, G.; Sellitto, S.; Semeria, F.; Senyukov, S.; Seppänen, H.; Serci, S.; Serkin, L.; Serra, S.; Sesselmann, T.; Sevcenco, A.; Sgura, I.; Shabratova, G.; Shahoyan, R.; Sharkov, E.; Sharma, S.; Shigaki, K.; Shileev, K.; Shukla, P.; Shurygin, A.; Shurygina, M.; Sibiriak, Y.; Siddi, E.; Siemiarczuk, T.; Sigward, M. H.; Silenzi, A.; Silvermyr, D.; Silvestri, R.; Simili, E.; Simion, V.; Simon, R.; Simonetti, L.; Singaraju, R.; Singhal, V.; Sinha, B.; Sinha, T.; Siska, M.; Sitár, B.; Sitta, M.; Skaali, B.; Skowronski, P.; Slodkowski, M.; Smirnov, N.; Smykov, L.; Snellings, R.; Snoeys, W.; Soegaard, C.; Soerensen, J.; Sokolov, O.; Soldatov, A.; Soloviev, A.; Soltveit, H.; Soltz, R.; Sommer, W.; Soos, C.; Soramel, F.; Sorensen, S.; Soyk, D.; Spyropoulou-Stassinaki, M.; Stachel, J.; Staley, F.; Stan, I.; Stavinskiy, A.; Steckert, J.; Stefanini, G.; Stefanek, G.; Steinbeck, T.; Stelzer, H.; Stenlund, E.; Stocco, D.; Stockmeier, M.; Stoicea, G.; Stolpovsky, P.; Strmeň, P.; Stutzmann, J. S.; Su, G.; Sugitate, T.; Šumbera, M.; Suire, C.; Susa, T.; Sushil Kumar, K.; Swoboda, D.; Symons, J.; Szarka, I.; Szostak, A.; Szuba, M.; Szymanski, P.; Tadel, M.; Tagridis, C.; Tan, L.; Tapia Takaki, D.; Taureg, H.; Tauro, A.; Tavlet, M.; Tejeda Munoz, G.; Thäder, J.; Tieulent, R.; Timmer, P.; Tolyhy, T.; Topilskaya, N.; Torcato de Matos, C.; Torii, H.; Toscano, L.; Tosello, F.; Tournaire, A.; Traczyk, T.; Tröger, G.; Tromeur, W.; Truesdale, D.; Trzaska, W.; Tsiledakis, G.; Tsilis, E.; Tsvetkov, A.; Turcato, M.; Turrisi, R.; Tuveri, M.; Tveter, T.; Tydesjo, H.; Tykarski, L.; Tywoniuk, K.; Ugolini, E.; Ullaland, K.; Urbán, J.; Urciuoli, G. M.; Usai, G. L.; Usseglio, M.; Vacchi, A.; Vala, M.; Valiev, F.; Vande Vyvre, P.; Van Den Brink, A.; Van Eijndhoven, N.; Van Der Kolk, N.; van Leeuwen, M.; Vannucci, L.; Vanzetto, S.; Vanuxem, J.-P.; Vargas, M. A.; Varma, R.; Vascotto, A.; Vasiliev, A.; Vassiliou, M.; Vasta, P.; Vechernin, V.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Verhoeven, W.; Veronese, F.; Vetlitskiy, I.; Vernet, R.; Victorov, V.; Vidak, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y.; Vodopianov, A.; Volpe, G.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wabnitz, C.; Wagner, V.; Wallet, L.; Wan, R.; Wang, Y.; Wang, Y.; Wheadon, R.; Weis, R.; Wen, Q.; Wessels, J.; Westergaard, J.; Wiechula, J.; Wiesenaecker, A.; Wikne, J.; Wilk, A.; Wilk, G.; Williams, C.; Willis, N.; Windelband, B.; Witt, R.; Woehri, H.; Wyllie, K.; Xu, C.; Yang, C.; Yang, H.; Yermia, F.; Yin, Z.; Yin, Z.; Ky, B. Yun; Yushmanov, I.; Yuting, B.; Zabrodin, E.; Zagato, S.; Zagreev, B.; Zaharia, P.; Zalite, A.; Zampa, G.; Zampolli, C.; Zanevskiy, Y.; Zarochentsev, A.; Zaudtke, O.; Závada, P.; Zbroszczyk, H.; Zepeda, A.; Zeter, V.; Zgura, I.; Zhalov, M.; Zhou, D.; Zhou, S.; Zhu, G.; Zichichi, A.; Zinchenko, A.; Zinovjev, G.; Zoccarato, Y.; Zubarev, A.; Zucchini, A.; Zuffa, M.

    2008-08-01

    ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 16 × 16 × 26 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This

  10. LHC and SPS Electron Cloud Studies

    SciTech Connect

    Jimenez, J.M.; Henrist, B.; Hilleret, N.; Laurent, J.-M.; Schulte, D.; Zimmermann, F.

    2005-06-08

    The additional heat load onto the LHC beam screens of the cold magnets in the bending sections ({approx}21 km) is still considered as one of the main possible limitations of the LHC performances. Since more than three years, the characteristics of the electron cloud are being studied in the SPS at ambient (RT) and cryogenic temperatures in both dipole and field free conditions. The results obtained in the SPS in 2003 showed a vacuum cleaning (or vacuum scrubbing) on both ambient and cryogenic surfaces. On the contrary, the heat load and the electron intensity (current collected at the detector) under both dipole and field free conditions at 4.5 or 30 K had shown only a limited decrease after 12 A.h of beam i.e. beam conditioning. Water contamination coming from the unbaked upstream and downstream parts of the SPS (non-baked machine) was suspected to be responsible for this behavior. The upgrade of the existing detectors as well as the design and results obtained with the new strip detector installed in a quadrupole are presented. Preliminary results on the electron cloud build up in the quadrupole will also be presented and compared to the predictions of the simulations. The effects of the gases physisorbed at cryogenic temperature in the SPS and in the laboratory are shown and the applicability to the LHC will be discussed.

  11. Higgs Boson Search at LHC (and LHC/CMS status)

    SciTech Connect

    Korytov, Andrey

    2008-11-23

    Presented are the results of the most recent studies by the CMS and ATLAS collaborations on the expected sensitivity of their detectors to observing a Higgs boson at LHC. The overview is preceded with a brief summary of the LHC and the CMS Experiment status.

  12. Kindergarten: All Day Every Day?

    ERIC Educational Resources Information Center

    Oelerich, Marjorie L.

    This paper reports findings that all-day every-day educational programs have positive effects on kindergarten children. Also included is a Minnesota Association for Childhood Education (MACE) position paper which advocates the provision of full-day kindergarten programs and details seven criteria that a quality full-day program must meet. Efforts…

  13. LNV Higgses at LHC

    NASA Astrophysics Data System (ADS)

    Maiezza, Alessio; Nemevšek, Miha; Nesti, Fabrizio

    2016-06-01

    Lepton number is a fundamental symmetry that can be probed at the LHC. Here, we study the Higgs sector of theories responsible for neutrino mass generation. After a brief discussion of simple see-saw scenarios, we turn to theories where heavy Majorana neutrino mass is protected by a gauge symmetry and focus on the Left-Right symmetric theory. There, the SM-like Higgs boson can decay to a pair of heavy neutrinos and provide enough information to establish the origin of neutrino mass.

  14. Monotops at the LHC

    SciTech Connect

    Andrea, J.; Fuks, B.

    2011-10-01

    We explore scenarios where top quarks may be produced singly in association with missing energy, a very distinctive signature, which, in analogy with monojets, we dub monotops. We find that monotops can be produced in a variety of modes, typically characterized by baryon number-violating or flavorchanging neutral interactions. We build a simplified model that encompasses all the possible (tree-level) production mechanisms and study the LHC sensitiveness to a few representative scenarios by considering fully hadronic top decays. We find that constraints on such exotic models can already be set with 1 fb{sup -1} of integrated luminosity collected at {radical}(s)=7 TeV.

  15. Dynamic aperture studies for the LHC high luminosity lattice

    SciTech Connect

    Maria, R. de; Giovannozzi, M.; McIntosh, E.; Nosochkov, Y. M.; Cai, Y.; Wang, M. -H.

    2015-07-14

    Since quite some time, dynamic aperture studies have been undertaken with the aim of specifying the required field quality of the new magnets that will be installed in the LHC ring in the framework of the high-luminosity upgrade. In this paper the latest results concerning the specification work will be presented, taking into account both injection and collision energies and the field quality contribution from all the magnets in the newly designed interaction regions.

  16. Supersymmetry at LHC

    SciTech Connect

    Bartl, A.; Soederqvist, J.; Paige, F.

    1996-11-22

    Supersymmetry (SUSY) is an appealing concept which provides a plausible solution to the fine tuning problem, while leaving the phenomenological success of the Standard Model (SM) unchanged. Moreover, some SUSY models allow for the unification of gauge couplings at a scale of M{sub GUT} {approx} 10{sup 16} GeV. A further attractive feature is the possibility of radiative breaking of the electro-weak symmetry group SU(2) {times} U(1). The masses of the SUSY partners of the SM particles are expected to be in the range 100 GeV to 1 TeV. One of the main goals of the Large Hadron Collider (LHC) will be either to discover weak-scale SUSY or to exclude it over the entire theoretically allowed parameter space. The authors have developed a strategy for the analysis of experimental data at LHC which will allow them to determine the scale for supersymmetry, to limit the model parameter space, and to make precision measurements of model parameters.

  17. LHC - a "Why" Facility

    ScienceCinema

    Gordon Kane

    2010-01-08

    The Standard Models of particle physics and cosmology describe the world we see, and how it works, very well. But we want to understand (not just accommodate) much more ? how does the Higgs mechanism work, what is the dark matter, why is the universe matter and not antimatter, why is parity violated, why are the particles (quarks and leptons) what they are, and why are the forces that act on them to make our world what they are, and more. Today is an exciting time to be doing particle physics ? on the experimental side we have data coming from LHC and dark matter experiments that will provide clues to these questions, and on the theoretical side we have a framework (string theory) that addresses all these ?why? questions. LHC data will not qualitatively improve our description ? rather, it may provide the data that will allow us to learn about the dark matter, the Higgs physics, the matter asymmetry, etc, to test underlying theories such as string theory, and begin to answer the ?why? questions. Supersymmetry is the best motivated discovery, and it would also open a window to the underlying theory near the Planck scale.

  18. Dinosaur Day!

    ERIC Educational Resources Information Center

    Nakamura, Sandra; Baptiste, H. Prentice

    2006-01-01

    In this article, the authors describe how they capitalized on their first-grade students' love of dinosaurs by hosting a fun-filled Dinosaur Day in their classroom. On Dinosaur Day, students rotated through four dinosaur-related learning stations that integrated science content with art, language arts, math, and history in a fun and time-efficient…

  19. CEMI Days

    SciTech Connect

    2015-07-01

    CEMI Days are an important channel of engagement between DOE and the manufacturing industry to identify challenges and opportunities for increasing U.S. manufacturing competitiveness. CEMI Days that are held at manufacturing companies’ facilities can include tours of R&D operations or other points of interest determined by the host company.

  20. Day Care.

    ERIC Educational Resources Information Center

    Merro, John; And Others

    Interviews on the quality of day care in the United States are presented in this transcript of a program broadcast in the National Public Radio weekly series, "Options in Education." Writers, day care center personnel and others describe and evaluate the current situation. Federal legislation concerning children is examined, and researchers…

  1. PDF4LHC recommendations for LHC Run II

    NASA Astrophysics Data System (ADS)

    Butterworth, Jon; Carrazza, Stefano; Cooper-Sarkar, Amanda; De Roeck, Albert; Feltesse, Joël; Forte, Stefano; Gao, Jun; Glazov, Sasha; Huston, Joey; Kassabov, Zahari; McNulty, Ronan; Morsch, Andreas; Nadolsky, Pavel; Radescu, Voica; Rojo, Juan; Thorne, Robert

    2016-02-01

    We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+{α }s uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new generation of PDFs, which include substantial information from experimental data from the Run I of the LHC. We then propose a new prescription for the combination of a suitable subset of the available PDF sets, which is presented in terms of a single combined PDF set. We finally discuss tools which allow for the delivery of this combined set in terms of optimized sets of Hessian eigenvectors or Monte Carlo replicas, and their usage, and provide some examples of their application to LHC phenomenology. This paper is dedicated to the memory of Guido Altarelli (1941-2015), whose seminal work made possible the quantitative study of PDFs.

  2. PDF4LHC recommendations for LHC Run II

    DOE PAGESBeta

    Butterworth, Jon; Carrazza, Stefano; Cooper-Sarkar, Amanda; Roeck, Albert De; Feltesse, Joel; Forte, Stefano; Gao, Jun; Glazov, Sasha; Huston, Joey; Kassabov, Zahari; et al

    2016-01-06

    We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+αs uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new generation of PDFs, which include substantial information from experimental data from the Run I of the LHC. We then propose a new prescription for the combination of a suitable subset of the available PDF sets, which is presented in terms of a single combined PDF set. Lastly, we finally discuss tools which allow for themore » delivery of this combined set in terms of optimized sets of Hessian eigenvectors or Monte Carlo replicas, and their usage, and provide some examples of their application to LHC phenomenology.« less

  3. Sensitivity of LHC experiments to exotic highly ionising particles

    NASA Astrophysics Data System (ADS)

    De Roeck, A.; Katre, A.; Mermod, P.; Milstead, D.; Sloan, T.

    2012-04-01

    The experiments at the Large Hadron Collider (LHC) are able to discover or set limits on the production of exotic particles with TeV-scale masses possessing values of electric and/or magnetic charge such that they behave as highly ionising particles (HIPs). In this paper the sensitivity of the LHC experiments to HIP production is discussed in detail. It is shown that a number of different detection methods are required to investigate as fully as possible the charge-mass range. These include direct detection as the HIPs pass through either passive or active detectors and, in the case of magnetically charged objects, the so-called induction method with which magnetic monopoles which stop in accelerator and detector material could be observed. The benefit of using complementary approaches to HIP detection is discussed.

  4. The seasonal and solar cycle variations of electron density gradient scale length, vertical drift and layer height during magnetically quiet days: Implications for Spread F over Trivandrum, India

    NASA Astrophysics Data System (ADS)

    Manju, G.; Devasia, C. V.; Ravindran, S.

    2009-12-01

    A study has been carried out on the behaviour of electron density gradient scale length, L, vertical drift and layer height, around post sunset hours, during the magnetically quiet days of summer, winter and equinox seasons of solar maximum (2002) and minimum years (1995), using ionosonde data of Trivandrum (8.5°N, 76.5°E, dip = 0.5°N) in the Indian longitude sector. The results indicate a clear seasonal and solar cycle variation in all the three parameters. Further, the seasonal variation of equatorial Spread F (ESF) during the above period is examined in terms of the relative roles of L, the vertical drift and layer height (of the F layer) in the triggering of the collisional Rayleigh-Taylor instability. The results, show for the first time, that L also plays an important role, in controlling the quiet time seasonal and solar cycle variability of ESF; whereas in earlier studies this parameter had been taken to be constant. The detailed results are presented and discussed.

  5. Data Analysis Techniques at LHC

    SciTech Connect

    Boccali, Tommaso

    2005-10-12

    A review of the recent developments on data analysis techniques for the upcoming LHC experiments is presented, with the description of early tests ('Data Challenges'), which are being performed before the start-up, to validate the overall design.

  6. Career Day

    NASA Video Gallery

    NASA's 2013 Career Days was a joint collaboration between NASA Langley and the Newport News Shipbuilding where 600 high school students from Virginia took on two design challenges -- designing a ca...

  7. Design, production and first commissioning results of the electrical feedboxes of the LHC

    SciTech Connect

    Perin, A.; Atieh, S.; Benda, V.; Bertarelli, A.; Bouillot, A.; Brodzinski, K.; Folch, R.; Fydrych, J.; Genet, M.; Koczorowski, S.; Metral, L.; /CERN /Serpukhov, IHEP /Fermilab /CERN /Serpukhov, IHEP /CERN /Serpukhov, IHEP

    2007-12-01

    A total of 44 CERN designed cryogenic electrical feedboxes are needed to power the LHC superconducting magnets. The feedboxes include more than 1000 superconducting circuits fed by high temperature superconductor and conventional current leads ranging from 120 A to 13 kA. In addition to providing the electrical current to the superconducting circuits, they also ensure specific mechanical and cryogenic functions for the LHC. The paper focuses on the main design aspects and related production operations and gives an overview of specific technologies employed. Results of the commissioning of the feedboxes of the first LHC sectors are presented.

  8. Inspire Day

    ERIC Educational Resources Information Center

    Bohach, Barbara M.; Meade, Birgitta

    2014-01-01

    The authors collaborated on hosting a "Spring Inspire Day." planned and delivered by preservice elementary teachers as a social studies/science methods project. Projects that have authentic application opportunities can make learning meaningful for prospective teachers as well as elementary students. With the impetus for an integrated…

  9. Displacement measurements in the cryogenically cooled dipoles of the new CERN-LHC particle accelerator

    NASA Astrophysics Data System (ADS)

    Inaudi, Daniele; Glisic, Branko; Scandale, Walter; Garcia Perez, Juan; Billan, Jaques; Radaelli, Stefano

    2001-08-01

    All evidence indicates that new physics, and answers to some of the most profound scientific questions of our time, lie at energies around 1 TeV. To look for this new physics, the next research instrument in Europe's particle physics armory is the Large Hadron Collider (LHC). This challenging machine will use the most advanced superconducting magnet and accelerator technologies ever employed. LHC experiments are being designed to look for theoretically predicted phenomena.

  10. Development of Nb3Sn 11 T single aperture demonstrator dipole for LHC upgrades

    SciTech Connect

    Zlobin, A.V.; Apollinari, G.; Andreev, N.; Barzi, E.; Kashikhin, V.V.; Nobrega, f.; Novitski, I.; Auchmann, B.; Karppinen, M.; Rossi, L.; /CERN

    2011-03-01

    The LHC collimation upgrade foresees additional collimators installed in dispersion suppressor regions. To obtain the necessary space for the collimators, a solution based on the substitution of LHC main dipoles for stronger dipoles is being considered. CERN and FNAL have started a joint program to demonstrate the feasibility of Nb{sub 3}Sn technology for this purpose. The goal of the first phase is the design and construction of a 2-m long single-aperture demonstrator magnet with a nominal field of 11 T at 11.85 kA with 20% margin. This paper describes the magnetic and mechanical design of the demonstrator magnet and summarizes its design parameters.

  11. Optics Studies of the LHC Beam Transfer Line TI8

    SciTech Connect

    J. Wenninger; G. Arduini; B. Goddard; D. Jacquet; V. Kain; M. Lamont; V. Mertens; J.A. Uythoven; Y.-C. Chao

    2005-05-16

    The optics of the newly commissioned LHC beam transfer line TI 8 was studied with beam trajectories, dispersion and profile measurements. Steering magnet response measurements were used to analyze the quality of the steering magnets and of the beam position monitors. A simultaneous fit of the quadrupole strengths was used to search for setting or calibration errors. Residual coupling between the planes was evaluated using high statistics samples of trajectories. Initial conditions for the optics at the entrance of the transfer line were reconstructed from beam profile measurements with Optical Transition Radiation monitors. The paper presents the various analysis methods and their errors. The expected emittance growth arising from optical mismatch into the LHC is evaluated.

  12. Le LHC, un tunnel cosmique

    ScienceCinema

    None

    2011-10-06

    Et si la lumière au bout du tunnel du LHC était cosmique ? En d?autres termes, qu?est-ce que le LHC peut nous apporter dans la connaissance de l?Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l?univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l?Univers ? La matière noire est-elle détectable au LHC ? L?énergie noire ? Pourquoi l?antimatière accumulée au CERN est-elle si rare dans l?Univers ? Et si le CERN a bâti sa réputation sur l?exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l?évolution cosmique ? Depuis une trentaine d?années, notre compréhension de l?univers dans ses plus grandes dimensions et l?appréhension de son comportement aux plus petites distances sont intimement liées : en quoi le LHC va-t-il tester expérimentalement cette vision unifiée ? Tout public, entrée libre / Réservations au +41 (0)22 767 76 76

  13. Valentine's Day

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02174 Valentine's Day

    This isolated mesa [lower left center of the image] has an almost heart-shaped margin. Happy Valentine's Day from Mars.

    Image information: VIS instrument. Latitude 29.4N, Longitude 79.1E. 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  14. LHC: The Large Hadron Collider

    SciTech Connect

    Lincoln, Don

    2015-03-04

    The Large Hadron Collider (or LHC) is the world’s most powerful particle accelerator. In 2012, scientists used data taken by it to discover the Higgs boson, before pausing operations for upgrades and improvements. In the spring of 2015, the LHC will return to operations with 163% the energy it had before and with three times as many collisions per second. It’s essentially a new and improved version of itself. In this video, Fermilab’s Dr. Don Lincoln explains both some of the absolutely amazing scientific and engineering properties of this modern scientific wonder.

  15. Diffraction dissociation at the LHC

    NASA Astrophysics Data System (ADS)

    Jenkovszky, László; Orava, Risto; Salii, Andrii

    2013-04-01

    We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given.

  16. LHC Symposium 2003: Summary Talk

    SciTech Connect

    Jeffrey A. Appel

    2003-08-12

    This summary talk reviews the LHC 2003 Symposium, focusing on expectations as we prepare to leap over the current energy frontier into new territory. We may learn from what happened in the two most recent examples of leaping into new energy territory. Quite different scenarios appeared in those two cases. In addition, they review the status of the machine and experiments as reported at the Symposium. Finally, I suggest an attitude which may be most appropriate as they look forward to the opportunities anticipated for the first data from the LHC.

  17. L'Aventure du LHC

    ScienceCinema

    None

    2011-10-06

    Cette présentation s?adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l?engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  18. Diffraction dissociation at the LHC

    SciTech Connect

    Jenkovszky, Laszlo; Orava, Risto; Salii, Andrii

    2013-04-15

    We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given.

  19. B Physics at the LHC

    SciTech Connect

    Gersabeck, Marco

    2010-02-10

    The LHC is scheduled to start its first physics data taking period later in 2009. Primarily LHCb but also ATLAS and CMS will start a rich B physics programme with the potential of revealing New Physics in the heavy flavour sector. This contribution will cover the prospects for B physics at the LHC with particular emphasis to early measurements. This includes CP violation measurements in B{sub d}{sup 0} and B{sub s}{sup 0} decays, searches for rare decays such as B{sub s}{sup 0}->{mu}{mu}, as well as semileptonic and radiative channels.

  20. Experimental Methods at the LHC

    NASA Astrophysics Data System (ADS)

    Korytov, Andrey

    The lectures presented below cover the basics of proton-proton collisions at the LHC, the principles of particle detection, the methodologies employed for reconstruction of individual collision events, general strategies for signal event selection, data-driven techniques for evaluating signal efficiencies and background rates, as well as the main statistical concepts used for physics inference from selected data. The described principles and concepts are then illustrated on an example of a search for a Higgs boson and measurement of its properties in the H → ZZ → 4ℓ decay mode. The discussion is largely based on CMS, taken as a representative LHC experiment.

  1. L'Aventure du LHC

    SciTech Connect

    2010-06-11

    Cette présentation s’adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l’engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  2. Testing the Muon g-2 Anomaly at the LHC

    SciTech Connect

    Freitas, Ayres; Lykken, Joseph; Kell, Stefan; Westhoff, Susanne

    2014-05-29

    The long-standing difference between the experimental measurement and the standard-model prediction for the muon's anomalous magnetic moment, $a_{\\mu} = (g_{\\mu}-2)/2$, may be explained by the presence of new weakly interacting particles with masses of a few 100 GeV. Particles of this kind can generally be directly produced at the LHC, and thus they may already be constrained by existing data. In this work, we investigate this connection between $a_{\\mu}$ and the LHC in a model-independent approach, by introducing one or two new fields beyond the standard model with spin and weak isospin up to one. For each case, we identify the preferred parameter space for explaining the discrepancy of a_mu and derive bounds using data from LEP and the 8-TeV LHC run. Furthermore, we estimate how these limits could be improved with the 14-TeV LHC. We find that the 8-TeV results already rule out a subset of our simplified models, while almost all viable scenarios can be tested conclusively with 14-TeV data.

  3. Testing the Muon g-2 Anomaly at the LHC

    DOE PAGESBeta

    Freitas, Ayres; Lykken, Joseph; Kell, Stefan; Westhoff, Susanne

    2014-05-29

    The long-standing difference between the experimental measurement and the standard-model prediction for the muon's anomalous magnetic moment,more » $$a_{\\mu} = (g_{\\mu}-2)/2$$, may be explained by the presence of new weakly interacting particles with masses of a few 100 GeV. Particles of this kind can generally be directly produced at the LHC, and thus they may already be constrained by existing data. In this work, we investigate this connection between $$a_{\\mu}$$ and the LHC in a model-independent approach, by introducing one or two new fields beyond the standard model with spin and weak isospin up to one. For each case, we identify the preferred parameter space for explaining the discrepancy of a_mu and derive bounds using data from LEP and the 8-TeV LHC run. Furthermore, we estimate how these limits could be improved with the 14-TeV LHC. We find that the 8-TeV results already rule out a subset of our simplified models, while almost all viable scenarios can be tested conclusively with 14-TeV data.« less

  4. Hydrology day

    NASA Astrophysics Data System (ADS)

    Morel-Seytoux, H. J.

    Registration for the Hydrology Day sponsored by the Front Range Branch of AGU on April 23 at Colorado State University in Fort Collins, Colorado, totaled 121 participants, of whom 61 were students.Thirty-one individuals joined the Front Range Branch. Three students from Colorado State University won the awards for best paper in their category: Thomas W. Anzia (Sr.), ‘A Comprehensive Table of Standard Deviates for Confidence Limits on Extreme Events’ Victor Nazareth (M.S.), ‘Aquifer Properties from Single-Hole Aquifer Tests’ and Roy W. Koch (Ph.D.), ‘A Physically Based Derivation of the Distribution of Excess Precipitation.’ Judges for the awards were Dr. Bittinger, Resource Consultants, Fort Collins; George Leavesley and Daniel Bauer, USGS, Water Resources Division, Denver; Scott Tucker, Executive Director, Denver Urban Drainage and Flood Control District; Charles Brendecke, Department of Civil Engineering, Univ. of Colorado, Boulder.

  5. Development of NbTi based cables for LHC dipoles

    SciTech Connect

    Ky, H.G.; Grunblatt, G. ); Bonnet, P. )

    1991-03-01

    This paper reports on technology developed at AISA/GEC ALSTROM to meet LHC dipole superconductive cable requirements. The program carried out includes the development of five micron NbTi filament, high Jc and low magnetization elementary strands for high field applications and the manufacturing of large compacted keystone cables. Characteristics of NbTi sc strands and cables manufactured are presented in this paper as well as test results performed at 4.2 K and below for magnetic fields up to 11 Tesla.

  6. String Physics at the LHC

    SciTech Connect

    Anchordoqui, Luis A.

    2008-11-23

    The LHC program will include the identification of events with single high-k{sub T} photons as probes of new physics. We show that this channel is uniquely suited to search for experimental evidence of TeV-scale open string theory.

  7. Event generator for the LHC

    NASA Astrophysics Data System (ADS)

    Gleisberg, T.; Höche, S.; Krauss, F.; Schälicke, A.; Schumann, S.; Winter, J.

    2006-04-01

    In this contribution the new event generation framework S HERPA will be presented. It aims at the full simulation of events at current and future high-energy experiments, in particular the LHC. Some results related to the production of jets at the Tevatron will be discussed.

  8. PHOBOS in the LHC era

    SciTech Connect

    Steinberg, Peter

    2015-01-15

    The PHOBOS experiment ran at the RHIC collider from 2000 to 2005, under the leadership of Wit Busza. These proceedings summarize selected PHOBOS results, highlighting their continuing relevance amidst the wealth of new results from the lead–lead program at the Large Hadron Collider (LHC)

  9. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2012-07-01 2012-07-01 false Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  10. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2010-07-01 2010-07-01 false Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  11. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2014-07-01 2013-07-01 true Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  12. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2011-07-01 2010-07-01 true Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  13. 34 CFR 300.11 - Day; business day; school day.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... included in the designation of business day, as in § 300.148(d)(1)(ii)). (c)(1) School day means any day... 34 Education 2 2013-07-01 2013-07-01 false Day; business day; school day. 300.11 Section 300.11... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.11 Day; business day; school day....

  14. Nb3Sn quadrupoles in the LHC IR Phase I upgrade

    SciTech Connect

    Zlobin, A.V.; Johnstone, J.A.; Kashikhin, V.V.; Mokhov, N.V.; Rakhno, I.L.; de Maria, R.; Peggs, S.; Robert-Demolaize, G.; Wanderer, P.; /Brookhaven

    2008-06-01

    After a number of years of operation at nominal parameters, the LHC will be upgraded to a higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet parameters and issues related to using Nb{sub 3}Sn quadrupoles including aperture, gradient, magnetic length, field quality, operation margin, et cetera are discussed.

  15. Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade

    SciTech Connect

    Zlobin,A.; Johnstone, J.; Kashikhin, V.; Mokhov, N.; Rakhno, I.; deMaria, R.; Peggs, S.; Robert-Demolaize, F.; Wanderer, P.

    2008-06-23

    After a number of years of operation at nominal parameters, the LHC will be upgraded for higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet parameters and issues related to using Nb{sub 3}Sn quadrupoles including aperture, gradient, magnetic length, field quality, operation margin, et cetera are discussed.

  16. Thermo-magnetic instabilities in Nb3Sn superconducting accelerator magnets

    SciTech Connect

    Bordini, Bernardo; /Pisa U.

    2006-09-01

    The advance of High Energy Physics research using circulating accelerators strongly depends on increasing the magnetic bending field which accelerator magnets provide. To achieve high fields, the most powerful present-day accelerator magnets employ NbTi superconducting technology; however, with the start up of Large Hadron Collider (LHC) in 2007, NbTi magnets will have reached the maximum field allowed by the intrinsic properties of this superconductor. A further increase of the field strength necessarily requires a change in superconductor material; the best candidate is Nb{sub 3}Sn. Several laboratories in the US and Europe are currently working on developing Nb{sub 3}Sn accelerator magnets, and although these magnets have great potential, it is suspected that their performance may be fundamentally limited by conductor thermo-magnetic instabilities: an idea first proposed by the Fermilab High Field Magnet group early in 2003. This thesis presents a study of thermo-magnetic instability in high field Nb{sub 3}Sn accelerator magnets. In this chapter the following topics are described: the role of superconducting magnets in High Energy Physics; the main characteristics of superconductors for accelerator magnets; typical measurements of current capability in superconducting strands; the properties of Nb{sub 3}Sn; a description of the manufacturing process of Nb{sub 3}Sn strands; superconducting cables; a typical layout of superconducting accelerator magnets; the current state of the art of Nb{sub 3}Sn accelerator magnets; the High Field Magnet program at Fermilab; and the scope of the thesis.

  17. Simplified SIMPs and the LHC

    NASA Astrophysics Data System (ADS)

    Daci, N.; De Bruyn, I.; Lowette, S.; Tytgat, M. H. G.; Zaldivar, B.

    2015-11-01

    The existence of Dark Matter (DM) in the form of Strongly Interacting Massive Particles (SIMPs) may be motivated by astrophysical observations that challenge the classical Cold DM scenario. Other observations greatly constrain, but do not completely exclude, the SIMP alternative. The signature of SIMPs at the LHC may consist of neutral, hadron-like, trackless jets produced in pairs. We show that the absence of charged content can provide a very efficient tool to suppress dijet backgrounds at the LHC, thus enhancing the sensitivity to a potential SIMP signal. We illustrate this using a simplified SIMP model and present a detailed feasibility study based on simulations, including a dedicated detector response parametrization. We evaluate the expected sensitivity to various signal scenarios and tentatively consider the exclusion limits on the SIMP elastic cross section with nucleons.

  18. Catching Collisions in the LHC

    SciTech Connect

    Fruguiele, Claudia; Hirschauer, Jim

    2015-06-16

    Now that the Large Hadron Collider has officially turned back on for its second run, within every proton collision could emerge the next new discovery in particle physics. Learn how the detectors on the Compact Muon Solenoid, or CMS, experiment capture and track particles as they are expelled from a collision. Talking us through these collisions are Claudia Fruguiele and Jim Hirschauer of Fermi National Accelerator Laboratory, the largest U.S. institution collaborating on the LHC.

  19. hhjj production at the LHC

    DOE PAGESBeta

    Dolan, Matthew J.; Englert, Christoph; Greiner, Nicolas; Nordstrom, Karl; Spannowsky, Michael

    2015-08-25

    The search for di-Higgs production at the LHC in order to set limits on the Higgs trilinear coupling and constraints on new physics is one of the main motivations for the LHC high-luminosity phase. Recent experimental analyses suggest that such analyses will only be successful if information from a range of channels is included. We therefore investigate di-Higgs production in association with two hadronic jets and give a detailed discussion of both the gluon- and the weak boson-fusion (WBF) contributions, with a particular emphasis on the phenomenology with modified Higgs trilinear and quartic gauge couplings. We perform a detailed investigationmore » of the full hadronic final state and find that hhjj production should add sensitivity to a di-Higgs search combination at the HL-LHC with 3 ab-1. Since the WBF and GF contributions are sensitive to different sources of physics beyond the Standard Model, we devise search strategies to disentangle and isolate these production modes. In addition, while gluon fusion remains non-negligible in WBF-type selections, sizeable new physics contributions to the latter can still be constrained. As an example of the latter point we investigate the sensitivity that can be obtained for a measurement of the quartic Higgs–gauge boson couplings.« less

  20. Cryogenics for HL-LHC

    NASA Astrophysics Data System (ADS)

    Tavian, L.; Brodzinski, K.; Claudet, S.; Ferlin, G.; Wagner, U.; van Weelderen, R.

    The discovery of a Higgs boson at CERN in 2012 is the start of a major program of work to measure this particle's properties with the highest possible precision for testing the validity of the Standard Model and to search for further new physics at the energy frontier. The LHC is in a unique position to pursue this program. Europe's top priority is the exploitation of the full potential of the LHC, including the high-luminosity upgrade of the machine and detectors with an objective to collect ten times more data than in the initial design, by around 2030. To reach this objective, the LHC cryogenic system must be upgraded to withstand higher beam current and higher luminosity at top energy while keeping the same operation availability by improving the collimation system and the protection of electronics sensitive to radiation. This chapter will present the conceptual design of the cryogenic system upgrade with recent updates in performance requirements, the corresponding layout and architecture of the system as well as the main technical challenges which have to be met in the coming years.

  1. Cryogenic safety aspect of the low -$\\beta$ magnest systems at the Large Hadron Collider (LHC)

    SciTech Connect

    Darve, C.; /Fermilab

    2010-07-01

    The low-{beta} magnet systems are located in the LHC insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process and will allow proton collisions at a luminosity of up to 10{sup 34}cm{sup -2}s{sup -1}. Large radiation dose deposited at the proximity of the beam collisions dictate stringent requirements for the design and operation of the systems. The hardware commissioning phase of the LHC was completed in the winter of 2010 and permitted to validate this system safe operation. This paper presents the analysis used to qualify and quantify the safe operation of the low-{beta} magnet systems in the Large Hadron Collider (LHC) for the first years of operation.

  2. Support Structure Design of the $$\\hbox{Nb}_{3}\\hbox{Sn}$$ Quadrupole for the High Luminosity LHC

    DOE PAGESBeta

    Juchno, M.; Ambrosio, G.; Anerella, M.; Cheng, D.; Felice, H.; Ferracin, P.; Perez, J. C.; Prin, H.; Schmalzle, J.

    2014-10-31

    New low-β quadrupole magnets are being developed within the scope of the High Luminosity LHC (HL-LHC) project in collaboration with the US LARP program. The aim of the HLLHC project is to study and implement machine upgrades necessary for increasing the luminosity of the LHC. The new quadrupoles, which are based on the Nb₃Sn superconducting technology, will be installed in the LHC Interaction Regions and will have to generate a gradient of 140 T/m in a coil aperture of 150 mm. In this paper, we describe the design of the short model magnet support structure and discuss results of themore » detailed 3D numerical analysis performed in preparation for the first short model test.« less

  3. QCD and hard diffraction at the LHC

    SciTech Connect

    Albrow, Michael G.; /Fermilab

    2005-09-01

    As an introduction to QCD at the LHC the author gives an overview of QCD at the Tevatron, emphasizing the high Q{sup 2} frontier which will be taken over by the LHC. After describing briefly the LHC detectors the author discusses high mass diffraction, in particular central exclusive production of Higgs and vector boson pairs. The author introduces the FP420 project to measure the scattered protons 420m downstream of ATLAS and CMS.

  4. Abort Gap Cleaning for LHC Run 2

    SciTech Connect

    Uythoven, Jan; Boccardi, Andrea; Bravin, Enrico; Goddard, Brennan; Hemelsoet, Georges-Henry; Höfle, Wolfgang; Jacquet, Delphine; Kain, Verena; Mazzoni, Stefano; Meddahi, Malika; Valuch, Daniel; Gianfelice-Wendt, Eliana

    2014-07-01

    To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.

  5. LHC crab-cavity aspects and strategy

    SciTech Connect

    Calaga, R.; Tomas, R.; Zimmermann, F.

    2010-05-23

    The 3rd LHC Crab Cavity workshop (LHC-CC09) took place at CERN in October 2009. It reviewed the current status and identified a clear strategy towards a future crab-cavity implementation. Following the success of crab cavities in KEK-B and the strong potential for luminosity gain and leveling, CERN will pursue crab crossing for the LHC upgrade. We present a summary and outcome of the variousworkshop sessions which have led to the LHC crab-cavity strategy, covering topics like layout, cavity design, integration, machine protection, and a potential validation test in the SPS.

  6. MAGNETS

    DOEpatents

    Hofacker, H.B.

    1958-09-23

    This patent relates to nmgnets used in a calutron and more particularly to means fur clamping an assembly of magnet coils and coil spacers into tightly assembled relation in a fluid-tight vessel. The magnet comprises windings made up of an assembly of alternate pan-cake type coils and spacers disposed in a fluid-tight vessel. At one end of the tank a plurality of clamping strips are held firmly against the assembly by adjustable bolts extending through the adjacent wall. The foregoing arrangement permits taking up any looseness which may develop in the assembly of coils and spacers.

  7. Production and installation of the LHC low-beta triplets

    SciTech Connect

    Feher, S.; Bossert, R.; DiMarco, J.; Karppinen, M.; Kerby, J.; Kimura, N.; Lamm, M.J.; Nakamoto, T.; Nicol, T.; Nobrega, A.; Ogitsu, T.; Ohuchi, N.; Ostojic, R.; Page, T.; Peterson, T.; Rabehl, R.; Schlabach, P.; Shintomi, T.; Strait, J.; Sylvester, C.; Tartaglia, M.; /Fermilab /CERN /KEK, Tsukuba

    2005-09-01

    The LHC performance depends critically on the low-{beta}, triplets, located on either side of the four interaction points. Each triplet consists of four superconducting quadrupole magnets, which must operate reliably at up to 215 T/m, sustain extremely high heat loads and have an excellent field quality. A collaboration of CERN, Fermilab and KEK was formed in 1996 to design and build the triplet systems, and after nine years of joint effort the production has been completed in 2005. We retrace the main events of the project and present the design features and performance of the low-{beta} quadrupoles, built by KEK and Fermilab, as well as of other vital elements of the triplet. The tunnel installation of the first triplet and plans for commissioning in the LHC are also presented. Apart from the excellent technical results, the construction of the LHC low-{beta} triplets has been a highly enriching experience combining harmoniously the different competences and approaches to engineering in a style reminiscent of high energy physics experiment collaborations, and rarely before achieved in construction of an accelerator.

  8. Size and stiffness measurements on 9.5 m long LHC dipole coils

    SciTech Connect

    Zerobin, F.; Painer, M.; Eichberger, S.; Pichler, S.

    1994-07-01

    For a 10 m long superconducting dipole prototype magnet for CERN`s LHC program in total 17 dummy and superconducting coils were manufactured at ELIN company. The paper presents measurements taken during coil manufacturing. The results are compared to results obtained on models. The influence of cable dimensions on the final dimension and the Young`s Modulus of the coils is described.

  9. Weak-strong Beam-beam Simulations for HL-LHC

    SciTech Connect

    Banfi, Danilo; Barranco, Javier; Pieloni, Tatiana; Valishev, Alexander

    2014-07-01

    In this paper we present dynamic aperture studies for possible High Luminosity LHC optics in the presence of beam-beam interactions, crab crossing schemes and magnets multipolar errors. Possible operational scenarios of luminosity leveling by transverse offset and betatron function are also studied and the impact on the beams stability is discussed.

  10. Manufacturing experience for the LHC inner triplet quadrupole cables

    SciTech Connect

    Scanlan, R.M.; Higley, H.C.; Bossert, R.; Kerby, J.; Gosh, A.K.; Boivin, M.; Roy, T.

    2001-06-12

    The design for the U.S. LHC Inner Triplet Quadrupole magnet requires a 37 strand (inner layer) and a 46 strand (outer layer) cable. This represents the largest number of strands attempted to date for a production quantity of Rutherford-type cable. The cable parameters were optimized during the production of a series of short prototype magnets produced at FNAL. These optimization studies focused on critical current degradation, dimensional control, coil winding, and interstrand resistance. After the R&D phase was complete, the technology was transferred to NEEW and a new cabling machine was installed to produce these cables. At present, about 60 unit lengths, out of 90 required for the entire production series of magnets, have been completed for each type of cable. The manufacturing experience with these challenging cables will be reported. Finally, the implications for even larger cables, with more strands, will be discussed.

  11. Ambient temperature field measuring system for LHC superconducting dipoles

    SciTech Connect

    Billan, J.; De Panfilis, S.; Giloteaux, D.; Pagano, O.

    1996-07-01

    It is foreseen to perform acceptance tests including field measurements of the collared coils assembly of the LHC superconducting dipoles to estimate, at an early production stage, the possible significant deviations from the expected multipole component value of these magnets. A sensitive measuring probe and efficient data acquisition are the consequence of a low magnetizing current necessary to limit the coils heating. This demands a high signals sensitivity and an enhanced signal-to-noise ratio to retrieve the higher multipole component. Moreover, the correlation with the multipoles content of the magnets at cryogenic temperature and nominal excitation current need to be identified before the manufacturing process may continue. The field probe of the mole-type is equipped with three radial rotating search coils, an angular encoder and gravity sensor. It has been designed to slide inside the bore of the dipole coils and to measure the local field at fixed positions. The field analysis resulting in terms of multipole components, field direction and field integrals, measured on four 10 m long, twin-aperture LHC dipole prototypes, will be described together with the performance of the measuring method.

  12. Energy deposited in the high luminosity inner triplets of the LHC by collision debris

    SciTech Connect

    Wildner, E.; Broggi, F.; Cerutti, F.; Ferrari, A.; Hoa, C.; Koutchouk, J.-P.; Mokhov, N.V.; /Fermilab

    2008-06-01

    The 14 TeV center of mass proton-proton collisions in the LHC produce not only debris interesting for physics but also showers of particles ending up in the accelerator equipment, in particular in the superconducting magnet coils. Evaluations of this contribution to the heat, that has to be transported by the cryogenic system, have been made to guarantee that the energy deposition in the superconducting magnets does not exceed limits for magnet quenching and the capacity of the cryogenic system. The models of the LHC base-line are detailed and include description of, for energy deposition, essential elements like beam-pipes and corrector magnets. The evaluations made using the Monte-Carlo code FLUKA are compared to previous studies using MARS. For the consolidation of the calculations, a dedicated comparative study of these two codes was performed for a reduced setup.

  13. Z' Phenomenology and the LHC

    SciTech Connect

    Rizzo, Thomas G.

    2006-10-17

    A brief pedagogical overview of the phenomenology of Z{prime} gauge bosons is ILC in determining Z{prime} properties is also discussed. and explore in detail how the LHC may discover and help elucidate the models, review the current constraints on the possible properties of a Z{prime} nature of these new particles. We provide an overview of the Z{prime} studies presented. Such particles can arise in various electroweak extensions of that have been performed by both ATLAS and CMS. The role of the the Standard Model (SM). We provide a quick survey of a number of Z{prime}.

  14. Probing Metastability at the LHC

    SciTech Connect

    Clavelli, L.

    2010-02-10

    Current attempts to understand supersymmetry (susy) breaking are focused on the idea that we are not in the ground state of the universe but, instead, in a metastable state that will ultimately decay to an exactly susy ground state. It is interesting to ask how experiments at the Large Hadron Collider (LHC) will shed light on the properties of this future supersymmetric universe. In particular we ask how we can determine whether this final state has the possibility of supporting atoms and molecules in a susy background.

  15. (SUSY) Higgs Search at the LHC

    SciTech Connect

    Muehlleitner, M. Margarete

    2008-11-23

    The discovery of the Standard Model (SM) or supersymmetric (SUSY) Higgs bosons belongs to the main endeavors of the Large Hadron Collider (LHC). In this article the status of the signal and background calculations for Higgs boson production at the LHC is reviewed.

  16. First data from TOTEM experiment at LHC

    NASA Astrophysics Data System (ADS)

    Ferro, F.

    2011-07-01

    The TOTEM experiment at the LHC is mainly dedicated to the measurement of the total proton-proton cross section, elastic scattering and to the study of the diffractive processes. This contribution reviews the physics goals of the experiment, the status of the experimental apparatus and of the analysis of the first data from the LHC.

  17. Calibration of Cryogenic Thermometers for the Lhc

    NASA Astrophysics Data System (ADS)

    Balle, Ch.; Casas-Cubillos, J.; Vauthier, N.; Thermeau, J. P.

    2008-03-01

    6000 cryogenic temperature sensors of resistive type covering the range from room temperature down to 1.6 K are installed on the LHC machine. In order to meet the stringent requirements on temperature control of the superconducting magnets, each single sensor needs to be calibrated individually. In the framework of a special contribution, IPN (Institut de Physique Nucléaire) in Orsay, France built and operated a calibration facility with a throughput of 80 thermometers per week. After reception from the manufacturer, the thermometer is first assembled onto a support specific to the measurement environment, and then thermally cycled ten times and calibrated at least once from 1.6 to 300 K. The procedure for each of these interventions includes various measurements and the acquired data is recorded in an ORACLE®-database. Furthermore random calibrations on some samples are executed at CERN to crosscheck the coherence between the approximation data obtained by both IPN and CERN. In the range of 1.5 K to 30 K, the calibration apparatuses at IPN and CERN are traceable to standards maintained in a national metrological laboratory by using a set of rhodium-iron temperature sensors of metrological quality. This paper presents the calibration procedure, the quality assurance applied, the results of the calibration campaigns and the return of experience.

