ERL-BASED LEPTON-HADRON COLLIDERS: eRHIC AND LHeC

CERN Document Server

Zimmermann, F

2013-01-01

Two hadron-ERL colliders are being proposed. The Large Hadron electron Collider (LHeC) plans to collide the high-energy protons and heavy ions in the Large Hadron Collider (LHC) at CERN with 60-GeV polarized electrons or positrons. The baseline scheme for this facility adds to the LHC a separate recirculating superconducting (SC) lepton linac with energy recovery, delivering a lepton current of 6.4mA. The electron-hadron collider project eRHIC aims to collide polarized (and unpolarized) electrons with a current of 50 (220) mA and energies in the range 5–30 GeV with a variety of hadron beams— heavy ions as well as polarized light ions— stored in the existing Relativistic Heavy Ion Collider (RHIC) at BNL. The eRHIC electron beam will be generated in an energy recovery linac (ERL) installed inside the RHIC tunnel.

Large Hadron Collider

CERN Multimedia

2007-01-01

"In the spring 2008, the Large Hadron Collider (LHC) machine at CERN (the European Particle Physics laboratory) will be switched on for the first time. The huge machine is housed in a circular tunnel, 27 km long, excavated deep under the French-Swiss border near Geneva." (1,5 page)

Physics at Hadronic Colliders (4/4)

CERN Multimedia

CERN. Geneva

2008-01-01

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

Physics at Hadronic Colliders (1/4)

CERN Multimedia

CERN. Geneva

2008-01-01

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

Physics at Hadronic Colliders (2/4)

CERN Multimedia

CERN. Geneva

2008-01-01

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

Physics at Hadronic Colliders (3/4)

CERN Multimedia

CERN. Geneva

2008-01-01

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

Flavorful leptoquarks at hadron colliders

Science.gov (United States)

Hiller, Gudrun; Loose, Dennis; Nišandžić, Ivan

2018-04-01

B -physics data and flavor symmetries suggest that leptoquarks can have masses as low as a few O (TeV ) , predominantly decay to third generation quarks, and highlight p p →b μ μ signatures from single production and p p →b b μ μ from pair production. Abandoning flavor symmetries could allow for inverted quark hierarchies and cause sizable p p →j μ μ and j j μ μ cross sections, induced by second generation couplings. Final states with leptons other than muons including lepton flavor violation (LFV) ones can also arise. The corresponding couplings can also be probed by precision studies of the B →(Xs,K*,ϕ )e e distribution and LFV searches in B -decays. We demonstrate sensitivity in single leptoquark production for the large hadron collider (LHC) and extrapolate to the high luminosity LHC. Exploration of the bulk of the parameter space requires a hadron collider beyond the reach of the LHC, with b -identification capabilities.

LHC suppliers win Golden Hadron awards

CERN Multimedia

Maximilien Brice

2004-01-01

In a ceremony on 30 July, three of the 200 suppliers for the Large Hadron Collider (LHC) were presented with Golden Hadron awards. It is the third year that the awards have been presented to suppliers, not only for their technical and financial achievements but also for their compliance with contractual deadlines. This year the three companies are all involved in the supplies for the LHC's main magnet system.

CERN-Fermilab Hadron Collider Physics Summer School

CERN Multimedia

2007-01-01

Applications are now open for the 2nd CERN-Fermilab Hadron Collider Physics Summer School, which will take place at CERN from 6 to 15 June 2007. The school web site is http://cern.ch/hcpss with links to the academic program and application procedure. The application deadline is 9 March 2007. The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, covered extensively the physics at the Tevatron collider experiments. The second school to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be given on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be  supported by in-depth discussion sess...

Large Hadron Collider nears completion

CERN Multimedia

2008-01-01

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

Exergy Analysis of the Cryogenic Helium Distribution System for the Large Hadron Collider (LHC)

CERN Document Server

Claudet, S; Tavian, L; Wagner, U

2010-01-01

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..

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

International Nuclear Information System (INIS)

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

2010-01-01

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.

Considerations on Energy Frontier Colliders after LHC

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2016-11-15

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

Beyond the Large Hadron Collider: A First Look at Cryogenics for CERN Future Circular Colliders

Science.gov (United States)

Lebrun, Philippe; Tavian, Laurent

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

Higgs physics at the Large Hadron Collider

Indian Academy of Sciences (India)

Higgs boson; Large Hadron Collider; electroweak symmetry; spin and CP of the Higgs boson ... I shall then give a short description of the pre-LHC constraints on the Higgs mass and the theoretical predictions for the LHC along with a discussion of the current experimental results, ending with prospects in the near future at ...

The future of the Large Hadron Collider and CERN.

Science.gov (United States)

Heuer, Rolf-Dieter

2012-02-28

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

2nd CERN-Fermilab Hadron Collider Physics Summer School

CERN Document Server

2007-01-01

June 6-15, 2007, CERN The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 9 MARCH 2007 The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, extensively covered the physics at the Tevatron collider experiments. The second school, to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be placed on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be supported by in-depth discussion sessions and will include the theory and phenomenology of hadron collisions, discovery physics topics, detector and analysis t...

Large Hadron Collider commissioning and first operation.

Science.gov (United States)

Myers, S

2012-02-28

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

Top production at hadron colliders

Indian Academy of Sciences (India)

New results on top quark production are presented from four hadron collider experiments: CDF and D0 at the Tevatron, and ATLAS and CMS at the LHC. Cross-sections for single top and top pair production are discussed, as well as results on the top–antitop production asymmetry and searches for new physics including ...

Large Area Silicon Tracking Detectors with Fast Signal Readout for the Large Hadron Collider (LHC) at CERN

CERN Document Server

Köstner, S

2005-01-01

The Standard Model of elementary particles, which is summarized briefly in the second chapter, incorporates a number of successful theories to explain the nature and consistency of matter. However not all building blocks of this model could yet be tested by experiment. To confirm existing theories and to improve nowadays understanding of matter a new machine is currently being built at CERN, the Large Hadron Collider (LHC), described in the third chapter. LHC is a proton-proton collider which will reach unprecedented luminosities and center of mass energies. Five experiments are attached to it to give answers to questions like the existence of the Higgs meson, which allows to explain the mass content of matter, and the origin of CP-violation, which plays an important role in the baryogenesis of the universe. Supersymmetric theories, proposing a bosonic superpartner for each fermion and vice versa, will be tested. By colliding heavy ions, high energy and particle densities can be achieved and probed. This stat...

A Large Hadron Electron Collider at CERN, Physics, Machine, Detector

CERN Document Server

Adolphson, C

2011-01-01

The physics programme and the design are described of a new electron-hadron collider, the LHeC, in which electrons of $60$ to possibly $140$\\,GeV collide with LHC protons of $7000$\\,GeV. With an $ep$ design luminosity of about $10^{33}$\\,cm$^{-2}$s$^{-1}$, the Large Hadron Electron Collider exceeds the integrated luminosity collected at HERA by two orders of magnitude and the kinematic range by a factor of twenty in the four-momentum squared, $Q^2$, and in the inverse Bjorken $x$. The physics programme is devoted to an exploration of the energy frontier, complementing the LHC and its discovery potential for physics beyond the Standard Model with high precision deep inelastic scattering (DIS) measurements. These are projected to solve a variety of fundamental questions in strong and electroweak interactions. The LHeC thus becomes the world's cleanest high resolution microscope, designed to continue the path of deep inelastic lepton-hadron scattering into unknown areas of physics and kinematics. The physics ...

Summary of the very large hadron collider physics and detector workshop

International Nuclear Information System (INIS)

Anderson, G.; Berger, M.; Brandt, A.; Eno, S.

1997-01-01

One of the options for an accelerator beyond the LHC is a hadron collider with higher energy. Work is going on to explore accelerator technologies that would make such a machine feasible. This workshop concentrated on the physics and detector issues associated with a hadron collider with an energy in the center of mass of the order of 100 to 200 TeV

LHC collider phenomenology of minimal universal extra dimensions

Science.gov (United States)

Beuria, Jyotiranjan; Datta, AseshKrishna; Debnath, Dipsikha; Matchev, Konstantin T.

2018-05-01

We discuss the collider phenomenology of the model of Minimal Universal Extra Dimensions (MUED) at the Large hadron Collider (LHC). We derive analytical results for all relevant strong pair-production processes of two level 1 Kaluza-Klein partners and use them to validate and correct the existing MUED implementation in the fortran version of the PYTHIA event generator. We also develop a new implementation of the model in the C++ version of PYTHIA. We use our implementations in conjunction with the CHECKMATE package to derive the LHC bounds on MUED from a large number of published experimental analyses from Run 1 at the LHC.

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

CERN Document Server

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

2011-01-01

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**34/cm**2s. 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 ...

Instrumentation Status of the Low-β Magnet Systems at the Large Hadron Collider (LHC)

CERN Document Server

Darve, C; Casas-Cubillos, J; Perin, A; Vauthier, N

2011-01-01

The low-β 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 1034cm-2s-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-β 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 in...

Upgrade of the ATLAS Hadronic Tile Calorimeter for the High Luminosity LHC

CERN Document Server

Hildebrand, Kevin; The ATLAS collaboration

2017-01-01

The Tile Calorimeter is the hadronic calorimeter covering the central region of the ATLAS detector at the Large Hadron Collider. It is a scintillator-steel sampling calorimeter read out via wavelength shifting fibers coupled to photomultiplier tubes (PMT). The PMT signals are digitized and stored on detector until a trigger is received. The Large Hadron Collider (LHC) has envisaged a series of upgrades towards a High Luminosity LHC (HL-LHC) delivering five times the LHC nominal instantaneous luminosity. The ATLAS Phase II upgrade (2024-2025) will accommodate the upgrade of the detector and data acquisition system for the HL-LHC. In particular, TileCal will undergo a major replacement of its on- and off-detector electronics. In the new architecture, all signals will be digitized and then transferred directly to the off-detector electronics, where the signals will be reconstructed, stored, and sent to the first level of trigger at the rate of 40 MHz. This will provide better precision of the calorimeter signals...

Upgrade of the ATLAS Hadronic Tile Calorimeter for the High Luminosity LHC

CERN Document Server

Hildebrand, Kevin; The ATLAS collaboration

2017-01-01

The Tile Calorimeter is the hadronic calorimeter covering the central region of the ATLAS detector at the Large Hadron Collider. It is a scintillator-steel sampling calorimeter read out via wavelength shifting fibers coupled to photomultiplier tubes (PMT). . The Large Hadron Collider (LHC) has envisaged a series of upgrades towards a High Luminosity LHC (HL-LHC) delivering five times the LHC nominal instantaneous luminosity. The ATLAS Phase II upgrade (2024-2025) will accommodate the upgrade of the detector and data acquisition system for the HL-LHC. In particular, TileCal will undergo a major replacement of its on- and off-detector electronics. In the new architecture, all signals will be digitized and sent to the first level of trigger at the rate of 40 MHz. This will provide better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Changes to the electronics will also contribute to the reliability and redundancy of the system. ...

Golden Hadron awards for the LHC's top suppliers.

CERN Multimedia

Maximilien Brice

2003-01-01

The following firms have been selected to receive a GOLDEN HADRON AWARD 2003, in recognition of their outstanding achievement: JDL TECHNOLOGIES, Belgium "in producing automatic cable inspection systems", FURUKAWA ELECTRIC COMPANY, Japan "in producing high quality superconducting cable", IHI Corporation, Japan, and LINDE KRYOTECHNIK, Switzerland "in producing novel 1.8 K refrigeration units based on advanced cold compressor technology" for the Large Hadron Collider.Photos 01, 02: Recipients of the 2003 Golden Hadron awards at the presentation ceremony on 16 May.Photo 03: LHC project leader Lyn Evans updates the award recipients on work for CERN's new accelerator.Photo 04: René Joannes of JDL Technologies (left) receives a Golden Hadron award from LHC project leader Lyn Evans.Shinichiro Meguro, managing director of Furukawa Electric Company, receives a Golden Hadron award from LHC project leader Lyn Evans.Photo 06: Kirkor Kurtcuoglu of Linde Kryotechnik (left) and Motoki Yoshinaga, associate director of IHI...

Naming Conventions for the Large Hadron Collider Project

CERN Document Server

Faugeras, Paul E

1997-01-01

This report gives the procedures for defining standard abbreviations for the various machine components of the Large Hadron Collider (LHC) Project, as well as for the surface buildings and the underground Civil Engineering works of the LHC. The contents of this report has been approved by the LHC Project Leader and is published in the form of a Project Report in order to allow its immediate implementation. It will be incorporated later in the Quality Assurance Plan of the LHC Project which is under preparation.

Higgs boson production at hadron colliders at N3LO in QCD

Science.gov (United States)

Mistlberger, Bernhard

2018-05-01

We present the Higgs boson production cross section at Hadron colliders in the gluon fusion production mode through N3LO in perturbative QCD. Specifically, we work in an effective theory where the top quark is assumed to be infinitely heavy and all other quarks are considered to be massless. Our result is the first exact formula for a partonic hadron collider cross section at N3LO in perturbative QCD. Furthermore, our result is an analytic computation of a hadron collider cross section involving elliptic integrals. We derive numerical predictions for the Higgs boson cross section at the LHC. Previously this result was approximated by an expansion of the cross section around the production threshold of the Higgs boson and we compare our findings. Finally, we study the impact of our new result on the state of the art prediction for the Higgs boson cross section at the LHC.

Silicon detectors operating beyond the LHC collider conditions: scenarios for radiation fields and detector degradation

International Nuclear Information System (INIS)

Lazanu, I.; Lazanu, S.

2004-01-01

Particle physics makes its greatest advances with experiments at the highest energies. The way to advance to a higher energy regime is through hadron colliders, or through non-accelerator experiments, as for example the space astroparticle missions. In the near future, the Large Hadron Collider (LHC) will be operational, and beyond that, its upgrades: the Super-LHC (SLHC) and the hypothetical Very Large Hadron Collider (VLHC). At the present time, there are no detailed studies for future accelerators, except those referring to LHC. For the new hadron collider LHC and some of its updates in luminosity and energy, the silicon detectors could represent an important option, especially for the tracking system and calorimetry. The main goal of this paper is to analyse the expected long-time degradation of the silicon as material and for silicon detectors, during continuous radiation, in these hostile conditions. The behaviour of silicon in relation to various scenarios for upgrade in energy and luminosity is discussed in the frame of a phenomenological model developed previously by the authors and now extended to include new mechanisms, able to explain and give solutions to discrepancies between model predictions and detector behaviour after hadron irradiation. Different silicon material parameters resulting from different technologies are considered to evaluate what materials are harder to radiation and consequently could minimise the degradation of device parameters in conditions of continuous long time operation. (authors)

Large Hadron particle collider may not have its run this November

CERN Multimedia

2007-01-01

"The Large Hadron Collider (LHC), based at CERN in Geneva, Switzerland, will not run in November this year as scheduled. The LHC was supposed to have a test run this yera, before switching on the scientific search for the Higgs boson in 2008."(1 page)

Destination Universe: The Incredible Journey of a Proton in the Large Hadron Collider

CERN Multimedia

Lefevre, C

2008-01-01

This brochure illustrates the incredible journey of a proton as he winds his way through the CERN accelerator chain and ends up inside the Large Hadron Collider (LHC). The LHC is CERN's flagship particle accelerator which can collide protons together at close to the speed of light, creating circumstances like those just seconds after the Big Bang.

Radiation protection considerations in the design of the LHC, CERN's large hadron collider

International Nuclear Information System (INIS)

Hoefert, M.; Huhtinen, M.; Moritz, L.E.; Nakashima, H.; Potter, K.M.; Rollet, S.; Stevenson, G.R.; Zazula, J.M.

1996-01-01

This paper describes the radiological concerns which are being taken into account in the design of the LHC (CERN's future Large Hadron Collider). The machine will be built in the 27 km circumference ring tunnel of the existing LEP collider at CERN. The high intensity of the circulating beams (each containing more than 10 14 protons at 7 TeV) determines the thickness specification of the shielding of the main-ring tunnel, the precautions to be taken in the design of the beam dumps and their associated caverns and the radioactivity induced by the loss of protons in the main ring by inelastic beam-gas interactions. The high luminosity of the collider is designed to provide inelastic collision rates of 10 9 per second in each of the two principal detector installations, ATLAS and CMS. These collisions determine the shielding of the experimental areas, the radioactivity induced in both the detectors and in the machine components on either side of the experimental installations and, to some extent, the radioactivity induced in the beam-cleaning (scraper) systems. Some of the environmental issues raised by the project will be discussed. (author)

The Large Hadron Collider in the LEP tunnel

International Nuclear Information System (INIS)

Brianti, G.; Huebner, K.

1987-01-01

The status of the studies for the CERN Large Hadron Collider (LHC) is described. This collider will provide proton-proton collisions with 16 TeV centre-of-mass energy and a luminosity exceeding 10 33 cm -2 s -1 per interaction point. It can be installed in the tunnel of the Large Electron-Positron Storage Ring (LEP) above the LEP elements. It will use superconducting magnets of a novel, compact design, having two horizontally separated channels for the two counter-rotating bunched proton beams, which can collide in a maximum of seven interaction points. Collisions between protons of the LHC and electrons of LEP are also possible with a centre-of-mass energy of up to 1.8 TeV and a luminosity of up to 2 x 10 32 cm -2 s -1 . (orig.)

Black Holes and the Large Hadron Collider

Science.gov (United States)

Roy, Arunava

2011-01-01

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

Electron cloud studies for the LHC and future proton colliders

CERN Document Server

Domínguez Sánchez de la Blanca, César Octavio; Zimmermann, Frank

2014-01-01

The Large Hadron Collider (LHC) is the world’s largest and most powerful particle collider. Its main objectives are to explore the validity of the standard model of particle physics and to look for new physics beyond it, at unprecedented collision energies and rates. A good luminosity performance is imperative to attain these goals. In the last stage of the LHC commissioning (2011-2012), the limiting factor to achieving the design bunch spacing of 25 ns has been the electron cloud effects. The electron cloud is also expected to be the most important luminosity limitation after the first Long Shut-Down of the LHC (LS1), when the machine should be operated at higher energy and with 25-ns spacing, as well as for the planned luminosity upgrade (HL-LHC) and future high energy proton colliders (HE-LHC and VHE-LHC). This thesis contributes to the understanding of the electron cloud observations during the first run of the LHC (2010-2012), presents the first beam dynamics analysis for the next generation of high en...

Design of the large hadron electron collider interaction region

Science.gov (United States)

Cruz-Alaniz, E.; Newton, D.; Tomás, R.; Korostelev, M.

2015-11-01

The large hadron electron collider (LHeC) is a proposed upgrade of the Large Hadron Collider (LHC) within the high luminosity LHC (HL-LHC) project, to provide electron-nucleon collisions and explore a new regime of energy and luminosity for deep inelastic scattering. The design of an interaction region for any collider is always a challenging task given that the beams are brought into crossing with the smallest beam sizes in a region where there are tight detector constraints. In this case integrating the LHeC into the existing HL-LHC lattice, to allow simultaneous proton-proton and electron-proton collisions, increases the difficulty of the task. A nominal design was presented in the the LHeC conceptual design report in 2012 featuring an optical configuration that focuses one of the proton beams of the LHC to β*=10 cm in the LHeC interaction point to reach the desired luminosity of L =1033 cm-2 s-1 . This value is achieved with the aid of a new inner triplet of quadrupoles at a distance L*=10 m from the interaction point. However the chromatic beta beating was found intolerable regarding machine protection issues. An advanced chromatic correction scheme was required. This paper explores the feasibility of the extension of a novel optical technique called the achromatic telescopic squeezing scheme and the flexibility of the interaction region design, in order to find the optimal solution that would produce the highest luminosity while controlling the chromaticity, minimizing the synchrotron radiation power and maintaining the dynamic aperture required for stability.

CERN Library | Mario Campanelli presents "Inside CERN's Large Hadron Collider" | 16 March

CERN Multimedia

CERN Library

2016-01-01

"Inside CERN's Large Hadron Collider" by Mario Campanelli. Presentation on Wednesday, 16 March at 4 p.m. in the Library (bldg 52-1-052) The book aims to explain the historical development of particle physics, with special emphasis on CERN and collider physics. It describes in detail the LHC accelerator and its detectors, describing the science involved as well as the sociology of big collaborations, culminating with the discovery of the Higgs boson.  Inside CERN's Large Hadron Collider  Mario Campanelli World Scientific Publishing, 2015  ISBN 9789814656641​

Discovering a Light Scalar or Pseudoscalar at The Large Hadron Collider

DEFF Research Database (Denmark)

Frandsen, Mads Toudal; Sannino, Francesco

2012-01-01

The allowed standard model Higgs mass range has been reduced to a region between 114 and 130 GeV or above 500 GeV, at the 99% confidence level, since the Large Hadron Collider (LHC) program started. Furthermore some of the experiments at Tevatron and LHC observe excesses that could arise from...

CERN-Fermilab Hadron Collider Physics Summer School 2013 open for applications

CERN Multimedia

2013-01-01

Mark your calendar for 28 August - 6 September 2013, when CERN will welcome students to the eighth CERN-Fermilab Hadron Collider Physics Summer School.   Experiments at hadron colliders will continue to provide our best tools for exploring physics at the TeV scale for some time. With the completion of the 7-8 TeV runs of the LHC, and the final results from the full Tevatron data sample becoming available, a new era in particle physics is beginning, heralded by the Higgs-like particle recently discovered at 125 GeV. To realize the full potential of these developments, CERN and Fermilab are jointly offering a series of "Hadron Collider Physics Summer Schools", to prepare young researchers for these exciting times. The school has alternated between CERN and Fermilab, and will return to CERN for the eighth edition, from 28 August to 6 September 2013. The CERN-Fermilab Hadron Collider Physics Summer School is an advanced school which particularly targets young postdocs in exper...

The large hadron collider beauty experiment calorimeters

International Nuclear Information System (INIS)

Martens, A.; LHCb Collaboration; Martens, A.

2010-01-01

The Large Hadron Collider beauty experiment (LHCb), one of the four largest experiments at the LHC at CERN, is dedicated to precision studies of CP violation and other rare effects, in particular in the b and c quark sectors. It aims at precisely measuring the Standard Model parameters and searching for effects inconsistent with this picture. The LHCb calorimeter system comprises a scintillating pad detector, a pre-shower (PS), electromagnetic (ECAL) and hadronic calorimeters, all of these employing the principle of transporting the light from scintillating layers with wavelength shifting fibers to photomultipliers. The fast response of the calorimeters ensures their key role in the LHCb trigger, which has to cope with the LHC collision rate of 40MHz. After discussing the design and expected performance of the LHCb calorimeter system, one addresses the time and energy calibration issues. The results obtained with the calorimeter system from the first LHC data will be shown.

Secondary particle background levels and effects on detectors at future hadron colliders

International Nuclear Information System (INIS)

Pal, T.

1993-01-01

The next generation of hadron colliders, the Superconducting Super Collider (SSC) and the Large Hadron Collider (LHC), will operate at high center-of-mass energies and luminosities. Namely, for the SSC(LHC) √s=40TeV (√s=16TeV) and L=10 33 cm -2 s -1 (L=3x10 34 cm -2 s -1 ). These conditions will result in the production of large backgrounds as well as radiation environments. Ascertaining the backgrounds, in terms of the production of secondary charged and neutral particles, and the radiation environments are important considerations for the detectors proposed for these colliders. An initial investigation of the radiation levels in the SSC detectors was undertaken by D. Groom and colleagues, in the context of the open-quotes task force on radiation levels in the SSC interaction regions.close quotes The method consisted essentially of an analytic approach, using standard descriptions of average events in conjunction with simulations of secondary processes

For Information: CERN-Fermilab2006 Hadron Collider Physics Summer School

CERN Multimedia

2006-01-01

Applications are Now Open for the CERN-Fermilab2006 Hadron Collider Physics Summer School August 9-18, 2006 Please go to the school web site http://hcpss.fnal.gov/ and follow the links to the Application process. The APPLICATION DEADLINE IS APRIL 8, 2006. Successful applicants and support awards will be announced shortly thereafter. Also available on the web is the tentative academic program of the school. The main goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers a broad picture of both the theoretical and experimental aspects of hadron collider physics. The emphasis of the first school will be on the physics potential of the first years of data taking at the LHC, and on the experimental and theoretical tools needed to exploit that potential. A series of lectures and informal discussions will include an introduction to the theoretical and phenomenological framework of hadron collisions, and current theoretical models of frontier physics, as...

The Large Hadron Collider of CERN and the roadmap toward higher performance

CERN Document Server

Rossi, L

2012-01-01

The Large Hadron Collider is exploring the new frontier of particle physics. It is the largest and most ambitious scientific instrument ever built and 100 years after the Rutherford experiment it continues that tradition of “smashing atoms” to unveil the secret of the infinitely small. LHC makes use of all what we learnt in 40 years of hadron colliders, in particular of ISR and Sp-pbarS at CERN and Tevatron at Fermilab, and it is based on Superconductivity, discovered also 100 years ago. Designing, developing the technology, building and finally commissioning the LHC took more than twenty years. While LHC is now successfully running, we are already preparing the future for the next step. First, by increasing of a factor five the LHC luminosity in ten years from now, and then by increasing its energy by a factor two or more, on the horizon of the next twenty years. These LHC upgrades, in luminosity and energy, will be the super-exploitation of the CERN infrastructure and is the best investment that the HEP...

Academic Training Lecture: Higgs Boson Searches at Hadron Colliders

CERN Multimedia

HR Department

2010-01-01

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

Large hadron collider workshop. Proceedings. Vol. 3

International Nuclear Information System (INIS)

Jarlskog, G.; Rein, D.

1990-01-01

The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentaiton and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

Large hadron collider workshop. Proceedings. Vol. 2

International Nuclear Information System (INIS)

Jarlskog, G.; Rein, D.

1990-01-01

The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol.1 of these proceedings contains the papers presented at the plenary sessions, Vol.2 the individual contributions to the physics sessions, and Vol.3 those to the instrumentation sessions. (orig.)

CERN to start Large Hadron Collider november 2007

CERN Multimedia

2006-01-01

"The Large Hadron Collider (LHC) is expected to provide its first collisions in November 2007, CERN has announced. A two-month run at 0.9 TeV is planned for 2007 to test the accelerating and detecting equipment, and a full power run at 14 TeV is expected in the spring of 2008."

Literature in focus - The Large Hadron Collider: A Marvel of Technology

CERN Document Server

Cecile Noels

Inside an insulating vacuum chamber in a tunnel about 100 metres below the surface of the Franco-Swiss plain near Geneva, packets of protons whirl around the 27-km circumference of the Large Hadron Collider (LHC) at a speed close to that of light, colliding every 25 nanoseconds at four beam crossing points. The products of these collisions, of which hundreds of billions will be produced each second, are observed and measured with the most advanced particle-detection technology, capable of tracking individual particles as they generate a signature track during their passage through the detectors. All this information is captured, filtered and piped to huge networks of microprocessors for analysis and study by an international team of physicists. When the Large Hadron Collider (LHC) comes on line in 2009, it will be the largest scientific experiment ever constructed, and the data it produces will lead to a new understanding of our Universe. Many thousands of scientists and engineers were behind the planning...

Literature in focus - The Large Hadron Collider: A Marvel of Technology

CERN Document Server

Cecile Noels

2009-01-01

Inside an insulating vacuum chamber in a tunnel about 100 metres below the surface of the Franco-Swiss plain near Geneva, packets of protons whirl around the 27-km circumference of the Large Hadron Collider (LHC) at a speed close to that of light, colliding every 25 nanoseconds at four beam crossing points. The products of these collisions, of which hundreds of billions will be produced each second, are observed and measured with the most advanced particle-detection technology, capable of tracking individual particles as they generate a signature track during their passage through the detectors. All this information is captured, filtered and piped to huge networks of microprocessors for analysis and study by an international team of physicists. When the Large Hadron Collider (LHC) comes on line in 2009, it will be the largest scientific experiment ever constructed, and the data it produces will lead to a new understanding of our Universe. Many thousands of scientists and engineers were behind the planning...

Destination Universe: The Incredible Journey of a Proton in the Large Hadron Collider (English version)

CERN Multimedia

Lefevre, C

2008-01-01

This brochure illustrates the incredible journey of a proton as he winds his way through the CERN accelerator chain and ends up inside the Large Hadron Collider (LHC). The LHC is CERN's flagship particle accelerator which can collide protons together at close to the speed of light, creating circumstances like those just seconds after the Big Bang.

Design of the large hadron electron collider interaction region

Directory of Open Access Journals (Sweden)

E. Cruz-Alaniz

2015-11-01

Full Text Available The large hadron electron collider (LHeC is a proposed upgrade of the Large Hadron Collider (LHC within the high luminosity LHC (HL-LHC project, to provide electron-nucleon collisions and explore a new regime of energy and luminosity for deep inelastic scattering. The design of an interaction region for any collider is always a challenging task given that the beams are brought into crossing with the smallest beam sizes in a region where there are tight detector constraints. In this case integrating the LHeC into the existing HL-LHC lattice, to allow simultaneous proton-proton and electron-proton collisions, increases the difficulty of the task. A nominal design was presented in the the LHeC conceptual design report in 2012 featuring an optical configuration that focuses one of the proton beams of the LHC to β^{*}=10  cm in the LHeC interaction point to reach the desired luminosity of L=10^{33}  cm^{-2} s^{-1}. This value is achieved with the aid of a new inner triplet of quadrupoles at a distance L^{*}=10  m from the interaction point. However the chromatic beta beating was found intolerable regarding machine protection issues. An advanced chromatic correction scheme was required. This paper explores the feasibility of the extension of a novel optical technique called the achromatic telescopic squeezing scheme and the flexibility of the interaction region design, in order to find the optimal solution that would produce the highest luminosity while controlling the chromaticity, minimizing the synchrotron radiation power and maintaining the dynamic aperture required for stability.

Charged Hadron Multiplicity Distribution at Relativistic Heavy-Ion Colliders

Directory of Open Access Journals (Sweden)

Ashwini Kumar

2013-01-01

Full Text Available The present paper reviews facts and problems concerning charge hadron production in high energy collisions. Main emphasis is laid on the qualitative and quantitative description of general characteristics and properties observed for charged hadrons produced in such high energy collisions. Various features of available experimental data, for example, the variations of charged hadron multiplicity and pseudorapidity density with the mass number of colliding nuclei, center-of-mass energies, and the collision centrality obtained from heavy-ion collider experiments, are interpreted in the context of various theoretical concepts and their implications. Finally, several important scaling features observed in the measurements mainly at RHIC and LHC experiments are highlighted in the view of these models to draw some insight regarding the particle production mechanism in heavy-ion collisions.

The Large Hadron Collider: Present Status and Prospects

CERN Document Server

Evans, Lyndon R

2000-01-01

The Large Hadron Collider (LHC), due to be commissioned in 2005, will provide particle physics with the first laboratory tool to access the energy frontier above 1 TeV. In order to achieve this , protons must be accelerated and stored at 7 TeV, colliding with an unprecedented luminosity of 1034 cm-2 s-1. The 8.3 Tesla guide field is obtained using conventional NbTi technology cooled to below the lambda point of helium. Considerable modification of the infrastructure around the existing LEP tunnel is needed to house the LHC machine and detectors. The project is advancing according to schedule with most of the major hardware systems including cryogenics and magnets under construction. A brief status report is given and future prospects are discussed.

The Large Hadron Collider Present Status and Prospects

CERN Document Server

Evans, Lyndon R

2001-01-01

The Large Hadron Collider (LHC), due to be commissioned in 2005, will provide particle physics with the first laboratory tool to access the energy frontier above 1 TeV. In order to achieve this , protons must be accelerated and stored at 7 TeV, colliding with an unprecedented luminosity of 1034 cm-2 s-1. The 8.3 Tesla guide field is obtained using conventional NbTi technology cooled to below the lambda point of helium. Considerable modification of the infrastructure around the existing LEP tunnel is needed to house the LHC machine and detectors. The project is advancing according to schedule with most of the major hardware systems including cryogenics and magnets under construction. A brief status report is given and future prospects are discussed.

2nd CERN-Fermilab Hadron Collider Physics Summer School, June 6-15, 2007, CERN

CERN Multimedia

2007-01-01

The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 9 MARCH 2007. The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, covered extensively the physics at the Tevatron collider experiments. The second school, to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be placed on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be supported by in-depth discussion sessions and will include the theory and phenomenology of hadron collisions, discovery physics topics, detector and analysis techniques and tools...

Supersymmetry phenomenology in the context of neutrino physics and the large hadron collider LHC

Energy Technology Data Exchange (ETDEWEB)

Hanussek, Marja

2012-05-15

Experimentally, it is well established that the Standard Model of particle physics requires an extension to accommodate the neutrino oscillation data, which indicates that at least two neutrinos are massive and that two of the neutrino mixing angles are large. Massive neutrinos are naturally present in a supersymmetric extension of the Standard Model which includes lepton-number violating terms (the B3 MSSM). Furthermore, supersymmetry stabilizes the hierarchy between the electroweak scale and the scale of unified theories or the Planck scale. In this thesis, we study in detail how neutrino masses are generated in the B3 MSSM. We present a mechanism how the experimental neutrino oscillation data can be realized in this framework. Then we discuss how recently published data from the Large Hadron Collider (LHC) can be used to constrain the parameter space of this model. Furthermore, we present work on supersymmetric models where R-parity is conserved, considering scenarios with light stops in the light of collider physics and scenarios with near-massless neutralinos in connection with cosmological restrictions.

Supersymmetry phenomenology in the context of neutrino physics and the large hadron collider LHC

International Nuclear Information System (INIS)

Hanussek, Marja

2012-05-01

Experimentally, it is well established that the Standard Model of particle physics requires an extension to accommodate the neutrino oscillation data, which indicates that at least two neutrinos are massive and that two of the neutrino mixing angles are large. Massive neutrinos are naturally present in a supersymmetric extension of the Standard Model which includes lepton-number violating terms (the B3 MSSM). Furthermore, supersymmetry stabilizes the hierarchy between the electroweak scale and the scale of unified theories or the Planck scale. In this thesis, we study in detail how neutrino masses are generated in the B3 MSSM. We present a mechanism how the experimental neutrino oscillation data can be realized in this framework. Then we discuss how recently published data from the Large Hadron Collider (LHC) can be used to constrain the parameter space of this model. Furthermore, we present work on supersymmetric models where R-parity is conserved, considering scenarios with light stops in the light of collider physics and scenarios with near-massless neutralinos in connection with cosmological restrictions.

The Large Hadron Collider, a personal recollection

CERN Document Server

Evans, L

2014-01-01

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

The Very Large Hadron Collider: The farthest energy frontier

International Nuclear Information System (INIS)

Barletta, William A.

2001-01-01

The Very Large Hadron Collider (or Eloisatron) represents what may well be the final step on the energy frontier of accelerator-based high energy physics. While an extremely high luminosity proton collider at 100-200 TeV center of mass energy can probably be built in one step with LHC technology, that machine would cost more than what is presently politically acceptable. This talk summarizes the strategies of collider design including staged deployment, comparison with electron-positron colliders, opportunities for major innovation, and the technical challenges of reducing costs to manageable proportions. It also presents the priorities for relevant R and D for the next few years

Luminosity Tuning at the Large Hadron Collider

CERN Document Server

Wittmer, W

2006-01-01

By measuring and adjusting the beta-functions at the interaction point (IP the luminosity is being optimized. In LEP (Large Electron Positron Collider) this was done with the two closest doublet magnets. This approach is not applicable for the LHC (Large Hadron Collider) and RHIC (Relativistic Heavy Ion Collider) due to the asymmetric lattice. In addition in the LHC both beams share a common beam pipe through the inner triplet magnets (in these region changes of the magnetic field act on both beams). To control and adjust the beta-functions without perturbation of other optics functions, quadrupole groups situated on both sides further away from the IP have to be used where the two beams are already separated. The quadrupoles are excited in specific linear combinations, forming the so-called "tuning knobs" for the IP beta-functions. For a specific correction one of these knobs is scaled by a common multiplier. The different methods which were used to compute such knobs are discussed: (1) matching in MAD, (2)i...

arXiv Proceedings of the Sixth International Workshop on Multiple Partonic Interactions at the Large Hadron Collider

CERN Document Server

Astalos, R.; Bartalini, P.; Belyaev, I.; Bierlich, Ch.; Blok, B.; Buckley, A.; Ceccopieri, F.A.; Cherednikov, I.; Christiansen, J.R.; Ciangottini, D.; Deak, M.; Ducloue, B.; Field, R.; Gaunt, J.R.; Golec-Biernat, K.; Goerlich, L.; Grebenyuk, A.; Gueta, O.; Gunnellini, P.; Helenius, I.; Jung, H.; Kar, D.; Kepka, O.; Klusek-Gawenda, M.; Knutsson, A.; Kotko, P.; Krasny, M.W.; Kutak, K.; Lewandowska, E.; Lykasov, G.; Maciula, R.; Moraes, A.M.; Martin, T.; Mitsuka, G.; Motyka, L.; Myska, M.; Otwinowski, J.; Pierog, T.; Pleskot, V.; Rinaldi, M.; Schafer, W.; Siodmok, A.; Sjostrand, T.; Snigirev, A.; Stasto, A.; Staszewski, R.; Stebel, T.; Strikman, M.; Szczurek, A.; Treleani, D.; Trzebinski, M.; van Haevermaet, H.; van Hameren, A.; van Mechelen, P.; Waalewijn, W.; Wang, W.Y.; MPI@LHC 2014

2014-01-01

Multiple Partonic Interactions are often crucial for interpreting results obtained at the Large Hadron Collider (LHC). The quest for a sound understanding of the dynamics behind MPI - particularly at this time when the LHC is due to start its "Run II" operations - has focused the aim of this workshop. MPI@LHC2014 concentrated mainly on the phenomenology of LHC measurements whilst keeping in perspective those results obtained at previous hadron colliders. The workshop has also debated some of the state-of-the-art theoretical considerations and the modeling of MPI in Monte Carlo event generators. The topics debated in the workshop included: Phenomenology of MPI processes and multiparton distributions; Considerations for the description of MPI in Quantum Chromodynamics (QCD); Measuring multiple partonic interactions; Experimental results on inelastic hadronic collisions: underlying event, minimum bias, forward energy flow; Monte Carlo generator development and tuning; Connections with low-x phenomena, diffractio...