  18. LARP Long Quadrupole: A "Long" Step Toward an LHC

    ScienceCinema

    Giorgio Ambrosio

    2010-01-08

    The beginning of the development of Nb3Sn magnets for particle accelerators goes back to the 1960?s. But only very recently has this development begun to face the challenges of fabricating Nb3Sn magnets which can meet the requirements of modern particle accelerators. LARP (the LHC Accelerator Research Program) is leading this effort focusing on long models of the Interaction Region quadrupoles for a possible luminosity upgrade of the Large Hadron Collider. A major milestone in this development is to test, by the end of 2009, 4m-long quadrupole models, which will be the first Nb3Sn accelerator-type magnets approaching the length of real accelerator magnets. The Long Quadrupoles (LQ) are ?Proof-of-Principle? magnets which are to demonstrate that Nb3Sn technology is sufficiently mature for use in high energy particle accelerators. Their design is based on the LARP Technological Quadrupole (TQ) models, under development at FNAL and LBNL, which have design gradients higher than 200 T/m and an aperture of 90 mm. Several challenges must be addressed for the successful fabrication of long Nb3Sn coils and magnets. These challenges and the solutions adopted will be presented together with the main features of the LQ magnets. Several R&D lines are participating to this effort and their contributions will be also presented.

  19. Remote Operations for LHC and CMS

    SciTech Connect

    Gottschalk, E.E.; /Fermilab

    2007-04-01

    Commissioning the Large Hadron Collider (LHC) and its experiments will be a vital part of the worldwide high energy physics program beginning in 2007. A remote operations center has been built at Fermilab to contribute to commissioning and operations of the LHC and the Compact Muon Solenoid (CMS) experiment, and to develop new capabilities for real-time data analysis and monitoring for LHC, CMS, and grid computing. Remote operations will also be essential to a future International Linear Collider with its multiple, internationally distributed control rooms. In this paper we present an overview of Fermilab's LHC@FNAL remote operations center for LHC and CMS, describe what led up to the development of the center, and describe noteworthy features of the center.

  20. String photini at the LHC

    SciTech Connect

    Arvanitaki, Asimina; Craig, Nathaniel; Dimopoulos, Savas; Dubovsky, Sergei; March-Russell, John

    2010-04-01

    String theories with topologically complex compactification manifolds suggest the simultaneous presence of many unbroken U(1)'s without any light matter charged under them. The gauge bosons associated with these U(1)'s do not have direct observational consequences. However, in the presence of low energy supersymmetry the gauge fermions associated with these U(1)'s, the ''photini,'' mix with the bino and extend the minimal supersymmetric standard model neutralino sector. This leads to novel signatures at the LHC. The lightest ordinary supersymmetric particle (LOSP) can decay to any one of these photini. In turn, photini may transition into each other, leading to high lepton and jet multiplicities. Both the LOSP decays and interphotini transitions can lead to displaced vertices. When the interphotini decays happen outside the detector, the cascades can result in different photini escaping the detector, leading to multiple reconstructed masses for the invisible particle. If the LOSP is charged, it stops in the detector and decays out of time to photini, with the possibility that the produced final photini vary from event to event. Observation of a plenitude of photini at the LHC would be evidence that we live in a string vacuum with a topologically rich compactification manifold.

  1. Quench antenna studies of mechanical and quench performance in Fermilab interaction region quadrupoles for LHC

    SciTech Connect

    Tartaglia, M.A.; Feher, S.; Hocker, A.; Lamm, M.; Schlabach, P.; Sylvester, C.; Tompkins, J.C.; /Fermilab

    2005-09-01

    As part of the US-LHC collaboration, Fermilab has built and tested seventeen high gradient quadrupole magnets, assembled into nine cryostats, for installation at the Large Hadron Collider Interaction Regions. Most of these magnets have only quarter coil voltage taps for quench characterization, but the magnetic measurement warm bore is instrumented with a quench antenna for localization and characterization. We report on studies using the quench antenna for pre-production prototype (with extensive voltage taps) and 17 production magnets. These include a summary of quench localization and development characteristics, as well as general features of flux changes observed during training ramps.

  2. Design and Fabrication of a Single-Aperture 11T Nb3Sn Dipole Model for LHC Upgrades

    SciTech Connect

    Andreev, N.; Apollinari, G.; Barzi, E.; Bossert, R.; Nobrega, F.; Novitski, I.; Turrioni, D.; Yamada, R.; Zlobin, A.V.; Auchmann, B.; Karppinen, M.; /CERN

    2011-11-28

    The planned upgrade of the LHC collimation system includes additional collimators to be installed in the dispersion suppressor areas of points 2, 3 and 7. To provide the necessary longitudinal space for the collimators, a replacement of 8.33 T Nb-Ti LHC main dipoles with 11 T dipoles based on Nb{sub 3}Sn superconductor compatible with the LHC lattice and main systems is being considered. To demonstrate this possibility FNAL and CERN have started a joint program to develop a 2 m long single-aperture dipole magnet with the nominal field of 11 T at {approx}11.85 kA current and 60 mm bore. This paper describes the demonstrator magnet magnetic and mechanical designs and analysis, coil fabrication procedure. The Nb{sub 3}Sn strand and cable parameters and test results are also reported.

  3. Changes to the Transfer Line Collimation System for the High-Luminosity LHC Beams

    SciTech Connect

    Kain, V.; Aberle, O.; Bracco, C.; Fraser, M.; Galleazzi, F.; Gianfelice-Wendt, E.; Kosmicki, A.; Maciariello, F.; Meddahi, M.; Nuiry, F. X.; Steele, G.; Velotti, F.

    2015-06-01

    The current LHC transfer line collimation system will not be able to provide enough protection for the high brightness beams in the high-luminosity LHC era. The new collimation system will have to attenuate more and be more robust than its predecessor. The active jaw length of the new transfer line collimators will therefore be 2.1 m instead of currently 1.2 m. The transfer line optics will have to be adjusted for the new collimator locations and larger beta functions at the collimators for absorber robustness reasons. In this paper the new design of the transfer line collimation system will be presented with its implications on transfer line optics and powering, maintainability, protection of transfer line magnets in case of beam loss on a collimator and protection of the LHC aperture.

  4. Probing top-Z dipole moments at the LHC and ILC

    SciTech Connect

    Röntsch, Raoul; Schulze, Markus

    2015-08-11

    We investigate the weak electric and magnetic dipole moments of top quark-Z boson interactions at the Large Hadron Collider (LHC) and the International Linear Collider (ILC). Their vanishingly small magnitude in the Standard Model makes these couplings ideal for probing New Physics interactions and for exploring the role of top quarks in electroweak symmetry breaking. In our analysis, we consider the production of two top quarks in association with a Z boson at the LHC, and top quark pairs mediated by neutral gauge bosons at the ILC. These processes yield direct sensitivity to top quark-Z boson interactions and complement indirect constraints from electroweak precision data. Our computation is accurate to next-to-leading order in QCD, we include the full decay chain of top quarks and the Z boson, and account for theoretical uncertainties in our constraints. Furthermore, we find that LHC experiments will soon be able to probe weak dipole moments for the first time.

  5. EXERGY ANALYSIS OF THE CRYOGENIC HELIUM DISTRIBUTION SYSTEM FOR THE LARGE HADRON COLLIDER (LHC)

    SciTech Connect

    Claudet, S.; Lebrun, Ph.; Tavian, L.; Wagner, U.

    2010-04-09

    The Large Hadron Collider (LHC) at CERN features the world's largest helium cryogenic system, spreading over the 26.7 km circumference of the superconducting accelerator. With a total equivalent capacity of 145 kW at 4.5 K including 18 kW at 1.8 K, the LHC refrigerators produce an unprecedented exergetic load, which must be distributed efficiently to the magnets in the tunnel over the 3.3 km length of each of the eight independent sectors of the machine. We recall the main features of the LHC cryogenic helium distribution system at different temperature levels and present its exergy analysis, thus enabling to qualify second-principle efficiency and identify main remaining sources of irreversibility.

  6. OPEN MIDPLANE DIPOLE DESIGN FOR LHC IR UPGRADE.

    SciTech Connect

    GUPTA,R.; ANERELLA,M.; HARRISON,M.; SCHMALZLE,J.; MOKHOV,N.

    2004-01-21

    The proposed luminosity upgrade of the Large Hadron Collider (LHC), now under construction, will bring a large increase in the number of secondary particles from p-p collisions at the interaction point (IP). Energy deposition will be so large that the lifetime and quench performance of interaction region (IR) magnets may be significantly reduced if conventional designs are used. Moreover, the cryogenic capacity of the LHC will have to be significantly increased as the energy deposition load on the interaction region (IR) magnets by itself will exhaust the present capacity. We propose an alternate open midplane dipole design concept for the dipole-first optics that mitigates these issues. The proposed design takes advantage of the fact that most of the energy is deposited in the midplane region. The coil midplane region is kept free of superconductor, support structure and other material. Initial energy deposition calculations show that the increase in temperature remains within the quench tolerance of the superconducting coils. In addition, most of the energy is deposited in a relatively warm region where the heat removal is economical. We present the basic concept and preliminary design that includes several innovations.

  7. PROCEEDINGS OF THE WORKSHOP ON LHC INTERACTION REGION CORRECTION SYSTEMS

    SciTech Connect

    FISCHER,W.; WEI,J.

    1999-09-02

    The Workshop on LHC Interaction Region Correction Systems was held at Brookhaven National Laboratory, Upton, New York, on 6 and 7 May 1999. It was attended by 25 participants from 5 institutions. The performance of the Large Hadron Collider (LHC) at collision energy is limited by the field quality of the interaction region quadrupoles and dipoles. In three sessions the workshop addressed the field quality of the these magnets, reviewed the principles and efficiency of global and local correction schemes and finalized a corrector layout. The session on Field Quality Issues, chaired by J. Strait (FNAL), discussed the progress made by KEK and FNAL in achieving the best possible field quality in the interaction region quadrupoles. Results of simulation studies were presented that assess the effects of magnetic field errors with simulation studies. Attention was given to the uncertainties in predicting and measuring field errors. The session on Global Correction, chaired by J.-P. Koutchouk (CERN), considered methods of reducing the nonlinear detuning or resonance driving terms in the accelerator one-turn map by either sorting or correcting. The session also discussed the crossing angle dependence of the dynamic aperture and operational experience from LEP. The session on Local Correction, chaired by T. Taylor (CERN), discussed the location, strength and effectiveness of multipole correctors in the interaction regions for both proton and heavy ion operation. Discussions were based on technical feasibility considerations and dynamic aperture requirements. The work on linear corrections in the interaction regions was reviewed.

  8. Nb3Sn Quadrupoles Designs For The LHC Upgrades

    SciTech Connect

    Felice, Helene

    2008-05-19

    In preparation for the LHC luminosity upgrades, high field and large aperture Nb{sub 3}Sn quadrupoles are being studied. This development has to incorporate all the relevant features for an accelerator magnet like alignment and cooling channels. The LARP HQ model is a high field and large bore quadrupole that will meet these requirements. The 2-layer coils are surrounded by a structure based on key and bladder technology with supporting iron yoke and aluminum shell. This structure is aimed at pre-stress control, alignment and field quality. We present here the magnetic and mechanical design of HQ, along with recent progress on the development of the first 1-meter model.

  9. The LHC Confronts the pMSSM

    DOE PAGESBeta

    Cahill-Rowley, Matthew

    2016-05-31

    Here we explore the impact of current (7+8 TeV) and future (14 TeV) LHC searches on the range of viable sparticle spectra within the 19/20 – dimensional phenomenological MSSM (pMSSM). Considering both neutralino and gravitino LSPs, we compare our results with simplified model exclusion limits and describe important cases where the pMSSM results differ significantly from the simplified model descriptions. We also consider models that are poorly constrained by LHC data because of unusual decay topologies and/or displaced decays, and discuss ways to improve the LHC sensitivity in these scenarios. Finally, motivated by naturalness, we examine the sensitivity of currentmore » searches to models with light stops and to a specialized set of models with fine-tuning better than 1%. We show that the 14 TeV LHC will be a very powerful probe of natural pMSSM models.« less

  10. Double Pomeron physics at the LHC

    SciTech Connect

    Albrow, Michael G.; /Fermilab

    2005-07-01

    The author discusses central exclusive production, also known as Double Pomeron Exchange DIPE, from the ISR through the Tevatron to the LHC. There the author emphasizes the interest of exclusive Higgs and W{sup +}W{sup -}/ZZ production.

  11. Physics motivations for SSC/LHC detectors

    SciTech Connect

    Hinchliffe, I.

    1993-06-01

    In this talk, I review the some of the physics goals and simulation work done in the SSC and LHC experimental proposal. I select the processes that illustrate the strengths and weaknesses the proposed detectors.

  12. Tension in the LHC diffractive data?

    SciTech Connect

    Gotsman, Errol

    2015-04-10

    I discuss the LHC diffractive data, and compare it to predicted energy behaviour of various models. I suggest that the so called 'tension' between the experimental results, maybe due to the different Monte Carlo programs used.

  13. Diffraction at the Tevatron and the LHC

    NASA Astrophysics Data System (ADS)

    Royon, C.

    2008-09-01

    In this paper, we present and discuss the most recent results on inclusive diffraction at the Tevatron collider and give the prospects at the LHC. We also describe the search for exclusive events at the Tevatron. Of special interest is the exclusive production of Higgs boson and heavy objects (W, top, stop pairs) at the LHC which will require precise measurements and analyses of inclusive and exclusive diffraction to constrain further the gluon density in the pomeron. At the end of the paper, we describe the projects to install forward detectors at the LHC to fulfil these measurements. We also describe the diffractive experiments accepted or in project at the LHC: TOTEM, ALFA in ATLAS, and the AFP/FP420 projects.

  14. The TOTEM Experiment at the LHC

    NASA Astrophysics Data System (ADS)

    Avati, V.; Totem Collaboration

    The TOTEM experiment at the LHC will measure the total pp cross-section, elastic scattering and diffraction. This contribution summarises the physics goals, the status of the experimental apparatus and the first results from the 2010 data taking.

  15. Supersymmetry Breaking, Gauge Mediation, and the LHC

    SciTech Connect

    Shih, David

    2015-04-14

    Gauge mediated SUSY breaking (GMSB) is a promising class of supersymmetric models that automatically satisfies the precision constraints. Prior work of Meade, Seiberg and Shih in 2008 established the full, model-independent parameter space of GMSB, which they called "General Gauge Mediation" (GGM). During the first half of 2010-2015, Shih and his collaborators thoroughly explored the parameter space of GGM and established many well-motivated benchmark models for use by the experimentalists at the LHC. Through their work, the current constraints on GGM from LEP, the Tevatron and the LHC were fully elucidated, together with the possible collider signatures of GMSB at the LHC. This ensured that the full discovery potential for GGM could be completely realized at the LHC.

  16. Unravelling strings at the CERN LHC

    SciTech Connect

    Kane, Gordon L.; Kumar, Piyush; Shao Jing

    2008-06-01

    We construct LHC signature footprints for four semirealistic string/M theory vacua with a minimal supersymmetric standard model visible sector. We find that they all give rise to limited regions in LHC signature space and are qualitatively different from each other for understandable reasons. We also propose a technique in which correlations of LHC signatures can be effectively used to distinguish among these string theory vacua. We expect the technique to be useful for more general string vacua. We argue that further systematic analysis with this approach will allow LHC data to disfavor or exclude major 'corners' of string/M theory and favor others. The technique can be used with limited integrated luminosity and improved.

  17. When Every Day Is Professional Development Day

    ERIC Educational Resources Information Center

    Tienken, Christopher H.; Stonaker, Lew

    2007-01-01

    In the Monroe Township (New Jersey) Public Schools, teachers' learning occurs daily, not just on one day in October and February. Central office and school-level administrators foster job-embedded teacher growth. Every day is a professional development day in the district, but that has not always been so. How did the district become a system with…

  18. Physics at the LHC: a short overview

    NASA Astrophysics Data System (ADS)

    d'Enterria, David

    2011-01-01

    The CERN Large Hadron Collider (LHC) started operation a few months ago. The machine will deliver proton-proton and nucleus-nucleus collisions at energies as high as = 14 TeV and luminosities up to ~ 1034 cm-2s-1 never reached before. The main open scientific questions that the seven LHC experiments - ATLAS, CMS, ALICE, LHCb, TOTEM, LHCf and MOEDAL - aim to solve in the coming years are succinctly reviewed.

  19. Charm quark energy loss in proton-proton collisions at LHC energies

    NASA Astrophysics Data System (ADS)

    Vogel, Sascha; Gossiaux, Pol Bernard; Werner, Klaus; Aichelin, Jörg

    2013-03-01

    Heavy quarks, i.e. charm and bottom quarks are one of the crucial probes in the high energy nuclear collision program at current day accelerators. It has been shown at the Relativistic Heavy Ion Collider (RHIC) that heavy quarks show a remarkable medium suppression despite their high mass. In these proceedings we report on a study of heavy quark energy loss in high multiplicity proton-proton collisions at energies accessible to the Large Hadron Collider (LHC). Recent experimental results from the LHC collaborations have shown that the notion of creating an interacting system is not completely off limits. The higher energies in LHC proton-proton collisions lead to multiplicities comparable to Cu+Cu collisions at RHIC. Within this environment high-momentum heavy quarks experience a non-negligible energy loss.

  20. Magnetic

    NASA Astrophysics Data System (ADS)

    Aboud, Essam; El-Masry, Nabil; Qaddah, Atef; Alqahtani, Faisal; Moufti, Mohammed R. H.

    2015-06-01

    The Rahat volcanic field represents one of the widely distributed Cenozoic volcanic fields across the western regions of the Arabian Peninsula. Its human significance stems from the fact that its northern fringes, where the historical eruption of 1256 A.D. took place, are very close to the holy city of Al-Madinah Al-Monawarah. In the present work, we analyzed aeromagnetic data from the northern part of Rahat volcanic field as well as carried out a ground gravity survey. A joint interpretation and inversion of gravity and magnetic data were used to estimate the thickness of the lava flows, delineate the subsurface structures of the study area, and estimate the depth to basement using various geophysical methods, such as Tilt Derivative, Euler Deconvolution and 2D modeling inversion. Results indicated that the thickness of the lava flows in the study area ranges between 100 m (above Sea Level) at the eastern and western boundaries of Rahat Volcanic field and getting deeper at the middle as 300-500 m. It also showed that, major structural trend is in the NW direction (Red Sea trend) with some minor trends in EW direction.

  1. From the LHC to Future Colliders

    SciTech Connect

    De Roeck, A.; Ellis, J.; Grojean, C.; Heinemeyer, S.; Jakobs, K.; Weiglein, G.; Azuelos, G.; Dawson, S.; Gripaios, B.; Han, T.; Hewett, J.; Lancaster, M.; Mariotti, C.; Moortgat, F.; Moortgat-Pick, G.; Polesello, G.; Riemann, S.; Assamagan, K.; Bechtle, P.; Carena, M.; Chachamis, G.; /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.

  2. Quench Protection Studies of 11T Nb$_3$Sn Dipole Models for LHC Upgrades

    SciTech Connect

    Zlobin, Alexander; Chlachidze, Guram; Nobrega, Alfred; Novitski, Igor; Karppinen, Mikko

    2014-07-01

    CERN and FNAL are developing 11 T Nb3Sn dipole magnets for the LHC collimation system upgrade. Due to the large stored energy, protection of these magnets during a quench is a challenging problem. This paper reports the results of experimental studies of key quench protection parameters including longitudinal and radial quench propagation in the coil, coil heating due to a quench, and energy extraction and quench-back effect. The studies were performed using a 1 m long 11 T Nb3Sn dipole coil tested in a magnetic mirror configuration.

  3. Inhibition of Viability, Proliferation, Cytokines Secretion, Surface Antigen Expression, and Adipogenic and Osteogenic Differentiation of Adipose-Derived Stem Cells by Seven-Day Exposure to 0.5 T Static Magnetic Fields

    PubMed Central

    Wang, Jian; Xiang, Bo; Deng, Jixian; Freed, Darren H.; Arora, Rakesh C.; Tian, Ganghong

    2016-01-01

    After seven-day exposure to 0.5-Tesla Static Magnetic Field (SMF), Adipose-derived Stem Cells (ASCs) and those labeled by superparamagnetic iron oxide (SPIO) nanoparticles were examined for viability by methyl thiazol tetrazolium (MTT) assay, proliferation by cell counting and bromodeoxyuridine (BrdU) incorporation, DNA integrity by single cell gel electrophoresis, surface antigen by flow cytometry analysis, and the expression of cytokines and genetic markers by reverse transcription-PCR and underwent adipogenic and osteogenic differentiation assessed by quantifying related specific genes expression. The SMF slightly reduced cell viability and proliferation and inhibited the expression of CD49d, CD54, and CD73 but did not damage DNA integrity. The SMF slightly downregulated the expression of cytokines including Vascular Endothelial Growth Factor (VEGF), Insulin-like Growth Factor-1 (IGF-1), Transforming Growth Factor Beta 1 (TGF-β1), genetic markers comprising Stem Cell Antigen-1 (Sca1), Octamer-4 (Oct-4), ATP-binding Cassette Subfamily B Member 1 (ABCB1), adipogenic marker genes containing Lipoprotein Lipase (LPL), Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ), and osteogenic marker genes including Secreted Phosphor-protein 1 (SPP1) and Osterix (OSX). Exposure to 0.5 T SMF for seven days inhibited viability, proliferation, surface antigen expression, cytokine secretion, stem cell genetic marker expression, and adipogenic and osteogenic differentiation but did not affect the DNA integrity in ASCs with or without SPIO labeling. PMID:26880984

  4. Inhibition of Viability, Proliferation, Cytokines Secretion, Surface Antigen Expression, and Adipogenic and Osteogenic Differentiation of Adipose-Derived Stem Cells by Seven-Day Exposure to 0.5 T Static Magnetic Fields.

    PubMed

    Wang, Jian; Xiang, Bo; Deng, Jixian; Freed, Darren H; Arora, Rakesh C; Tian, Ganghong

    2016-01-01

    After seven-day exposure to 0.5-Tesla Static Magnetic Field (SMF), Adipose-derived Stem Cells (ASCs) and those labeled by superparamagnetic iron oxide (SPIO) nanoparticles were examined for viability by methyl thiazol tetrazolium (MTT) assay, proliferation by cell counting and bromodeoxyuridine (BrdU) incorporation, DNA integrity by single cell gel electrophoresis, surface antigen by flow cytometry analysis, and the expression of cytokines and genetic markers by reverse transcription-PCR and underwent adipogenic and osteogenic differentiation assessed by quantifying related specific genes expression. The SMF slightly reduced cell viability and proliferation and inhibited the expression of CD49d, CD54, and CD73 but did not damage DNA integrity. The SMF slightly downregulated the expression of cytokines including Vascular Endothelial Growth Factor (VEGF), Insulin-like Growth Factor-1 (IGF-1), Transforming Growth Factor Beta 1 (TGF-β1), genetic markers comprising Stem Cell Antigen-1 (Sca1), Octamer-4 (Oct-4), ATP-binding Cassette Subfamily B Member 1 (ABCB1), adipogenic marker genes containing Lipoprotein Lipase (LPL), Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ), and osteogenic marker genes including Secreted Phosphor-protein 1 (SPP1) and Osterix (OSX). Exposure to 0.5 T SMF for seven days inhibited viability, proliferation, surface antigen expression, cytokine secretion, stem cell genetic marker expression, and adipogenic and osteogenic differentiation but did not affect the DNA integrity in ASCs with or without SPIO labeling. PMID:26880984

  5. Superconducting link bus design for the accelerator project for upgrade of LHC

    SciTech Connect

    Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.; /Fermilab

    2011-06-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

  6. Superconducting link bus design for the accelerator project for upgrade of LHC

    SciTech Connect

    Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.; /Fermilab

    2010-08-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

  7. Hadron colliders (SSC/LHC)

    SciTech Connect

    Chao, A.W.; Palmer, R.B.; Evans, L.; Gareyte, J.; Siemann, R.H.

    1992-12-31

    The nominal SSC and LHC designs should operate conservatively at luminosities up to 10{sup 33} cm{sup {minus}2} s{sup {minus}1}. This luminosity is dictated by the event rates that can be handled by the detectors. However, this limit is event dependent (e.g. it does not take much of a detector to detect the event pp {yields} elephant; all one needs is extremely high luminosity). As such, it is useful to explore the possibility of going beyond the 10{sup 33} cm{sup {minus}2} s{sup {minus}1} level. Such exploration will also improve the accelerator physics understanding of pp collider designs. If the detector limitations are removed, the first accelerator limits occur when the luminosity is at the level of 10{sup 34} cm{sup {minus}2}s{sup {minus}1}. These accelerator limits will first be reviewed. The authors will then continue on to explore even higher luminosity as the ultimate limit of pp colliders. Accelerator technologies needed to achieve this ultimate luminosity as well as the R and D needed to reach it are discussed.

  8. Modelling of helium-mediated quench propagation in the LHC prototype test string-1

    NASA Astrophysics Data System (ADS)

    Chorowski, M.; Grzegory, P.; Serio, L.; van Weelderen, R.

    2000-08-01

    The Large Hadron Collider (LHC) prototype test string-1, hereafter referred to as the string, is composed of three 10-m long prototype dipole magnets and one 6-m long prototype quadrupole magnet. The magnets are immersed in a pressurized static bath of superfluid helium that is maintained at a pressure of about 1 bar and at a temperature of about 1.9 K. This helium bath constitutes one single hydraulic unit, extending along 42.5 m of the string length. We have measured the triggering of quenches of the string magnets due to the quenching of a single dipole magnet located at the string's extremity, i.e., "quench propagation". Previously reported measurements enabled to establish that in this configuration the quench propagation is mediated by the helium and not by the inter-magnet bus bar connections [L. Coull, D. Hagedorn, G. Krainz, F. Rodriguez-Mateos, R. Schmidt, Quench propagation tests on the LHC superconducting magnet string, in: S. Myers, A. Pacheco, R. Pascual, C. Petit-Jean-Genaz, J. Poole (Eds.), Fifth European Particle Accelerator Conference - EPAC '96, Sitges, Barcelona, Spain, 10-14 June 1996, IOP, Bristol, 1996; F. Rodriguez-Mateos, R. Schmidt, L. Serio, Thermo-hydraulic quench propagation at the LHC superconducting magnet string, in: D. Dew-Hughes, R.G. Scurlock, J.H.P. Watson (Eds), 17th International Cryogenic Engineering Conference (ICEC-17), Bournemouth, UK, 14-17 July 1998, IOP, Bristol, 1998]. We present a model of helium-mediated quench propagation based on the qualitative conclusions of these two previous papers, and on additional information gained from a dedicated series of quench propagation measurements that were not previously reported. We will discuss the specific mechanisms and their main parameters involved at different timescales of the propagation process, and apply the model to make quantitative predictions.

  9. Schoolwide Literacy Days.

    ERIC Educational Resources Information Center

    Polder, Darlene D.

    2000-01-01

    Describes 10 "literacy day" activities that one California elementary school has used successfully schoolwide, typically one such day per month, to make reading fun and purposeful, while developing a sense of community. Includes: spread-a-quilt day; teacher exchange day; turn off the TV; Dr. Seuss day; community readers; schoolwide poets; original…

  10. High Energy Nuclear Physics:. From Bear Mountain to the LHC

    NASA Astrophysics Data System (ADS)

    McLerran, Larry

    2013-06-01

    I review the development of high energy nuclear physics, in particular the attempts to make new forms of matter in hadronic collisions. I begin with early experimental work done at the Bevelac, the AGS and the SPS. Early theoretical work concentrated on understanding properties of quark and gluonic matter at high temperature and density, the Quark Gluon Plama (QGP), particularly using the methods of lattice gauge theory. Recent theoretical work has involved attempts to more quantitatively describe data coming from experiments at RHIC and LHC. In addition, new forms of matter have been proposed to describe the early times in hadronic collisions. The Color Glass Condensate (CGC) is the high density gluonic matter that initially composes colliding high energy nuclei. The Glasma is highly coherent color electric and color magnetic fields radiating gluons that eventually thermalize. Methods derivative of strongly interacting gauge theory (AdSCFT Correspondence) have been employed to qualitatively understand finite temperature QCD when the intrinsic strength of interactions is strong. The RHIC and LHC experiments provide compelling experimental data to establish that the matter produced in ultra-relativistic heavy is a strongly interacting Quark Gluon Plasma (sQGP). To what degree, in my opinion, the sQGP is a thermally equilibrated Quark Gluon Plasma, or a Glasma is not yet determined...

  11. Feedback Configuration Tools for LHC Low Level RF

    SciTech Connect

    Van Winkle, D.; Fox, J.; Mastorides, T.; Rivetta, C.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /CERN

    2009-12-16

    The LHC Low Level RF System (LLRF) is a complex multi-VME crate system which is used to regulate the superconductive cavity gap voltage as well as to lower the impedance as seen by the beam through low latency feedback. This system contains multiple loops with several parameters to be set before the loops can be closed. In this paper, we present a suite of MATLAB based tools developed to perform the preliminary alignment of the RF stations and the beginnings of a closed loop model based alignment routine. We briefly introduce the RF system and in particular the base band (time domain noise based) network analyzer system built into the LHC LLRF. The main focus of this paper is the methodology of the algorithms used by the routines within the context of the overall system. Measured results are presented that validate the technique. Because the RF systems are located in a cavern 120 m underground in a location which is relatively un-accessible without beam and completely un-accessible with beam present or magnets are energized, these remotely operated tools are a necessity for the CERN LLRF team to maintain and tune their LLRF systems in a similar fashion as to what was done very successfully in PEP-II at SLAC.

  12. First Day of Life

    MedlinePlus

    ... Things to Know About Zika & Pregnancy The First Day of Life KidsHealth > For Parents > The First Day ... continue What Your Baby Does on the First Day Many parents are surprised to see how alert ...

  13. $A^t_{FB}$ Meets LHC

    SciTech Connect

    Hewett, JoAnne L.; Shelton, Jessie; Spannowsky, Michael; Tait, Tim M.P.; Takeuchi, Michihisa; /Heidelberg U.

    2012-02-14

    The recent Tevatron measurement of the forward-backward asymmetry of the top quark shows an intriguing discrepancy with Standard Model expectations, particularly at large t{bar t} invariant masses. Measurements of this quantity are subtle at the LHC, due to its pp initial state, however, one can define a forward-central-charge asymmetry which captures the physics. We study the capability of the LHC to measure this asymmetry and find that within the SM a measurement at the 5{sigma} level is possible with roughly 60 fb{sup -1} at {radical}s = 14 TeV. If nature realizes a model which enhances the asymmetry (as is necessary to explain the Tevatron measurements), a significant difference from zero can be observed much earlier, perhaps even during early LHC running at {radical}s = 7 TeV. We further explore the capabilities of the 7 TeV LHC to discover resonances or contact interactions which modify the t{bar t} invariant mass distribution using recent boosted top tagging techniques. We find that TeV-scale color octet resonances can be discovered, even with small coupling strengths and that contact interactions can be probed at scales exceeding 6 TeV. Overall, the LHC has good potential to clarify the situation with regards to the Tevatron forward-backward measurement.

  14. Status of the ALICE experiment at the LHC

    SciTech Connect

    Herrera Corral, G.

    2008-11-13

    The Large Hadron Collider will provide soon, beams of protons and collisions at high energy to the experiments. ALICE stands for A Large Ion Collider Experiment. It is one of the experiments at the Large Hadron Collider. ALICE will be dedicated to the study of heavy ion collisions. The main goal of ALICE is the observation of the transition of ordinary matter into a plasma of quarks and gluons. ALICE consists of 16 systems of detection. Two of them were designed and constructed in Mexico: i) The V0A detector, located at 3.2 mts. from the interaction point and ii) The cosmic ray detector on the top of the magnet. After a quick review of the LHC and the ALICE experiment we will focus on the description of these systems.

  15. First Beam Measurements with the LHC Synchrotron Light Monitors

    SciTech Connect

    Lefevre, Thibaut; Bravin, Enrico; Burtin, Gerard; Guerrero, Ana; Jeff, Adam; Rabiller, Aurelie; Roncarolo, Federico; Fisher, Alan; /SLAC

    2012-07-13

    The continuous monitoring of the transverse sizes of the beams in the Large Hadron Collider (LHC) relies on the use of synchrotron radiation and intensified video cameras. Depending on the beam energy, different synchrotron light sources must be used. A dedicated superconducting undulator has been built for low beam energies (450 GeV to 1.5 TeV), while edge and centre radiation from a beam-separation dipole magnet are used respectively for intermediate and high energies (up to 7 TeV). The emitted visible photons are collected using a retractable mirror, which sends the light into an optical system adapted for acquisition using intensified CCD cameras. This paper presents the design of the imaging system, and compares the expected light intensity with measurements and the calculated spatial resolution with a cross calibration performed with the wire scanners. Upgrades and future plans are also discussed.

  16. CMS tracking performance results from early LHC operation

    SciTech Connect

    Khachatryan, Vardan; et al.

    2010-11-24

    The first LHC pp collisions at centre-of-mass energies of 0.9 and 2.36 TeV were recorded by the CMS detector in December 2009. The trajectories of charged particles produced in the collisions were reconstructed using the all-silicon Tracker and their momenta were measured in the 3.8 T axial magnetic field. Results from the Tracker commissioning are presented including studies of timing, efficiency, signal-to-noise, resolution, and ionization energy. Reconstructed tracks are used to benchmark the performance in terms of track and vertex resolutions, reconstruction of decays, estimation of ionization energy loss, as well as identification of photon conversions, nuclear interactions, and heavy-flavour decays.

  17. Heavy ion physics at the LHC

    SciTech Connect

    Vogt, R.

    2004-08-15

    The ion-ion center of mass energies at the LHC will exceed that at RHIC by nearly a factor of 30, providing exciting opportunities for addressing unique physics issues in a completely new energy domain. Some highlights of this new physics domain are presented here. We briefly describe how these collisions will provide new insights into the high density, low momentum gluon content of the nucleus expected to dominate the dynamics of the early state of the system. We then discuss how the dense initial state of the nucleus affects the lifetime and temperature of the produced system. Finally, we explain how the high energy domain of the LHC allows abundant production of ''rare'' processes, hard probes calculable in perturbative quantum chromodynamics, QCD. At the LHC, high momentum jets and b{bar b} bound states, the {Upsilon} family, will be produced with high statistics for the first time in heavy ion collisions.

  18. Critical services in the LHC computing

    NASA Astrophysics Data System (ADS)

    Sciabà, A.

    2010-04-01

    The LHC experiments (ALICE, ATLAS, CMS and LHCb) rely for the data acquisition, processing, distribution, analysis and simulation on complex computing systems, running using a variety of services, provided by the experiments, the Worldwide LHC Computing Grid and the different computing centres. These services range from the most basic (network, batch systems, file systems) to the mass storage services or the Grid information system, up to the different workload management systems, data catalogues and data transfer tools, often internally developed in the collaborations. In this contribution we review the status of the services most critical to the experiments by quantitatively measuring their readiness with respect to the start of the LHC operations. Shortcomings are identified and common recommendations are offered.

  19. Machine optics studies for the LHC measurements

    NASA Astrophysics Data System (ADS)

    Trzebiński, Maciej

    2014-11-01

    In this work the properties of scattered protons in the vicinity of the ATLAS Interaction Point (IP1) for various LHC optics settings are discussed. Firstly, the beam elements installed around IP1 are presented. Then the ATLAS forward detector systems: Absolute Luminosity For ATLAS (ALFA) and ATLAS Forward Protons (AFP) are described and their similarities and differences are discussed. Next, the various optics used at Large Hadron Collider (LHC) are described and the beam divergence and width at the Interaction Point as well as at the ATLAS forward detectors locations are calculated. Finally, the geometric acceptance of the ATLAS forward detectors is shown and the impact of the LHC collimators on it is discussed.

  20. Higgs coupling measurements at the LHC

    NASA Astrophysics Data System (ADS)

    Englert, Christoph; Kogler, Roman; Schulz, Holger; Spannowsky, Michael

    2016-07-01

    Due to the absence of tantalising hints for new physics during the LHC's Run 1, the extension of the Higgs sector by dimension-six operators will provide the new phenomenological standard for searches of non-resonant extensions of the Standard Model. Using all dominant and subdominant Higgs production mechanisms at the LHC, we compute the constraints on Higgs physics-relevant dimension-six operators in a global and correlated fit. We show in how far these constraints can be improved by new Higgs channels becoming accessible at higher energy and luminosity, both through inclusive cross sections as well as through highly sensitive differential distributions. This allows us to discuss the sensitivity to new effects in the Higgs sector that can be reached at the LHC if direct hints for physics beyond the SM remain elusive. We discuss the impact of these constraints on well-motivated BSM scenarios.

  1. LHC RF System Time-Domain Simulation

    SciTech Connect

    Mastorides, T.; Rivetta, C.; /SLAC

    2010-09-14

    Non-linear time-domain simulations have been developed for the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC). These simulations capture the dynamic behavior of the RF station-beam interaction and are structured to reproduce the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They are also a valuable tool for the study of diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Results from these studies and related measurements from PEP-II and LHC have been presented in multiple places. This report presents an example of the time-domain simulation implementation for the LHC.

  2. New Physics Undercover at the LHC

    NASA Astrophysics Data System (ADS)

    Lou, Hou Keong

    With the completion of 7 TeV and 8 TeV data taking at the Large Hadron Collider (LHC), the physics community witnessed one of the great triumphs of modern physics: the completion of the Standard Model (SM) as an effective theory. The final missing particle, the Higgs boson, was observed and its mass was measured. However, many theoretical questions remain unanswered. What is the source of electroweak symmetry breaking? What is the nature of dark matter? How does gravity fit into the picture? With no definitive hints of new physics at the LHC, we must consider the possibility that our search strategies need to be expanded. Conventional LHC searches focus on theoretically motivated scenarios, such as the Minimal Supersymmetric Standard Models and Little Higgs Theories. However, it is possible that new physics may be entirely different from what we might expect. In this thesis, we examine a variety of scenarios that lead to new physics undercover at the LHC. First we look at potential new physics hiding in Quantum Chromo-Dynamics backgrounds, which may be uncovered using jet substructure techniques in a data-driven way. Then we turn to new long-lived particles hiding in Higgs decay, which may lead to displaced vertices. Such a signal can be unearthed through a data-driven analysis. Then we turn to new physics with ``semi-visible jets'', which lead to missing momentum aligned with jet momentum. These events are vetoed in traditional searches and we demonstrate ways to uncover these signals. Lastly, we explore performance of future colliders in two case studies: Stops and Higgs Portal searches. We show that a 100 TeV collider will lead to significant improvements over 14 TeV LHC runs. Indeed, new physics may lie undercover at the LHC and future colliders, waiting to be discovered.

  3. Adult Day Services

    MedlinePlus

    A Smart Choice Adult Day Services Comparison At-a-Glance 1 Adult Day Services Assisted Living Home Care Nursing Homes Live at home with family ... supervision Nursing care available as needed during the day Flexibility to receive care only on days when ...

  4. Family Day Care Associations.

    ERIC Educational Resources Information Center

    Bookman, Robert

    This paper presents information on the organization and accomplishments of Family Day Care Associations, organized groups of individuals who provide day care services in their own homes. Although primarily based on experiences of day care mothers in New York State, the paper presents information relevant to day care providers in any area.…

  5. Particle Physics on the Eve of Lhc

    NASA Astrophysics Data System (ADS)

    Studenikin, Alexander I.

    2009-01-01

    Fundamentals of particle physics. The quantum number of color, colored quarks and dynamic models of Hadrons composed of quasifree quarks / V. Matveev, A. Tavkhelidze. Discovery of the color degree of freedom in particle physics: a personal perspective / O. W. Greenberg. The evolution of the concepts of energy, momentum, and mass from Newton and Lomonosov to Einstein and Feynman / L. Okun -- Physics at accelerators and studies in SM and beyond. Search for new physics at LHC (CMS) / N. Krasnikov. Measuring the Higgs Boson(s) at ATLAS / C. Kourkoumelis. Beyond the standard model physics reach of the ATLAS experiment / G. Unel. The status of the International Linear Collider / B. Foster. Review of results of the electron-proton collider HERA / V. Chekelian. Recent results from the Tevatron on CKM matrix elements from Bs oscillations and single top production, and studies of CP violation in Bs Decays / J. P. Fernández. Direct observation of the strange b Barion [symbol] / L. Vertogradov. Search for new physics in rare B Decays at LHCb / V. Egorychev. CKM angle measurements at LHCb / S. Barsuk. Collider searches for extra spatial dimensions and black holes / G. Landsberg -- Neutrino Physics. Results of the MiniBooNE neutrino oscillation experiment / Z. Djurcic. MINOS results and prospects / J. P. Ochoa-Ricoux. The new result of the neutrino magnetic moment measurement in the GEMMA experiment / A. G. Beda ... [et al.]. The Baikal neutrino experiment: status, selected physics results, and perspectives / V. Aynutdinov ... [et al.]. Neutrino telescopes in the deep sea / V. Flaminio. Double beta decay: present status / A. S. Barabash. Beta-beams / C. Volpe. T2K experiment / K. Sakashita. Non-standard neutrino physics probed by Tokai-to-Kamioka-Korea two-detector complex / N. Cipriano Ribeiro ... [et al.]. Sterile neutrinos: from cosmology to the LHC / F. Vannucci. From Cuoricino to Cuore towards the inverted hierarchy region / C. Nones. The MARE experiment: calorimetric

  6. Bigger, Better, Faster, More at the LHC

    SciTech Connect

    Izaguirre, Eder; Manhart, Michael; Wacker, Jay G.; /SLAC

    2010-08-26

    Multijet plus missing energy searches provide universal coverage for theories that have new colored particles that decay into a dark matter candidate and jets. These signals appear at the LHC further out on the missing energy tail than two-to-two scattering indicates. The simplicity of the searches at the LHC contrasts sharply with the Tevatron where more elaborate searches are necessary to separate signal from background. The searches presented in this article effectively distinguish signal from background for any theory where the LSP is a daughter or granddaughter of the pair-produced colored parent particle without ever having to consider missing energies less than 400 GeV.

  7. Production of hhjj at the LHC.

    PubMed

    Dolan, Matthew J; Englert, Christoph; Greiner, Nicolas; Spannowsky, Michael

    2014-03-14

    Until now, a phenomenologically complete analysis of the hh+2j channel at the LHC has been missing. This is mostly due to the high complexity of the involved one-loop gluon fusion contribution and the fact that a reliable estimate thereof cannot be obtained through simplified calculations in the mt→∞ limit. In this Letter, we report on the LHC's potential to access di-Higgs production in association with two jets in a fully showered hadron-level analysis. Our study includes the finite top and bottom mass dependencies for the gluon fusion contribution. PMID:24679280

  8. R-axion detection at LHC

    SciTech Connect

    Goh, Hock-Seng; Ibe, Masahiro; /SLAC

    2009-06-19

    Supersymmetric models with spontaneously broken approximate R-symmetry contains a light spin 0 particle, the R-axion. The properties of the particle can be a powerful probe of the structure of the new physics. In this paper, we discuss the possibilities of the R-axion detection at the LHC experiments. It is challenge to observe this light particle in the LHC environment. However, for typical values in which the mass of the R-axion is a few hundred MeV, we show that those particles can be detected by searching for displaced vertices from R-axion decay.

  9. Lessons from LHC elastic and diffractive data

    SciTech Connect

    Martin, A.D.; Khoze, V.A.; Ryskin, M.G.

    2015-04-10

    In the light of LHC data, we discuss the global description of all high-energy elastic and diffractive data, using a one-pomeron model, but including multi-pomeron interactions. The LHC data indicate the need of a k{sub t}(s) behaviour, where k{sub t} is the gluon transverse momentum along the partonic ladder structure which describes the pomeron. We also discuss tensions in the data, as well as the t dependence of the slope of dσ{sub el}/dt in the small t domain.

  10. Charged-particle multiplicity at LHC energies

    ScienceCinema

    None

    2011-10-06

    The talk presents the measurement of the pseudorapidity density and the multiplicity distribution with ALICE at the achieved LHC energies of 0.9 and 2.36 TeV.An overview about multiplicity measurements prior to LHC is given and the related theoretical concepts are briefly discussed.The analysis procedure is presented and the systematic uncertainties are detailed. The applied acceptance corrections and the treatment of diffraction are discussed.The results are compared with model predictions. The validity of KNO scaling in restricted phase space regions is revisited. 

  11. LHC: The Emptiest Space in the Solar System

    ERIC Educational Resources Information Center

    Cid-Vidal, Xabier; Cid, Ramon

    2011-01-01

    Proton beams have been colliding at 7 TeV in the Large Hadron Collider (LHC) since 30 March 2010, meaning that the LHC research programme is underway. Particle physicists around the world are looking forward to using the data from these collisions, as the LHC is running at an energy three and a half times higher than previously achieved at any…

  12. Study of the Variation of Transverse Voltage in the 4 Rod Crab Cavity for LHC

    SciTech Connect

    B. Hall, G. Burt, C. Lingwood, R. Rimmer, H. Wang

    2011-04-01

    The planned high luminosity upgrade to LHC will utilise crab cavities to rotate the beam in order to increase the luminosity in the presence of a finite crossing angle. A compact design is required in order for the cavities to fit between opposing beam-lines. In this paper we discuss we discuss one option for the LHC crab cavity based on a 4 rod TEM deflecting cavity. Due to the large transverse size of the LHC beam the cavity is required to have a large aperture while maintaining a constant transverse voltage across the aperture. The cavity has been optimised to minimise the variation of the transverse voltage while keeping the peak surface electric and magnetic fields low for a given kick. This is achieved while fitting within the strict design space of the LHC. The variation of deflecting voltage across the aperture has been studied numerically and compared with numerical and analytical estimates of other deflecting cavity types. Performance measurements an aluminium prototype of this cavity are presented and compared to the simulated design.

  13. Final Design and Experimental Validation of the Thermal Performance of the LHC Lattice Cryostats

    NASA Astrophysics Data System (ADS)

    Bourcey, N.; Capatina, O.; Parma, V.; Poncet, A.; Rohmig, P.; Serio, L.; Skoczen, B.; Tock, J.-P.; Williams, L. R.

    2004-06-01

    The recent commissioning and operation of the LHC String 2 have given a first experimental validation of the global thermal performance of the LHC lattice cryostat at nominal cryogenic conditions. The cryostat designed to minimize the heat inleak from ambient temperature, houses under vacuum and thermally protects the cold mass, which contains the LHC twin-aperture superconducting magnets operating at 1.9 K in superfluid helium. Mechanical components linking the cold mass to the vacuum vessel, such as support posts and insulation vacuum barriers are designed with efficient thermalisations for heat interception to minimise heat conduction. Heat inleak by radiation is reduced by employing multilayer insulation (MLI) wrapped around the cold mass and around an aluminium thermal shield cooled to about 60 K. Measurements of the total helium vaporization rate in String 2 gives, after substraction of supplementary heat loads and end effects, an estimate of the total thermal load to a standard LHC cell (107 m) including two Short Straight Sections and six dipole cryomagnets. Temperature sensors installed at critical locations provide a temperature mapping which allows validation of the calculated and estimated thermal performance of the cryostat components, including efficiency of the heat interceptions.

  14. The LHC's Next Big Mystery

    ERIC Educational Resources Information Center

    Lincoln, Don

    2015-01-01

    When the sun rose over America on July 4, 2012, the world of science had radically changed. The Higgs boson had been discovered. Mind you, the press releases were more cautious than that, with "a new particle consistent with being the Higgs boson" being the carefully constructed phrase of the day. But, make no mistake, champagne corks…

  15. Particle Physics on the Eve of Lhc

    NASA Astrophysics Data System (ADS)

    Studenikin, Alexander I.

    2009-01-01

    Fundamentals of particle physics. The quantum number of color, colored quarks and dynamic models of Hadrons composed of quasifree quarks / V. Matveev, A. Tavkhelidze. Discovery of the color degree of freedom in particle physics: a personal perspective / O. W. Greenberg. The evolution of the concepts of energy, momentum, and mass from Newton and Lomonosov to Einstein and Feynman / L. Okun -- Physics at accelerators and studies in SM and beyond. Search for new physics at LHC (CMS) / N. Krasnikov. Measuring the Higgs Boson(s) at ATLAS / C. Kourkoumelis. Beyond the standard model physics reach of the ATLAS experiment / G. Unel. The status of the International Linear Collider / B. Foster. Review of results of the electron-proton collider HERA / V. Chekelian. Recent results from the Tevatron on CKM matrix elements from Bs oscillations and single top production, and studies of CP violation in Bs Decays / J. P. Fernández. Direct observation of the strange b Barion [symbol] / L. Vertogradov. Search for new physics in rare B Decays at LHCb / V. Egorychev. CKM angle measurements at LHCb / S. Barsuk. Collider searches for extra spatial dimensions and black holes / G. Landsberg -- Neutrino Physics. Results of the MiniBooNE neutrino oscillation experiment / Z. Djurcic. MINOS results and prospects / J. P. Ochoa-Ricoux. The new result of the neutrino magnetic moment measurement in the GEMMA experiment / A. G. Beda ... [et al.]. The Baikal neutrino experiment: status, selected physics results, and perspectives / V. Aynutdinov ... [et al.]. Neutrino telescopes in the deep sea / V. Flaminio. Double beta decay: present status / A. S. Barabash. Beta-beams / C. Volpe. T2K experiment / K. Sakashita. Non-standard neutrino physics probed by Tokai-to-Kamioka-Korea two-detector complex / N. Cipriano Ribeiro ... [et al.]. Sterile neutrinos: from cosmology to the LHC / F. Vannucci. From Cuoricino to Cuore towards the inverted hierarchy region / C. Nones. The MARE experiment: calorimetric

  16. Final report on the Controlled Cold Helium Spill Test in the LHC tunnel at CERN

    NASA Astrophysics Data System (ADS)

    Dufay-Chanat, L.; Bremer, J.; Casas-Cubillos, J.; Chorowski, M.; Grabowski, M.; Jedrusyna, A.; Lindell, G.; Nonis, M.; Koettig, T.; Vauthier, N.; van Weelderen, R.; Winkler, T.

    2015-12-01

    The 27 km circumference LHC underground tunnel is a space in which the helium cooled LHC magnets are installed. The vacuum enclosures of the superconducting magnets are protected by over-pressure safety relief devices that open whenever cold helium escapes either from the magnet cold enclosure or from the helium supply headers, into this vacuum enclosure. A 3-m long no stay zone around these devices is defined based on scale model studies, protecting the personnel against cold burns or asphyxia caused by such a helium release event. Recently, several simulation studies have been carried out modelling the propagation of the helium/air mixture, resulting from the opening of such a safety device, along the tunnel. The released helium flows vary in the range between 1 kg/s and 0.1 kg/s. To validate these different simulation studies, real life mock-up tests have been performed inside the LHC tunnel, releasing helium flow rates of 1 kg/s, 0.3 kg/s and 0.1 kg/s. For each test, up to 1000 liters of liquid helium were released under standard operational tunnel conditions. The data recorded include oxygen concentration, temperature and flow speed measurements, and video footage used to assess qualitatively the visibility. These measurements have been made in the up- and downstream directions, with respect to the air ventilation flow, of the spill point. This paper presents the experimental set-up under which these release tests were made, the effects of these releases on the atmospheric tunnel condition as a function of the release flow rate. We discuss the modification to the personnel access conditions to the LHC tunnel that are presently implemented as a result of these tests.

  17. Comparison of Carbon and Hi-Z Primary Collimators for the LHC Phase II Collimation System

    SciTech Connect

    Keller, Lewis; Markiewicz, Thomas; Smith, Jeffrey; Assmann, Ralph; Bracco, Chiara; Weiler, Thomas; /Karlsruhe, Inst. Technol.

    2011-10-31

    A current issue with the LHC collimation system is single-diffractive, off-energy protons from the primary collimators that pass completely through the secondary collimation system and are absorbed immediately downbeam in the cold magnets of the dispersion suppressor section. Simulations suggest that the high impact rate could result in quenching of these magnets. We have studied replacing the 60 cm primary graphite collimators, which remove halo mainly by inelastic strong interactions, with 5.25 mm tungsten, which remove halo mainly by multiple coulomb scattering and thereby reduce the rate of single-diffractive interactions that cause losses in the dispersion suppressor.

  18. The Tsallis distribution at the LHC: Phenomenology

    SciTech Connect

    Cleymans, J.

    2014-11-11

    An overview is presented of transverse momentum distributions of particles at the LHC using the Tsallis distribution. The use of a thermodynamically consistent form of this distribution leads to an excellent description of charged and identified particles. The values of the Tsallis parameter q are truly remarkably consistent.

  19. Exploring the Pomeron structure at the LHC

    NASA Astrophysics Data System (ADS)

    Royon, Christophe; Saimpert, Matthias

    2015-03-01

    We present some physics topics that will allow us to constrain the Pomeron structure at the LHC in terms of gluon and quark densities using the dijet and γ+jet events and tagged protons in AFP (ATLAS) and CMS-TOTEM. We also discuss the possibility to test the BFKL dynamics using jet-gap-jet events.

  20. LHC Phenomenology and Lattice Strong Dynamics

    NASA Astrophysics Data System (ADS)

    Fleming, G. T.

    2013-03-01

    While the LHC experimentalists work to find evidence of physics beyond the standard model, lattice gauge theorists are working as well to characterize the range of possible phenomena in strongly-coupled models of electroweak symmetry breaking. I will summarize the current progress of the Lattice Strong Dynamics (LSD) collaboration on the flavor dependence of SU(3) gauge theories.

  1. The LHCb Detector at the LHC

    NASA Astrophysics Data System (ADS)

    LHCb Collaboration; Alves, A. Augusto, Jr.; Filho, L. M. Andrade; Barbosa, A. F.; Bediaga, I.; Cernicchiaro, G.; Guerrer, G.; Lima, H. P., Jr.; Machado, A. A.; Magnin, J.; Marujo, F.; de Miranda, J. M.; Reis, A.; Santos, A.; Toledo, A.; Akiba, K.; Amato, S.; de Paula, B.; de Paula, L.; da Silva, T.; Gandelman, M.; Lopes, J. H.; Maréchal, B.; Moraes, D.; Polycarpo, E.; Rodrigues, F.; Ballansat, J.; Bastian, Y.; Boget, D.; DeBonis, I.; Coco, V.; David, P. Y.; Decamp, D.; Delebecque, P.; Drancourt, C.; Dumont-Dayot, N.; Girard, C.; Lieunard, B.; Minard, M. N.; Pietrzyk, B.; Rambure, T.; Rospabe, G.; T'Jampens, S.; Ajaltouni, Z.; Bohner, G.; Bonnefoy, R.; Borras, D.; Carloganu, C.; Chanal, H.; Conte, E.; Cornat, R.; Crouau, M.; Delage, E.; Deschamps, O.; Henrard, P.; Jacquet, P.; Lacan, C.; Laubser, J.; Lecoq, J.; Lefèvre, R.; Magne, M.; Martemiyanov, M.; Mercier, M.-L.; Monteil, S.; Niess, V.; Perret, P.; Reinmuth, G.; Robert, A.; Suchorski, S.; Arnaud, K.; Aslanides, E.; Babel, J.; Benchouk, C.; Cachemiche, J.-P.; Cogan, J.; Derue, F.; Dinkespiler, B.; Duval, P.-Y.; Garonne, V.; Favard, S.; LeGac, R.; Leon, F.; Leroy, O.; Liotard, P.-L.; Marin, F.; Menouni, M.; Ollive, P.; Poss, S.; Roche, A.; Sapunov, M.; Tocco, L.; Viaud, B.; Tsaregorodtsev, A.; Amhis, Y.; Barrand, G.; Barsuk, S.; Beigbeder, C.; Beneyton, R.; Breton, D.; Callot, O.; Charlet, D.; D'Almagne, B.; Duarte, O.; Fulda-Quenzer, F.; Jacholkowska, A.; Jean-Marie, B.; Lefrancois, J.; Machefert, F.; Robbe, P.; Schune, M.-H.; Tocut, V.; Videau, I.; Benayoun, M.; David, P.; DelBuono, L.; Gilles, G.; Domke, M.; Futterschneider, H.; Ilgner, Ch; Kapusta, P.; Kolander, M.; Krause, R.; Lieng, M.; Nedos, M.; Rudloff, K.; Schleich, S.; Schwierz, R.; Spaan, B.; Wacker, K.; Warda, K.; Agari, M.; Bauer, C.; Baumeister, D.; Bulian, N.; Fuchs, H. P.; Fallot-Burghardt, W.; Glebe, T.; Hofmann, W.; Knöpfle, K. T.; Löchner, S.; Ludwig, A.; Maciuc, F.; Sanchez Nieto, F.; Schmelling, M.; Schwingenheuer, B.; Sexauer, E.; Smale, N. J.; Trunk, U.; Voss, H.; Albrecht, J.; Bachmann, S.; Blouw, J.; Deissenroth, M.; Deppe, H.; Dreis, H. B.; Eisele, F.; Haas, T.; Hansmann-Menzemer, S.; Hennenberger, S.; Knopf, J.; Moch, M.; Perieanu, A.; Rabenecker, S.; Rausch, A.; Rummel, C.; Rusnyak, R.; Schiller, M.; Stange, U.; Uwer, U.; Walter, M.; Ziegler, R.; Avoni, G.; Balbi, G.; Bonifazi, F.; Bortolotti, D.; Carbone, A.; D'Antone, I.; Galli, D.; Gregori, D.; Lax, I.; Marconi, U.; Peco, G.; Vagnoni, V.; Valenti, G.; Vecchi, S.; Bonivento, W.; Cardini, A.; Cadeddu, S.; DeLeo, V.; Deplano, C.; Furcas, S.; Lai, A.; Oldeman, R.; Raspino, D.; Saitta, B.; Serra, N.; Baldini, W.; Brusa, S.; Chiozzi, S.; Cotta Ramusino, A.; Evangelisti, F.; Franconieri, A.; Germani, S.; Gianoli, A.; Guoming, L.; Landi, L.; Malaguti, R.; Padoan, C.; Pennini, C.; Savriè, M.; Squerzanti, S.; Zhao, T.; Zhu, M.; Bizzeti, A.; Graziani, G.; Lenti, M.; Lenzi, M.; Maletta, F.; Pennazzi, S.; Passaleva, G.; Veltri, M.; Alfonsi, M.; Anelli, M.; Balla, A.; Battisti, A.; Bencivenni, G.; Campana, P.; Carletti, M.; Ciambrone, P.; Corradi, G.; Dané, E.; Di Virgilio, A.; DeSimone, P.; Felici, G.; Forti, C.; Gatta, M.; Lanfranchi, G.; Murtas, F.; Pistilli, M.; Poli Lener, M.; Rosellini, R.; Santoni, M.; Saputi, A.; Sarti, A.; Sciubba, A.; Zossi, A.; Ameri, M.; Cuneo, S.; Fontanelli, F.; Gracco, V.; Miní, G.; Parodi, M.; Petrolini, A.; Sannino, M.; Vinci, A.; Alemi, M.; Arnaboldi, C.; Bellunato, T.; Calvi, M.; Chignoli, F.; DeLucia, A.; Galotta, G.; Mazza, R.; Matteuzzi, C.; Musy, M.; Negri, P.; Perego, D.; Pessina, G.; Auriemma, G.; Bocci, V.; Buccheri, A.; Chiodi, G.; Di Marco, S.; Iacoangeli, F.; Martellotti, G.; Nobrega, R.; Pelosi, A.; Penso, G.; Pinci, D.; Rinaldi, W.; Rossi, A.; Santacesaria, R.; Satriano, C.; Carboni, G.; Iannilli, M.; Massafferri Rodrigues, A.; Messi, R.; Paoluzzi, G.; Sabatino, G.; Santovetti, E.; Satta, A.; Amoraal, J.; van Apeldoorn, G.; Arink, R.; van Bakel, N.; Band, H.; Bauer, Th; Berkien, A.; van Beuzekom, M.; Bos, E.; Bron, Ch; Ceelie, L.; Doets, M.; van der Eijk, R.; Fransen, J.-P.; de Groen, P.; Gromov, V.; Hierck, R.; Homma, J.; Hommels, B.; Hoogland, W.; Jans, E.; Jansen, F.; Jansen, L.; Jaspers, M.; Kaan, B.; Koene, B.; Koopstra, J.; Kroes, F.; Kraan, M.; Langedijk, J.; Merk, M.; Mos, S.; Munneke, B.; Palacios, J.; Papadelis, A.; Pellegrino, A.; van Petten, O.; du Pree, T.; Roeland, E.; Ruckstuhl, W.; Schimmel, A.; Schuijlenburg, H.; Sluijk, T.; Spelt, J.; Stolte, J.; Terrier, H.; Tuning, N.; Van Lysebetten, A.; Vankov, P.; Verkooijen, J.; Verlaat, B.; Vink, W.; de Vries, H.; Wiggers, L.; Ybeles Smit, G.; Zaitsev, N.; Zupan, M.; Zwart, A.; van den Brand, J.; Bulten, H. J.; de Jong, M.; Ketel, T.; Klous, S.; Kos, J.; M'charek, B.; Mul, F.; Raven, G.; Simioni, E.; Cheng, J.; Dai, G.; Deng, Z.; Gao, Y.; Gong, G.; Gong, H.; He, J.; Hou, L.; Li, J.; Qian, W.; Shao, B.; Xue, T.; Yang, Z.; Zeng, M.; Muryn, B.; Ciba, K.; Oblakowska-Mucha, A.; Blocki, J.; Galuszka, K.; Hajduk, L.; Michalowski, J.; Natkaniec, Z.; Polok, G.; Stodulski, M.; Witek, M.; Brzozowski, K.; Chlopik, A.; Gawor, P.; Guzik, Z.; Nawrot, A.; Srednicki, A.; Syryczynski, K.; Szczekowski, M.; Anghel, D. V.; Cimpean, A.; Coca, C.; Constantin, F.; Cristian, P.; Dumitru, D. D.; Dumitru, D. T.; Giolu, G.; Kusko, C.; Magureanu, C.; Mihon, Gh; Orlandea, M.; Pavel, C.; Petrescu, R.; Popescu, S.; Preda, T.; Rosca, A.; Rusu, V. L.; Stoica, R.; Stoica, S.; Tarta, P. D.; Filippov, S.; Gavrilov, Yu; Golyshkin, L.; Gushchin, E.; Karavichev, O.; Klubakov, V.; Kravchuk, L.; Kutuzov, V.; Laptev, S.; Popov, S.; Aref'ev, A.; Bobchenko, B.; Dolgoshein, V.; Egorychev, V.; Golutvin, A.; Gushchin, O.; Konoplyannikov, A.; Korolko, I.; Kvaratskheliya, T.; Machikhiliyan, I.; Malyshev, S.; Mayatskaya, E.; Prokudin, M.; Rusinov, D.; Rusinov, V.; Shatalov, P.; Shchutska, L.; Tarkovskiy, E.; Tayduganov, A.; Voronchev, K.; Zhiryakova, O.; Bobrov, A.; Bondar, A.; Eidelman, S.; Kozlinsky, A.; Shekhtman, L.; Beloous, K. S.; Dzhelyadin, R. I.; Gelitsky, Yu V.; Gouz, Yu P.; Kachnov, K. G.; Kobelev, A. S.; Matveev, V. D.; Novikov, V. P.; Obraztsov, V. F.; Ostankov, A. P.; Romanovsky, V. I.; Rykalin, V. I.; Soldatov, A. P.; Soldatov, M. M.; Tchernov, E. N.; Yushchenko, O. P.; Bochin, B.; Bondar, N.; Fedorov, O.; Golovtsov, V.; Guets, S.; Kashchuk, A.; Lazarev, V.; Maev, O.; Neustroev, P.; Sagidova, N.; Spiridenkov, E.; Volkov, S.; Vorobyev, An; Vorobyov, A.; Aguilo, E.; Bota, S.; Calvo, M.; Comerma, A.; Cano, X.; Dieguez, A.; Herms, A.; Lopez, E.; Luengo, S.; Garra, J.; Garrido, Ll; Gascon, D.; Gaspar de Valenzuela, A.; Gonzalez, C.; Graciani, R.; Grauges, E.; Perez Calero, A.; Picatoste, E.; Riera, J.; Rosello, M.; Ruiz, H.; Vilasis, X.; Xirgu, X.; Adeva, B.; Cid Vidal, X.; MartÉnez Santos, D.; Esperante Pereira, D.; Fungueiriño Pazos, J. L.; Gallas Torreira, A.; Gómez, C. Lois; Pazos Alvarez, A.; Pérez Trigo, E.; Pló Casasús, M.; Rodriguez Cobo, C.; Rodríguez Pérez, P.; Saborido, J. J.; Seco, M.; Vazquez Regueiro, P.; Bartalini, P.; Bay, A.; Bettler, M.-O.; Blanc, F.; Borel, J.; Carron, B.; Currat, C.; Conti, G.; Dormond, O.; Ermoline, Y.; Fauland, P.; Fernandez, L.; Frei, R.; Gagliardi, G.; Gueissaz, N.; Haefeli, G.; Hicheur, A.; Jacoby, C.; Jalocha, P.; Jimenez-Otero, S.; Hertig, J.-P.; Knecht, M.; Legger, F.; Locatelli, L.; Moser, J.-R.; Needham, M.; Nicolas, L.; Perrin-Giacomin, A.; Perroud, J.-P.; Potterat, C.; Ronga, F.; Schneider, O.; Schietinger, T.; Steele, D.; Studer, L.; Tareb, M.; Tran, M. T.; van Hunen, J.; Vervink, K.; Villa, S.; Zwahlen, N.; Bernet, R.; Büchler, A.; Gassner, J.; Lehner, F.; Sakhelashvili, T.; Salzmann, C.; Sievers, P.; Steiner, S.; Steinkamp, O.; Straumann, U.; van Tilburg, J.; Vollhardt, A.; Volyanskyy, D.; Ziegler, M.; Dovbnya, A.; Ranyuk, Yu; Shapoval, I.; Borisova, M.; Iakovenko, V.; Kyva, V.; Kovalchuk, O.; Okhrimenko, O.; Pugatch, V.; Pylypchenko, Yu; Adinolfi, M.; Brook, N. H.; Head, R. D.; Imong, J. P.; Lessnoff, K. A.; Metlica, F. C. D.; Muir, A. J.; Rademacker, J. H.; Solomin, A.; Szczypka, P. M.; Barham, C.; Buszello, C.; Dickens, J.; Gibson, V.; Haines, S.; Harrison, K.; Jones, C. R.; Katvars, S.; Kerzel, U.; Lazzeroni, C.; Li, Y. Y.; Rogers, G.; Storey, J.; Skottowe, H.; Wotton, S. A.; Adye, T. J.; Densham, C. J.; Easo, S.; Franek, B.; Loveridge, P.; Morrow, D.; Morris, J. V.; Nandakumar, R.; Nardulli, J.; Papanestis, A.; Patrick, G. N.; Ricciardi, S.; Woodward, M. L.; Zhang, Z.; Chamonal, R. J. U.; Clark, P. J.; Clarke, P.; Eisenhardt, S.; Gilardi, N.; Khan, A.; Kim, Y. M.; Lambert, R.; Lawrence, J.; Main, A.; McCarron, J.; Mclean, C.; Muheim, F.; Osorio-Oliveros, A. F.; Playfer, S.; Styles, N.; Xie, Y.; Bates, A.; Carson, L.; da Cunha Marinho, F.; Doherty, F.; Eklund, L.; Gersabeck, M.; Haddad, L.; Macgregor, A. A.; Melone, J.; McEwan, F.; Petrie, D. M.; Paterson, S. K.; Parkes, C.; Pickford, A.; Rakotomiaramanana, B.; Rodrigues, E.; Saavedra, A. F.; Soler, F. J. P.; Szumlak, T.; Viret, S.; Allebone, L.; Awunor, O.; Back, J.; Barber, G.; Barnes, C.; Cameron, B.; Clark, D.; Clark, I.; Dornan, P.; Duane, A.; Eames, C.; Egede, U.; Girone, M.; Greenwood, S.; Hallam, R.; Hare, R.; Howard, A.; Jolly, S.; Kasey, V.; Khaleeq, M.; Koppenburg, P.; Miller, D.; Plackett, R.; Price, D.; Reece, W.; Savage, P.; Savidge, T.; Simmons, B.; Vidal-Sitjes, G.; Websdale, D.; Affolder, A.; Anderson, J. S.; Biagi, S. F.; Bowcock, T. J. V.; Carroll, J. L.; Casse, G.; Cooke, P.; Donleavy, S.; Dwyer, L.; Hennessy, K.; Huse, T.; Hutchcroft, D.; Jones, D.; Lockwood, M.; McCubbin, M.; McNulty, R.; Muskett, D.; Noor, A.; Patel, G. D.; Rinnert, K.; Shears, T.; Smith, N. A.; Southern, G.; Stavitski, I.; Sutcliffe, P.; Tobin, M.; Traynor, S. M.; Turner, P.; Whitley, M.; Wormald, M.; Wright, V.; Bibby, J. H.; Brisbane, S.; Brock, M.; Charles, M.; Cioffi, C.; Gligorov, V. V.; Handford, T.; Harnew, N.; Harris, F.; John, M. J. J.; Jones, M.; Libby, J.; Martin, L.; McArthur, I. A.; Muresan, R.; Newby, C.; Ottewell, B.; Powell, A.; Rotolo, N.; Senanayake, R. S.; Somerville, L.; Soroko, A.; Spradlin, P.; Sullivan, P.; Stokes-Rees, I.; Topp-Jorgensen, S.; Xing, F.; Wilkinson, G.; Artuso, M.; Belyaev, I.; Blusk, S.; Lefeuvre, G.; Menaa, N.; Menaa-Sia, R.; Mountain, R.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Abadie, L.; Aglieri-Rinella, G.; Albrecht, E.; André, J.; Anelli, G.; Arnaud, N.; Augustinus, A.; Bal, F.; Barandela Pazos, M. C.; Barczyk, A.; Bargiotti, M.; Batista Lopes, J.; Behrendt, O.; Berni, S.; Binko, P.; Bobillier, V.; Braem, A.; Brarda, L.; Buytaert, J.; Camilleri, L.; Cambpell, M.; Castellani, G.; Cataneo, F.; Cattaneo, M.; Chadaj, B.; Charpentier, P.; Cherukuwada, S.; Chesi, E.; Christiansen, J.; Chytracek, R.; Clemencic, M.; Closier, J.; Collins, P.; Colrain, P.; Cooke, O.; Corajod, B.; Corti, G.; D'Ambrosio, C.; Damodaran, B.; David, C.; de Capua, S.; Decreuse, G.; Degaudenzi, H.; Dijkstra, H.; Droulez, J.-P.; Duarte Ramos, D.; Dufey, J. P.; Dumps, R.; Eckstein, D.; Ferro-Luzzi, M.; Fiedler, F.; Filthaut, F.; Flegel, W.; Forty, R.; Fournier, C.; Frank, M.; Frei, C.; Gaidioz, B.; Gaspar, C.; Gayde, J.-C.; Gavillet, P.; Go, A.; Gracia Abril, G.; Graulich, J.-S.; Giudici, P.-A.; Guirao Elias, A.; Guglielmini, P.; Gys, T.; Hahn, F.; Haider, S.; Harvey, J.; Hay, B.; Hernando Morata, J.-A.; Herranz Alvarez, J.; van Herwijnen, E.; Hilke, H. J.; von Holtey, G.; Hulsbergen, W.; Jacobsson, R.; Jamet, O.; Joram, C.; Jost, B.; Kanaya, N.; Knaster Refolio, J.; Koestner, S.; Koratzinos, M.; Kristic, R.; Lacarrère, D.; Lasseur, C.; Lastovicka, T.; Laub, M.; Liko, D.; Lippmann, C.; Lindner, R.; Losasso, M.; Maier, A.; Mair, K.; Maley, P.; Mato Vila, P.; Moine, G.; Morant, J.; Moritz, M.; Moscicki, J.; Muecke, M.; Mueller, H.; Nakada, T.; Neufeld, N.; Ocariz, J.; Padilla Aranda, C.; Parzefall, U.; Patel, M.; Pepe-Altarelli, M.; Piedigrossi, D.; Pivk, M.; Pokorski, W.; Ponce, S.; Ranjard, F.; Riegler, W.; Renaud, J.; Roiser, S.; Rossi, A.; Roy, L.; Ruf, T.; Ruffinoni, D.; Saladino, S.; Sambade Varela, A.; Santinelli, R.; Schmelling, S.; Schmidt, B.; Schneider, T.; Schöning, A.; Schopper, A.; Seguinot, J.; Snoeys, W.; Smith, A.; Smith, A. C.; Somogyi, P.; Stoica, R.; Tejessy, W.; Teubert, F.; Thomas, E.; Toledo Alarcon, J.; Ullaland, O.; Valassi, A.; Vannerem, P.; Veness, R.; Wicht, P.; Wiedner, D.; Witzeling, W.; Wright, A.; Wyllie, K.; Ypsilantis, T.

    2008-08-01

    The LHCb experiment is dedicated to precision measurements of CP violation and rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN (Geneva). The initial configuration and expected performance of the detector and associated systems, as established by test beam measurements and simulation studies, is described.

  2. Ground Vibration Measurements at LHC Point 4

    SciTech Connect

    Bertsche, Kirk; Gaddi, Andrea; /CERN

    2012-09-17

    Ground vibration was measured at Large Hadron Collider (LHC) Point 4 during the winter shutdown in February 2012. This report contains the results, including power and coherence spectra. We plan to collect and analyze vibration data from representative collider halls to inform specifications for future linear colliders, such as ILC and CLIC. We are especially interested in vibration correlations between final focus lens locations.

  3. RENORM predictions of diffraction at LHC confirmed

    SciTech Connect

    Goulianos, Konstantin

    2015-04-10

    The RENORM model predictions of diffractive, total, and total-inelastic cross sections at the LHC are confirmed by recent measurements. The predictions of several other available models are discussed, highlighting their differences from RENORM, mainly arising from the way rapidity gap formation, low- and high-mass diffraction, unitarization, and hadronization are implemented.

  4. Soft QCD and Diffractive Physics at Lhc

    NASA Astrophysics Data System (ADS)

    Scapparone, Eugenio

    2012-12-01

    After a short introduction on the importance of the soft and of the diffractive studies in the understanding of minimum bias events, the main results obtained at LHC are discussed. This overview includes identified particle and inclusive measurements, minimum bias and underlying events, all of them shedding light on the soft process production mechanisms. The results of the inelastic cross-section measurements obtained by the LHC experiments and their compatibility are discussed together with the models used to extrapolate the data at low diffractive masses. A review of the most recent diffraction results is presented, showing the different approaches used by the LHC experiments, relying on different experimental techniques. The combination of the results obtained by ALICE, ATLAS, CMS, LHCb and TOTEM provides a wide sample of informations, covering an unprecedented pseudorapidity range. A detailed comparison between the obtained results is shown, followed by a critical discussion on the still existing discrepancies between the experimental data and the Monte Carlo used at LHC to simulate soft and diffractive physics.

  5. Dijet production at the LHC through unparticles

    SciTech Connect

    Agarwal, Neelima; Kumar, M. C.; Mathews, Prakash

    2009-08-01

    We report the phenomenological impact of unparticles in the production of dijet at the LHC. We compute the scalar, spin-1 and spin-2 unparticle contributions to the dijet cross sections and present our results in different kinematical distributions. We find that the scalar unparticle contribution is dominant over that of the spin-1 and spin-2 unparticles for the same coupling values.

  6. Phenomenology of flavon fields at the LHC

    SciTech Connect

    Tsumura, Koji; Velasco-Sevilla, Liliana

    2010-02-01

    We study low energy constraints from flavor violating processes, production, and decay at the LHC of a scalar field {phi} (flavon) associated to the breaking of a nonsupersymmetric Abelian family symmetry at the TeV scale. This symmetry is constrained to reproduce fermion masses and mixing, up to O(1) coefficients. The nonsupersymmetric gauged U(1) models considered are severely restricted by cancellation of anomalies and LEP bounds on contact interactions; consequently its phenomenology is out of the LHC reach. We therefore introduce an effective U(1) which is not gauged and is broken explicitly by a CP-odd term at the TeV scale. This helps us to explore flavor violating processes, production, and decay at the LHC for these kind of light scalars. In this context we first study the constraints on the flavon mass and its vacuum expectation value from low energy flavor changing processes such as {mu}{yields}e{gamma}. We find that a flavon of about m{sub {phi}}< or approx. 150 GeV could be experimentally allowed. These kinds of flavons could be significantly generated at the LHC via the gluon fusion mechanism and the single top production channel gu{yields}t{phi}. The produced flavons can have characteristic decay modes such as tc for m{sub {phi}}> or approx. m{sub t}, and {tau}{mu} for m{sub {phi}}< or approx. m{sub t}, which could be effectively useful to detect flavons.

  7. LOCAL DECOUPLING IN THE LHC INTERACTION REGIONS

    SciTech Connect

    PILAT,F.

    1999-09-07

    Local decoupling is a technique to correct coupling locally and operationally, that is, without a priori knowledge of the underlying skew quadrupole errors. The method is explained and applied to the correction of coupling in the interaction regions of the LHC at collision.

  8. Continuing u.s. participation in the lhc accelerator program

    SciTech Connect

    Syphers, M.J.; /Fermilab

    2005-12-01

    The U.S. LHC Accelerator Research Program (LARP) was established to enable U.S. accelerator specialists to take on active and important roles in the LHC accelerator project during its commissioning and early operations, and to be a major collaborator in future LHC performance upgrades. It is hoped that this follow-on effort to the U.S. contributions to the LHC accelerator project will improve the capabilities of the U.S. accelerator community in accelerator science and technology in order to more effectively use, develop, and preserve unique U.S. resources and capabilities during the LHC era.

  9. Every Day Is National Lab Day

    ERIC Educational Resources Information Center

    Bull, Glen

    2010-01-01

    President Barack Obama recently issued a call for increased hands-on learning in U.S. schools in an address at the National Academy of Sciences. Obama concluded that the future of the United States depends on one's ability to encourage young people to "create, and build, and invent." In this article, the author discusses National Lab Day (NLD)…

  10. POTENTIAL FOR HIGGS PHYSICS AT THE LHC AND SUPER-LHC.

    SciTech Connect

    CRANMER, K.S.

    2005-12-12

    The expected sensitivity of the LHC experiments to the discovery of the Higgs boson and the measurement of its properties is presented in the context of both the standard model and the its minimal supersymmetric extension. Prospects for a luminosity-upgraded ''Super-LHC'' are also presented. If it exists, the LHC should discover standard model Higgs boson, measure its mass accurately, and make various measurements of its couplings, spin and CP properties. In the context of the CP-conserving MSSM, the LHC should be able to discover one or more Higgs bosons over the entire m{sub A}-tan {beta} plane, with two or more observable in many cases. The large number of channels available insure a robust discovery and offer many opportunities for additional measurements. Observation of H {yields} {mu}{mu}, measurement of the tri-linear Higgs self-coupling, and various search channels are statistics-limited, and only possible with a luminosity upgrade. A luminosity upgrade would substantially improve some of the coupling measurements and generally extend the sensitivity in the MSSM Higgs plane. Efforts are ongoing to understand the upgrade of the LHC to the Super-LHC.

  11. Riley-Day syndrome

    MedlinePlus

    Riley-Day syndrome is an inherited disorder that affects nerves throughout the body. ... Riley-Day syndrome is passed down through families (inherited). A person must inherit a copy of the defective gene ...

  12. Riley-Day syndrome

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/001387.htm Riley-Day syndrome To use the sharing features on this page, please enable JavaScript. Riley-Day syndrome is an inherited disorder that affects nerves ...

  13. 2016 SPD: Day 2

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    advances in simulating sunspot formation. He and his collaborators have used high-performance computing to build a model that successfully reproduces many of the key properties of sunspots that are observed.In particular, these simulations track the motions of the magnetic field starting within the interior of the Sun (8000 km below the surface!). The magnetic field is generated and intensified by convection deep within the solar interior. Bundles of magnetic field then rise through the convection zone, eventually breaking through the solar surface and giving rise to sunspots.This process of tracking the flow as it travels from the convective layer all the way through the solar surface has resulted in what may be some of the highest fidelity simulations of sunspots thus far. The structures produced in these simulations compares very favorably with actual observations of sunspots including the asymmetry seen in most sunspots.Counting Spots on the SunContinuing the discussion of sunspots, Leif Svalgaard (Stanford University) next took us on a historical journey from the 1600s through the present. For the last 400 years starting with Galileo people have kept records of the number of sunspots visible on the Suns disk.One of Galileos drawings of his sunspot observations from 1612. [The Galileo Project]This turns out to be a very useful practice! Total solar irradiance, a measure used as input into climate models, is reconstructed from sunspot numbers. Therefore, the historical record of sunspots over the last 400 years impacts our estimates of the long-term trends in solar activity.Based on raw sunspot counts, studies have argued that solar activity has been steadily increasing over time. But could this be a misinterpretation resulting from the fact that our technology and therefore our ability to detect sunspots has improved over time? Svalgaard believes so.By studying and reconstructing 18th century telescopes, he demonstrates that modern-day sunspot counts are able to detect

  14. Growing degree day calculator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Degree-day benchmarks indicate discrete biological events in the development of insect pests. For the Sparganothis fruitworm, we have isolated all key development events and linked them to degree-day accumulations. These degree-day accumulations can greatly improve treatment timings for cranberry IP...

  15. Every Day Is Mathematical

    ERIC Educational Resources Information Center

    Barger, Rita H.; Jarrah, Adeeb M.

    2012-01-01

    March 14 is special because it is Pi Day. Mathematics is celebrated on that day because the date, 3-14, replicates the first three digits of pi. Pi-related songs, websites, trivia facts, and more are at the fingertips of interested teachers and students. Less celebrated, but still fairly well known, is National Metric Day, which falls on October…

  16. ASSEMBLY AND TEST OF A 120 MM BORE 15 T NB3SN QUADRUPOLE FOR THE LHC UPGRADE

    SciTech Connect

    Felice, H.; Caspi, S.; Cheng, D.; Dietderich, D.; Ferracin, P.; Hafalia, R.; Joseph, J.; Lizarazo, J.; Sabbi, G. L.; Wang, X.; Anerella, M.; Ghosh, A. K.; Schmalzle, J.; Wanderer, P.; Ambrosio, G.; Bossert, R.; Zlobin, A. V.

    2010-05-23

    In support of the Large Hadron Collider (LHC) luminosity upgrade, the US LHC Accelerator Research Program (LARP) has been developing a 1-meter long, 120 mm bore Nb{sub 3}Sn IR quadrupole magnet (HQ). With a design short sample gradient of 219 T/m at 1.9 K and a peak field approaching 15 T, one of the main challenges of this magnet is to provide appropriate mechanical support to the coils. Compared to the previous LARP Technology Quadrupole and Long Quadrupole magnets, the purpose of HQ is also to demonstrate accelerator quality features such as alignment and cooling. So far, 8 HQ coils have been fabricated and 4 of them have been assembled and tested in HQ01a. This paper presents the mechanical assembly and test results of HQ01a.

  17. LER-LHC injector workshop summary and super-ferric fast cycling injector in the SPS tunnel

    SciTech Connect

    Ambrosio, Giorgio; Hays, Steven; Huang, Yuenian; Johnstone, John; Kashikhin, Vadim; MacLachlan, James; Mokhov, Nikolai; Piekarz, Henryk; Sen, Tanaji; Shiltsev, Vladimir; de Rijk, Gijsbert; /CERN

    2007-03-01

    A Workshop on Low Energy Ring (LER) in the LHC tunnel as main injector was convened at CERN on October 11-12, 2006. We present the outline of the LER based on the presentations, and respond to the raised questions and discussions including the post-workshop studies. We also outline the possibility of using the LER accelerator technologies for the fast cycling injector accelerator in the SPS tunnel (SF-SPS). A primary goal for the LER (Low Energy Ring) injector accelerator is to inject 1.5 TeV proton beams into the LHC, instead of the current injection scheme with 0.45 TeV beams from the SPS. At this new energy, the field harmonics [1] of the LHC magnets are sufficiently satisfactory to prevent the luminosity losses expected to appear when applying the transfer of the 0.45 TeV SPS beams. In addition, a feasibility study of batch slip stacking in the LER has been undertaken with a goal of increasing in this way the LHC luminosity by up to a factor of 4. A combined luminosity increase may, therefore, be in the range of an order of magnitude. In the long term, the LER injector accelerator would greatly facilitate the implementation of a machine, which doubles the LHC energy (DLHC).

  18. Photon reflectivity distributions from the LHC beam screen and their implications on the arc beam vacuum system

    NASA Astrophysics Data System (ADS)

    Mahne, N.; Baglin, V.; Collins, I. R.; Giglia, A.; Pasquali, L.; Pedio, M.; Nannarone, S.; Cimino, R.

    2004-07-01

    In particle accelerators with intense positively charged bunched beams, an electron cloud may induce beam instabilities and the related beam induced electron multipacting (BIEM) can result in an undesired pressure rise. In a cryogenic machine such as the large hadron collider (LHC), the BIEM will introduce additional heat load. When present, synchrotron radiation (SR) may generate a significant number of photoelectrons, that may play a role in determining the onset and the detailed properties of the electron cloud related instability. Since electrons are constrained to move along field lines, those created on the accelerator equator in a strong vertical (dipole) field cannot participate in the e-cloud build-up. Therefore, for the LHC there has been a continuous effort to find solutions to absorb the photons on the equator. The solution adopted for the LHC dipole beam screens is a saw-tooth structure on the illuminated equator. SR from a bending magnet beamline at ELETTRA, Italy (BEAR) has been used to measure the reflectivities (forward, back-scattered and diffuse), for a flat and a saw-tooth structured Cu co-laminated surface using both white light SR, similar to the one emitted by LHC, and monochromatic light. Our data show that the saw-tooth structure does reduce the total reflectivity and modifies the photon energy distribution of the reflected photons. The implications of these results on the LHC arc vacuum system are discussed.

  19. The LHC's Next Big Mystery

    NASA Astrophysics Data System (ADS)

    Lincoln, Don

    2015-03-01

    When the sun rose over America on July 4, 2012, the world of science had radically changed. The Higgs boson had been discovered. Mind you, the press releases were more cautious than that, with "a new particle consistent with being the Higgs boson" being the carefully constructed phrase of the day. But, make no mistake, champagne corks were popped and backs were slapped. The data had spoken and a party was in order. Even if the observation turned out to be something other than the Higgs boson, the first big discovery from data taken at the Large Hadron Collider had been made.

  20. AAS 227: Day 2

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Editors Note:This week were at the 227th AAS Meeting in Kissimmee, FL. Along with several fellow authors from astrobites.com, I will bewritingupdates on selectedevents at themeeting and posting at the end of each day. Follow along here or atastrobites.com, or catch ourlive-tweeted updates from the@astrobites Twitter account. The usual posting schedule for AAS Nova will resumenext week.Welcome to Day 2 of the winter American Astronomical Society (AAS) meeting in Kissimmee! Several of us are attending the conference this year, and we will report highlights from each day here on astrobites. If youd like to see more timely updates during the day, we encourage you to follow @astrobites on twitter or search the #aas227 hashtag.Plenary Session: Black Hole Physics with the Event Horizon Telescope (by Susanna Kohler)If anyone needed motivation to wake up early this morning, they got it in the form of Feryal Ozel (University of Arizona) enthralling us all with exciting pictures, videos, and words about black holes and the Event Horizon Telescope. Ozel spoke to a packed room (at 8:30am!) about where the project currently stands, and where its heading in the future.The EHT has pretty much the coolest goal ever: actually image the event horizons of black holes in our universe. The problem is that the largest black hole we can look at (Sgr A*, in the center of our galaxy) has an event horizon size of 50 as. For this kind of resolution roughly equivalent to trying to image a DVD on the Moon! wed need an Earth-sized telescope. EHT has solved this problem by linking telescopes around the world, creating one giant, mm-wavelength effective telescope with a baseline the size of Earth.Besides producing awesome images, the EHT will be able to test properties of black-hole spacetime, the no-hair theorem, and general relativity (GR) in new regimes.Ozel walked us through some of the theory prep work we need to do now in order to get the most science out of the EHT, including devising new

  1. Specifications and Performances of Series Superfluid Helium Safety Relief Valves for the LHC

    NASA Astrophysics Data System (ADS)

    Perin, A.; Fontanive, V.

    2006-04-01

    Protecting the LHC magnets requires safety relief valves operating with 1.9 K pressurized superfluid helium at their inlet. Following the evaluation of prototype valves, a specification for the production of the 360 safety relief valves needed for the LHC was issued. The production of the safety valves was then awarded to an industrial contractor. The performances of pre-series valves were assessed for a variety of aspects including thermal performance, leak tightness in superfluid helium, dynamic behavior and resistance to intensive mechanical cycling. After the initial validation phase the series production was completed within the technical requirements of the specification. This paper describes the characteristics of the safety relief valves and the specifications for their industrial production. The performances of the pre-series valves are presented and an overview of the series production phase is given.

  2. Contextualized Magnetism in Secondary School: Learning from the LHC (CERN)

    ERIC Educational Resources Information Center

    Cid, Ramon

    2005-01-01

    Physics teachers in secondary schools usually mention the world's largest particle physics laboratory--CERN (European Organization for Nuclear Research)--only because of the enormous size of the accelerators and detectors used there, the number of scientists involved in their activities and also the necessary international scientific…

  3. 2016 SPD: Day 2

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    advances in simulating sunspot formation. He and his collaborators have used high-performance computing to build a model that successfully reproduces many of the key properties of sunspots that are observed.In particular, these simulations track the motions of the magnetic field starting within the interior of the Sun (8000 km below the surface!). The magnetic field is generated and intensified by convection deep within the solar interior. Bundles of magnetic field then rise through the convection zone, eventually breaking through the solar surface and giving rise to sunspots.This process of tracking the flow as it travels from the convective layer all the way through the solar surface has resulted in what may be some of the highest fidelity simulations of sunspots thus far. The structures produced in these simulations compares very favorably with actual observations of sunspots including the asymmetry seen in most sunspots.Counting Spots on the SunContinuing the discussion of sunspots, Leif Svalgaard (Stanford University) next took us on a historical journey from the 1600s through the present. For the last 400 years starting with Galileo people have kept records of the number of sunspots visible on the Suns disk.One of Galileos drawings of his sunspot observations from 1612. [The Galileo Project]This turns out to be a very useful practice! Total solar irradiance, a measure used as input into climate models, is reconstructed from sunspot numbers. Therefore, the historical record of sunspots over the last 400 years impacts our estimates of the long-term trends in solar activity.Based on raw sunspot counts, studies have argued that solar activity has been steadily increasing over time. But could this be a misinterpretation resulting from the fact that our technology and therefore our ability to detect sunspots has improved over time? Svalgaard believes so.By studying and reconstructing 18th century telescopes, he demonstrates that modern-day sunspot counts are able to detect

  4. Novel Geometries for the LHC Crab Cavity

    SciTech Connect

    B. Hall,G. Burt,C. Lingwood,Robert Rimmer,Haipeng Wang; Hall, B.; Burt, G.; Lingwood, C.; Rimmer, Robert; Wang, Haipeng

    2010-05-01

    The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.

  5. Smashing Protons: First Physics at the LHC

    SciTech Connect

    Miller, David

    2010-11-30

    The Large Hadron Collider, at CERN in Geneva, Switzerland, is the largest scientific instrument ever built. For nearly a year now, we have been smashing protons into each other with unprecedented energy, allowing us to peer into nature's most intimate depths. The world's largest and most complex cameras take snapshots of these collisions millions of times per second. These pictures reveal the smallest components of the universe - the quarks and gluons - and, someday, we hope, the elusive Higgs boson. Why do we need to build such an enormous machine in order to study particles more than a million times smaller than a speck of dust? This lecture will explain how the LHC and its detectors work, what the pictures from the LHC are telling us now, and how we will use this technology to explore the deepest secrets of the universe.

  6. Vector dark matter at the LHC

    NASA Astrophysics Data System (ADS)

    Kumar, Jason; Marfatia, Danny; Yaylali, David

    2015-11-01

    We consider monojet searches at the Large Hadron Collider (LHC) for spin-1 dark matter that interacts with quarks through a contact operator. If the dark matter particles are produced with longitudinal polarizations, then the production matrix element is enhanced by factors of the energy. We show that this particularly effective search strategy can test models for which the energy suppression scale of the operator is as large as 105 TeV . As such, these searches can probe a large class of models for which the contact-operator approximation is valid. We find that for contact operators that permit velocity-independent dark matter-nucleon scattering, LHC monojet searches for spin-1 dark matter are competitive with or far surpass direct-detection searches depending on whether the scattering is spin independent or spin dependent, respectively.

  7. Resonant mono Higgs at the LHC

    NASA Astrophysics Data System (ADS)

    Basso, Lorenzo

    2016-04-01

    In recent years, the production of a SM particle with large missing transverse momentum, dubbed mono-X searches, have gained increasing attention. After the discovery of the Higgs boson in 2012, the run-II of the LHC will now scrutinise its properties, looking for BSM physics. In particular, one could search for mono-Higgs signals, that are typically studied in models addressing dark matter. However, this signal can appear also in models addressing the neutrino masses, if additional heavier neutrinos with masses at the electroweak scale are present. The latter will couple to the SM neutrinos and the Higgs boson, yielding a type of mono-Higgs signal not considered for dark matter: the resonant production of a Higgs boson and missing energy. In this paper, we address the LHC exclusion power of the latter with dedicated detector simulations, and reinterpret it in a benchmark scenario for neutrino mass generation.

  8. Scalar explanation of diphoton excess at LHC

    NASA Astrophysics Data System (ADS)

    Han, Huayong; Wang, Shaoming; Zheng, Sibo

    2016-06-01

    Inspired by the diphoton signal excess observed in the latest data of 13 TeV LHC, we consider either a 750 GeV real scalar or pseudo-scalar responsible for this anomaly. We propose a concrete vector-like quark model, in which the vector-like fermion pairs directly couple to this scalar via Yukawa interaction. For this setting the scalar is mainly produced via gluon fusion, then decays at the one-loop level to SM diboson channels gg , γγ , ZZ , WW. We show that for the vector-like fermion pairs with exotic electric charges, such model can account for the diphoton excess and is consistent with the data of 8 TeV LHC simultaneously in the context of perturbative analysis.