Cryogenics for the Large Hadron Collider

CERN Document Server

Lebrun, P

2000-01-01

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

Status of the 16 T dipole development program for a future hadron collider

NARCIS (Netherlands)

Tommasini, Davide; Arbelaez, Diego; Auchmann, Bernhard; Bajas, Hugues; Bajko, Marta; Ballarino, Amalia; Barzi, Emanuela; Bellomo, Giovanni; Benedikt, Michael; Izquierdo Bermudez, Susana; Bordini, Bernardo; Bottura, Luca; Brouwer, Lucas; Buzio, Marco; Caiffi, Barbara; Caspi, Shlomo; Dhalle, Marc; Durante, Maria; De Rijk, Gijs; Fabbricatore, Pasquale; Farinon, Stefania; Ferracin, Paolo; Gao, Peng; Gourlay, Steve; Juchno, Mariusz; Kashikhin, Vadim; Lackner, Friedrich; Lorin, Clement; Marchevsky, Maxim; Marinozzi, Vittorio; Martinez, Teresa; Munilla, Javier; Novitski, Igor; Ogitsu, Toru; Ortwein, Rafal; Perez, Juan Carlos; Petrone, Carlo; Prestemon, Soren; Prioli, Marco; Rifflet, Jean Michel; Rochepault, Etienne; Russenschuck, Stephan; Salmi, Tiina; Savary, Frederic; Schoerling, Daniel; Segreti, Michel; Senatore, Carmine; Sorbi, Massimo; Stenvall, Antti; Todesco, Ezio; Toral, Fernando; Verweij, Arjan P.; Wessel, W.A.J.; Wolf, Felix; Zlobin, Alexander

A next step of energy increase of hadron colliders beyond the LHC requires high-field superconducting magnets capable of providing a dipolar field in the range of 16 T in a 50 mm aperture with accelerator quality. These characteristics could meet the re-quirements for an upgrade of the LHC to twice

Accelerator physics and technology challenges of very high energy hadron colliders

Science.gov (United States)

Shiltsev, Vladimir D.

2015-08-01

High energy hadron colliders have been in the forefront of particle physics for more than three decades. At present, international particle physics community considers several options for a 100 TeV proton-proton collider as a possible post-LHC energy frontier facility. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. This paper briefly reviews the accelerator physics and technology challenges of the future very high energy colliders and outlines the areas of required research and development towards their technical and financial feasibility.

Higgs-photon associated production at hadron colliders

International Nuclear Information System (INIS)

Abbasabadi, A.; Repko, W.W.

1997-01-01

The authors present cross sections for the reactions p anti p → Hγ and pp → Hγ arising from the subprocess q anti q → Hγ. The calculation includes the complete one-loop contribution from all light quarks and is the main source of Higgs-photon associated production in hadron colliders. At Tevatron energies, the cross section is typically 0.1 fb or less, while at LHC energies it can exceed 1.0fb

The Initial Stages of Colliding Nuclei and Hadrons

International Nuclear Information System (INIS)

Tribedy, Prithwish

2017-01-01

The final day of the Hot Quarks 2016 conference was focused on the discussions of the initial stages of colliding nuclei and hadrons. In this conference proceedings we give a brief overview of a few selective topics discussed at the conference that include latest developments in the theoretical description of the initial state towards understanding a number of recent experimental results from RHIC and LHC. (paper)

Search for invisibly decaying Higgs boson at Large Hadron Collider

Indian Academy of Sciences (India)

In several scenarios of Beyond Standard Model physics, the invisible decay mode of the Higgs boson is an interesting possibility. The search strategy for an invisible Higgs boson at the Large Hadron Collider (LHC), using weak boson fusion process, has been studied in detail, by taking into account all possible ...

Higgs Boson Searches at Hadron Colliders (1/4)

CERN Multimedia

CERN. Geneva

2010-01-01

In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and strategies to measured Higgs boson parameters and the investigation of alternative symmetry breaking scenarios are addressed.

Physics at a future collider beyond the LHC and a TeV class linear collider

CERN Multimedia

CERN. Geneva

2003-01-01

After the LHC will have probed the physics at the TeV frontier, new generations of colliders capable of reaching into the multi-TeV energy domain will need to be considered. Concepts for both high energy e+e- linear colliders and muon storage rings have been proposed as well as hadron colliders. Highly challenging R&D programs are presently pursued to demonstrate their principles. The definition of a physics programme in the multi-TeV range still requires essential data that is likely to become available only after the first years of LHC operation and, possibly, also the results from a TeV-class linear collider. At present we have to envisage several possible scenarios for the fundamental questions to be addressed by collider experiments in the next decade, to guide the choices in the accelerator designs and parameters. After a brief review of the main accelerator projects and the present status of their R&D, I shall discuss the main signatures of the physics of possible relevance in relation to the e...

Supersymmetric dark matter in the harsh light of the Large Hadron Collider

Science.gov (United States)

Peskin, Michael E.

2015-01-01

I review the status of the model of dark matter as the neutralino of supersymmetry in the light of constraints on supersymmetry given by the 7- to 8-TeV data from the Large Hadron Collider (LHC). PMID:25331902

Theory Overview of Electroweak Physics at Hadron Colliders

Energy Technology Data Exchange (ETDEWEB)

Campbell, John M. [Fermilab

2016-09-03

This contribution summarizes some of the important theoretical progress that has been made in the arena of electroweak physics at hadron colliders. The focus is on developments that have sharpened theoretical predictions for final states produced through electroweak processes. Special attention is paid to new results that have been presented in the last year, since LHCP2015, as well as on key issues for future measurements at the LHC.

Design Study for a Staged Very Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Chao, Alex W.

2002-02-27

Particle physics makes its greatest advances with experiments at the highest energy. The only sure way to advance to a higher-energy regime is through hadron colliders--the Tevatron, the LHC, and then, beyond that, a Very Large Hadron Collider. At Snowmass-1996 [1], investigators explored the best way to build a VLHC, which they defined as a 100 TeV collider. The goals in this study are different. The current study seeks to identify the best and cheapest way to arrive at frontier-energy physics, while simultaneously starting down a path that will eventually lead to the highest-energy collisions technologically possible in any accelerator using presently conceivable technology. This study takes the first steps toward understanding the accelerator physics issues, the technological possibilities and the approximate cost of a particular model of the VLHC. It describes a staged approach that offers exciting physics at each stage for the least cost, and finally reaches an energy one-hundred times the highest energy currently achievable.

QCD threshold corrections for gluino pair production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Langenfeld, Ulrich [Wuerzburg Univ. (Germany); Moch, Sven-Olaf; Pfoh, Torsten [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2012-11-15

We present the complete threshold enhanced predictions in QCD for the total cross section of gluino pair production at hadron colliders at next-to-next-to-leading order. Thanks to the computation of the required one-loop hard matching coefficients our results are accurate to the next-to-next-to-leading logarithm. In a brief phenomenological study we provide predictions for the total hadronic cross sections at the LHC and we discuss the uncertainties arising from scale variations and the parton distribution functions.

Cooldown and Warmup Studies for the Large Hadron Collider

CERN Document Server

Lebrun, P; Tavian, L; Wagner, U

1998-01-01

The Large Hadron Collider (LHC), currently under construction at CERN, will make use of superconducting magnets operating in superfluid helium below 2 K. The LHC ring is divided in 8 sectors, each of them cooled by a refrigerator of 18 kW at 4.5 K equivalent cooling power. For the cooldown and warmup of a 3.3 km long LHC sector, the flow available above 80 K per refrigerator is 770 g/s and the cor responding capacity is 600 kW. This paper presents the results of cooldown and warmup simulations, as concerns time delays, temperature difference across magnets, available power and flow-rates, and estimates of energy and liquid nitrogen consumption.

Supersymmetric Higgs pair discovery prospects at hadron colliders

CERN Document Server

Belyaev, A; Éboli, Oscar J P; Mizukoshi, J K; Novaes, S F

2000-01-01

We study the potential of hadron colliders in the search for the pair production of neutral Higgs bosons in the framework of the Minimal Supersymmetric Standard Model. Using analytical expressions for the relevant amplitudes, we perform a detailed signal and background analysis, working out efficient kinematical cuts for the extraction of the signal. The important role of squark loop contributions to the signal is emphasised. If the signal is sufficiently enhanced by these contributions, it could even be observable at the next run of the upgraded Tevatron collider in the near future. At the LHC the pair production of light and heavy Higgs bosons might be detectable simultaneously.

Heavy-Ion Collimation at the Large Hadron Collider: Simulations and Measurements

OpenAIRE

Hermes, Pascal Dominik; Wessels, Johannes Peter; Bruce, Roderik; Wessels, Johannes Peter; Bruce, Roderik

2017-01-01

The CERN Large Hadron Collider (LHC) stores and collides proton and $^{208}$Pb$^{82+}$ beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets ca...

Heavy-Ion Collimation at the Large Hadron Collider Simulations and Measurements

CERN Document Server

AUTHOR|(CDS)2083002; Wessels, Johannes Peter; Bruce, Roderik; Wessels, Johannes Peter; Bruce, Roderik

The CERN Large Hadron Collider (LHC) stores and collides proton and $^{208}$Pb$^{82+}$ beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets can still scatter out of the collimation system. When they irradiate the superconducting LHC magnets, the latter risk to quench (lose their superconducting property). These secondary collimation losses can potentially impose a limitation for the stored heavy-ion beam energy. Therefore, their distribution in the LHC needs to be understood by sophisticated simulations. Such simulation tools must accurately simulate the particle motion of many different nuclides in the magnetic LHC lattice and simulate their interaction with t...

Preliminary design of the beam screen cooling for the Future Circular Collider of hadron beams

CERN Document Server

Kotnig, C

2015-01-01

Following recommendations of the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. This study considers an option for a very high energy (100 TeV) hadron-hadron collider located in a quasi-circular underground tunnel having a circumference of 80 to 100 km. The synchrotron radiation emitted by the high-energy hadron beam increases by more than two orders of magnitude compared to the LHC. To reduce the entropic load on the superconducting magnets' refrigeration system, beam screens are indispensable to extract the heat load at a higher temperature level. After illustrating the decisive constraints of the beam screen's refrigeration design, this paper presents a preliminary design of the length of a continuous cooling loop comparing helium and neon, for different cooling channel geometries with emphasis on the cooling length limitations and the exergetic efficiency.

Preliminary design of the beam screen cooling for the Future Circular Collider of hadron beams

Science.gov (United States)

Kotnig, C.; Tavian, L.

2015-12-01

Following recommendations of the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. This study considers an option for a very high energy (100 TeV) hadron-hadron collider located in a quasi-circular underground tunnel having a circumference of 80 to 100 km. The synchrotron radiation emitted by the high-energy hadron beam increases by more than two orders of magnitude compared to the LHC. To reduce the entropic load on the superconducting magnets’ refrigeration system, beam screens are indispensable to extract the heat load at a higher temperature level. After illustrating the decisive constraints of the beam screen's refrigeration design, this paper presents a preliminary design of the length of a continuous cooling loop comparing helium and neon, for different cooling channel geometries with emphasis on the cooling length limitations and the exergetic efficiency.

Upgrade of the ATLAS hadronic Tile calorimeter for the High luminosity LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00236332; The ATLAS collaboration

2016-01-01

The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It is a sampling calorimeter consisting of alternating thin steel plates and scintillating tiles. Wavelength shifting fibers coupled to the tiles collect the produced light and are read out by photomultiplier tubes. An analog sum of the processed signal of several photomultipliers serves as input to the first level of trigger. Photomultiplier signals are then digitized and stored on detector and are only transferred off detector once the first trigger acceptance has been confirmed. The Large Hadron Collider (LHC) has envisaged a series of upgrades towards a High Luminosity LHC (HL-LHC) delivering five times the LHC nominal instantaneous luminosity. The ATLAS Phase II upgrade, in 2024, will accommodate the detector and data acquisition system for the HL-LHC. In particular, TileCal will undergo a major replacement of its on- and off-detector electronics. All signals will be digitized and then...

Upgrade of the ATLAS hadronic Tile calorimeter for the High luminosity LHC

CERN Document Server

Mlynarikova, Michaela; The ATLAS collaboration

2017-01-01

The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It is a sampling calorimeter consisting of alternating thin steel plates and scintillating tiles. Wavelength shifting fibers coupled to the tiles collect the produced light and are read out by photomultiplier tubes. Currently, an analog sum of the processed signal of several photomultipliers serves as input to the first level of trigger. Photomultiplier signals are then digitized and stored on detector and are only transferred off detector once the first trigger acceptance has been confirmed. The Large Hadron Collider (LHC) has envisaged a series of upgrades towards a High Luminosity LHC (HL-LHC) delivering five times the LHC nominal instantaneous luminosity. The ATLAS Phase II upgrade, in 2024, will accommodate the detector and data acquisition system for the HL-LHC. In particular, TileCal will undergo a major replacement of its on- and off-detector electronics. All signals will be digitiz...

Hadron collider physics at UCR

International Nuclear Information System (INIS)

Kernan, A.; Shen, B.C.

1997-01-01

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

Secondary particle in background levels and effects on detectors at future hadron colliders

International Nuclear Information System (INIS)

Pal, T.

1993-06-01

The next generation of hadron colliders, the Superconducting Super Collider (SSC) and the Large Hadron Collider (LHC), will operate at high center-of-mass energies and luminosities. Namely, for the SSC (LHC) √s = 40 TeV (√s = 16 TeV) and L = 10 33 cm -2 s -1 (L = 3 x 10 34 cm -2 s -1 ). These conditions will result in the production of large backgrounds as well as radiation environments. Ascertaining the backgrounds, in terms of the production of secondary charged and neutral particles, and the radiation environments are important considerations for the detectors proposed for these colliders. An initial investigation of the radiation levels in the SSC detectors was undertaken by D. Groom and colleagues, in the context of the ''task force on radiation levels in the SSC interaction regions.'' The method consisted essentially of an analytic approach, using standard descriptions of average events in conjunction with simulations of secondary processes. Following Groom's work, extensive Monte Carlo simulations were performed to address the issues of backgrounds and radiation environments for the GEM and SD C3 experiments proposed at the SSC, and for the ATLAS and CMS experiments planned for the LHC. The purpose of the present article is to give a brief summary of some aspects of the methods, assumptions, and calculations performed to date (principally for the SSC detectors), and to stress the relevance of such calculations to the detectors proposed for the study of B-physics in particular

Hadron collider physics at UCR

Energy Technology Data Exchange (ETDEWEB)

Kernan, A.; Shen, B.C.

1997-07-01

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

Towards future circular colliders

Science.gov (United States)

Benedikt, Michael; Zimmermann, Frank

2016-09-01

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

Conceptual design of hollow electron lenses for beam halo control in the Large Hadron Collider

CERN Document Server

Stancari, Giulio; Valishev, Alexander; Bruce, Roderik; Redaelli, Stefano; Rossi, Adriana; Salvachua Ferrando, Belen

2014-01-01

Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. Within the US LHC Accelerator Research Program (LARP) and the European FP7 HiLumi LHC Design Study, we are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were check...

Towards Future Circular Colliders

CERN Document Server

AUTHOR|(CDS)2108454; Zimmermann, Frank

2016-01-01

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

Protection of the CERN Large Hadron Collider

Science.gov (United States)

Schmidt, R.; Assmann, R.; Carlier, E.; Dehning, B.; Denz, R.; Goddard, B.; Holzer, E. B.; Kain, V.; Puccio, B.; Todd, B.; Uythoven, J.; Wenninger, J.; Zerlauth, M.

2006-11-01

The Large Hadron Collider (LHC) at CERN will collide two counter-rotating proton beams, each with an energy of 7 TeV. The energy stored in the superconducting magnet system will exceed 10 GJ, and each beam has a stored energy of 362 MJ which could cause major damage to accelerator equipment in the case of uncontrolled beam loss. Safe operation of the LHC will therefore rely on a complex system for equipment protection. The systems for protection of the superconducting magnets in case of quench must be fully operational before powering the magnets. For safe injection of the 450 GeV beam into the LHC, beam absorbers must be in their correct positions and specific procedures must be applied. Requirements for safe operation throughout the cycle necessitate early detection of failures within the equipment, and active monitoring of the beam with fast and reliable beam instrumentation, mainly beam loss monitors (BLM). When operating with circulating beams, the time constant for beam loss after a failure extends from apms to a few minutes—failures must be detected sufficiently early and transmitted to the beam interlock system that triggers a beam dump. It is essential that the beams are properly extracted on to the dump blocks at the end of a fill and in case of emergency, since the beam dump blocks are the only elements of the LHC that can withstand the impact of the full beam.

The Large Hadron Collider: lessons learned and summary

CERN Document Server

Llewellyn Smith, Chris

2012-01-01

The Large Hadron Collider (LHC) machine and detectors are now working superbly. There are good reasons to hope and expect that the new domain that the LHC is already exploring, operating at 7 TeV with a luminosity of 1033 cm−2 s−1, or the much bigger domain that will be opened up as the luminosity increases to over 1034 and the energy to 14 TeV, will provide clues that will usher in a new era in particle physics. The arguments that new phenomena will be found in the energy range that will be explored by the LHC have become stronger since they were first seriously analysed in 1984, although their essence has changed little. I will review the evolution of these arguments in a historical context, the development of the LHC project since 1984, and the outlook in the light of reports on the performance of the machine and detectors presented at this meeting.

Dosimetric And Fluence Measurements At Hadron Facilities For LHC Radiation Damage Studies

CERN Document Server

León-Florián, E

2001-01-01

Dosimetry plays an essential role in experiments assessing radiation damage and hardness for the components of detectors to be operated at the future Large Hadron Collider (LHC), CERN (European Laboratory for Particle Physics), Geneva, Switzerland. Dosimetry is used both for calibration of the radiation fields and estimate of fluences and doses during the irradiation tests. The LHC environment will result in a complex radiation field composed of hadrons (mainly neutrons, pions and protons) and photons, each having an energy spectrum ranging from a few keV to several hundreds of MeV or several GeV, even. In this thesis, are exposed the results of measurements of particle fluences and doses at different hadron irradiation facilities: SARA, πE1-PSI and ZT7PS used for testing the radiation hardness of materials and equipment to be used in the future experiments at LHC. These measurements are applied to the evaluation of radiation damage inflicted to various semiconductors (such as silicon) and electronics ...

Heavy-ion performance of the LHC and future colliders

CERN Document Server

AUTHOR|(SzGeCERN)696614; Stahl, Achim; Jowett, John M

2015-10-09

In 2008 the Large Hadron Collider (LHC) and its experiments started operation at the European Centre of Nuclear Research (CERN) in Geneva with the main aim of finding or excluding the Higgs boson. Only four years later, on the 4th of July 2012, the discovery of a Higgs-like particle was proven and first published by the two main experiments ATLAS and CMS. Even though proton–proton collisions are the main operation mode of the LHC, it also acts as an heavy-ion collider. Here, the term “heavy-ion collisions” refers to the collision between fully stripped nuclei. While the major hardware system of the LHC is compatible with heavy-ion operation, the beam dynamics and performance limits of ion beams are quite different from those of protons. Because of the higher mass and charge of the ions, beam dynamic effects like intra-beam scattering and radiation damping are stronger. Also the electromagnetic cross-sections in the collisions are larger, leading to significantly faster intensity decay and thus shorter l...

Unveiling the top secrets with the Large Hadron Collider

Science.gov (United States)

Chierici, R.

2013-12-01

Top quark physics is one of the pillars of fundamental research in the field of high energy physics. It not only gives access to precision measurements for constraining the Standard Model of particles and interactions but also it represents a privileged domain for new physics searches. This contribution summarizes the main results in top quark physics obtained with the two general-purpose detectors ATLAS and CMS during the first two years of operations of the Large Hadron Collider (LHC) at CERN. It covers the 2010 and 2011 data taking periods, where the LHC ran at a centre-of-mass energy of 7 TeV.

Unveiling the top secrets with the Large Hadron Collider

International Nuclear Information System (INIS)

Chierici, R

2013-01-01

Top quark physics is one of the pillars of fundamental research in the field of high energy physics. It not only gives access to precision measurements for constraining the Standard Model of particles and interactions but also it represents a privileged domain for new physics searches. This contribution summarizes the main results in top quark physics obtained with the two general-purpose detectors ATLAS and CMS during the first two years of operations of the Large Hadron Collider (LHC) at CERN. It covers the 2010 and 2011 data taking periods, where the LHC ran at a centre-of-mass energy of 7 TeV. (paper)

Recent results from the Large Hadron Collider

CERN Document Server

Alcaraz Maestre, J

2013-01-01

We present an overview of the physics results obtained by experiments at the Large Hadron Collider (LHC) in 2009–2010, for an integrated luminosity of L ≈ 40 pb$^{−1}$ , collected mostly at a centre-of-mass energy of √ s = 7 TeV. After an introduction to the physics environment at the LHC and the current performance of the accelerator and detectors, we will discuss quantum chro- modynamics and B-physics analyses, W and Z production, the first results in the top sector, and searches for new physics, with particular emphasis on su- persymmetry and Higgs studies. While most of the presented results are in remarkable agreement with Standard Model predictions, the excellent perfor- mance of the LHC machine and experiments, the prompt analysis of all data within just a few months after the end of data taking, and the high quality of the results obtained constitute an encouraging step towards unique measurements and exciting discoveries in the 2011–2012 period and beyond.

Hunting electroweakinos at future hadron colliders and direct detection experiments

Energy Technology Data Exchange (ETDEWEB)

Cortona, Giovanni Grilli di [SISSA - International School for Advanced Studies,Via Bonomea 265, I-34136 Trieste (Italy); INFN - Sezione di Trieste,via Valerio 2, I-34127 Trieste (Italy)

2015-05-07

We analyse the mass reach for electroweakinos at future hadron colliders and their interplay with direct detection experiments. Motivated by the LHC data, we focus on split supersymmetry models with different electroweakino spectra. We find for example that a 100 TeV collider may explore Winos up to ∼7 TeV in low scale gauge mediation models or thermal Wino dark matter around 3 TeV in models of anomaly mediation with long-lived Winos. We show moreover how collider searches and direct detection experiments have the potential to cover large part of the parameter space even in scenarios where the lightest neutralino does not contribute to the whole dark matter relic density.

Large hadron collider in the LEP tunnel. Proceedings. Vol. 2

International Nuclear Information System (INIS)

1984-01-01

A Workshop, jointly organized by ECFA and CERN, took place at Lausanne and at CERN in March 1984 to study various options for a pp (or panti p) collider which might be installed at a later data alongside LEP in the LEP tunnel. Following the exploration of e + e - physics up to the highest energy now foreseeable, this would open up the opportunity to investigate hadron collisions in the new energy range of 10 to 20 TeV in the centre of mass. These proceedings put together the documents prepared in connection with this Workshop. They cover possible options for a Large Hadron Collider (LHC) in the LEP tunnel, the physics case as it stands at present, and studies of experimental possibilities in this energy range with luminosities as now considered. See hints under the relevant topics. (orig./HSI)

Large hadron collider in the LEP tunnel. Proceedings. Vol. 1

International Nuclear Information System (INIS)

1984-01-01

A Workshop, jointly organized by ECFA and CERN, took place at Lausanne and at CERN in March 1984 to study various options for a pp (or panti p) collider which might be installed at a later date alongside LEP in the LEP tunnel. Following the exploration of e + e - physics up to the highest energy now foreseeable, this would open up the opportunity to investigate hadron collisions in the new energy range of 10 to 20 TeV in the centre of mass. These proceedings put together the documents prepared in connection with this Workshop. They cover possible options for a Large Hadron Collider (LHC= in the LEP tunnel, the physics case at it stands at present, and studies of experimental possibilities in this energy range with luminosities as now considered. See hints under the relevant topics. (orig.)

Photoproduction at collider energies: from RHIC and HERA to the LHC

CERN Document Server

Baltz, A; Brodsky, S J; D'Enterria, D G; Dreyer, U; Engel, R; Frankfurt, L; Gorbunov, Y; Guzey, V; Hamilton, A; Klasen, M; Klein, S R; Kowalski, H; Levonian, S; Lourenço, C; Machado, M V T; Nachtmann, O; Nagy, Z; Nystrand, J; Piotrzkowski, K; Ramalhete, P; Savin, A; Scapparone, E; Schicker, R; Silvermyr, D; Strikman, M I; Valkárová, A; Vogt, R; Yilmaz, M; Enterria, David d'

2007-01-01

We present the mini-proceedings of the workshop on "Photoproduction at collider energies: from RHIC and HERA to the LHC" held at the European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*, Trento) from January 15 to 19, 2007. The workshop gathered both theorists and experimentalists to discuss the current status of investigations of high-energy photon-induced processes at different colliders (HERA, RHIC, and Tevatron) as well as preparations for extension of these studies at the LHC. The main physics topics covered were: (i) small-$x$ QCD in photoproduction studies with protons and in electromagnetic (aka. ultraperipheral) nucleus-nucleus collisions, (ii) hard diffraction physics at hadron colliders, and (iii) photon-photon collisions at very high energies: electroweak and beyond the Standard Model processes. These mini-proceedings consist of an introduction and short summaries of the talks presented at the meeting.

Heavy-ion performance of the LHC and future colliders

Energy Technology Data Exchange (ETDEWEB)

Schaumann, Michaela

2015-04-29

In 2008 the Large Hadron Collider (LHC) and its experiments started operation at the European Centre of Nuclear Research (CERN) in Geneva with the main aim of finding or excluding the Higgs boson. Only four years later, on the 4th of July 2012, the discovery of a Higgs-like particle was proven and first published by the two main experiments ATLAS and CMS. Even though proton-proton collisions are the main operation mode of the LHC, it also acts as an heavy-ion collider. Here, the term ''heavy-ion collisions'' refers to the collision between fully stripped nuclei. While the major hardware system of the LHC is compatible with heavy-ion operation, the beam dynamics and performance limits of ion beams are quite different from those of protons. Because of the higher mass and charge of the ions, beam dynamic effects like intra-beam scattering and radiation damping are stronger. Also the electromagnetic cross-sections in the collisions are larger, leading to significantly faster intensity decay and thus shorter luminosity lifetimes. As the production cross-sections for various physics processes under study of the experiments are still small at energies reachable with the LHC and because the heavy-ion run time is limited to a few days per year, it is essential to obtain the highest possible collision rate, i.e. maximise the instantaneous luminosity, in order to obtain enough events and therefore low statistical errors. Within this thesis, the past performance of the LHC in lead-lead (Pb-Pb) collisions, at a centre-of-mass energy of 2.76 TeV per colliding nucleon pair, is analysed and potential luminosity limitations are identified. Tools are developed to predict future performance and techniques are presented to further increase the luminosity. Finally, a perspective on the future of high energy heavy-ion colliders is given.

An investigation of triply heavy baryon production at hadron colliders

CERN Document Server

Gomshi Nobary, M A

2006-01-01

The triply heavy baryons have a rather diverse mass range. While some of them possess considerable production rates at existing facilities, others need to be produced at future high energy colliders. Here we study the direct fragmentation production of the Ωccc and Ωbbb baryons as the prototypes of triply heavy baryons at the hadron colliders with different . We present and compare the transverse momentum distributions of the differential cross sections, distributions of total cross sections and the integrated total cross sections of these states at the RHIC, the Tevatron Run II and the CERN LHC.

VUV photoemission studies of candidate Large Hadron Collider vacuum chamber materials

CERN Document Server

Cimino, R; Baglin, V

1999-01-01

In the context of future accelerators and, in particular, the beam vacuum of the Large Hadron Collider (LHC), a 27 km circumference proton collider to be built at CERN, VUV synchrotron radiation (SR) has been used to study both qualitatively and quantitatively candidate vacuum chamber materials. Emphasis is given to show that angle and energy resolved photoemission is an extremely powerful tool to address important issues relevant to the LHC, such as the emission of electrons that contributes to the creation of an electron cloud which may cause serious beam instabilities and unmanageable heat loads on the cryogenic system. Here we present not only the measured photoelectron yields from the proposed materials, prepared on an industrial scale, but also the energy and in some cases the angular dependence of the emitted electrons when excited with either a white light (WL) spectrum, simulating that in the arcs of the LHC, or monochromatic light in the photon energy range of interest. The effects on the materials ...

Test of Relativistic Gravity for Propulsion at the Large Hadron Collider

Science.gov (United States)

Felber, Franklin

2010-01-01

A design is presented of a laboratory experiment that could test the suitability of relativistic gravity for propulsion of spacecraft to relativistic speeds. An exact time-dependent solution of Einstein's gravitational field equation confirms that even the weak field of a mass moving at relativistic speeds could serve as a driver to accelerate a much lighter payload from rest to a good fraction of the speed of light. The time-dependent field of ultrarelativistic particles in a collider ring is calculated. An experiment is proposed as the first test of the predictions of general relativity in the ultrarelativistic limit by measuring the repulsive gravitational field of bunches of protons in the Large Hadron Collider (LHC). The estimated `antigravity beam' signal strength at a resonant detector of each proton bunch is 3 nm/s2 for 2 ns during each revolution of the LHC. This experiment can be performed off-line, without interfering with the normal operations of the LHC.

Upgrade of the ATLAS hadronic Tile calorimeter for the High luminosity LHC

CERN Document Server

Asensi Tortajada, Ignacio; The ATLAS collaboration

2017-01-01

The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It is a sampling calorimeter consisting of alternating thin steel plates and scintillating tiles. Wavelength shifting fibers coupled to the tiles collect the produced light and are read out by photomultiplier tubes. An analog sum of the processed signal of several photomultipliers serves as input to the first level of trigger. Photomultiplier signals are then digitized at 40 MHz and stored on detector and are only transferred off detector once the first level trigger acceptance has been confirmed (at a rate of maximum 100 kHz). The Large Hadron Collider (LHC) has envisaged a series of upgrades towards a High Luminosity LHC (HL-LHC) delivering five times the LHC nominal instantaneous luminosity. The ATLAS Phase II upgrade, in 2024, will accommodate the upgrade of the detector and data acquisition system for the HL-LHC. In particular, TileCal will undergo a major replacement of its on- and of...

CERN celebrating the Lowering of the final detector element for large Hadron Collider

CERN Multimedia

2008-01-01

In the early hours of the morning the final element of the Compact Muon Solenoid (CMS) detector began the descent into its underground experimental cavern in preparation for the start-up of CERNs Large Hadron Collider (LHC) this summer. This is a pivotal moment for the CMS collaboration.

Probing gauge-phobic heavy Higgs bosons at high energy hadron colliders

Directory of Open Access Journals (Sweden)

Yu-Ping Kuang

2015-07-01

Full Text Available We study the probe of the gauge-phobic (or nearly gauge-phobic heavy Higgs bosons (GPHB at high energy hadron colliders including the 14 TeV LHC and the 50 TeV Super Proton–Proton Collider (SppC. We take the process pp→tt¯tt¯, and study it at the hadron level including simulating the jet formation and top quark tagging (with jet substructure. We show that, for a GPHB with MH<800 GeV, MH can be determined by adjusting the value of MH in the theoretical pT(b1 distribution to fit the observed pT(b1 distribution, and the resonance peak can be seen at the SppC for MH=800 GeV and 1 TeV.

Large hadron collider workshop. Proceedings. Vol. 1

International Nuclear Information System (INIS)

Jarlskog, G.; Rein, D.

1990-01-01

The aim of the LCH workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

NARCIS (Netherlands)

Aad, G.; et al., [Unknown; Bentvelsen, S.; Berglund, E.; Bobbink, G.J.; Bos, K.; Boterenbrood, H.; Colijn, A.P.; de Jong, P.; de Nooij, L.; Deviveiros, P.O.; Doxiadis, A.D.; Ferrari, P.; Garitaonandia, H.; Geerts, D.A.A.; Gosselink, M.; Hartjes, F.; Hessey, N.P.; Igonkina, O.; Kayl, M.S.; Klous, S.; Kluit, P.; Koffeman, E.; Lee, H.; Lenz, T.; Linde, F.; Luijckx, G.; Massaro, G.; Mechnich, J.; Mussche, I.; Ottersbach, J.P.; Reichold, A.; Rijpstra, M.; Ruckstuhl, N.; Snuverink, J.; Ta, D.; Tsiakiris, M.; Turlay, E.; van der Graaf, H.; van der Kraaij, E.; van der Leeuw, R.; van der Poel, E.; van Kesteren, Z.; van Vulpen, I.; Verkerke, W.; Vermeulen, J.C.; Vranjes Milosavljevic, M.; Vreeswijk, M.

2013-01-01

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at

Availability modeling approach for future circular colliders based on the LHC operation experience

CERN Document Server

AUTHOR|(CDS)2096726; Apollonio, Andrea; Gutleber, Johannes; Sollander, Peter; Penttinen, Jussi-Pekka; Virtanen, Seppo Johannes

2016-01-01

Reaching the challenging integrated luminosity production goals of a future circular hadron collider (FCC-hh) and high luminosity LHC (HL-LHC) requires a thorough understanding of today’s most powerful high energy physics research infrastructure, the LHC accelerator complex at CERN. FCC-hh, a 4 times larger collider ring aims at delivering 10–20  ab$^-$$^1$ of integrated luminosity at 7 times higher collision energy. Since the identification of the key factors that impact availability and cost is far from obvious, a dedicated activity has been launched in the frame of the future circular collider study to develop models to study possible ways to optimize accelerator availability. This paper introduces the FCC reliability and availability study, which takes a fresh new look at assessing and modeling reliability and availability of particle accelerator infrastructures. The paper presents a probabilistic approach for Monte Carlo simulation of the machine operational cycle, schedule and availability for p...

The Large Hadron Collider

CERN Multimedia

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

2007-01-01

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

Inside CERN's Large Hadron Collider from the proton to the Higgs boson

CERN Document Server

AUTHOR|(CDS)2051256

2016-01-01

The book aims to explain the historical development of particle physics, with special emphasis on CERN and collider physics. It describes in detail the LHC accelerator and its detectors, describing the science involved as well as the sociology of big collaborations, culminating with the discovery of the Higgs boson. Readers are led step-by-step to understanding why we do particle physics, as well as the tools and problems involved in the field. It provides an insider's view on the experiments at the Large Hadron Collider.

Science and the Large Hadron Collider: a probe into instrumentation, periodization and classification

CERN Document Server

Roy, Arpita

2012-01-01

On September 19, 2008, the Large Hadron Collider (LHC) at CERN, Switzerland, began the world’s highest energy experiments as a probe into the structure of matter and forces of nature. Just nine days after the gala start-up, an explosion occurred in the LHC tunnel that brought the epic collider to a complete standstill. In light of the catastrophic incident that disrupted the operation of the LHC, the paper investigates the relation of temporality to the cycle of work in science, and raises the question: What kind of methodological value should we ascribe to events such as crises or breakdowns? Drawing upon and integrating classical anthropological themes with two and a half years of fieldwork at the LHC particle accelerator complex, the paper explores how the incident in September, which affected the instrument, acquaints us with the distribution of work in the laboratory. The incident discloses that the organization of science is not a homogenous ensemble, but marked by an enormous diversity of tasks and p...

Viewpoint: the End of the World at the Large Hadron Collider?

International Nuclear Information System (INIS)

Peskin, Michael E.

2008-01-01

New arguments based on astrophysical phenomena constrain the possibility that dangerous black holes will be produced at the CERN Large Hadron Collider. On 8 August, the Large Hadron Collider (LHC) at CERN injected its first beams, beginning an experimental program that will produce proton-proton collisions at an energy of 14 TeV. Particle physicists are waiting expectantly. The reason is that the Standard Model of strong, weak, and electromagnetic interactions, despite its many successes, is clearly incomplete. Theory says that the holes in the model should be filled by new physics in the energy region that will be studied by the LHC. Some candidate theories are simple quick fixes, but the most interesting ones involve new concepts of spacetime waiting to be discovered. Look up the LHC on Wikipedia, however, and you will find considerable space devoted to safety concerns. At the LHC, we will probe energies beyond those explored at any previous accelerator, and we hope to create particles that have never been observed. Couldn't we, then, create particles that would actually be dangerous, for example, ones that would eat normal matter and eventually turn the earth into a blob of unpleasantness? It is morbid fun to speculate about such things, and candidates for such dangerous particles have been suggested. These suggestions have been analyzed in an article in Reviews of Modern Physics by Jaffe, Busza, Wilczek, and Sandweiss and excluded on the basis of constraints from observation and from the known laws of physics. These conclusions have been upheld by subsequent studies conducted at CERN.

Extracting the top-quark running mass using t anti t + 1-jet events produced at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Fuster, J.; Vos, M. [IFIC, Universitat de Valencia y CSIC, Paterna (Spain); Irles, A. [Universite de Paris-Sud XI, CNRS/IN2P3, Laboratoire de l' Accelerateur Lineaire, Orsay (France); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Melini, D. [IFIC, Universitat de Valencia y CSIC, Paterna (Spain); Universidad de Granada, Departamento de Fisica Teorica y del Cosmos, Granada (Spain); Uwer, P. [Humboldt-Universitaet Berlin (Germany)

2017-11-15

We present the calculation of the next-to-leading order QCD corrections for top-quark pair production in association with an additional jet at hadron colliders, using the modified minimal subtraction scheme to renormalize the top-quark mass. The results are compared to measurements at the Large Hadron Collider run I. In particular, we determine the top-quark running mass from a fit of the theoretical results presented here to the LHC data. (orig.)

Extracting the top-quark running mass using t anti t+1-jet events produced at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Fuster, J.; Vos, M. [Valencia Univ. and CSIC, Paterna (Spain). IFIC; Irles, A. [Paris-Sud XI Univ., CNRS/IN2P3, Orsay (France). Lab. de l' Accelerateur Lineaire; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Melini, D. [Valencia Univ. and CSIC, Paterna (Spain). IFIC; Granada Univ. (Spain). Dept. de Fisica Teorica y del Cosmos; Uwer, P. [Humboldt-Univ., Berlin (Germany)

2017-04-04

We present the calculation of the next-to-leading order QCD corrections for top quark pair production in association with an additional jet at hadron colliders, using the modified minimal subtraction scheme to renormalize the top-quark mass. The results are compared to measurements at the Large Hadron Collider run I. In particular, we determine the top-quark running mass from a fit of the theoretical results presented here to the LHC data.

Hadron-hadron colliders

International Nuclear Information System (INIS)

Month, M.; Weng, W.T.

1983-01-01

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

Physics at hadron colliders: Experimental view

International Nuclear Information System (INIS)

Siegrist, J.L.

1987-08-01

The physics of the hadron-hadron collider experiment is considered from an experimental point of view. The problems encountered in determination of how well the standard model describes collider results are discussed. 53 refs., 58 figs

An investigation of triply heavy baryon production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Gomshi Nobary, M.A. [Department of Physics, Faculty of Science, Razi University, Kermanshah (Iran, Islamic Republic of) and Center for Theoretical Physics and Mathematics, AEOI, Roosbeh Building, PO Box 11365-8486, Tehran (Iran, Islamic Republic of)]. E-mail: mnobary@razi.ac.ir; Sepahvand, R. [Department of Physics, Faculty of Science, Razi University, Kermanshah (Iran, Islamic Republic of)

2006-05-01

The triply heavy baryons have a rather diverse mass range. While some of them possess considerable production rates at existing facilities, others need to be produced at future high energy colliders. Here we study the direct fragmentation production of the {omega}{sub ccc} and {omega}{sub bbb} baryons as the prototypes of triply heavy baryons at the hadron colliders with different s. We present and compare the transverse momentum distributions of the differential cross sections, p{sub T}{sup min} distributions of total cross sections and the integrated total cross sections of these states at the RHIC, the Tevatron Run II and the CERN LHC.

The large hadron collider project

International Nuclear Information System (INIS)

Maiani, L.

1999-01-01

Knowledge of the fundamental constituents of matter has greatly advanced, over the last decades. The standard theory of fundamental interactions presents us with a theoretically sound picture, which describes with great accuracy known physical phenomena on most diverse energy and distance scales. These range from 10 -16 cm, inside the nucleons, up to large-scale astrophysical bodies, including the early Universe at some nanosecond after the Big-Bang and temperatures of the order of 10 2 GeV. The picture is not yet completed, however, as we lack the observation of the Higgs boson, predicted in the 100-500 GeV range - a particle associated with the generation of particle masses and with the quantum fluctuations in the primordial Universe. In addition, the standard theory is expected to undergo a change of regime in the 10 3 GeV region, with the appearance of new families of particles, most likely associated with the onset of a new symmetry (supersymmetry). In 1994, the CERN Council approved the construction of the large hadron collider (LHC), a proton-proton collider of a new design to be installed in the existing LEP tunnel, with an energy of 7 TeV per beam and extremely large luminosity, of ∝10 34 cm -2 s -1 . Construction was started in 1996, with the additional support of the US, Japan, Russia, Canada and other European countries, making the LHC a really global project, the first one in particle physics. After a short review of the physics scenario, I report on the present status of the LHC construction. Special attention is given to technological problems such as the realization of the super-conducting dipoles, following an extensive R and D program with European industries. The construction of the large LHC detectors has required a vast R and D program by a large international community, to overcome the problems posed by the complexity of the collisions and by the large luminosity of the machine. (orig.)

Geant4 Hadronic Cascade Models and CMS Data Analysis : Computational Challenges in the LHC era

CERN Document Server

Heikkinen, Aatos

This work belongs to the field of computational high-energy physics (HEP). The key methods used in this thesis work to meet the challenges raised by the Large Hadron Collider (LHC) era experiments are object-orientation with software engineering, Monte Carlo simulation, the computer technology of clusters, and artificial neural networks. The first aspect discussed is the development of hadronic cascade models, used for the accurate simulation of medium-energy hadron-nucleus reactions, up to 10 GeV. These models are typically needed in hadronic calorimeter studies and in the estimation of radiation backgrounds. Various applications outside HEP include the medical field (such as hadron treatment simulations), space science (satellite shielding), and nuclear physics (spallation studies). Validation results are presented for several significant improvements released in Geant4 simulation tool, and the significance of the new models for computing in the Large Hadron Collider era is estimated. In particular, we es...

Advanced Superconducting Technology for Global Science The Large Hadron Collider at CERN

CERN Document Server

Lebrun, P

2002-01-01

The Large Hadron Collider (LHC), presently in construction at CERN, the European Organisation for Nuclear Research near Geneva (Switzerland), will be, upon its completion in 2005 and for the next twenty years, the most advanced research instrument of the world's high-energy physics community, providing access to the energy frontier above 1 TeV per elementary constituent. Re-using the 26.7-km circumference tunnel and infrastructure of the past LEP electron-positon collider, operated until 2000, the LHC will make use of advanced superconducting technology - high-field Nb-Ti superconducting magnets operated in superfluid helium and a cryogenic ultra-high vacuum system - to bring into collision intense beams of protons and ions at unprecedented values of center-of-mass energy and luminosity (14 TeV and 1034 cm-2.s-1, respectively with protons). After some ten years of focussed R&D, the LHC components are presently series-built in industry and procured through world-wide collaboration. After briefly recalling ...

Long-lived sleptons at the LHC and a 100 TeV proton collider

International Nuclear Information System (INIS)

Feng, Jonathan L.; Iwamoto, Sho; Shadmi, Yael; Tarem, Shlomit

2015-01-01

We study the prospects for long-lived charged particle (LLCP) searches at current and future LHC runs and at a 100 TeV pp collider, using Drell-Yan slepton pair production as an example. Because momentum measurements become more challenging for very energetic particles, we carefully treat the expected momentum resolution. At the same time, a novel feature of 100 TeV collisions is the significant energy loss of energetic muons in the calorimeter. We use this to help discriminate between muons and LLCPs. We find that the 14 TeV LHC with an integrated luminosity of 3 ab −1 can probe LLCP slepton masses up to 1.2 TeV, and a 100 TeV pp collider with 3 ab −1 can probe LLCP slepton masses up to 4 TeV, using time-of-flight measurements. These searches will have striking implications for dark matter, with the LHC definitively testing the possibility of slepton-neutralino co-annihilating WIMP dark matter, and with the LHC and future hadron colliders having a strong potential for discovering LLCPs in models with superWIMP dark matter.

Minimum Bias Measurements with the ATLAS Detector at the CERN Large Hadron Collider

CERN Document Server

Leyton, M

2009-01-01

The Large Hadron Collider (LHC) at CERN will collide bunches of protons (p) at a center-of-mass energy of sqrt(s) = 14 TeV and a rate of 40 MHz. The unprecedented collision energy and interaction rate at the LHC will allow us to explore the TeV mass scale and take a major step forward in our understanding of the fundamental nature of matter. The initial physics run of the LHC is expected to start in November 2009 and continue until the end of 2010, with collisions at sqrt(s) = 900 GeV, 7 TeV and 10 TeV. ATLAS (A Toroidal LHC ApparatuS) is a 4pi general-purpose detector designed for studying LHC collisions at the particle level. The design and layout of ATLAS are intended to cover the wide spectrum of physics signatures that are possible at the TeV mass scale. Construction and installation of the ATLAS detector at CERN are now complete. This dissertation focuses on measuring the properties of inelastic pp interactions at the LHC with the ATLAS detector. A method for measuring the central pseudorapidity den...

Department of Energy assessment of the Large Hadron Collider

International Nuclear Information System (INIS)

1996-06-01

This report summarizes the conclusions of the committee that assessed the cost estimate for the Large Hadron Collider (LHC). This proton-proton collider will be built at CERN, the European Laboratory for Particle Physics near Geneva, Switzerland. The committee found the accelerator-project cost estimate of 2.3 billion in 1995 Swiss francs, or about $2 billion US, to be adequate and reasonable. The planned project completion date of 2005 also appears achievable, assuming the resources are available when needed. The cost estimate was made using established European accounting procedures. In particular, the cost estimate does not include R and D, prototyping and testing, spare parts, and most of the engineering labor. Also excluded are costs for decommissioning the Large Electron-Positron collider (LEP) that now occupies the tunnel, modifications to the injector system, the experimental areas, preoperations costs, and CERN manpower. All these items are assumed by CERN to be included in the normal annual operations budget rather than the construction budget. Finally, contingency is built into the base estimate, in contrast to Department of Energy (DOE) estimates that explicitly identify contingency. The committee's charge, given by Dr. James F. Decker, Deputy Directory of the DOE Office of Energy Research, was to understand the basis for the LHC cost estimate, identify uncertainties, and judge the overall validity of the estimate, proposed schedule, and related issues. The committee met at CERN April 22--26, 1996. The assessment was based on the October 1995 LHC Conceptual Design Report or ''Yellow Book,'' cost estimates and formal presentations made by the CERN staff, site inspection, detailed discussions with LHC technical experts, and the committee members' considerable experience

Challenges for MSSM Higgs searches at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Carena, Marcela S.; /Fermilab; Menon, A.; /Argonne /Chicago U., EFI; Wagner, C.E.M.; /Argonne /Chicago U., EFI /KICP, Chicago /Chicago U.

2007-04-01

In this article we analyze the impact of B-physics and Higgs physics at LEP on standard and non-standard Higgs bosons searches at the Tevatron and the LHC, within the framework of minimal flavor violating supersymmetric models. The B-physics constraints we consider come from the experimental measurements of the rare B-decays b {yields} s{gamma} and B{sub u} {yields} {tau}{nu} and the experimental limit on the B{sub s} {yields} {mu}{sup +}{mu}{sup -} branching ratio. We show that these constraints are severe for large values of the trilinear soft breaking parameter A{sub t}, rendering the non-standard Higgs searches at hadron colliders less promising. On the contrary these bounds are relaxed for small values of A{sub t} and large values of the Higgsino mass parameter {mu}, enhancing the prospects for the direct detection of non-standard Higgs bosons at both colliders. We also consider the available ATLAS and CMS projected sensitivities in the standard model Higgs search channels, and we discuss the LHC's ability in probing the whole MSSM parameter space. In addition we also consider the expected Tevatron collider sensitivities in the standard model Higgs h {yields} b{bar b} channel to show that it may be able to find 3 {sigma} evidence in the B-physics allowed regions for small or moderate values of the stop mixing parameter.

Taking Energy to the Physics Classroom from the Large Hadron Collider at CERN

Science.gov (United States)

Cid, Xabier; Cid, Ramon

2009-01-01

In 2008, the greatest experiment in history began. When in full operation, the Large Hadron Collider (LHC) at CERN will generate the greatest amount of information that has ever been produced in an experiment before. It will also reveal some of the most fundamental secrets of nature. Despite the enormous amount of information available on this…

LHC physics

National Research Council Canada - National Science Library

Binoth, T

2012-01-01

"Exploring the phenomenology of the Large Hadron Collider (LHC) at CERN, LHC Physics focuses on the first years of data collected at the LHC as well as the experimental and theoretical tools involved...

A Silicon Strip Detector for the Phase II High Luminosity Upgrade of the ATLAS Detector at the Large Hadron Collider

CERN Document Server

INSPIRE-00425747; McMahon, Stephen J

2015-01-01

ATLAS is a particle physics experiment at the Large Hadron Collider (LHC) that detects proton-proton collisions at a centre of mass energy of 14 TeV. The Semiconductor Tracker is part of the Inner Detector, implemented using silicon microstrip detectors with binary read-out, providing momentum measurement of charged particles with excellent resolution. The operation of the LHC and the ATLAS experiment started in 2010, with ten years of operation expected until major upgrades are needed in the accelerator and the experiments. The ATLAS tracker will need to be completely replaced due to the radiation damage and occupancy of some detector elements and the data links at high luminosities. These upgrades after the first ten years of operation are named the Phase-II Upgrade and involve a re-design of the LHC, resulting in the High Luminosity Large Hadron Collider (HL-LHC). This thesis presents the work carried out in the testing of the ATLAS Phase-II Upgrade electronic systems in the future strips tracker a...

Fast symplectic map tracking for the CERN Large Hadron Collider

Directory of Open Access Journals (Sweden)

Dan T. Abell

2003-06-01

Full Text Available Tracking simulations remain the essential tool for evaluating how multipolar imperfections in ring magnets restrict the domain of stable phase-space motion. In the Large Hadron Collider (LHC at CERN, particles circulate at the injection energy, when multipole errors are most significant, for more than 10^{7} turns, but systematic tracking studies are limited to a small fraction of this total time—even on modern computers. A considerable speedup is expected by replacing element-by-element tracking with the use of a symplectified one-turn map. We have applied this method to the realistic LHC lattice, version 6, and report here our results for various map orders, with special emphasis on precision and speed.

A Large Hadron Electron Collider at CERN

CERN Document Server

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

2012-01-01

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

Aperture meter for the Large Hadron Collider

International Nuclear Information System (INIS)

Mueller, G.J.; Fuchsberger, K.; Redaelli, S.

2012-01-01

The control of the high intensity beams of the CERN Large Hadron Collider (LHC) is particular challenging and requires a good modeling of the machine and monitoring of various machine parameters. During operation it is crucial to ensure a minimal distance between the beam edge and the aperture of sensitive equipment, e.g. the superconducting magnets, which in all cases must be in the shadow of the collimator's that protect the machine. Possible dangerous situations must be detected as soon as possible. In order to provide the operator with information about the current machine bottlenecks an aperture meter application was developed based on the LHC online modeling tool-chain. The calculation of available free aperture takes into account the best available optics and aperture model as well as the relevant beam measurements. This paper describes the design and integration of this application into the control environment and presents results of the usage in daily operation and from validation measurements. (authors)

Stop Lepton Associated Production at Hadron Colliders

CERN Document Server

Alves, A; Plehn, Tilman

2003-01-01

At hadron colliders, the search for R-parity violating supersymmetry can probe scalar masses beyond what is covered by pair production processes. We evaluate the next-to-leading order SUSY-QCD corrections to the associated stop or sbottom production with a lepton through R-parity violating interactions. We show that higher order corrections render the theoretical predictions more stable with respect to variations of the renormalization and factorization scales and that the total cross section is enhanced by a factor up to 70% at the Tevatron and 50% at the LHC. We investigate in detail how the heavy supersymmetric states decouple from the next-to-leading order process, which gives rise to a theory with an additional scalar leptoquark. In this scenario the inclusion of higher order QCD corrections increases the Tevatron reach on leptoquark masses by up to 40 GeV and the LHC reach by up to 200 GeV.

The feasibility of experiments at high luminosity at the large hadron collider

International Nuclear Information System (INIS)

Mulvey, J.H.

1988-01-01

The studies reported in this volume extend some of those made during Workshop on Physics at Future Accelerators held at La Thuile and CERN in January 1987 (CERN 87-07, Vol. 1 and 2). They consider the feasibility of performing experiments with a 16 TeV proton-proton collider, the Large Hadron Collider (LHC), at luminosities as high as 5.10 34 cm -2 s -1 . To illustrate the difficulties and the extent to which the potential for discovery at the LHC might be improved by such a step, three specific topics were chosen: searches for a) a massive Higgs boson, b) SUSY gluinos and squarks, and c) a new Z'. Following the Summary Report of the High Luminosity Study Group are papers discussing a possible detector system, radiation levels, and the analyses leading to estimated mass-limits for the searches. (orig.)

SUSY-QCD corrections to Higgs boson production at hadron colliders

International Nuclear Information System (INIS)

Djouadi, A.; Spira, M.

1999-12-01

We analyze the next-to-leading order SUSY-QCD corrections to the production of Higgs particles at hadron colliders in supersymmetric extensions of the standard model. Besides the standard QCD corrections due to gluon exchange and emission, genuine supersymmetric corrections due to the virtual exchange of squarks and gluinos are present. At both the Tevatron and the LHC, these corrections are found to be small in the Higgs-strahlung, Drell-Yan-like Higgs pair production and vector boson fusion processes. (orig.)

How to Find a Hidden World at the Large Hadron Collider

CERN Document Server

Wells, James D.

2008-01-01

I discuss how the Large Hadron Collider era should broaden our view of particle physics research, and apply this thinking to the case of Hidden Worlds. I focus on one of the simplest representative cases of a Hidden World, and detail the rich implications it has for LHC physics, including universal suppression of Higgs boson production, trans-TeV heavy Higgs boson signatures, heavy-to-light Higgs boson decays, weakly coupled exotic gauge bosons, and Higgs boson decays to four fermions via light exotic gauge bosons. Some signatures may be accessible in the very early stages of collider operation, whereas others motivate a later high-lumonosity upgrade.

Investigation of collimator materials for the High Luminosity Large Hadron Collider

CERN Document Server

AUTHOR|(CDS)2085459; Bertarelli, Alessandro; Redaelli, Stefano

This PhD thesis work has been carried out at the European Organisation for Nuclear Research (CERN), Geneva, Switzerland), in the framework of the High Luminosity (HL) upgrade of the Large Hadron Collider (LHC). The HL-LHC upgrade will bring the accelerator beyond the nominal performance: it is planning to reach higher stored beam energy up to 700 MJ, through more intense proton beams. The present multi-stage LHC collimation system was designed to handle 360 MJ stored beam energy and withstand realistic losses only for this nominal beam. Therefore, the challenging HL-LHC beam parameters pose strong concerns for beam collimation, which call for important upgrades of the present system. The objective of this thesis is to provide solid basis for optimum choices of materials for the different collimators that will be upgraded for the baseline layout of the HL-LHC collimation system. To achieve this goal, material-related limitations of the present system are identified and novel advanced composite materials are se...

SEARCHING FOR HIGGS BOSONS AND NEW PHYSICS AT HADRON COLLIDERS

International Nuclear Information System (INIS)

Chung Kao

2007-01-01

The objectives of research activities in particle theory are predicting the production cross section and decay branching fractions of Higgs bosons and new particles at hadron colliders, developing techniques and computer software to discover these particles and to measure their properties, and searching for new phenomena and new interactions at the Fermilab Tevatron and the CERN Large Hadron Collider. The results of our project could lead to the discovery of Higgs bosons, new particles, and signatures for new physics, or we will be able to set meaningful limits on important parameters in particle physics. We investigated the prospects for the discovery at the CERN Large Hadron Collider of Higgs bosons and supersymmetric particles. Promising results are found for the CP-odd pseudoscalar (A 0 ) and the heavier CP-even scalar (H 0 ) Higgs bosons with masses up to 800 GeV. Furthermore, we study properties of the lightest neutralino (χ 0 ) and calculate its cosmological relic density in a supersymmetric U(1)(prime) model as well as the muon anomalous magnetic moment a μ = (g μ -2)/2 in a supersymmetric U(1)(prime) model. We found that there are regions of the parameter space that can explain the experimental deviation of a μ from the Standard Model calculation and yield an acceptable cold dark matter relic density without conflict with collider experimental constraints. Recently, we presented a complete next-to-leading order (NLO) calculation for the total cross section of inclusive Higgs pair production via bottom-quark fusion (b(bar b) to hh) at the CERN Large Hadron Collider (LHC) in the Standard Model and the minimal supersymmetric model. We plan to predict the Higgs pair production rate and to study the trilinear coupling among the Higgs bosons. In addition, we have made significant contributions in B physics, single top production, charged Higgs search at the Fermilab as well as in grid computing for both D0 and ATLAS

Physics with the collider detectors at RHIC and the LHC

International Nuclear Information System (INIS)

Thomas, J.; Hallman, T.

1995-01-01

On January 8, 1995, over 180 participants gathered to hear the QM95 preconference workshop on 'Physics with the Collider Detectors at RHIC and the LHC'. The goal was to bring together the experimentalists from a wide community of hadron and heavy ion collider detector collaborations. The speakers were encouraged to present the current status of their detectors, with all the blemishes, and the audience was encouraged to share their successes and failures in approaching similar detector design issues. The presentations were excellent and the discussions were lively and stimulating. The editors hope that the reader will find these proceedings to be equally stimulating. Separate abstracts have been submitted to the energy database from articles in this report

Physics with the collider detectors at RHIC and the LHC

Energy Technology Data Exchange (ETDEWEB)

Thomas, J.; Hallman, T. [eds.

1995-07-15

On January 8, 1995, over 180 participants gathered to hear the QM95 preconference workshop on `Physics with the Collider Detectors at RHIC and the LHC`. The goal was to bring together the experimentalists from a wide community of hadron and heavy ion collider detector collaborations. The speakers were encouraged to present the current status of their detectors, with all the blemishes, and the audience was encouraged to share their successes and failures in approaching similar detector design issues. The presentations were excellent and the discussions were lively and stimulating. The editors hope that the reader will find these proceedings to be equally stimulating. Separate abstracts have been submitted to the energy database from articles in this report.

Unparticle self-interactions at the Large Hadron Collider

International Nuclear Information System (INIS)

Bergstroem, Johannes; Ohlsson, Tommy

2009-01-01

We investigate the effect of unparticle self-interactions at the Large Hadron Collider (LHC). Especially, we discuss the three-point correlation function, which is determined by conformal symmetry up to a constant, and study its relation to processes with four-particle final states. These processes could be used as a favorable way to look for unparticle physics, and for weak enough couplings to the standard model, even the only way. We find updated upper bounds on the cross sections for unparticle-mediated 4γ final states at the LHC and novel upper bounds for the corresponding 2γ2l and 4l final states. The size of the allowed cross sections obtained are comparably large for large values of the scaling dimension of the unparticle sector, but they decrease with decreasing values of this parameter. In addition, we present relevant distributions for the different final states, enabling the possible identification of the unparticle scaling dimension if there was to be a large number of events of such final states at the LHC.

Cryogenic Studies for the Proposed CERN Large Hadron Electron Collider (LHeC)

CERN Document Server

Haug, F

2011-01-01

The LHeC (Large Hadron electron Collider) is a proposed future colliding beam facility for lepton-nucleon scattering particle physics at CERN. A new 60 GeV electron accelerator will be added to the existing 27 km circumference 7 TeV LHC for collisions of electrons with protons and heavy ions. Two basic design options are being pursued. The first is a circular accelerator housed in the existing LHC tunnel which is referred to as the "Ring-Ring" version. Low field normal conducting magnets guide the particle beam while superconducting (SC) RF cavities cooled to 2 K are installed at two opposite locations at the LHC tunnel to accelerate the beams. For this version in addition a 10 GeV re-circulating SC injector will be installed. In total four refrigerators with cooling capacities between 1.2 kW and 3 kW @ 4.5 K are needed. The second option, referred to as the "Linac-Ring" version consists of a race-track re-circulating energy-recovery type machine with two 1 km long straight acceleration sections. The 944 hi...

CMS Hadron Endcap Calorimeter Upgrade Studies for Super-LHC

International Nuclear Information System (INIS)

Bilki, Burak

2011-01-01

When the Large Hadron Collider approaches Super-LHC conditions above a luminosity of 10 34 cm -2 s -1 , the scintillator tiles of the CMS Hadron Endcap calorimeters will lose their efficiencies. As a radiation hard solution, the scintillator tiles are planned to be replaced by quartz plates. In order to improve the efficiency of the photodetection, various methods were investigated including radiation hard wavelength shifters, p-terphenyl or 4% gallium doped zinc oxide. We constructed a 20 layer calorimeter prototype with pTp coated plates of size 20 cm x 20 cm, and tested the hadronic and the electromagnetic capabilities at the CERN H2 beam-line. The beam tests revealed a substantial light collection increase with pTp or ZnO:Ga deposited quartz plates. Here we report on the current R and D for a viable endcap calorimeter solution for CMS with beam tests and radiation damage studies.

A table-top LHC

CERN Multimedia

Barbara Warmbein

2011-01-01

Many years ago, when ATLAS was no more than a huge empty underground cavern and Russian artillery shell casings were being melted down to become part of the CMS calorimetry system, science photographer Peter Ginter started documenting the LHC’s progress. He was there when special convoys of equipment crossed the Jura at night, when cranes were lowering down detector slices and magnet coils were being wound in workshops. Some 18 years of LHC history have been documented by Ginter, and the result has just come out as a massive coffee table book full of double-page spreads of Ginter’s impressive images.   The new coffee table book, LHC: the Large Hadron Collider. Published by the Austrian publisher Edition Lammerhuber in cooperation with CERN and UNESCO Publishing, LHC: the Large Hadron Collider is an unusual piece in the company’s portfolio. As the publisher’s first science book, LHC: the Large Hadron Collider weighs close to five kilos and comes in a s...

Radial scaling in inclusive jet production at hadron colliders

Science.gov (United States)

Taylor, Frank E.

2018-03-01

Inclusive jet production in p-p and p ¯ -p collisions shows many of the same kinematic systematics as observed in single-particle inclusive production at much lower energies. In an earlier study (1974) a phenomenology, called radial scaling, was developed for the single-particle inclusive cross sections that attempted to capture the essential underlying physics of pointlike parton scattering and the fragmentation of partons into hadrons suppressed by the kinematic boundary. The phenomenology was successful in emphasizing the underlying systematics of the inclusive particle productions. Here we demonstrate that inclusive jet production at the Large Hadron Collider (LHC) in high-energy p-p collisions and at the Tevatron in p ¯ -p inelastic scattering shows similar behavior. The ATLAS inclusive jet production plotted as a function of this scaling variable is studied for √s of 2.76, 7 and 13 TeV and is compared to p ¯ -p inclusive jet production at 1.96 TeV measured at the CDF and D0 at the Tevatron and p-Pb inclusive jet production at the LHC ATLAS at √sNN=5.02 TeV . Inclusive single-particle production at Fermi National Accelerator Laboratory fixed target and Intersecting Storage Rings energies are compared to inclusive J /ψ production at the LHC measured in ATLAS, CMS and LHCb. Striking common features of the data are discussed.

Prompt D*+ production in proton-proton and lead-lead collisions, measured with the ALICE experiment at the CERN Large Hadron Collider

NARCIS (Netherlands)

de Rooij, R. S.

2013-01-01

In this thesis the results are presented of the first measurements of the D*+ meson nuclear modification factor RAA in heavy ion collisions at the Large Hadron Collider (LHC) using the ALICE (A Large Ion Collider Experiment) detector at CERN. These open charmed mesons are a useful tool to

From the LHC to Future Colliders

Energy Technology Data Exchange (ETDEWEB)

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

2010-06-11

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

B factory with hadron colliders

International Nuclear Information System (INIS)

Lockyer, N.S.

1990-01-01

The opportunities to study B physics in a hadron collider are discussed. Emphasis is placed on the technological developments necessary for these experiments. The R and D program of the Bottom Collider Detector group is reviewed. (author)

The case for future hadron colliders from B → K (*) μ + μ - decays

Science.gov (United States)

Allanach, B. C.; Gripaios, Ben; You, Tevong

2018-03-01

Recent measurements in B → K (*) μ + μ - decays are somewhat discrepant with Standard Model predictions. They may be harbingers of new physics at an energy scale potentially accessible to direct discovery. We estimate the sensitivity of future hadron colliders to the possible new particles that may be responsible for the anomalies at tree-level: leptoquarks or Z's. We consider luminosity upgrades for a 14 TeV LHC, a 33 TeV LHC, and a 100 TeV pp collider such as the FCC-hh. In the most conservative and pessimistic models, for narrow particles with perturbative couplings, Z' masses up to 20 TeV and leptoquark masses up to 41 TeV may in principle explain the anomalies. Coverage of Z' models is excellent: a 33 TeV 1 ab-1 LHC is expected to cover most of the parameter space up to 8 TeV in mass, whereas the 100 TeV FCC-hh with 10 ab-1 will cover all of it. A smaller portion of the leptoquark parameter space is covered by future colliders: for example, in a μ + μ - jj di-leptoquark search, a 100 TeV 10 ab-1 collider has a projected sensitivity up to leptoquark masses of 12 TeV (extendable to 21 TeV with a strong coupling for single leptoquark production).

A Large Hadron Electron Collider at CERN: Report on the Physics and Design Concepts for Machine and Detector

CERN Document Server

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

2012-01-01

The physics programme and the design are described of a new collider for particle and nuclear physics, the Large Hadron Electron Collider (LHeC), in which a newly built electron beam of 60 GeV, up to possibly 140 GeV, energy collides with the intense hadron beams of the LHC. Compared to HERA, the kinematic range covered is extended by a factor of twenty in the negative four-momentum squared, $Q^2$, and in the inverse Bjorken $x$, while with the design luminosity of $10^{33}$ cm$^{-2}$s$^{-1}$ the LHeC is projected to exceed the integrated HERA luminosity by two orders of magnitude. The physics programme is devoted to an exploration of the energy frontier, complementing the LHC and its discovery potential for physics beyond the Standard Model with high precision deep inelastic scattering measurements. These are designed to investigate a variety of fundamental questions in strong and electroweak interactions. The physics programme also includes electron-deuteron and electron-ion scattering in a $(Q^2, 1/x)$ ran...

Conceptual design of hollow electron lenses for beam halo control in the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Stancari, Giulio [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Previtali, Valentina [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Valishev, Alexander [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Bruce, Roderik [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Redaelli, Stefano [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Rossi, Adriana [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Salvachua Ferrando, Belen [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

2014-06-26

Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. We are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were checked to ensure that undesired effects were suppressed. Hardware specifications were based on the Tevatron devices and on preliminary engineering integration studies in the LHC machine. Required resources and a possible timeline were also outlined, together with a brief discussion of alternative halo-removal schemes and of other possible uses of electron lenses to improve the performance of the LHC.

Higgs Bosons, Electroweak Symmetry Breaking, and the Physics of the Large Hadron Collider

CERN Document Server

Quigg, Chris

2007-01-01

The Large Hadron Collider, a 7 + 7 TeV proton-proton collider under construction at CERN (the European Laboratory for Particle Physics in Geneva), will take experiments squarely into a new energy domain where mysteries of the electroweak interaction will be unveiled. What marks the 1-TeV scale as an important target? Why is understanding how the electroweak symmetry is hidden important to our conception of the world around us? What expectations do we have for the agent that hides the electroweak symmetry? Why do particle physicists anticipate a great harvest of discoveries within reach of the LHC?

The New Superfluid Helium Cryostats for the Short Straight Sections of the CERN Large Hadron Collider (LHC)

CERN Document Server

Cameron, W; Kurtyka, T; Parma, Vittorio; Renaglia, T; Rifflet, J M; Rohmig, P; Skoczen, Blazej; Tortschanoff, Theodor; Trilhe, P; Védrine, P; Vincent, D

1998-01-01

The lattice of the CERN Large Hadron Collider (LHC) contains 364 Short Straight Section (SSS) units, one in every 53 m long half-cell. An SSS consists of three major assemblies: the standard cryostat section, the cryogenic service module, and the jumper connection. The standard cryostat section of an SSS contains the twin aperture high-gradient superconducting quadrupole and two pairs of superconducting corrector magnets, operating in pressurized helium II at 1.9 K. Components for isolating cryostat insulation vacuum, and the cryogenic supply lines, have to be foreseen. Special emphasis is given to the design changes of the SSS following adoption of an external cryogenic supply line (QRL). A jumper connection connects the SSS to the QRL, linking all the cryogenic tubes necessary for the local full-cell cooling loop [at every second SSS]. The jumper is connected to one end of the standard cryostat section via the cryogenic service module, which also houses beam diagnostics, current feedthroughs, and instrument...

Upgrade of the ATLAS hadronic Tile Calorimeter for the High luminosity LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00127668; The ATLAS collaboration

2017-01-01

The Tile Calorimeter (TileCal) is the hadronic calorimeter of ATLAS covering the central region of the ATLAS experiment. TileCal is a sampling calorimeter with steel as absorber and scintillators as active medium. The scintillators are read-out by wavelength shifting fibers coupled to photomultiplier tubes (PMT). The analogue signals from the PMTs are amplified, shaped and digitized by sampling the signal every 25 ns. The High Luminosity Large Hadron Collider (HL-LHC) will have a peak luminosity of 5 1034cm2s1, five times higher than the design luminosity of the LHC. TileCal will undergo a major replacement of its on- and off-detector electronics for the high luminosity programme of the LHC starting in 2026. All signals will be digitized and then transferred directly to the off-detector electronics, where the signals will be reconstructed, stored, and sent to the first level of trigger at a rate of 40 MHz. This will provide better precision of the calorimeter signals used by the trigger system and will allow ...

Upgrade of the ATLAS hadronic Tile Calorimeter for the High luminosity LHC

CERN Document Server

Solodkov, Alexander; The ATLAS collaboration

2017-01-01

The Tile Calorimeter (TileCal) is the hadronic calorimeter of ATLAS covering the central region of the ATLAS experiment. TileCal is a sampling calorimeter with steel as absorber and scintillators as active medium. The scintillators are read-out by wavelength shifting fibers coupled to photomultiplier tubes (PMT). The analogue signals from the PMTs are amplified, shaped and digitized by sampling the signal every 25 ns. The High Luminosity Large Hadron Collider (HL-LHC) will have a peak luminosity of 5x10ˆ34 cm-2s-1, five times higher than the design luminosity of the LHC. TileCal will undergo a major replacement of its on- and off-detector electronics for the high luminosity programme of the LHC starting in 2026. All signals will be digitized and then transferred directly to the off-detector electronics, where the signals will be reconstructed, stored, and sent to the first level of trigger at a rate of 40 MHz. This will provide better precision of the calorimeter signals used by the trigger system and will a...

The Hunt for New Physics at the Large Hadron Collider

CERN Document Server

Nath, Pran; Davoudiasl, Hooman; Dutta, Bhaskar; Feldman, Daniel; Liu, Zuowei; Han, Tao; Langacker, Paul; Mohapatra, Rabi; Valle, Jose; Pilaftsis, Apostolos; Zerwas, Dirk; AbdusSalam, Shehu; Adam-Bourdarios, Claire; Aguilar-Saavedra, J A; Allanach, Benjamin; Altunkaynak, B; Anchordoqui, Luis A; Baer, Howard; Bajc, Borut; Buchmueller, O; Carena, M; Cavanaugh, R; Chang, S; Choi, Kiwoon; Csaki, C; Dawson, S; de Campos, F; De Roeck, A; Duhrssen, M; Eboli, O J.P; Ellis, J R; Flacher, H; Goldberg, H; Grimus, W; Haisch, U; Heinemeyer, S; Hirsch, M; Holmes, M; Ibrahim, Tarek; Isidori, G; Kane, Gordon; Kong, K; Lafaye, Remi; Landsberg, G; Lavoura, L; Lee, Jae Sik; Lee, Seung J; Lisanti, M; Lust, Dieter; Magro, M B; Mahbubani, R; Malinsky, M; Maltoni, Fabio; Morisi, S; Muhlleitner, M M; Mukhopadhyaya, B; Neubert, M; Olive, K A; Perez, Gilad; Perez, Pavel Fileviez; Plehn, T; Ponton, E; Porod, Werner; Quevedo, F; Rauch, M; Restrepo, D; Rizzo, T G; Romao, J C; Ronga, F J; Santiago, Jose; Schechter, J; Senjanovic, G; Shao, J; Spira, M; Stieberger, S; Sullivan, Zack; Tait, Tim M P; Tata, Xerxes; Taylor, T R; Toharia, M; Wacker, J; Wagner, C E.M; Wang, Lian-Tao; Weiglein, G; Zeppenfeld, D; Zurek, K

2010-01-01

The Large Hadron Collider presents an unprecedented opportunity to probe the realm of new physics in the TeV region and shed light on some of the core unresolved issues of particle physics. These include the nature of electroweak symmetry breaking, the origin of mass, the possible constituent of cold dark matter, new sources of CP violation needed to explain the baryon excess in the universe, the possible existence of extra gauge groups and extra matter, and importantly the path Nature chooses to resolve the hierarchy problem - is it supersymmetry or extra dimensions. Many models of new physics beyond the standard model contain a hidden sector which can be probed at the LHC. Additionally, the LHC will be a top factory and accurate measurements of the properties of the top and its rare decays will provide a window to new physics. Further, the LHC could shed light on the origin of neutralino masses if the new physics associated with their generation lies in the TeV region. Finally, the LHC is also a laboratory ...

Development of superconducting links for the Large Hadron Collider machine

Science.gov (United States)

Ballarino, Amalia

2014-04-01

In the framework of the upgrade of the Large Hadron Collider (LHC) machine, new superconducting lines are being developed for the feeding of the LHC magnets. The proposed electrical layout envisages the location of the power converters in surface buildings, and the transfer of the current from the surface to the LHC tunnel, where the magnets are located, via superconducting links containing tens of cables feeding different circuits and transferring altogether more than 150 kA. Depending on the location, the links will have a length ranging from 300 m to 500 m, and they will span a vertical distance of about 80 m. An overview of the R&D program that has been launched by CERN is presented, with special attention to the development of novel types of cables made from MgB2 and high temperature superconductors (Bi-2223 and REBCO) and to the results of the tests performed on prototype links. Plans for future activities are presented, together with a timeline for potential future integration in the LHC machine.

Development of superconducting links for the Large Hadron Collider machine

CERN Document Server

Ballarino, A

2014-01-01

In the framework of the upgrade of the Large Hadron Collider (LHC) machine, new superconducting lines are being developed for the feeding of the LHC magnets. The proposed electrical layout envisages the location of the power converters in surface buildings, and the transfer of the current from the surface to the LHC tunnel, where the magnets are located, via superconducting links containing tens of cables feeding different circuits and transferring altogether more than 150 kA. Depending on the location, the links will have a length ranging from 300 m to 500 m, and they will span a vertical distance of about 80 m. An overview of the R&D program that has been launched by CERN is presented, with special attention to the development of novel types of cables made from MgB 2 and high temperature superconductors (Bi-2223 and REBCO) and to the results of the tests performed on prototype links. Plans for future activities are presented, together with a timeline for potential future integration in the LHC machine.

Heavy-ion physics with the ALICE experiment at the CERN Large Hadron Collider.

Science.gov (United States)

Schukraft, J

2012-02-28

After close to 20 years of preparation, the dedicated heavy-ion experiment A Large Ion Collider Experiment (ALICE) took first data at the CERN Large Hadron Collider (LHC) accelerator with proton collisions at the end of 2009 and with lead nuclei at the end of 2010. After a short introduction into the physics of ultra-relativistic heavy-ion collisions, this article recalls the main design choices made for the detector and summarizes the initial operation and performance of ALICE. Physics results from this first year of operation concentrate on characterizing the global properties of typical, average collisions, both in proton-proton (pp) and nucleus-nucleus reactions, in the new energy regime of the LHC. The pp results differ, to a varying degree, from most quantum chromodynamics-inspired phenomenological models and provide the input needed to fine tune their parameters. First results from Pb-Pb are broadly consistent with expectations based on lower energy data, indicating that high-density matter created at the LHC, while much hotter and larger, still behaves like a very strongly interacting, almost perfect liquid.

Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

CERN Document Server

Bruce, R.; Boccone, V.; Bracco, C.; Brugger, M.; Cauchi, M.; Cerutti, F.; Deboy, D.; Ferrari, A.; Lari, L.; Marsili, A.; Mereghetti, A.; Mirarchi, D.; Quaranta, E.; Redaelli, S.; Robert-Demolaize, G.; Rossi, A.; Salvachua, B.; Skordis, E.; Tambasco, C.; Valentino, G.; Weiler, T.; Vlachoudis, V.; Wollmann, D.

2014-08-21

The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010--2013, the LHC was routinely storing protons at 3.5--4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An un-controlled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multi-stage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the co...

Fault Tracking of the Superconducting Magnet System at the CERN Large Hadron Collider

CERN Document Server

Griesemer, Tobias

2016-03-25

The Large Hadron Collider (LHC) at CERN is one of the most complex machines ever built. It is used to explore the mysteries of the universe by reproducing conditions of the big bang. High energy particles are collide in particle detectors and as a result of the collision process secondary particles are created. New particles could be discovered during this process. The operation of such a machine is not straightforward and is subject to many different types of failures. A model of LHC operation needs to be defined in order to understand the impact of the various failures on availability. As an example a typical operational cycle is described: the beams are first injected, then accelerated, and finally brought into collisions. Under nominal conditions, beams should be in collision (so-called ‘stable beams’ period) for about 10 hours and then extracted onto a beam dump block. In case of a failure, the Machine Protection Systems ensure safe extraction of the beams. From the experience in LHC Run 1 (2009 - 20...

Physics at Future Colliders

CERN Document Server

Ellis, John R.