  9. Jet energy calibration at the LHC

    SciTech Connect

    Schwartzman, Ariel

    2015-11-10

    In this study, jets are one of the most prominent physics signatures of high energy proton–proton (p–p) collisions at the Large Hadron Collider (LHC). They are key physics objects for precision measurements and searches for new phenomena. This review provides an overview of the reconstruction and calibration of jets at the LHC during its first Run. ATLAS and CMS developed different approaches for the reconstruction of jets, but use similar methods for the energy calibration. ATLAS reconstructs jets utilizing input signals from their calorimeters and use charged particle tracks to refine their energy measurement and suppress the effects of multiple p–p interactions (pileup). CMS, instead, combines calorimeter and tracking information to build jets from particle flow objects. Jets are calibrated using Monte Carlo (MC) simulations and a residual in situ calibration derived from collision data is applied to correct for the differences in jet response between data and Monte Carlo.

  10. Cornering diphoton resonance models at the LHC

    NASA Astrophysics Data System (ADS)

    Backović, Mihailo; Kulkarni, Suchita; Mariotti, Alberto; Sessolo, Enrico Maria; Spannowsky, Michael

    2016-08-01

    We explore the ability of the high luminosity LHC to test models which can explain the 750 GeV diphoton excess. We focus on a wide class of models where a 750 GeV singlet scalar couples to Standard Model gauge bosons and quarks, as well as dark matter. Including both gluon and photon fusion production mechanisms, we show that LHC searches in channels correlated with the diphoton signal will be able to probe wide classes of diphoton models with L ˜ 3000 fb-1 of data. Furthermore, models in which the scalar is a portal to the dark sector can be cornered with as little as L ˜ 30 fb-1.

  11. Jet energy calibration at the LHC

    DOE PAGESBeta

    Schwartzman, Ariel

    2015-11-10

    In this study, jets are one of the most prominent physics signatures of high energy proton–proton (p–p) collisions at the Large Hadron Collider (LHC). They are key physics objects for precision measurements and searches for new phenomena. This review provides an overview of the reconstruction and calibration of jets at the LHC during its first Run. ATLAS and CMS developed different approaches for the reconstruction of jets, but use similar methods for the energy calibration. ATLAS reconstructs jets utilizing input signals from their calorimeters and use charged particle tracks to refine their energy measurement and suppress the effects of multiplemore » p–p interactions (pileup). CMS, instead, combines calorimeter and tracking information to build jets from particle flow objects. Jets are calibrated using Monte Carlo (MC) simulations and a residual in situ calibration derived from collision data is applied to correct for the differences in jet response between data and Monte Carlo.« less

  12. LHC prospects for minimal decaying dark matter

    SciTech Connect

    Arcadi, Giorgio; Covi, Laura; Dradi, Federico E-mail: laura.covi@theorie.physik.uni-goettingen.de

    2014-10-01

    We study the possible signals at LHC of the minimal models of decaying dark matter. Those models are characterized by the fact that DM interacts with SM particles through renormalizable coupling with an additional heavier charged state. Such interaction allows to produce a substantial abundance of DM in the early Universe via the decay of the charged heavy state, either in- or out-of-equilibrium. Moreover additional couplings of the charged particle open up decay channels for the DM, which can nevertheless be sufficiently long-lived to be a good DM candidate and within reach of future Indirect Detection observations. We compare the cosmologically favored parameter regions to the LHC discovery reach and discuss the possibility of simultaneous detection of DM decay in Indirect Detection.

  13. Soft interaction model and the LHC data

    NASA Astrophysics Data System (ADS)

    Gotsman, E.; Levin, E.; Maor, U.

    2012-05-01

    Most models for soft interactions which were proposed prior to the measurements at the LHC, are only marginally compatible with LHC data, the Gotsma-Levin-Maor model has the same deficiency. In this paper we investigate possible causes of the problem, by considering separate fits to the high energy (W>500GeV), and low energy (W<500GeV) data. Our new results are moderately higher than our previous predictions. Our results for total and elastic cross sections are systematically lower that the recent Totem and Alice published values, while our results for the inelastic and forward slope agree with the data. If with additional experimental data, the errors are reduced, while the central cross section values remain unchanged, we will need to reconsider the physics on which our model is built.

  14. Novel Geometries for the LHC Crab Cavity

    SciTech Connect

    B. Hall, G. Burt, C. Lingwood, R. Rimmer, H. Wang

    2010-05-23

    The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.

  15. LHC benchmarks from flavored gauge mediation

    NASA Astrophysics Data System (ADS)

    Ierushalmi, N.; Iwamoto, S.; Lee, G.; Nepomnyashy, V.; Shadmi, Y.

    2016-07-01

    We present benchmark points for LHC searches from flavored gauge mediation models, in which messenger-matter couplings give flavor-dependent squark masses. Our examples include spectra in which a single squark — stop, scharm, or sup — is much lighter than all other colored superpartners, motivating improved quark flavor tagging at the LHC. Many examples feature flavor mixing; in particular, large stop-scharm mixing is possible. The correct Higgs mass is obtained in some examples by virtue of the large stop A-term. We also revisit the general flavor and CP structure of the models. Even though the A-terms can be substantial, their contributions to EDM's are very suppressed, because of the particular dependence of the A-terms on the messenger coupling. This holds regardless of the messenger-coupling texture. More generally, the special structure of the soft terms often leads to stronger suppression of flavor- and CP-violating processes, compared to naive estimates.

  16. Design Study of the High Luminosity LHC Recombination Dipole (D2)

    SciTech Connect

    Sabbi, GianLuca; Wang, Xiaorong

    2014-05-26

    The interaction region design of the high-luminosity LHC requires replacing the recombination dipole magnets (D2) with new ones. The preliminary specifications include an aperture of 105 mm, with 186 mm separation between the twin-aperture axes, and an operating field in the range of 3.5 to 4.5 T. The main design challenge is to decouple the magnetic field in the two apertures and ensure good field quality. The approach adopted for the present D2 magnets, using the iron yoke as a shield between the two apertures, leads to large saturation effects. In this study, we propose an alternative approach where the iron yoke is designed primarily for low saturation, and the resulting large but current-independent cross-talk between the apertures is corrected with an asymmetric arrangement of the conductor blocks. A preliminary solution based on the LHC dipole cable is presented, and the expected harmonics for geometric, saturation and persistent current effects are provided. Finally, the feasibility of an operating field at the high end of the range considered is discussed, to minimize the D2 magnet length and facilitate the space allocation for other components.

  17. Gap between jets at the LHC

    NASA Astrophysics Data System (ADS)

    Royon, Christophe

    2013-04-01

    We describe a NLL BFKL calculation implemented in the HERWIG MC of the gap between jets cross section, that represent a test of BFKL dynamics. We compare the predictions with recent measurements at the Tevatron and present predictions for the LHC. We also discuss the interesting process of looking for gap between jets in diffractive events when protons are detected in the ATLAS Forward Physics (AFP) detectors.

  18. Bottom production asymmetries at the LHC

    SciTech Connect

    Norrbin, E.; Vogt, R.

    1999-01-01

    We present results on bottom hadron production asymmetries at the LHC within both the Lund string fragmentation model and the intrinsic bottom model. The main aspects of the models are summarized and specific predictions for pp collisions at 14 TeV are given. Asymmetries are found to be very small at central rapidities increasing to a few percent at forward rapidities. At very large rapidities intrinsic production could dominate but this region is probably out of reach of any experiment.

  19. Color Sextet Scalars in Early LHC Experiments

    SciTech Connect

    Berger, Edmond L.; Cao Qinghong; Chen, Chuan-Ren; Shaughnessy, Gabe; Zhang Hao

    2010-10-29

    We explore the potential for discovery of an exotic color sextet scalar in same-sign top quark pair production in early running at the LHC. We present the first phenomenological analysis at colliders of color sextet scalars with full top quark spin correlations included. We demonstrate that one can measure the scalar mass, the top quark polarization, and confirm the scalar resonance with 1 fb{sup -1} of integrated luminosity. The top quark polarization can distinguish gauge triplet and singlet scalars.

  20. Electron lenses for particle collimation in LHC

    SciTech Connect

    Shiltsev, v.; /Fermilab

    2007-12-01

    Electron Lenses built and installed in Tevatron have proven themselves as safe and very reliable instruments which can be effectively used in hadron collider operation for a number of applications, including compensation of beam-beam effects [1], DC beam removal from abort gaps [2], as a diagnostic tool. In this presentation we - following original proposal [3] - consider in more detail a possibility of using electron lenses with hollow electron beam for ion and proton collimation in LHC.

  1. Calculation of water activation for the LHC

    NASA Astrophysics Data System (ADS)

    Vollaire, Joachim; Brugger, Markus; Forkel-Wirth, Doris; Roesler, Stefan; Vojtyla, Pavol

    2006-06-01

    The management of activated water in the Large Hadron Collider (LHC) at CERN is a key concern for radiation protection. For this reason, the induced radioactivity of the different water circuits is calculated using the Monte-Carlo (MC) code FLUKA. The results lead to the definition of procedures to be taken into account during the repair and maintenance of the machine, as well as to measures being necessary for a release of water into the environment. In order to assess the validity of the applied methods, a benchmark experiment was carried out at the CERN-EU High Energy Reference Field (CERF) facility, where a hadron beam (120 GeV) is impinging on a copper target. Four samples of water, as used at the LHC, and different in their chemical compositions, were irradiated near the copper target. In addition to the tritium activity measured with a liquid scintillation counter, the samples were also analyzed using gamma spectroscopy in order to determine the activity of the gamma emitting isotopes such as Be7 and Na24. While for the latter an excellent agreement between simulation and measurement was found, for the calculation of tritium a correction factor is derived to be applied for future LHC calculations in which the activity is calculated by direct scoring of produced nuclei. A simplified geometry representing the LHC Arc sections is then used to evaluate the different calculation methods with FLUKA. By comparing these methods and by taking into account the benchmark results, a strategy for the environmental calculations can be defined.

  2. Status of the TOTEM experiment at LHC

    NASA Astrophysics Data System (ADS)

    Baechler, J.; Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Berardi, V.; Berretti, M.; Bossini, E.; Bozzo, M.; Brogi, P.; Brücken, E.; Buzzo, A.; Cafagna, F.; Calicchio, M.; Catanesi, M. G.; Covault, C.; Csörgő, T.; Deile, M.; Eggert, K.; Eremin, V.; Ferretti, R.; Ferro, F.; Fiergolski, A.; Garcia, F.; Giani, S.; Greco, V.; Grzanka, L.; Heino, J.; Hilden, T.; Intonti, M. R.; Kašpar, J.; Kopal, J.; Kundrát, V.; Kurvinen, K.; Lami, S.; Latino, G.; Lauhakangas, R.; Leszko, T.; Lippmaa, E.; Lokajíček, M.; Lo Vetere, M.; Lucas Rodríguez, F.; Macrí, M.; Magaletti, L.; Mercadante, A.; Minafra, N.; Minutoli, S.; Nemes, F.; Niewiadomski, H.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Österberg, K.; Palazzi, P.; Procházka, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Saarikko, H.; Sanguinetti, G.; Santroni, A.; Scribano, A.; Snoeys, W.; Sziklai, J.; Taylor, C.; Turini, N.; Vacek, V.; Vítek, M.; Welti, J.; Whitmore, J.

    2013-08-01

    The TOTEM experiment is dedicated to the measurement of the total proton-proton cross-section with the luminosity-independent method and the study of elastic and diffractive scattering processes. Two tracking telescopes, T1 and T2, integrated in the CMS detector, cover the pseudo-rapidity region between 3.1 and 6.5 on both sides of the interaction point IP5. The Roman Pot (RP) stations are located at distances of ±147 m and ±220 m with respect to the interaction point to measure the very forward scattered protons at very small angles. During the LHC technical stop in winter 2010/2011, the TOTEM experiment was completed with the installation of the T1 telescope and the RP stations at ±147 m. In 2011, the LHC machine provided special optics with the large ß*=90 m, allowing TOTEM to measure the elastic scattering differential cross-section, down to the four-momentum transfer squared |t|=2×10-2 GeV2. Using the optical theorem and extrapolation of the differential cross-section to t=0 (optical point), the total p-p cross-section at the LHC energy of √{ s} = 7 TeV could be computed for the first time. Furthermore we measured with standard LHC beam optics and the energy of √{ s} = 7 TeV the forward charged particle pseudorapidity density dn/dη in the range of 5.3<|η|<6.4. The status of the experiment, the performance of the detectors with emphasis on the RPs are described and the first physics results are presented.

  3. Dark Matter Jets at the LHC

    SciTech Connect

    Bai, Yang; Rajaraman, Arvind; /UC, Irvine

    2012-03-28

    We argue that dark matter particles which have strong interactions with the Standard Model particles are not excluded by current astrophysical constraints. These dark matter particles have unique signatures at colliders; instead of missing energy, the dark matter particles produce jets. We propose a new search strategy for such strongly interacting particles by looking for a signal of two trackless jets. We show that suitable cuts can plausibly allow us to find these signals at the LHC even in early data.

  4. Popular Chat Day Q & A

    MedlinePlus

    ... Day / Popular Chat Day Q & A Popular Chat Day Q & A Print Read students’ most popular questions ... Cool Order Free Materials National Drugs & Alcohol Chat Day Chat Day Participant FAQs Popular Chat Day Q & ...

  5. Description of Day-to-Day Variability in IRI

    NASA Astrophysics Data System (ADS)

    Bilitza, Dieter; Liu, Boding; Rodriguez, Joseph E.

    2013-04-01

    The International Reference Ionosphere (IRI) describes the monthly average behavior of Earth's ionosphere based on most of the accessible and reliable ground and space observations of ionospheric parameters. IRI is doing an excellent job in accurately representing these average conditions as countless comparisons with additional data have shown and as acknowledged by the fact that international organizations (COSPAR, URSI, ISO, ECSS) have accepted IRI as their ionosphere standard. However, with our ever-increasing dependence on space technology it has become important to go beyond the monthly averages and to provide a description of the day-to-day variability of the ionosphere. We will review past and ongoing efforts to provide IRI users with a quantitative description of ionospheric variability depending on altitude, time of day, time of year, latitude and solar and magnetic activity. We will present new results from an analysis of ISIS and Alouette topside sounder data. The IRI team is also pursuing the development of an IRI Real-Time (IRI-RT) that uses assimilative algorithms or updating procedures to combine IRI with real-time data for a more accurate picture of current ionospheric conditions. We will review the status of these activities and report on latest results.

  6. My Lucky Day

    ERIC Educational Resources Information Center

    Olvey, Maura

    2010-01-01

    Teaching based on problem solving brings challenges for the teacher, primarily that of finding problems with multiple access points that accommodate all students. This article narrates the author's lucky day as she discovers the Four fours problem which impacted her passion for teaching math. The day she presented the Four fours problem to her…

  7. The Presidents' Day Game

    ERIC Educational Resources Information Center

    Maxwell, D. Jackson

    2008-01-01

    The history behind the holiday commonly called "Presidents' Day" is a bit confusing. It started as a federal holiday called Washington's Birthday. It was a day set aside to honor George Washington for his accomplishments as a founding father of the country. Later, many northern states began to recognize Abraham Lincoln's Birthday as well for his…

  8. Day of the Dead

    ERIC Educational Resources Information Center

    Dann, Tammy; Murphy, Amy

    2012-01-01

    Foreign Language in Elementary School (FLES) teachers in the West Des Moines schools incorporate the Day of the Dead into the fourth grade curriculum each year. The teachers discuss the Day of the Dead celebration at the Art Center, and many ask for volunteers from fourth grade to participate in the event. Student presentations include a wide…

  9. Family Science Day

    ERIC Educational Resources Information Center

    McCubbins, Sara; Thomas, Bethany; Vetere, Michael

    2014-01-01

    This article describes a family-friendly science day event that encourages scientific discovery through hands-on activities, while also providing an opportunity to learn about scientific careers from actual research scientists and science educators, thereby raising awareness of the importance of STEM in our society. The one-day event bought…

  10. School Building Day, 2001.

    ERIC Educational Resources Information Center

    Council of Educational Facility Planners, International, Scottsdale, AZ.

    This document presents information and development materials about "School Building Day" (an event spotlighting the school facility and developing support and pride in the community's schools) to help local school districts conduct their own "School Building Day" to be held on April 20th of 2001. Included are lists of suggested activities and…

  11. Science Challenge Day

    ERIC Educational Resources Information Center

    Siegel, Deborah

    2013-01-01

    Science fairs can be good motivators, but as extracurricular activities, they leave some students behind. However, by staging a Science Challenge Day at school, educators can involve all students in doing everything from choosing activities to judging projects. This article presents a model for running a successful Science Challenge Day. The…

  12. Rainy Day Activities.

    ERIC Educational Resources Information Center

    Texas Child Care, 1997

    1997-01-01

    Experienced caregivers plan ahead for rainy days. This article describes specific rainy day activities for young children, such as books and crafts to learn about rain (rain in a jar, making a rainbow), simple cooking activities (taffy pull, cinnamon candy tea), and games (mummy wrap, hunt the thimble, rain lotto). (EV)

  13. RED-LETTER DAYS

    EPA Science Inventory

    The word "red-letter" is an adjective meaning "of special significance." It's origin is from the practice of marking Christian holy days in red letters on calendars. The "red-letter days" to which I refer occurred while I was a graduate student of ...

  14. The day-to-day variability in ionospheric electric fields and currents

    NASA Technical Reports Server (NTRS)

    Kirchhoff, V. W. J. H.; Carpenter, L. A.

    1976-01-01

    The daily variations in ionospheric drift velocities are examined from incoherent scatter measurements at Millstone Hill. The data with summed Kp greater than 24 behave differently from those with low magnetic activity and basically follow the convection pattern but have large day-to-day variations. The influence of the magnetic conjugate point is discussed, and solar cycle variations are examined in conjunction with geomagnetic variations. Ionospheric currents calculated by using a semidiurnal neutral wind model are in good agreement with ground-based magnetograms for low magnetic activity, but the E region neutral wind model appears to be applicable only to this case.

  15. Sbottoms of natural NMSSM at the LHC

    NASA Astrophysics Data System (ADS)

    Beuria, Jyotiranjan; Chatterjee, Arindam; Datta, AseshKrishna

    2016-08-01

    Search for the bottom squarks (sbottoms) at the Large Hadron Collider (LHC) has recently assumed a heightened focus in the hunt for Supersymmetry (SUSY). The popular framework of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) could conceive a naturally light sbottom which can easily be consistent with available constraints from the experiments at the LHC. Phenomenology of such sbottoms could in principle be as striking as that for a light top squark (stop) thanks to a rather nontrivial neutralino sector (with appreciable mixing among the neutral higgsinos and the singlino) that the scenario gives rise to. Nonetheless, finding such sbottoms would require a moderately large volume of data (˜300 fb-1) at the 13 TeV run of the LHC. A multi-channel analysis establishing a generic depletion of events in the usual 2 b- jets + [InlineMediaObject not available: see fulltext.] T final state while registering, in conjunction, characteristically significant rates in various multi-lepton final states accompanied by b- jets might point not only to the presence of light sbottom(s) but could also shed crucial light on their compositions and the (singlino) nature of the lightest SUSY particle (LSP).

  16. Processing LHC data in the UK

    PubMed Central

    Colling, D.; Britton, D.; Gordon, J.; Lloyd, S.; Doyle, A.; Gronbech, P.; Coles, J.; Sansum, A.; Patrick, G.; Jones, R.; Middleton, R.; Kelsey, D.; Cass, A.; Geddes, N.; Clark, P.; Barnby, L.

    2013-01-01

    The Large Hadron Collider (LHC) is one of the greatest scientific endeavours to date. The construction of the collider itself and the experiments that collect data from it represent a huge investment, both financially and in terms of human effort, in our hope to understand the way the Universe works at a deeper level. Yet the volumes of data produced are so large that they cannot be analysed at any single computing centre. Instead, the experiments have all adopted distributed computing models based on the LHC Computing Grid. Without the correct functioning of this grid infrastructure the experiments would not be able to understand the data that they have collected. Within the UK, the Grid infrastructure needed by the experiments is provided by the GridPP project. We report on the operations, performance and contributions made to the experiments by the GridPP project during the years of 2010 and 2011—the first two significant years of the running of the LHC. PMID:23230163

  17. Development of MQXF: The Nb3Sn low-β quadrupole for the HiLumi LHC

    DOE PAGESBeta

    Ferracin, P.; G. Ambrosio; Anerella, M.; Ballarino, A.; Bajas, H.; Bajko, M.; Bordini, B.; Bossert, R.; Cheng, D. W.; Dietderich, D. R.; et al

    2015-12-18

    The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating atmore » magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Europeen pour la Recherche Nucleaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. Lastly, this paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.« less

  18. Experiment Dashboard for Monitoring of the LHC Distributed Computing Systems

    NASA Astrophysics Data System (ADS)

    Andreeva, J.; Devesas Campos, M.; Tarragon Cros, J.; Gaidioz, B.; Karavakis, E.; Kokoszkiewicz, L.; Lanciotti, E.; Maier, G.; Ollivier, W.; Nowotka, M.; Rocha, R.; Sadykov, T.; Saiz, P.; Sargsyan, L.; Sidorova, I.; Tuckett, D.

    2011-12-01

    LHC experiments are currently taking collisions data. A distributed computing model chosen by the four main LHC experiments allows physicists to benefit from resources spread all over the world. The distributed model and the scale of LHC computing activities increase the level of complexity of middleware, and also the chances of possible failures or inefficiencies in involved components. In order to ensure the required performance and functionality of the LHC computing system, monitoring the status of the distributed sites and services as well as monitoring LHC computing activities are among the key factors. Over the last years, the Experiment Dashboard team has been working on a number of applications that facilitate the monitoring of different activities: including following up jobs, transfers, and also site and service availabilities. This presentation describes Experiment Dashboard applications used by the LHC experiments and experience gained during the first months of data taking.

  19. Volunteer Clouds and Citizen Cyberscience for LHC Physics

    NASA Astrophysics Data System (ADS)

    Aguado Sanchez, Carlos; Blomer, Jakob; Buncic, Predrag; Chen, Gang; Ellis, John; Garcia Quintas, David; Harutyunyan, Artem; Grey, Francois; Lombrana Gonzalez, Daniel; Marquina, Miguel; Mato, Pere; Rantala, Jarno; Schulz, Holger; Segal, Ben; Sharma, Archana; Skands, Peter; Weir, David; Wu, Jie; Wu, Wenjing; Yadav, Rohit

    2011-12-01

    Computing for the LHC, and for HEP more generally, is traditionally viewed as requiring specialized infrastructure and software environments, and therefore not compatible with the recent trend in "volunteer computing", where volunteers supply free processing time on ordinary PCs and laptops via standard Internet connections. In this paper, we demonstrate that with the use of virtual machine technology, at least some standard LHC computing tasks can be tackled with volunteer computing resources. Specifically, by presenting volunteer computing resources to HEP scientists as a "volunteer cloud", essentially identical to a Grid or dedicated cluster from a job submission perspective, LHC simulations can be processed effectively. This article outlines both the technical steps required for such a solution and the implications for LHC computing as well as for LHC public outreach and for participation by scientists from developing regions in LHC research.

  20. Support Structure Design of the $\\hbox{Nb}_{3}\\hbox{Sn}$ Quadrupole for the High Luminosity LHC

    SciTech Connect

    Juchno, M.; Ambrosio, G.; Anerella, M.; Cheng, D.; Felice, H.; Ferracin, P.; Perez, J. C.; Prin, H.; Schmalzle, J.

    2014-10-31

    New low-β quadrupole magnets are being developed within the scope of the High Luminosity LHC (HL-LHC) project in collaboration with the US LARP program. The aim of the HLLHC project is to study and implement machine upgrades necessary for increasing the luminosity of the LHC. The new quadrupoles, which are based on the Nb₃Sn superconducting technology, will be installed in the LHC Interaction Regions and will have to generate a gradient of 140 T/m in a coil aperture of 150 mm. In this paper, we describe the design of the short model magnet support structure and discuss results of the detailed 3D numerical analysis performed in preparation for the first short model test.

  1. Status of LHC crab activity simulations and beam studies

    SciTech Connect

    Calaga,R.; Assman, R.; Barranco, J.; Barranco, J.; Calaga, R.; Caspers, F.; Ciapala, E.; De-Maria, R.; Koutchouk, J. P.; Linnecar, T.; Metral, E.; Morita, A.; Solyak, N.; Sun, Y.; Tomas, R.; Tuckmantel, J.; Weiler, T.; Zimmermann, F.

    2009-05-04

    The LHC crab cavity program is advancing rapidly towards a first prototype which is anticipated to be tested during the early stages of the LHC phase I upgrade and commissioning. The general project status and some aspects related to crab optics, collimation, aperture constraints, impedances, noise effects. beam transparency and machine protection critical for a safe and robust operation of LHC beams with crab cavities are addressed here.

  2. Superconducting Magnet Technology for the Upgrade

    SciTech Connect

    Todesco, E.; Ambrosio, G.; Ferracin, P.; Rifflet, J. M.; Sabbi, G. L.; Segreti, M.; Nakamoto, T.; van Weelderen, R.; Xu, Q.

    2015-10-01

    In this section we present the magnet technology for the High Luminosity LHC. After a short review of the project targets and constraints, we discuss the main guidelines used to determine the technology, the field/gradients, the operational margins, and the choice of the current density for each type of magnet. Then we discuss the peculiar aspects of each class of magnet, with special emphasis on the triplet.

  3. Pregnancy - identifying fertile days

    MedlinePlus

    ... between days 7 and 20 of a woman's menstrual cycle. In order to become pregnant, having sex every ... hours of ovulation. If you have an irregular menstrual cycle, an ovulation predictor kit can help you know ...

  4. Career Day 2012

    NASA Video Gallery

    More than 200 high school juniors and seniors with interests in science, technology, engineering and math met one-on-one with professionals at NASA's Langley Research Center during Career Day 2012,...

  5. Stennis Day Camper

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Sara Beth Casey, 5, proudly displays her artwork, 'Planets.' Sara Beth created the art as a student of Stennis Day Camp, a free camp for Stennis Space Center employees' children whose schools have not resumed since Hurricane Katrina hit the region on Aug. 29. The camp has registered nearly 200 children and averages 100 children each day. The camp will continue until all schools are back in session.

  6. Mathematical formulation to predict the harmonics of the superconducting Large Hadron Collider magnets

    NASA Astrophysics Data System (ADS)

    Sammut, Nicholas; Bottura, Luca; Micallef, Joseph

    2006-01-01

    CERN is currently assembling the LHC (Large Hadron Collider) that will accelerate and bring in collision 7 TeV protons for high energy physics. Such a superconducting magnet-based accelerator can be controlled only when the field errors of production and installation of all magnetic elements are known to the required accuracy. The ideal way to compensate the field errors obviously is to have direct diagnostics on the beam. For the LHC, however, a system solely based on beam feedback may be too demanding. The present baseline for the LHC control system hence requires an accurate forecast of the magnetic field and the multipole field errors to reduce the burden on the beam-based feedback. The field model is the core of this magnetic prediction system, that we call the field description for the LHC (FIDEL). The model will provide the forecast of the magnetic field at a given time, magnet operating current, magnet ramp rate, magnet temperature, and magnet powering history. The model is based on the identification and physical decomposition of the effects that contribute to the total field in the magnet aperture of the LHC dipoles. Each effect is quantified using data obtained from series measurements, and modeled theoretically or empirically depending on the complexity of the physical phenomena involved. This paper presents the developments of the new finely tuned magnetic field model and, using the data accumulated through series tests to date, evaluates its accuracy and predictive capabilities over a sector of the machine.

  7. Current Lead Design for the Accelerator Project for Upgrade of LHC

    SciTech Connect

    Brandt, Jeffrey S.; Cheban, Sergey; Feher, Sandor; Kaducak, Marc; Nobrega, Fred; Peterson, Tom

    2010-01-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. In collaboration with Brookhaven National Laboratory, Fermilab is developing sub-systems for an upgrade of the LHC final focus magnet systems. A concept of main and auxiliary helium flow was developed that allows the superconductor to remain cold while the lead body warms up to prevent upper section frosting. The auxiliary flow will subsequently cool the thermal shields of the feed box and the transmission line cryostats. A thermal analysis of the current lead central heat exchange section was performed using analytic and FEA techniques. A method of remote soldering was developed that allows the current leads to be field replaceable. The remote solder joint was designed to be made without flux or additional solder, and able to be remade up to ten full cycles. A method of upper section attachment was developed that allows high pressure sealing of the helium volume. Test fixtures for both remote soldering and upper section attachment for the 13 kA lead were produced. The cooling concept, thermal analyses, and test results from both remote soldering and upper section attachment fixtures are presented.

  8. Quench propagation and heating in the superconducting 600 A auxiliary busbars of the LHC

    NASA Astrophysics Data System (ADS)

    Herzog, R.; Calvi, M.; Sonnemann, F.

    2002-05-01

    In the Large Hadron Collider (LHC) at CERN 22 km of flexible superconducting cable, the auxiliary busbar cable, will conduct currents of up to 600 A to a large number of corrector magnets distributed throughout the accelerator. A prototype cable with 42 active conductors underwent several experiments to measure the hot spot temperature and the quench propagation velocity as a function of the current. The former was evaluated for various energy extraction scenarios as they are foreseen for the LHC corrector circuits. The experimental results and the heat flow simulations show that the quench behavior in this busbar prototype is strongly influenced by the heat flow through the insulation material (polyimide) into the helium bath, leading to stable configurations above the critical temperature Tc for currents between 250 A and 500 A. Special attention was paid to the study of discontinuities in the wires, like feed-throughs, where the wire is not immersed in liquid helium, and joints, where the wire cross-section is increased. The experiments and simulations led to a thorough understanding of the quench process in the wires of the prototype cable, which resulted in guidelines for the design, the use and the installation of the cable in the LHC.

  9. Probing top-Z dipole moments at the LHC and ILC

    DOE PAGESBeta

    Röntsch, Raoul; Schulze, Markus

    2015-08-11

    We investigate the weak electric and magnetic dipole moments of top quark-Z boson interactions at the Large Hadron Collider (LHC) and the International Linear Collider (ILC). Their vanishingly small magnitude in the Standard Model makes these couplings ideal for probing New Physics interactions and for exploring the role of top quarks in electroweak symmetry breaking. In our analysis, we consider the production of two top quarks in association with a Z boson at the LHC, and top quark pairs mediated by neutral gauge bosons at the ILC. These processes yield direct sensitivity to top quark-Z boson interactions and complement indirectmore » constraints from electroweak precision data. Our computation is accurate to next-to-leading order in QCD, we include the full decay chain of top quarks and the Z boson, and account for theoretical uncertainties in our constraints. Furthermore, we find that LHC experiments will soon be able to probe weak dipole moments for the first time.« less

  10. On the day-to-day variation of the equatorial electrojet during quiet periods

    NASA Astrophysics Data System (ADS)

    Yamazaki, Y.; Richmond, A. D.; Maute, A.; Liu, H.-L.; Pedatella, N.; Sassi, F.

    2014-08-01

    It has been known for a long time that the equatorial electrojet varies from day to day even when solar and geomagnetic activities are very low. The quiet time day-to-day variation is considered to be due to irregular variability of the neutral wind, but little is known about how variable winds drive the electrojet variability. We employ a numerical model introduced by Liu et al. (2013), which takes into account weather changes in the lower atmosphere and thus can reproduce ionospheric variability due to forcing from below. The simulation is run for May and June 2009. Constant solar and magnetospheric energy inputs are used so that day-to-day changes will arise only from lower atmospheric forcing. The simulated electrojet current shows day-to-day variability of ±25%, which produces day-to-day variations in ground level geomagnetic perturbations near the magnetic equator. The current system associated with the day-to-day variation of the equatorial electrojet is traced based on a covariance analysis. The current pattern reveals return flow at both sides of the electrojet, in agreement with those inferred from ground-based magnetometer data in previous studies. The day-to-day variation in the electrojet current is compared with those in the neutral wind at various altitudes, latitudes, and longitudes. It is found that the electrojet variability is dominated by the zonal wind at 100-120 km altitudes near the magnetic equator. These results suggest that the response of the zonal polarization electric field to variable zonal winds is the main source of the day-to-day variation of the equatorial electrojet during quiet periods.

  11. AAS 227: Day 2

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Editors Note:This week were at the 227th AAS Meeting in Kissimmee, FL. Along with several fellow authors from astrobites.com, I will bewritingupdates on selectedevents at themeeting and posting at the end of each day. Follow along here or atastrobites.com, or catch ourlive-tweeted updates from the@astrobites Twitter account. The usual posting schedule for AAS Nova will resumenext week.Welcome to Day 2 of the winter American Astronomical Society (AAS) meeting in Kissimmee! Several of us are attending the conference this year, and we will report highlights from each day here on astrobites. If youd like to see more timely updates during the day, we encourage you to follow @astrobites on twitter or search the #aas227 hashtag.Plenary Session: Black Hole Physics with the Event Horizon Telescope (by Susanna Kohler)If anyone needed motivation to wake up early this morning, they got it in the form of Feryal Ozel (University of Arizona) enthralling us all with exciting pictures, videos, and words about black holes and the Event Horizon Telescope. Ozel spoke to a packed room (at 8:30am!) about where the project currently stands, and where its heading in the future.The EHT has pretty much the coolest goal ever: actually image the event horizons of black holes in our universe. The problem is that the largest black hole we can look at (Sgr A*, in the center of our galaxy) has an event horizon size of 50 as. For this kind of resolution roughly equivalent to trying to image a DVD on the Moon! wed need an Earth-sized telescope. EHT has solved this problem by linking telescopes around the world, creating one giant, mm-wavelength effective telescope with a baseline the size of Earth.Besides producing awesome images, the EHT will be able to test properties of black-hole spacetime, the no-hair theorem, and general relativity (GR) in new regimes.Ozel walked us through some of the theory prep work we need to do now in order to get the most science out of the EHT, including devising new

  12. Thunder day increase

    NASA Astrophysics Data System (ADS)

    Hilberg, Steven D.

    1984-04-01

    A report issued by the Illinois State Water Survey concludes that annual values of thunder days for North America exhibited a general increase of about 15% from 1901 to 1945, followed by a general decrease of 10% from 1945 to 1980. A study of the variability of thunder days across North America showed a general decrease with time, particularly after 1940. A major finding of this study is that frequencies of thunderstorms over areas as large as the North American continent show major long-term trends.The report, “Temporal Distribution of Global Thunder Days,” summarizes the results of a 1-year study by Stanley A. Changnon, Jr., and Chin-Fei Hsu of the temporal variations of thunder-day records during 1901-1980 using quality weather records from weather stations scattered around the globe. A thunder day is recorded when one or more peals of thunder are heard anytime during the 24-hour period from midnight to midnight, which is consistent with the definition of a thunderstorm used at first-order weather stations since 1897. They found most stations in the northern hemisphere north of 45° latitude exhibited a general increase in thunder activity from 1901 to 1980. The project was funded by the National Science Foundation.

  13. Supersymmetric dark matter after LHC run 1

    NASA Astrophysics Data System (ADS)

    Bagnaschi, E. A.; Buchmueller, O.; Cavanaugh, R.; Citron, M.; De Roeck, A.; Dolan, M. J.; Ellis, J. R.; Flächer, H.; Heinemeyer, S.; Isidori, G.; Malik, S.; Martínez Santos, D.; Olive, K. A.; Sakurai, K.; de Vries, K. J.; Weiglein, G.

    2015-10-01

    Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, tilde{χ }^01, assumed here to be the lightest SUSY particle (LSP) and thus the dark matter (DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly degenerate next-to-lightest supersymmetric particle such as the lighter stau tilde{τ }1, stop tilde{t}1 or chargino tilde{χ }^± 1, resonant annihilation via direct-channel heavy Higgs bosons H / A, the light Higgs boson h or the Z boson, and enhanced annihilation via a larger Higgsino component of the LSP in the focus-point region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2, and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the {tilde{τ }_1} coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be explored at the LHC via searches for / E_T events and long-lived charged particles, whereas their H / A funnel, focus-point and tilde{χ }^± 1 coannihilation regions can largely be explored by the LZ and Darwin DM direct detection experiments. We find that the dominant DM mechanism in our pMSSM10 analysis is tilde{χ }^± 1 coannihilation: parts of its parameter space can be explored by the LHC, and a larger portion by future direct DM searches.

  14. Supersymmetric Dark Matter after LHC Run 1

    SciTech Connect

    Bagnaschi, E. A.; Buchmueller, O.; Cavanaugh, R.; Citron, M.; De Roeck, A.; Dolan, M. J.; Ellis, J. R.; Flacher, H.; Heinemeyer, S.; Isidori, G.; Malik, S.; Santos, D. Martinez; Olive, K. A.; Sakurai, K.; de Vries, K. J.; Weiglein, G.

    2015-10-23

    Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, χ~01, assumed here to be the lightest SUSY particle (LSP) and thus the dark matter (DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly degenerate next-to-lightest supersymmetric particle such as the lighter stau τ~1, stop t~1 or chargino χ1, resonant annihilation via direct-channel heavy Higgs bosons H / A, the light Higgs boson h or the Z boson, and enhanced annihilation via a larger Higgsino component of the LSP in the focus-point region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2, and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the τ~1 coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be explored at the LHC via searches for /ET events and long-lived charged particles, whereas theirH / A funnel, focus-point and χ1 coannihilation regions can largely be explored by the LZ and Darwin DM direct detection experiments. Furthermore, we find that the dominant DM mechanism in our pMSSM10 analysis is χ~±1 coannihilation: parts of its parameter space can be explored by the LHC, and a larger portion by future direct DM searches.

  15. Supersymmetric Dark Matter after LHC Run 1

    DOE PAGESBeta

    Bagnaschi, E. A.; Buchmueller, O.; Cavanaugh, R.; Citron, M.; De Roeck, A.; Dolan, M. J.; Ellis, J. R.; Flacher, H.; Heinemeyer, S.; Isidori, G.; et al

    2015-10-23

    Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, χ~01, assumed here to be the lightest SUSY particle (LSP) and thus the dark matter (DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly degenerate next-to-lightest supersymmetric particle such as the lighter stau τ~1, stop t~1 or chargino χ~±1, resonant annihilation via direct-channel heavy Higgs bosons H / A, the light Higgs boson h or the Z boson, and enhanced annihilation via a larger Higgsino component of the LSP in the focus-pointmore » region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2, and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the τ~1 coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be explored at the LHC via searches for /ET events and long-lived charged particles, whereas theirH / A funnel, focus-point and χ~±1 coannihilation regions can largely be explored by the LZ and Darwin DM direct detection experiments. Furthermore, we find that the dominant DM mechanism in our pMSSM10 analysis is χ~±1 coannihilation: parts of its parameter space can be explored by the LHC, and a larger portion by future direct DM searches.« less

  16. Black Holes versus Supersymmetry at the LHC

    NASA Astrophysics Data System (ADS)

    Roy, Arunava; Cavaglia, Marco

    2007-11-01

    Supersymmetry and extra dimensions are the two most promising candidates for new physics at the TeV scale. Supersymmetric particles or extra-dimensional effects could soon be observed at the Large Hadron Collider. In this paper we assess the distinguishability of supersymmetry and black hole events at the LHC. Black hole events are simulated with the CATFISH black hole generator. Supersymmetry simulations use a combination of PYTHIA and ISAJET, the latter providing the mass spectrum. Our analysis shows that supersymmetry and black hole events at the Large Hadron Collider can be easily discriminated.

  17. MCFM for the Tevatron and the LHC

    SciTech Connect

    Campbell, John M.; Ellis, R.K.; /Fermilab

    2010-07-01

    A summary is given of the current status of the next-to-leading order (NLO) parton-level integrator MCFM. Some details are given about the Higgs + 2-jet process and the production and decay of t{bar t}, both of which have recently been added to the code. Using MCFM, comparisons between the Tevatron running at {radical}s = 2 TeV and the LHC running at {radical}s = 7 TeV are made for standard model process including the production of Higgs bosons. The case for running the Tevatron until 16fb{sup -1} are accumulated by both detectors is sketched.

  18. Top quark physics at the LHC

    NASA Astrophysics Data System (ADS)

    Kim, Tae Jeong

    2014-04-01

    In 2011, an integrated luminosity of more than 5 fb-1 at 7 TeV has been delivered by the LHC. The measurement of the cross section in top quark pair production and in single top quark production, top quark mass, top quark properties and new physics searches in top quark decays have been performed at the CMS experiment with various integrated luminosities. An overview of the latest results of these measurements and searches by the time of ICFP 2012 conference will be presented.

  19. Early black hole signals at the LHC

    SciTech Connect

    Koch, Ben; Bleicher, Marcus; Stoecker, Horst

    2007-10-26

    The production of mini black holes due to large extra dimensions is a speculative but possible scenario. We survey estimates for di-jet suppression, and multi-mono-jet emission due to black hole production. We further look for a possible sub-scenario which is the formation of a stable or meta-stable black hole remnant (BHR). We show that the beauty of such objects is, that they are relatively easy to observe, even in the early phase of LHC running.

  20. Precision Electroweak Physics at the LHC

    NASA Astrophysics Data System (ADS)

    Freitas, Ayres

    2015-04-01

    The current status of precision tests of the electroweak Standard Model is summarized, and a short review of the theory input from higher-order loop corrections is given. The most constraining quantities are the masses and couplings of the W and Z bosons, and it is shown how these put strong bounds on various examples of new physics. Furthermore, the impact of current and future LHC data on electroweak precision tests is described in some detail. It is also briefly discussed how measurements of anomalous gauge boson couplings provide complementary information about the electroweak theory.

  1. Higgs boson photoproduction at the LHC

    SciTech Connect

    Ducati, M. B. Gay; Silveira, G. G.

    2011-07-15

    We present the current development of the photoproduction approach for the Higgs boson with its application to pp and pA collisions at the LHC. We perform a different analysis for the Gap Survival Probability, where we consider a probability of 3% and also a more optimistic value of 10% based on the HERA data for dijet production. As a result, the cross section for the exclusive Higgs boson production is about 2 fb and 6 fb in pp collisions and 617 and 2056 fb for pPb collisions, considering the gap survival factor of 3% and 10%, respectively.

  2. Higgs boson at LHC: a diffractive opportunity

    SciTech Connect

    Ducati, M. B. Gay; Silveira, G. G.

    2009-03-23

    An alternative process is presented for diffractive Higgs boson production in peripheral pp collisions, where the particles interact through the Double Pomeron Exchange. The event rate is computed as a central-rapidity distribution for Tevatron and LHC energies leading to a result around 0.6 pb, higher than the predictions from previous approaches. Therefore, this result arises as an enhanced signal for the detection of the Higgs boson in hadron colliders. The predictions for the Higgs boson photoproduction are compared to the ones obtained from a similar approach proposed by the Durham group, enabling an analysis of the future developments of its application to pp and AA collisions.

  3. Particle physics with the LHC data

    SciTech Connect

    Hagiwara, Kaoru

    2012-07-27

    In this talk, I give reasons why we regard GUT as a part of the Standard Model of Elementary Particle Physics that explain all phenomena observed at high energy experiments and in the universe, with a few notable exceptions. It is based on my introduction-to-elementary-particle-physics lectures for the first year graduate students at Sokendai, Graduate University for Advanced Studies. No new observation is made, but I think that it is important for us to examine the LHC data from the GUT viewpoint together with our fresh students.

  4. Searching for Unexpected Physics at the LHC

    NASA Astrophysics Data System (ADS)

    Zurek, Kathryn M.

    2011-03-01

    These TASI lectures consider low mass hidden sectors from Hidden Valleys, Quirks and Unparticles. We show how each corresponds to a different limit of the same class of models: hidden sectors with non-abelian gauge groups with mass gaps well below a TeV that communicate to the Standard Model through weak scale suppressed higher dimension operators. We provide concrete examples of such models and discuss LHC signatures. Lastly we turn to discussing the application of Hidden Valleys to dark matter sectors.

  5. Tau Flavour Violation at the LHC

    SciTech Connect

    Carquin, E.

    2009-04-17

    We study the relevance of neutrino oscillation data for sparticle decays that violate the {tau} lepton number at the LHC, in the context of the Constrained Minimal Supersymmetric Extension of the Standard Model (CMSSM) and in SU(5) extensions of the theory. We study the conditions required for {chi}{sub 2}{yields}{chi}+{tau}{sup {+-}}{mu}{sup {+-}} decays to yield observable tau flavour violation, for cosmologically interesting values of the neutralino relic density. We present detailed studies of the relevant supersymmetric parameter space and pay particular emphasis to signals from tau hadronisation, that are analysed using PYTHIA event simulation.

  6. Jet quenching measurements with ATLAS at LHC

    SciTech Connect

    Brooks, W. K.

    2010-08-04

    A broad program of measurements is planned for heavy ion collisions in ATLAS. With up to a factor of 30 increase in collision energy compared to existing data, significant new insights are anticipated to be obtained with the first data measured. Global features of the LHC collisions will be accessible with the early data and will set the stage for the precision measurements to follow. ATLAS is particularly well suited for exploration of ''jet quenching,'' the extinction of energetic jets in the hot dense medium. Observations of heavy quark jet suppression will be possible with unprecedented energy reach and statistical precision, potentially yielding new insights into the basic mechanisms involved.

  7. Hadronization via coalescence at RHIC and LHC

    NASA Astrophysics Data System (ADS)

    Minissale, V.; Scardina, F.; Greco, V.

    2016-05-01

    An hadronization model that includes coalescence and fragmentation is used in this work to obtain predictions at both RHIC and LHC energy for light and strange hadrons transverse momentum spectra (π, p, k, Λ) and baryon to meson ratios (p/π, Λ/k) in a wide range of pT. This is accomplished without changing coalescence parameters. The ratios p/π and Λ/K shows the right behaviour except for some lack of baryon yield in a limited pT range around 6 GeV. This would indicate that the AKK fragmentation functions is too flat at pT < 8 GeV.

  8. Vertex finding with deformable templates at LHC

    NASA Astrophysics Data System (ADS)

    Stepanov, Nikita; Khanov, Alexandre

    1997-02-01

    We present a novel vertex finding technique. The task is formulated as a discrete-continuous optimisation problem in a way similar to the deformable templates approach for the track finding. Unlike the track finding problem, "elastic hedgehogs" rather than elastic arms are used as deformable templates. They are initialised by a set of procedures which provide zero level approximation for vertex positions and track parameters at the vertex point. The algorithm was evaluated using the simulated events for the LHC CMS detector and demonstrated good performance.

  9. Towards LHC physics with nonlocal Standard Model

    NASA Astrophysics Data System (ADS)

    Biswas, Tirthabir; Okada, Nobuchika

    2015-09-01

    We take a few steps towards constructing a string-inspired nonlocal extension of the Standard Model. We start by illustrating how quantum loop calculations can be performed in nonlocal scalar field theory. In particular, we show the potential to address the hierarchy problem in the nonlocal framework. Next, we construct a nonlocal abelian gauge model and derive modifications of the gauge interaction vertex and field propagators. We apply the modifications to a toy version of the nonlocal Standard Model and investigate collider phenomenology. We find the lower bound on the scale of nonlocality from the 8 TeV LHC data to be 2.5-3 TeV.

  10. Heavy Flavor Simplified Models at the LHC

    SciTech Connect

    Essig, Rouven; Izaguirre, Eder; Kaplan, Jared; Wacker, Jay G.; /SLAC

    2012-04-03

    We consider a comprehensive set of simplified models that contribute to final states with top and bottom quarks at the LHC. These simplified models are used to create minimal search strategies that ensure optimal coverage of new heavy flavor physics involving the pair production of color octets and triplets. We provide a set of benchmarks that are representative of model space, which can be used by experimentalists to perform their own optimization of search strategies. For data sets larger than 1 fb{sup -1}, same-sign dilepton and 3b search regions become very powerful. Expected sensitivities from existing and optimized searches are given.

  11. LHC searches for exotic new particles

    NASA Astrophysics Data System (ADS)

    Golling, Tobias

    2016-09-01

    A coherent description of the ATLAS and CMS program of searches for physics beyond the Standard Model of particle physics (except supersymmetry) is subject of this review. The theoretical motivation for new phenomena and the associated phenomenology are discussed. The search approach and philosophy by the experiments are presented in detail with illustrative examples both from Run-1 and early Run-2 of the LHC. The searches are largely driven by a diverse set of experimental signatures predicted by the various hypotheses of new physics.

  12. Material characterisation and preliminary mechanical design for the HL-LHC shielded beam screens operating at cryogenic temperatures.

    NASA Astrophysics Data System (ADS)

    Garion, C.; Dufay-Chanat, L.; Koettig, T.; Machiocha, W.; Morrone, M.

    2015-12-01

    The High Luminosity LHC project (HL-LHC) aims at increasing the luminosity (rate of collisions) in the Large Hadron Collider (LHC) experiments by a factor of 10 beyond the original design value (from 300 to 3000 fb-1). It relies on new superconducting magnets, installed close to the interaction points, equipped with new beam screen. This component has to ensure the vacuum performance together with shielding the cold mass from physics debris and screening the cold bore cryogenic system from beam induced heating. The beam screen operates in the range 40-60 K whereas the magnet cold bore temperature is 1.9 K. A tungsten-based material is used to absorb the energy of particles. In this paper, measurements of the mechanical and physical properties of such tungsten material are shown at room and cryogenic temperature. In addition, the design and the thermal mechanical behaviour of the beam screen assembly are presented also. They include the heat transfer from the tungsten absorbers to the cooling pipes and the supporting system that has to minimise the heat inleak into the cold mass. The behaviour during a magnet quench is also presented.

  13. The operation of the LHC accelerator complex (1/2)

    ScienceCinema

    None

    2011-10-06

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  14. The operation of the LHC accelerator complex (2/2)

    ScienceCinema

    None

    2011-10-06

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  15. Tevatron-for-LHC Report: Preparations for Discoveries

    SciTech Connect

    Buescher, V.; Carena, Marcela S.; Dobrescu, Bogdan A.; Mrenna, S.; Rainwater, D.; Schmitt, M.

    2006-08-01

    This is the ''TeV4LHC'' report of the ''Physics Landscapes'' Working Group, focused on facilitating the start-up of physics explorations at the LHC by using the experience gained at the Tevatron. We present experimental and theoretical results that can be employed to probe various scenarios for physics beyond the Standard Model.

  16. The operation of the LHC accelerator complex (1/2)

    SciTech Connect

    2010-04-07

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  17. The operation of the LHC accelerator complex (2/2)

    SciTech Connect

    2010-04-09

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  18. CMS tracker performance and readiness for LHC Run II

    NASA Astrophysics Data System (ADS)

    Viliani, L.

    2016-07-01

    The CMS tracker performance during LHC Run I is reviewed. The latest results of both pixel and strip detectors following the first LHC Long Shutdown (LS1) are then presented. Results from detector calibration and commissioning, together with a description of operations and repairs done during LS1, will be shown.

  19. Spin Measurement in Top Quark Events at the LHC

    SciTech Connect

    Linacre, Jacob

    2015-01-01

    Measurements of polarisation and spin correlations are presented in events with top quarks produced in pp collisions at the LHC. The data correspond to integrated luminosities of $5 fb^{-1}$ at $\\sqrt{s}$ = 7 TeV and 20 $fb^{-1}$ at $\\sqrt{s}$ = 8 TeV collected with the ATLAS and CMS detectors. The top quark polarization is measured in both single top quark production in the t-channel and $t\\bar{t}$ pair-production, from the angular distributions of charged leptons in the rest frame of their parent top quark. The spin correlations are measured in $t\\bar{t}$ events using various angular distributions of the decay products. The measurements are made using both template fitting methods and by unfolding the distributions to the parton-level, where differential measurements with respect to the invariant mass, rapidity, and transverse momentum of the $t\\bar{t}$ system are also made. The spin correlation measurements are used to search for new physics in the form of a light top squark or an anomalous top quark chromo-magnetic dipole moment. All measurements are found to be in agreement with predictions of the standard model.

  20. OPTIMIZATION OF OPEN MIDPLANE DIPOLE DESIGN FOR LHC IR UPGRADE.

    SciTech Connect

    GUPTA, R.; ANERELLA, M.; GHOSH, A.; HARRISON, M.; SCHMALZLE, J.; WANDERER, P.; MOKHOV, N.

    2005-05-16

    This paper presents the optimized designs of an ''open midplane dipole'' [1] for ''dipole first optics'' [2] for the proposed luminosity upgrade of the Large Hadron Collider (LHC). It was found [3] that in this design at luminosity of 10{sup 35} cm{sup -2} s{sup -1}, the peak power density in the coils can be up to two orders of magnitude higher than that at the present baseline luminosity (10{sup 34} cm{sup -2} s{sup -1}). This comes from a large quantity of spray particles from Interaction Point (IP) that is mostly concentrated at the midplane. The ''open midplane dipole'' design is the only design so far that has been found to provide reliable quench-stable operation with a lifetime of the critical components of at least ten years. In addition to a summary of magnetic, mechanical and energy deposition calculations for various iterations, the inherent benefits and challenges associated with the ''open midplane dipole'' design are also discussed. Results are presented for a recently proposed attractive option with the dipole splitted in two with a warm absorber placed between the two [4].

  1. Marketing Your Day Camp.

    ERIC Educational Resources Information Center

    Coleman, George

    1997-01-01

    Marketing strategies for day camps include encouraging camp staff to get involved in organizations involving children, families, and communities; holding camp fairs; offering the use of camp facilities to outside groups; hosting sport leagues and local youth outings; planning community fairs; and otherwise involving the camp in the community. (LP)

  2. First Day of School

    ERIC Educational Resources Information Center

    Bort, Nancy

    2004-01-01

    In this brief article, the author, a science teacher at F. C. Hammond Middle School in Alexandria, Virginia, describes how the setting up of a simple science experiment on the first day of school can get students excited about learning science. The experiment involves heating a small amount of water in a flask, then covering the opening of the…

  3. Make a Splash Day

    ERIC Educational Resources Information Center

    Coverdale, Greg; Rust, April; Jensen, Belinda

    2004-01-01

    At the annual, all-day events-sponsored by Project WET (Water Education for Teachers) and held in nearly every state across the country each September--students participate in interactive activities and exhibits to learn about water resources and explore how human behaviors, such as development and recreation, can affect the quality of the…

  4. Family Day Care Handbook.

    ERIC Educational Resources Information Center

    Community Coordinated Child Care (4-C) in Dane County, Inc., Madison, WI.

    This handbook provides both general and specific information on child development and child care to help adults who are providing child care in their homes. Information is presented in six sections which describe: (1) the family day care system, the occupation of caregiver, and the development of relationships; (2) development of a health program,…

  5. One Play a Day

    ERIC Educational Resources Information Center

    Blankenship, Mark

    2007-01-01

    Undergraduate theater students rarely get the chance to work on a major world premiere, but this year hundreds of them will. Currently, more than 70 colleges and universities are participating in "365 Days/365 Plays," an ambitious project from Pulitzer Prize-winning playwright Suzan-Lori Parks. Every week, as they mount their portion of this epic…

  6. Day Care: Nutrition.

    ERIC Educational Resources Information Center

    Foster, Florence P.; And Others

    This collection of 12 short, bilingual papers on nutrition and preschool children is part of a series of papers on various aspects of day care published by the Canadian Department of Health and Welfare. Each paper is presented in both English and French. Topics dealt with include an overview of children's nutritional needs; development of…

  7. An Earth Day Reader.

    ERIC Educational Resources Information Center

    Moser, Don, Ed.

    1990-01-01

    Presents what the author believes to be some of the most important environmental books published since Earth Day 1970. Discusses each selection and how it provides the historical background, basic information, and appreciation necessary to understand the character of our environmental dilemma and our need to address it. (MCO)

  8. Sun-Earth Day

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Michael Sandras, a member of the Pontchartrain Astronomical Society, explains his solar telescope to students of Second Street in Bay St. Louis, Hancock County and Nicholson elementary schools in StenniSphere's Millennium Hall on April 10. The students participated in several hands-on activities at Stennis Space Center's Sun-Earth Day celebration.

  9. Scheduling: Seven Period Day

    ERIC Educational Resources Information Center

    Williamson, Ronald

    2010-01-01

    Driven by stable or declining financial resources many school districts are considering the costs and benefits of a seven-period day. While there is limited evidence that any particular scheduling model has a greater impact on student learning than any other, it is clear that the school schedule is a tool that can significantly impact teacher…

  10. We Love Science Day.

    ERIC Educational Resources Information Center

    Kepler, Lynne

    1986-01-01

    Describes the goals and outcomes of the "We Love Science Day" programs that resulted from the inservice course, "Creative Integration of Science in Elementary Education" for Pennsylvania teachers. Provides samples of the hands-on activities that were offered to students, parents, and teachers. Includes a calendar of extracurricular science…

  11. Fabulous Weather Day

    ERIC Educational Resources Information Center

    Marshall, Candice; Mogil, H. Michael

    2007-01-01

    Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. Students learn how meteorologists collect data about the weather, how they study wind, temperature, precipitation, basic types/characteristics of clouds, and how they forecast. The project helps the students grow in…

  12. International School Library Day.

    ERIC Educational Resources Information Center

    Clyde, Laurel A.

    2001-01-01

    Describes the development of an International School Library Day and discusses activities in Australian school libraries. Highlights include the development of Web pages; sponsorship by national, state, or provincial associations; publicity materials; joint activities with other countries; student involvement; and activities with public libraries.…

  13. 90-Day Cycle Handbook

    ERIC Educational Resources Information Center

    Park, Sandra; Takahashi, Sola

    2013-01-01

    90-Day Cycles are a disciplined and structured form of inquiry designed to produce and test knowledge syntheses, prototyped processes, or products in support of improvement work. With any type of activity, organizations inevitably encounter roadblocks to improving performance and outcomes. These barriers might include intractable problems at…

  14. Seize the Day

    ERIC Educational Resources Information Center

    Berkey, Tim

    2008-01-01

    In order to improve what happens in classrooms, a considerable amount of work needs to take place between teachers and principals. This can only happen if campus leaders make dramatic shifts in how and where they spend their daily time. Principals can have a greater impact on teaching and learning by transforming their work one day at a time. The…

  15. Every Child, Every Day

    ERIC Educational Resources Information Center

    Allington, Richard L.; Gabriel, Rachael E.

    2012-01-01

    We know more now than we ever did before about how to make every child a successful reader, write Allington and Gabriel in this research review. Yet, few students regularly receive the best reading instruction we know how to give. The authors present research supporting their recommendation that every child, every day, should (1) read something he…

  16. Magnetic fields and scintillator performance

    SciTech Connect

    Green, D.; Ronzhin, A.; Hagopian, V.

    1995-06-01

    Experimental data have shown that the light output of a scintillator depends on the magnitude of the externally applied magnetic fields, and that this variation can affect the calorimeter calibration and possibly resolution. The goal of the measurements presented here is to study the light yield of scintillators in high magnetic fields in conditions that are similar to those anticipated for the LHC CMS detector. Two independent measurements were performed, the first at Fermilab and the second at the National High Magnetic Field Laboratory at Florida State University.

  17. PanDA: Exascale Federation of Resources for the ATLAS Experiment at the LHC

    NASA Astrophysics Data System (ADS)

    Barreiro Megino, Fernando; Caballero Bejar, Jose; De, Kaushik; Hover, John; Klimentov, Alexei; Maeno, Tadashi; Nilsson, Paul; Oleynik, Danila; Padolski, Siarhei; Panitkin, Sergey; Petrosyan, Artem; Wenaus, Torre

    2016-02-01

    After a scheduled maintenance and upgrade period, the world's largest and most powerful machine - the Large Hadron Collider(LHC) - is about to enter its second run at unprecedented energies. In order to exploit the scientific potential of the machine, the experiments at the LHC face computational challenges with enormous data volumes that need to be analysed by thousand of physics users and compared to simulated data. Given diverse funding constraints, the computational resources for the LHC have been deployed in a worldwide mesh of data centres, connected to each other through Grid technologies. The PanDA (Production and Distributed Analysis) system was developed in 2005 for the ATLAS experiment on top of this heterogeneous infrastructure to seamlessly integrate the computational resources and give the users the feeling of a unique system. Since its origins, PanDA has evolved together with upcoming computing paradigms in and outside HEP, such as changes in the networking model, Cloud Computing and HPC. It is currently running steadily up to 200 thousand simultaneous cores (limited by the available resources for ATLAS), up to two million aggregated jobs per day and processes over an exabyte of data per year. The success of PanDA in ATLAS is triggering the widespread adoption and testing by other experiments. In this contribution we will give an overview of the PanDA components and focus on the new features and upcoming challenges that are relevant to the next decade of distributed computing workload management using PanDA.

  18. Probing U(1) extensions of the MSSM at the LHC Run I and in dark matter searches

    NASA Astrophysics Data System (ADS)

    Bélanger, G.; Da Silva, J.; Laa, U.; Pukhov, A.

    2015-09-01

    The U(1) extended supersymmetric standard model (UMSSM) can accommodate a Higgs boson at 125 GeV without relying on large corrections from the top/stop sector. After imposing LHC results on the Higgs sector, on B-physics and on new particle searches as well as dark matter constraints, we show that this model offers two viable dark matter candidates, the right-handed (RH) sneutrino or the neutralino. Limits on super-symmetric partners from LHC simplified model searches are imposed using SM odelS and allow for light squarks and gluinos. Moreover the upper limit on the relic abundance often favours scenarios with long-lived particles. Searches for a Z ' at the LHC remain the most unambiguous probes of this model. Interestingly, the D-term contributions to the sfermion masses allow to explain the anomalous magnetic moment of the muon in specific corners of the parameter space with light smuons or left-handed (LH) sneutrinos. We finally emphasize the interplay between direct searches for dark matter and LHC simplified model searches.

  19. Simplified Models for LHC New Physics Searches

    SciTech Connect

    Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Chivukula, R.Sekhar; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig, Rouven,; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; /more authors..

    2012-06-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first {approx} 50-500 pb{sup -1} of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  20. Novel Geometries for the LHC Crab Cavity

    SciTech Connect

    Hall, B.; Burt, G.; Smith, J. D.A.; Rimmer, R.; Wang, H.; Delayen, J.; Calaga, R.

    2009-05-01

    In 2017 the LHC is envisioned to increase its luminosity via an upgrade. This upgrade is likely to require a large crossing angle hence a crab cavity is required to align the bunches prior to collision. There are two possible schemes for crab cavity implementation, global and local. In a global crab cavity the crab cavity is far from the IP and the bunch rotates back and forward as it traverses around the accelerator in a closed orbit. For this scheme a two-cell elliptical squashed cavity at 800 MHz is preferred. To avoid any potential beam instabilities all the parasitic modes of the cavities must be damped strongly, however crab cavities have lower order and same order modes in addition to the usual higher order modes and hence a novel damping scheme must be used to provide sufficient damping of these modes. In the local scheme two crab cavities are placed at each side of the IP two start and stop rotation of the bunches. This would require crab cavities much smaller transversely than in the global scheme but the frequency cannot be increased any higher due to the long bunch length of the LHC beam. This will require a novel compact crab cavity design. A superconducting version of a two rod coaxial deflecting cavity as a suitable design is proposed in this paper.

  1. MSSM Electroweak Baryogenesis and LHC Data

    SciTech Connect

    Carena, Marcela; Nardini, Germano; Quiros, Mariano; Wagner, Carlos E.M.

    2013-02-01

    Electroweak baryogenesis is an attractive scenario for the generation of the baryon asymmetry of the universe as its realization depends on the presence at the weak scale of new particles which may be searched for at high energy colliders. In the MSSM it may only be realized in the presence of light stops, and with moderate or small mixing between the left- and right-handed components. Consistency with the observed Higgs mass around 125 GeV demands the heavier stop mass to be much larger than the weak scale. Moreover the lighter stop leads to an increase of the gluon-gluon fusion Higgs production cross section which seems to be in contradiction with indications from current LHC data. We show that this tension may be considerably relaxed in the presence of a light neutralino with a mass lower than about 60 GeV, satisfying all present experimental constraints. In such a case the Higgs may have a significant invisible decay width and the stop decays through a three or four body decay channel, including a bottom quark and the lightest neutralino in the final state. All these properties make this scenario testable at a high luminosity LHC.

  2. Torsion phenomenology at the CERN LHC

    SciTech Connect

    Belyaev, A. S.; Shapiro, I. L.; Vale, M. A. B. do

    2007-02-01

    We explore the potential of the CERN Large Hadron Collider (LHC) to test the dynamical torsion parameters. The form of the torsion action can be established from the requirements of consistency of effective quantum field theory. The most phenomenologically relevant part of the torsion tensor is dual to a massive axial vector field. This axial vector has geometric nature, that means it does not belong to any representation of the gauge group of the SM extension or GUT theory. At the same time, torsion should interact with all fermions, that opens the way for the phenomenological applications. We demonstrate that LHC collider can establish unique constraints on the interactions between fermions and torsion field considerably exceeding present experimental lower bounds on the torsion couplings and its mass. It is also shown how possible nonuniversal nature of torsion couplings due to the renormalization group running between the Planck and TeV energy scales can be tested via the combined analysis of Drell-Yan and tt production processes.

  3. CERN LHC signals from warped extra dimensions

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh; Belyaev, Alexander; Krupovnickas, Tadas; Perez, Gilad; Virzi, Joseph

    2008-01-01

    We study production of Kaluza-Klein (KK) gluons at the Large Hadron Collider (LHC) in the framework of a warped extra dimension with the standard model fields propagating in the bulk. We show that the detection of the KK gluon is challenging since its production is suppressed by small couplings to the proton’s constituents. Moreover, the KK gluon decays mostly to top pairs due to an enhanced coupling and hence is broad. Nevertheless, we demonstrate that for MKKG≲4TeV, 100fb-1 of data at the LHC can provide discovery of the KK gluon. We utilize a sizable left-right polarization asymmetry from the KK gluon resonance to maximize the signal significance, and we explore the novel feature of extremely highly energetic “top-jets.” We briefly discuss how the detection of electroweak gauge KK states (Z/W) faces a similar challenge since their leptonic decays (golden modes) are suppressed. Our analysis suggests that other frameworks, for example, little Higgs, which rely on UV completion via strong dynamics might face similar challenges, namely, (1) suppressed production rates for the new particles (such as Z'), due to their “light-fermion-phobic” nature, and (2) difficulties in detection since the new particles are broad and decay predominantly to third generation quarks and longitudinal gauge bosons.

  4. Simplified models for LHC new physics searches

    NASA Astrophysics Data System (ADS)

    Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Sekhar Chivukula, R.; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig (Editor, Rouven; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; Freitas, Ayres; Gainer, James S.; Gershtein, Yuri; Gray, Richard; Gregoire, Thomas; Gripaios, Ben; Gunion, Jack; Han, Tao; Haas, Andy; Hansson, Per; Hewett, JoAnne; Hits, Dmitry; Hubisz, Jay; Izaguirre, Eder; Kaplan, Jared; Katz, Emanuel; Kilic, Can; Kim, Hyung-Do; Kitano, Ryuichiro; Koay, Sue Ann; Ko, Pyungwon; Krohn, David; Kuflik, Eric; Lewis, Ian; Lisanti (Editor, Mariangela; Liu, Tao; Liu, Zhen; Lu, Ran; Luty, Markus; Meade, Patrick; Morrissey, David; Mrenna, Stephen; Nojiri, Mihoko; Okui, Takemichi; Padhi, Sanjay; Papucci, Michele; Park, Michael; Park, Myeonghun; Perelstein, Maxim; Peskin, Michael; Phalen, Daniel; Rehermann, Keith; Rentala, Vikram; Roy, Tuhin; Ruderman, Joshua T.; Sanz, Veronica; Schmaltz, Martin; Schnetzer, Stephen; Schuster (Editor, Philip; Schwaller, Pedro; Schwartz, Matthew D.; Schwartzman, Ariel; Shao, Jing; Shelton, Jessie; Shih, David; Shu, Jing; Silverstein, Daniel; Simmons, Elizabeth; Somalwar, Sunil; Spannowsky, Michael; Spethmann, Christian; Strassler, Matthew; Su, Shufang; Tait (Editor, Tim; Thomas, Brooks; Thomas, Scott; Toro (Editor, Natalia; Volansky, Tomer; Wacker (Editor, Jay; Waltenberger, Wolfgang; Yavin, Itay; Yu, Felix; Zhao, Yue; Zurek, Kathryn; LHC New Physics Working Group

    2012-10-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the Large Hadron Collider (LHC) and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the ‘Topologies for Early LHC Searches’ workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first ˜50-500 pb-1 of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  5. ATLAS Distributed Computing in LHC Run2

    NASA Astrophysics Data System (ADS)

    Campana, Simone

    2015-12-01

    The ATLAS Distributed Computing infrastructure has evolved after the first period of LHC data taking in order to cope with the challenges of the upcoming LHC Run-2. An increase in both the data rate and the computing demands of the Monte-Carlo simulation, as well as new approaches to ATLAS analysis, dictated a more dynamic workload management system (Prodsys-2) and data management system (Rucio), overcoming the boundaries imposed by the design of the old computing model. In particular, the commissioning of new central computing system components was the core part of the migration toward a flexible computing model. A flexible computing utilization exploring the use of opportunistic resources such as HPC, cloud, and volunteer computing is embedded in the new computing model; the data access mechanisms have been enhanced with the remote access, and the network topology and performance is deeply integrated into the core of the system. Moreover, a new data management strategy, based on a defined lifetime for each dataset, has been defined to better manage the lifecycle of the data. In this note, an overview of an operational experience of the new system and its evolution is presented.

  6. LHC Signals from Warped Extra Dimensions

    SciTech Connect

    Agashe, K.; Belyaev, A.; Krupovnickas, T.; Perez, G.; Virzi, J.

    2006-12-06

    We study production of Kaluza-Klein gluons (KKG) at the Large Hadron Collider (LHC) in the framework of a warped extra dimension with the Standard Model (SM) fields propagating in the bulk. We show that the detection of KK gluon is challenging since its production is suppressed by small couplings to the proton's constituents. Moreover, the KK gluon decaysmostly to top pairs due to an enhanced coupling and hence is broad. Nevertheless, we demonstrate that for MKKG<~;; 4 TeV, 100 fb-1 of data at the LHC can provide discovery of the KK gluon. We utilize a sizeable left-right polarization asymmetry from the KK gluon resonance to maximize the signal significance, and we explore the novel feature of extremely highly energetic"top-jets." We briefly discuss how the detection of electroweak gauge KK states (Z/W) faces a similar challenge since their leptonic decays ("golden" modes) are suppressed. Our analysis suggests that other frameworks, for example little Higgs, which rely on UV completion via strong dynamics might face similar challenges, namely (1) Suppressed production rates for the new particles (such as Z'), due to their"lightfermion-phobic" nature, and (2) Difficulties in detection since the new particles are broad and decay predominantly to third generation quarks and longitudinal gauge bosons.

  7. Exclusive diffractive photon bremsstrahlung at the LHC

    NASA Astrophysics Data System (ADS)

    Lebiedowicz, Piotr; Szczurek, Antoni

    2013-06-01

    We calculate differential distributions for the pp→ppγ reaction at the LHC energy s=14TeV. We consider diffractive classical bremsstrahlung mechanisms including effects of the non-point-like nature of protons. In addition, we take into account (vector meson)-pomeron, photon-pion, and photon-pomeron exchange processes for the first time in the literature. Predictions for the total cross section and several observables related to these processes, e.g., differential distributions in pseudorapidities and transverse momenta of photons or protons are shown and discussed. The integrated diffractive bremsstrahlung cross section (Eγ>100GeV) is only of the order of μb. We try to identify regions of the phase space where one of the mechanisms dominates. The classical bremsstrahlung dominates at large forward/backward photon pseudorapidities, close to the pseudorapidities of scattered protons. In contrast, the photon-pomeron (pomeron-photon) mechanism dominates at midrapidities but the related cross section is rather small. In comparison the virtual-omega-rescattering mechanism contributes at smaller angles of photons (larger photon rapidities). Photons in the forward/backward region can be measured by the Zero Degree Calorimeters installed in experiments at the LHC while the midrapidity photons are difficult to measure (small cross section, small photon transverse momenta). Protons could be measured by the ALFA detector (ATLAS) or TOTEM detector at CMS. The exclusivity could be checked with the help of main central detectors.

  8. Minimal natural supersymmetry after the LHC8

    NASA Astrophysics Data System (ADS)

    Drees, Manuel; Kim, Jong Soo

    2016-05-01

    In this work, we present limits on natural supersymmetry scenarios based on searches in data taken during run 1 of the LHC. We consider a set of 22 000 model points in a six dimensional parameter space. These scenarios are minimal in the sense of only keeping those superparticles relatively light that are required to cancel the leading quadratically divergent quantum corrections (from the top and QCD sector) to the Higgs mass in the Standard Model. The resulting mass spectra feature Higgsinos as the lightest supersymmetric particle, as well as relatively light third generation S U (2 ) doublet squarks and S U (2 ) singlet stops and gluinos while assuming a Standard-Model-like Higgs boson. All remaining supersymmetric particles and Higgs bosons are assumed to be decoupled. We check each parameter set against a large number of LHC searches as implemented in the public code CheckMATE. These searches show a considerable degree of complementarity, i.e., in general, many searches have to be considered in order to check whether a given scenario is allowed. We delineate allowed and excluded regions in parameter space. For example, we find that all scenarios where either mt˜1<230GeV or mg ˜<440 GeV are clearly excluded, while all model points where mt ˜1>660 GeV and mg ˜>1180 GeV remain allowed.

  9. Odd top partners at the LHC

    NASA Astrophysics Data System (ADS)

    Anandakrishnan, Archana; Collins, Jack H.; Farina, Marco; Kuflik, Eric; Perelstein, Maxim

    2016-04-01

    LHC searches for fermionic top partners T focus on three decay topologies: T →b W , T →t Z , and T →t h . However, top partners may carry new conserved quantum numbers that forbid these decays. The simplest possibility is a conserved parity, under which the top partner is odd and all SM states are even. In this case, decays of top partners may involve new particle-odd scalars, leading to signal topologies more commonly associated with supersymmetry, either with or without R -parity conservation. We study a simplified model in which this possibility is realized, and estimate the bounds on the top partner mass in this model implied by LHC searches for supersymmetry. We find that the bounds can be significantly weaker than in the conventional top partner decay scenario. For example, if the new parity is exact, a 500 GeV top partner is allowed as long as the lightest parity-odd scalar mass is between 325 and 500 GeV. The lower allowed top partner mass reduces the need for fine-tuning in the Higgs mass parameter, compared to the conventional decay scenario. We also present an explicit model, the oddest little Higgs, which exhibits this phenomenology.

  10. Medical Imaging Inspired Vertex Reconstruction at LHC

    NASA Astrophysics Data System (ADS)

    Hageböck, S.; von Toerne, E.

    2012-12-01

    Three-dimensional image reconstruction in medical applications (PET or X-ray CT) utilizes sophisticated filter algorithms to linear trajectories of coincident photon pairs or x-rays. The goal is to reconstruct an image of an emitter density distribution. In a similar manner, tracks in particle physics originate from vertices that need to be distinguished from background track combinations. In this study it is investigated if vertex reconstruction in high energy proton collisions may benefit from medical imaging methods. A new method of vertex finding, the Medical Imaging Vertexer (MIV), is presented based on a three-dimensional filtered backprojection algorithm. It is compared to the open-source RAVE vertexing package. The performance of the vertex finding algorithms is evaluated as a function of instantaneous luminosity using simulated LHC collisions. Tracks in these collisions are described by a simplified detector model which is inspired by the tracking performance of the LHC experiments. At high luminosities (25 pileup vertices and more), the medical imaging approach finds vertices with a higher efficiency and purity than the RAVE “Adaptive Vertex Reconstructor” algorithm. It is also much faster if more than 25 vertices are to be reconstructed because the amount of CPU time rises linearly with the number of tracks whereas it rises quadratically for the adaptive vertex fitter AVR.

  11. Electroweak Corrections at the LHC with MCFM

    SciTech Connect

    Campbell, John M.; Wackeroth, Doreen; Zhou, Jia

    2015-07-10

    Electroweak (EW) corrections at the LHC can be enhanced at high energies due to soft/collinear radiation of W and Z bosons, being dominated by Sudakov-like corrections in the form of $\\alpha_W^l\\log^n(Q^2/M_W^2)$ $(n \\le 2l, \\alpha_W = \\alpha/(4\\pi\\sin\\theta_W^2))$ when the energy scale $Q$ enters the TeV regime. Thus, the inclusion of EW corrections in LHC predictions is important for the search of possible signals of new physics in tails of kinematic distributions. EW corrections should also be taken into account in virtue of their comparable size ($\\mathcal{O}(\\alpha)$) to that of higher order QCD corrections ($\\mathcal{O}(\\alpha_s^2)$). We calculated the next-to-leading-order (NLO) weak corrections to the neutral-current (NC) Drell-Yan process, top-quark pair production and di-jet producion, and implemented them in the Monte-Carlo program MCFM. This enables a combined study with the corresponding NLO QCD corrections. We provide both the full NLO weak corrections and their weak Sudakov approximation valid at high energies. The latter is often used for a fast evaluation of weak effects, and having the exact result available as well allows to quantify the validity of the Sudakov approximation.

  12. Strongly coupled fourth generation at the LHC

    SciTech Connect

    Burdman, G.; Da Rold, L.; Eboli, O. J. P.; Matheus, R. D.

    2009-04-01

    We study extensions of the standard model with a strongly coupled fourth generation. This occurs in models where electroweak symmetry breaking is triggered by the condensation of at least some of the fourth-generation fermions. With focus on the phenomenology at the LHC, we study the pair production of fourth-generation down quarks, D{sub 4}. We consider the typical masses that could be associated with a strongly coupled fermion sector, in the range (300-600) GeV. We show that the production and successive decay of these heavy quarks into final states with same-sign dileptons, trileptons, and four leptons can be easily seen above background with relatively low luminosity. On the other hand, in order to confirm the presence of a new strong interaction responsible for fourth-generation condensation, we study its contribution to D{sub 4} pair production, and the potential to separate it from standard QCD-induced heavy quark production. We show that this separation might require large amounts of data. This is true even if it is assumed that the new interaction is mediated by a massive colored vector boson, since its strong coupling to the fourth generation renders its width of the order of its mass. We conclude that, although this class of models can be falsified at early stages of the LHC running, its confirmation would require high integrated luminosities.

  13. Flight Day 2 Highlights

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The STS-107 second flight day begins with a shot of the Spacehab Research Double Module. Live presentations of experiments underway inside of the Spacehab Module are presented. Six experiments are shown. As part of the Space Technology and Research Student Payload, students from Australia, China, Israel, Japan, New York, and Liechtenstein are studying the effect that microgravity has on ants, spiders, silkworms, fish, bees, granular materials, and crystals. Mission Specialist Kalpana Chawla is seen working with the zeolite crystal growth experiment.

  14. Dick Crane's California Days

    NASA Astrophysics Data System (ADS)

    Holbrow, Charles H.

    2011-03-01

    Horace Richard Crane (1907-2007) was born and educated in California. His childhood was full of activities that helped him become an outstanding experimental physicist. As a graduate student at the California Institute of Technology (1930-1934), he had the good fortune to work with Charles C. Lauritsen (1892-1968) just as he introduced accelerator-based nuclear physics to Caltech. They shared the euphoric excitement of opening up a new field with simple, ingenious apparatus and experiments. This work prepared Crane for his career at the University of Michigan (1935-1973) where in the 1950s, after making the first measurement of the electron's magnetic moment, he devised the g-2 technique and made the first measurement of the anomaly in the electron's magnetic moment. A man of direct, almost laconic style, he made lasting contributions to the exposition of physics to the general public and to its teaching in high schools, community colleges, four-year colleges, and universities. I tell how he became a physicist and describe some of his early achievements.

  15. Spin and diffractive physics with a fixed-target experiment at the LHC (AFTER-LHC)

    SciTech Connect

    Lorce, C.; Chambert, V.; Didelez, J. P.; Genolini, B.; Hadjidakis, C.; Lansberg, J. P.; Rosier, P.; Brodsky, S. J.; Ferreiro, E. G.; Fleuret, F.

    2013-04-15

    We report on the spin and diffractive physics at a future multi-purpose f xed-target experiment with proton and lead LHC beams extracted by a bent crystal. The LHC multi-TeV beams allow for the most energetic f xed-target experiments ever performed, opening new domains of particle and nuclear physics and complementing that of collider physics, in particular that of RHIC and the EIC projects. The luminosity achievable with AFTER using typical targets would surpass that of RHIC by more than 3 orders of magnitude. The f xed-target mode has the advantage to allow for measurements of single-spin asymmetries with polarized target as well as of single-diffractive processes in the target region.

  16. Post-LHC8 supersymmetry benchmark points for ILC physics

    NASA Astrophysics Data System (ADS)

    Baer, Howard; List, Jenny

    2013-09-01

    We reevaluate prospects for supersymmetry (SUSY) at the proposed International Linear e+e- Collider (ILC) in light of the first two years of serious data taking at LHC: LHC7 with ˜5fb-1 of pp collisions at s=7TeV and LHC8 with ˜20fb-1 at s=8TeV. Strong new limits from LHC8 SUSY searches, along with the discovery of a Higgs boson with mh≃125GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. After a review of the current status of supersymmetry, we present a variety of new ILC benchmark models, including natural SUSY, radiatively driven natural SUSY, NUHM2 with low mA, a focus point case from mSUGRA/CMSSM, nonuniversal gaugino mass model, τ˜ coannihilation, Kallosh-Linde/spread SUSY model, mixed gauge-gravity mediation, normal scalar mass hierarchy, and one example with the recently discovered Higgs boson being the heavy CP-even state H. While all these models at present elude the latest LHC8 limits, they do offer intriguing case study possibilities for ILC operating at s≃0.25-1TeV. The benchmark points also present a view of the widely diverse SUSY phenomena which might still be expected in the post-LHC8 era at both LHC and ILC.

  17. One Cold Autumn Day

    PubMed Central

    de Schweinitz, Peter

    2015-01-01

    Behavioral change is at the heart of effective primary care, but when patients don’t change, how do we account for our days? In this personal essay, I relate an encounter with a patient who wants to quit smoking, lose weight, and control her diabetes. I am discouraged when she deflects my recommendations, but a colleague’s comment encourages a deeper inquiry. Knowing the patient’s story and deepening the conversation, however, do not guarantee change. The experience reminds me why patience, humility, and faith are core values of the primary care physician. PMID:25964410

  18. Preventing 30-day readmissions.

    PubMed

    Stevens, Sherri

    2015-03-01

    Preventing 30-day readmissions to hospitals is a top priority in the era of health care reform. New regulations will be costly to health care facilities because of payment guidelines. The most frequently readmitted medical conditions are acute myocardial infarction, heart failure, and pneumonia. The transition from the hospital and into the home has been classified as a vulnerable time for many patients. During this time of transition patients may fail to fully understand their discharge instructions. Ineffective communication, low health literacy, and compliance issues contribute to readmissions. Telehealth and the use of technology may be used to prevent some readmissions. PMID:25680492

  19. EXOTIC MAGNETS FOR ACCELERATORS.

    SciTech Connect

    WANDERER, P.

    2005-09-18

    Over the last few years, several novel magnet designs have been introduced to meet the requirements of new, high performance accelerators and beam lines. For example, the FAIR project at GSI requires superconducting magnets ramped at high rates ({approx} 4 T/s) in order to achieve the design intensity. Magnets for the RIA and FAIR projects and for the next generation of LHC interaction regions will need to withstand high doses of radiation. Helical magnets are required to maintain and control the polarization of high energy protons at RHIC. In other cases, novel magnets have been designed in response to limited budgets and space. For example, it is planned to use combined function superconducting magnets for the 50 GeV proton transport line at J-PARC to satisfy both budget and performance requirements. Novel coil winding methods have been developed for short, large aperture magnets such as those used in the insertion region upgrade at BEPC. This paper will highlight the novel features of these exotic magnets.

  20. Spatial and temporal beam profiles for the LHC using synchrotron light

    NASA Astrophysics Data System (ADS)

    Jeff, A.; Bart Pedersen, S.; Boccardi, A.; Bravin, E.; Fisher, A. S.; Guerrero Ollacarizqueta, A.; Lefevre, T.; Rabiller, A.; Welsch, C. P.

    2010-04-01

    Synchrotron radiation is emitted whenever a beam of charged particles passes though a magnetic field. The power emitted is strongly dependent on the relativistic Lorentz factor of the particles, which itself is proportional to the beam energy and inversely proportional to the particle rest mass. Thus, synchrotron radiation is usually associated with electron accelerators, which are commonly used as light sources. However the largest proton machines reach sufficiently high energies to make synchrotron light useful for diagnostic purposes. The Large Hadron Collider at CERN will accelerate protons up to an energy of 7TeV. An optical arrangement has been made which focuses synchrotron light from two LHC magnets to image the cross-section of the beam. It is also planned to use this setup to produce a longitudinal profile of the beam by use of fast Single Photon Counting. This is complicated by the bunched nature of the beam which needs to be measured with a very large dynamic range. In this contribution we present early experimental data of the transverse LHC beam profile together with a scheme for measuring the longitudinal profile with a time resolution of 50 ps. It includes the use of a gating regime to increase the dynamic range of the photon counter and a three-stage correction algorithm to compensate for the detector's deadtime, afterpulsing and pile-up effects.

  1. Three-day fever.

    PubMed

    Akakpo, A J

    2015-08-01

    Three-day fever is a viral disease caused by an Ephemerovirus of the family Rhabdoviridae, transmitted by arthropod vectors. It is common in tropical and sub-tropical regions, where it affects mainly domestic cattle and buffaloes, especially in intensive dairy or fattening production systems. It is of economic importance because it reduces milk production and fertility and causes abortion. The disease is generally benign. It manifests in several susceptible subjects simultaneously, with a sudden episode of fever accompanied by muscle involvement with arthritis, stiffness of the limbs, and lameness, followed by rapid recovery. The presence of a serofibrinous exudate in the joints is indicative of the disease. Clinical diagnosis is often difficult in the absence of pathognomonic signs. Epidemiological factors (proliferation of arthropod vectors), associated with a short-lived fever and the presence of many immature neutrophils, point strongly to three-day fever. In the absence of any specific treatment, the symptoms are treated with antibiotics and anti-inflammatories. Medical prophylaxis currently uses live attenuated vaccines, pending the development of recombinant vaccines, which are giving promising results. PMID:26601454

  2. LHC bounds on interactions of dark matter

    SciTech Connect

    Rajaraman, Arvind; Shepherd, William; Tait, Tim M. P.; Wijangco, Alexander M.

    2011-11-01

    We derive limits on the interactions of dark matter with quarks from ATLAS null searches for jets+missing energy based on {approx}1 fb{sup -1} of integrated luminosity, using a model-insensitive effective theory framework. We find that the new limits from the LHC significantly extend limits previously derived from CDF data at the Tevatron. Translated into the parameter space of direct searches, these limits are particularly effective for {approx} GeV mass weakly interacting massive particles. Our limits indicate tension with isospin-violating models satisfying minimal flavor violation which attempt to reconcile the purported CoGeNT excess with Xenon-100, indicating that either a light mediator or nontrivial flavor structure for the dark sector is necessary for a viable reconciliation of CoGeNT with Xenon.

  3. Operational results from the LHC luminosity monitors

    SciTech Connect

    Miyamoto, R.; Ratti, A.; Matis, H.S.; Stezelberger, T.; Turner, W.C.; Yaver, H.; Bravin, E.

    2011-03-28

    The luminosity monitors for the high luminosity regions in the LHC have been operating to monitor and optimize the luminosity since 2009. The device is a gas ionization chamber inside the neutral particle absorber 140 m from the interaction point and monitors showers produced by high energy neutral particles from the collisions. It has the ability to resolve the bunch-by-bunch luminosity as well as to survive the extreme level of radiation in the nominal LHC operation. We present operational results of the device during proton and lead ion operations in 2010 and make comparisons with measurements of experiments. The Large Hadron Collider (LHC) at CERN can accelerate proton and lead ion beams to 7 TeV and 547 TeV and produce collisions of these particles. Luminosity measures performance of the LHC and is particularly important for experiments in high luminosity interaction points (IPs), ATLAS (IP1) and CMS (IP5). To monitor and optimize the luminosities of these IPs, BRAN (Beam RAte Neutral) detectors [1, 2] have been installed and operating since the beginning of the 2009 operation [3]. A neutral particle absorber (TAN) protects the D2 separation dipole from high energy forward neutral particles produced in the collisions [4]. These neutral particles produce electromagnetic and hadronic showers inside the TAN and their energy flux is proportional to the collision rate and hence to the luminosity. The BRAN detector is an Argon gas ionization chamber installed inside the TANs on both sides of the IP1 and IP5 and monitors the relative changes in the luminosity by detecting the ionization due to these showers. When the number of collisions per bunch crossing (multiplicity) is small, the shower rate inside the TAN is also proportional to the luminosity. Hence, the detector is designed to operate by measuring either the shower rate (counting mode for low and intermediate luminosities) or the average shower flux (pulse height mode for high luminosities). The detector is

  4. The LHC diphoton resonance and dark matter

    NASA Astrophysics Data System (ADS)

    Mambrini, Yann; Arcadi, Giorgio; Djouadi, Abdelhak

    2016-04-01

    A resonance with a mass of approximately 750 GeV has recently been "observed" at the LHC in its diphoton decay. If this state is not simply a statistical fluctuation which will disappear with more data, it could have important implications not only for particle physics but also for cosmology. In this note, we analyze the implications of such a resonance for the dark matter (DM). Assuming a spin-1/2 DM particle, we first verify that indeed the correct relic density can be obtained for a wide range of the particle mass and weak scale coupling, that are compatible with present data. We then show that the combination of near future direct and indirect detection experiments will allow to probe the CP-nature of the mediator resonance, i.e. discriminate whether it is a scalar or a pseudoscalar like particle.

  5. SPS Beam Steering for LHC Extraction

    SciTech Connect

    Gianfelice-Wendt, Eliana; Bartosik, Hannes; Cornelis, Karel; Norderhaug Drøsdal, Lene; Goddard, Brennan; Kain, Verena; Meddahi, Malika; Papaphilippou, Yannis; Wenninger, Jorg

    2014-07-01

    The CERN Super Proton Synchrotron accelerates beams for the Large Hadron Collider to 450 GeV. In addition it produces beams for fixed target facilities which adds complexity to the SPS operation. During the run 2012-2013 drifts of the extracted beam trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses in the LHC. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. While extensive studies are going on to understand, and possibly suppress, the source of such SPS orbit drifts the feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, by means of the interlocked correctors, is also being investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed.

  6. Symmetry restored in dibosons at the LHC?

    DOE PAGESBeta

    Brehmer, Johann; Hewett, JoAnne; Kopp, Joachim; Rizzo, Thomas; Tattersall, Jamie

    2015-10-28

    A number of LHC resonance search channels display an excess in the invariant mass region of 1.8–2.0 TeV. Among them is a 3.4σ excess in the fully hadronic decay of a pair of Standard Model electroweak gauge bosons, in addition to potential signals in the HW and dijet final states. We perform a model-independent cross-section fit to the results of all ATLAS and CMS searches sensitive to these final states. We then interpret these results in the context of the Left-Right Symmetric Model, based on the extended gauge group SU(2)L × SU(2)R × U(1)', and show that a heavy right-handedmore » gauge boson WR can naturally explain the current measurements with just a single coupling gR ~ 0.4. Thus, we discuss a possible connection to dark matter.« less

  7. Hadroproduction of heavy quarkonia at the LHC

    SciTech Connect

    Berezhnoy, A. V.; Likhoded, A. K.; Luchinsky, A. V. Poslavsky, S. V.

    2015-05-15

    The production of heavy quarkonia at the LHC is considered. It is shown that, in the case of the inclusive production of χ{sub cJ}P-wave charmonia, existing experimental data can be described upon taking into account next-to-leading corrections, a dominant contribution coming from color-singlet states. For the case of B{sub c}-meson production, it is shown that, at experimentally accessible values of the transverse momentum, power-law corrections to the cross section make a significant contribution, with the result that the cross-section ratio σ(B{sub c})/σ(B) develops a p{sub T} dependence not observed in the fragmentation regime. The case of double vector-charmonium production is also considered.

  8. On dilatons and the LHC diphoton excess

    NASA Astrophysics Data System (ADS)

    Megías, Eugenio; Pujolàs, Oriol; Quirós, Mariano

    2016-05-01

    We study soft wall models that can embed the Standard Model and a naturally light dilaton. Exploiting the full capabilities of these models we identify the parameter space that allows to pass Electroweak Precision Tests with a moderate Kaluza-Klein scale, around 2 TeV. We analyze the coupling of the dilaton with Standard Model (SM) fields in the bulk, and discuss two applications: i) Models with a light dilaton as the first particle beyond the SM pass quite easily all observational tests even with a dilaton lighter than the Higgs. However the possibility of a 125 GeV dilaton as a Higgs impostor is essentially disfavored; ii) We show how to extend the soft wall models to realize a 750 GeV dilaton that could explain the recently reported diphoton excess at the LHC.

  9. Jet measurements by ALICE at LHC

    NASA Astrophysics Data System (ADS)

    Sultanov, Rishat

    2015-12-01

    Jets are collimated sprays of particles originating from fragmentation of high energy partons produced in a hard collision. They are an important diagnostic tool in studies of the Quark Gluon Plasma (QGP). The modification of the jet fragmentation pattern and its structure is a signature for the influence of hot and dense matter on the parton fragmentation process. Jet measurements in proton-proton collisions provide a baseline for similar measurements in heavy-ion collisions, while studies in proton-nucleus system allow to estimate cold nuclear matter effects. Here we present jet studies in different colliding systems (p-p, p-Pb, Pb-Pb) performed by the ALICE collaboration at LHC energies. Results on jet spectra, cross sections, nuclear modification factors, jet structure and other kinematic observables will be presented.