1999-01-01

After a brief review of the Big Issues in particle physics, we discuss the contributions to resolving that could be made by various planned and proposed future colliders. These include future runs of LEP and the Fermilab Tevatron collider, B factories, RHIC, the LHC, a linear electron-positron collider, an electron-proton collider in the LEP/LHC tunnel, a muon collider and a future larger hadron collider (FLHC). The Higgs boson and supersymmetry are used as benchmarks for assessing their capabilities. The LHC has great capacities for precision measurements as well as exploration, but also shortcomings where the complementary strengths of a linear electron-positron collider would be invaluable. It is not too soon to study seriously possible subsequent colliders.

Spin rotation and depolarization of high-energy particles in crystals at Hadron Collider (LHC) and Future Circular Collider (FCC) energies and the possibility to measure the anomalous magnetic moments of short-lived particles

CERN Document Server

Baryshevsky, V.G.

2015-01-01

We study the phenomena of spin rotation and depolarization of high-energy particles in crystals in the range of high energies that will be available at Hadron Collider (LHC) and Future Circular Collider (FCC). It is shown that these phenomena can be used to measure the anomalous magnetic moments of short-lived particles in this range of energies. We also demonstrate that the phenomenon of particle spin depolarization in crystals provides a unique possibility of measuring the anomalous magnetic moment of negatively-charged particles (e.g., beauty baryons), for which the channeling effect is hampered due to far more rapid dechanneling as compared to that for positively-charged particles. Channeling of particles in either straight or bent crystals with polarized nuclei could be used for polarization and the analysis thereof of high-energy particles.

submitter Training Behavior of the Main Dipoles in the Large Hadron Collider

CERN Document Server

Todesco, Ezio; Bajko, Marta; Bottura, Luca; Bruning, Oliver; De Rijk, Gijs; Fessia, Paolo; Hagen, Per; Naour, Sandrine Le; Modena, Michele; Perez, Juan Carlos; Rossi, Lucio; Schmidt, Rudiger; Siemko, Andrzej; Tock, Jean-Philippe; Tommasini, Davide; Verweij, Arjan; Willering, Gerard

2017-01-01

In 2015, the 1232 Nb-Ti dipole magnets in the Large Hadron Collider (LHC) have been commissioned to 7.8 T operational field, with 172 quenches. More than 80% of these quenches occurred in the magnets of one of the three cold mass assemblers (3000 series), confirming what was already observed in 2008. In this paper, the recent analysis carried out on the quench performance of the Large Hadron Collider dipole magnets is reported, including the individual reception tests and the 2008 and 2015 commissioning campaigns, to better understand the above-mentioned anomaly and give an outlook for future operation and possible increase of the operational field. The lower part of the quench probability spectrum is compatible with Gaussian distributions; therefore, the training curve can be fit through error functions. An essential ingredient in this analysis is the estimate of the error to be associated with the training data due to sampling of rare events, allowing to test different hypothesis. Using this approach, an es...

Simulations of fast crab cavity failures in the high luminosity Large Hadron Collider

Science.gov (United States)

Yee-Rendon, Bruce; Lopez-Fernandez, Ricardo; Barranco, Javier; Calaga, Rama; Marsili, Aurelien; Tomás, Rogelio; Zimmermann, Frank; Bouly, Frédéric

2014-05-01

Crab cavities (CCs) are a key ingredient of the high luminosity Large Hadron Collider (HL-LHC) project for increasing the luminosity of the LHC. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of the order of a few LHC turns and considering the significant stored energy in the HL-LHC beam, CC failures represent a serious threat in regard to LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, the one needed to dump the beam. The simulations assume a quasistationary-state distribution to assess the particles losses for the HL-LHC. These distributions produce beam losses below the safe operation threshold for Gaussian tails, while, for non-Gaussian tails are on the same order of the limit. Additionally, some mitigation strategies are studied for reducing the damage caused by the CC failures.

Simulations of fast crab cavity failures in the high luminosity Large Hadron Collider

Directory of Open Access Journals (Sweden)

Bruce Yee-Rendon

2014-05-01

Full Text Available Crab cavities (CCs are a key ingredient of the high luminosity Large Hadron Collider (HL-LHC project for increasing the luminosity of the LHC. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of the order of a few LHC turns and considering the significant stored energy in the HL-LHC beam, CC failures represent a serious threat in regard to LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, the one needed to dump the beam. The simulations assume a quasistationary-state distribution to assess the particles losses for the HL-LHC. These distributions produce beam losses below the safe operation threshold for Gaussian tails, while, for non-Gaussian tails are on the same order of the limit. Additionally, some mitigation strategies are studied for reducing the damage caused by the CC failures.

Z-Z' mixing effects in W±-boson pair production processes at hadron and lepton high-energy colliders

International Nuclear Information System (INIS)

Bobovnikov, I.D.; Pankov, A.A.

2016-01-01

The potential to search for Z−Z' mixing in the W ± -boson pair production processes in proton-proton and electron-positron collisions at the Large Hadron Collider (LHC) and International Linear Collider (ILC), respectively, was studied. We found that the W ± -boson pair production processes are very sensitive to Z−Z' mixing angle, and their measurements at current and future collider experiments allow one to improve the present limits on Z−Z' mixing for the investigated models with extended gauge sector. The LHC at nominal energy and integrated luminosity, 14 TeV and 100 fb -1 , can provide a much more precise information on Z-Z' mixing and Z 2 mass, M 2 , with respect to those which can be obtained at the lepton collider ILC (0.5 TeV)

Advanced superconducting technology for global science: The Large Hadron Collider at CERN

Science.gov (United States)

Lebrun, Ph.

2002-05-01

The Large Hadron Collider (LHC), presently in construction at CERN, the European Organization for Nuclear Research near Geneva (Switzerland), will be, upon its completion in 2005 and for the next twenty years, the most advanced research instrument of the world's high-energy physics community, providing access to the energy frontier above 1 TeV per elementary constituent. Re-using the 26.7-km circumference tunnel and infrastructure of the past LEP electron-positon collider, operated until 2000, the LHC will make use of advanced superconducting technology-high-field Nb-Ti superconducting magnets operated in superfluid helium and a cryogenic ultra-high vacuum system-to bring into collision intense beams of protons and ions at unprecedented values of center-of-mass energy and luminosity (14 TeV and 1034 cm-2ṡs-1, respectively with protons). After some ten years of focussed R&D, the LHC components are presently series-built in industry and procured through world-wide collaboration. After briefly recalling the physics goals, performance challenges and design choices of the machine, we describe its major technical systems, with particular emphasis on relevant advances in the key technologies of superconductivity and cryogenics, and report on its construction progress.

Grid computing in pakistan and: opening to large hadron collider experiments

International Nuclear Information System (INIS)

Batool, N.; Osman, A.; Mahmood, A.; Rana, M.A.

2009-01-01

A grid computing facility was developed at sister institutes Pakistan Institute of Nuclear Science and Technology (PINSTECH) and Pakistan Institute of Engineering and Applied Sciences (PIEAS) in collaboration with Large Hadron Collider (LHC) Computing Grid during early years of the present decade. The Grid facility PAKGRID-LCG2 as one of the grid node in Pakistan was developed employing mainly local means and is capable of supporting local and international research and computational tasks in the domain of LHC Computing Grid. Functional status of the facility is presented in terms of number of jobs performed. The facility developed provides a forum to local researchers in the field of high energy physics to participate in the LHC experiments and related activities at European particle physics research laboratory (CERN), which is one of the best physics laboratories in the world. It also provides a platform of an emerging computing technology (CT). (author)

CERN looks to the long-term future: might a 100km circular collider follow the LHC around mid-century?

CERN Multimedia

CERN. Geneva

2015-01-01

Particle physics is a long-term field of research: the LHC was originally conceived in the 1980s, but did not start running until 25 years later. An accelerator unlike any other, it is now just at the start of a programme that is set to run for another 20 years. While the LHC programme is already well defined for the next two decades, it is now time to look even further ahead, and so CERN is initiating an exploratory study for a future long-term project centred on a next-generation circular collider with a circumference of 80 to 100 kilometres. A worthy successor to the LHC, whose collision energies will reach 13 TeV in 2015, such an accelerator would allow particle physicists to push the boundaries of knowledge even further. The Future Circular Collider (FCC) programme will focus on studies for a hadron collider, like the LHC, capable of reaching unprecedented energies in the region of 100 TeV. It will also study electron-positron and electron-proton options. Opening with an introduction to the LHC and its...

Prospects for heavy flavor physics at hadron colliders

International Nuclear Information System (INIS)

Butler, J.N.

1997-09-01

The role of hadron colliders in the observation and study of CP violation in B decays is discussed. We show that hadron collider experiments can play a significant role in the early studies of these phenomena and will play an increasingly dominant role as the effort turns towards difficult to measure decays, especially those of the B s meson, and sensitive searches for rare decays and subtle deviations from Standard Model predictions. We conclude with a discussion of the relative merits of hadron collider detectors with 'forward' vs 'central' rapidity coverage

A dedicated LHC collider Beauty experiment for precision measurements of CP-violation. LHC-B letter of intent; TOPICAL

International Nuclear Information System (INIS)

Crosetto, Dario B.

1996-01-01

The LHC-B Collaboration proposes to build a forward collider detector dedicated to the study of CP violation and other rare phenomena in the decays of Beauty particles. The forward geometry results in an average 80 GeV momentum of reconstructed B-mesons and, with multiple, efficient and redundant triggers, yields large event samples. B-hadron decay products are efficiently identified by Ring-Imaging Cerenkov Counters, rendering a wide range of multi-particle final states accessible and providing precise measurements of all angles,(alpha),(beta) and(gamma) of the unitarity triangle. The LHC-B microvertex detector capabilities facilitate multi-vertex event reconstruction and proper-time measurements with an expected few-percent uncertainty, permitting measurements of B(sub s)-mixing well beyond the largest conceivable values of x(sub S). LHC-B would be fully operational at the startup of LHC and requires only a modest luminosity to reveal its full performance potential

High Luminosity Large Hadron Collider A description for the European Strategy Preparatory Group

CERN Document Server

Rossi, L

2012-01-01

The Large Hadron Collider (LHC) is the largest scientific instrument ever built. It has been exploring the new energy frontier since 2009, gathering a global user community of 7,000 scientists. It will remain the most powerful accelerator in the world for at least two decades, and its full exploitation is the highest priority in the European Strategy for Particle Physics, adopted by the CERN Council and integrated into the ESFRI Roadmap. To extend its discovery potential, the LHC will need a major upgrade around 2020 to increase its luminosity (rate of collisions) by a factor of 10 beyond its design value. As a highly complex and optimized machine, such an upgrade of the LHC must be carefully studied and requires about 10 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 13 tesla superconducting magnets, very compact and ultra-precise superconduc...

QCD and Jets at Hadron Colliders

CERN Document Server

Sapeta, Sebastian

2016-01-01

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

The application of the Monte Carlo code FLUKA in radiation protection studies for the large hadron collider

International Nuclear Information System (INIS)

Battistoni, Giuseppe; Broggi, Francesco; Brugger, Markus

2010-01-01

The multi-purpose particle interaction and transport code FLUKA is integral part of all radiation protection studies for the design and operation of the Large Hadron Collider (LHC) at CERN. It is one of the very few codes available for this type of calculations which is capable to calculate in one and the same simulation proton-proton and heavy ion collisions at LHC energies as well as the entire hadronic and electromagnetic particle cascade initiated by secondary particles in detectors and beam-line components from TeV energies down to energies of thermal neutrons. The present paper reviews these capabilities of FLUKA in giving details of relevant physics models along with examples of radiation protection studies for the LHC such as shielding studies for underground areas occupied by personnel during LHC operation and the simulation of induced radioactivity around beam loss points. Integral part of the FLUKA development is a careful benchmarking of specific models as well as the code performance in complex, real life applications which is demonstrated with examples of studies relevant to radiation protection at the LHC. (author)

Beam dynamics aspects of crab cavities in the CERN Large Hadron Collider

CERN Document Server

Sun, Y P; Barranco, J; Tomás, R; Weiler, T; Zimmermann, F; Calaga, R; Morita, A

2009-01-01

Modern colliders bring into collision a large number of bunches to achieve a high luminosity. The long-range beam-beam effects arising from parasitic encounters at such colliders are mitigated by introducing a crossing angle. Under these conditions, crab cavities (CC) can be used to restore effective head-on collisions and thereby to increase the geometric luminosity. Such crab cavities have been proposed for both linear and circular colliders. The crab cavities are rf cavities operated in a transverse dipole mode, which imparts on the beam particles a transverse kick that varies with the longitudinal position along the bunch. The use of crab cavities in the Large Hadron Collider (LHC) may not only raise the luminosity, but it could also complicate the beam dynamics, e.g., crab cavities might not only cancel synchrobetatron resonances excited by the crossing angle but they could also excite new ones, they could reduce the dynamic aperture for off-momentum particles, they could influence the aperture and orbit...

Heavy leptons at hadron colliders

International Nuclear Information System (INIS)

Ohnemus, J.E.

1987-01-01

The recent advent of high energy hadron colliders capable of producing weak bosons has opened new vistas for particle physics research, including the search for a possible fourth generation heavy charged lepton, which is the primary topic of the thesis. Signals for identifying a new heavy lepton have been calculated and compared to Standard Model backgrounds. Results are presented for signals at the CERN collider, the Fermilab collider, and the proposed Superconducting Supercollider

Lecture | CERN prepares its long-term future: a 100-km circular collider to follow the LHC? | CERN Globe | 11 March

CERN Multimedia

2015-01-01

Particle physics is a long-term field of research: the LHC was originally conceived in the 1980s, but did not start running until 25 years later. An accelerator unlike any other, it is now just at the start of a programme that is set to run for another 20 years.   Frédérick Bordry. While the LHC programme is already well defined for the next two decades, it is now time to look even further ahead, and so CERN is initiating an exploratory study for a future long-term project centred on a next-generation circular collider with a circumference of 80 to 100 kilometres. A worthy successor to the LHC, whose collision energies will reach 13 TeV in 2015, such an accelerator would allow particle physicists to push the boundaries of knowledge even further. The Future Circular Collider (FCC) programme will focus especially on studies for a hadron collider, like the LHC, capable of reaching unprecedented energies in the region of 100 TeV. Opening with an introduction to the LHC and...

From the LHC to Future Colliders

DEFF Research Database (Denmark)

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

2010-01-01

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 of integrated luminosity, of the proposed sLHC luminosity up...

The fast tracker processor for hadronic collider triggers

CERN Document Server

Annovi, A; Bardi, A; Carosi, R; Dell'Orso, Mauro; D'Onofrio, M; Giannetti, P; Iannaccone, G; Morsani, F; Pietri, M; Varotto, G

2000-01-01

Perspective for precise and fast track reconstruction in future hadronic collider experiments are addressed. We discuss the feasibility of a pipelined highly parallelized processor dedicated to the implementation of a very fast algorithm. The algorithm is based on the use of a large bank of pre-stored combinations of trajectory points (patterns) for extremely complex tracking systems. The CMS experiment at LHC is used as a benchmark. Tracking data from the events selected by the level-1 trigger are sorted and filtered by the Fast Tracker processor at a rate of 100 kHz. This data organization allows the level-2 trigger logic to reconstruct full resolution traces with transverse momentum above few GeV and search secondary vertexes within typical level-2 times. 15 Refs.

Precision Muon Tracking Detectors for High-Energy Hadron Colliders

CERN Document Server

Gadow, Philipp; Kroha, Hubert; Richter, Robert

2016-01-01

Small-diameter muon drift tube (sMDT) chambers with 15 mm tube diameter are a cost-effective technology for high-precision muon tracking over large areas at high background rates as expected at future high-energy hadron colliders including HL-LHC. The chamber design and construction procedures have been optimized for mass production and provide sense wire positioning accuracy of better than 10 ?m. The rate capability of the sMDT chambers has been extensively tested at the CERN Gamma Irradiation Facility. It exceeds the one of the ATLAS muon drift tube (MDT) chambers, which are operated at unprecedentedly high background rates of neutrons and gamma-rays, by an order of magnitude, which is sufficient for almost the whole muon detector acceptance at FCC-hh at maximum luminosity. sMDT operational and construction experience exists from ATLAS muon spectrometer upgrades which are in progress or under preparation for LHC Phase 1 and 2.

First electron-cloud studies at the Large Hadron Collider

CERN Document Server

Dominguez, O; Arduini, G; Metral, E; Rumolo, G; Zimmermann, F; Maury Cuna, H

2013-01-01

During the beam commissioning of the Large Hadron Collider (LHC) with 150, 75, 50, and 25-ns bunch spacing, important electron-cloud effects, like pressure rise, cryogenic heat load, beam instabilities, or emittance growth, were observed. Methods have been developed to infer different key beam-pipe surface parameters by benchmarking simulations and pressure rise as well as heat-load observations. These methods allow us to monitor the scrubbing process, i.e., the reduction of the secondary emission yield as a function of time, in order to decide on the most appropriate strategies for machine operation. To better understand the influence of electron clouds on the beam dynamics, simulations have been carried out to examine both the coherent and the incoherent effects on the beam. In this paper we present the methodology and first results for the scrubbing monitoring process at the LHC. We also review simulated instability thresholds and tune footprints for beams of different emittance, interacting with an electr...

Modeling of random geometric errors in superconducting magnets with applications to the CERN Large Hadron Collider

Directory of Open Access Journals (Sweden)

P. Ferracin

2000-12-01

Full Text Available Estimates of random field-shape errors induced by cable mispositioning in superconducting magnets are presented and specific applications to the Large Hadron Collider (LHC main dipoles and quadrupoles are extensively discussed. Numerical simulations obtained with Monte Carlo methods are compared to analytic estimates and are used to interpret the experimental data for the LHC dipole and quadrupole prototypes. The proposed approach can predict the effect of magnet tolerances on geometric components of random field-shape errors, and it is a useful tool to monitor the obtained tolerances during magnet production.

Transverse and Longitudinal Beam Collimation in a High-Energy Proton Collider (LHC)

CERN Document Server

Catalan-Lasheras, N

1998-01-01

In the Large Hadron Collider (LHC), particles from the beam halo might potentially impinge on the vacuum chamber, effecting harmful transitions of the superconducting magnets ("quenches"). This can be prevented by the collimation system which confines the particle losses to special, non superconducting sections of the machine. Due to the high energy and intensity of the LHC, any removal system must attain an unprecedented efficiency. The cleaning system was designed on the basis of purely geometric and optical models which neglect non linear effects and assume perfectly absorbing materials. In a second step, true scattering in matter is considered. A series of machine developments (MD) were carried out in 1996-7 with the principal aim of validating the design assumptions. A collimation system comparable to that of the LHC was employed. The predictions of the numerical model used to compute the LHC collimation system efficiency were compared with the data acquired during the measurement sessions. The experimen...

Intensity issues and machine protection of the HE-LHC

OpenAIRE

Assmann, R.

2011-01-01

The HE-LHC study investigates the possibilities for upgrading the beam energy of the Large Hadron Collider CERN from 7 TeV to 16.5 TeV. This paper presents a preliminary investigation of intensity issues and machine protection for the HE-LHC. The HE-LHC study investigates the possibilities for upgrading the beam energy of the Large Hadron Collider CERN from 7 TeV to 16.5 TeV. This paper presents a preliminary investigation of intensity issues and machine protection for the HE-LHC.

Study of jet production in ALICE experiment at LHC collider

CERN Document Server

Jangal, Swensy

The jet is one of the probes allowing testing strong interaction theory predictions, QCD, and to extract physical properties from a particular state of nuclear matter : Quark Gluon Plasma (QGP). This PhD work is aimed to show ALICE capacities to measure jets coming from collisions produced at the Large Hadron Collider (LHC). The detection of particles constituting jets, their association with reconstruction algorithms and the construction of observables such as jet pT spectrum of Hump-Backed Plateau is a hard work. We detail these different steps from simulation allowing to estimate jet rates we could expect for our analysis and to evaluate the impact of experimental measure on final observables. We finally present pT spectrum and Hump-Backed Plateau from first p+p collisions at LHC to whom mean corrections have been applied.

The Compact Muon Solenoid Experiment at the Large Hadron Collider The Compact Muon Solenoid Experiment at the Large Hadron Collider

Directory of Open Access Journals (Sweden)

David Delepine

2012-02-01

Full Text Available The Compact Muon Solenoid experiment at the CERN Large Hadron Collider will study protonproton collisions at unprecedented energies and luminosities. In this article we providefi rst a brief general introduction to particle physics. We then explain what CERN is. Thenwe describe the Large Hadron Collider at CERN, the most powerful particle acceleratorever built. Finally we describe the Compact Muon Solenoid experiment, its physics goals,construction details, and current status.El experimento Compact Muon Solenoid en el Large Hadron Collider del CERN estudiarácolisiones protón protón a energías y luminosidades sin precedente. En este artículo presentamos primero una breve introducción general a la física de partículas. Despuésexplicamos lo que es el CERN. Luego describimos el Large Hadron Collider, el más potente acelerador de partículas construido por el hombre, en el CERN. Finalmente describimos el experimento Compact Muon Solenoid, sus objetivos en física, los detalles de su construcción,y su situación presente.

Controls for the CERN large hadron collider (LHC)

International Nuclear Information System (INIS)

Kissler, K.H.; Perriollat, F.; Rabany, M.; Shering, G.

1992-01-01

CERN's planned large superconducting collider project presents several new challenges to the Control System. These are discussed along with current thinking as to how they can be met. The high field superconducting magnets are subject to 'persistent currents' which will require real time measurements and control using a mathematical model on a 2-10 second time interval. This may be realized using direct links, multiplexed using TDM, between the field equipment and central servers. Quench control and avoidance will make new demands on speed of response, reliability and surveillance. The integration of large quantities of industrially controlled equipment will be important. Much of the controls will be in common with LEP so a seamless integration of LHC and LEP controls will be sought. A very large amount of new high-tech equipment will have to be tested, assembled and installed in the LEP tunnel in a short time. The manpower and cost constrains will be much tighter than previously. New approaches will have to be found to solve many of these problems, with the additional constraint of integrating them into an existing frame work. (author)

Forward-backward asymmetries of lepton pairs in events with a large-transverse-momentum jet at hadron colliders

International Nuclear Information System (INIS)

Aguila, F. del; Ametller, Ll.; Talavera, P.

2002-01-01

We discuss forward-backward charge asymmetries for lepton-pair production in association with a large-transverse-momentum jet at hadron colliders. The lepton charge asymmetry relative to the jet direction A FB j gives a new determination of the effective weak mixing angle sin 2 θ eff lept (M Z 2 ) with a statistical precision after cuts of ∼10 -3 (8x10 -3 ) at LHC (Tevatron). This is to be compared with the current uncertainty at LEP and SLD from the asymmetries alone, 2x10 -4 . The identification of b jets also allows for the measurement of the bottom-quark-Z asymmetry A FB b at hadron colliders, the resulting statistical precision for sin 2 θ eff lept (M Z 2 ) being ∼9x10 -4 (2x10 -2 at Tevatron), also lower than the reported precision at e + e - colliders, 3x10 -4

Jet-hadron correlations relative to the event plane in Pb--Pb collisions at the LHC in ALICE

CERN Document Server

Mazer, Joel

In relativistic heavy ion collisions at the Large Hadron Collider (LHC), a hot, dense and strongly interacting medium known as the Quark Gluon Plasma (QGP) is produced. Quarks and gluons from incoming nuclei collide to produce partons at high momenta early in the collisions. By fragmenting into collimated sprays of hadrons, these partons form 'jets'. Within the framework of perturbative Quantum Chromodynamics (pQCD), jet production is well understood in pp collisions. We can use jets measured in pp interactions as a baseline reference for comparing to heavy ion collision systems to detect and study jet quenching. The jet quenching mechanism can be studied through the angular correlations of trigger jets with charged hadrons and is examined in transverse momentum bins of the trigger jets, transverse momentum bins of the associated hadrons, and studied as a function of collision centrality. A highly robust and precise background subtraction method is used in this analysis to remove the complex, flow domin...

Advanced superconducting technology for global science: The Large Hadron Collider at CERN

International Nuclear Information System (INIS)

Lebrun, Ph.

2002-01-01

The Large Hadron Collider (LHC), presently in construction at CERN, the European Organization for Nuclear Research near Geneva (Switzerland), will be, upon its completion in 2005 and for the next twenty years, the most advanced research instrument of the world's high-energy physics community, providing access to the energy frontier above 1 TeV per elementary constituent. Re-using the 26.7-km circumference tunnel and infrastructure of the past LEP electron-positon collider, operated until 2000, the LHC will make use of advanced superconducting technology-high-field Nb-Ti superconducting magnets operated in superfluid helium and a cryogenic ultra-high vacuum system-to bring into collision intense beams of protons and ions at unprecedented values of center-of-mass energy and luminosity (14 TeV and 10 34 cm -2 ·s -1 , respectively with protons). After some ten years of focussed R and D, the LHC components are presently series-built in industry and procured through world-wide collaboration. After briefly recalling the physics goals, performance challenges and design choices of the machine, we describe its major technical systems, with particular emphasis on relevant advances in the key technologies of superconductivity and cryogenics, and report on its construction progress

Large Hadron Collider manual

CERN Document Server

Lavender, Gemma

2018-01-01

What is the universe made of? How did it start? This Manual tells the story of how physicists are seeking answers to these questions using the world’s largest particle smasher – the Large Hadron Collider – at the CERN laboratory on the Franco-Swiss border. Beginning with the first tentative steps taken to build the machine, the digestible text, supported by color photographs of the hardware involved, along with annotated schematic diagrams of the physics experiments, covers the particle accelerator’s greatest discoveries – from both the perspective of the writer and the scientists who work there. The Large Hadron Collider Manual is a full, comprehensive guide to the most famous, record-breaking physics experiment in the world, which continues to capture the public imagination as it provides new insight into the fundamental laws of nature.

Forward-central jet correlations at the Large Hadron Collider

International Nuclear Information System (INIS)

Deak, M.; Hautmann, F.; Jung, H.; Antwerpen Univ.; Kutak, K.

2010-12-01

For high-p T forward processes at the Large Hadron Collider (LHC), QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. The theoretical framework to resum consistently both kinds of logarithmic corrections to higher orders in perturbation theory is based on QCD high-energy factorization. We present numerical Monte Carlo applications of this method to final-state observables associated with production of one forward and one central jet. By computing jet correlations in rapidity and azimuth, we analyze the role of corrections to the parton-showering chain from large-angle gluon radiation, and discuss this in relationship with Monte Carlo results modeling interactions due to multiple parton chains. (orig.)

Top quark studies at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

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

1997-01-01

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

Top quark studies at hadron colliders

International Nuclear Information System (INIS)

Sinervo, P.K.

1997-01-01

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

Top quark studies at hadron colliders

International Nuclear Information System (INIS)

Sinervo, P.K.

1996-08-01

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

Hadron collider physics

Energy Technology Data Exchange (ETDEWEB)

Pondrom, L.

1991-10-03

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

Hadron collider physics

International Nuclear Information System (INIS)

Pondrom, L.

1991-01-01

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

Advances in elementary particle physics with applied superconductivity. Contribution of superconducting technology to CERN large hadron collider accelerator

International Nuclear Information System (INIS)

Yamamoto, Akira

2011-01-01

The construction of the Large Hadron Collider (LHC) was started in 1994 and completed in 2008. The LHC consists of more than seven thousand superconducting magnets and cavities, which play an essential role in elementary particle physics and its energy frontier. Since 2010, physics experiments at the new energy frontier have been carried out to investigate the history and elementary particle phenomena in the early universe. The superconducting technology applied in the energy frontier physics experiments is briefly introduced. (author)

Beam-related machine protection for the CERN Large Hadron Collider experiments

Directory of Open Access Journals (Sweden)

R. B. Appleby

2010-06-01

Full Text Available The Large Hadron Collider at CERN, Geneva stores 360 MJ per beam of protons at the top machine energy. This amount of energy storage presents a considerable challenge to the machine protection systems designed to protect both the machine and the six LHC experiments. This paper provides an overview of the machine protection systems relevant to the protection of the experiments, and demonstrates their operation and level of protection through a series of injection and stored beam failure scenarios. We conclude that the systems provide sufficient coverage for the protection of the experiments as far as reasonably possible.

Resummation for supersymmetric particle production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Brensing, Silja Christine

2011-05-10

The search for supersymmetry is among the most important tasks at current and future colliders. Especially the production of coloured supersymmetric particles would occur copiously in hadronic collisions. Since these production processes are of high relevance for experimental searches accurate theoretical predictions are needed. Higher-order corrections in quantum chromodynamics (QCD) to these processes are dominated by large logarithmic terms due to the emission of soft gluons from initial-state and final-state particles. A systematic treatment of these logarithms to all orders in perturbation theory is provided by resummation methods. We perform the resummation of soft gluons at next-to-leading-logarithmic (NLL) accuracy for all possible production processes in the framework of the Minimal Supersymmetric Standard Model. In particular we consider pair production processes of mass-degenerate light-flavour squarks and gluinos as well as the pair production of top squarks and non-mass-degenerate bottom squarks. We present analytical results for all considered processes including the soft anomalous dimensions. Moreover numerical predictions for total cross sections and transverse-momentum distributions for both the Large Hadron Collider (LHC) and the Tevatron are presented. We provide an estimate of the theoretical uncertainty due to scale variation and the parton distribution functions. The inclusion of NLL corrections leads to a considerable reduction of the theoretical uncertainty due to scale variation and to an enhancement of the next-to-leading order (NLO) cross section predictions. The size of the soft-gluon corrections and the reduction in the scale uncertainty are most significant for processes involving gluino production. At the LHC, where the sensitivity to squark and gluino masses ranges up to 3 TeV, the corrections due to NLL resummation over and above the NLO predictions can be as high as 35 % in the case of gluino-pair production, whereas at the

Electron reconstruction and electroweak processes as tools to achieve precision measurements at a hadron collider: From CDF to CMS

Energy Technology Data Exchange (ETDEWEB)

Giolo-Nicollerat, Anne-Sylvie [Univ. of Lausanne (Switzerland)

2004-01-01

Precision measurements are an important aspect of hadron colliders physics program. This thesis describes a method, together with a first application, of how to achieve and use precision measurements at the LHC. The idea is to use refernce processes to control the detector systematics and to constrain the theoretical predictions.

The fast tracker processor for hadron collider triggers

CERN Document Server

Annovi, A; Bardi, A; Carosi, R; Dell'Orso, Mauro; D'Onofrio, M; Giannetti, P; Iannaccone, G; Morsani, E; Pietri, M; Varotto, G

2001-01-01

Perspectives for precise and fast track reconstruction in future hadron collider experiments are addressed. We discuss the feasibility of a pipelined highly parallel processor dedicated to the implementation of a very fast tracking algorithm. The algorithm is based on the use of a large bank of pre-stored combinations of trajectory points, called patterns, for extremely complex tracking systems. The CMS experiment at LHC is used as a benchmark. Tracking data from the events selected by the level-1 trigger are sorted and filtered by the Fast Tracker processor at an input rate of 100 kHz. This data organization allows the level-2 trigger logic to reconstruct full resolution tracks with transverse momentum above a few GeV and search for secondary vertices within typical level-2 times. (15 refs).

Production of light flavor hadrons and anti-nuclei at the LHC

CERN Document Server

Kalweit, Alexander

With the recording of the first collisions of the Large Hadron Collider (LHC) in November 2009, a new era in the domain of high energy and relativistic heavy-ion physics has started. As one of the early observables which can be addressed, the measurement of light quark flavor production is presented in this thesis. Hadrons that consist only of u, d, and s quarks constitute the majority of the produced particles in pp and Pb–Pb collisions. Their measurement forms the basis for a detailed understanding of the collision and for the answer of the question if hadronic matter undergoes a phase transition to the deconfined quark-gluon plasma at high temperatures. The basics of ultra-relativistic heavy- ion physics are briefly introduced in the first chapter followed by a short description of the ALICE experiment. A particular focus is put on the unique particle identification (PID) capabilities as they provide the basis of the measurements which are presented in the following chapters. The particle identification ...

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

International Nuclear Information System (INIS)

KING, B.J.

2000-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

KING,B.J.

2000-05-05

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

Beam losses from ultra-peripheral nuclear collisions between $^{208}$Pb$^{82+}$ ions in the Large Hadron Collider and their alleviation

CERN Document Server

Bruce, R.; Jowett, J.M.; Bocian, D.; CERN. Geneva. BE Department

2009-01-01

Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC) at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte-Carlo shower simulation and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of Pb ion operation in the LHC, with focus on the ALICE interaction region, and show that the expected heat load during nominal Pb operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.

Beam losses from ultraperipheral nuclear collisions between ^{208}Pb^{82+} ions in the Large Hadron Collider and their alleviation

Directory of Open Access Journals (Sweden)

R. Bruce

2009-07-01

Full Text Available Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte Carlo shower simulation, and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of ^{208}Pb^{82+} ion operation in the LHC, with focus on the ALICE interaction region, and show that the expected heat load during nominal ^{208}Pb^{82+} operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.

Upgrade of the ATLAS hadronic Tile Calorimeter for the High luminosity LHC

CERN Document Server

Rodriguez Bosca, Sergi; The ATLAS collaboration

2017-01-01

The Tile Calorimeter is the hadronic calorimeter covering the central region of the ATLAS detector at the Large Hadron Collider. It is a scintillator-steel sampling calorimeter read out via wavelength shifting fibers coupled to photomultiplier tubes (PMT). The PMT signals are digitized and stored on detector until a trigger is received. The High-Luminosity phase of LHC (HL-LHC) expected to begin in year 2026 requires new electronics to meet the requirements of a 1 MHz trigger, higher ambient radiation, and for better performance under higher pileup. All the TileCal on- and off-detector electronics will be replaced during the shutdown of 2024-2025. PMT signals from every TileCal cell will be digitized and sent directly to the back-end electronics, where the signals are reconstructed, stored, and sent to the first level of trigger at a rate of 40 MHz. This will provide better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Change...

Upgrade of the ATLAS hadronic Tile Calorimeter for the High luminosity LHC

CERN Document Server

Rodriguez Bosca, Sergi; The ATLAS collaboration

2017-01-01

The Tile Calorimeter is the hadronic calorimeter covering the central region of the ATLAS detector at the Large Hadron Collider. It is a scintillator-steel sampling calorimeter read out via wavelength shifting fibers coupled to photomultiplier tubes (PMT). The PMT signals are digitized and stored on detector until a trigger is received. The High-Luminosity phase of LHC (HL-LHC)expected to begin in year 2026 requires new electronics to meet the requirements of a 1 MHz trigger, higher ambient radiation, and for better performance under higher pileup. All the TileCal on- and off-detector electronics will be replaced during the shutdown of 2024-2025. PMT signals from every TileCal cell will be digitized and sent directly to the back-end electronics, where the signals are reconstructed, stored, and sent to the first level of trigger at a rate of 40 MHz. This will provide better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Changes...

Physics Interplay of the LHC and the ILC

Energy Technology Data Exchange (ETDEWEB)

Weiglein, G.

2004-12-17

Physics at the Large Hadron Collider (LHC) and the International e{sup +}e{sup -} Linear Collider (ILC)will be complementary in many respects, as has been demonstrated at previous generations of hadron and lepton colliders. This report addresses the possible interplay between the LHC and ILC in testing the Standard Model and in discovering and determining the origin of new physics. Mutual benefits for the physics programme at both machines can occur both at the level of a combined interpretation of Hadron Collider and Linear Collider data and at the level of combined analyses of the data, where results obtained at one machine can directly influence the way analyses are carried out at the other machine. Topics under study comprise the physics of weak and strong electroweak symmetry breaking, supersymmetric models, new gauge theories, models with extra dimensions, and electroweak and QCD precision physics. The status of the work that has been carried out within the LHC/LC Study Group so far is summarized in this report. Possible topics for future studies are outlined.

In the loop Large Hadron Collider project - UK engineering firms

CERN Document Server

Wilks, N

2004-01-01

This paper presents the latest measures being taken to boost the level of UK engineering firms' involvement in research at CERN (Centre for Nuclear Research), including its 27 km circular Large Hadron Collider (LHC) project. Virtually all of the components on this complex project have had to be custom-made, usually in the form of collaboration. It is part of these collaborations that some UK firms have proved they can shine. However, despite the proven capabilities, the financial return continues to be less than the government's funding. Each of the 20 CERN member states provides funds in proportion to its GDP and the UK is the second largest financial contributor. UK firms become price-competitive where a contract calls for a degree of customisation or product development, project management and tight quality control. Development of the Particle Physics Grid, for dissemination and analysis of data from the LHC, continues to provide major supply opportunities for UK manufacturers.

Angular distribution of Drell-Yan process at hadron colliders to NLO-QCD in models of TeV scale gravity

International Nuclear Information System (INIS)

Mathews, Prakash; Ravindran, V.

2006-01-01

In TeV scale gravity models, for dilepton production at hadron colliders, we present the NLO-QCD corrections for the double differential cross section in the invariant mass and scattering angle. For both ADD and RS models, the quantitative impact of QCD corrections for extra dimension searches at LHC and Tevatron are investigated. We present the K-factors for both ADD and RS models at LHC and Tevatron. Inclusion of QCD corrections to NLO stabilises the cross section with respect to scale variations

Forward-central jet correlations at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Deak, M. [Univ. Autonoma de Madrid, Cantoblanco (Spain). Inst. de Fisica Teorica UAM/CSIC; Hautmann, F. [Oxford Univ. (United Kingdom). Theoretical Physics Dept.; Jung, H. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Antwerpen Univ. (Belgium). Elementaire Deeltjes Fysics; Kutak, K. [Antwerpen Univ. (Belgium). Elementaire Deeltjes Fysics

2010-12-15

For high-p{sub T} forward processes at the Large Hadron Collider (LHC), QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. The theoretical framework to resum consistently both kinds of logarithmic corrections to higher orders in perturbation theory is based on QCD high-energy factorization. We present numerical Monte Carlo applications of this method to final-state observables associated with production of one forward and one central jet. By computing jet correlations in rapidity and azimuth, we analyze the role of corrections to the parton-showering chain from large-angle gluon radiation, and discuss this in relationship with Monte Carlo results modeling interactions due to multiple parton chains. (orig.)

Effective models of new physics at the Large Hadron Collider

International Nuclear Information System (INIS)

Llodra-Perez, J.