  10. Lhc Data for Teachers and Students

    NASA Astrophysics Data System (ADS)

    Cecire, Kenneth

    2012-08-01

    The U.S. QuarkNet program began in 1999 to involve high school students and teachers in authentic particle physics investigations using real data. This took various forms from the use of cosmic ray detectors to Z decay exercises with Hands-on-CERN. In 2010, QuarkNet opened a new chapter with the use of real data from the LHC. In collaboration with I2U2, QuarkNet staff and select teachers developed an e-Lab and a masterclass using CMS data. This development continues with the release by the CMS collaboration of over 100,000 events for education. Students and teachers have used the CMS e-Lab and masterclass as well as the ATLAS masterclass, also with real data, with very encouraging results. Working with IPPOG, QuarkNet has made these opportunities available internationally as well as within the U.S. text.

  11. Discovering Chiral Higgsinos at the LHC

    SciTech Connect

    Arvanitaki, Asimina; /Stanford U., ITP /SLAC

    2006-11-10

    The concept of chirality is extended to the Minimal Supersymmetric Standard Model (MSSM) and the {micro} term is forbidden by a gauged U(1){prime} symmetry. R-parity automatically emerges after symmetry breaking, suppressing proton decay and protecting the LSP. Exotics charged under the SM pose a challenge to traditional SU(5) unification, but unification is still implemented in deconstructed GUTs. Because of the multitude of additional states to the MSSM, the Z{prime} has a large width, and the SM background, neglected in previous theoretical studies, becomes important for Z{prime} discovery. As a result, the LHC reach is reduced from 3.2 TeV, for a Z{prime} with SM decays, to 1.5 TeV, when additional decay channels are included. This model also predicts possibly long-lived colored and electroweak exotics.

  12. LHC diphoton resonance from gauge symmetry

    NASA Astrophysics Data System (ADS)

    Boucenna, Sofiane M.; Morisi, Stefano; Vicente, Avelino

    2016-06-01

    Motivated by what is possibly the first sign of new physics seen at the LHC, the diphoton excess at 750 GeV in ATLAS and CMS, we present a model that provides naturally the necessary ingredients to explain the resonance. The simplest phenomenological explanation for the diphoton excess requires a new scalar state, X (750 ) , as well as additional vectorlike (VL) fermions introduced in an ad-hoc way in order to enhance its decays into a pair of photons and/or increase its production cross section. We show that the necessary VL quarks and their couplings can emerge naturally from a complete framework based on the S U (3 )L⊗U (1 )X gauge symmetry.

  13. Naturalness in the dark at the LHC

    NASA Astrophysics Data System (ADS)

    Craig, Nathaniel; Katz, Andrey; Strassler, Matt; Sundrum, Raman

    2015-07-01

    We revisit the Twin Higgs scenario as a "dark" solution to the little hierarchy problem, identify the structure of a minimal model and its viable parameter space, and analyze its collider implications. In this model, dark naturalness generally leads to Hidden Valley phenomenology. The twin particles, including the top partner, are all Standard-Model-neutral, but naturalness favors the existence of twin strong interactions — an asymptotically-free force that confines not far above the Standard Model QCD scale — and a Higgs portal interaction. We show that, taken together, these typically give rise to exotic decays of the Higgs to twin hadrons. Across a substantial portion of the parameter space, certain twin hadrons have visible and often displaced decays, providing a potentially striking LHC signature. We briefly discuss appropriate experimental search strategies.

  14. Jet measurements by ALICE at LHC

    SciTech Connect

    Sultanov, Rishat; Collaboration: ALICE Collaboration

    2015-12-15

    Jets are collimated sprays of particles originating from fragmentation of high energy partons produced in a hard collision. They are an important diagnostic tool in studies of the Quark Gluon Plasma (QGP). The modification of the jet fragmentation pattern and its structure is a signature for the influence of hot and dense matter on the parton fragmentation process. Jet measurements in proton-proton collisions provide a baseline for similar measurements in heavy-ion collisions, while studies in proton-nucleus system allow to estimate cold nuclear matter effects. Here we present jet studies in different colliding systems (p–p, p–Pb, Pb–Pb) performed by the ALICE collaboration at LHC energies. Results on jet spectra, cross sections, nuclear modification factors, jet structure and other kinematic observables will be presented.

  15. A model for the LHC diboson excess

    NASA Astrophysics Data System (ADS)

    Buen-Abad, Manuel; Cohen, Andrew G.; Schmaltz, Martin

    2016-05-01

    The first run of the LHC showed hints of a new resonance with mass near 1.9 TeV decaying into electroweak gauge boson pairs as well as into dijets. While Run 2 has neither confirmed nor ruled out such a resonance, it has yielded new constraints on models attempting to explain these decays. Additionally in W' models where this new resonance is a charged vector boson that is a weak isospin singlet there is the potential for conflict with the electroweak precision T parameter. We construct variants of a W' resonance model that provide an excellent fit to both Run 1 and Run 2 data, as well as electroweak precision measurements. The model also predicts a neutral vector boson, a Z', with mass close to 3 TeV. This Z' is compatible with the intriguing Run 2 observation of a dielectron pair with invariant mass of 2.9 TeV at CMS.

  16. ADVANCES TOWARDS THE MEASUREMENT AND CONTROL LHC TUNE AND CHROMATICITY

    SciTech Connect

    CAMERON, P.; CUPOLO, J.; DEGEN, C.; DELLAPENNA, A.; HOFF, L.; MEAD, J.; SIKORA, R.

    2005-06-06

    Requirements for tune and chromaticity control in most superconducting hadron machines, and in particular the LHC, are stringent. In order to reach nominal operation, the LHC will almost certainly require feedback on both tune and chromaticity. Experience at RHIC has also shown that coupling control is crucial to successful tune feedback. A prototype baseband phase-locked loop (PLL) tune measurement system has recently been brought into operation at RHIC as part of the US LHC Accelerator Research Program (LARP). We report on the performance of that system and compare it with the extensive accumulation of data from the RHIC 245MHz PLL.

  17. New Physics Searches at the LHC: Results and Future Prospects

    NASA Astrophysics Data System (ADS)

    Liu, Hongxuan

    2015-04-01

    Over the Run 1 operation of the Large Hadron Collider (LHC), the Standard Model (SM) is completed by the discovery of the Higgs boson and has proven incredibly robust. However there are many open questions remain unanswered and the SM cannot be the whole story. Broad programs searching for new physics beyond the SM have been performed by the ATLAS and CMS experiments at the LHC using the Run 1 data. In this talk, selective searches from both experiments are presented. The future prospects from the LHC Run 2 operation will be also discussed.

  18. The NUHM2 after LHC Run 1

    DOE PAGESBeta

    Buchmueller, O.; Cavanaugh, R.; Citron, M.; De Roeck, A.; Dolan, M. J.; Ellis, J. R.; Flächer, H.; Heinemeyer, S.; Malik, S.; Marrouche, J.; et al

    2014-12-17

    We make a frequentist analysis of the parameter space of the NUHM2, in which the soft supersymmetry (SUSY)-breaking contributions to the masses of the two Higgs multiplets, m2Hu,d, vary independently from the universal soft SUSY-breaking contributions m20 to the masses of squarks and sleptons. Our analysis uses the MultiNest sampling algorithm with over 4 × 10⁸ points to sample the NUHM2 parameter space. It includes the ATLAS and CMS Higgs mass measurements as well as the ATLAS search for supersymmetric jets + /ET signals using the full LHC Run 1 data, the measurements of BR(Bs→μ⁺μ⁻) by LHCb and CMS togethermore » with other B-physics observables, electroweak precision observables and the XENON100 and LUX searches for spin-independent dark-matter scattering. We find that the preferred regions of the NUHM2 parameter space have negative SUSY-breaking scalar masses squared at the GUT scale for squarks and sleptons, m20 < 0, as well as m2Hu < m2Hd < 0. The tension present in the CMSSM and NUHM1 between the supersymmetric interpretation of (g – 2)μ and the absence to date of SUSY at the LHC is not significantly alleviated in the NUHM2. We find that the minimum χ2 = 32.5 with 21 degrees of freedom (dof) in the NUHM2, to be compared with χ2/dof = 35.0/23 in the CMSSM, and χ2/dof = 32.7/22 in the NUHM1. We find that the one-dimensional likelihood functions for sparticle masses and other observables are similar to those found previously in the CMSSM and NUHM1.« less

  19. Yukawa unification predictions for the LHC

    NASA Astrophysics Data System (ADS)

    Anandakrishnan, Archana; Raby, Stuart; Wingerter, Akın

    2013-03-01

    This paper is divided into two parts. In the first part we analyze the consequences, for the LHC, of gauge and third-family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unification scale. We perform a global χ2 analysis including the observables MW, MZ, GF, αem-1, αs(MZ), Mt, mb(mb), Mτ, BR(B→Xsγ), BR(Bs→μ+μ-), and Mh. The fit is performed in the minimal supersymmetric Standard Model in terms of nine grand unification-scale parameters, while tan⁡β and μ are fixed at the weak scale. Good fits suggest an upper bound on the gluino mass, Mg˜≲2TeV. This constraint comes predominantly from fitting the bottom-quark and Higgs masses (assuming a 125 GeV Higgs). Gluinos should be visible at the LHC in the 14 TeV run but they cannot be described by the typical simplified models. This is because the branching ratios for g˜→tt¯χ˜1,20, bb¯χ˜1,20, tb¯χ˜1,2-, bt¯χ˜1,2+, gχ˜1,2,3,40 are comparable. Top squarks and sbottoms may also be visible. Charginos and neutralinos can be light, with the lightest supersymmetric particle predominantly bino-like. In the second part of the paper we analyze a complete three-family model and discuss the quality of the global χ2 fits and the differences between the third-family analysis and the full three-family analysis for overlapping observables. We note that the light Higgs in our model couples to matter like the Standard Model Higgs. Any deviation from this would rule out this model.

  20. Probing (g -2 )μ at the LHC in the paradigm of R -parity violating MSSM

    NASA Astrophysics Data System (ADS)

    Chakraborty, Amit; Chakraborty, Sabyasachi

    2016-04-01

    The measurement of the anomalous magnetic moment of the muon exhibits a long-standing discrepancy compared to the standard model prediction. In this paper, we concentrate on this issue in the framework of the R -parity violating minimal supersymmetric standard model. Such a scenario provides a substantial contribution to the anomalous magnetic moment of the muon while satisfying constraints from low energy experimental observables as well as the neutrino mass. In addition, we point out that the implication of such operators satisfying muon g -2 are immense from the perspective of the LHC experiment, leading to a spectacular four muon final state. We propose an analysis in this particular channel which might help to settle the debate of R -parity violation as a probable explanation for (g -2 )μ.

  1. World AIDS Day 1998.

    PubMed

    1999-01-01

    Excerpts of speeches given at a public rally on World AIDS Day 1998 underscore the need to energize support for those living with HIV/AIDS, emphasize the importance of increasing public education efforts, and memorialize those lost to the disease. Reverend Pat Bumgardner stressed the need to educate children about practicing safe sex and the dangers of drug use. He also focused attention on AIDS as a worldwide crisis, with the 30 million people who have HIV or AIDS. Councilwoman Margarita Lopez spoke about achieving objectives and securing resources through activism. She also condemned New York City's Mayor for trying to hinder the rally. Anne Chelimsky, who did not speak at the rally but attended it, reflected on her new role as an activist, and on how the rally affected her. PMID:11367196

  2. Proceedings, Dean's Day 1999

    SciTech Connect

    Zanner, M.A.

    1999-03-01

    On January 14--15, 1999, Sandia National Laboratories sponsored Deans Day, a conference for the Deans of Engineering and other executive-level representatives from 29 invited universities. Through breakout sessions and a wrap-up discussion, university and Sandia participants identified activities to further develop their strategic relationships. The four primary activities are: (A) concentrate joint efforts on current and future research strengths and needs; (B) attract the best students (at all grade levels) to science and engineering; (C) promote awareness of the need for and work together to influence a national science and technology R and D policy; and (D) enable the universities and Sandia to be true allies, jointly pursuing research opportunities and funding from government agencies and industry.

  3. Perspectives on Infant Day Care.

    ERIC Educational Resources Information Center

    Elardo, Richard, Ed.; Pagan, Betty, Ed.

    This second edition contains articles on (1) infant day care, (2) day care as a way to extend parental support systems, (3) meeting developmental needs of infants, (4) ecology of day care, (5) ecology of infant day care, (6) quality care for infants, (7) the daily schedule, (8) precautions in establishing infant day care, (9) teaching--learning…

  4. 5-year operation experience with the 1.8 K refrigeration units of the LHC cryogenic system

    NASA Astrophysics Data System (ADS)

    Ferlin, G.; Tavian, L.; Claudet, S.; Pezzetti, M.

    2015-12-01

    Since 2009, the Large Hadron Collider (LHC) is in operation at CERN. The LHC superconducting magnets distributed over eight sectors of 3.3-km long are cooled at 1.9 K in pressurized superfluid helium. The nominal operating temperature of 1.9 K is produced by eight 1.8-K refrigeration units based on centrifugal cold compressors (3 or 4 stages depending to the vendor) combined with warm volumetric screw compressors with sub-atmospheric suction. After about 5 years of continuous operation, we will present the results concerning the availability for the final user of these refrigeration units and the impact of the design choice on the recovery time after a system trip. We will also present the individual results for each rotating machinery in terms of failure origin and of Mean Time between Failure (MTBF), as well as the consolidations and upgrades applied to these refrigeration units.

  5. Selected experimental results from heavy-ion collisions at LHC

    DOE PAGESBeta

    Singh, Ranbir; Kumar, Lokesh; Netrakanti, Pawan Kumar; Mohanty, Bedangadas

    2013-01-01

    We reviewmore » a subset of experimental results from the heavy-ion collisions at the Large Hadron Collider (LHC) facility at CERN. Excellent consistency is observed across all the experiments at the LHC (at center of mass energysNN=2.76 TeV) for the measurements such as charged particle multiplicity density, azimuthal anisotropy coefficients, and nuclear modification factor of charged hadrons. Comparison to similar measurements from the Relativistic Heavy Ion Collider (RHIC) at lower energy (sNN=200 GeV) suggests that the system formed at LHC has a higher energy density and larger system size and lives for a longer time. These measurements are compared to model calculations to obtain physical insights on the properties of matter created at the RHIC and LHC.« less

  6. Can we see tau-Flavour Violation at the LHC?

    SciTech Connect

    Carquin, E.; Gomez, M. E.; Rodriguez-Quintero, J.

    2010-02-10

    We study the conditions required for chi{sub 2}->chi+tau{sup +}-mu{sup +}- decays to yield observable tau flavour violation at the LHC, for cosmologically interesting values of the neutralino relic density.

  7. Electroweak contributions to squark pair production at the LHC

    SciTech Connect

    Germer, Jan; Hollik, Wolfgang; Mirabella, Edoardo; Trenkel, Maike

    2010-02-10

    We present the tree-level and next-to-leading order (NLO) electroweak (EW) contributions to squark - squark production at the Large Hadron Collider (LHC) within the framework of the Minimal Supersymmetric Standard Model (MSSM).

  8. Operating the Worldwide LHC Computing Grid: current and future challenges

    NASA Astrophysics Data System (ADS)

    Flix Molina, J.; Forti, A.; Girone, M.; Sciaba, A.

    2014-06-01

    The Wordwide LHC Computing Grid project (WLCG) provides the computing and storage resources required by the LHC collaborations to store, process and analyse their data. It includes almost 200,000 CPU cores, 200 PB of disk storage and 200 PB of tape storage distributed among more than 150 sites. The WLCG operations team is responsible for several essential tasks, such as the coordination of testing and deployment of Grid middleware and services, communication with the experiments and the sites, followup and resolution of operational issues and medium/long term planning. In 2012 WLCG critically reviewed all operational procedures and restructured the organisation of the operations team as a more coherent effort in order to improve its efficiency. In this paper we describe how the new organisation works, its recent successes and the changes to be implemented during the long LHC shutdown in preparation for the LHC Run 2.

  9. Black Holes at the LHC: Progress since 2002

    SciTech Connect

    Park, Seong Chan

    2008-11-23

    We review the recent noticeable progresses in black hole physics focusing on the up-coming super-collider, the LHC. We discuss the classical formation of black holes by particle collision, the greybody factors for higher dimensional rotating black holes, the deep implications of black hole physics to the 'energy-distance' relation, the security issues of the LHC associated with black hole formation and the newly developed Monte-Carlo generators for black hole events.

  10. Unitarity bounds on scalar dark matter effective interactions at LHC

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yasuhiro

    2014-12-01

    We have investigated the compatibility of the unitarity bound and the 8 TeV LHC on the effective theory of scalar dark matter. In several signals of effective interactions, monojet events with missing energy were studied. We found that if the dark matter mass is about 800 GeV or heavier, the contributions of events violating unitarity are not negligible. The unitarity conditions in the 14 TeV LHC are also calculated.

  11. Some aspects of Physics beyond the Standard Model at LHC

    NASA Astrophysics Data System (ADS)

    Casas, J. Alberto

    2014-03-01

    The LHC is constraining BSM physics at an impressive efficience, but no sign of new physics has been found yet. SUSY (and other BSM scenarios) are starting to be in trouble, though there is still room for new physics able to solve the Hierarchy Problem. This situation poses new challenges to optimize the LHC discovery potential using smarter strategies for analysis. In this sense, direct and indirect searches of new physics can play complementary roles.

  12. Accounting for soft cross sections at the LHC

    SciTech Connect

    Gotsman, Errol

    2013-04-15

    We describe briefly the elements of the GLM model that successfully describes soft hadronic interactions at energies from ISR to LHC. This model is based on a single Pomeron with a large intercept {Delta}{sub IP}= 0.23 and slope {alpha} Prime {sub IP}= 0, and so provides a natural matching with perturbative QCD. We summarize themain features and results of competing models for soft interactions at LHC energies.

  13. Preparing ATLAS reconstruction software for LHC's Run 2

    NASA Astrophysics Data System (ADS)

    Mitrevski, Jovan

    2015-12-01

    In order to maximize the physics potential of the ATLAS experiment during LHC's Run 2, the reconstruction software has been updated. Flat computing budgets required a factor of three improved execution time, while the new xAOD data format forced changes in the reconstruction algorithms. Physics performance was also made better. This paper presents an overview of the improvements made to the reconstruction software during the long shutdown of the LHC.

  14. Predictions of exclusive ψ(2S) production at the LHC

    NASA Astrophysics Data System (ADS)

    Jones, S. P.; Martin, A. D.; Ryskin, M. G.; Teubner, T.

    2014-05-01

    The cross section for exclusive ψ(2S) ultraperipheral production at the LHC is calculated using gluon parametrizations extracted from exclusive J/ψ measurements performed at HERA and the LHC. Predictions are given at leading and next-to-leading order for pp centre-of-mass energies of 7, 8 and 14 TeV, assuming the non-relativistic approximation for the ψ(2S) wave function.

  15. SUSY searches at the LHC with the ATLAS experiment

    ScienceCinema

    None

    2011-04-25

    First ATLAS searches for signals of Supersymmetry in proton-proton collisions at the LHC are presented. These searches are performed in various channels containing different lepton and jet multiplicities in the final states; the full data sample recorded in the 2010 LHC run, corresponding to an integrated luminosity of 35 pb-1, has been analysed. Limits on squarks and gluins are the most stringent to date.

  16. AAS 227: Day 3

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Editors Note:This week were at the 227th AAS Meeting in Kissimmee, FL. Along with several fellow authors from astrobites.com, I will bewritingupdates on selectedevents at themeeting and posting at the end of each day. Follow along here or atastrobites.com, or catch ourlive-tweeted updates from the@astrobites Twitter account. The usual posting schedule for AAS Nova will resumenext week.Welcome to Day 3 of the winter American Astronomical Society (AAS) meeting in Kissimmee! Several of us are attending the conference this year, and we will report highlights from each day here on astrobites. If youd like to see more timely updates during the day, we encourage you to follow @astrobites on twitter or search the #aas227 hashtag.Henry Norris Russell Lecture: Viewing the Universe with Infrared Eyes: The Spitzer Space Telescope (by Erika Nesvold)The Henry Norris Russell Award is the highest honor given by the AAS, for a lifetime of eminence in astronomy research. This years award went to Giovanni Fazio of the Harvard-Smithsonian Center for Astrophysics. Fazio became a leader in gamma ray astronomy before switching mid-career to the study of infrared astronomy, and he gave his award lecture on the latter subject, specifically on the Spitzer Space Telescope, one of the most successful infrared telescopes of all time.Artists rendering of the Spitzer space telescope. [NASA/JPL-Caltech]Spitzer has been operating for more than twelve years, and has resulted in over six thousand papers in refereed journals in that time. The telescope sits in an Earth-trailing orbit around the Sun, and is now farther from the Earth (1.4 AU) than the Earth is from the Sun. Fazio gave the audience a fascinating overview of the science done by Spitzer over more than a decade. One of the most productive areas of research for Spitzer is the study of exoplanets, which hadnt even been discovered when the Spitzer Telescope was first conceived. Spitzers high sensitivity and ability to observe exoplanets over

  17. Day-1 chick development.

    PubMed

    Sheng, Guojun

    2014-03-01

    The first day of chick development takes place inside the mother hen (in utero), during which the embryo progresses from fertilization to late blastula/early gastrula formation. The salient features of developmental anatomy in this period are conserved among the sauropsids (birds and reptiles). Many of these features are also shared in prototherian (monotreme) embryos, whereas metatherian (marsupial) and eutherian (placental) embryos display significant variations. Important for understanding the evolution of early development in amniotes, the knowledge of cellular and molecular mechanisms regulating in utero chick development may also offer valuable insight into early lineage specification in prototherians and conserved features in mammalian early development. This commentary provides a snapshot of what is currently known about intrauterine chick development and identifies key issues that await further clarification, including the process of cellularization, allocation of maternal determinants, zygotic gene activation, mid-blastula transition, cell layer increase and reduction, radial symmetry breaking, early lineage segregation, and role of yolk syncytium in early patterning. PMID:24550174

  18. AAS 227: Day 4

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Editors Note:This week were at the 227th AAS Meeting in Kissimmee, FL. Along with several fellow authors from astrobites.com, I will bewritingupdates on selectedevents at themeeting and posting at the end of each day. Follow along here or atastrobites.com, or catch ourlive-tweeted updates from the@astrobites Twitter account. The usual posting schedule for AAS Nova will resumenext week.Welcome to Day 4 of the winter American Astronomical Society (AAS) meeting in Kissimmee! Several of us are attending the conference this year, and we will report highlights from each day here on astrobites. If youd like to see more timely updates during the day, we encourage you to follow @astrobites on twitter or search the #aas227 hashtag.Helen B. Warner Prize: Origins of Structure in Planetary Systems (by Erika Nesvold)Another excellent prize lecture started off todays sessions. The Helen B. Warner Prize is awarded for achievement in observational or theoretical astrophysics by a young researcher (no more than eight years after their Ph.D.). This years Warner Prize was presented to Ruth Murray-Clay of UC Santa Barbara. For her award lecture, Murray-Clay told us all about planetary system architecture: the number, masses, and orbits of planets in a given system.Ruth Murray-Clay [photo from http://web.physics.ucsb.edu/ ~murray/biocv.html]The underlying question motivating this type of research is: How rare is the Solar System? In other words, how likely is it that a given planetary system will have rocky planets close to their star, gas giants farther out, and ice giants at the outer reaches of the system? Answering this question will help us solve the physics problem of how and where planets form, and will also help us on our search for other planets like Earth.The data on exoplanet population from transit and radial velocity observations and from direct imaging tell us that our Solar System is not common (many systems we observe have much more eccentric gas giants), but that doesnt

  19. The triple day.

    PubMed

    Smith, V

    1980-08-01

    The risks are high and the returns low when Peruvian women work outside the home, but they have few other options. Most have large families, and their husbands scramble to earn a few dollars. For some women the day begins at 3:30 a.m. when they go to Lima to peddle fish, combs, or whatever commodity is available. The poor women who live in the pueblos jovenes of Lima, the newly formed outskirts, have banded together in a Christian group called Luz y Esperanza, or Light and Hope. The group has a 10-year history of coping with unsanitary water and resultant health problems, child care, and lack of electricity. The women began with neighborhood issues but have also developed an interest in trade unions and other less local concerns. Members have also started to attend union meetings in Lima and involved themselves in recent trade union struggles. The development of the women's political consciousness is closely intertwined with their Christian faith. They believe Christ is the source of the energy they need to persevere. PMID:12262074

  20. Geometric beam coupling impedance of LHC secondary collimators

    NASA Astrophysics Data System (ADS)

    Frasciello, Oscar; Tomassini, Sandro; Zobov, Mikhail; Salvant, Benoit; Grudiev, Alexej; Mounet, Nicolas

    2016-02-01

    The High Luminosity LHC project is aimed at increasing the LHC luminosity by an order of magnitude. One of the key ingredients to achieve the luminosity goal is the beam intensity increase. In order to keep beam instabilities under control and to avoid excessive power losses a careful design of new vacuum chamber components and an improvement of the present LHC impedance model are required. Collimators are among the major impedance contributors. Measurements with beam have revealed that the betatron coherent tune shifts were higher by about a factor of 2 with respect to the theoretical predictions based on the LHC impedance model up to 2012. In that model the resistive wall impedance has been considered as the dominating impedance contribution for collimators. By carefully simulating also their geometric impedance we have contributed to the update of the LHC impedance model, reaching also a better agreement between the measured and simulated betatron tune shifts. During the just ended LHC Long Shutdown I (LSI), TCS/TCT collimators were replaced by new devices embedding BPMs and TT2-111R ferrite blocks. We present here preliminary estimations of their broad-band impedance, showing that an increase of about 20% is expected in the kick factors with respect to previous collimators without BPMs.

  1. CERN database services for the LHC computing grid

    NASA Astrophysics Data System (ADS)

    Girone, M.

    2008-07-01

    Physics meta-data stored in relational databases play a crucial role in the Large Hadron Collider (LHC) experiments and also in the operation of the Worldwide LHC Computing Grid (WLCG) services. A large proportion of non-event data such as detector conditions, calibration, geometry and production bookkeeping relies heavily on databases. Also, the core Grid services that catalogue and distribute LHC data cannot operate without a reliable database infrastructure at CERN and elsewhere. The Physics Services and Support group at CERN provides database services for the physics community. With an installed base of several TB-sized database clusters, the service is designed to accommodate growth for data processing generated by the LHC experiments and LCG services. During the last year, the physics database services went through a major preparation phase for LHC start-up and are now fully based on Oracle clusters on Intel/Linux. Over 100 database server nodes are deployed today in some 15 clusters serving almost 2 million database sessions per week. This paper will detail the architecture currently deployed in production and the results achieved in the areas of high availability, consolidation and scalability. Service evolution plans for the LHC start-up will also be discussed.

  2. AAS 227: Day 4

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Editors Note:This week were at the 227th AAS Meeting in Kissimmee, FL. Along with several fellow authors from astrobites.com, I will bewritingupdates on selectedevents at themeeting and posting at the end of each day. Follow along here or atastrobites.com, or catch ourlive-tweeted updates from the@astrobites Twitter account. The usual posting schedule for AAS Nova will resumenext week.Welcome to Day 4 of the winter American Astronomical Society (AAS) meeting in Kissimmee! Several of us are attending the conference this year, and we will report highlights from each day here on astrobites. If youd like to see more timely updates during the day, we encourage you to follow @astrobites on twitter or search the #aas227 hashtag.Helen B. Warner Prize: Origins of Structure in Planetary Systems (by Erika Nesvold)Another excellent prize lecture started off todays sessions. The Helen B. Warner Prize is awarded for achievement in observational or theoretical astrophysics by a young researcher (no more than eight years after their Ph.D.). This years Warner Prize was presented to Ruth Murray-Clay of UC Santa Barbara. For her award lecture, Murray-Clay told us all about planetary system architecture: the number, masses, and orbits of planets in a given system.Ruth Murray-Clay [photo from http://web.physics.ucsb.edu/ ~murray/biocv.html]The underlying question motivating this type of research is: How rare is the Solar System? In other words, how likely is it that a given planetary system will have rocky planets close to their star, gas giants farther out, and ice giants at the outer reaches of the system? Answering this question will help us solve the physics problem of how and where planets form, and will also help us on our search for other planets like Earth.The data on exoplanet population from transit and radial velocity observations and from direct imaging tell us that our Solar System is not common (many systems we observe have much more eccentric gas giants), but that doesnt

  3. The PDF4LHC report on PDFs and LHC data: results from Run I and preparation for Run II

    NASA Astrophysics Data System (ADS)

    Rojo, Juan; Accardi, Alberto; Ball, Richard D.; Cooper-Sarkar, Amanda; de Roeck, Albert; Farry, Stephen; Ferrando, James; Forte, Stefano; Gao, Jun; Harland-Lang, Lucian; Huston, Joey; Glazov, Alexander; Gouzevitch, Maxime; Gwenlan, Claire; Lipka, Katerina; Lisovyi, Mykhailo; Mangano, Michelangelo; Nadolsky, Pavel; Perrozzi, Luca; Plačakytė, Ringaile; Radescu, Voica; Salam, Gavin P.; Thorne, Robert

    2015-10-01

    The accurate determination of the parton distribution functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson characterization and precision Standard Model measurements to new physics searches. A major recent development in modern PDF analyses has been to exploit the wealth of new information contained in precision measurements from the LHC Run I, as well as progress in tools and methods to include these data in PDF fits. In this report we summarize the information that PDF-sensitive measurements at the LHC have provided so far, and review the prospects for further constraining PDFs with data from the recently started Run II. This document aims to provide useful input to the LHC collaborations to prioritize their PDF-sensitive measurements at Run II, as well as a comprehensive reference for the PDF-fitting collaborations.

  4. The PDF4LHC report on PDFs and LHC data: Results from Run I and preparation for Run II

    DOE PAGESBeta

    Rojo, Juan; Accardi, Alberto; Ball, Richard D.; Cooper-Sarkar, Amanda; de Roeck, Albert; Farry, Stephen; Ferrando, James; Forte, Stefano; Gao, Jun; Harland-Lang, Lucian; et al

    2015-09-16

    The accurate determination of Parton Distribution Functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson characterization and precision Standard Model measurements to New Physics searches. A major recent development in modern PDF analyses has been to exploit the wealth of new information contained in precision measurements from the LHC Run I, as well as progress in tools and methods to include these data in PDF fits. In this report we summarize the information that PDF-sensitive measurements at the LHC have provided somore » far, and review the prospects for further constraining PDFs with data from the recently started Run II. As a result, this document aims to provide useful input to the LHC collaborations to prioritize their PDF-sensitive measurements at Run II, as well as a comprehensive reference for the PDF-fitting collaborations.« less

  5. The PDF4LHC report on PDFs and LHC data: Results from Run I and preparation for Run II

    SciTech Connect

    Rojo, Juan; Accardi, Alberto; Ball, Richard D.; Cooper-Sarkar, Amanda; de Roeck, Albert; Farry, Stephen; Ferrando, James; Forte, Stefano; Gao, Jun; Harland-Lang, Lucian; Huston, Joey; Glazov, Alexander; Gouzevitch, Maxime; Gwenlan, Claire; Lipka, Katerina; Lisovyi, Mykhailo; Mangano, Michelangelo; Nadolsky, Pavel; Perrozzi, Luca; Plačakytė, Ringaile; Radescu, Voica; Salam, Gavin P.; Thorne, Robert

    2015-09-16

    The accurate determination of Parton Distribution Functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson characterization and precision Standard Model measurements to New Physics searches. A major recent development in modern PDF analyses has been to exploit the wealth of new information contained in precision measurements from the LHC Run I, as well as progress in tools and methods to include these data in PDF fits. In this report we summarize the information that PDF-sensitive measurements at the LHC have provided so far, and review the prospects for further constraining PDFs with data from the recently started Run II. As a result, this document aims to provide useful input to the LHC collaborations to prioritize their PDF-sensitive measurements at Run II, as well as a comprehensive reference for the PDF-fitting collaborations.

  6. AAS 227: Day 3

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Editors Note:This week were at the 227th AAS Meeting in Kissimmee, FL. Along with several fellow authors from astrobites.com, I will bewritingupdates on selectedevents at themeeting and posting at the end of each day. Follow along here or atastrobites.com, or catch ourlive-tweeted updates from the@astrobites Twitter account. The usual posting schedule for AAS Nova will resumenext week.Welcome to Day 3 of the winter American Astronomical Society (AAS) meeting in Kissimmee! Several of us are attending the conference this year, and we will report highlights from each day here on astrobites. If youd like to see more timely updates during the day, we encourage you to follow @astrobites on twitter or search the #aas227 hashtag.Henry Norris Russell Lecture: Viewing the Universe with Infrared Eyes: The Spitzer Space Telescope (by Erika Nesvold)The Henry Norris Russell Award is the highest honor given by the AAS, for a lifetime of eminence in astronomy research. This years award went to Giovanni Fazio of the Harvard-Smithsonian Center for Astrophysics. Fazio became a leader in gamma ray astronomy before switching mid-career to the study of infrared astronomy, and he gave his award lecture on the latter subject, specifically on the Spitzer Space Telescope, one of the most successful infrared telescopes of all time.Artists rendering of the Spitzer space telescope. [NASA/JPL-Caltech]Spitzer has been operating for more than twelve years, and has resulted in over six thousand papers in refereed journals in that time. The telescope sits in an Earth-trailing orbit around the Sun, and is now farther from the Earth (1.4 AU) than the Earth is from the Sun. Fazio gave the audience a fascinating overview of the science done by Spitzer over more than a decade. One of the most productive areas of research for Spitzer is the study of exoplanets, which hadnt even been discovered when the Spitzer Telescope was first conceived. Spitzers high sensitivity and ability to observe exoplanets over

  7. International Women's Day speech.

    PubMed

    Kazibwe, S W

    1993-01-01

    The objectives of the International Women's Day are: 1) to celebrate the struggle for women's rights in the economic, social, political, and cultural domain; 2) to reaffirm women's solidarity in the struggle for peace; 3) and to show what women have achieved. In 1988, Uganda's government of the National Resistance Movement created the Ministry of Women in Development. The period 1988-1990 was one of consultations, needs assessment, planning, and recruiting staff for the Ministry. From 1990 to 1993, measurable results have been achieved. The Ministry's gender concerns pertained to the sector policies of the Ministries of Agriculture, Animal Industry and Fisheries, Education, Health, Water, Energy, Minerals, and Environment Protection. Under the Umbrella Project for Women in Development, gender sensitization has been achieved with policy makers in ministries, at district level, and in the media. Gender issues have also been incorporated in the National Political School Curriculum. The Ministry has also trained a corps of 73 women trainers from 38 districts. The Ministry, with funding from DANIDA, collected women's views on the constitution through meetings and seminars in all the districts in the country. Recommendations were submitted in a consolidated report to the Constitution Commission. A pilot para-legal scheme is successfully being implemented in Kamuli district. A community-based pool of legal advisors has been developed. Legal matters that affect both women and men are undertaken at the community level. The economic emancipation of women is a crucial part of the Ministry's mandate. In conjunction with NGOs, pilot credit programs are being run in Mukono, Jinja, Mbale, and Kapchorwa districts. Cross-sectoral programs are in close collaboration with the rural water and sanitation program, the Northern Uganda rehabilitation program, and the integrated Basic Education Pilot Project to be implemented in 8 districts. PMID:12345405

  8. MSSM Higgs bosons at the LHC

    NASA Astrophysics Data System (ADS)

    Christensen, Neil; Han, Tao; Su, Shufang

    2012-06-01

    The recent results on Higgs boson searches from LHC experiments provide significant guidance in exploring the minimal supersymmetric (SUSY) standard model (MSSM) Higgs sector. If we accept the existence of a SM-like Higgs boson in the mass window of 123 GeV-127 GeV as indicated by the observed γγ events, there are two distinct mass regions (in mA) left in the MSSM Higgs sector: (a) the lighter CP-even Higgs boson being SM-like and the non-SM-like Higgs bosons all heavy and nearly degenerate above 300 GeV (an extended decoupling region); (b) the heavier CP-even Higgs boson being SM-like and the neutral non-SM-like Higgs bosons all nearly degenerate around 100 GeV (a small non-decoupling region). On the other hand, due to the strong correlation between the Higgs decays to W+W- and to γγ predicted in the MSSM, the apparent absence of a W+W- final state signal is in direct conflict with the γγ peak. If we consider the W+W- channel on its own, the absence of the W+W- signal would imply that the SM-like Higgs boson has reduced coupling to W±, and that the other non-SM-like Higgs bosons should not be too heavy and do not decouple. If both the γγ excess and the absence of a W+W- signal continue, new physics beyond the MSSM will be required. A similar correlation exists between the W+W- and τ+τ- channels: a reduced W+W- channel would force the τ+τ- channel to be larger. Future searches for the SM-like Higgs boson at the LHC will provide critical tests for the MSSM prediction. We also study the signals predicted for the non-SM-like Higgs bosons and emphasize the potential importance of the electroweak processes pp→H+H-, H±A0, which are independent of the SUSY parameters except for their masses. In addition, there may be sizable contributions from pp→H±h0, A0h0 and W±H0, ZH0 in the low-mass non-decoupling region, which may serve to discriminate the model parameters. We allow variations of the relevant SUSY parameters in a broad range and demonstrate the

  9. The ATLAS liquid argon calorimeter: One year of LHC operation and future upgrade plans for HL-LHC

    SciTech Connect

    Krieger, P. W.

    2011-07-01

    An overview of the ATLAS liquid-argon calorimeter system is provided, along with a discussion of its operation and performance during the first year of LHC running. Upgrade planning related to the proposed high-luminosity upgrade of the LHC is also discussed, with an emphasis on the forward part of the calorimeter where the effects of the higher luminosity are a particular challenge. (authors)

  10. Development of MQXF: The Nb3Sn low-β quadrupole for the HiLumi LHC

    SciTech Connect

    Ferracin, P.; G. Ambrosio; Anerella, M.; Ballarino, A.; Bajas, H.; Bajko, M.; Bordini, B.; Bossert, R.; Cheng, D. W.; Dietderich, D. R.; Chlachidze, G.; Cooley, L.; Felice, H.; Ghosh, A.; Hafalia, R.; Holik, E.; Bermudez, S. Izquierdo; Fessia, P.; Grosclaude, P.; Guinchard, M.; Juchno, M.; Krave, S.; Lackner, F.; Marchevsky, M.; Marinozzi, V.; Nobrega, F.; Oberli, L.; Pan, H.; Perez, J. C.; Prin, H.; Rysti, J.; Rochepault, E.; Sabbi, G.; Salmi, T.; Schmalzle, J.; Sorbi, M.; Tavares, S. Sequeira; Todesco, E.; Wanderer, P.; Wang, X.; Yu, M.

    2015-12-18

    The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating at magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Europeen pour la Recherche Nucleaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. Lastly, this paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.

  11. 2016 SPD: Day 1

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    Editors note: This week were in Boulder, Colorado at the 47th meeting of the AAS Solar Physics Division (SPD). Follow along to catch some of the latest news from the field of solar physics!The 2016 SPD meeting was launched this morning from the University of Colorado Boulder campus. Two of the hot topics at this years meeting include celebration of the recent move of the National Solar Observatorys headquarters to Boulder, and discussion of the future Daniel K. Inouye Solar Telescope (DKIST, formerly the Advanced Technology Solar Telescope, ATST). DKIST, planned for a 2019 completion in Hawaii, is the next big telescope on the horizon for solar physics.Todays press conference had an interesting focus: instruments providing new high-energy observations of the Sun. Representatives from four different instruments were here to talk about some of the latest X-ray solar observations.GRIPSThe GRIPS payload flew at 130,000 ft over Antarctica on a giant balloon in January 2016. [NASA/Albert Shih]First up, Albert Shih (NASA Goddard) described the Gamma-Ray Imager/Polarimeter for Solar flares, or GRIPS. GRIPS is a balloon-borne instrument designed to detect X-rays and gamma rays emitted during solar flares. Up to tens of a percent of the energy in solar flares is emitted in the form of accelerated particles, but the physics behind this process is not well understood. GRIPS observes where the highest-energy particles are accelerated, in an effort to learn more about the process.GRIPS was launched on 19 January, 2016 and flew for roughly 12 days gathering ~1 million seconds of data! The logistics of this instruments flight are especially interesting, since it was launched from Antarctica and carried by a balloon at a whopping elevation of 130,000 ft (to get high enough that the atmosphere doesnt absorb all the photons GRIPS is trying to observe). Though the data from the mission has been retrieved, the bulk of the hardware remains where it landed at the end of January. It must

  12. Family Day Care Training Curriculum.

    ERIC Educational Resources Information Center

    Nakatsu, Gail

    California's Family Day Care Training Program was designed to recruit and train in 7 weeks, Lao, Vietnamese, and Chinese refugees to establish their own state-licensed, family day care homes. Topics in the program's curriculum include an introduction to family day care, state licenses for family day care, state licensing requirements for family…

  13. 2016 SPD: Day 1

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    Editors note: This week were in Boulder, Colorado at the 47th meeting of the AAS Solar Physics Division (SPD). Follow along to catch some of the latest news from the field of solar physics!The 2016 SPD meeting was launched this morning from the University of Colorado Boulder campus. Two of the hot topics at this years meeting include celebration of the recent move of the National Solar Observatorys headquarters to Boulder, and discussion of the future Daniel K. Inouye Solar Telescope (DKIST, formerly the Advanced Technology Solar Telescope, ATST). DKIST, planned for a 2019 completion in Hawaii, is the next big telescope on the horizon for solar physics.Todays press conference had an interesting focus: instruments providing new high-energy observations of the Sun. Representatives from four different instruments were here to talk about some of the latest X-ray solar observations.GRIPSThe GRIPS payload flew at 130,000 ft over Antarctica on a giant balloon in January 2016. [NASA/Albert Shih]First up, Albert Shih (NASA Goddard) described the Gamma-Ray Imager/Polarimeter for Solar flares, or GRIPS. GRIPS is a balloon-borne instrument designed to detect X-rays and gamma rays emitted during solar flares. Up to tens of a percent of the energy in solar flares is emitted in the form of accelerated particles, but the physics behind this process is not well understood. GRIPS observes where the highest-energy particles are accelerated, in an effort to learn more about the process.GRIPS was launched on 19 January, 2016 and flew for roughly 12 days gathering ~1 million seconds of data! The logistics of this instruments flight are especially interesting, since it was launched from Antarctica and carried by a balloon at a whopping elevation of 130,000 ft (to get high enough that the atmosphere doesnt absorb all the photons GRIPS is trying to observe). Though the data from the mission has been retrieved, the bulk of the hardware remains where it landed at the end of January. It must

  14. AAS 227: Day 1

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Editors Note:This week were at the 227th AAS Meeting in Kissimmee, FL. Along with several fellow authors from astrobites.com, I will bewritingupdates on selectedevents at themeeting and posting at the end of each day. Follow along here or at astrobites.com, or catch ourlive-tweeted updates from the @astrobites Twitter account. The usual posting schedule for AAS Nova will resumenext week.Things kicked off last night at our undergraduate reception booth. Thanks to all of you who stopped by we were delightedto have so many people tell us that they already know about and useastrobites, and we were excited to introduce a new cohort of students at AAS to astrobites for the first time.Tuesday morning was the official start of the meeting. Here are just a few of the talks and workshops astrobiters attended today.Opening Address (by Becky Smethurst)The President of the AAS, aka our fearless leader Meg Urry kicked off the meeting this morning at the purely coffee powered hour of 8am this morning. She spoke about the importance of young astronomers at the meeting (heres looking at you reader!) and also the importance of the new Working Group for Accessibility and Disabilities (aka WGAD pronounced like wicked) at the AAS. The Society has made extra effort this year to make the conference accessible to all,a message which was very well received by everyone in attendance.Kavli Lecture: New Horizons Alan Stern (by Becky Smethurst)We were definitely spoilt with the first Plenary lecture at this years conference Alan Stern gave us a a review of the New Horizons mission of the Pluto Fly By (astrobites covered the mission back in July with this post). We were treated to beautiful images, wonderful results and a foray into geology.Before (Hubble) and after #NewHorizons. #thatisall #science #astro alanstern #aas227 pic.twitter.com/kkMt6RsSIR Science News (@topsciencething) January 5, 2016Some awesome facts from the lecture that blew my mind:New Horizons is now 2AU (!) beyond Pluto

  15. Using widgets to monitor the LHC experiments

    NASA Astrophysics Data System (ADS)

    González Caballero, I.; Sarkar, S.

    2011-12-01

    The complexity of the LHC experiments requires monitoring systems to verify the correct functioning of different sub-systems and to allow operators to quickly spot problems and issues that may cause loss of information and data. Due to the distributed nature of the collaborations and the different technologies involved, the information data that need to be correlated is usually spread over several databases, web pages and monitoring systems. On the other hand, although the complete set of monitorable aspects is known and fixed, the subset that each person needs to monitor is often different for each individual. Therefore, building a unique monitoring tool that suits every single collaborator becomes close to impossible. A modular approach with a set of customizable widgets, small autonomous portions of HTML and JavaScript, that can be aggregated to form private or public monitoring web pages can be a scalable and robust solution, where the information can be provided by a simple and thin set of web services. Among the different widget development toolkits available today, we have chosen the open project UWA (Unified Widget API) because of its portability to the most popular widget platforms (including iGoogle, Netvibes and Apple Dashboard). As an example, we show how this technology is currently being used to monitor parts of the CMS Computing project.

  16. The LHCf experiment at the LHC accelerator

    SciTech Connect

    Bonechi, L.; Adriani, O.; Bongi, M.; D'Alessandro, R.; Papini, P.; Castellini, G.; Faus, A.; Velasco, J.; Haguenauer, M.; Itow, Y.; Mase, T.; Masuda, K.; Matsubara, Y.; Matsumoto, H.; Menjo, H.; Muraki, Y.; Sako, T.; Tanaka, K.; Watanabe, H.; Kasahara, K.

    2006-10-27

    The claimed discovery of atmospheric shower induced by cosmic-ray with energy beyond the GZK cutoff by the AGASA experiment in 1994-1995, although not confirmed by other important experiments like Fly's Eye and Hi-Res, together with the poor knowledge of the composition of cosmic rays around and beyond the Knee region, have highlighted the necessity of new experiments that should increase our present knowledge of HECR and UHECR. For this reason big efforts have been addressed to the development of new experiments, like Auger, TA and EUSO, for a systematic study of the UHE atmospheric showers with increased capabilities with respect to the previous experiments. Moreover complementary experiments should allow a precise calibration of the methods used for the reconstruction of cosmic-ray showers in atmosphere. Their aim is the measurement of quantities that are used in these procedures and that are not yet precisely known. Under this perspective the LHCf experiment is a compact experiment which has been proposed for the study of neutral pion and gamma production at high energy in proton-proton interaction in the very forward region of the LHC accelerator. It will help calibrating the algorithms that are used to reconstruct the atmospheric shower events for energy beyond the Knee. The LHCf apparatus and the results of the first beam test, held in 2004, are shortly discussed in this work.