2011-07-01

With the start of the Large Hadron Collider runs, in 2010, particle physicists will be soon able to have a better understanding of the electroweak symmetry breaking. They might also answer to many experimental and theoretical open questions raised by the Standard Model. Surfing on this really favorable situation, we will first present in this thesis a highly model-independent parametrization in order to characterize the new physics effects on mechanisms of production and decay of the Higgs boson. This original tool will be easily and directly usable in data analysis of CMS and ATLAS, the huge generalist experiments of LHC. It will help indeed to exclude or validate significantly some new theories beyond the Standard Model. In another approach, based on model-building, we considered a scenario of new physics, where the Standard Model fields can propagate in a flat six-dimensional space. The new spatial extra-dimensions will be compactified on a Real Projective Plane. This orbifold is the unique six-dimensional geometry which possesses chiral fermions and a natural Dark Matter candidate. The scalar photon, which is the lightest particle of the first Kaluza-Klein tier, is stabilized by a symmetry relic of the six dimension Lorentz invariance. Using the current constraints from cosmological observations and our first analytical calculation, we derived a characteristic mass range around few hundred GeV for the Kaluza-Klein scalar photon. Therefore the new states of our Universal Extra-Dimension model are light enough to be produced through clear signatures at the Large Hadron Collider. So we used a more sophisticated analysis of particle mass spectrum and couplings, including radiative corrections at one-loop, in order to establish our first predictions and constraints on the expected LHC phenomenology. (author)

The super-LHC

CERN Document Server

Mangano, Michelangelo L

2010-01-01

We review here the prospects of a long-term upgrade programme for the Large Hadron Collider (LHC), CERN laboratory's new proton-proton collider. The super-LHC, which is currently under evaluation and design, is expected to deliver of the order of ten times the statistics of the LHC. In addition to a non-technical summary of the principal physics arguments for the upgrade, I present a pedagogical introduction to the technological challenges on the accelerator and experimental fronts, and a review of the current status of the planning.

Superconductive technologies for the Large Hadron collider at CERN

CERN Document Server

Rossi, L

2000-01-01

The Large Hadron Collider (LHC) project is the largest plant based on superconductivity and cryogenics: 27 km of tunnel filled with superconducting magnets and other equipment that will be kept at 1.9 K. The dipole magnets have to generate a minimum magnetic field of 8.3 T to allow collisions of proton beams at an energy of 14 TeV in the centre of mass. The construction of LHC started in 1997 at CERN in Geneva and required 10 years of research and development on fine- filament NbTi superconducting wires and cables, on magnet technology and on He-II refrigerators. In particular the project needs the production of about 1000 tons of high-homogeneity NbTi with current densities of more than 2000 A mm/sup -2/ at 9 T and 1.9 K, with tight control also of all other cable properties such as magnetization, interstrand resistance and copper resistivity. The paper describes the main dipole magnets and reviews the most significant steps in the research and development, focusing on the issues related to the conductor, to...

Cryogenic studies for the proposed CERN large hadron electron collider (LHEC)

Science.gov (United States)

Haug, F.; LHeC Study Team, The

2012-06-01

The LHeC (Large Hadron electron Collider) is a proposed future colliding beam facility for lepton-nucleon scattering particle physics at CERN. A new 60 GeV electron accelerator will be added to the existing 27 km circumference 7 TeV LHC for collisions of electrons with protons and heavy ions. Two basic design options are being pursued. The first is a circular accelerator housed in the existing LHC tunnel which is referred to as the "Ring-Ring" version. Low field normal conducting magnets guide the particle beam while superconducting (SC) RF cavities cooled to 2 K are installed at two opposite locations at the LHC tunnel to accelerate the beams. For this version in addition a 10 GeV re-circulating SC injector will be installed. In total four refrigerators with cooling capacities between 1.2 kW and 3 kW @ 4.5 K are needed. The second option, referred to as the "Linac-Ring" version consists of a race-track re-circulating energyrecovery type machine with two 1 km long straight acceleration sections. The 944 high field 2 K SC cavities dissipate 30 kW at CW operation. Eight 10 kW @ 4.5 K refrigerators are proposed. The particle detector contains a combined SC solenoid and dipole forming the cold mass and an independent liquid argon calorimeter. Cooling is done with two individual small sized cryoplants; a 4.5 K helium, and a 87 K liquid nitrogen plant.

Quench protection diodes for the large hadron collider LHC at CERN

International Nuclear Information System (INIS)

Hagedorn, D.; Naegele, W.

1992-01-01

For the quench protection of the main ring dipole and quadrupole magnets for the proposed Large Hadron Collider at CERN two lines of approach have been pursued for the realization of a suitable high current by-pass element and liquid helium temperature. Two commercially available diodes of the HERA type connected in parallel can easily meet the requirements if a sufficient good current sharing is imposed by current balancing elements. Design criteria for these current balancing elements are derived from individual diode characteristics. Single diode elements of thin base region, newly developed in industry, have been successfully tested. The results are promising and, if the diodes can be made with reproducible characteristics, they will provide the preferred solution especially in view of radiation hardness

CP violation in supersymmetry, Higgs sector and large hadron collider

International Nuclear Information System (INIS)

Godbole, Rohini M.

2006-01-01

In this talk I discuss some aspects of CP violation (CPV) in supersymmetry (SUSY) as well as in the Higgs sector. Further, I discuss ways in which these may be probed at hadronic colliders. In particular I will point out the ways in which studies in the χ ∼± , χ 2 ∼0 sector at Tevatron may be used to provide information on this and how the search can be extended to the LHC. I will then follow this by a discussion of the CP mixing induced in the Higgs sector due to the above-mentioned CPV in the soft SUSY breaking parameters and its effects on the Higgs phenomenology at the LHC. I would then point out some interesting aspects of the phenomenology of a moderately light charged Higgs boson, consistent with the LEP constraints, in this scenario. Decay of such a charged Higgs boson would also allow a probe of a light (≤)50 GeV), CP-violating (CPV) Higgs boson. Such a light neutral Higgs boson might have escaped detection at LEP and could also be missed at the LHC in the usual search channels. (author)

Design study of the large hadron electron collider and a rapid cycling synchrotron as alternative to the PS booster upgrade at CERN

International Nuclear Information System (INIS)

Fitterer, Miriam

2013-01-01

With the Large Hadron Collider (LHC) the exploration of particle physics at center of mass energies at the TeV scale has begun. To extend the discovery potential of the LHC, a major upgrade is foreseen around 2020 of the LHC itself and the LHC injectors - the chain of accelerators preparing the beam for the LHC. One of the injectors - the second one in the chain - is the Proton Synchrotron (PS) Booster. Its performance is currently limited by the space-charge effect, which is the effect of the electromagnetic field of the particle beam on itself. This effect becomes weaker with higher energy, and therefore an energy upgrade of the PS Booster to 2 GeV maximum beam energy is foreseen. As the PS Booster is with its 40 years already an old machine, the construction of a new accelerator, a Rapid Cycling Synchrotron (RCS), to replace the PS Booster has been proposed. In this thesis different options for the beam guidance in the RCS - referred to as lattice and optics - are studied, followed by a more general comparison of different lattices and optics and their performance under consideration of the space-charge effect. To further complement the LHC physics program, also the possibility of deep inelastic lepton-nucleon scattering at the LHC has been suggested, referred to as Large Hadron Electron Collider (LHeC). In this case the proton beam of the LHC collides with the electron beam, which is accelerated in a separate newly built machine. Two options are considered as electron accelerator: a new energy recovery linac - the Linac-Ring option - and the installation of an electron ring in the existing LHC tunnel - the Ring-Ring option. One of the main challenges of the Ring-Ring option is the integration of the electron ring in the current LHC tunnel. A layout, lattice and optics of the electron accelerator is developed in this thesis, which meets the requirements with regard to integration and reaches the beam parameters demanded by the particle physics experiments.

Design study of the large hadron electron collider and a rapid cycling synchrotron as alternative to the PS booster upgrade at CERN

Energy Technology Data Exchange (ETDEWEB)

Fitterer, Miriam

2013-02-22

With the Large Hadron Collider (LHC) the exploration of particle physics at center of mass energies at the TeV scale has begun. To extend the discovery potential of the LHC, a major upgrade is foreseen around 2020 of the LHC itself and the LHC injectors - the chain of accelerators preparing the beam for the LHC. One of the injectors - the second one in the chain - is the Proton Synchrotron (PS) Booster. Its performance is currently limited by the space-charge effect, which is the effect of the electromagnetic field of the particle beam on itself. This effect becomes weaker with higher energy, and therefore an energy upgrade of the PS Booster to 2 GeV maximum beam energy is foreseen. As the PS Booster is with its 40 years already an old machine, the construction of a new accelerator, a Rapid Cycling Synchrotron (RCS), to replace the PS Booster has been proposed. In this thesis different options for the beam guidance in the RCS - referred to as lattice and optics - are studied, followed by a more general comparison of different lattices and optics and their performance under consideration of the space-charge effect. To further complement the LHC physics program, also the possibility of deep inelastic lepton-nucleon scattering at the LHC has been suggested, referred to as Large Hadron Electron Collider (LHeC). In this case the proton beam of the LHC collides with the electron beam, which is accelerated in a separate newly built machine. Two options are considered as electron accelerator: a new energy recovery linac - the Linac-Ring option - and the installation of an electron ring in the existing LHC tunnel - the Ring-Ring option. One of the main challenges of the Ring-Ring option is the integration of the electron ring in the current LHC tunnel. A layout, lattice and optics of the electron accelerator is developed in this thesis, which meets the requirements with regard to integration and reaches the beam parameters demanded by the particle physics experiments.

Industrial Technology for Unprecented Energy and Luminosity The Large Hadron Collider

CERN Document Server

Lebrun, P

2004-01-01

With over 3 billion Swiss francs procurement contracts under execution in industry and the installation of major technical systems in its first 3.3 km sector, the Large Hadron Collider (LHC) construction is now in full swing at CERN, the European Organization for Nuclear Research. The LHC is not only the most challenging particle accelerator, it is also the largest global project ever for a scientific instrument based on advanced technology. Starting from accelerator performance requirements, we recall how these can be met by an appropriate combination of technologies, such as high-field superconducting magnets, superfluid helium cryogenics, power electronics, with particular emphasis on developments required to meet demanding specifications, and industrialization issues which had to be solved for achieving series production of precision components under tight quality assurance and within limited resources. This provides the opportunity for reviewing the production status of the main systems and the progress ...

Electromagnetic Design and Optimization of Directivity of Stripline Beam Position Monitors for the High Luminosity Large Hadron Collider

CERN Document Server

Draskovic, Drasko; Jones, Owain Rhodri; Lefèvre, Thibaut; Wendt, Manfred

2015-01-01

This paper presents the preliminary electromagnetic design of a stripline Beam Position Monitor (BPM) for the High Luminosity program of the Large Hadron Collider (HL-LHC) at CERN. The design is fitted into a new octagonal shielded Beam Screen for the low-beta triplets and is optimized for high directivity. It also includes internal Tungsten absorbers, required to reduce the energy deposition in the superconducting magnets. The achieved broadband directivity in wakefield solver simulations presents significant improvement over the directivity of the current stripline BPMs installed in the LHC.

Collider Physics

OpenAIRE

Zeppenfeld, D.

1999-01-01

These lectures are intended as a pedagogical introduction to physics at $e^+e^-$ and hadron colliders. A selection of processes is used to illustrate the strengths and capabilities of the different machines. The discussion includes $W$ pair production and chargino searches at $e^+e^-$ colliders, Drell-Yan events and the top quark search at the Tevatron, and Higgs searches at the LHC.

Comparison of electric dipole moments and the Large Hadron Collider for probing CP violation in triple boson vertices

CERN Document Server

Jung, Sunghoon

2009-01-01

CP violation from physics beyond the Standard Model may reside in triple boson vertices of the electroweak theory. We review the effective theory description and discuss how CP violating contributions to these vertices might be discerned by electric dipole moments (EDM) or diboson production at the Large Hadron Collider (LHC). Despite triple boson CP violating interactions entering EDMs only at the two-loop level, we find that EDM experiments are generally more powerful than the diboson processes. To give example to these general considerations we perform the comparison between EDMs and collider observables within supersymmetric theories that have heavy sfermions, such that substantive EDMs at the one-loop level are disallowed. EDMs generally remain more powerful probes, and next-generation EDM experiments may surpass even the most optimistic assumptions for LHC sensitivities.

For information - Université de Genève : Accelerator Physics Challenges for the Large Hadron Collider at CERN

CERN Multimedia

Université de Genève

2005-01-01

UNIVERSITE DE GENEVE Faculte des sciences Section de physique - Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet - 1211 GENEVE 4 Tél : (022) 379 62 73 Fax: (022) 379 69 92 Mercredi 16 March SEMINAIRE DE PHYSIQUE CORPUSCULAIRE à 17h00 - Auditoire Stückelberg Accelerator Physics Challenges for the Large Hadron Collider at CERN Prof. Olivier Bruning / CERN The Large Hadron Collider project at CERN will bring the energy frontier of high energy particle physics back to Europe and with it push the accelerator technology into uncharted teritory. The talk presents the LHC project in the context of the past CERN accelerator developments and addresses the main challenges in terms of technology and accelerator physics. Information: http://dpnc.unige.ch/seminaire/annonce.html Organizer: A. Cervera Villanueva

Crystal Ball: On the Future High Energy Colliders

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2015-09-20

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

Physics Opportunities at the Large Hadron Collider

International Nuclear Information System (INIS)

Roeck, Albert de

2006-01-01

In about two years time the LHC is scheduled to deliver its first pp collisions at a centre of mass energy of 14 TeV. The LHC is expected to open up the discovery of new physics at the TeV scale, and give the final answer on the Standard Model Higgs. The LHC will however also be a tool for precision physics. Furthermore LHC is also a pA and AA collider. This report summarizes some of the physics opportunities of the LHC

Photoproduction of vector mesons in proton-proton ultraperipheral collisions at the CERN Large Hadron Collider

Science.gov (United States)

Xie, Ya-Ping; Chen, Xurong

2018-05-01

Photoproduction of vector mesons is computed with dipole model in proton-proton ultraperipheral collisions (UPCs) at the CERN Large Hadron Collider (LHC). The dipole model framework is employed in the calculations of vector mesons production in diffractive processes. Parameters of the bCGC model are refitted with the latest inclusive deep inelastic scattering experimental data. Employing the bCGC model and boosted Gaussian light-cone wave function for vector mesons, we obtain the prediction of rapidity distributions of J/ψ and ψ(2s) mesons in proton-proton ultraperipheral collisions at the LHC. The predictions give a good description of the experimental data of LHCb. Predictions of ϕ and ω mesons are also evaluated in this paper.

Manufacturing and Installation of the Compound Cryogenic Distribution Line for the Large Hadron Collider

CERN Document Server

Riddone,, G; Bouillot, A; Brodzinski, K; Dupont, M; Fathallah, M; Fournel, JL; Gitton, E; Junker, S; Moussavi, H; Parente, C; Riddone, G

2007-01-01

The Large Hadron Collider (LHC) [1] currently under construction at CERN will make use of superconducting magnets operating in superfluid helium below 2 K. A compound cryogenic distribution line (QRL) will feed with helium at different temperatures and pressures the local elementary cooling loops in the cryomagnet strings. Low heat inleak to all temperature levels is essential for the overall LHC cryogenic performance. Following a competitive tendering, CERN adjudicated in 2001 the contract for the series line to Air Liquide (France). This paper recalls the main features of the technical specification and shows the project status. The basic choices and achievements for the industrialization phase of the series production are also presented, as well as the installation issues and status.

Physics at the Large Hadron Collider

CERN Document Server

Mukhopadhyaya, Biswarup; Raychaudhari, Amitava

2009-01-01

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

Probing two-photon decay widths of mesons at energies available at the CERN Large Hadron Collider (LHC)

International Nuclear Information System (INIS)

Bertulani, C. A.

2009-01-01

Meson production cross sections in ultraperipheral relativistic heavy ion collisions at the CERN Large Hadron Collider are revisited. The relevance of meson models and of exotic QCD states is discussed. This study includes states that have not been considered before in the literature.

On measuring the masses of pair-produced semi-invisibly decaying particles at hadron colliders

International Nuclear Information System (INIS)

Tovey, Daniel R.

2008-01-01

A straightforward new technique is introduced which enables measurement at hadron colliders of an analytical combination of the masses of pair-produced semi-invisibly decaying particles and their invisible decay products. The new technique makes use of the invariance under contra-linear Lorentz boosts of a simple combination of the transverse momentum components of the aggregate visible products of each decay chain. In the general case where the invariant masses of the visible decay products are non-zero it is shown that in principle the masses of both the initial particles from the hard scattering and the invisible particles produced in the decay chains can be determined independently. This application is likely to be difficult to realise in practice however due to the contamination of the final state with ISR jets. The technique may be of most use for measurements of SUSY particle masses at the LHC, however the technique should be applicable to any class of hadron collider events in which heavy particles of unknown mass are pair-produced and decay to semi-invisible final states

The hunt for new physics at the Large Hadron Collider

International Nuclear Information System (INIS)

AbdusSalam, S.; Adam-Bourdarios, C.; Aguilar-Saavedra, J.A.; Allanach, B.; Altunkaynak, B.; Wagner, C.E.M.

2010-01-01

The Large Hadron Collider presents an unprecedented opportunity to probe the realm of new physics in the TeV region and shed light on some of the core unresolved issues of particle physics. These include the nature of electroweak symmetry breaking, the origin of mass, the possible constituent of cold dark matter, new sources of CP violation needed to explain the baryon excess in the universe, the possible existence of extra gauge groups and extra matter, and importantly the path Nature chooses to resolve the hierarchy problem - is it supersymmetry or extra dimensions. Many models of new physics beyond the standard model contain a hidden sector which can be probed at the LHC. Additionally, the LHC will be a top factory and accurate measurements of the properties of the top and its rare decays will provide a window to new physics. Further, the LHC could shed light on the origin of neutralino masses if the new physics associated with their generation lies in the TeV region. Finally, the LHC is also a laboratory to test the hypothesis of TeV scale strings and D brane models. An overview of these possibilities is presented in the spirit that it will serve as a companion to the Technical Design Reports (TDRs) by the particle detector groups ATLAS and CMS to facilitate the test of the new theoretical ideas at the LHC. Which of these ideas stands the test of the LHC data will govern the course of particle physics in the subsequent decades.

Jet signals for low mass strings at the large hadron collider.

Science.gov (United States)

Anchordoqui, Luis A; Goldberg, Haim; Nawata, Satoshi; Taylor, Tomasz R

2008-05-02

The mass scale M{s} of superstring theory is an arbitrary parameter that can be as low as few TeVs if the Universe contains large extra dimensions. We propose a search for the effects of Regge excitations of fundamental strings at the CERN Large Hadron Collider (LHC), in the process pp-->gamma+jet. The underlying parton process is dominantly the single photon production in gluon fusion, gg-->gammag, with open string states propagating in intermediate channels. If the photon mixes with the gauge boson of the baryon number, which is a common feature of D-brane quivers, the amplitude appears already at the string disk level. It is completely determined by the mixing parameter-and it is otherwise model (compactification) independent. Even for relatively small mixing, 100 fb{-1} of LHC data could probe deviations from standard model physics, at a 5sigma significance, for M{s} as large as 3.3 TeV.

Tevatron-for-LHC Report of the QCD Working Group

Energy Technology Data Exchange (ETDEWEB)

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

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.

The Large Hadron Collider (LHC): The Energy Frontier

Science.gov (United States)

Brianti, Giorgio; Jenni, Peter

The following sections are included: * Introduction * Superconducting Magnets: Powerful, Precise, Plentiful * LHC Cryogenics: Quantum Fluids at Work * Current Leads: High Temperature Superconductors to the Fore * A Pumping Vacuum Chamber: Ultimate Simplicity * Vertex Detectors at LHC: In Search of Beauty * Large Silicon Trackers: Fast, Precise, Efficient * Two Approaches to High Resolution Electromagnetic Calorimetry * Multigap Resistive Plate Chamber: Chronometry of Particles * The LHCb RICH: The Lord of the Cherenkov Rings * Signal Processing: Taming the LHC Data Avalanche * Giant Magnets for Giant Detectors

Quarkonium+{gamma} production in coherent hadron-hadron interactions at LHC energies

Energy Technology Data Exchange (ETDEWEB)

Goncalves, V.P. [Universidade Federal de Pelotas, Instituto de Fisica e Matematica, Caixa Postal 354, Pelotas, RS (Brazil); Machado, M.M. [IF - Farroupilha, Instituto Federal de Educacao, Ciencia e Tecnologia, Sao Borja, RS (Brazil)

2012-11-15

In this paper we study the H+{gamma} (H=J/{Psi} and and upsilon;) production in coherent hadron-hadron interactions at LHC energies. Considering the ultrarelativistic protons as a source of photons, we estimate the {gamma}+p{yields}H+{gamma}+X cross section using the non-relativistic QCD (NRQCD) factorization formalism and considering different sets of values for the matrix elements. Our results for the total p+p{yields}p+H+{gamma}+X cross sections and rapidity distributions at {radical}(s) = 7 and 14 TeV demonstrate that the experimental analysis of the J/{Psi}+{gamma} production at LHC is feasible. (orig.)

Il Collisore LHC (Large Hadron Collider)

CERN Multimedia

Brianti, Giorgio

2004-01-01

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

Extra dimension searches at hadron colliders to next-to-leading ...

Indian Academy of Sciences (India)

The quantitative impact of NLO-QCD corrections for searches of large and warped extra dimensions at hadron colliders are investigated for the Drell-Yan process. The K-factor for various observables at hadron colliders are presented. Factorisation, renormalisation scale dependence and uncertainties due to various parton ...

Development of large-capacity refrigeration at 1.8 K for the Large Hadron Collider at CERN

CERN Document Server

Lebrun, P; Claudet, G

1996-01-01

CERN, the European Laboratory for Particle Physics, is working towards the construction of the Large Hadron Collider (LHC), a high-energy, high-luminosity particle accelerator and collider [1] of 26.7 km circumference, due to start producing frontier physics, by bringing into collision intense proton and ion beams with centre-of-mass energies in the TeV-per-constituent range, at the beginning of the next century. The key technology for achieving this ambitious scientific goal at economically acceptable cost is the use of high-field superconducting magnets using Nb-Ti conductor operating in superfluid helium [2]. To maintain the some 25 km of bending and focusing magnets at their operating temperature of 1.9 K, the LHC cryogenic system will have to produce an unprecedented total refrigeration capacity of about 20 kW at 1.8 K, in eight cryogenic plants distributed around the machine circumference [3]. This has requested the undertaking of an industrial development programme, in the form of a collaboration betwe...

Standard model Higgs physics at colliders

International Nuclear Information System (INIS)

Rosca, A.

2007-01-01

In this report we briefly review the experimental status and prospects to verify the Higgs mechanism of spontaneous symmetry breaking. The focus is on the most relevant aspects of the phenomenology of the Standard Model Higgs boson at current (Tevatron) and future (Large Hadron Collider, LHC and International Linear Collider, ILC) particle colliders. We review the Standard Model searches: searches at the Tevatron, the program planned at the LHC and prospects at the ILC. Emphasis is put on what follows after a candidate discovery at the LHC: the various measurements which are necessary to precisely determine what the properties of this Higgs candidate are. (author)

Physics and Analysis at a Hadron Collider - An Introduction (1/3)

CERN Multimedia

CERN. Geneva

2010-01-01

This is the first lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This first lecture provides a brief introduction to hadron collider physics and collider detector experiments as well as offers some analysis guidelines. The lectures are aimed at graduate students.

Excited quark production at hadron colliders

International Nuclear Information System (INIS)

Baur, U.; Hinchliffe, I.; Zeppenfeld, D.

1987-06-01

Composite models generally predict the existence of excited quark and lepton states. We consider the production and experimental signatures of excited quarks Q* of spin and isospin 1/2 at hadron colliders and estimate the background for those channels which are most promising for Q* identification. Multi-TeV pp-colliders will give access to such particles with masses up to several TeV

Calculations of safe collimator settings and β^{*} at the CERN Large Hadron Collider

Directory of Open Access Journals (Sweden)

R. Bruce

2015-06-01

Full Text Available The first run of the Large Hadron Collider (LHC at CERN was very successful and resulted in important physics discoveries. One way of increasing the luminosity in a collider, which gave a very significant contribution to the LHC performance in the first run and can be used even if the beam intensity cannot be increased, is to decrease the transverse beam size at the interaction points by reducing the optical function β^{*}. However, when doing so, the beam becomes larger in the final focusing system, which could expose its aperture to beam losses. For the LHC, which is designed to store beams with a total energy of 362 MJ, this is critical, since the loss of even a small fraction of the beam could cause a magnet quench or even damage. Therefore, the machine aperture has to be protected by the collimation system. The settings of the collimators constrain the maximum beam size that can be tolerated and therefore impose a lower limit on β^{*}. In this paper, we present calculations to determine safe collimator settings and the resulting limit on β^{*}, based on available aperture and operational stability of the machine. Our model was used to determine the LHC configurations in 2011 and 2012 and it was found that β^{*} could be decreased significantly compared to the conservative model used in 2010. The gain in luminosity resulting from the decreased margins between collimators was more than a factor 2, and a further contribution from the use of realistic aperture estimates based on measurements was almost as large. This has played an essential role in the rapid and successful accumulation of experimental data in the LHC.

Calculations of safe collimator settings and β* at the CERN Large Hadron Collider

Science.gov (United States)

Bruce, R.; Assmann, R. W.; Redaelli, S.

2015-06-01

The first run of the Large Hadron Collider (LHC) at CERN was very successful and resulted in important physics discoveries. One way of increasing the luminosity in a collider, which gave a very significant contribution to the LHC performance in the first run and can be used even if the beam intensity cannot be increased, is to decrease the transverse beam size at the interaction points by reducing the optical function β*. However, when doing so, the beam becomes larger in the final focusing system, which could expose its aperture to beam losses. For the LHC, which is designed to store beams with a total energy of 362 MJ, this is critical, since the loss of even a small fraction of the beam could cause a magnet quench or even damage. Therefore, the machine aperture has to be protected by the collimation system. The settings of the collimators constrain the maximum beam size that can be tolerated and therefore impose a lower limit on β*. In this paper, we present calculations to determine safe collimator settings and the resulting limit on β*, based on available aperture and operational stability of the machine. Our model was used to determine the LHC configurations in 2011 and 2012 and it was found that β* could be decreased significantly compared to the conservative model used in 2010. The gain in luminosity resulting from the decreased margins between collimators was more than a factor 2, and a further contribution from the use of realistic aperture estimates based on measurements was almost as large. This has played an essential role in the rapid and successful accumulation of experimental data in the LHC.

Development of an abort gap monitor for the large hadron collider

International Nuclear Information System (INIS)

Beche, J.-F.; Byrd, J.; De Santis, S.; Placidi, M.; Turner, W.; Zolotorev, M.

2004-01-01

The Large Hadron Collider (LHC), presently under construction at CERN, requires monitoring the parasitic charge in the 3.3ms long gap in the machine fill structure. This gap, referred to as the abort gap, corresponds to the raise time of the abort kickers magnets. Any circulating particle present in the abort gap at the time of the kickers firing is lost inside the ring, rather than in the beam dump, and can potentially damage a number of the LHC components. CERN specifications indicate a linear density of 6 x 106 protons over a 100 ns interval as the maximum charge safely allowed to accumulate in the abort gap at 7 TeV. We present a study of an abort gap monitor, based on a photomultiplier tube with a gated microchannel plate, which would allow for detecting such low charge densities by monitoring the synchrotron radiation emitted in the dedicated diagnostics port. We show results of beam test experiments at the Advanced Light Source (ALS) using a Hamamatsu 5961U MCP-PMT, which indicate that such an instrument has the required sensitivity to meet LHC specifications

The Large Hadron Collider unraveling the mysteries of the universe

CERN Document Server

Beech, Martin

2010-01-01

The Large Hadron Collider (LHC) is the largest engineering project ever undertaken, and one of the most expensive. Why are physicists around the world so excited about it? What secrets of the universe does this gargantuan piece of machinery hope to reveal? What risks are there in operating it? Could the exotic particles that are produced in the collisions—including tiny black holes that should wink into and out of existence— between subatomic particles be a threat not only to humankind but to the planet itself? In this thorough and engaging review of cutting-edge physics and cosmology, you will learn why the collider was built and how it works. You will find out what scientists are hoping to find out and what current aspects of the Standard Model might need to be revised. You will even learn about the quest to identify so-called dark matter and dark energy, which many now feel make up most of what's out there. This is a wild ride into some very unfamiliar and strange territory, but it is well worth your t...

The High Luminosity Large Hadron Collider the new machine for illuminating the mysteries of Universe

CERN Document Server

Brüning, Oliver

2015-01-01

This book provides a broad introduction to the physics and technology of the High Luminosity Large Hadron Collider (HL-LHC). This new configuration of the LHC is one of the major accelerator projects for the next 15 years and will give new life to the LHC after its first 15-year operation. Not only will it allow more precise measurements of the Higgs boson and of any new particles that might be discovered in the next LHC run, but also extend the mass limit reach for detecting new particles. The HL-LHC is based on the innovative accelerator magnet technologies capable of generating 11–13 Tesla fields, with effectiveness enhanced by use of the new Achromatic Telescopic Squeezing scheme, and other state-of-the-art accelerator technologies, such as superconducting compact RF crab cavities, advanced collimation concepts, and novel power technology based on high temperature superconducting links. The book consists of a series of chapters touching on all issues of technology and design, and each chapter can be re...

VUV photoemission studies of candidate Large Hadron Collider vacuum chamber materials

Directory of Open Access Journals (Sweden)

R. Cimino

1999-06-01

Full Text Available In the context of future accelerators and, in particular, the beam vacuum of the Large Hadron Collider (LHC, a 27 km circumference proton collider to be built at CERN, VUV synchrotron radiation (SR has been used to study both qualitatively and quantitatively candidate vacuum chamber materials. Emphasis is given to show that angle and energy resolved photoemission is an extremely powerful tool to address important issues relevant to the LHC, such as the emission of electrons that contributes to the creation of an electron cloud which may cause serious beam instabilities and unmanageable heat loads on the cryogenic system. Here we present not only the measured photoelectron yields from the proposed materials, prepared on an industrial scale, but also the energy and in some cases the angular dependence of the emitted electrons when excited with either a white light (WL spectrum, simulating that in the arcs of the LHC, or monochromatic light in the photon energy range of interest. The effects on the materials examined of WL irradiation and /or ion sputtering, simulating the SR and ion bombardment expected in the LHC, were investigated. The studied samples exhibited significant modifications, in terms of electron emission, when exposed to the WL spectrum from the BESSY Toroidal Grating Monochromator beam line. Moreover, annealing and ion bombardment also induce substantial changes to the surface thereby indicating that such surfaces would not have a constant electron emission during machine operation. Such characteristics may be an important issue to define the surface properties of the LHC vacuum chamber material and are presented in detail for the various samples analyzed. It should be noted that all the measurements presented here were recorded at room temperature, whereas the majority of the LHC vacuum system will be maintained at temperatures below 20 K. The results cannot therefore be directly applied to these sections of the machine until

Heavy-ion collimation at the Large Hadron Collider. Simulations and measurements

Energy Technology Data Exchange (ETDEWEB)

Hermes, Pascal Dominik

2016-12-19

The CERN Large Hadron Collider (LHC) stores and collides proton and {sup 208}Pb{sup 82+} beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets can still scatter out of the collimation system. When they irradiate the superconducting LHC magnets, the latter risk to quench (lose their superconducting property). These secondary collimation losses can potentially impose a limitation for the stored heavy-ion beam energy. Therefore, their distribution in the LHC needs to be understood by sophisticated simulations. Such simulation tools must accurately simulate the particle motion of many different nuclides in the magnetic LHC lattice and simulate their interaction with the collimators. Previous simulation tools used simplified models for the simulation of particle-matter interaction and showed discrepancies compared to the measured loss patterns. This thesis describes the development and application of improved heavy-ion collimation simulation tools. Two different approaches are presented to provide these functionalities. In the first presented tool, called STIER, fragmentation at the primary collimator is simulated with the Monte-Carlo event generator FLUKA. The ion fragments scattered out of the primary collimator are subsequently tracked as protons with ion-equivalent rigidities in the existing proton tracking tool SixTrack. This approach was used to prepare the collimator settings for the 2015 LHC heavy-ion run and its predictions allowed reducing undesired losses. More accurate simulation results are obtained with the second presented simulation tool, in which SixTrack is extended to track arbitrary heavy ions. This new

Heavy-ion collimation at the Large Hadron Collider. Simulations and measurements

International Nuclear Information System (INIS)

Hermes, Pascal Dominik

2016-01-01

The CERN Large Hadron Collider (LHC) stores and collides proton and 208 Pb 82+ beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets can still scatter out of the collimation system. When they irradiate the superconducting LHC magnets, the latter risk to quench (lose their superconducting property). These secondary collimation losses can potentially impose a limitation for the stored heavy-ion beam energy. Therefore, their distribution in the LHC needs to be understood by sophisticated simulations. Such simulation tools must accurately simulate the particle motion of many different nuclides in the magnetic LHC lattice and simulate their interaction with the collimators. Previous simulation tools used simplified models for the simulation of particle-matter interaction and showed discrepancies compared to the measured loss patterns. This thesis describes the development and application of improved heavy-ion collimation simulation tools. Two different approaches are presented to provide these functionalities. In the first presented tool, called STIER, fragmentation at the primary collimator is simulated with the Monte-Carlo event generator FLUKA. The ion fragments scattered out of the primary collimator are subsequently tracked as protons with ion-equivalent rigidities in the existing proton tracking tool SixTrack. This approach was used to prepare the collimator settings for the 2015 LHC heavy-ion run and its predictions allowed reducing undesired losses. More accurate simulation results are obtained with the second presented simulation tool, in which SixTrack is extended to track arbitrary heavy ions. This new tracking

Status of superconducting magnet development (SSC, RHIC, LHC)

International Nuclear Information System (INIS)

Wanderer, P.

1993-01-01

This paper summarize recent superconducting accelerator magnet construction and test activities at the Superconducting Super Collider Laboratory (SSC), the Large Hadron Collider at CERN (LHC), and the Relativistic Heavy Ion Collider at Brookhaven (RHIC). Future plan are also presented

Comprehending particle production in proton+proton and heavy-ion collisions at the Large Hadron Collider

International Nuclear Information System (INIS)

Sahoo, Raghunath

2017-01-01

In the extreme conditions of temperature and energy density, nuclear matter undergoes a transition to a new phase, which is governed by partonic degrees of freedom. This phase is called Quark-Gluon Plasma (QGP). The transition to QGP phase was conjectured to take place in central nucleus-nucleus collisions. With the advent of unprecedented collision energy at the Large Hadron Collider (LHC), at CERN, it has been possible to create energy densities higher than that was predicted by lattice QCD for a deconfinement transition

Heavy-Quark Associated Production with One Hard Photon at Hadron Colliders

Energy Technology Data Exchange (ETDEWEB)

Hartanto, Heribertus Bayu [Florida State Univ., Tallahassee, FL (United States)

2013-01-01

We present the calculation of heavy-quark associated production with a hard photon at hadron colliders, namely $pp(p\\bar p) → Q\\bar Q +X$γ (for $Q=t,b$), at Next-to-Leading Order (NLO) in Quantum Chromodynamics (QCD). We study the impact of NLO QCD corrections on the total cross section and several differential distributions at both the Tevatron and the Large Hadron Collider (LHC). For $t\\bar t$γ production we observe a sizeable reduction of the renormalization and factorization scale dependence when the NLO QCD corrections are included, while for $b\\bar b$γ production a considerable scale dependence still persists at NLO in QCD. This is consistent with what emerges in similar processes involving $b$ quarks and vector bosons and we explain its origin in detail. For $b\\bar b$γ production we study both the case in which at least one $b$ jet and the case in which at least two $b$ jets are observed. We perform the $b\\bar b$γ calculation using the Four Flavor Number Scheme (4FNS) and compare the case where at least one $b$ jet is observed with the corresponding results from the Five Flavor Number Scheme (5FNS) calculation. Finally we compare our results for $p\\bar p →+b+X$γ with the Tevatron data.

Towards the International Linear Collider

International Nuclear Information System (INIS)

Lopez-Fernandez, Ricardo

2006-01-01

The broad physics potential of e+e- linear colliders was recognized by the high energy physics community right after the end of LEP in 2000. In 2007, the Large Hadron Collider (LHC) now under construction at CERN will obtain its first collisions. The LHC, colliding protons with protons at 14 TeV, will discover a standard model Higgs boson over the full potential mass range, and should be sensitive to new physics into the several TeV range. The program for the Linear Collider (LC) will be set in the context of the discoveries made at the LHC. All the proposals for a Linear Collider will extend the discoveries and provide a wealth of measurements that are essential for giving deeper understanding of their meaning, and pointing the way to further evolution of particle physics in the future. For the mexican groups is the right time to join such an effort

Environmental monitoring at CERN: present status and future plans for the Large Hadron Collider (LHC)

International Nuclear Information System (INIS)

Hoefert, M.; Stevenson, G.R.; Vojtyla, P.; Wittekind, D.

1998-01-01

The present radiological impact of CERN on the environment is negligible. It is assessed that this will also be the case after the Large Hadron Collider starts operation in 2005. Nevertheless, the environmental monitoring programme at CERN will be further extended, so as to demonstrate that the Organization fully complies with standards and limits for environmental impact of nuclear installations as laid down by authorities in the CERN host countries. (P.A.)

Flat beams in a 50 TeV hadron collider

International Nuclear Information System (INIS)

Peggs, S.; Harrison, M.; Pilat, F.; Syphers, M.

1997-01-01

The basic beam dynamics of a next generation 50 x 50 TeV hadron collider based on a high field magnet approach have been outlined over the past several years. Radiation damping not only produces small emittances, but also flat beams, just as in electron machines. Based on open-quotes Snowmass 96close quotes parameters, we investigate the issues associated with flat beams in very high energy hadron colliders

PHOBOS in the LHC era

Energy Technology Data Exchange (ETDEWEB)

Steinberg, Peter, E-mail: peter.steinberg@bnl.gov

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)

Recent results from hadron colliders

International Nuclear Information System (INIS)

Frisch, H.J.

1990-01-01

This is a summary of some of the many recent results from the CERN and Fermilab colliders, presented for an audience of nuclear, medium-energy, and elementary particle physicists. The topics are jets and QCD at very high energies, precision measurements of electroweak parameters, the remarkably heavy top quark, and new results on the detection of the large flux of B mesons produced at these machines. A summary and some comments on the bright prospects for the future of hadron colliders conclude the talk. 39 refs., 44 figs., 3 tabs

Electron cloud buildup driving spontaneous vertical instabilities of stored beams in the Large Hadron Collider

Directory of Open Access Journals (Sweden)

Annalisa Romano

2018-06-01

Full Text Available At the beginning of the 2016 run, an anomalous beam instability was systematically observed at the CERN Large Hadron Collider (LHC. Its main characteristic was that it spontaneously appeared after beams had been stored for several hours in collision at 6.5 TeV to provide data for the experiments, despite large chromaticity values and high strength of the Landau-damping octupole magnet. The instability exhibited several features characteristic of those induced by the electron cloud (EC. Indeed, when LHC operates with 25 ns bunch spacing, an EC builds up in a large fraction of the beam chambers, as revealed by several independent indicators. Numerical simulations have been carried out in order to investigate the role of the EC in the observed instabilities. It has been found that the beam intensity decay is unfavorable for the beam stability when LHC operates in a strong EC regime.

Upgrade of the ATLAS Hadronic Tile Calorimeter for the High Luminosity LHC

Science.gov (United States)

Tortajada, Ignacio Asensi

2018-01-01

The Large Hadron Collider (LHC) has envisaged a series of upgrades towards a High Luminosity LHC (HL-LHC) delivering five times the LHC nominal instantaneous luminosity. The ATLAS Phase II upgrade, in 2024, will accommodate the upgrade of the detector and data acquisition system for the HL-LHC. The Tile Calorimeter (TileCal) will undergo a major replacement of its on- and off-detector electronics. In the new architecture, all signals will be digitized and then transferred directly to the off-detector electronics, where the signals will be reconstructed, stored, and sent to the first level of trigger at the rate of 40 MHz. This will provide better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Changes to the electronics will also contribute to the reliability and redundancy of the system. Three different front-end options are presently being investigated for the upgrade, two of them based on ASICs, and a final solution will be chosen after extensive laboratory and test beam studies that are in progress. A hybrid demonstrator module is being developed using the new electronics while conserving compatibility with the current system. The status of the developments will be presented, including results from the several tests with particle beams.

NLO corrections to production of heavy particles at hadron colliders

International Nuclear Information System (INIS)

Pagani, Davide

2013-01-01

In this thesis we study specific aspects of the production of heavy particles at hadron colliders, with emphasis on precision predictions including next-to-leading order (NLO) corrections from the strong and electroweak interactions. In the first part of the thesis we consider the top quark charge asymmetry. In particular, we discuss in detail the calculation of the electroweak contributions from the asymmetric part of the top quark pair production cross section at O(α 2 s α) and O(α 2 ) and their numerical impact on predictions for the asymmetry measurements at the Tevatron. These electroweak contributions provide a non-negligible addition to the QCD-induced asymmetry with the same overall sign and, in general, enlarge the Standard Model predictions by a factor around 1.2, diminishing the deviations from experimental measurements. In the second part of the thesis we consider the production of squarks, the supersymmetric partners of quarks, at the Large Hadron Collider (LHC). We discuss the calculation of the contribution of factorizable NLO QCD corrections to the production of squark-squark pairs combined at fully differential level with squark decays. Combining the production process with two different configurations for the squark decays, our calculation is used to provide precise phenomenological predictions for two different experimental signatures that are important for the search of supersymmetry at the LHC. We focus, for one signature, on the impact of our results on important physical differential distributions and on cut-and-count searches performed by the ATLAS and CMS collaborations. Considering the other signature, we analyze the effects from NLO QCD corrections and from the combination of production and decays on distributions relevant for parameter determination. In general, factorizable NLO QCD corrections have to be taken into account to obtain precise phenomenological predictions for the analyzed distributions and inclusive quantities. Moreover

Lead Ions and Coulomb's Law at the LHC (CERN)

Science.gov (United States)

Cid-Vidal, Xabier; Cid, Ramon

2018-01-01

Although for most of the time the Large Hadron Collider (LHC) at CERN collides protons, for around one month every year lead ions are collided, to expand the diversity of the LHC research programme. Furthermore, in an effort not originally foreseen, proton-lead collisions are also taking place, with results of high interest to the physics…

Phenomenology of the Higgs at the hadron colliders: from the standard model to supersymmetry

International Nuclear Information System (INIS)

Baglio, J.

2011-10-01

This thesis has been conducted in the context of one of the utmost important searches at current hadron colliders, that is the search for the Higgs boson, the remnant of the electroweak symmetry breaking. We wish to study the phenomenology of the Higgs boson in both the Standard Model (SM) framework and its minimal Supersymmetric extension (MSSM). After a review of the Standard Model in a first part and of the key reasons and ingredients for the supersymmetry in general and the MSSM in particular in a third part, we will present the calculation of the inclusive production cross sections of the Higgs boson in the main channels at the two current hadron colliders that are the Fermilab Tevatron collider and the CERN Large Hadron Collider (LHC), starting by the SM case in the second part and presenting the MSSM results, where we have 5 Higgs bosons and focusing on the two main production channels that are the gluon gluon fusion and the bottom quarks fusion, in the fourth part. The main output of this calculation is the extensive study of the various theoretical uncertainties that affect the predictions: the scale uncertainties which probe our ignorance of the higher-order terms in a fixed order perturbative calculation, the parton distribution functions (PDF) uncertainties and its related uncertainties from the value of the strong coupling constant, and the uncertainties coming from the use of an effective field theory to simplify the hard calculation. We then move on to the study of the Higgs decay branching ratios which are also affected by diverse uncertainties. We will present the combination of the production cross sections and decay branching fractions in some specific cases which will show interesting consequences on the total theoretical uncertainties. We move on to present the results confronted to experiments and show that the theoretical uncertainties have a significant impact on the inferred limits either in the SM search for the Higgs boson or on the MSSM

Collider and Detector Protection at Beam Accidents

Science.gov (United States)

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

2003-12-01

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

Collider and Detector Protection at Beam Accidents

International Nuclear Information System (INIS)

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

2003-01-01

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

Collider and detector protection at beam accidents

International Nuclear Information System (INIS)

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

2003-01-01

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

The LHC Tier1 at PIC: Experience from first LHC run

International Nuclear Information System (INIS)

Flix, J.; Perez-Calero Yzquierdo, A.; Accion, E.; Acin, V.; Acosta, C.; Bernabeu, G.; Bria, A.; Casals, J.; Caubet, M.; Cruz, R.; Delfino, M.; Espinal, X.; Lanciotti, E.; Lopez, F.; Martinez, F.; Mendez, V.; Merino, G.; Pacheco, A.; Planas, E.; Porto, M. C.; Rodriguez, B.; Sedov, A.

2013-01-01

This paper summarizes the operational experience of the Tier1 computer center at Port d'Informacio Cientifica (PIC) supporting the commissioning and first run (Run1) of the Large Hadron Collider (LHC). The evolution of the experiment computing models resulting from the higher amounts of data expected after there start of the LHC are also described. (authors)

Longitudinal emittance blowup in the large hadron collider

CERN Document Server

Baudrenghien, P

2013-01-01

The Large Hadron Collider (LHC) relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blowup provides the required emittance growth. The method was implemented through the summer of 2010. Band-limited RF phase-noise is injected in the main accelerating cavities during the whole ramp of about 11min. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are set by pre-defined constants, making the diffusion stop at the edges of the demanded distribution. The noise amplitude is controlled by feedback using the measurement of the average bunch length. This algorithm reproducibly achieves the programmed bunch length of about 1.2ns, at flat top with low bunch-to-bunch scatter and provides a...

Sextupole correction magnets for the Large Hadron Collider

CERN Document Server

Meinke, R B; Senti, M; Op de Beeck, W J; De Ryck, C; MacKay, W W

1999-01-01

About 2500 superconducting sextupole corrector magnets (MCS) are needed for the Large Hadron Collider (LHC) at CERN to compensate persistent current sextupole fields of the main dipoles. The MCS is a cold bore magnet with iron yoke. The coils are made from a NbTi conductor, which is cooled to 1.9 K. In the original CERN design 6 individual sub-coils, made from a monolithic composite conductor, are assembled and spliced together to form the sextupole. The coils are individually wound around precision-machined central islands and stabilized with matching saddle pieces at both ends. The Advanced Magnet Lab, Inc. (AML) has produced an alternative design, which gives improved performance and reliability at reduced manufacturing cost. In the AML design, the magnet consists of three splice-free sub-coils, which are placed with an automated winding process into pockets of prefabricated G-11 support cylinders. Any assembly process of sub-coils with potential misalignment is eliminated. The AML magnet uses a Kapton-wra...

Probing high scale physics with top quarks at the Large Hadron Collider

Science.gov (United States)

Dong, Zhe

With the Large Hadron Collider (LHC) running at TeV scale, we are expecting to find the deviations from the Standard Model in the experiments, and understanding what is the origin of these deviations. Being the heaviest elementary particle observed so far in the experiments with the mass at the electroweak scale, top quark is a powerful probe for new phenomena of high scale physics at the LHC. Therefore, we concentrate on studying the high scale physics phenomena with top quark pair production or decay at the LHC. In this thesis, we study the discovery potential of string resonances decaying to t/tbar final state, and examine the possibility of observing baryon-number-violating top-quark production or decay, at the LHC. We point out that string resonances for a string scale below 4 TeV can be detected via the t/tbar channel, by reconstructing center-of-mass frame kinematics of the resonances from either the t/tbar semi-leptonic decay or recent techniques of identifying highly boosted tops. For the study of baryon-number-violating processes, by a model independent effective approach and focusing on operators with minimal mass-dimension, we find that corresponding effective coefficients could be directly probed at the LHC already with an integrated luminosity of 1 inverse femtobarns at 7 TeV, and further constrained with 30 (100) inverse femtobarns at 7 (14) TeV.

The LHC on Google

CERN Multimedia

2009-01-01

Where in the world could the LHC outdo Barack Obama in the popularity stakes? On Google, of course! The famous search engine has just published its Top Ten "most popular" and "fastest rising" searches for 2008 in each of 34 countries. Surprise, surprise, the term "Large Hadron Collider" was the 6th fastest rising topic in the United Kingdom and the 10th fastest in New Zealand. In the UK, "Large Hadron Collider" even beat "Obama" into 7th place!

arXiv Energy-Frontier Lepton-Hadron Collisions at CERN: the LHeC and the FCC-eh

CERN Document Server

Kuze, Masahiro

2018-05-03

Lepton-hadron colliders that use a proton or nucleus beam of current and future hadron colliders and let it collide with an electron beam from a newly built electron accelerator bring attractive physics programs which are strong and complementary to the hadron collider physics. Machine development for Energy Recovery LINAC and physics performance studies of such electron-hadron colliders, specifically the LHeC that uses the existing LHC beam and FCC-eh that is an option of Future Circular Collider program, are ongoing and reviewed in this article.

Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

Science.gov (United States)

Bruce, R.; Assmann, R. W.; Boccone, V.; Bracco, C.; Brugger, M.; Cauchi, M.; Cerutti, F.; Deboy, D.; Ferrari, A.; Lari, L.; Marsili, A.; Mereghetti, A.; Mirarchi, D.; Quaranta, E.; Redaelli, S.; Robert-Demolaize, G.; Rossi, A.; Salvachua, B.; Skordis, E.; Tambasco, C.; Valentino, G.; Weiler, T.; Vlachoudis, V.; Wollmann, D.

2014-08-01

The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010-2013, the LHC was routinely storing protons at 3.5-4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An uncontrolled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multistage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the collimation system. The studies include tracking of protons through the fields of more than 5000 magnets in the 27 km LHC ring over hundreds of revolutions, and Monte Carlo simulations of particle-matter interactions both in collimators and machine elements being hit by escaping particles. The simulation results agree typically within a factor 2 with measurements of beam loss distributions from the previous LHC run. Considering the complex simulation, which must account for a very large number of unknown imperfections, and in view of the total losses around the ring spanning over 7 orders of magnitude, we consider this an excellent agreement. Our results give confidence in the simulation tools, which are used also for the design of future accelerators.

Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

Directory of Open Access Journals (Sweden)

R. Bruce

2014-08-01

Full Text Available The CERN Large Hadron Collider (LHC is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010–2013, the LHC was routinely storing protons at 3.5–4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An uncontrolled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multistage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the collimation system. The studies include tracking of protons through the fields of more than 5000 magnets in the 27 km LHC ring over hundreds of revolutions, and Monte Carlo simulations of particle-matter interactions both in collimators and machine elements being hit by escaping particles. The simulation results agree typically within a factor 2 with measurements of beam loss distributions from the previous LHC run. Considering the complex simulation, which must account for a very large number of unknown imperfections, and in view of the total losses around the ring spanning over 7 orders of magnitude, we consider this an excellent agreement. Our results give confidence in the simulation tools, which are used also for the design of future accelerators.

Applications of SCET to the pair production of supersymmetric particles at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Broggio, Alessandro

2013-02-04

In this thesis we investigate the phenomenology of supersymmetric particles at hadron colliders beyond next-to-leading order (NLO) in perturbation theory. We discuss the foundations of Soft-Collinear Effective Theory (SCET) and, in particular, we explicitly construct the SCET Lagrangian for QCD. As an example, we discuss factorization and resummation for the Drell-Yan process in SCET. We use techniques from SCET to improve existing calculations of the production cross sections for slepton-pair production and top-squark-pair production at hadron colliders. As a first application, we implement soft-gluon resummation at next-to-next-to-next-to-leading logarithmic order (NNNLL) for slepton-pair production in the minimal supersymmetric extension of the Standard Model (MSSM). This approach resums large logarithmic corrections arising from the dynamical enhancement of the partonic threshold region caused by steeply falling parton luminosities. We evaluate the resummed invariant-mass distribution and total cross section for slepton-pair production at the Tevatron and LHC and we match these results, in the threshold region, onto NLO fixed-order calculations. As a second application we present the most precise predictions available for top-squark-pair production total cross sections at the LHC. These results are based on approximate NNLO formulas in fixed-order perturbation theory, which completely determine the coefficients multiplying the singular plus distributions. The analysis of the threshold region is carried out in pair invariant mass (PIM) kinematics and in single-particle inclusive (1PI) kinematics. We then match our results in the threshold region onto the exact fixed-order NLO results and perform a detailed numerical analysis of the total cross section.

The LHC road at CERN

International Nuclear Information System (INIS)

Anon.

1989-01-01

To explore the 1 TeV energy scale where fundamental particle interactions should encounter new conditions, two major routes were proposed - a high magnetic field proton collider in the LEP tunnel, dubbed LHC for Large Hadron Collider, and the CERN Linear Collider (CLIC) to supply beams of electrons and positrons. Exploratory studies have shown that while CLIC remains a valid long-term goal, LHC appears as the most cost-effective way for CERN to enter the 1 TeV arena. High-field superconducting magnet prototype work demonstrates that a 'two-in-one' design supplying the 10 tesla fields needed to handle LHC's 8 TeV proton beams (collision energy 16 TeV) is a practical proposition. (orig./HSI).

Physics programmes of the restarted LHC

International Nuclear Information System (INIS)

Tokushuku, Katsuo

2011-01-01

Experimental programs at the Large Hadron Collider (LHC) have started. On March 30th in 2010, proton beams collided at 7 TeV in the LHC, at the highest center-of-mass energy the humankind has ever produced. The machine will be operated almost continuously until the end of 2011, providing many collision data to explore new physics in the TeV region. The LHC has recovered from the unfortunate helium-leak incident in September 2009. In this article, after describing the history of the consolidation works in the LHC, physics prospects from the 2 year run are discussed. (author)

The Large Hadron Collider

CERN Document Server

Juettner Fernandes, Bonnie

2014-01-01

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

Measurement of very forward neutron energy spectra for 7 TeV proton--proton collisions at the Large Hadron Collider

CERN Document Server

Adriani, O.; Bonechi, L.; Bongi, M.; Castellini, G.; D'Alessandro, R.; Del Prete, M.; Haguenauer, M.; Itow, Y.; Kasahara, K.; Kawade, K.; Makino, Y.; Masuda, K.; Matsubayashi, E.; Menjo, H.; Mitsuka, G.; Muraki, Y.; Okuno, Y.; Papini, P.; Perrot, A-L.; Ricciarini, S.; Sako, T.; Sakurai, N.; Sugiura, Y.; Suzuki, T.; Tamura, T.; Tiberio, A.; Torii, S.; Tricomi, A.; Turner, W.C.; Zhou, Q.D.

2015-01-01

The Large Hadron Collider forward (LHCf) experiment is designed to use the LHC to verify the hadronic-interaction models used in cosmic-ray physics. Forward baryon production is one of the crucial points to understand the development of cosmic-ray showers. We report the neutron-energy spectra for LHC $\\sqrt{s}$ = 7 TeV proton--proton collisions with the pseudo-rapidity $\\eta$ ranging from 8.81 to 8.99, from 8.99 to 9.22, and from 10.76 to infinity. The measured energy spectra obtained from the two independent calorimeters of Arm1 and Arm2 show the same characteristic feature before unfolding the difference in the detector responses. We unfolded the measured spectra by using the multidimensional unfolding method based on Bayesian theory, and the unfolded spectra were compared with current hadronic-interaction models. The QGSJET II-03 model predicts a high neutron production rate at the highest pseudo-rapidity range similar to our results and the DPMJET 3.04 model describes our results well at the lower pseudo-...

Photon-Photon Luminosities in Relativistic Heavy Ion Collisions at LHC Energies

OpenAIRE

Hencken, Kai; Trautmann, Dirk; Baur, Gerhard

1994-01-01

Effective photon-photon luminosities are calculated for various realistic hadron collider scenarios. The main characteristics of photon-photon processes at relativistic heavy-ion colliders are established and compared to the corresponding photon-photon luminosities at electron-positron and future Photon Linear Colliders (PLC). Higher order corrections as well as inelastic processes are discussed. It is concluded that feasible high luminosity Ca-Ca collisions at the Large Hadron Collider (LHC)...

submitter LHC experiments

CERN Document Server

Tanaka, Shuji

2001-01-01

Large Hadron Collider (LHC) is under construction at the CERN Laboratory in Switzerland. Four experiments (ATLAS, CMS, LHCb, ALICE) will try to study the new physics by LHC from 2006. Its goal to explore the fundamental nature of matter and the basic forces. The PDF file of the transparency is located on http://www-atlas.kek.jp/sub/documents/lepsymp-stanaka.pdf.

Large Hadron Collider at CERN: Beams Generating High-Energy-Density Matter

CERN Document Server

Tahir, N A; Shutov, A; Lomonosov, IV; Piriz, A R; Hoffmann, D H H; Deutsch, C; Fortov, V E

2009-01-01

This paper presents numerical simulations that have been carried out to study the thermodynamic and hydrodynamic response of a solid copper cylindrical target that is facially irradiated along the axis by one of the two Large Hadron Collider (LHC) 7 TeV/c proton beams. The energy deposition by protons in solid copper has been calculated using an established particle interaction and Monte Carlo code, FLUKA, which is capable of simulating all components of the particle cascades in matter, up to multi-TeV energies. This data has been used as input to a sophisticated two--dimensional hydrodynamic computer code, BIG2 that has been employed to study this problem. The prime purpose of these investigations was to assess the damage caused to the equipment if the entire LHC beam is lost at a single place. The FLUKA calculations show that the energy of protons will be deposited in solid copper within about 1~m assuming constant material parameters. Nevertheless, our hydrodynamic simulations have shown that the energy de...

Last magnet in place for colossal collider

CERN Document Server

Cho, Adrian

2007-01-01

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

CERN - the W and the LHC

CERN Document Server

Rodgers, P

2003-01-01

Construction of the Large Hadron Collider (LHC) and its detectors at the CERN laboratory in Geneva is a challenge of Himalayan proportions. The LHC will collide protons at energies of 14 TeV (14 million million electrons volts) and two detectors - ATLAS and CMS - will survey the debris of these collisions for signs of the Higgs boson, supersymmetric particles, large extra dimensions and other evidence of new physics beyond the Standard Model. (U.K.)

Beleaguered LHC gears up for restart

CERN Multimedia

Cartwright, Jon

2009-01-01

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

First Considerations on Beam Optics and Lattice Design for the Future Hadron-Hadron Collider FCC

CERN Document Server

Alemany Fernandez, R

2014-01-01

The present document explains the steps carried out in order to make the first design of the Future Hadron-Hadron Collider (FCC-hh) following the base line parameters that can be found in [1]. Two lattice layouts are presented, a ring collider with 12 arcs and 12 straight sections, four of them designed as interaction points, and a racetrack like collider with two arcs and two straight sections, each of them equipped with two interaction points. The lattice design presented in the paper is modular allowing the same modules be used for both layouts. The present document addresses as well the beta star reach at the interaction points.

Physics possibilities of lepton and hadron colliders

International Nuclear Information System (INIS)

Peccei, R.D.

1985-05-01

After a brief introduction to lepton and hadron colliders presently being planned, I give some examples of the nice standard physics which is expected to be seen in them. The bulk of the discussion, however, is centered on signals for new physics. Higgs searches at the new colliders are discussed, as well as signatures and prospects for detecting effects of supersymmetry, compositeness and dynamical symmetry breakdown. (orig.)

Electroweak results from hadron colliders

International Nuclear Information System (INIS)

Demarteau, Marcel

1997-01-01

A review of recent electroweak results from hadron colliders is given. Properties of the W ± and Z 0 gauge bosons using final states containing electrons and muons based on large integrated luminosities are presented. The emphasis is placed on the measurement of the mass of the W boson and the measurement of trilinear gauge boson couplings

Hard QCD at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Moch, S

2008-02-15

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

Hard QCD at hadron colliders

International Nuclear Information System (INIS)

Moch, S.

2008-02-01

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

3rd CERN-Fermilab Hadron Collider Physics Summer School

CERN Multimedia

2008-01-01

August 12-22, 2008, Fermilab The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 29 FEBRUARY 2008. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high-energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The third session of the summer school will focus on exposing young post-docs and advanced graduate students to broader theories and real data beyond what they’ve learned at their home institutions. Experts from across the globe will lecture on the theoretical and experimental foundations of hadron collider physics, host parallel discussion sessions and answer students’ questions. This year’s school will also have a greater focus on physics beyond the Standard Model, as well as more time for questions at the end of each lecture. The 2008 School will be held at ...

3rd CERN-Fermilab HadronCollider Physics Summer School

CERN Multimedia

EP Department

2008-01-01

August 12-22, 2008, Fermilab The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 29 FEBRUARY 2008. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high-energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The third session of the summer school will focus on exposing young post-docs and advanced graduate students to broader theories and real data beyond what they’ve learned at their home institutions. Experts from across the globe will lecture on the theoretical and experimental foundations of hadron collider physics, host parallel discussion sessions and answer students’ questions. This year’s school will also have a greater focus on physics beyond the Standard Model, as well as more time for questions at the end of each lecture. The 2008 School will be held at Fermilab. Further enquiries should ...

12th CERN-Fermilab Hadron Collider Physics Summer School

CERN Document Server

2017-01-01

CERN and Fermilab are jointly offering a series of "Hadron Collider Physics Summer Schools", to prepare young researchers for these exciting times. The school has alternated between CERN and Fermilab, and will return to CERN for the twelfth edition, from 28th August to 6th September 2017. The CERN-Fermilab Hadron Collider Physics Summer School is an advanced school targeted particularly at young postdocs and senior PhD students working towards the completion of their thesis project, in both Experimental High Energy Physics (HEP) and phenomenology. Other schools, such as the CERN European School of High Energy Physics, may provide more appropriate training for students in experimental HEP who are still working towards their PhDs. Mark your calendar for 28 August - 6 September 2017, when CERN will welcome students to the twelfth CERN-Fermilab Hadron Collider Physics Summer School. The School will include nine days of lectures and discussions, and one free day in the middle of the period. Limited scholarship ...

1st Large Hadron Collider Physics Conference

CERN Document Server

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

2013-01-01

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

The Large Hadron Collider and the Super Proton Synchrotron at CERN as Tools to Generate Warm Dense Matter and Non–Ideal Plasmas

CERN Document Server

Tahir, N A; Shutov, A; Lomonosov, I V; Gryaznov, V; Piriz, A R; Deutsch, C; Fortov, V E

2011-01-01

The largest accelerator in the world, the Large Hadron Collider (LHC) at CERN, has entered into commission- ing phase. It is expected that when this impressive machine will become fully operational, it will generate two counter rotating 7 TeV/c proton beams that will be made to collide, leading to an unprecedented luminosity of 1034 cm−2s−1. Total energy stored in each LHC beam is about 362 MJ, sufficient to melt 500 kg copper. Safety of operation is a very critical issue when working with such extremely powerful beams. It is important to know the consequences of an accidental release of the beam energy in order to design protection system for the equipment. For this purpose we have carried out extensive numerical simulations of the interaction of one full LHC beam with copper and graphite targets which are materials of practical importance. Our calculations have shown that the LHC protons will penetrate up to about 35 m in solid copper and 10 m in solid graphite. A very interesting outcome of this work i...

The Large Hadron Collider and the Super Proton Synchrotron at CERN as Tools to Generate Warm Dense Matter and Non-Ideal Plasmas

CERN Document Server

Tahir, N A; Deutsch, C; Gryaznov, V; Lomonosov, I V; Shutov, A; Piriz, A R; Fortov, V E; Geissel, H; Redmer, R

2011-01-01

The largest accelerator in the world, the Large Hadron Collider (LHC) at CERN, has entered into commissioning phase. It is expected that when this impressive machine will become fully operational, it will generate two counter rotating 7 TeV/c proton beams that will be made to collide, leading to an unprecedented luminosity of 10(34) cm(-2)s(-1). Total energy stored in each LHC beam is about 362 MJ, sufficient to melt 500 kg copper. Safety of operation is a very critical issue when working with such extremely powerful beams. It is important to know the consequences of an accidental release of the beam energy in order to design protection system for the equipment. For this purpose we have carried out extensive numerical simulations of the interaction of one full LHC beam with copper and graphite targets which are materials of practical importance. Our calculations have shown that the LHC protons will penetrate up to about 35 m in solid copper and 10 m in solid graphite. A very interesting outcome of this work i...

LHC brochure (French version)

CERN Multimedia

Marcastel, Fabienne

2014-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (English version)

CERN Multimedia

AUTHOR|(CDS)2070305

2014-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (Italian version)

CERN Multimedia

Lefevre, Christiane

2011-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (French version)

CERN Multimedia

Lefevre, C

2010-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (Danish version)

CERN Multimedia

Lefevre, C

2010-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (English version)

CERN Multimedia

Lefevre, C

2010-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (German version)

CERN Multimedia

Marcastel, Fabienne

2014-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

CERN 's large hadron collider : Radiation protection aspects of design and commissioning

International Nuclear Information System (INIS)

Forkel-Wirth, Doris; Brugger, Markus; Menzel, Hans; Roesler, Stefan; Vincke, Heinz; Vincke, Helmut

2008-01-01

Full text: CERN, the world's largest particle physics laboratory provides high energy hadron beams for experiments exploring matter. For this purpose various accelerators are operated and in 2008 the last link will be added to the accelerator chain: beam will be injected into CERN 's new 'flagship', the Large Hadron Collider (LHC). From then on high energy physics experiments will exploit the LHC 's colliding beams of protons and lead ions with a center of mass energy of 14 TeV and 1150 TeV, respectively. Radiation Protection aspects were taken into account during the whole duration of the design phase. Conservative design constraints were defined in 1996; some years later some of them, in particular with respect to the dose to occupational exposed workers, had to be readjusted to account for the latest development in CERN 's radiation protection rules and regulations. Numerous radiation protection studies had been performed to ensure a lay-out of the machine and its experiments in compliance with these constraints. These studies assessed all radiation risks related to the various beam-operation modes of the accelerator. In all cases external exposure was identified as the major risk: due to high energetic, mixed radiation fields during beam-on and due to beta and gamma radiation fields caused by induced radioactivity during beam-off. Counter measures were implemented like an optimized beam operation to limit beam losses, installation of thick shielding, prohibition of access to the major part of the LHC underground areas during beam-operation and optimization of the equipment and its handling during maintenance and repair. Detailed Monte Carlo simulations were performed to derive from the various beam loss scenarios the dose rates the workers will be exposed to. Individual and collective doses were projected based on the calculations and the maintenance scenarios provided by the teams concerned. In an iterative way the lay-out of the various regions were optimized

Design and Installation Challenges of the Neutral Beam Absorbers for the Large Hadron Collider at CERN

OpenAIRE

Fernández Vélez, Óscar

2005-01-01

El CERN (Consejo Europeo de Investigación Nuclear) está construyendo su nuevo acelerador de partículas en la frontera franco-suiza. Actualmente en la fase de instalación, El Large Hadron Collider (LHC), con 26,7 kilómetros de longitud a 100 metros bajo tierra, será el mayor y más potente acelerador de partículas jamás construido. A su llegada al CERN, cada uno de casi 2000 imanes superconductores que formarán parte del acelerador debe ser verificado, ensamblado y transportado hasta ...

Big Bang test delayed at CERN's LHC until 2008

CERN Multimedia

Atkins, William

2007-01-01

"Scientists at the proton-proton Large Hadron Collider (LHC) particle accelerator and collider will postpone a test that could help solve the mystery of what happened a few nanoseconds after the Big Bang." (1 page)

The Local Helium Compound Transfer Lines for the Large Hadron Collider Cryogenic System

CERN Document Server

Parente, C; Munday, A; Wiggins, P

2006-01-01

The cryogenic system for the Large Hadron Collider (LHC) under construction at CERN will include twelve new local helium transfer lines distributed among five LHC points in underground caverns. These lines, being manufactured and installed by industry, will connect the cold boxes of the 4.5-K refrigerators and the 1.8-K refrigeration units to the cryogenic interconnection boxes. The lines have a maximum of 30-m length and may possess either small or large re-distribution units to allow connection to the interface ports. Due to space restrictions the lines may have complex routings and require several elbowed sections. The lines consist of a vacuum jacket, a thermal shield and either three or four helium process pipes. Specific internal and external supporting and compensation systems were designed for each line to allow for thermal contraction of the process pipes (or vacuum jacket, in case of a break in the insulation vacuum) and to minimise the forces applied to the interface equipment. Whenever possible, f...

Jet-hadron correlations relative to the event plane at the LHC with ALICE

Science.gov (United States)

Mazer, Joel; Alice Collaboration

2017-11-01

In ultra relativistic heavy-ion collisions at the Large Hadron Collider (LHC), conditions are met to produce a hot, dense and strongly interacting medium known as the Quark Gluon Plasma (QGP). Quarks and gluons from incoming nuclei collide to produce partons at high momenta early in the collisions. By fragmenting into collimated sprays of hadrons, these partons form 'jets'. The outgoing partons scatter and interact with the medium, leading to a manifestation of medium modifications of jets in the final state, known as jet quenching. Within the framework of perturbative QCD, jet production is well understood in pp collisions. We use jets measured in pp interactions as a baseline reference for comparing to heavy-ion collision systems to detect and study jet quenching. The jet quenching mechanism can be studied through the angular correlations of jets with charged hadrons and is examined in transverse momentum (pT) bins of the jets, pT bins of the associated hadrons, and as a function of collision centrality. A robust and precise background subtraction method is used in this analysis to remove the complex, flow dominated, heavy-ion background. The analysis of angular correlations for different orientations of the jet relative to the event plane allows for the study of the path-length dependence of medium modifications to jets. The event plane dependence of azimuthal angular correlations of charged hadrons with respect to the axis of an R = 0.2 reconstructed full (charged + neutral) jet in Pb-Pb collisions at √{sNN} = 2.76 TeV in ALICE is presented. Results are compared for three angular bins of the jet relative to the event plane in mid-peripheral events. The yields relative to the event plane are presented and then quantified through yield ratio calculations. The results show no significant path-length dependence on the medium modifications.

Press Conference: LHC Restart, Season 2

CERN Multimedia

CERN. Geneva

2015-01-01

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

LHC Brochure (german version)

CERN Multimedia

Vanoli, C.

2006-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (German version)

CERN Multimedia

Lefevre, C

2008-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (German version)

CERN Multimedia

Lefevre, Christiane

2011-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (Spanish version)

CERN Multimedia

Lefevre, C

2008-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

Precision Muon Tracking at Future Hadron Colliders with sMDT Chambers

CERN Document Server

Kortner, Oliver; Müller, Felix; Nowak, Sebastian; Richter, Robert

2016-01-01

Small-diameter muon drift tube (sMDT) chambers are a cost-effective technology for high-precision muon tracking. The rate capability of the sMDT chambers has been extensively tested at the Gamma Irradiation Facility at CERN in view of expected rates at future high-energy hadron colliders. Results show that it fulfills the requirements over most of the acceptance of muon detectors. The optimization of the read-out electronics to further increase the rate capability of the detectors is discussed. Chambers of this type are under construction for upgrades of the muon spectrometer of the ATLAS detector at high LHC luminosities. Design and construction procedures have been optimized for mass production while providing a precision of better than 10 micrometers in the sense wire positions and the mechanical stability required to cover large areas.

Future Circular Collider Study FCC-he Baseline Parameters

CERN Document Server

Bruning, Oliver; Klein, Max; Pellegrini, Dario; Schulte, Daniel; Zimmermann, Frank

2017-01-01

Initial considerations are presented on the FCC-he, the electron-hadron collider con guration within the Future Circular Collider study. This note considers arguments for the choice of the electron beam energy based on physics, ep scattering kinematics and cost. The default con guration for the electron accelerator, as for the LHeC, is chosen to be a multi-turn energy recovery linac external to the proton beam tunnel. The main accelerator parameters of the FCC-he are discussed, assuming the concurrent operation of ep with the 100TeV cms energy pp collider. These are compared with the LHeC design concept, for increased performance as for a Higgs facility using the HL-LHC, and also the high energy HE-LHC ep collider configuration. Initial estimates are also provided for the luminosity performance of electron-ion colliders for the 60 GeV electron ERL when combined with the LHC, the HE-LHC and the FCC ion beams.

A Demonstration Experiment for the Forecast of Magnetic Field and Field Errors in the Large Hadron Collider

CERN Document Server

Sammut, N J; Bottura, L; Deferne, G; Lamont, M; Miles, J; Sanfilippo, S; Strzelczyk, M; Venturini-Delsolaro, W; Xydi, P

2008-01-01

In order to reduce the burden on the beam-based feedback, the Large Hadron Collider control system is equipped with the Field Description for the LHC (FiDeL) which provides a forecast of the magnetic field and the multipole field errors. FiDeL has recently been extensively tested at CERN to determine main field tracking, multipole forecasting and compensation accuracy. This paper describes the rationale behind the tests, the procedures employed to power the main magnets and their correctors, and finally, we present the results obtained. We also give an indication of the prediction accuracy that the system can deliver during the operation of the LHC and we discuss the implications that these will have on the machine performance.

Production of electroweak bosons at hadron colliders: theoretical aspects

CERN Document Server

Mangano, Michelangelo L.

2016-01-01

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

LHC an unprecedented technological challenge

International Nuclear Information System (INIS)

Baruch, J.O.

2002-01-01

This article presents the future LHC (large hadron collider) in simple terms and gives some details concerning radiation detectors and supra-conducting magnets. LHC will take the place of the LEP inside the 27 km long underground tunnel near Geneva and is scheduled to operate in 2007. 8 years after its official launching the LHC project has piled up 2 year delay and has exceeded its initial budget (2 milliard euros) by 18%. Technological challenges and design difficulties are the main causes of these shifts. The first challenge has been carried out successfully, it was the complete clearing out of the LEP installation. In order to release 14 TeV in each proton-proton collision, powerful magnetic fields (8,33 Tesla) are necessary. 1248 supra-conducting 15 m-long bipolar magnets have to be built. 30% of the worldwide production of niobium-titanium wires will be used each year for 5 years in the design of these coils. The global cryogenic system will be gigantic and will use 94 tons of helium. 4 radiation detectors are being built: ATLAS (a toroidal LHC apparatus), CMS (compact muon solenoid), ALICE (a large ion collider experiment) and LHC-b (large hadron collider beauty). The 2 first will search after the Higgs boson, ALICE will be dedicated to the study of the quark-gluon plasma and LHC-b will gather data on the imbalance between matter and anti-matter. (A.C.)

Ntuples for NLO Events at Hadron Colliders

CERN Document Server

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

2014-01-01

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

On the Future High Energy Colliders

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2015-09-28

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

From the LHC to future colliders. CERN Theory Institute summary report

International Nuclear Information System (INIS)

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

2010-01-01

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 -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 -1 of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, the Working Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions. (orig.)

Final implementation, commissioning, and performance of embedded collimator beam position monitors in the Large Hadron Collider

Science.gov (United States)

Valentino, Gianluca; Baud, Guillaume; Bruce, Roderik; Gasior, Marek; Mereghetti, Alessio; Mirarchi, Daniele; Olexa, Jakub; Redaelli, Stefano; Salvachua, Belen; Valloni, Alessandra; Wenninger, Jorg

2017-08-01

During Long Shutdown 1, 18 Large Hadron Collider (LHC) collimators were replaced with a new design, in which beam position monitor (BPM) pick-up buttons are embedded in the collimator jaws. The BPMs provide a direct measurement of the beam orbit at the collimators, and therefore can be used to align the collimators more quickly than using the standard technique which relies on feedback from beam losses. Online orbit measurements also allow for reducing operational margins in the collimation hierarchy placed specifically to cater for unknown orbit drifts, therefore decreasing the β* and increasing the luminosity reach of the LHC. In this paper, the results from the commissioning of the embedded BPMs in the LHC are presented. The data acquisition and control software architectures are reviewed. A comparison with the standard alignment technique is provided, together with a fill-to-fill analysis of the measured orbit in different machine modes, which will also be used to determine suitable beam interlocks for a tighter collimation hierarchy.

Messung der Produktion von aus leichten Quarks zusammengesetzten Hadronen und Anti-Kernen am Large Hadron Collider

CERN Document Server

Kalweit, Alexander; Wambach, Jochen

With the recording of the first collisions of the Large Hadron Collider (LHC) in November 2009, a new era in the domain of high energy and relativistic heavy-ion physics has started. As one of the early observables which can be addressed, the measurement of light quark flavor production is presented in this thesis. Hadrons that consist only of u, d, and s quarks constitute the majority of the produced particles in pp and Pb–Pb collisions. Their measurement forms the basis for a detailed understanding of the collision and for the answer of the question if hadronic matter undergoes a phase transition to the deconfined quark-gluon plasma at high temperatures. The basics of ultra-relativistic heavyion physics are briefly introduced in the first chapter followed by a short description of the ALICE experiment. A particular focus is put on the unique particle identification (PID) capabilities as they provide the basis of the measurements which are presented in the following chapters. The particle identification vi...

First β-beating measurement and optics analysis for the CERN Large Hadron Collider

Directory of Open Access Journals (Sweden)

M. Aiba

2009-08-01

Full Text Available Proton beams were successfully steered through the entire ring of the CERN Large Hadron Collider (LHC on September the 10th of 2008. A reasonable lifetime was achieved for the counterclockwise beam, namely beam 2, after the radiofrequency capture of the particle bunch was established. This provided the unique opportunity of acquiring turn-by-turn betatron oscillations for a maximum of 90 turns right at injection. Transverse coupling was not corrected and chromaticity was estimated to be large. Despite this largely constrained scenario, reliable optics measurements have been accomplished. These measurements together with the application of new algorithms for the reconstruction of optics errors have led to the identification of a dominant error source.

VBS W±W±H production at the HL-LHC and a 100 TeV pp-collider

OpenAIRE

Englert, Christoph; Li, Qiang; Spannowsky, Michael; Wang, Mengmeng; Wang, Lei

2017-01-01

W±W±HW±W±H production at hadron colliders through vector boson scattering is a so far unconsidered process, which leads to a clean signature of two same-sign charged leptons and two widely separated jets. This process is sensitive to the HHHHHH and WWHHWWHH couplings and any deviation of these couplings from their SM predictions serves as direct evidence of new physics beyond the SM. In this paper, we perform a Monte Carlo study of this process for the s√=14TeVs=14TeV LHC and a 100 TeV pppp-c...