  17. QCD, Tevatron results and LHC prospects

    SciTech Connect

    Elvira, V.Daniel; /Fermilab

    2008-08-01

    We present a summary of the most recent measurements relevant to Quantum Chromodynamics (QCD) delivered by the D0 and CDF Tevatron experiments by May 2008. CDF and D0 are moving toward precision measurements of QCD based on data samples in excess of 1 fb-1. The inclusive jet cross sections have been extended to forward rapidity regions and measured with unprecedented precision following improvements in the jet energy calibration. Results on dijet mass distributions, bbbar dijet production using tracker based triggers, underlying event in dijet and Drell-Yan samples, inclusive photon and diphoton cross sections complete the list of measurements included in this paper. Good agreement with pQCD within errors is observed for jet production measurements. An improved and consistent theoretical description is needed for photon+jets processes. Collisions at the LHC are scheduled for early fall 2008, opening an era of discoveries at the new energy frontier, 5-7 times higher than that of the Tevatron.

  18. Precision diboson observables for the LHC

    NASA Astrophysics Data System (ADS)

    Frye, Christopher; Freytsis, Marat; Scholtz, Jakub; Strassler, Matthew J.

    2016-03-01

    Motivated by the restoration of SU(2) × U(1) at high energy, we suggest that certain ratios of diboson differential cross sections can be used as high-precision observables at the LHC. We rewrite leading-order diboson partonic cross sections in a form that makes their SU(2) × U(1) and custodial SU(2) structure more explicit than in previous literature, and identify important aspects of this structure that survive even in hadronic cross sections. We then focus on higher-order corrections to ratios of γγ, Zγ and ZZ processes, including full next-to-leading-order corrections and gg initial-state contributions, and argue that these ratios can likely be predicted to better than 5%, which should make them useful in searches for new phenomena. The ratio of Zγ to γγ is especially promising in the near term, due to large rates and to exceptional cancellations of QCD-related uncertainties. We argue that electroweak corrections are moderate in size, have small uncertainties, and can potentially be observed in these ratios in the long run.

  19. Specialized minimal PDFs for optimized LHC calculations

    NASA Astrophysics Data System (ADS)

    Carrazza, Stefano; Forte, Stefano; Kassabov, Zahari; Rojo, Juan

    2016-04-01

    We present a methodology for the construction of parton distribution functions (PDFs) designed to provide an accurate representation of PDF uncertainties for specific processes or classes of processes with a minimal number of PDF error sets: specialized minimal PDF sets, or SM-PDFs. We construct these SM-PDFs in such a way that sets corresponding to different input processes can be combined without losing information, specifically as regards their correlations, and that they are robust upon smooth variations of the kinematic cuts. The proposed strategy never discards information, so that the SM-PDF sets can be enlarged by the addition of new processes, until the prior PDF set is eventually recovered for a large enough set of processes. We illustrate the method by producing SM-PDFs tailored to Higgs, top-quark pair, and electroweak gauge boson physics, and we determine that, when the PDF4LHC15 combined set is used as the prior, around 11, 4, and 11 Hessian eigenvectors, respectively, are enough to fully describe the corresponding processes.

  20. Symmetry restored in dibosons at the LHC?

    SciTech Connect

    Brehmer, Johann; Hewett, JoAnne; Kopp, Joachim; Rizzo, Thomas; Tattersall, Jamie

    2015-10-28

    A number of LHC resonance search channels display an excess in the invariant mass region of 1.8–2.0 TeV. Among them is a 3.4σ excess in the fully hadronic decay of a pair of Standard Model electroweak gauge bosons, in addition to potential signals in the HW and dijet final states. We perform a model-independent cross-section fit to the results of all ATLAS and CMS searches sensitive to these final states. We then interpret these results in the context of the Left-Right Symmetric Model, based on the extended gauge group SU(2)L × SU(2)R × U(1)', and show that a heavy right-handed gauge boson WR can naturally explain the current measurements with just a single coupling gR ~ 0.4. Thus, we discuss a possible connection to dark matter.

  1. Physics opportunities at RHIC and LHC

    SciTech Connect

    Scherer, S.; Bass, S. A.; Bleicher, M.; Brachmann, J.; Dumitru, A.; Ernst, C.; Gerland, L.; Hammon, N.; Hofmann, M.; Konopka, J.; Neise, L.; Reiter, M.; Schramm, S.; Soff, S.; Spieles, C.; Weber, H.; Zschiesche, D.; Maruhn, J. A.; Stoecker, H.; Greiner, W.

    1999-07-02

    Nonequilibrium models (three-fluid hydrodynamics, UrQMD, and quark molecular dynamics) are used to discuss the uniqueness of often proposed experimental signatures for quark matter formation in relativistic heavy ion collisions from the SPS via RHIC to LHC. It is demonstrated that these models--although they do treat the most interesting early phase of the collisions quite differently (thermalizing QGP vs. coherent color fields with virtual particles)--all yield a reasonable agreement with a large variety of the available heavy ion data. Hadron/hyperon yields, including J/{psi} meson production/suppression, strange matter formation, dileptons, and directed flow (bounce-off and squeeze-out) are investigated. Observations of interesting phenomena in dense matter are reported. However, we emphasize the need for systematic future measurements to search for simultaneous irregularities in the excitation functions of several observables in order to come close to pinning the properties of hot, dense QCD matter from data. The role of future experiments with the STAR and ALICE detectors is pointed out.

  2. Fastlim: a fast LHC limit calculator

    NASA Astrophysics Data System (ADS)

    Papucci, Michele; Sakurai, Kazuki; Weiler, Andreas; Zeune, Lisa

    2014-11-01

    Fastlim is a tool to calculate conservative limits on extensions of the Standard Model from direct LHC searches without performing any Monte Carlo event generation. The program reconstructs the visible cross sections (cross sections after event selection cuts) from pre-calculated efficiency tables and cross section tables for simplified event topologies. As a proof of concept of the approach, we have implemented searches relevant for supersymmetric models with R-parity conservation. Fastlim takes the spectrum and coupling information of a given model point and provides, for each signal region of the implemented analyses, the visible cross sections normalised to the corresponding upper limit, reported by the experiments, as well as the value. To demonstrate the utility of the program we study the sensitivity of the recent ATLAS missing energy searches to the parameter space of natural SUSY models. The program structure allows the straightforward inclusion of external efficiency tables and can be generalised to R-parity violating scenarios and non-SUSY models. This paper serves as a self-contained user guide and indicates the conventions and approximations used.

  3. 2016 SPD: Day 3

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    last the longest 2 minutes and 40 seconds is the small town of Hopkinsville, KY. WKU is located a little over an hour away, and both locations are prepared for a large influx of people on eclipse day!Partial solar eclipse as viewed by the space-based Solar Dynamics Observatory. [NASA/SDO]WKU is located just off the centerline of eclipse path, which has some advantages: this provides better viewing of some of the chromospheric features of the Sun during the eclipse, like priminences and solar loops. WKU is setting up a variety of educational and public outreach activities at their football stadium and the WKU farm, and they encourage you to come visit for the eclipse!In addition, they are participating in a nationwide experiment called Citizen CATE, short for the Continental American Telescopic Eclipse. This project will use 60 telescopes spanning the 2500 mile path of totality to record continuous data of the eclipse as it travels across the US. The result will be data of a remarkable 90 minutes of totality, revealing the activity of the solar corona and providing an extended view of the eclipse as has never been seen before.Science During the EclipseNext up was Shadia Habbal (University of Hawaii), who is a co-leader of the AAS 2017 Eclipse Task Force. In addition to her education and outreach efforts associated with the eclipse, however, Habbal is a solar eclipse researcher. She and her collaborators are known as the Solar Wind Sherpas, due to the fact that they hand-carry their science equipment around the world for solar eclipses!Solar corona during a 2008 eclipse, with color overlay indicating emission from highly ionized iron lines. [Habbal et al. 2010]The primary science done during solar eclipses is the study of the solar corona, the region that extends from the solar surface out to several solar radii. This region is too faint to observe normally, but when the light from the Suns disk is blocked out, we can examine it.Unfortunately, the space telescopes that

  4. AAS 228: Day 4

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    Editors Note: Lastweek we were at the 228th AAS Meeting in San Diego, CA. Here is a final post aboutselectedevents on the last day of the meeting, written by authors fromastrobites.com, a grad-student collaborative project with which we recently announced a new partnership! Starting in July,keep an eye out for astrobites postsat AAS Nova in between Highlights(i.e., on Tuesdays and Thursdays).Were excited to be working together to bring you more recent astronomy research from AAS journals!Extrasolar Planets: Detection (by Leonardo dos Santos)Thursdays first session on exoplanets was about detecting these distant worlds, and the opening talk was given by Robert Siverd (Las Cumbres Observatory). He describes the NRES, a network of spectrographs that will look for exoplanets using the radial velocity method. One of the coolest aspects of this instrument is that it will feature an on the fly scheduling system that will perform observations as efficiently as possible. The spectrograph is still being tested, but a unit will be deployed at CTIO later this year.@lcogt contracted by @NASA_TESS for follow up of their candidates. #aas228 Jessie Christiansen (@aussiastronomer) June 16, 2016Measuring the depths of transits and eclipses in Spitzer has been problematic in the past, since the Spitzer instrument IRAC (InfraRed Array Camera) has a non-uniform response in its detectors pixels. But, as reported by James Ingalls (Spitzer Science Center, Caltech), observers are circumventing this issue by using what they call the staring mode (avoiding large pointing jumps) and an algorithm to pick sweet spot pixels. Moreover, the results from the IRAC Data Challenge are helping to better understand its behavior. Giuseppe Morello (University College London), on the other hand, explained how his research group gets rid of instrumental effects from IRAC using machine learning. This method removes systematics from exoplanet transit data no matter if the noise source is from an instrument or

  5. Southeast Elevation, Attic Stair Nosing, Day Room Fireplace Details, Day ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Southeast Elevation, Attic Stair Nosing, Day Room Fireplace Details, Day Room Mantel Shelf, Northeast Elevation - National Home for Disabled Volunteer Soldiers - Battle Mountain Sanitarium, Ward 4, 500 North Fifth Street, Hot Springs, Fall River County, SD

  6. 2016 SPD: Day 3

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    last the longest 2 minutes and 40 seconds is the small town of Hopkinsville, KY. WKU is located a little over an hour away, and both locations are prepared for a large influx of people on eclipse day!Partial solar eclipse as viewed by the space-based Solar Dynamics Observatory. [NASA/SDO]WKU is located just off the centerline of eclipse path, which has some advantages: this provides better viewing of some of the chromospheric features of the Sun during the eclipse, like priminences and solar loops. WKU is setting up a variety of educational and public outreach activities at their football stadium and the WKU farm, and they encourage you to come visit for the eclipse!In addition, they are participating in a nationwide experiment called Citizen CATE, short for the Continental American Telescopic Eclipse. This project will use 60 telescopes spanning the 2500 mile path of totality to record continuous data of the eclipse as it travels across the US. The result will be data of a remarkable 90 minutes of totality, revealing the activity of the solar corona and providing an extended view of the eclipse as has never been seen before.Science During the EclipseNext up was Shadia Habbal (University of Hawaii), who is a co-leader of the AAS 2017 Eclipse Task Force. In addition to her education and outreach efforts associated with the eclipse, however, Habbal is a solar eclipse researcher. She and her collaborators are known as the Solar Wind Sherpas, due to the fact that they hand-carry their science equipment around the world for solar eclipses!Solar corona during a 2008 eclipse, with color overlay indicating emission from highly ionized iron lines. [Habbal et al. 2010]The primary science done during solar eclipses is the study of the solar corona, the region that extends from the solar surface out to several solar radii. This region is too faint to observe normally, but when the light from the Suns disk is blocked out, we can examine it.Unfortunately, the space telescopes that

  7. AAS 228: Day 4

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    Editors Note: Lastweek we were at the 228th AAS Meeting in San Diego, CA. Here is a final post aboutselectedevents on the last day of the meeting, written by authors fromastrobites.com, a grad-student collaborative project with which we recently announced a new partnership! Starting in July,keep an eye out for astrobites postsat AAS Nova in between Highlights(i.e., on Tuesdays and Thursdays).Were excited to be working together to bring you more recent astronomy research from AAS journals!Extrasolar Planets: Detection (by Leonardo dos Santos)Thursdays first session on exoplanets was about detecting these distant worlds, and the opening talk was given by Robert Siverd (Las Cumbres Observatory). He describes the NRES, a network of spectrographs that will look for exoplanets using the radial velocity method. One of the coolest aspects of this instrument is that it will feature an on the fly scheduling system that will perform observations as efficiently as possible. The spectrograph is still being tested, but a unit will be deployed at CTIO later this year.@lcogt contracted by @NASA_TESS for follow up of their candidates. #aas228 Jessie Christiansen (@aussiastronomer) June 16, 2016Measuring the depths of transits and eclipses in Spitzer has been problematic in the past, since the Spitzer instrument IRAC (InfraRed Array Camera) has a non-uniform response in its detectors pixels. But, as reported by James Ingalls (Spitzer Science Center, Caltech), observers are circumventing this issue by using what they call the staring mode (avoiding large pointing jumps) and an algorithm to pick sweet spot pixels. Moreover, the results from the IRAC Data Challenge are helping to better understand its behavior. Giuseppe Morello (University College London), on the other hand, explained how his research group gets rid of instrumental effects from IRAC using machine learning. This method removes systematics from exoplanet transit data no matter if the noise source is from an instrument or

  8. Developments on DC/DC converters for the LHC experiment upgrades

    NASA Astrophysics Data System (ADS)

    Abbate, C.; Alderighi, M.; Baccaro, S.; Busatto, G.; Citterio, M.; Cova, P.; Delmonte, N.; De Luca, V.; Fiore, S.; Gerardin, S.; Ghisolfi, E.; Giuliani, F.; Iannuzzo, F.; Lanza, A.; Latorre, S.; Lazzaroni, M.; Meneghesso, G.; Paccagnella, A.; Rampazzo, F.; Riva, M.; Sanseverino, A.; Silvestri, R.; Spiazzi, G.; Velardi, F.; Zanoni, E.

    2014-02-01

    Prototypes of DC/DC power and Point of Load (PoL) converters were designed and built with the aim of satisfying the foreseen working parameters of the High Luminosity (HL) LHC experiments, using both Silicon (Si) MOSFETs and/or more recent devices substantiated of better power performance, like Silicon Carbide (SiC) and Gallium Nitride (GaN) transistors. Optimization of their design, based on the comparison between the simulated and measured thermal, electrical and mechanical performance, is in progress, and many improvements with respect to the previous versions are under implementation. We discuss in this paper the results of the last modifications. In addition, many tens of discrete component samples, chosen among the devices commercially available in the three different technologies (Si, SiC and GaN), were electrically characterized and tested under γ-rays, neutron, proton and heavy ion radiation, also using a combined run method. We have also planned to test some commercial DC/DCs under the extreme conditions of radiation and magnetic field expected in the upgrades of the LHC experiments. Here we show the first results on few samples.

  9. Laboratory and testbeam results for thin and epitaxial planar sensors for HL-LHC

    NASA Astrophysics Data System (ADS)

    Bubna, M.; Bortoletto, D.; Bolla, G.; Shipsey, I.; Manfra, M. J.; Khan, K.; Arndt, K.; Hinton, N.; Godshalk, A.; Kumar, A.; Menasce, D.; Moroni, L.; Chramowicz, J.; Lei, C. M.; Prosser, A.; Rivera, R.; Uplegger, L.; Lo Vetere, M.; Robutti, E.; Ferro, F.; Ravera, F.; Costa, Marco

    2015-08-01

    The High-Luminosity LHC (HL-LHC) upgrade of the CMS pixel detector will require the development of novel pixel sensors which can withstand the increase in instantaneous luminosity to L=5×1034 cm-2s-1 and collect ~ 3000 fb-1 of data. The innermost layer of the pixel detector will be exposed to doses of about 1016 neq/ cm2. Hence, new pixel sensors with improved radiation hardness need to be investigated. A variety of silicon materials (Float-zone, Magnetic Czochralski and Epitaxially grown silicon), with thicknesses from 50 μm to 320 μm in p-type and n-type substrates have been fabricated using single-sided processing. The effect of reducing the sensor active thickness to improve radiation hardness by using various techniques (deep diffusion, wafer thinning, or growing epitaxial silicon on a handle wafer) has been studied. The results for electrical characterization, charge collection efficiency, and position resolution of various n-on-p pixel sensors with different substrates and different pixel geometries (different bias dot gaps and pixel implant sizes) will be presented.

  10. Tests of Radiation-Hard Silicon Microstrip Sensors for CMS in S-LHC

    SciTech Connect

    Luukka, Panja; Maenpaa, Teppo; Tuovinen, Esa; Spiegel, Lenny; Flight, Robert; /Rochester U.

    2011-02-21

    The tests are to study the performance of various silicon microstrip sensors that are sufficiently radiation-hard to be considered as candidates for the CMS outer (R > 25cm) tracker in the second phase of the currently envisioned S-LHC upgrade. The main goal of the beam test is to test Float Zone (FZ) and Magnetic Czochralski (MCz) silicon sensors that have been procured from Hamamatsu by the CMS collaboration as possible replacements for the CMS outer tracker for phase 2 operations. The detectors under test (DUT) will be isntalled in a cold box that contains 10 slots for modules based on CMS Tracker hybrids. Slots 1-4 and 7-10 are occupied by reference planes and slots 5 and 6 are reserved for DUTs. The box is cooled by Peltier elements in thermal contact with the top and bottom aluminum baseplates and is typically operated at around -25 C. A PCI based version of the CMS DAQ is used to read out the 10 slots based on triggers provided by beam scintillation counters. Given the low rate of beam particles the hybrid APVs will be operated in Peak mode, which maximizes the signal-to-noise performance of the readout chips. The internal clock operates at the LHC frequency of 40 MHz.

  11. Laboratory and testbeam results for thin and epitaxial planar sensors for HL-LHC

    DOE PAGESBeta

    Bubna, M.; Bolla, G.; Bortoletto, D.; Shipsey, I.; Manfra, M.; Khan, K.; Arndt, K.; Hinton, N.; Godshalk, A.; Kumar, A.; et al

    2015-08-03

    The High-Luminosity LHC (HL-LHC) upgrade of the CMS pixel detector will require the development of novel pixel sensors which can withstand the increase in instantaneous luminosity to L = 5 × 1034 cm–2s–1 and collect ~ 3000fb–1 of data. The innermost layer of the pixel detector will be exposed to doses of about 1016 neq/ cm2. Hence, new pixel sensors with improved radiation hardness need to be investigated. A variety of silicon materials (Float-zone, Magnetic Czochralski and Epitaxially grown silicon), with thicknesses from 50 μm to 320 μm in p-type and n-type substrates have been fabricated using single-sided processing. The effect ofmore » reducing the sensor active thickness to improve radiation hardness by using various techniques (deep diffusion, wafer thinning, or growing epitaxial silicon on a handle wafer) has been studied. Furthermore, the results for electrical characterization, charge collection efficiency, and position resolution of various n-on-p pixel sensors with different substrates and different pixel geometries (different bias dot gaps and pixel implant sizes) will be presented.« less

  12. Laboratory and testbeam results for thin and epitaxial planar sensors for HL-LHC

    SciTech Connect

    Bubna, M.; Bolla, G.; Bortoletto, D.; Shipsey, I.; Manfra, M.; Khan, K.; Arndt, K.; Hinton, N.; Godshalk, A.; Kumar, A.; Menasce, D.; Moroni, L.; Chramowicz, J.; Lei, C. M.; Prosser, A.; Rivera, R.; Uplegger, L.; Vetere, Maurizio Lo; Robutti, Enrico; Ferro, Fabrizio; Ravera, Fabio; Costa, Marco

    2015-08-03

    The High-Luminosity LHC (HL-LHC) upgrade of the CMS pixel detector will require the development of novel pixel sensors which can withstand the increase in instantaneous luminosity to L = 5 × 1034 cm–2s–1 and collect ~ 3000fb–1 of data. The innermost layer of the pixel detector will be exposed to doses of about 1016 neq/ cm2. Hence, new pixel sensors with improved radiation hardness need to be investigated. A variety of silicon materials (Float-zone, Magnetic Czochralski and Epitaxially grown silicon), with thicknesses from 50 μm to 320 μm in p-type and n-type substrates have been fabricated using single-sided processing. The effect of reducing the sensor active thickness to improve radiation hardness by using various techniques (deep diffusion, wafer thinning, or growing epitaxial silicon on a handle wafer) has been studied. Furthermore, the results for electrical characterization, charge collection efficiency, and position resolution of various n-on-p pixel sensors with different substrates and different pixel geometries (different bias dot gaps and pixel implant sizes) will be presented.

  13. The MoEDAL experiment - a new light on LHC physics

    NASA Astrophysics Data System (ADS)

    Pinfold, James L.

    2015-05-01

    In 2010 the MoEDAL experiment at the Large Hadron Collider (LHC) was unanimously approved by CERN's Research Board to start data taking in 2015. MoEDAL is a pioneering experiment designed to search for highly ionizing messengers of new physics such as magnetic monopoles or massive (pseudo-)stable charged particles. Its groundbreaking physics program defines a number of scenarios that yield potentially revolutionary insights into foundational questions. MoEDAL's purpose is to meet such far-reaching challenges at the frontier of the field. The innovative MoEDAL detector is tuned to the prospect of discovery physics. The largely passive MoEDAL detector, deployed at Point 8 on the LHC ring, has a dual nature. First, it acts like a giant camera, comprised of nuclear track detectors - analyzed offline by ultra fast scanning microscopes - sensitive only to new physics. Second, it is uniquely able to trap the particle harbingers of new physics beyond the Standard Model for further study. MoEDAL's radiation environment is monitored by a state-of-the-art real-time TimePix pixel detector array.

  14. AAS 227: Day 1

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Editors Note:This week were at the 227th AAS Meeting in Kissimmee, FL. Along with several fellow authors from astrobites.com, I will bewritingupdates on selectedevents at themeeting and posting at the end of each day. Follow along here or at astrobites.com, or catch ourlive-tweeted updates from the @astrobites Twitter account. The usual posting schedule for AAS Nova will resumenext week.Things kicked off last night at our undergraduate reception booth. Thanks to all of you who stopped by we were delightedto have so many people tell us that they already know about and useastrobites, and we were excited to introduce a new cohort of students at AAS to astrobites for the first time.Tuesday morning was the official start of the meeting. Here are just a few of the talks and workshops astrobiters attended today.Opening Address (by Becky Smethurst)The President of the AAS, aka our fearless leader Meg Urry kicked off the meeting this morning at the purely coffee powered hour of 8am this morning. She spoke about the importance of young astronomers at the meeting (heres looking at you reader!) and also the importance of the new Working Group for Accessibility and Disabilities (aka WGAD pronounced like wicked) at the AAS. The Society has made extra effort this year to make the conference accessible to all,a message which was very well received by everyone in attendance.Kavli Lecture: New Horizons Alan Stern (by Becky Smethurst)We were definitely spoilt with the first Plenary lecture at this years conference Alan Stern gave us a a review of the New Horizons mission of the Pluto Fly By (astrobites covered the mission back in July with this post). We were treated to beautiful images, wonderful results and a foray into geology.Before (Hubble) and after #NewHorizons. #thatisall #science #astro alanstern #aas227 pic.twitter.com/kkMt6RsSIR Science News (@topsciencething) January 5, 2016Some awesome facts from the lecture that blew my mind:New Horizons is now 2AU (!) beyond Pluto

  15. Design and Analysis of TQS01, a 90 mm Nb3Sn Model Quadrupole for LHC Luminosity Upgrade Based on a Key and Bladder Assembly

    SciTech Connect

    Caspi, S.; Ambrosio, G.; Andreev, N.; Barzi, E.; Bossert, R.C.; Dietderich, D.R.; Ferracin, P.; Ghosh, A.; Gourlay, S.A.; Hafalia, A.R.; Hannaford, C.R.; Kashikhin, V.S.; Kashikhin, V.V.; Lietzke, A.F.; Mattafirri, S.; McInturff, A.D.; Novitsky, I.V.; Sabbi, G.L.; Turrioni, D.; Yamada, R.; Zlobin, A.V.

    2006-06-01

    The US LHC Accelerator Research Program (LARP) is developing Nb{sub 3}Sn accelerator magnet technology for the LHC luminosity upgrade. Two 90 mm 'Technology Quadrupole' models (TQS01, TQC01) are being developed in close collaboration between LBNL and FNAL, using identical coil design, but two different support structures. The TQS01 structure was developed and tested at LBNL. With this approach coils are supported by an outer aluminum shell and assembled using keys and bladders. In contrast, the second model TQC01, utilize stainless steel collars and a thick stainless steel skin. This paper describes the TQS01 model magnet, its 3D ANSYS stress analysis, and anticipated instrumentation and assembly procedure.

  16. Field Quality Study of a 1-m-Long Single-Aperture 11-T Nb$_3$Sn Dipole Model for LHC Upgrades

    SciTech Connect

    Chlachidze, G.; DiMarco, J.; Andreev, N.; Apollinari, G.; Auchmann, B.; Barzi, E.; Bossert, R.; Fiscarelli, L.; Karppinen, M.; Nobrega, F.; Novitski, I.; Rossi, L.; Smekens, D.; Turrioni, D.; Velev, G. V.; Zlobin, A. V.

    2014-01-01

    FNAL and CERN are carrying out a joint R&D program with the goal of building a 5.5-m-long twin-aperture 11-T Nb_3Sn dipole prototype that is suitable for installation in the LHC. An important part of the program is the development and test of a series of short single-aperture and twin-aperture dipole models with a nominal field of 11 T at the LHC operation current of 11.85 kA and 20% margin. This paper presents the results of magnetic measurements of a 1-m-long single-aperture Nb_3Sn dipole model fabricated and tested recently at FNAL, including geometrical field harmonics and effects of coil magnetization and iron yoke saturation.

  17. Strong Coupling Gauge Theories in LHC ERA

    NASA Astrophysics Data System (ADS)

    Fukaya, H.; Harada, M.; Tanabashi, M.; Yamawaki, K.

    2011-01-01

    AdS/QCD, light-front holography, and the nonperturbative running coupling / Stanley J. Brodsky, Guy de Teramond and Alexandre Deur -- New results on non-abelian vortices - Further insights into monopole, vortex and confinement / K. Konishi -- Study on exotic hadrons at B-factories / Toru Iijima -- Cold compressed baryonic matter with hidden local symmetry and holography / Mannque Rho -- Aspects of baryons in holographic QCD / T. Sakai -- Nuclear force from string theory / K. Hashimoto -- Integrating out holographic QCD back to hidden local symmetry / Masayasu Harada, Shinya Matsuzaki and Koichi Yamawaki -- Holographic heavy quarks and the giant Polyakov loop / Gianluca Grignani, Joanna Karczmarek and Gordon W. Semenoff -- Effect of vector-axial-vector mixing to dilepton spectrum in hot and/or dense matter / Masayasu Harada and Chihiro Sasaki -- Infrared behavior of ghost and gluon propagators compatible with color confinement in Yang-Mills theory with the Gribov horizon / Kei-Ichi Kondo -- Chiral symmetry breaking on the lattice / Hidenori Fukaya [for JLQCD and TWQCD collaborations] -- Gauge-Higgs unification: Stable Higgs bosons as cold dark matter / Yutaka Hosotani -- The limits of custodial symmetry / R. Sekhar Chivukula ... [et al.] -- Higgs searches at the tevatron / Kazuhiro Yamamoto [for the CDF and D[symbol] collaborations] -- The top triangle moose / R. S. Chivukula ... [et al.] -- Conformal phase transition in QCD like theories and beyond / V. A. Miransky -- Gauge-Higgs unification at LHC / Nobuhito Maru and Nobuchika Okada -- W[symbol]W[symbol] scattering in Higgsless models: Identifying better effective theories / Alexander S. Belyaev ... [et al.] -- Holographic estimate of Muon g - 2 / Deog Ki Hong -- Gauge-Higgs dark matter / T. Yamashita -- Topological and curvature effects in a multi-fermion interaction model / T. Inagaki and M. Hayashi -- A model of soft mass generation / J. Hosek -- TeV physics and conformality / Thomas Appelquist -- Conformal

  18. Studies of RF Noise Induced Bunch Lengthening at the LHC

    SciTech Connect

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /SLAC /CERN

    2011-08-17

    Radio Frequency (RF) noise induced bunch lengthening can strongly affect the Large Hadron Collider (LHC) performance through luminosity reduction, particle loss, and other effects. This work presents measurements from the LHC that better quantify the relationship between the RF noise and longitudinal emittance blowup and identify the performance limiting RF components. The experiments presented in this paper confirmed the predicted effects on the LHC bunch length growth. Dedicated measurements were conducted in the LHC to gain insight in the effect of RF noise to the longitudinal beam diffusion. It was evident that the growth rate of the bunch length is strongly related to the accelerating voltage phase noise power spectral density around f{sub s} + kf{sub rev}, as predicted in [4]. The noise threshold for 2.5 ps/hr growth was estimated to -101 dBc/Hz (SSB flat noise spectral density from f{sub s} to the edge of the closed loop bandwidth). A 9 dB margin is achieved with the current RF configuration and the BPL on. With this formalism it is now possible to estimate the effect of different operational and technical RF configurations on the LHC beam diffusion. This formalism could also be useful for the design of future RF systems and the budgeting of the allowed noise.

  19. Stepping outside the neighborhood of T at LHC

    NASA Astrophysics Data System (ADS)

    Wiedemann, Urs Achim

    2009-11-01

    “ As you are well aware, many in the RHIC community are interested in the LHC heavy-ion program, but have several questions: What can we learn at the LHC that is qualitatively new? Are collisions at LHC similar to RHIC ones, just with a somewhat hotter/denser initial state? If not, why not? These questions are asked in good faith, and this talk is an opportunity to answer them directly to much of the RHIC community.” With these words, the organizers of Quark Matter 2009 in Knoxville invited me to discuss the physics opportunities for heavy ion collisions at the LHC without recalling the standard arguments, which are mainly based on the extended kinematic reach of the machine. In response, I emphasize here that lattice QCD indicates characteristic qualitative differences between thermal physics in the neighborhood of the critical temperature (T400-500MeV), for which the relevant energy densities will be solely attainable at the LHC.

  20. Supersymmetry Without Prejudice at the LHC

    SciTech Connect

    Conley, John A.; Gainer, James S.; Hewett, JoAnne L.; Le, My Phuong; Rizzo, Thomas G.; /SLAC

    2011-08-19

    The discovery and exploration of Supersymmetry in a model-independent fashion will be a daunting task due to the large number of soft-breaking parameters in the MSSM. In this paper, we explore the capability of the ATLAS detector at the LHC ({radical}s = 14 TeV, 1 fb{sup -1}) to find SUSY within the 19-dimensional pMSSM subspace of the MSSM using their standard transverse missing energy and long-lived particle searches that were essentially designed for mSUGRA. To this end, we employ a set of {approx} 71k previously generated model points in the 19-dimensional parameter space that satisfy all of the existing experimental and theoretical constraints. Employing ATLAS-generated SM backgrounds and following their approach in each of 11 missing energy analyses as closely as possible, we explore all of these 71k model points for a possible SUSY signal. To test our analysis procedure, we first verify that we faithfully reproduce the published ATLAS results for the signal distributions for their benchmark mSUGRA model points. We then show that, requiring all sparticle masses to lie below 1(3) TeV, almost all(two-thirds) of the pMSSM model points are discovered with a significance S > 5 in at least one of these 11 analyses assuming a 50% systematic error on the SM background. If this systematic error can be reduced to only 20% then this parameter space coverage is increased. These results are indicative that the ATLAS SUSY search strategy is robust under a broad class of Supersymmetric models. We then explore in detail the properties of the kinematically accessible model points which remain unobservable by these search analyses in order to ascertain problematic cases which may arise in general SUSY searches.

  1. Search for mirror quarks at the LHC

    NASA Astrophysics Data System (ADS)

    Chakdar, Shreyashi; Ghosh, K.; Hoang, V.; Hung, P. Q.; Nandi, S.

    2016-02-01

    Observation of nonzero neutrino masses at a scale ˜1 0-1- 1 0-2 eV is a major problem in the otherwise highly successful Standard Model. The most elegant mechanism to explain such tiny neutrino masses is the seesaw mechanism with right-handed neutrinos. However, the required seesaw scale is so high, ˜1014 GeV , it will not have any collider implications. Recently, an explicit model has been constructed to realize the seesaw mechanism with the right-handed neutrinos at the electroweak scale. The model has a mirror symmetry, having both the left and right lepton and quark doublets and singlets for the same S U (2 )W gauge symmetry. Additional Higgs multiplets have been introduced to realize this scenario. It turns out that these extra Higgs fields also help to satisfy the precision electroweak tests, and other observables. Because the scale of the symmetry breaking is electroweak, both the mirror quark and the mirror leptons have masses in the electroweak scale in the range ˜150 - 800 GeV . The mirror quarks/leptons decay to ordinary quarks/leptons plus very light neutral scalars. In this work, we calculate the final-state signals arising from the pair productions of these mirror quarks and their subsequent decays. We find that these signals are well observable over the Standard Model background for the 13 TeV LHC. Depending on the associated Yukawa couplings, these decays can also give rise to displaced vertices with long decay lengths, very different from the usual displaced vertices associated with b decays.

  2. Supersymmetry, Naturalness, and Signatures at the LHC

    SciTech Connect

    Kitano, Ryuichiro; Nomura, Yasunori

    2006-02-21

    Weak scale supersymmetry is often said to be fine-tuned, especially if the matter content is minimal. This is not true if there is a large {Alpha} term for the top squarks. We present a systematic study on fine-tuning in minimal supersymmetric theories and identify low energy spectra that do not lead to severe .ne-tuning. Characteristic features of these spectra are: a large {Alpha} term for the top squarks, small top squark masses, moderately large tan {beta}, and a small {mu} parameter. There are classes of theories leading to these features, which are discussed. In one class, which allows a complete elimination of fine-tuning, the Higgsinos are the lightest among all the superpartners of the standard model particles, leading to three nearly degenerate neutralino/chargino states. This gives interesting signals at the LHC--the dilepton invariant mass distribution has a very small endpoint and shows a particular shape determined by the Higgsino nature of the two lightest neutralinos. We demonstrate that these signals are indeed useful in realistic analyses by performing Monte Carlo simulations, including detector simulations and background estimations. We also present a method that allows the determination of all the relevant superparticle masses without using input from particular models, despite the limited kinematical information due to short cascades. This allows us to test various possible models, which is demonstrated in the case of a model with mixed moduli-anomaly mediation. We also give a simple derivation of special renormalization group properties associated with moduli mediated supersymmetry breaking, which are relevant in a model without fine-tuning.

  3. Last Days of Life (PDQ)

    MedlinePlus

    ... for more information. Symptoms During the Final Months, Weeks, and Days of Life Key Points Delirium Delirium ... may get worse during the final days or weeks of life. Shortness of breath or not being ...

  4. Assembly Tests of the First Nb 3 Sn Low-Beta Quadrupole Short Model for the Hi-Lumi LHC

    DOE PAGESBeta

    Pan, H.; Felice, H.; Cheng, D. W.; Anderssen, E.; Ambrosio, G.; Perez, J. C.; Juchno, M.; Ferracin, P.; Prestemon, S. O.

    2016-01-18

    In preparation for the high-luminosity upgrade of the Large Hadron Collider (LHC), the LHC Accelerator Research Program (LARP) in collaboration with CERN is pursuing the development of MQXF: a 150-mm-aperture high-field Nb3Sn quadrupole magnet. Moreover, the development phase starts with the fabrication and test of several short models (1.2-m magnetic length) and will continue with the development of several long prototypes. All of them are mechanically supported using a shell-based support structure, which has been extensively demonstrated on several R&D models within LARP. The first short model MQXFS-AT has been assembled at LBNL with coils fabricated by LARP and CERN.more » In our paper, we summarize the assembly process and show how it relies strongly on experience acquired during the LARP 120-mm-aperture HQ magnet series. We also present comparison between strain gauges data and finite-element model analysis. Finally, we present the implication of the MQXFS-AT experience on the design of the long prototype support structure.« less

  5. Lambda Front Propagation in the Superfluid Helium Contained in the External Auxiliary Bus-Bar Line of the LHC

    NASA Astrophysics Data System (ADS)

    Capatina, O.; Poncet, A.; Skoczen, B.

    2004-06-01

    The array of the corrector magnets of the LHC arc, associated with the main and some dispersion suppressor quadrupoles are powered by a special line routed inside the cryostat, running alongside the cold mass of the half-cell. This line, composed of a 50 mm diameter stainless steel tube fixed to the cold mass, houses the superconducting multi-wire cable(s) carrying the 600 A and 6 kA current to the corrector magnets and special quadrupoles. It is cooled down to 1.9 K with pressurized superfluid helium provided by links to the cold-mass placed at regular intervals (one half-cell). The paper is focused on the process of sub-cooling the long channel from 4.5 K down to 1.9 K, including the propagation of the lambda front along the pipeline. The mechanism of sub-cooling is based on a zone of phase transformation traveling along the channel, with the heat transport both in helium and in the copper wires. A new 2-D model, including the radial heat exchange between copper and He II, has been used to study the process. A clamped temperature problem with a jump-like variable section of the channel has been solved. The model has been applied to the analysis of recovery of the line after a quench in the main magnets. A comparison with the measurements in the LHC prototype cell (String 2) is shown.

  6. 2010 Stennis Day of Service

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Rich Delgado, commanding officer of the Fleet Survey Team located at NASA's John C. Stennis Space Center, visits with Kertrina Watson Lewis, executive director of the HandsOn volunteer organization in New Orleans, during Day of Service activities Jan. 12. The Day of Service was part of the annual Martin Luther King Jr. Day observance at Stennis. During the day, Mississippi and Louisiana organizations visited the center to encourage employees to register and serve as volunteers for various community activities.

  7. 2010 Stennis Day of Service

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Employees at NASA's John C. Stennis Space Center visit exhibits of volunteer organizations during their observance of Martin Luther King Jr. Day with a Day of Service on Jan. 12. During the day, Mississippi and Louisiana organizations visited the center to encourage employees to register and serve as volunteers for various community activities. The day's focus was emphasized again and again - great things can happen when individuals work together toward a common goal.

  8. Myth or Truth: Independence Day.

    ERIC Educational Resources Information Center

    Gardner, Traci

    Most Americans think of the Fourth of July as Independence Day, but is it really the day the U.S. declared and celebrated independence? By exploring myths and truths surrounding Independence Day, this lesson asks students to think critically about commonly believed stories regarding the beginning of the Revolutionary War and the Independence Day…

  9. The 4 Day School Week

    ERIC Educational Resources Information Center

    Dam, Ai

    2006-01-01

    Colorado law requires school districts to schedule 1080 hours per year of instructional time for secondary schools and 990 instructional hours for elementary schools. The 1080 hours equate to six hours per day for 180 days. The 990 hours equate to five and one-half hours per day. Up to 24 hours may be counted for parent-teacher conferences, staff…

  10. Perspectives on Infant Day Care.

    ERIC Educational Resources Information Center

    Elardo, Richard, E.; Pagan, Betty, Ed.

    These proceedings of the first annual SACUS workshop on infant day care contain the papers presented at the conference, plus an appendix--Developmental Objectives for Infants and Toddlers. The papers are: "Infant Day Care--Fads, Facts, and Fancies" by Bettye M. Caldwell; "Family Day Care""A Broad Perspective" by Malcolm S. Host; "Getting…

  11. National Trails Day. Project SEED.

    ERIC Educational Resources Information Center

    Simpson, Mark

    This paper describes how a school district in Maine implemented an outdoor education program centered around National Trails Day (a day of awareness of outdoor recreational areas in the United States). The program combined classroom learning with an all-day hike on the Appalachian Trail by 240 seventh-grade students. Numerous teachers, school…

  12. Family Day Care Provider Handbook

    ERIC Educational Resources Information Center

    New York State Office of Children and Family Services, 2006

    2006-01-01

    Family day care providers are responsible for creating a high-quality program where children have opportunities to grow, learn and thrive. Part of providing high-quality child care includes complying with the family day care regulations from the New York State Office of Children and Family Services (OCFS). This Handbook will help day care…

  13. Warm Magnetic Field Measurements of LARP HQ Magnet

    SciTech Connect

    Caspi, S; Cheng, D; Deitderich, D; Felice, H; Ferracin, P; Hafalia, R; Joseph, J; Lizarazo, J; Martchevskii, M; Nash, C; Sabbi, G L; Vu, C; Schmalzle, J; Ambrosio, G; Bossert, R; Chlachidze, G; DiMarco, J; Kashikhin, V

    2011-03-28

    The US-LHC Accelerator Research Program is developing and testing a high-gradient quadrupole (HQ) magnet, aiming at demonstrating the feasibility of Nb{sub 3}Sn technologies for the LHC luminosity upgrade. The 1 m long HQ magnet has a 120 mm bore with a conductor-limited gradient of 219 T/m at 1.9 K and a peak field of 15 T. HQ includes accelerator features such as alignment and field quality. Here we present the magnetic measurement results obtained at LBNL with a constant current of 30 A. A 100 mm long circuit-board rotating coil developed by FNAL was used and the induced voltage and flux increment were acquired. The measured b{sub 6} ranges from 0.3 to 0.5 units in the magnet straight section at a reference radius of 21.55 mm. The data reduced from the numerical integration of the raw voltage agree with those from the fast digital integrators.

  14. Summary of the Mini BNL/LARP/CARE-HHH Workshop on Crab Cavities for the LHC (LHC-CC08)

    SciTech Connect

    Ben-Zvi,I.; Calaga, R.; Zimmermann, F.

    2008-05-01

    The first mini-workshop on crab compensation for the LHC luminosity upgrade (LHC-CC08) was held February 24-25, 2008 at the Brookhaven National Laboratory. A total of 35 participants from 3 continents and 15 institutions from around the world participated to discuss the exciting prospect of a crab scheme for the LHC. If realized it will be the first demonstration in hadron colliders. The workshop is organized by joint collaboration of BNL, US-LARP and CARE-HHH. The enormous interest in the subject of crab cavities for the international linear collider and future light sources has resulted in a large international collaboration to exchange aspects of synergy and expertise. A central repository for this exchange of information documenting the latest design effort for LHC crab cavities is consolidated in a wiki page: https://twiki.cern.ch/twiki/bin/view/Main/LHCCrabCavities. The main goal of this workshop was to define a road-map for a prototype crab cavity to be installed in the LHC and to discuss the associated R&D and beam dynamics challenges. The diverse subject of implementing the crab scheme resulted in a scientific program with a wide range of subtopics which were divided into 8 sessions. Each session was given a list of fundamental questions to be addressed and used as a guideline to steer the discussions.

  15. All in a Day's Work

    ERIC Educational Resources Information Center

    Pierpont, Katherine

    2006-01-01

    This article is the story of Drummond Montessori Magnet School. From the sidewalk, Drummond Montessori Magnet School, a 117-year-old hulking mass of a building in Chicago, Illinois, appeared to be just another prosaic part of any American cityscape. This past May, the author witnessed a schoolyard scene that has probably unfolded numerous times in…

  16. The pMSSM Interpretation of LHC Results Using Rernormalization Group Invariants

    SciTech Connect

    Carena, Marcela; Lykken, Joseph; Sekmen, Sezen; Shah, Nausheen R.; Wagner, Carlos E.M.

    2012-10-01

    The LHC has started to constrain supersymmetry-breaking parameters by setting bounds on possible colored particles at the weak scale. Moreover, constraints from Higgs physics, flavor physics, the anomalous magnetic moment of the muon, as well as from searches at LEP and the Tevatron have set additional bounds on these parameters. Renormalization Group Invariants (RGIs) provide a very useful way of representing the allowed parameter space by making direct connection with the values of these parameters at the messenger scale. Using a general approach, based on the pMSSM parametrization of the soft supersymmetry-breaking parameters, we analyze the current experimental constraints to determine the probability distributions for the RGIs. As examples of their application, we use these distributions to analyze the question of Gaugino Mass Unification and to probabilistically determine the parameters of General and Minimal Gauge Mediation with arbitrary Higgs mass parameters at the Messenger Scale.

  17. LHC optics measurement with proton tracks detected by the Roman pots of the TOTEM experiment

    NASA Astrophysics Data System (ADS)

    The TOTEM Collaboration; Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Baechler, J.; Berardi, V.; Berretti, M.; Bossini, E.; Bottigli, U.; Bozzo, M.; Brücken, E.; Buzzo, A.; Cafagna, F. S.; Catanesi, M. G.; Covault, C.; Csanád, M.; Csörgö, T.; Deile, M.; Doubek, M.; Eggert, K.; Eremin, V.; Ferro, F.; Fiergolski, A.; Garcia, F.; Georgiev, V.; Giani, S.; Grzanka, L.; Hammerbauer, J.; Heino, J.; Hilden, T.; Karev, A.; Kašpar, J.; Kopal, J.; Kundrát, V.; Lami, S.; Latino, G.; Lauhakangas, R.; Leszko, T.; Lippmaa, E.; Lippmaa, J.; Lokajíček, M. V.; Losurdo, L.; Lo Vetere, M.; Rodríguez, F. Lucas; Macrí, M.; Mäki, T.; Mercadante, A.; Minafra, N.; Minutoli, S.; Nemes, F.; Niewiadomski, H.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Österberg, K.; Palazzi, P.; Peroutka, Z.; Procházka, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Saarikko, H.; Scribano, A.; Smajek, J.; Snoeys, W.; Sziklai, J.; Taylor, C.; Turini, N.; Vacek, V.; Welti, J.; Whitmore, J.; Wyszkowski, P.; Zielinski, K.

    2014-10-01

    Precise knowledge of the beam optics at the LHC is crucial to fulfill the physics goals of the TOTEM experiment, where the kinematics of the scattered protons is reconstructed with near-beam telescopes—so-called Roman pots (RP). Before being detected, the protons’ trajectories are influenced by the magnetic fields of the accelerator lattice. Thus precise understanding of the proton transport is of key importance for the experiment. A novel method of optics evaluation is proposed which exploits kinematical distributions of elastically scattered protons observed in the RPs. Theoretical predictions, as well as Monte Carlo studies, show that the residual uncertainty of the optics estimation method is smaller than 2.5.