Partons and jets at the LHC

Indian Academy of Sciences (India)

Partons and jets at the LHC. DAVISON E SOPER. Institute of Theoretical Science, University of Oregon, Eugene, OR 97403-5203, USA. Abstract. I review some issues related to short distance QCD and its relation to the experimental program of the large hadron collider (LHC) now under construction in Geneva. Keywords.

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

CERN Document Server

Aad, Georges; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Aderholz, Michael; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Akiyama, Kunihiro; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Aliyev, Magsud; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral, Pedro; Amelung, Christoph; Ammosov, Vladimir; Amorim, Antonio; Amorós, Gabriel; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Astvatsatourov, Anatoli; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Ay, Cano; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barashkou, Andrei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Ben Ami, Sagi; Benary, Odette; Benchekroun, Driss; Benchouk, Chafik; Bendel, Markus; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertinelli, Francesco; Bertolucci, Federico; Besana, Maria Ilaria; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bitenc, Urban; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blazek, Tomas; Blocker, Craig; Blocki, Jacek; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boelaert, Nele; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bolnet, Nayanka Myriam; Bona, Marcella; Bondarenko, Valery; Bondioli, Mario; Boonekamp, Maarten; Booth, Chris; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borri, Marcello; Borroni, Sara; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Botterill, David; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozhko, Nikolay; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Braem, André; Branchini, Paolo; Brandenburg, George; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brelier, Bertrand; Bremer, Johan; Brenner, Richard; Bressler, Shikma; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brodbeck, Timothy; Brodet, Eyal; Broggi, Francesco; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, William; Brown, Gareth; Brown, Heather; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchanan, James; Buchanan, Norman; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Budick, Burton; Büscher, Volker; Bugge, Lars; Bulekov, Oleg; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgard, Carsten Daniel; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Bussey, Peter; Buszello, Claus-Peter; Butin, François; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Buttinger, William; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Caloi, Rita; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarri, Paolo; Cambiaghi, Mario; Cameron, David; Caminada, Lea Michaela; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Capasso, Luciano; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capriotti, Daniele; Capua, Marcella; Caputo, Regina; Caramarcu, Costin; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Carrillo Montoya, German D; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Caso, Carlo; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Cataneo, Fernando; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cauz, Diego; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cetin, Serkant Ali; Cevenini, Francesco; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Kevin; Chapleau, Bertrand; Chapman, John Derek; Chapman, John Wehrley; Chareyre, Eve; Charlton, Dave; Chavda, Vikash; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Shenjian; Chen, Tingyang; Chen, Xin; Cheng, Shaochen; Cheplakov, Alexander; Chepurnov, Vladimir; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Illectra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciba, Krzysztof; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciobotaru, Matei Dan; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Clifft, Roger; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coe, Paul; Cogan, Joshua Godfrey; Coggeshall, James; Cogneras, Eric; Colas, Jacques; Colijn, Auke-Pieter; Collard, Caroline; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colon, German; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Michele; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conventi, Francesco; Cook, James; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Costin, Tudor; Côté, David; Coura Torres, Rodrigo; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Crescioli, Francesco; Cristinziani, Markus; Crosetti, Giovanni; Crupi, Roberto; Crépé-Renaudin, Sabine; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Curatolo, Maria; Curtis, Chris; Cuthbert, Cameron; Cwetanski, Peter; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Silva, Paulo Vitor; Da Via, Cinzia; Dabrowski, Wladyslaw; Dai, Tiesheng; Dallapiccola, Carlo; Dam, Mogens; Dameri, Mauro; Damiani, Daniel; Danielsson, Hans Olof; Dannheim, Dominik; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Eleanor; Davies, Merlin; Davison, Adam; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Dawson, John; Daya, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Castro Faria Salgado, Pedro; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De La Taille, Christophe; De la Torre, Hector; De Lotto, Barbara; de Mora, Lee; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dean, Simon; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dedovich, Dmitri; Degenhardt, James; Dehchar, Mohamed; Del Papa, Carlo; Del Peso, Jose; Del Prete, Tarcisio; Delemontex, Thomas; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delruelle, Nicolas; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Deng, Jianrong; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Devetak, Erik; Deviveiros, Pier-Olivier; Dewhurst, Alastair; DeWilde, Burton; Dhaliwal, Saminder; Dhullipudi, Ramasudhakar; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Luise, Silvestro; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Diaz, Marco Aurelio; Diblen, Faruk; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dindar Yagci, Kamile; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Barros do Vale, Maria Aline; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobbs, Matt; Dobinson, Robert; Dobos, Daniel; Dobson, Ellie; Dobson, Marc; Dodd, Jeremy; Doglioni, Caterina; Doherty, Tom; Doi, Yoshikuni; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Dohmae, Takeshi; Donadelli, Marisilvia; Donega, Mauro; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dosil, Mireia; Dotti, Andrea; Dova, Maria-Teresa; Dowell, John; Doxiadis, Alexander; Doyle, Tony; Drasal, Zbynek; Drees, Jürgen; Dressnandt, Nandor; Drevermann, Hans; Driouichi, Chafik; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Duchovni, Ehud; Duckeck, Guenter; Dudarev, Alexey; Dudziak, Fanny; Dührssen, Michael; Duerdoth, Ian; Duflot, Laurent; Dufour, Marc-Andre; Dunford, Monica; Duran Yildiz, Hatice; Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Düren, Michael; Ebenstein, William; Ebke, Johannes; Eckweiler, Sebastian; Edmonds, Keith; Edwards, Clive; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Ehrich, Thies; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Eppig, Andrew; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienne, Francois; Etienvre, Anne-Isabelle; Etzion, Erez; Evangelakou, Despoina; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Fakhrutdinov, Rinat; Falciano, Speranza; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrington, Sinead; Farthouat, Philippe; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Favareto, Andrea; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Woiciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Fellmann, Denis; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Ferland, Jonathan; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrer, Maria Lorenza; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filippas, Anastasios; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fischer, Peter; Fisher, Matthew; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Fokitis, Manolis; Fonseca Martin, Teresa; Forbush, David Alan; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Foster, Joe; Fournier, Daniel; Foussat, Arnaud; Fowler, Andrew; Fowler, Ken; Fox, Harald; Francavilla, Paolo; Franchino, Silvia; Francis, David; Frank, Tal; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Friedrich, Felix; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Gan, KK; Gao, Yongsheng; Gapienko, Vladimir; Gaponenko, Andrei; Garberson, Ford; Garcia-Sciveres, Maurice; García, Carmen; García Navarro, José Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Garvey, John; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gayde, Jean-Christophe; Gazis, Evangelos; Ge, Peng; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilbert, Laura; Gilewsky, Valentin; Gillberg, Dag; Gillman, Tony; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Giugni, Danilo; Giunta, Michele; Giusti, Paolo; Gjelsten, Børge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Goddard, Jack Robert; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Göpfert, Thomas; Goeringer, Christian; Gössling, Claus; Göttfert, Tobias; Goldfarb, Steven; Golling, Tobias; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; Gonidec, Allain; Gonzalez, Saul; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Gorokhov, Serguei; Goryachev, Vladimir; Gosdzik, Bjoern; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grinstein, Sebastian; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Groh, Manfred; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guarino, Victor; Guest, Daniel; Guicheney, Christophe; Guida, Angelo; Guindon, Stefan; Guler, Hulya; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gupta, Ambreesh; Gusakov, Yury; Gushchin, Vladimir; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hackenburg, Robert; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Haider, Stefan; Hajduk, Zbigniew; Hakobyan, Hrachya; Hall, David; Haller, Johannes; Hamacher, Klaus; Hamal, Petr; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Han, Hongguang; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, John Renner; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Hare, Gabriel; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Karl; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Hatch, Mark; Hauff, Dieter; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawes, Brian; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hawkins, Donovan; Hayakawa, Takashi; Hayashi, Takayasu; Hayden, Daniel; Hayward, Helen; Haywood, Stephen; Hazen, Eric; He, Mao; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Henry-Couannier, Frédéric; Hensel, Carsten; Henß, Tobias; Medina Hernandez, Carlos; Hernández Jiménez, Yesenia; Herrberg, Ruth; Hershenhorn, Alon David; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Higón-Rodriguez, Emilio; Hill, Daniel; Hill, John; Hill, Norman; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Homma, Yasuhiro; Hong, Tae Min; Hooft van Huysduynen, Loek; Horazdovsky, Tomas; Horn, Claus; Horner, Stephan; Hostachy, Jean-Yves; Hou, Suen; Houlden, Michael; Hoummada, Abdeslam; Howarth, James; Howell, David; Hristova, Ivana; Hrivnac, Julius; Hruska, Ivan; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Huang, Guang Shun; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huettmann, Antje; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Hughes-Jones, Richard; Huhtinen, Mika; Hurst, Peter; Hurwitz, Martina; Husemann, Ulrich; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Ichimiya, Ryo; Iconomidou-Fayard, Lydia; Idarraga, John; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuri; Iliadis, Dimitrios; Ilic, Nikolina; Imori, Masatoshi; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishikawa, Akimasa; Ishino, Masaya; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakubek, Jan; Jana, Dilip; Jankowski, Ernest; Jansen, Eric; Jansen, Hendrik; Jantsch, Andreas; Janus, Michel; Jarlskog, Göran; Jeanty, Laura; Jelen, Kazimierz; Jen-La Plante, Imai; Jenni, Peter; Jeremie, Andrea; Jež, Pavel; Jézéquel, Stéphane; Jha, Manoj Kumar; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Ge; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Lars; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tegid; Jones, Tim; Jonsson, Ove; Joram, Christian; Jorge, Pedro; Joseph, John; Jovicevic, Jelena; Jovin, Tatjana; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Juranek, Vojtech; Jussel, Patrick; Juste Rozas, Aurelio; Kabachenko, Vasily; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kaiser, Steffen; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagoz, Muge; Karnevskiy, Mikhail; Karr, Kristo; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kasmi, Azzedine; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Kehoe, Robert; Keil, Markus; Kekelidze, George; Kennedy, John; Kenney, Christopher John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khakzad, Mohsen; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Kholodenko, Anatoli; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Nikolai; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Min Suk; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kirsch, Lawrence; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kittelmann, Thomas; Kiver, Andrey; Kladiva, Eduard; Klaiber-Lodewigs, Jonas; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Knecht, Neil; Kneringer, Emmerich; Knobloch, Juergen; Knoops, Edith; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Köneke, Karsten; König, Adriaan; Koenig, Sebastian; Köpke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kokott, Thomas; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Kollefrath, Michael; Kolya, Scott; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kootz, Andreas; Koperny, Stefan; Korcyl, Krzysztof; Kordas, Kostantinos; Koreshev, Victor; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotamäki, Miikka Juhani; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, James; Kraus, Jana; Kreisel, Arik; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruth, Andre; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kundu, Nikhil; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lablak, Said; Lacasta, Carlos; Lacava, Francesco; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lamanna, Massimo; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Lane, Jenna; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larionov, Anatoly; Larner, Aimee; Lasseur, Christian; Lassnig, Mario; Laurelli, Paolo; Lavorini, Vincenzo; Lavrijsen, Wim; Laycock, Paul; Lazarev, Alexandre; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Maner, Christophe; Le Menedeu, Eve; Lebel, Céline; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Leger, Annie; LeGeyt, Benjamin; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Leltchouk, Mikhail; Lemmer, Boris; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Leroy, Claude; Lessard, Jean-Raphael; Lesser, Jonas; Lester, Christopher; Leung Fook Cheong, Annabelle; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levitski, Mikhail; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Shu; Li, Xuefei; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Lifshitz, Ronen; Lilley, Joseph; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipinsky, Lukas; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Loken, James; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lo Sterzo, Francesco; Losty, Michael; Lou, Xinchou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dörthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lumb, Debra; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Björn; Lundberg, Johan; Lundquist, Johan; Lungwitz, Matthias; Lutz, Gerhard; Lynn, David; Lys, Jeremy; Lytken, Else; Ma, Hong; Ma, Lian Liang; Macana Goia, Jorge Andres; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Mackeprang, Rasmus; Madaras, Ronald; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mättig, Peter; Mättig, Stefan; Magnoni, Luca; Magradze, Erekle; Mahalalel, Yair; Mahboubi, Kambiz; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Mangeard, Pierre-Simon; Manhaes de Andrade Filho, Luciano; Manjavidze, Ioseb; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Manz, Andreas; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marin, Alexandru; Marino, Christopher; Marroquim, Fernando; Marshall, Robin; Marshall, Zach; Martens, Kalen; Marti-Garcia, Salvador; Martin, Andrew; Martin, Brian; Martin, Brian Thomas; Martin, Franck Francois; Martin, Jean-Pierre; Martin, Philippe; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martin-Haugh, Stewart; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mathes, Markus; Matricon, Pierre; Matsumoto, Hiroshi; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maugain, Jean-Marie; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; May, Edward; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzanti, Marcello; Mazzoni, Enrico; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; McGlone, Helen; Mchedlidze, Gvantsa; McLaren, Robert Andrew; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehdiyev, Rashid; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Menot, Claude; Meoni, Evelin; Mercurio, Kevin Michael; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Meyer, Thomas Christian; Meyer, W Thomas; Miao, Jiayuan; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Miralles Verge, Lluis; Misiejuk, Andrzej; Mitrevski, Jovan; Mitrofanov, Gennady; Mitsou, Vasiliki A; Mitsui, Shingo; Miyagawa, Paul; Miyazaki, Kazuki; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mockett, Paul; Moed, Shulamit; Moeller, Victoria; Mönig, Klaus; Möser, Nicolas; Mohapatra, Soumya; Mohr, Wolfgang; Mohrdieck-Möck, Susanne; Moisseev, Artemy; Moles-Valls, Regina; Molina-Perez, Jorge; Monk, James; Monnier, Emmanuel; Montesano, Simone; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Morin, Jerome; Morley, Anthony Keith; Mornacchi, Giuseppe; Morozov, Sergey; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mudrinic, Mihajlo; Mueller, Felix; Mueller, James; Mueller, Klemens; Müller, Thomas; Mueller, Timo; Muenstermann, Daniel; Muir, Alex; Munwes, Yonathan; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Nadal, Jordi; Nagai, Koichi; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Narayan, Rohin; Nash, Michael; Nation, Nigel; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nebot, Eduardo; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Silke; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen Thi Hong, Van; Nickerson, Richard; Nicolaidou, Rosy; Nicolas, Ludovic; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Niinikoski, Tapio; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolaev, Kirill; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishiyama, Tomonori; Nisius, Richard; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nordberg, Markus; Nordkvist, Bjoern; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozka, Libor; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; O'Brien, Brendan Joseph; O'Neale, Steve; O'Neil, Dugan; O'Shea, Val; Oakes, Louise Beth; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Ohshita, Hidetoshi; Ohsugi, Takashi; Okada, Shogo; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olcese, Marco; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Omachi, Chihiro; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Simon; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganis, Efstathios; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Paleari, Chiara; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panes, Boris; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Panuskova, Monika; Paolone, Vittorio; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Park, Woochun; Parker, Andy; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Peng, Haiping; Pengo, Ruggero; Penning, Bjoern; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Perez Cavalcanti, Tiago; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Persembe, Seda; Perus, Antoine; Peshekhonov, Vladimir; Peters, Krisztian; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Peter William; Piacquadio, Giacinto; Piccaro, Elisa; Piccinini, Maurizio; Piec, Sebastian Marcin; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Ping, Jialun; Pinto, Belmiro; Pirotte, Olivier; Pizio, Caterina; Placakyte, Ringaile; Plamondon, Mathieu; Pleier, Marc-Andre; Pleskach, Anatoly; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Poghosyan, Tatevik; Pohl, Martin; Polci, Francesco; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomarede, Daniel Marc; Pomeroy, Daniel; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Posch, Christoph; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Prabhu, Robindra; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Pribyl, Lukas; Price, Darren; Price, Joe; Price, Lawrence; Price, Michael John; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przybycien, Mariusz; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Pueschel, Elisa; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Qian, Zuxuan; Qin, Zhonghua; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radescu, Voica; Radics, Balint; Radloff, Peter; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rahm, David; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Randle-Conde, Aidan Sean; Randrianarivony, Koloina; Ratoff, Peter; Rauscher, Felix; Rave, Tobias Christian; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reichold, Armin; Reinherz-Aronis, Erez; Reinsch, Andreas; Reisinger, Ingo; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Renkel, Peter; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richards, Alexander; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robinson, Mary; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Rodriguez, Diego; Roe, Adam; Roe, Shaun; Røhne, Ole; Rojo, Victoria; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romanov, Victor; Romeo, Gaston; Romero Adam, Elena; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Anthony; Rose, Matthew; Rosenbaum, Gabriel; Rosenberg, Eli; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rosselet, Laurent; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexander; Rozen, Yoram; Ruan, Xifeng; Rubinskiy, Igor; Ruckert, Benjamin; Ruckstuhl, Nicole; Rud, Viacheslav; Rudolph, Christian; Rudolph, Gerald; Rühr, Frederik; Ruggieri, Federico; Ruiz-Martinez, Aranzazu; Rumiantsev, Viktor; Rumyantsev, Leonid; Runge, Kay; Rurikova, Zuzana; Rusakovich, Nikolai; Rust, Dave; Rutherfoord, John; Ruwiedel, Christoph; Ruzicka, Pavel; Ryabov, Yury; Ryadovikov, Vasily; Ryan, Patrick; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Rzaeva, Sevda; Saavedra, Aldo; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Björn Hallvard; Sanchez, Arturo; Sanchez Martinez, Victoria; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sandvoss, Stephan; Sankey, Dave; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Saraiva, João; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarri, Francesca; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Takashi; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Emmanuel; Sauvan, Jean-Baptiste; Savard, Pierre; Savinov, Vladimir; Savu, Dan Octavian; Sawyer, Lee; Saxon, David; Says, Louis-Pierre; Sbarra, Carla; Sbrizzi, Antonio; Scallon, Olivia; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schäfer, Uli; Schaepe, Steffen; Schaetzel, Sebastian; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R. Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schlereth, James; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schmitz, Martin; Schöning, André; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schroeder, Christian; Schroer, Nicolai; Schuh, Silvia; Schuler, Georges; Schultens, Martin Johannes; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Jan; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Scott, Bill; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Segura, Ester; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Seuster, Rolf; Severini, Horst; Sevior, Martin; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaver, Leif; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shibata, Akira; Shichi, Hideharu; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shiyakova, Maria; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simmons, Brinick; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Skvorodnev, Nikolai; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Sloper, John erik; Smakhtin, Vladimir; Smart, Ben; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snuverink, Jochem; Snyder, Scott; Soares, Mara; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sosebee, Mark; Soualah, Rachik; Soukharev, Andrey; Spagnolo, Stefania; Spanò, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spila, Federico; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staude, Arnold; Stavina, Pavel; Stavropoulos, Georgios; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stevenson, Kyle; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strang, Michael; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Strube, Jan; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Styles, Nicholas Adam; Soh, Dart-yin; Su, Dong; Subramania, Halasya Siva; Succurro, Antonella; Sugaya, Yorihito; Sugimoto, Takuya; Suhr, Chad; Suita, Koichi; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Sushkov, Serge; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Suzuki, Yuta; Svatos, Michal; Sviridov, Yuri; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Szeless, Balazs; Sánchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanaka, Yoshito; Tanasijczuk, Andres Jorge; Tani, Kazutoshi; Tannoury, Nancy; Tappern, Geoffrey; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tatarkhanov, Mous; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teinturier, Marthe; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Testa, Marianna; Teuscher, Richard; Thadome, Jocelyn; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thioye, Moustapha; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tic, Tomáš; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tipton, Paul; Tique Aires Viegas, Florbela De Jes; Tisserant, Sylvain; Tobias, Jürgen; Toczek, Barbara; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokunaga, Kaoru; Tokushuku, Katsuo; Tollefson, Kirsten; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tong, Guoliang; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torchiani, Ingo; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Trinh, Thi Nguyet; Tripiana, Martin; Trischuk, William; Trivedi, Arjun; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tudorache, Alexandra; Tudorache, Valentina; Tuggle, Joseph; Turala, Michal; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Underwood, David; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valenta, Jan; Valente, Paolo; Valentinetti, Sara; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; van der Graaf, Harry; van der Kraaij, Erik; Van Der Leeuw, Robin; van der Poel, Egge; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; van Kesteren, Zdenko; van Vulpen, Ivo; Vanadia, Marco; Vandelli, Wainer; Vandoni, Giovanna; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Varela Rodriguez, Fernando; Vari, Riccardo; Varnes, Erich; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vegni, Guido; Veillet, Jean-Jacques; Vellidis, Constantine; Veloso, Filipe; Veness, Raymond; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Virchaux, Marc; Virzi, Joseph; Vitells, Ofer; Viti, Michele; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vlasov, Nikolai; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Loeben, Joerg; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobiev, Alexander; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Voss, Thorsten Tobias; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wakabayashi, Jun; Walbersloh, Jorg; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Wang, Chiho; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Joshua C; Wang, Rui; Wang, Song-Ming; Warburton, Andreas; Ward, Patricia; Warsinsky, Markus; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Marc; Weber, Michele; Weber, Pavel; Weidberg, Anthony; Weigell, Philipp; Weingarten, Jens; Weiser, Christian; Wellenstein, Hermann; Wells, Phillippa; Wen, Mei; Wenaus, Torre; Wendland, Dennis; Wendler, Shanti; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Weydert, Carole; Whalen, Kathleen; Wheeler-Ellis, Sarah Jane; Whitaker, Scott; White, Andrew; White, Martin; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilhelm, Ivan; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Eric; Williams, Hugh; Willis, William; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wong, Wei-Cheng; Wooden, Gemma; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wraight, Kenneth; Wright, Catherine; Wright, Michael; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wunstorf, Renate; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xie, Song; Xie, Yigang; Xu, Chao; Xu, Da; Xu, Guofa; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamaoka, Jared; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Un-Ki; Yang, Yi; Yang, Yi; Yang, Zhaoyu; Yanush, Serguei; Yao, Yushu; Yasu, Yoshiji; Ybeles Smit, Gabriel Valentijn; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Riktura; Young, Charles; Youssef, Saul; Yu, Dantong; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zabinski, Bartlomiej; Zaets, Vassilli; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zanello, Lucia; Zarzhitsky, Pavel; Zaytsev, Alexander; Zeitnitz, Christian; Zeller, Michael; Zeman, Martin; Zemla, Andrzej; Zendler, Carolin; Zenin, Oleg; Ženiš, Tibor; Zenonos, Zenonas; Zenz, Seth; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhan, Zhichao; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Tianchi; Zhao, Zhengguo; Zhemchugov, Alexey; Zheng, Shuchen; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zieminska, Daria; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zitoun, Robert; Živković, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; Zolnierowski, Yves; Zsenei, Andras; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz

2013-03-02

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of $\\sqrt{s}$ = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.

Study of Drell-Yan process in CMS experiment at Large Hadron Collider

CERN Document Server

Jindal, Monika

The proton-proton collisions at the Large Hadron Collider (LHC) is the begining of a new era in the high energy physics. It enables the possibility of the discoveries at high-energy frontier and also allows the study of Standard Model physics with high precision. The new physics discoveries and the precision measurements can be achieved with highly efficient and accurate detectors like Compact Muon Solenoid. In this thesis, we report the measurement of the differential production cross-section of the Drell-Yan process, $q ar{q} ightarrow Z/gamma^{*} ightarrowmu^{+}mu^{-}$ in proton-proton collisions at the center-of-mass energy $sqrt{s}=$ 7 TeV using CMS experiment at the LHC. This measurement is based on the analysis of data which corresponds to an integrated luminosity of $intmath{L}dt$ = 36.0 $pm$ 1.4 pb$^{-1}$. The measurement of the production cross-section of the Drell-Yan process provides a first test of the Standard Model in a new energy domain and may reveal exotic physics processes. The Drell...

Femtoscopic analysis of hadron-hadron correlations in ultrarelativistic collisions of protons and heavy-ions registered by ALICE at the LHC

CERN Document Server

Graczykowski, Łukasz Kamil

One of the most powerful methods developed to probe the properties of the Quark-Gluon Plasma (QGP) is the technique of two-particle correlations in momentum space, called \\emph{femtoscopy}. Femtoscopy gives the unique possibility to measure the space-time evolution of the system created in particle collisions. It is capable of measuring space scales of the order of femtometers ($10^{-15}$~m; the size of a nucleon), as well as times of the order of $10^{-23}$~s. In heavy-ion collisions it provides insight into the collective effects exhibited by the created bulk strongly coupled matter. Intriguing results from the analysis of the p--Pb collisions at the Large Hadron Collider (LHC) suggest that collective properties could also develop in small systems after all. First studies of the p--Pb system, which was initially expected to serve as a control measurement, assuming no formation of a QGP state, show that particularly at the extreme energies at the LHC, more complex physics mechanisms maybe involved, interes...

Tolerable systematic errors in Really Large Hadron Collider dipoles

International Nuclear Information System (INIS)

Peggs, S.; Dell, F.

1996-01-01

Maximum allowable systematic harmonics for arc dipoles in a Really Large Hadron Collider are derived. The possibility of half cell lengths much greater than 100 meters is justified. A convenient analytical model evaluating horizontal tune shifts is developed, and tested against a sample high field collider

High precision tools for slepton pair production processes at hadron colliders

International Nuclear Information System (INIS)

Thier, Stephan Christoph

2015-01-01

In this thesis, we develop high precision tools for the simulation of slepton pair production processes at hadron colliders and apply them to phenomenological studies at the LHC. Our approach is based on the POWHEG method for the matching of next-to-leading order results in perturbation theory to parton showers. We calculate matrix elements for slepton pair production and for the production of a slepton pair in association with a jet perturbatively at next-to-leading order in supersymmetric quantum chromodynamics. Both processes are subsequently implemented in the POWHEG BOX, a publicly available software tool that contains general parts of the POWHEG matching scheme. We investigate phenomenological consequences of our calculations in several setups that respect experimental exclusion limits for supersymmetric particles and provide precise predictions for slepton signatures at the LHC. The inclusion of QCD emissions in the partonic matrix elements allows for an accurate description of hard jets. Interfacing our codes to the multi-purpose Monte-Carlo event generator PYTHIA, we simulate parton showers and slepton decays in fully exclusive events. Advanced kinematical variables and specific search strategies are examined as means for slepton discovery in experimentally challenging setups.

Hadronic cross-sections in two photon processes at a future linear collider

International Nuclear Information System (INIS)

Godbole, Rohini M.; Roeck, Albert de; Grau, Agnes; Pancheri, Giulia

2003-01-01

In this note we address the issue of measurability of the hadronic cross-sections at a future photon collider as well as for the two-photon processes at a future high energy linear e + e - collider. We extend, to higher energy, our previous estimates of the accuracy with which the γ γ cross-section needs to be measured, in order to distinguish between different theoretical models of energy dependence of the total cross-sections. We show that the necessary precision to discriminate among these models is indeed possible at future linear colliders in the Photon Collider option. Further we note that even in the e + e - option a measurement of the hadron production cross-section via γ γ processes, with an accuracy necessary to allow discrimination between different theoretical models, should be possible. We also comment briefly on the implications of these predictions for hadronic backgrounds at the future TeV energy e + e - collider CLIC. (author)

Hadron Collider Physics with Real Time Trajectory Reconstruction

Energy Technology Data Exchange (ETDEWEB)

Annovi, Alberto [Univ. of Pisa (Italy)

2005-01-01

During last century experiments with accelerators have been extensively used to improve our understanding of matter. They are now the most common tool used to search for new phenomena in high energy physics. In the process of probing smaller distances and searching for new particles the center of mass energy has been steadily increased. The need for higher center of mass energy made hadron colliders the natural tool for discovery physics. Hadron colliders have a major drawback with respect to electron-positron colliders. As shown in fig. 1 the total cross section is several orders of magnitude larger than the cross section of interesting processes such as top or Higgs production. This means that, in order to observe interesting processes, it’s necessary to have collisions at very high rates and it becomes necessary to reject on-line most of the “non-interesting” events. In this thesis I have described the wide range of SVT applications within CDF.

Operational Experience and Consolidations for the Current Lead Control Valves of the Large Hadron Collider

CERN Document Server

Perin, A; Pirotte, O; Krieger, B; Widmer, A

2012-01-01

The Large Hadron Collider superconducting magnets are powered by more than 1400 gas cooled current leads ranging from 120 A to 13000 A. The gas flow required by the leads is controlled by solenoid proportional valves with dimensions from DN 1.8 mm to DN 10 mm. During the first months of operation, signs of premature wear were found in the active parts of the valves. This created major problems for the functioning of the current leads threatening the availability of the LHC. Following the detection of the problems, a series of measures were implemented to keep the LHC running, to launch a development program to solve the premature wear problem and to prepare for a global consolidation of the gas flow control system. This article describes first the difficulties encountered and the measures taken to ensure a continuous operation of the LHC during the first year of operation. The development of new friction free valves is then presented along with the consolidation program and the test equipment developed to val...

Development of Muon Drift-Tube Detectors for High-Luminosity Upgrades of the Large Hadron Collider

CERN Document Server

Bittner, B; Kortner, O.; Kroha, H.; Legger, F.; Richter, R.; Biebel, O.; Engl, A.; Hertenberger, R.; Rauscher, F.

2016-01-01

The muon detectors of the experiments at the Large Hadron Collider (LHC) have to cope with unprecedentedly high neutron and gamma ray background rates. In the forward regions of the muon spectrometer of the ATLAS detector, for instance, counting rates of 1.7 kHz/square cm are reached at the LHC design luminosity. For high-luminosity upgrades of the LHC, up to 10 times higher background rates are expected which require replacement of the muon chambers in the critical detector regions. Tests at the CERN Gamma Irradiation Facility showed that drift-tube detectors with 15 mm diameter aluminum tubes operated with Ar:CO2 (93:7) gas at 3 bar and a maximum drift time of about 200 ns provide e?cient and high-resolution muon tracking up to the highest expected rates. For 15 mm tube diameter, space charge e?ects deteriorating the spatial resolution at high rates are strongly suppressed. The sense wires have to be positioned in the chamber with an accuracy of better than 50 ?micons in order to achieve the desired spatial...

Current and expected performance of tracking and vertexing with the ATLAS detector at the LHC and the HL-LHC.

CERN Document Server

Kastanas, Alex; The ATLAS collaboration

2018-01-01

The ATLAS detector at the Large Hadron Collider (LHC) has had an extremely successful data collecting period during 2017, recording over 45 fb-1 of proton-proton collision data at sqrt(s) = 13 TeV. This was achieved, in part, by running the LHC at a high instantaneous lumi- nosity level of over 1.5 x 10+34 cm-2s-1, which corresponds to over 57 inelastic proton-proton collisions per beam crossing. This talk will highlight the tracking and vertexing performance of the tracking detector within ATLAS (Inner Detector) throughout this successful year of data taking. In order to increase its potential for discoveries, the High Luminosity Large Hadron Collider (HL-LHC) aims to increase the LHC data-set by an order of magnitude by collecting 3,000 fb-1 of recorded data. Starting, from mid-2026, the HL-LHC is expected to reach the peak instantaneous luminosity of 7.5 x 10+34 cm-2s-1, which corresponds to about 200 inelastic proton-proton collisions per beam crossing. To cope with the large radiation doses and high pile...

LHC-ILC synergy

CERN Document Server

Godbole, Rohini M

2006-01-01

I will begin by making a few general comments on the synergy between the Large Hadron Collider (LHC) which will go in action in 2007 and the International Linear Collider (ILC) which is under planning. I will then focus on the synergy between the LHC and the PLC option at the ILC, which is expected to be realised in the later stages of the ILC program. In this I will cover the possible synergy in the Higgs sector (with and without CP violation), in the determination of the anomalous vector boson couplings and last but not the least, in the search for extra dimensions and radions.

The LHC detector challenge

CERN Document Server

Virdee, Tejinder S

2004-01-01

The Large Hadron Collider (LHC) from CERN, scheduled to come online in 2007, is a multi-TeV proton-proton collider with vast detectors. Two of the more significant detectors for LHC are ATLAS and CMS. Currently, both detectors are more than 65% complete in terms of financial commitment, and the experiments are being assembled at an increasing pace. ATLAS is being built directly in its underground cavern, whereas CMS is being assembled above ground. When completed, both detectors will aid researchers in determining what lies at the high-energy frontier, in particular the mechanism by which particles attain mass. (Edited abstract).

A study of parton fragmentation using photon-hadron correlation with the ALICE experiment at LHC

International Nuclear Information System (INIS)

Arbor, N.

2013-01-01

The strong interaction theory, Quantum Chromodynamic (QCD), predicts a new phase of nuclear matter at very high temperature and/or very high density. This state is composed of deconfined quarks and gluons known as the quark-gluon plasma (QGP). The measurement of its composition and properties is a challenge for the nuclear physics of the 21. century and should lead to a better understanding of the fundamental symmetries and mechanisms related to the quarks confinement inside hadrons and the strong interaction generally.The Large Hadron Collider (LHC) accelerator at CERN (European Organization for Nuclear Research) allows to reach the thermodynamic conditions required to create the quark-gluon plasma using ultra-relativistic heavy ion collisions (Pb). The ALICE experiment (A Large Ion Collider Experiment) allows to access several probes to characterize the QGP through particles reconstruction and. Among these probes, high energy parton energy loss is used to access medium characteristics such as density or temperature. Parton energy loss is estimated from the modification of the energy distribution of hadrons produced by fragmentation.This thesis is dedicated to the photon-hadron correlations analysis in order to study the modification of the parton fragmentation due to the quark-gluon plasma. First part of this thesis is devoted to the characterization of the electromagnetic calorimeter (EMCal), the central detector for energy measurement and photon identification. The second part is dedicated to the photon-hadron correlation measurement, for the 7 TeV proton-proton collisions and 2.76 TeV Lead-Lead collisions. An important work has been done to improve the prompt photon identification, one of the key point of this analysis. (author) [fr

A study of parton fragmentation using photon-hadron correlation with the ALICE experiment at LHC

International Nuclear Information System (INIS)

Arbor, Nicolas

2013-01-01

The strong interaction theory, Quantum Chromodynamic (QCD), predicts a new phase of nuclear matter at very high temperature and/or very high density. This state is composed of deconfined quarks and gluons known as the quark-gluon plasma (QGP). The measurement of its composition and properties is a challenge for the nuclear physics of the 21. century and should lead to a better understanding of the fundamental symmetries and mechanisms related to the quarks confinement inside hadrons and the strong interaction generally. The Large Hadron Collider (LHC) accelerator at CERN (European Organization for Nuclear Research) allows to reach the thermodynamic conditions required to create the quark-gluon plasma using ultra-relativistic heavy ion collisions (Pb). The ALICE experiment (A Large Ion Collider Experiment) allows to access several probes to characterize the QGP through particles reconstruction and. Among these probes, high energy parton energy loss is used to access medium characteristics such as density or temperature. Parton energy loss is estimated from the modification of the energy distribution of hadrons produced by fragmentation. This thesis is dedicated to the photon-hadron correlations analysis in order to study the modification of the parton fragmentation due to the quark-gluon plasma. First part of this thesis is devoted to the characterization of the electromagnetic calorimeter (EMCal), the central detector for energy measurement and photon identification. The second part is dedicated to the photon-hadron correlation measurement, for the 7 TeV proton-proton collisions and 2.76 TeV Lead-Lead collisions. An important work has been done to improve the prompt photon identification, one of the key point of this analysis. (author) [fr

Development of N+ in P pixel sensors for a high-luminosity large hadron collider

Science.gov (United States)

Kamada, Shintaro; Yamamura, Kazuhisa; Unno, Yoshinobu; Ikegami, Yoichi

2014-11-01

Hamamatsu Photonics K. K. is developing an N+ in a p planar pixel sensor with high radiation tolerance for the high-luminosity large hadron collider (HL-LHC). The N+ in the p planar pixel sensor is a candidate for the HL-LHC and offers the advantages of high radiation tolerance at a reasonable price compared with the N+ in an n planar sensor, the three-dimensional sensor, and the diamond sensor. However, the N+ in the p planar pixel sensor still presents some problems that need to be solved, such as its slim edge and the danger of sparks between the sensor and readout integrated circuit. We are now attempting to solve these problems with wafer-level processes, which is important for mass production. To date, we have obtained a 250-μm edge with an applied bias voltage of 1000 V. To protect against high-voltage sparks from the edge, we suggest some possible designs for the N+ edge.

Model-independent description and Large Hadron Collider implications of suppressed two-photon decay of a light Higgs boson

International Nuclear Information System (INIS)

Phalen, Daniel J.; Thomas, Brooks; Wells, James D.

2007-01-01

For a standard model Higgs boson with mass between 115 GeV and 150 GeV, the two-photon decay mode is important for discovery at the Large Hadron Collider (LHC). We describe the interactions of a light Higgs boson in a more model-independent fashion and consider the parameter space where there is no two-photon decay mode. We argue from generalities that analysis of the tth discovery mode outside its normal thought of range of applicability is especially needed under these circumstances. We demonstrate the general conclusion with a specific example of parameters of a type I two-Higgs doublet theory, motivated by ideas in strongly coupled model building. We then specify a complete set of branching fractions and discuss the implications for the LHC

Robert Aymar seals the last interconnect in the LHC

CERN Multimedia

Maximilien Brice

2007-01-01

The LHC completes the circle. On 7 November, in a brief ceremony in the LHC tunnel, CERN Director General Robert Aymar (Photo 1) sealed the last interconnect between the main magnets of the Large Hadron Collider (LHC). Jean-Philippe Tock, leader of the Interconnections team, tightens the last bolt (Photos 4-8).

Hadron production of Majorana neutrinos at VLHC energies

International Nuclear Information System (INIS)

Almeida Junior, F.M.L. de; Coutinho, Y.A.; Martins Simoes, J.A.; Vale, M.A.B. do

2003-01-01

The Very Large Hadron Collider (VLHC) is being proposed as a 50+50 TeV hadron collider to extend the energy frontier beyond the LHC. Since 1998-1999 the option of a ep collider operating with the 3 TeV proton booster has been considered. This design uses a 80 GeV electron beam to produce ep collisions with a luminosity of 2600 Pb-1/yr with a center of mass energy of 1 TeV. We study the discovery potential of this proposed ep collider for detecting new neutral heavy Majorana leptons suggested by different extensions of the Standard Model, using the channel e - p →e + = jets. (author)

Strategy and issues for the LHC upgrades and fair, including longer-term prospects

CERN Document Server

Zimmermann, F

2013-01-01

This report discusses the time line, goals and key ingredients for the next ten years of LHC operation, including injector upgrade, for the following High Luminosity LHC (HL-LHC), and for the FAIR project. Results from pertinent EuCARD-WP4 workshops on optics, space charge, crab cavities, crystal collimation, and electron cloud are summarized in this context. A Large Hadron electron Collider, LHeC, would be an additional upgrade, further expanding the physics scope of the LHC, to eventually include both ep and γγ Higgs factories (LHeC-HF and SAPPHiRE). Results from relevant topical WP4 workshops are highlighted. The development of magnet and cable technology based on Nb$_{3}$Sn, and HTS, for the HL-LHC prepares the ground for a future higher-energy hadron collider, either in the LHC tunnel, “HELHC” (33 TeV c.m.), or in a new 80- or 100-km tunnel, “VHE-LHC” (100 TeV c.m.). A large new tunnel could also host an ultimate highest-precision e+e- Higgs factory collider, “TLEP,” exhibiting many synergi...