  18. Air liquide 1.8 K refrigeration units for CERN LHC project

    NASA Astrophysics Data System (ADS)

    Hilbert, Benoît; Gistau-Baguer, Guy M.; Caillaud, Aurélie

    2002-05-01

    The Large Hadron Collider (LHC) will be CERN's next research instrument for high energy physics. This 27 km long circular accelerator will make intensive use of superconducting magnets, operated below 2.0 K. It will thus require high capacity refrigeration below 2.0 K [1, 2]. Coupled to a refrigerator providing 18 kW equivalent at 4.5 K [3], these systems will be able to absorb a cryogenic power of 2.4 kW at 1.8 K in nominal conditions. Air Liquide has designed one Cold Compressor System (CCS) pre-series for CERN-preceding 3 more of them (among 8 in total located around the machine). These systems, making use of cryogenic centrifugal compressors in a series arrangement coupled to room temperature screw compressors, are presented. Key components characteristics will be given.

  19. SMALL ANGLE CRAB COMPENSATION FOR LHC IR UPGRADE

    SciTech Connect

    CALAGA,R.; DORDA, U.; OHMI, D.; OIDE, K.; TOMAS, R.; ZIMMERMANN, F.

    2007-06-25

    A small angle (< 1 mrad) crab scheme is an attractive option for the LHC luminosity upgrade to recover the geometric luminosity loss from the finite crossing angle [I]. The luminosity loss increases steeply to unacceptable levels as the IP beta function is reduced below its nominal value (see Fig. 1 in Ref. [2]). The crab compensation in the LHC can be accomplished using only two sets of deflecting RF cavities, placed in collision-free straight sections of the LHC to nullify the effective crossing angles at IPI & IP5. We also explore a 400 MHz superconducting cavity design and discuss the pertinent RF challenges. We present IR optics configurations with low-angle crab crossing, study the beam-beam performance and proton-beam emittance growth in the presence of crab compensation, lattice errors, and crab RF noise sources.

  20. Probing Bino-Wino coannihilation at the LHC

    NASA Astrophysics Data System (ADS)

    Nagata, Natsumi; Otono, Hidetoshi; Shirai, Satoshi

    2015-10-01

    We study bino-wino coannihilation scenario in the so-called spread or mini-split supersymmetry. We show that, in this model, a neutral wino has a macroscopic decay length in a wide range of parameter space. This characteristic feature could be observed as a displaced vertex plus missing transverse energy event at the LHC. In this paper, we study the current constraints and future prospects on the scenario based on the displaced vertex search performed by the ATLAS collaboration. It is found that a sizable parameter region can be probed at the 8 TeV LHC run. This search strategy will considerably extend its reach at the next stage of the LHC running, and thus play a crucial role to examine a possibility of bino dark matter in the mini-split type supersymmetric models.

  1. Mono-Higgs detection of dark matter at the LHC

    NASA Astrophysics Data System (ADS)

    Berlin, Asher; Lin, Tongyan; Wang, Lian-Tao

    2014-06-01

    Motivated by the recent discovery of the Higgs boson, we investigate the possibility that a missing energy plus Higgs final state is the dominant signal channel for dark matter at the LHC. We consider examples of higher-dimension operators where a Higgs and dark matter pair are produced through an off-shell Z or γ, finding potential sensitivity at the LHC to cutoff scales of around a few hundred GeV. We generalize this production mechanism to a simplified model by introducing a Z' as well as a second Higgs doublet, where the pseudoscalar couples to dark matter. Resonant production of the Z' which decays to a Higgs plus invisible particles gives rise to a potential mono-Higgs signal. This may be observable at the 14 TeV LHC at low tan β and when the Z' mass is roughly in the range 600 GeV to 1.3 TeV.

  2. Constraints on sneutrino dark matter from LHC Run 1

    NASA Astrophysics Data System (ADS)

    Arina, Chiara; Catalan, Maria Eugenia Cabrera; Kraml, Sabine; Kulkarni, Suchita; Laa, Ursula

    2015-05-01

    A mostly right-handed sneutrino as the lightest supersymmetric particle (LSP) is an interesting dark matter candidate, leading to LHC signatures which can be quite distinct from those of the conventional neutralino LSP. Using SModelS v1.0.1 for testing the model against the limits published by ATLAS and CMS in the context of so-called Simplified Model Spectra (SMS), we investigate to what extent the supersymmetry searches at Run 1 of the LHC constrain the sneutrino-LSP scenario. Moreover, we discuss the most relevant topologies for which no SMS results are provided by the experimental collaborations but which would allow to put more stringent constraints on sneutrino LSPs. These include, for instance, the mono-lepton signature which should be particularly interesting to consider at Run 2 of the LHC.

  3. New Tools for Forecasting Old Physics at the LHC

    ScienceCinema

    None

    2011-10-06

    For the LHC to uncover many types of new physics, the "old physics" produced by the Standard Model must be understood very well. For decades, the central theoretical tool for this job was the Feynman diagram expansion. However, Feynman diagrams are just too slow, even on fast computers, to allow adequate precision for complicated LHC events with many jets in the final state. Such events are already visible in the initial LHC data. Over the past few years, alternative methods to Feynman diagrams have come to fruition. These new "on-shell" methods are based on the old principles of unitarity and factorization. They can be much more efficient because they exploit the underlying simplicity of scattering amplitudes, and recycle lower-loop information. I will describe how and why these methods work, and present some of the recent state-of-the-art results that have been obtained with them.

  4. New Tools for Forecasting Old Physics at the LHC

    SciTech Connect

    2011-01-21

    For the LHC to uncover many types of new physics, the "old physics" produced by the Standard Model must be understood very well. For decades, the central theoretical tool for this job was the Feynman diagram expansion. However, Feynman diagrams are just too slow, even on fast computers, to allow adequate precision for complicated LHC events with many jets in the final state. Such events are already visible in the initial LHC data. Over the past few years, alternative methods to Feynman diagrams have come to fruition. These new "on-shell" methods are based on the old principles of unitarity and factorization. They can be much more efficient because they exploit the underlying simplicity of scattering amplitudes, and recycle lower-loop information. I will describe how and why these methods work, and present some of the recent state-of-the-art results that have been obtained with them.

  5. Tevatron-for-LHC Report of the QCD Working Group

    SciTech Connect

    Albrow, Michael G.; Begel, M.; Bourilkov, D.; Campanelli, M.; Chlebana, F.; De Roeck, A.; Dittmann, J.R.; Ellis, S.D.; Field, B.; Field, R.; Gallinaro, M.; /Fermilab /Rochester U. /Florida U. /Geneva U. /CERN /Baylor U. /Washington U., Seattle /Florida State U. /Rockefeller U. /Prague, Tech. U. /Michigan State U.

    2006-10-01

    The experiments at Run 2 of the Tevatron have each accumulated over 1 fb{sup -1} of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focused on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop.

  6. A High Field Magnet Design for A Future Hadron Collider

    SciTech Connect

    Gupta, R.; Chow, K.; Dietderich, D.; Gourlay, S.; Millos, G.; McInturff, A.; Scanlan, R.

    1998-09-01

    US high energy physics community is exploring the possibilities of building a Very Large Hadron Collider (VLHC) after the completion of LHC. This paper presents a high field magnet design option based on Nb{sub 3}Sn technology. A preliminary magnetic and mechanical design of a 14-16 T, 2-in-1 dipole based on the 'common coil design' approach is presented. The computer code ROXIE has been upgraded to perform the field quality optimization of magnets based on the racetrack coil geometry. A magnet R&D program to investigate the issues related to high field magnet designs is also outlined.

  7. Day-to-day changes in ionospheric electron content at low latitudes

    NASA Astrophysics Data System (ADS)

    Dabas, R. S.; Bhuyan, P. K.; Tyagi, T. R.; Bhardwaj, R. K.; Lal, J. B.

    1984-06-01

    For a number of years, the ionospheric electron content (IEC) over the Indian subcontinent has been determined on the basis of the Faraday rotation of satellite radio beacon transmissions. In these determinations, use was made of the orbiting satellites BE-B and BE-C, and, for a limited period, of the geostationary satellite ATS 6. A large variability in day-to-day values of IEC was reported, and it was tried to correlate this phenomenon with magnetic activity, solar flux, or the effect of neutral winds. Tyagi (1978) observed that the day-to-day changes in IEC occur in the form of single day abnormality, and alternate day abnormality. Long-term fluctuations were found with a periodicity of about 45 days. The present investigation is concerned with a more detailed study of the observed variations. An analysis is conducted of IEC data recorded during the low phase of the solar cycle, taking into account data from six low-latitude stations covering a latitude range from approximately 15.0 deg N to 30.0 deg N.

  8. Probing baryogenesis with displaced vertices at the LHC

    NASA Astrophysics Data System (ADS)

    Cui, Yanou; Shuve, Brian

    2015-02-01

    The generation of the asymmetric cosmic baryon abundance requires a departure from thermal equilibrium in the early universe. In a large class of baryogenesis models, the baryon asymmetry results from the out-of-equilibrium decay of a new, massive particle. We highlight that in the interesting scenario where this particle has a weak scale mass, this out-of-equilibrium condition requires a proper decay length larger than O(1) mm. Such new fields are within reach of the LHC, at which they can be pair produced leaving a distinctive, displaced-vertex signature. This scenario is realized in the recently proposed mechanism of baryogenesis where the baryon asymmetry is produced through the freeze-out and subsequent decay of a meta-stable weakly interacting massive particle ("WIMP baryogenesis"). In analogy to missing energy searches for WIMP dark matter, the LHC is an excellent probe of these new long-lived particles responsible for baryogenesis via the low-background displaced vertex channel. In our paper, we estimate the limits on simplified models inspired by WIMP baryogenesis from two of the most sensitive collider searches by CMS and ATLAS with 8 TeV LHC data. We also estimate the LHC reach at 13 TeV using current strategies, and demonstrate that up to a factor of 100 improvement in cross-section limits can be achieved by requiring two displaced vertices while lowering kinematic thresholds. For meta-stable WIMPs produced through electroweak interactions, the high luminosity LHC is sensitive to masses up to 2.5 TeV for lifetimes around 1 cm, while for singlets pair-produced through the off-shell-Higgs portal, the LHC is sensitive to production cross sections of O(10) ab for benchmark masses around 150 GeV. Our analysis and proposals also generally apply to displaced vertex signatures from other new physics such as hidden valley models, twin Higgs models and displaced supersymmetry.

  9. LHC Higgs signatures from extended electroweak gauge symmetry

    NASA Astrophysics Data System (ADS)

    Abe, Tomohiro; Chen, Ning; He, Hong-Jian

    2013-01-01

    We study LHC Higgs signatures from the extended electroweak gauge symmetry SU(2) ⊗ SU(2) ⊗ U(1). Under this gauge structure, we present an effective UV completion of the 3-site moose model with ideal fermion delocalization, which contains two neutral Higgs states ( h, H) plus three new gauge bosons ( W ' , Z '). We study the unitarity, and reveal that the exact E 2 cancellation in the longitudinal V L V L scattering amplitudes is achieved by the joint role of exchanging both spin-1 new gauge bosons W ' /Z ' and spin-0 Higgs bosons h/H. We identify the lighter Higgs state h with mass 125 GeV, and derive the unitarity bound on the mass of heavier Higgs boson H. The parameter space of this model is highly predictive. We study the production and decay signals of this 125 GeV Higgs boson h at the LHC. We demonstrate that the h Higgs boson can naturally have enhanced signals in the diphoton channel gg → h → γγ, while the event rates in the reactions gg → h → W W ∗ and gg → h → ZZ ∗ are generally suppressed relative to the SM expectation. Searching the h Higgs boson via the associated production and the vector boson fusions are also discussed for our model. We further analyze the LHC signals of the heavier Higgs boson H as a new physics discriminator from the SM. For wide mass-ranges of H, we derive constraints from the existing LHC searches, and study the discovery potential of H at the LHC (8 TeV) and LHC (14 TeV).

  10. Electro-thermal FEM simulations of the 13 kA LHC joints

    NASA Astrophysics Data System (ADS)

    Molnar, D.; Verweij, A. P.; Bielert, E. R.

    2013-01-01

    The interconnections between the superconducting main dipole and main quadrupole magnets are made of soldered joints of two superconducting Nb-Ti cables embedded in a copper busbar stabilizer. The primary cause of the September 2008 incident in the LHC was a defect in an interconnection between two dipole magnets. Analyses of the incident show that possibly more defects might be present in the 13 kA circuits, which can lead to unprotected resistive transitions. To avoid the reoccurrence of such an event, thorough experimental and numerical investigations have taken place to determine the safe operating conditions of the LHC. However to show measured curves is beyond the scope of this article. Furthermore, improvements in the design have been proposed in the form of additional parallel copper pieces, or shunts, which bridge the possible voids in the soldering and offer a bypass for the current in case of a quench. The purpose of this work is to support the design choices and to indicate the sensitivity to some of the free parameters in the design. Electro-thermal Finite Element Method (FEM) simulations are performed, making use of COMSOL Multiphysics. The use of FEM allows for a profound three-dimensional analysis and some interesting features of the shunted busbar can only be revealed this way. Especially current redistribution in the shunted area of the interconnect gives important insights in the problem. The results obtained using the model are very sensitive to the exact geometrical properties as well as to the material properties, which drive the Joule heating inside the interconnection. Differences as compared to a one-dimensional model, QP3, are presented. QP3 is also used for simulations of non-shunted busbar joints as well as shunted busbars. Furthermore, margins are given for the soldering process and the quality control of the shunted interconnections, since the contact area between the stabilizer pieces and the shunt is an important quality aspect

  11. First Results from Pb+Pb Collisions at the LHC

    NASA Astrophysics Data System (ADS)

    Müller, Berndt; Schukraft, Jürgen; Wysłouch, Bolesław

    2012-11-01

    At the end of 2010, the Large Hadron Collider (LHC) at CERN started operation with heavy-ion beams, colliding lead nuclei at a center-of-mass energy of 2.76 TeV per nucleon. These collisions ushered in a new era in ultrarelativistic heavy-ion physics at energies exceeding that of previous accelerators by more than an order of magnitude. This review summarizes the results from the first year of heavy-ion physics at the LHC obtained by the three experiments participating in the heavy-ion program: ALICE, ATLAS, and CMS.

  12. First Experiences with LHC Grid Computing and Distributed Analysis

    SciTech Connect

    Fisk, Ian

    2010-12-01

    In this presentation the experiences of the LHC experiments using grid computing were presented with a focus on experience with distributed analysis. After many years of development, preparation, exercises, and validation the LHC (Large Hadron Collider) experiments are in operations. The computing infrastructure has been heavily utilized in the first 6 months of data collection. The general experience of exploiting the grid infrastructure for organized processing and preparation is described, as well as the successes employing the infrastructure for distributed analysis. At the end the expected evolution and future plans are outlined.

  13. Multivariate Search of the Standard Model Higgs Boson at LHC

    SciTech Connect

    Mjahed, Mostafa

    2007-01-12

    resent an attempt to identify the SM Higgs boson at LHC in the channel (pp-bar {yields} HX {yields} W+ W-X {yields} l+ vl- v X). We use a multivariate processing of data as a tool for a better discrimination between signal and background (via Principal Components Analysis, Genetic Algorithms and Neural Network). Events were produced at LHC energies (MH = 140 - 200 GeV), using the Lund Monte Carlo generator PYTHIA 6.1. Higgs boson events (pp-bar {yields} HX {yields} W+W-X {yields} l+ vl- v X) and the most relevant background are considered.

  14. First LHC beam induced tracks reconstructed in the LHCb VELO

    NASA Astrophysics Data System (ADS)

    Parkes, C.; Borghi, S.; Bates, A.; Eklund, L.; Gersabeck, M.; Marinho, F.; Rakotomiaramanana, B.; Rodrigues, E.; Szumlak, T.; Affolder, A.; Bowcock, T.; Casse, G.; Donleavy, S.; Hennessy, K.; Huse, T.; Hutchcroft, D.; Mylroie-Smith, J.; Noor, A.; Patel, G.; Rinnert, K.; Smith, N. A.; Shears, T.; Tobin, M.; John, M.; Bay, A.; Frei, R.; Haefeli, G.; Keune, A.; Anderson, J.; McNulty, R.; Traynor, S.; Basiladze, S.; Leflat, A.; Artuso, M.; Borgia, A.; Lefeuvre, G.; Mountain, R.; Wang, J.; Akiba, K.; van Beuzekom, M.; Jans, E.; Ketel, T.; Mous, I.; Papadelis, A.; Van Lysebetten, A.; Verlaat, B.; de Vries, H.; Behrendt, O.; Buytaert, J.; de Capua, S.; Collins, P.; Ferro-Luzzi, M.

    2009-06-01

    The Vertex Locator of the LHCb experiment has been used to fully reconstruct beam induced tracks at the LHC. A beam of protons was collided with a beam absorber during the LHC synchronisation test of the anti-clockwise beam on the weekend 22nd-24th August 2008. The resulting particles have been observed by the Vertex Locator. The LHCb Vertex Locator is a silicon micro-strip detector containing 21 planes of modules. Tracks were observed passing through up to 19 modules (38 silicon sensors). A total of over 700 tracks were reconstructed, and are being used to study the calibration and alignment of the detector.

  15. Constraining portals with displaced Higgs decay searches at the LHC

    NASA Astrophysics Data System (ADS)

    Clarke, Jackson D.

    2015-10-01

    It is very easy to write down models in which long-lived particles decaying to standard model states are pair-produced via Higgs decays, resulting in the signature of approximately back-to-back pairs of displaced narrow hadronic jets and/or lepton jets at the LHC. The LHC collaborations have already searched for such signatures with no observed excess. This paper describes a Monte Carlo method to reinterpret the searches. The method relies on (ideally multidimensional) efficiency tables, thus we implore collaborations to include them in any future work. Exclusion regions in mixing-mass parameter space are presented which constrain portal models.

  16. Right-handed lepton mixings at the LHC

    NASA Astrophysics Data System (ADS)

    Vasquez, Juan Carlos

    2016-05-01

    We study how the elements of the leptonic right-handed mixing matrix can be determined at the LHC in the minimal Left-Right symmetric extension of the standard model. We do it by explicitly relating them with physical quantities of the Keung-Senjanović process and the lepton number violating decays of the right doubly charged scalar. We also point out that the left and right doubly charged scalars can be distinguished at the LHC, without measuring the polarization of the final state leptons coming from their decays.

  17. The gauge-Higgs legacy of the LHC Run I

    NASA Astrophysics Data System (ADS)

    Butter, Anja; Éboli, Oscar J. P.; Gonzalez-Fraile, J.; Gonzalez-Garcia, M. C.; Plehn, Tilman; Rauch, Michael

    2016-07-01

    The effective Lagrangian expansion provides a framework to study effects of new physics at the electroweak scale. To make full use of LHC data in constraining higher-dimensional operators we need to include both the Higgs and the electroweak gauge sector in our study. We first present an analysis of the relevant di-boson production LHC results to update constraints on triple gauge boson couplings. Our bounds are several times stronger than those obtained from LEP data. Next, we show how in combination with Higgs measurements the triple gauge vertices lead to a significant improvement in the entire set of operators, including operators describing Higgs couplings.

  18. The ATLAS Experiment: Getting Ready for the LHC

    SciTech Connect

    Jenni, Peter

    2006-05-15

    At CERN the Large Hadron Collider (LHC) project is well advanced. First proton-proton collisions at the high-energy frontier are expected for the second half of 2007. In parallel to the collider construction the powerful general-purpose ATLAS detector is being assembled in its underground cavern by a world-wide collaboration. ATLAS will explore new domains of particle physics. After briefly overviewing the LHC construction and installation progress, the status of the ATLAS experiment will be presented, including examples of the exciting prospects for new physics.

  19. Polarisation of electroweak gauge bosons at the LHC

    NASA Astrophysics Data System (ADS)

    Stirling, James; Vryonidou, Eleni

    2013-05-01

    We present results for the polarisation of gauge bosons produced at the LHC. Polarisation effects for W bosons manifest themselves in the angular distributions of the lepton and in the distributions of lepton transverse momentum and missing transverse energy. The polarisation is discussed for a range of different processes producing W bosons such as W+jets and W from top production. The relative contributions of the different polarisation states vary from process to process, reflecting the dynamics of the underlying hardscattering process. We also calculate the polarisation of the Z boson produced in association with QCD jets at the LHC.

  20. FELIX. A full acceptance detector at the LHC

    NASA Astrophysics Data System (ADS)

    Avati, V.; Eggert, K.; Taylor, C.

    1999-03-01

    The FELIX collaboration has proposed the construction of a full acceptance detector for the LHC, to be located at Intersection Region 4, and to be commissioned concurrently with the LHC. The primary mission of FELIX is QCD: to provide comprehensive and definitive observations of a very broad range of strong-interaction processes. This paper reviews the detector concept and performance characteristics, the physics menu, and plans for integration of FELIX into the collider lattice and physical environment. The current status of the FELIX Letter of Intent is discussed.

  1. Lepton Number Violation in Higgs Decay at LHC

    NASA Astrophysics Data System (ADS)

    Maiezza, Alessio; Nemevšek, Miha; Nesti, Fabrizio

    2015-08-01

    We show that within the left-right symmetric model, lepton number violating decays of the Higgs boson can be discovered at the LHC. The process is due to the mixing of the Higgs boson with the triplet that breaks parity. As a result, the Higgs boson can act as a gateway to the origin of the heavy Majorana neutrino mass. To assess the LHC reach, a detailed collider study of the same-sign dileptons plus jets channel is provided. This process is complementary to the existing nuclear and collider searches for lepton number violation and can probe the scale of parity restoration even beyond other direct searches.

  2. Probing minimal flavor violation at the CERN LHC

    SciTech Connect

    Grossman, Yuval; Nir, Yosef; Volansky, Tomer; Thaler, Jesse; Zupan, Jure

    2007-11-01

    If the LHC experiments discover new particles that couple to the standard model fermions, then measurements by ATLAS and CMS can contribute to our understanding of the flavor puzzles. We demonstrate this statement by investigating a scenario where extra SU(2)-singlet down-type quarks are within the LHC reach. By measuring masses, production cross sections, and relative decay rates, minimal flavor violation (MFV) can in principle be excluded. Conversely, these measurements can probe the way in which MFV applies to the new degrees of freedom. Many of our conclusions are valid in a much more general context than this specific extension of the standard model.

  3. New signature for color octet pseudoscalars at the CERN LHC

    SciTech Connect

    Zerwekh, Alfonso R.; Dib, Claudio O.; Rosenfeld, Rogerio

    2008-05-01

    Color octet (pseudo)scalars, if they exist, will be copiously produced at the CERN Large Hadron Collider (LHC). However, their detection can become a very challenging task. In particular, if their decay into a pair of top quarks is kinematically forbidden, the main decay channel would be into two jets, with a very large background. In this brief report we explore the possibility of using anomaly-induced decays of the color octet pseudoscalars into gauge bosons to find them at the LHC.

  4. Gluon saturation and inclusive hadron production at LHC

    SciTech Connect

    Levin, Eugene; Rezaeian, Amir H.

    2010-07-01

    In high-density QCD the hadron production stems from decay of mini jets that have the transverse momenta of the order of the saturation scale. It is shown in this paper that this idea is able to describe in a unique fashion both the inclusive hadron production for {radical}(s){>=}546 GeV including the first data from LHC and the deep inelastic scattering at HERA. Recently reported data from ALICE, CMS, and ATLAS including inclusive charged-hadron transverse momentum and multiplicity distribution in pp collisions are well described in our approach. We provide predictions for the upcoming LHC measurements.

  5. Checks of asymptotia in pp elastic scattering at LHC

    NASA Astrophysics Data System (ADS)

    Grau, Agnes; Pacetti, Simone; Pancheri, Giulia; Srivastava, Yogendra N.

    2012-07-01

    We parametrize TOTEM data for the elastic differential pp cross section at √{s}=7 TeV in terms of two exponentials with a relative phase. We employ two previously derived sum rules for pp elastic scattering amplitude in impact parameter space to check whether asymptotia has been reached at the LHC. A detailed study of the TOTEM data for the elastic differential cross section at √{s}=7 TeV is made and it is shown that, within errors, the asymptotic sum rules are satisfied at LHC. We propose to use this parametrization to study forthcoming higher energy data.

  6. Cold matter effects and quarkonium production at RHIC and LHC

    SciTech Connect

    Dos Santos, G. S.; Mariotto, C. B.; Goncalves, V. P.

    2013-03-25

    In this work we investigate two cold matter effects in J/{Psi} and {Upsilon} production in nuclear collisions at RHIC and LHC, namely the shadowing effect and nuclear absorption. We characterize these effects by estimating the rapidity dependence of some nuclear ratios in pA and AA collisions at RHIC and LHC, R{sub pA} = d{sigma}{sub pA}(J/{Psi},{Upsilon})/Ad{sigma}{sub pp}(J/{Psi},{Upsilon}) and R{sub AA} = d{sigma}{sub AA}(J/{Psi},{Upsilon})/A{sup 2}d{sigma}{sub pp}(J/{Psi},{Upsilon}).

  7. Top channel for early supersymmetry discovery at the LHC

    SciTech Connect

    Kane, Gordon L.; Kuflik, Eric; Lu, Ran; Wang, Lian-Tao

    2011-11-01

    Arguably the best-motivated channel for early LHC discovery is events including a high multiplicity of third generation quarks, such as four top quarks. For example generic string theories compactified to four dimensions with stabilized moduli typically have light gluinos with large branching ratios to t- and b-quarks. We analyze signals and background at 7 TeV LHC energy for 1 fb{sup -1} integrated luminosity, suggesting a reach for gluinos of about 650 GeV. A non-standard model signal from counting b-jets and leptons is robust, and provides information on the gluino mass, cross section, and spin.

  8. Vector boson fusion searches for dark matter at the LHC

    NASA Astrophysics Data System (ADS)

    Brooke, James; Buckley, Matthew R.; Dunne, Patrick; Penning, Bjoern; Tamanas, John; Zgubič, Miha

    2016-06-01

    The vector boson fusion (VBF) event topology at the Large Hadron Collider (LHC) allows efficient suppression of dijet backgrounds and is therefore a promising target for new physics searches. We consider dark matter models which interact with the standard model through the electroweak sector—either through new scalar and pseudoscalar mediators which can be embedded into the Higgs sector or via effective operators suppressed by some higher scale—and therefore have significant VBF production cross sections. Using realistic simulations of the ATLAS and CMS analysis chain, including estimates of major error sources, we project the discovery and exclusion potential of the LHC for these models over the next decade.

  9. Magnetic direction.

    PubMed

    Duchene, Pam; Muhm, John B

    2005-01-01

    In April 2005, the American Nurses Association (ANA) awarded St. Joseph Hospital, Nashua, NH, its highest honor for excellence in nursing: "Magnet Recognition." The Magnet Recognition Program was developed by the ANA's American Nurses Credentialing Center in the early 1980s to recognize health care organizations that provide the best in nursing care and uphold the tradition of excellence in professional nursing practice. St. Joseph began pursuing Magnet status more than three years ago, starting with a number of enhancements to nursing practices. The hospital worked hard to improve nurse-to-patient staffing and included many of its nurses on the nursing quality council, division advisory, and cultural diversity committees. Magnet program appraisers visited the hospital this January to conduct an intensive, on-site three-day examination. They interviewed patients, staff nurses, physicians, hospital employees, administrators, board members, and nursing leadership to evaluate St. Joseph's nursing care, services, and delivery of care to patients and their families. Soon after, Magnet status was bestowed. PMID:16350902

  10. Study of the Half-Day/Full-Day Kindergarten Model

    ERIC Educational Resources Information Center

    McInroy, Thomas R.

    2012-01-01

    This case study and problem analysis was an in-depth investigation of the half-day/full-day kindergarten model by utilizing interviews and focus groups to provide insight from parents, teachers, and other district personnel as to how the model has impacted the social, emotional, and academic development of the participating students. This study…

  11. Rethinking the Day of Silence

    ERIC Educational Resources Information Center

    Murphy, Adriana

    2013-01-01

    Back in 2006, 7th and 8th graders at Green Acres, the K-8 independent school where the author taught in suburban Maryland, participated in the Day of Silence. The Day of Silence is a national event: Students across the country take a one-day pledge of silence to show that they want to make schools safe for all students, regardless of their sexual…

  12. Sun-Earth Day, 2001

    NASA Technical Reports Server (NTRS)

    Adams, Mitzi L.; Mortfield, P.; Hathaway, D. H.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    To promote awareness of the Sun-Earth connection, NASA's Marshall Space Flight Center, in collaboration with the Stanford SOLAR Center, sponsored a one-day Sun-Earth Day event on April 27, 2001. Although "celebrated" on only one day, teachers and students from across the nation, prepared for over a month in advance. Workshops were held in March to train teachers. Students performed experiments, results of which were shared through video clips and an internet web cast. Our poster includes highlights from student experiments (grades 2 - 12), lessons learned from the teacher workshops and the event itself, and plans for Sun-Earth Day 2002.

  13. W physics at the LHC with FEWZ 2.1

    NASA Astrophysics Data System (ADS)

    Quackenbush, Seth; Gavin, Ryan; Li, Ye; Petriello, Frank

    2013-01-01

    We present an updated version of the FEWZ (Fully Exclusive W and Z production) code for the calculation of W± and γ∗/Z production at next-to-next-to-leading order in the strong coupling. Several new features and observables are introduced, and an order-of-magnitude speed improvement over the performance of FEWZ 2.0 is demonstrated. New phenomenological results for W± production and comparisons with LHC data are presented, and used to illustrate the range of physics studies possible with the features of FEWZ 2.1. We demonstrate with an example the importance of directly comparing fiducial-region measurements with theoretical predictions, rather than first extrapolating them to the full phase space. Program summaryProgram title: FEWZ 2.1 Catalogue identifier: AEJP_v1_1 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEJP_v1_1.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 12003230 No. of bytes in distributed program, including test data, etc.: 769 Distribution format: tar.gz Programming language: Fortran 77, C++, Python 2.4. Computer: x86/x86-64. Operating system: Unix/Linux, Mac OSX. RAM: 200 Mbytes Classification: 11.1. External routines: CUBA (included), LHAPDF (optional) Catalogue identifier of previous version: AEJP_v1_0 Journal reference of previous version: Comput. Phys. Comm. 182 (2011) 2388 Does the new version supersede the previous version?: Yes Nature of problem: Calculation of hadroproduction of W bosons, with differential distributions, at next-to-next-to-leading order in the strong coupling. Solution method: Integral reduction, sector decomposition, numerical integration Reasons for new version: Reintroduction of W boson to FEWZ 2 Summary of revisions: Addition of W boson production, now can run in W or Z/gamma mode. LHAPDF interface added. Large

  14. Multicore job scheduling in the Worldwide LHC Computing Grid

    NASA Astrophysics Data System (ADS)

    Forti, A.; Pérez-Calero Yzquierdo, A.; Hartmann, T.; Alef, M.; Lahiff, A.; Templon, J.; Dal Pra, S.; Gila, M.; Skipsey, S.; Acosta-Silva, C.; Filipcic, A.; Walker, R.; Walker, C. J.; Traynor, D.; Gadrat, S.

    2015-12-01

    After the successful first run of the LHC, data taking is scheduled to restart in Summer 2015 with experimental conditions leading to increased data volumes and event complexity. In order to process the data generated in such scenario and exploit the multicore architectures of current CPUs, the LHC experiments have developed parallelized software for data reconstruction and simulation. However, a good fraction of their computing effort is still expected to be executed as single-core tasks. Therefore, jobs with diverse resources requirements will be distributed across the Worldwide LHC Computing Grid (WLCG), making workload scheduling a complex problem in itself. In response to this challenge, the WLCG Multicore Deployment Task Force has been created in order to coordinate the joint effort from experiments and WLCG sites. The main objective is to ensure the convergence of approaches from the different LHC Virtual Organizations (VOs) to make the best use of the shared resources in order to satisfy their new computing needs, minimizing any inefficiency originated from the scheduling mechanisms, and without imposing unnecessary complexities in the way sites manage their resources. This paper describes the activities and progress of the Task Force related to the aforementioned topics, including experiences from key sites on how to best use different batch system technologies, the evolution of workload submission tools by the experiments and the knowledge gained from scale tests of the different proposed job submission strategies.

  15. Double Pomeron Exchange: from the ISR to the LHC

    SciTech Connect

    Albrow, Michael; /Fermilab

    2010-09-01

    I discuss Double Pomeron Exchange processes from their first observation at the CERN Intersecting Storage Rings, focusing on glueball searches, through the observations of exclusive {chi}{sub c0}, {gamma}{gamma} and di-jets at the Tevatron, to prospects at the LHC for exclusive Higgs boson production.

  16. First results of the LHC longitudinal density monitor

    NASA Astrophysics Data System (ADS)

    Jeff, A.; Boccardi, A.; Bravin, E.; Fisher, A. S.; Lefevre, T.; Rabiller, A.; Roncarolo, F.; Welsch, C. P.

    2011-12-01

    The Large Hadron Collider (LHC) at CERN is the world's largest particle accelerator. It is designed to accelerate and collide protons or heavy ions up to the center-of-mass energies of 14 TeV. Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, in particular to check the injection quality and to measure the proportion of charge outside the nominally filled bunches during the physics periods. In order to study this so-called ghost charge at levels very much smaller than the main bunches, a longitudinal profile measurement with a very high dynamic range is needed. A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotron light by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotron light diagnostics to be used with both protons and heavy ions. A prototype was installed during the 2010 LHC run and was able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 105 to be achieved. First measurements with the LDM are presented here along with an analysis of its performance and an outlook for future upgrades.

  17. LHC Beam Diffusion Dependence on RF Noise: Models And Measurements

    SciTech Connect

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Van Winkle, D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /CERN

    2010-09-14

    Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work. During a long store, the relation between the energy lost to synchrotron radiation and the noise injected to the beam by the RF accelerating voltage determines the growth of the bunch energy spread and longitudinal emittance. Since the proton synchrotron radiation in the LHC is very low, the beam diffusion is extremely sensitive to RF perturbations. The theoretical formalism presented in [1], suggests that the noise experienced by the beam depends on the cavity phase noise power spectrum, filtered by the beam transfer function, and aliased due to the periodic sampling of the accelerating voltage signal V{sub c}. Additionally, the dependence of the RF accelerating cavity noise spectrum on the Low Level RF (LLRF) configurations has been predicted using time-domain simulations and models [2]. In this work, initial measurements at the LHC supporting the above theoretical formalism and simulation predictions are presented.

  18. Combining LEP and LHC to bound the Higgs width

    NASA Astrophysics Data System (ADS)

    Englert, Christoph; McCullough, Matthew; Spannowsky, Michael

    2016-01-01

    The correlation of on- and off-shell Higgs boson production at the LHC in gg →h* → ZZ has been used to bound the Higgs width. We propose an alternative complementary constraint which is only possible through the combination of LEP and LHC measurements. Precision electroweak measurements at LEP allow for the determination of indirect constraints on Higgs couplings to vector bosons by considering one-loop processes involving virtual Higgs exchange. As the indirect constraint is model dependent we will consider two specific models which modify the Higgs couplings and width, and our results will apply specifically to these models. By combining these LEP constraints with current LHC 8 TeV Higgs measurements a stronger limit on the Higgs width can be achieved than with LHC data alone. Looking to the future, a more robust constraint can be achieved by correlating LEP measurements with WBF Higgs production followed by Higgs decays to WW and ZZ. We will discuss the model dependence of this method in comparison to other proposed methods.

  19. Analysis of optics designs for the LHC IR upgrade

    SciTech Connect

    Sen, Tanaji; Johnstone, John; /Fermilab

    2007-06-01

    We consider the different options proposed for the LHC IR upgrade. The two main categories: quadrupoles first (as in the baseline design) and dipoles-first have complementary strengths. We analyze the potential of the proposed designs by calculating important performance parameters. We also propose a local scheme for correcting the quadratic chromaticity.

  20. Searching for radiative neutrino mass generation at the LHC

    NASA Astrophysics Data System (ADS)

    Volkas, Raymond R.

    2015-04-01

    In this talk (talk given at the International Conference on Massive Neutrinos, Singapore, 9-13 February 2015), I describe the general characteristics of radiative neutrino mass models that can be probed at the LHC. I then cover the specific constraints on a new, explicit model of this type.

  1. ALICE and The state of matter at LHC

    ScienceCinema

    None

    2011-10-06

    Assembly and installation of ALICE, the LHC heavy ion experiment dedicated to the study of matter at extreme temperature and pressure, is nearing completion and the commissioning of the detector is well under way. A good time to look back, to the making of ALICE, and to look forward, to the first physics with proton and heavy ion beams.

  2. Hadronic and electromagnetic fragmentation of ultrarelativistic heavy ions at LHC

    NASA Astrophysics Data System (ADS)

    Braun, H. H.; Fassò, A.; Ferrari, A.; Jowett, J. M.; Sala, P. R.; Smirnov, G. I.

    2014-02-01

    Reliable predictions of yields of nuclear fragments produced in electromagnetic dissociation and hadronic fragmentation of ion beams are of great practical importance in analyzing beam losses and interactions with the beam environment at the Large Hadron Collider (LHC) at CERN as well as for estimating radiation effects of galactic cosmic rays on the spacecraft crew and electronic equipment. The model for predicting the fragmentation of relativistic heavy ions is briefly described, and then applied to problems of relevance for LHC. The results are based on the fluka code, which includes electromagnetic dissociation physics and dpmjet-iii as hadronic event generator. We consider the interaction of fully stripped lead ions with nuclei in the energy range from about one hundred MeV to ultrarelativistic energies. The yields of fragments close in the mass and charge to initial ions are calculated. The approach under discussion provides a good overall description of Pb fragmentation data at 30 and 158A GeV as well as recent LHC data for √sNN =2.76 TeV Pb-Pb interactions. Good agreement with the calculations in the framework of different models is found. This justifies application of the developed simulation technique both at the LHC injection energy of 177A GeV and at its collision energies of 1.38, 1.58, and 2.75A TeV, and gives confidence in the results obtained.

  3. Global parton distributions for the LHC Run II

    NASA Astrophysics Data System (ADS)

    Ball, R. D.

    2016-07-01

    We review the next generation global PDF sets: NNPDF3.0, MMHT14 and CT14. We describe the global datasets, particularly the new data from LHC Run I, the developments in QCD theory and PDF methodology, recent improvements in their combination and delivery, and future prospects for parton determination at Run II.

  4. CERN and LHC - their place in global science

    ScienceCinema

    None

    2011-10-06

    The Large Hadron Collider (LHC) is the largest scientific instrument in the world. It brings into collision intense beams of protons and ions to explore the structure of matter and investigate the forces of nature at an unprecedented energy scale, thus serving a community of some 7,000 particle physicists from all over the world.

  5. Unparticle physics in diphoton production at the CERN LHC

    SciTech Connect

    Kumar, M. C.; Mathews, Prakash

    2008-03-01

    We have considered the diphoton production in the unparticle physics at the LHC. The contributions of spin-0 and spin-2 unparticles to the diphoton production are studied in the invariant mass and other kinematical distributions, along with their dependencies on the model dependent parameters. It is found that the signal corresponding to the unparticles is significant for moderate values of the couplings.

  6. Some interesting min-bias distributions for early LHC runs

    SciTech Connect

    Skands, P.Z.; /CERN /Fermilab

    2007-12-01

    A few observable distributions in min-bias (inelastic, non-diffractive) events which could be well constrained with early LHC data are presented, with some comments on their significance for placing constraints on theoretical models. The effects of fiducial cuts (p{perpendicular} > 0.5 GeV, |{eta}| < 2.5) and extrapolation from the Tevatron are illustrated.

  7. Neutral currents production in LHC for 331 models

    SciTech Connect

    Martinez, R.; Ochoa, F.

    2010-07-29

    A brief review about the production of a Z' resonance in the framework of the 331 models is given. Their signatures at CERN LHC is highlighted by studying the Z' production and decay features, including different final states and one-loop corrections.

  8. Forward physics using proton tagging at the LHC

    SciTech Connect

    Royon, Christophe

    2015-04-10

    We describe different physics topics that can be performed at the LHC using tagged intact protons leading to a better understanding of the Pomeron structure in terms of quarks and gluons and to unprecedented sensitivities to quartic anomalous couplings between γ and W/Z bosons.

  9. Magnetic holes in the solar wind. [(interplanetary magnetic fields)

    NASA Technical Reports Server (NTRS)

    Turner, J. M.; Burlaga, L. F.; Ness, N. F.; Lemaire, J. F.

    1976-01-01

    An analysis is presented of high resolution interplanetary magnetic field measurements from the magnetometer on Explorer 43 which showed that low magnetic field intensities in the solar wind at 1 AU occur as distinct depressions or 'holes'. These magnetic holes are new kinetic-scale phenomena, having a characteristic dimension on the order of 20,000 km. They occurred at a rate of 1.5/day in the 18-day time span (March 18 to April 6, 1971) that was analyzed. Most of the magnetic holes are characterized by both a depression in the absolute value of the magnetic field, and a change in the magnetic field direction; some of these are possibly the result of magnetic merging. However, in other cases the magnetic field direction does not change; such holes are not due to magnetic merging, but might be a diamagnetic effect due to localized plasma inhomogeneities.

  10. Using Solid State Disk Array as a Cache for LHC ATLAS Data Analysis

    NASA Astrophysics Data System (ADS)

    Yang, W.; Hanushevsky, A. B.; Mount, R. P.; Atlas Collaboration

    2014-06-01

    User data analysis in high energy physics presents a challenge to spinning-disk based storage systems. The analysis is data intense, yet reads are small, sparse and cover a large volume of data files. It is also unpredictable due to users' response to storage performance. We describe here a system with an array of Solid State Disk as a non-conventional, standalone file level cache in front of the spinning disk storage to help improve the performance of LHC ATLAS user analysis at SLAC. The system uses several days of data access records to make caching decisions. It can also use information from other sources such as a work-flow management system. We evaluate the performance of the system both in terms of caching and its impact on user analysis jobs. The system currently uses Xrootd technology, but the technique can be applied to any storage system.

  11. The first magnetic chart

    NASA Astrophysics Data System (ADS)

    Clark, Toby; Barraclough, David

    2001-02-01

    Almost 300 years to the day since Edmond Halley's first magnetic chart, the RAS held a Discussion Meeting to commemorate this achievement and to consider Halley's work in navigation and geophysics. David Barraclough and Toby Clark report on the ``300th anniversary of the first magnetic chart: Edmond Halley's work in geophysics and navigation''.

  12. Instrumentation and Quench Protection for LARP Nb3Sn Magnets

    SciTech Connect

    Felice, H.; Ambrosio, G.; Chlachidize, G.; Ferracin, P.; Hafalia, R.; Hannaford, R. C.; Joseph, J.; Lietzke, A.; McInturff, A.; Muratore, J.; Prestemon, S.; Sabbi, G. L.; Schmalzle, J.; Wanderer, P.; Wang, X.

    2008-08-17

    The US LHC Accelerator Research Program (LARP) is developing Nb{sub 3}Sn prototype quadrupoles for the LHC interaction region upgrades. Several magnets have been tested within this program and understanding of their behavior and performance is a primary goal. The instrumentation is consequently a key consideration, as is protection of the magnet during quenches. In all LARP magnets, the flexible circuits traces combine the instrumentation and the protection heaters. Their fabrication relies on printed circuit technology based on a laminate made of a 45-micron thick kapton sheet and a 25-micron thick foil of stainless steel. This paper reviews the protection heaters designs used in the TQ (Technology Quadrupole) and LR (Long Racetrack) series as well as the one used in LBNL HD2a high field dipole and presents the design of the traces for the Long Quadrupole (LQ), addressing challenges associated with the stored energy and the length of the magnet.

  13. Day Care Infection Control Protocol.

    ERIC Educational Resources Information Center

    Seattle-King County Dept. of Public Health, Seattle, WA.

    This day care infection control manual was assembled to provide technical guidance for the prevention and control of communicable diseases to child day care facilities in Seattle and King County, Washington. For each disease, the manual provides background information, public health control recommendations, and letters that can be used to…

  14. Youth Field Day Planning Guide.

    ERIC Educational Resources Information Center

    Wisconsin State Dept. of Natural Resources, Madison.

    Youth field days expose children to outdoor activities, land use ethics, and habitat conservation and encourage adults to be mentors in these areas. A typical youth field day could have programs in archery, fishing, boating, shooting, or safety. The event requires a diverse steering committee that usually includes sporting clubs and state…

  15. Day Care Center Enrichment Program.

    ERIC Educational Resources Information Center

    West Virginia State Dept. of Welfare, Charleston.

    This guide to a West Virginia Department of Welfare project for upgrading the quality of day care centers throughout the state presents samples of the forms used in the program, accompanied by a brief description of the program's format, requirements and procedures. The Day Care Center Enrichment Program provides a monetary incentive for…

  16. Day Care for America's Children.

    ERIC Educational Resources Information Center

    LaCrosse, E. Robert

    High quality day care is a pressing social need for the 1970's. Factors responsible for the strong interest in day care include pressures for welfare reform, the growing number of women in the labor force, minority pressures for equal opportunities, and research findings stressing the importance of development during the early years of a child's…

  17. In Defense of Snow Days

    ERIC Educational Resources Information Center

    Goodman, Joshua

    2015-01-01

    In snowy climates, school superintendents must frequently decide whether an impending storm warrants closing schools for the day. Concerns about student and teacher safety must be weighed against the loss of student learning time, along with state requirements for days of instruction and the cost and inconvenience of extending the school year into…

  18. Montessori All Day, All Year

    ERIC Educational Resources Information Center

    Black, Connie; Davis, Liza

    2015-01-01

    Introducing real community into the Children's House goes back to the roots of Montessori education through all-day Montessori. The all-day environment is a house where children live with a "developmental room" of Montessori materials including a living room, kitchen, dining area, bedroom, bathroom, greeting rooms, and outdoor spaces.…

  19. Day Care and the Schools.

    ERIC Educational Resources Information Center

    Caldwell, Bettye M.

    1981-01-01

    Although it has always been considered the "poor relation" of early childhood education, day care in the public schools is the most effective way of establishing a continuity between the preschool and the elementary school. The Kramer Model of "extended day school" is a cooperative venture between a college and a public school. (JN)

  20. Impact evaluation of environmental and geometrical parasitic effects on high-precision position measurement of the LHC collimator jaws

    NASA Astrophysics Data System (ADS)

    Danisi, Alessandro; Losito, Roberto; Masi, Alessandro

    2015-09-01

    Measuring the apertures of the Large Hadron Collider (LHC) collimators, as well as the positions of their axes, is a challenging task. The LHC collimators are equipped with high-precision linear position sensors, the linear variable differential transformers (LVDTs). The accuracy of such sensors is limited by the peculiar parasitic effect of being rather sensitive to external magnetic fields. A new type of inductive sensor, the Ironless Inductive Position Sensor (I2PS), that keeps the advantages of the LVDTs but is insensitive to external magnetic fields has been designed, constructed, and tested at CERN. For this sensor, a detailed description of parasitic effects such as high-frequency capacitances and the presence of conductive shields and electric motor, in the surroundings is given, from analytical, numerical, and experimental viewpoints. In addition, proof is given of the I2PS’s radiation hardness. The aim of this paper is to give a complete and exhaustive impact evaluation, from the metrological viewpoint, of these parasitic effects on these two fundamental sensor solutions.