Calculation of abort thresholds for the Beam Loss Monitoring System of the Large Hadron Collider at CERN

CERN Document Server

Nemcic, Martin; Dehning, Bernd

The Beam Loss Monitoring (BLM) System is one of the most critical machine protection systems for the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN), Switzerland. Its main purpose is to protect the superconducting magnets from quenches and other equipment from damage by requesting a beam abort when the measured losses exceed any of the predefined threshold levels. The system consist of circa 4000 ionization chambers which are installed around the 27 kilometres ring (LHC). This study aims to choose a technical platform and produce a system that addresses all of the limitations with the current system that is used for the calculation of the LHC BLM abort threshold values. To achieve this, a comparison and benchmarking of the Java and .NET technical platforms is performed in order to establish the most suitable solution. To establish which technical platform is a successful replacement of the current abort threshold calculator, comparable prototype systems in Java and .NET we...

A Novel Method and Error Analysis for Beam Optics Measurements and Corrections at the Large Hadron Collider

CERN Document Server

Langner, Andy Sven; Rossbach, Jörg; Tomás, Rogelio

2017-02-17

The Large Hadron Collider (LHC) is currently the world's largest particle accelerator with the highest center of mass energy in particle collision experiments. The control of the particle beam focusing is essential for the performance reach of such an accelerator. For the characterization of the focusing properties at the LHC, turn-by-turn beam position data is simultaneously recorded at numerous measurement devices (BPMs) along the accelerator, while an oscillation is excited on the beam. A novel analysis method for these measurements ($N$-BPM method) is developed here, which is based on a detailed analysis of systematic and statistical error sources and their correlations. It has been applied during the commissioning of the LHC for operation at an unprecedented energy of 6.5 TeV. In this process a stronger focusing than its design specifications has been achieved. This results in smaller transverse beam sizes at the collision points and allows for a higher rate of particle collisions. For the derivation of ...

Monotop phenomenology at the Large Hadron Collider

CERN Document Server

Agram, Jean-Laurent; Buttignol, Michael; Conte, Eric; Fuks, Benjamin

2014-01-01

We investigate new physics scenarios where systems comprised of a single top quark accompanied by missing transverse energy, dubbed monotops, can be produced at the LHC. Following a simplified model approach, we describe all possible monotop production modes via an effective theory and estimate the sensitivity of the LHC, assuming 20 fb$^{-1}$ of collisions at a center-of-mass energy of 8 TeV, to the observation of a monotop state. Considering both leptonic and hadronic top quark decays, we show that large fractions of the parameter space are reachable and that new physics particles with masses ranging up to 1.5 TeV can leave hints within the 2012 LHC dataset, assuming moderate new physics coupling strengths.

TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

Energy Technology Data Exchange (ETDEWEB)

Jabeen, Shabnam

2013-10-20

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

HL-LHC alternatives

CERN Document Server

Tomás, R; White, S

2014-01-01

The HL-LHC parameters assume unexplored regimes for hadron colliders in various aspects of accelerator beam dynamics and technology. This paper reviews three alternatives that could potentially improve the LHC performance: (i) the alternative filling scheme 8b+4e, (ii) the use of a 200 MHz RF system in the LHC and (iii) the use of proton cooling methods to reduce the beam emittance (at top energy and at injection). The alternatives are assessed in terms of feasibility, pros and cons, risks versus benefits and the impact on beam availability.

Working group report: Physics at the Large Hadron Collider

Indian Academy of Sciences (India)

cally viable physics issues at two hadron colliders currently under operation, the p¯p collider ... corrections to different SM processes are very important. ... Keeping all these in mind and the available skills and interests of the ... relation involving the masses of the Standard Model particles as well as the masses of any.

High luminosity electron-hadron collider eRHIC

Energy Technology Data Exchange (ETDEWEB)

Ptitsyn, V.; Aschenauer, E.; Bai, M.; Beebe-Wang, J.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M..; Calaga, R.; Chang, X.; Fedotov, A.; Gassner, D.; Hammons, L.; Hahn, H.; Hammons, L.; He, P.; Hao, Y.; Jackson, W.; Jain, A.; Johnson, E.C.; Kayran, D.; Kewisch, J.; Litvinenko, V.N.; Luo, Y.; Mahler, G.; McIntyre, G.; Meng, W.; Minty, M.; Parker, B.; Pikin, A.; Rao, T.; Roser, T.; Skaritka, J.; Sheehy, B.; Skaritka, J.; Tepikian, S.; Than, Y.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Webb, S.; Wu, Q.; Xu, W.; Pozdeyev, E.; Tsentalovich, E.

2011-03-28

We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10{sup 34} cm{sup -2} s{sup -1} can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling, ERL test facility and the compact magnets for recirculation passes. A natural staging scenario of step-by-step increases of the electron beam energy by building-up of eRHIC's SRF linacs is presented.

Search for excited electrons using the CMS detector at the Large Hadron Collider

International Nuclear Information System (INIS)

Jain, Shilpi

2013-01-01

The start of the Large Hadron Collider (LHC) opened a new window to the energy scale far beyond 1 TeV. There are different theories that predict new physics, and hence it is not clear what signature to expect in the data and which of the theory will describe it properly. However new physics could as well manifest itself in ways no one has yet thought of. Thus we have implemented a Model Unspecific Search in CMS (MUSiC). This approach has been applied to the CMS data and we have obtained the preliminary results. I will talk about this details of the analysis techniques, its implementation in analysing CMS data, results obtained and the discussion on the discrepancy observed

Commissioning of the LHC

CERN Multimedia

CERN. Geneva

2007-01-01

The LHC construction is now approaching the end and it is now time to prepare for commissioning with beam. The behavior of a proton storage ring is much different to that of LEP, which profited from strong radiation damping to keep the beam stable. Our last experience with a hadron collider at CERN goes back more than 15 years when the proton-antiproton collider last operated. Ppbar taught us a lot about the machine physics of bunched beam proton storage rings and was essential input for the design of the LHC. After a short presentation of where we stand today with machine installation and hardware commissioning, I will discuss the main machine physics issues that will have to be dealt with in the LHC.

Tracking detectors for the sLHC, the LHC upgrade

CERN Document Server

Sadrozinski, Hartmut F W

2005-01-01

The plans for an upgrade of the Large Hadron Collider (LHC) to the Super-LHC (sLHC) are reviewed with special consideration of the environment for the inner tracking system. A straw-man detector upgrade for ATLAS is presented, which is motivated by the varying radiation levels as a function of radius, and choices for detector geometries and technologies are proposed, based on the environmental constraints. A few promising technologies for detectors are discussed, both for sensors and for the associated front-end electronics. On-going research in silicon detectors and in ASIC technologies will be crucial for the success of the upgrade.

Al CERN prima fase sistema gestione dati LHC

CERN Multimedia

2003-01-01

"Al via la prima fase per la realizzazione del sistema Lhc computing Grid (LCG), progettato per elaborare le quantita' di dati senza precedenti che, a partire dal 2007, saranno prodotte dagli esperimenti eseguiti con il nuovo grande acceleratore Large Hadron Collider (LHC), presso il Cern di Ginevra" 1 page

Thermomechanical response of Large Hadron Collider collimators to proton and ion beam impacts

Directory of Open Access Journals (Sweden)

Marija Cauchi

2015-04-01

Full Text Available The CERN Large Hadron Collider (LHC is designed to accelerate and bring into collision high-energy protons as well as heavy ions. Accidents involving direct beam impacts on collimators can happen in both cases. The LHC collimation system is designed to handle the demanding requirements of high-intensity proton beams. Although proton beams have 100 times higher beam power than the nominal LHC lead ion beams, specific problems might arise in case of ion losses due to different particle-collimator interaction mechanisms when compared to protons. This paper investigates and compares direct ion and proton beam impacts on collimators, in particular tertiary collimators (TCTs, made of the tungsten heavy alloy INERMET® 180. Recent measurements of the mechanical behavior of this alloy under static and dynamic loading conditions at different temperatures have been done and used for realistic estimates of the collimator response to beam impact. Using these new measurements, a numerical finite element method (FEM approach is presented in this paper. Sequential fast-transient thermostructural analyses are performed in the elastic-plastic domain in order to evaluate and compare the thermomechanical response of TCTs in case of critical beam load cases involving proton and heavy ion beam impacts.

Fundamental cavity impedance and longitudinal coupled-bunch instabilities at the High Luminosity Large Hadron Collider

Directory of Open Access Journals (Sweden)

P. Baudrenghien

2017-01-01

Full Text Available The interaction between beam dynamics and the radio frequency (rf station in circular colliders is complex and can lead to longitudinal coupled-bunch instabilities at high beam currents. The excitation of the cavity higher order modes is traditionally damped using passive devices. But the wakefield developed at the cavity fundamental frequency falls in the frequency range of the rf power system and can, in theory, be compensated by modulating the generator drive. Such a regulation is the responsibility of the low-level rf (llrf system that measures the cavity field (or beam current and generates the rf power drive. The Large Hadron Collider (LHC rf was designed for the nominal LHC parameter of 0.55 A DC beam current. At 7 TeV the synchrotron radiation damping time is 13 hours. Damping of the instability growth rates due to the cavity fundamental (400.789 MHz can only come from the synchrotron tune spread (Landau damping and will be very small (time constant in the order of 0.1 s. In this work, the ability of the present llrf compensation to prevent coupled-bunch instabilities with the planned high luminosity LHC (HiLumi LHC doubling of the beam current to 1.1 A DC is investigated. The paper conclusions are based on the measured performances of the present llrf system. Models of the rf and llrf systems were developed at the LHC start-up. Following comparisons with measurements, the system was parametrized using these models. The parametric model then provides a more realistic estimation of the instability growth rates than an ideal model of the rf blocks. With this modeling approach, the key rf settings can be varied around their set value allowing for a sensitivity analysis (growth rate sensitivity to rf and llrf parameters. Finally, preliminary measurements from the LHC at 0.44 A DC are presented to support the conclusions of this work.

Final implementation, commissioning, and performance of embedded collimator beam position monitors in the Large Hadron Collider

Directory of Open Access Journals (Sweden)

Gianluca Valentino

2017-08-01

Full Text Available During Long Shutdown 1, 18 Large Hadron Collider (LHC collimators were replaced with a new design, in which beam position monitor (BPM pick-up buttons are embedded in the collimator jaws. The BPMs provide a direct measurement of the beam orbit at the collimators, and therefore can be used to align the collimators more quickly than using the standard technique which relies on feedback from beam losses. Online orbit measurements also allow for reducing operational margins in the collimation hierarchy placed specifically to cater for unknown orbit drifts, therefore decreasing the β^{*} and increasing the luminosity reach of the LHC. In this paper, the results from the commissioning of the embedded BPMs in the LHC are presented. The data acquisition and control software architectures are reviewed. A comparison with the standard alignment technique is provided, together with a fill-to-fill analysis of the measured orbit in different machine modes, which will also be used to determine suitable beam interlocks for a tighter collimation hierarchy.

\\psi (2S) enhancement in p-Pb collision as an indication of quark-gluon plasma formation at the Large Hadron Collider

Science.gov (United States)

Ganesh, S.; Singh, R., Captain; Mishra, M.

2018-03-01

Proton-nucleus collisions serve as an important baseline for the understanding and interpretation of the nucleus-nucleus collisions. These collisions have been employed to characterize the cold nuclear matter effects at SPS and Relativistic Heavy-Ion Collider energies for the past several years, as it was thought that quark-gluon plasma (QGP) is not formed in such collisions. However, at the Large Hadron Collider (LHC), there seems a possibility that QGP is formed during proton-lead (p-Pb) collisions. In this work, we have derived an expression for gluon induced excitation of J/\\psi to \\psi (2S), using pNRQCD, and show that the relative enhancement of \\psi (2S) vis-à-vis J/\\psi , especially at high p T , gives further indication that the QGP is indeed formed in p-Pb collisions at the most central collisions at LHC energy. J/\\psi and \\psi (2S) suppression effects seen at ALICE are also qualitatively explained.

LHC magnet string in 1994

CERN Multimedia

1994-01-01

On 6-7 December 1994, a string of powerful superconducting magnets for CERN's next particle accelerator, the Large Hadron Collider (LHC), ran successfully at 8.36 tesla for 24 hours. This magnetic field is 100 000 times that of the Earth and is required to keep beams of protons travelling on the correct circular path over 27 km at 7 TeV in the new LHC accelerator.

Higgs Boson and the Large Hadron Collider

International Nuclear Information System (INIS)

Banerjee, Sunanda

2014-01-01

The Standard Model of particle physics has been extremely successful in explaining all the precision data collected during the past few decades. The model, however, was incomplete with one of the key particles still not experimentally observed till 2012. This particle is predicted by the theory in the context of providing mass to the fundamental constituents as well as the exchange particles W and Z bosons. In the recent past, two experiments, ATLAS and CMS operating at the Large Hadron Collider, CERN have observed the evidence of a new state. Search signal of this object has been motivated by the Higgs boson within the Standard Model. These results have been consolidated with newer data and some attempt has gone to determine some of the properties of this newly observed state. Some of the most important recent results in this context are presented in this lecture. Several groups from India have participated in the LHC program and contributed to various aspects like the machine, computing grid and the experiments. In particular, 3 institutes and 2 University groups have been a member of the CMS collaboration and took part in the discovery of the new state. The participation of the Indian groups are also highlighted. (author)

Extra dimension searches at hadron colliders to next-to-leading order-QCD

Science.gov (United States)

Kumar, M. C.; Mathews, Prakash; Ravindran, V.

2007-11-01

The quantitative impact of NLO-QCD corrections for searches of large and warped extra dimensions at hadron colliders are investigated for the Drell-Yan process. The K-factor for various observables at hadron colliders are presented. Factorisation, renormalisation scale dependence and uncertainties due to various parton distribution functions are studied. Uncertainties arising from the error on experimental data are estimated using the MRST parton distribution functions.

Performance Analysis of the Ironless Inductive Position Sensor in the Large Hadron Collider Collimators Environment

CERN Document Server

Danisi, Alessandro; Losito, Roberto

2015-01-01

The Ironless Inductive Position Sensor (I2PS) has been introduced as a valid alternative to Linear Variable Differential Transformers (LVDTs) when external magnetic fields are present. Potential applications of this linear position sensor can be found in critical systems such as nuclear plants, tokamaks, satellites and particle accelerators. This paper analyzes the performance of the I2PS in the harsh environment of the collimators of the Large Hadron Collider (LHC), where position uncertainties of less than 20 μm are demanded in the presence of nuclear radiation and external magnetic fields. The I2PS has been targeted for installation for LHC Run 2, in order to solve the magnetic interference problem which standard LVDTs are experiencing. The paper describes in detail the chain of systems which belong to the new I2PS measurement task, their impact on the sensor performance and their possible further optimization. The I2PS performance is analyzed evaluating the position uncertainty (on 30 s), the magnetic im...

Simulation study of electron cloud induced instabilities and emittance growth for the CERN Large Hadron Collider proton beam

CERN Document Server

Benedetto, Elena; Schulte, Daniel; Rumolo, Giovanni

2005-01-01

The electron cloud may cause transverse single-bunch instabilities of proton beams such as those in the Large Hadron Collider (LHC) and the CERN Super Proton Synchrotron (SPS). We simulate these instabilities and the consequent emittance growth with the code HEADTAIL, which models the turn-by-turn interaction between the cloud and the beam. Recently some new features were added to the code, in particular, electric conducting boundary conditions at the chamber wall, transverse feedback, and variable beta functions. The sensitivity to several numerical parameters has been studied by varying the number of interaction points between the bunch and the cloud, the phase advance between them, and the number of macroparticles used to represent the protons and the electrons. We present simulation results for both LHC at injection and SPS with LHC-type beam, for different electron-cloud density levels, chromaticities, and bunch intensities. Two regimes with qualitatively different emittance growth are observed: above th...

Cryosorption pumping of residual gas in the hadron supercolliders

International Nuclear Information System (INIS)

Dostovalov, R.V.; Krasnov, A.A.

2005-01-01

In the projects of modern hadron supercollider, for example in Large Hadron Collider (LHC), the basic part of vacuum chamber will be placed inside the cryogenic elements. The LHC vacuum chamber will have a beam screen at temperature 5-20 K to protect a cold bore against the synchrotron radiation (SR) secondary electrons and image current power, and to reduce the dynamic pressure in vacuum chamber irradiated with SR. The basic results of complex study of vacuum parameters of beam screen for LHC with perspective carbon based cryosorbers (active charcoal, woven and nonwoven carbon fiber fabric) are presented in this paper [ru

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

Directory of Open Access Journals (Sweden)

Nicholas Sammut

2006-01-01

Full Text Available 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.

Processes with weak gauge boson pairs at hadron colliders. Precise predictions and future prospects

Energy Technology Data Exchange (ETDEWEB)

Salfelder, Lukas

2017-02-08

In the last years, scattering processes comprising pairs of the massive weak gauge bosons gain more and more attention. Those reactions provide particularly promising means to investigate the very mechanism responsible for electroweak symmetry breaking in the Standard Model of particle physics and to search for new physics entering via the weak sector of the theory. Precisely predicting the differential distributions of the final-state particles in realistic conditions is an essential prerequisite to potentially reveal tiny deviations induced by physics beyond the Standard Model. In this thesis we present a calculation of the next-to-leading order (NLO) electroweak corrections to W-boson pair production at CERNs Large Hadron Collider (LHC), as well as a detailed analysis of vector-boson scattering (VBS) processes at a future high-energy proton.proton collider. In particular, our calculation of the NLO electroweak corrections to the hadronic process pp→W{sup +}W{sup -}→4 leptons takes the leptonic W-boson decays as well as all off-shell effects fully into account and, thus, is the first prediction providing NLO accuracy everywhere in phase space. Employing realistic event selection criteria, we study the influence of the corrections in situations that are typical for the experimental analyses in the high-energy region and for Higgs-boson precision studies in the channel H→WW{sup *}, to which direct W-boson pair production represents an important irreducible background. We observe non-trivial distortions of the differential distributions that, if not properly included in upcoming analyses, could easily be misidentified as first signs of new physics. Furthermore, we compare our predictions to previous results obtained by employing the so-called double-pole approximation. At small and intermediate scales the two approaches show the expected agreement at the level of fractions of a percent, while in the TeV range the differences may easily reach several tens of

Leptonic signals from off-shell Z boson pairs at hadron colliders

International Nuclear Information System (INIS)

Zecher, C.; Matsuura, T.; Bij, J.J. van der

1994-04-01

We study the gluon fusion into pairs of off-shell Z bosons and their subsequent decay into charged lepton pairs at hadron colliders : g→ZZ→4l ± (l ± :charged lepton). Throughout this paper we do not restrict the intermediate state Z bosons to the narrow width approximation but allow for arbitrary invariant masses. We compare the strength of this process with the known leading order results for q anti q→ZZ→4l ± and for gg→H→ZZ→4l ± . At LHC energies (√s=14 TeV) the contribution from the gluon fusion background is around 20% of the contribution from quark-antiquark annihilation. These two processes do not form a severe irreducible background to the Higgs signal. At Higgs masses below 120 GeV the final state interference for the decay channel H→ZZ→4μ ± is increasingly constructive. This has no effect on the Higgs search as in this mass region the signal remains too small. One can extend the intermediate mass Higgs search via off-shell Z boson pairs at the LHC down to about 130 GeV Higgs mass. However careful study of the reducible background is needed for definite conclusions. (orig.)

EIB lends EUR 300 million for CERN's major collider

CERN Multimedia

2002-01-01

"The European Investment Bank (EIB) is lending EUR 300 million to finance the final phase of construction of the Large Hadron Collider (LHC) at CERN, the European Organization for Nuclear Research. The EIB loan will also help to finance the instrumentation to record and analyse the high-energy particle collisions at the LHC" (1 page).

Electromigration driven failures on miniature silver fuses at the Large Hadron Collider

CERN Document Server

Trikoupis, Nikolaos; Perez Fontenla, Ana Teresa

2017-01-01

Spurious faults were observed on the miniature silver fuses of electronic cards used for the cryogenics instrumentation in the LHC (Large Hadron Collider) accelerator at CERN. By applying analytical tools and techniques such as Scanning Electron Microscopy, spectrometry and Weibull reliability calculations and by the knowledge of operating temperatures and operational time of each unit, the origin of the problem has now been understood and can be attributed to electromigration. The selected fuse was operated at moderate temperature and load conditions and was considered as a “lifetime” component. However, it turned out to have a smaller than expected MTTF with failures following a Weibull distribution of $\\beta = 3.91$ and $\\eta = 2323$. The literature describes extensively the effects of electromigration, but there are only limited references referring to the impact of this phenomenon on miniature silver fuses for electronic circuits.

LHC physics: challenges for QCD

OpenAIRE

Frixione, S.

2003-01-01

I review the status of the comparisons between a few measurements at hadronic colliders and perturbative QCD predictions, which emphasize the need for improving the current computations. Such improvements will be mandatory for a satisfactory understanding of high-energy collisions at the LHC

Slice through an LHC bending magnet

CERN Multimedia

Slice through an LHC superconducting dipole (bending) magnet. The slice includes a cut through the magnet wiring (niobium titanium), the beampipe and the steel magnet yokes. Particle beams in the Large Hadron Collider (LHC) have the same energy as a high-speed train, squeezed ready for collision into a space narrower than a human hair. Huge forces are needed to control them. Dipole magnets (2 poles) are used to bend the paths of the protons around the 27 km ring. Quadrupole magnets (4 poles) focus the proton beams and squeeze them so that more particles collide when the beams’ paths cross. There are 1232 15m long dipole magnets in the LHC.

Signals of doubly-charged Higgsinos at the CERN Large Hadron Collider

International Nuclear Information System (INIS)

Demir, Durmus A.; Frank, Mariana; Turan, Ismail; Huitu, Katri; Rai, Santosh Kumar

2008-01-01

Several supersymmetric models with extended gauge structures, motivated by either grand unification or by neutrino mass generation, predict light doubly-charged Higgsinos. In this work we study productions and decays of doubly-charged Higgsinos present in left-right supersymmetric models, and show that they invariably lead to novel collider signals not found in the minimal supersymmetric model or in any of its extensions motivated by the μ problem or even in extra dimensional theories. We investigate their distinctive signatures at the Large Hadron Collider in both pair- and single-production modes, and show that they are powerful tools in determining the underlying model via the measurements at the Large Hadron Collider experiments.

Top Quark Production at Hadron Colliders

Energy Technology Data Exchange (ETDEWEB)

Phaf, Lukas Kaj [Univ. of Amsterdam (Netherlands)

2004-03-01

This thesis describes both theoretical and experimental research into top quark production. The theoretical part contains a calculation of the single-top quark production cross section at hadron colliders, at Next to Leading Order (NLO) accuracy. The experimental part describes a measurement of the top quark pair production cross section in proton-antiproton collisions, at a center of mass energy of 1.96 TeV.

The Large Hadron Collider - Expectations and Reality

International Nuclear Information System (INIS)

Litov, Leandar

2010-01-01

The Large Hadron Colider (LHC) is the biggest particle accelerator in the world designed to accelerate protons and heavy ions to extremely high energies. The four detector complexes installed around the beam crossing points, are expected to shed light on some of the more fundamental questions about our Universe ever asked--what are the fundamental constituents of the matter, what are the forces controlling their behavior and what is the structure of the space-time. In November, the LHC will be restarted and the detector complexes are expected to commence taking the first collision data. The physical motivation for the LHC experimental program and some open questions of the Standard Model of strong and electroweak interactions (SM) are discussed. Special attention is paid to observation of signatures for physics beyond the SM and the discovery potential of the LHC experiments is commented. One of the two general-purpose detector complexes (CMS, the Compact Muon Solenoid) is described briefly.

LHC Report: LHC smashes collision records

CERN Multimedia

Sarah Charley

2016-01-01

The Large Hadron Collider is now producing more than a billion proton-proton collisions per second.   The LHC is colliding protons at a faster rate than ever before: approximately 1 billion times per second. Since April 2016, the LHC has delivered more than 30 inverse femtobarns (fb-1) to both ATLAS and CMS. This means that around 2.4 quadrillion (2.4 million billion) collisions have been seen by each of the experiments this year. The inverse femtobarn is the unit of measurement for integrated luminosity, indicating the cumulative number of potential collisions. This compares with the total of 33.2 fb-1 produced between 2010 and 2015. The unprecedented performance this year is the result of both the incremental increases in collision rate and the sheer amount of time the LHC has been up and running. This comes after a slow start-up in 2015, when scientists and engineers still needed to learn how to operate the machine at a much higher energy. “With more energy, the machine is much more sen...

Design and implementation of a crystal collimation test stand at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Mirarchi, D.; Redaelli, S.; Scandale, W. [CERN, European Organization for Nuclear Research, Geneva 23 (Switzerland); Hall, G. [Imperial College, Blackett Laboratory, London (United Kingdom)

2017-06-15

Future upgrades of the CERN Large Hadron Collider (LHC) demand improved cleaning performance of its collimation system. Very efficient collimation is required during regular operations at high intensities, because even a small amount of energy deposited on superconducting magnets can cause an abrupt loss of superconducting conditions (quench). The possibility to use a crystal-based collimation system represents an option for improving both cleaning performance and impedance compared to the present system. Before relying on crystal collimation for the LHC, a demonstration under LHC conditions (energy, beam parameters, etc.) and a comparison against the present system is considered mandatory. Thus, a prototype crystal collimation system has been designed and installed in the LHC during the Long Shutdown 1 (LS1), to perform feasibility tests during the Run 2 at energies up to 6.5 TeV. The layout is suitable for operation with proton as well as heavy ion beams. In this paper, the design constraints and the solutions proposed for this test stand for feasibility demonstration of crystal collimation at the LHC are presented. The expected cleaning performance achievable with this test stand, as assessed in simulations, is presented and compared to that of the present LHC collimation system. The first experimental observation of crystal channeling in the LHC at the record beam energy of 6.5 TeV has been obtained in 2015 using the layout presented (Scandale et al., Phys Lett B 758:129, 2016). First tests to measure the cleaning performance of this test stand have been carried out in 2016 and the detailed data analysis is still on-going. (orig.)

Design and implementation of a crystal collimation test stand at the Large Hadron Collider

International Nuclear Information System (INIS)

Mirarchi, D.; Redaelli, S.; Scandale, W.; Hall, G.

2017-01-01

Future upgrades of the CERN Large Hadron Collider (LHC) demand improved cleaning performance of its collimation system. Very efficient collimation is required during regular operations at high intensities, because even a small amount of energy deposited on superconducting magnets can cause an abrupt loss of superconducting conditions (quench). The possibility to use a crystal-based collimation system represents an option for improving both cleaning performance and impedance compared to the present system. Before relying on crystal collimation for the LHC, a demonstration under LHC conditions (energy, beam parameters, etc.) and a comparison against the present system is considered mandatory. Thus, a prototype crystal collimation system has been designed and installed in the LHC during the Long Shutdown 1 (LS1), to perform feasibility tests during the Run 2 at energies up to 6.5 TeV. The layout is suitable for operation with proton as well as heavy ion beams. In this paper, the design constraints and the solutions proposed for this test stand for feasibility demonstration of crystal collimation at the LHC are presented. The expected cleaning performance achievable with this test stand, as assessed in simulations, is presented and compared to that of the present LHC collimation system. The first experimental observation of crystal channeling in the LHC at the record beam energy of 6.5 TeV has been obtained in 2015 using the layout presented (Scandale et al., Phys Lett B 758:129, 2016). First tests to measure the cleaning performance of this test stand have been carried out in 2016 and the detailed data analysis is still on-going. (orig.)

Design and implementation of a crystal collimation test stand at the Large Hadron Collider

Science.gov (United States)

Mirarchi, D.; Hall, G.; Redaelli, S.; Scandale, W.

2017-06-01

Future upgrades of the CERN Large Hadron Collider (LHC) demand improved cleaning performance of its collimation system. Very efficient collimation is required during regular operations at high intensities, because even a small amount of energy deposited on superconducting magnets can cause an abrupt loss of superconducting conditions (quench). The possibility to use a crystal-based collimation system represents an option for improving both cleaning performance and impedance compared to the present system. Before relying on crystal collimation for the LHC, a demonstration under LHC conditions (energy, beam parameters, etc.) and a comparison against the present system is considered mandatory. Thus, a prototype crystal collimation system has been designed and installed in the LHC during the Long Shutdown 1 (LS1), to perform feasibility tests during the Run 2 at energies up to 6.5 TeV. The layout is suitable for operation with proton as well as heavy ion beams. In this paper, the design constraints and the solutions proposed for this test stand for feasibility demonstration of crystal collimation at the LHC are presented. The expected cleaning performance achievable with this test stand, as assessed in simulations, is presented and compared to that of the present LHC collimation system. The first experimental observation of crystal channeling in the LHC at the record beam energy of 6.5 TeV has been obtained in 2015 using the layout presented (Scandale et al., Phys Lett B 758:129, 2016). First tests to measure the cleaning performance of this test stand have been carried out in 2016 and the detailed data analysis is still on-going.

NLO supersymmetric QCD corrections to tt-bar h0 associated production at hadron colliders

International Nuclear Information System (INIS)

Wu Peng; Ma Wengan; Hou Hongsheng; Zhang Renyou; Han Liang; Jiang Yi

2005-01-01

We calculate NLO QCD corrections to the lightest neutral Higgs boson production associated with top quark pair at hadron colliders in the minimal supersymmetric standard model (MSSM). Our calculation shows that the total QCD correction significantly reduces its dependence on the renormalization/factorization scale. The relative correction from the SUSY QCD part approaches to be a constant, if either M S or m g- bar is heavy enough. The corrections are generally moderate (in the range of few percent to 20%) and under control in most of the SUSY parameter space. The relative correction is obviously related to m g- bar , A t and μ, but not very sensitive to tanβ, M S at both the Tevatron and the LHC with our specified parameters

A silicon strip module for the ATLAS inner detector upgrade in the super LHC collider

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Sevilla, S., E-mail: Sergio.Gonzalez.Sevilla@cern.ch [DPNC, University of Geneva, CH 1211 Geneva 4 (Switzerland); Barbier, G. [DPNC, University of Geneva, CH 1211 Geneva 4 (Switzerland); Anghinolfi, F. [European Organization for Nuclear Research, CERN CH-1211, Geneva 23 (Switzerland); Cadoux, F.; Clark, A. [DPNC, University of Geneva, CH 1211 Geneva 4 (Switzerland); Dabrowski, W.; Dwuznik, M. [AGH University of Sceince and Technology, Faculty of Physics and Applied Computer Science, Krakow (Poland); Ferrere, D. [DPNC, University of Geneva, CH 1211 Geneva 4 (Switzerland); Garcia, C. [IFIC, Instituto de Fisica Corpuscular (CSIC-Universitat de Valencia), Edificio Investigacion Paterna, Apartado 22085 46071 Valencia (Spain); Ikegami, Y. [KEK, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Hara, K. [University of Tsukuba, School of Pure and Applied Sciences, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571 (Japan); Jakobs, K. [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Kaplon, J. [European Organization for Nuclear Research, CERN CH-1211, Geneva 23 (Switzerland); Koriki, T. [KEK, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Lacasta, C. [IFIC, Instituto de Fisica Corpuscular (CSIC-Universitat de Valencia), Edificio Investigacion Paterna, Apartado 22085 46071 Valencia (Spain); La Marra, D. [DPNC, University of Geneva, CH 1211 Geneva 4 (Switzerland); Marti i Garcia, S. [IFIC, Instituto de Fisica Corpuscular (CSIC-Universitat de Valencia), Edificio Investigacion Paterna, Apartado 22085 46071 Valencia (Spain); Parzefall, U. [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Pohl, M. [DPNC, University of Geneva, CH 1211 Geneva 4 (Switzerland); Terada, S. [KEK, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan)

2011-04-21

The ATLAS detector is a general purpose experiment designed to fully exploit the discovery potential of the Large Hadron Collider (LHC) at a nominal luminosity of 10{sup 34} cm{sup -2} s{sup -1}. It is expected that after several years of successful data-taking, the LHC physics program will be extended by increasing the peak luminosity by one order of magnitude. For ATLAS, an upgrade scenario will imply the complete replacement of the Inner Detector (ID), since the current tracker will not provide the required performance due to cumulated radiation damage and a dramatic increase in the detector occupancy. In this paper, a proposal of a double-sided silicon micro-strip module for the short-strip region of the future ATLAS ID is presented. The expected thermal performance based upon detailed FEA simulations is discussed. First electrical results from a prototype version of the next generation readout front-end chips are also shown.

A silicon strip module for the ATLAS inner detector upgrade in the super LHC collider

CERN Document Server

Gonzalez-Sevilla, S; Parzefall, U; Clark, A; Ikegami, Y; Hara, K; Garcia, C; Jakobs, K; Dwuznik, M; Terada, S; Barbier, G; Koriki, T; Lacasta, C; Unno, Y; Anghinolfi, F; Cadoux, F; Garcia, S M I; Ferrere, D; La Marra, D; Pohl, M; Dabrowski, W; Kaplon, J

2011-01-01

The ATLAS detector is a general purpose experiment designed to fully exploit the discovery potential of the Large Hadron Collider (LHC) at a nominal luminosity of 10(34)cm(-2)s(-1). It is expected that after several years of successful data-taking, the LHC physics program will be extended by increasing the peak luminosity by one order of magnitude. For ATLAS, an upgrade scenario will imply the complete replacement of the Inner Detector (ID), since the current tracker will not provide the required performance due to cumulated radiation damage and a dramatic increase in the detector occupancy. In this paper, a proposal of a double-sided silicon micro-strip module for the short-strip region of the future ATLAS ID is presented. The expected thermal performance based upon detailed FEA simulations is discussed. First electrical results from a prototype version of the next generation readout front-end chips are also shown. (C) 2010 Elsevier B.V. All rights reserved.

Gravitino LSP scneario at the LHC

International Nuclear Information System (INIS)

Heisig, Jan

2010-05-01

In this thesis we discuss the phenomenology of the gravitino LSP scenario at the large hadron collider (LHC) experiment. We concentrate on a long-lived stau NLSP which gives rise to a prominent signature in the LHC detector as a 'slow muon'. We discuss the production channels and compute the cross sections for direct production via the Drell-Yan process. On this basis we claim a conservative estimation of the discovery potential for this scenario at the LHC. (orig.)

Higgs physics at LHC

Indian Academy of Sciences (India)

The large hadron collider (LHC) and its detectors, ATLAS and CMS, are being built to study TeV scale physics, and to fully understand the electroweak symmetry breaking mechanism. The Monte-Carlo simulation results for the standard model and minimal super symmetric standard model Higgs boson searches and ...

Electron lenses for the large hadron collider

CERN Document Server

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

2014-01-01

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

The CERN Large Hadron Collider as a tool to study high-energy density matter.

Science.gov (United States)

Tahir, N A; Kain, V; Schmidt, R; Shutov, A; Lomonosov, I V; Gryaznov, V; Piriz, A R; Temporal, M; Hoffmann, D H H; Fortov, V E

2005-04-08

The Large Hadron Collider (LHC) at CERN will generate two extremely powerful 7 TeV proton beams. Each beam will consist of 2808 bunches with an intensity per bunch of 1.15x10(11) protons so that the total number of protons in one beam will be about 3x10(14) and the total energy will be 362 MJ. Each bunch will have a duration of 0.5 ns and two successive bunches will be separated by 25 ns, while the power distribution in the radial direction will be Gaussian with a standard deviation, sigma=0.2 mm. The total duration of the beam will be about 89 mus. Using a 2D hydrodynamic code, we have carried out numerical simulations of the thermodynamic and hydrodynamic response of a solid copper target that is irradiated with one of the LHC beams. These calculations show that only the first few hundred proton bunches will deposit a high specific energy of 400 kJ/g that will induce exotic states of high energy density in matter.

The CERN Large Hadron Collider as a tool to study high-energy density matter

CERN Document Server

Tahir, N A; Gryaznov, V; Hoffmann, Dieter H H; Kain, V; Lomonosov, I V; Piriz, A R; Schmidt, R; Shutov, A; Temporal, M

2005-01-01

The Large Hadron Collider (LHC) at CERN will generate two extremely powerful 7 TeV proton beams. Each beam will consist of 2808 bunches with an intensity per bunch of 1.15*10/sup 11/ protons so that the total number of protons in one beam will be about 3*10/sup 14/ and the total energy will be 362 MJ. Each bunch will have a duration of 0.5 ns and two successive bunches will be separated by 25 ns, while the power distribution in the radial direction will be Gaussian with a standard deviation, sigma =0.2 mm. The total duration of the beam will be about 89 mu s. Using a 2D hydrodynamic code, we have carried out numerical simulations of the thermodynamic and hydrodynamic response of a solid copper target that is irradiated with one of the LHC beams. These calculations show that only the first few hundred proton bunches will deposit a high specific energy of 400 kJ/g that will induce exotic states of high energy density in matter.

Modelling of flexibles for structural analysis of short straight section of Large Hadron Collider

International Nuclear Information System (INIS)

Abhay Kumar; Dutta, Subhajit; Dwivedi, Jishnu; Soni, H.C.

2003-01-01

Short Straight Section (SSS) of Large hadron Collider (LRCM) is a 8-meter long structure with a diameter of 1 meter and it houses a twin quadrupole. The cryogens are fed to the Sass through a jumper connection between Cryogenic Distribution Line (QRL) and SSS. The bus bars travel through interconnection bellows to adjoining magnets. CAT is studying the structural behavior of cold mass and the cryostat when subjected to various forces imposed on the SSS under various operating conditions of LHC machine including realignment required to compensate local sinking of the floor of the tunnel during the LHC machine's lifetime. CAT did calculation of reaction forces and moments on the Short Straight Section due to presence of jumper connection last year after the experimental verification of finite element model at CERN. Subsequently, a unified Fe model consisting of cold mass, cold feet, vacuum vessel, main vacuum vessel bellows (large sleeves), magnet interconnects, jumper connection, service module and precision motion jacks is being developed for studying the structural behaviour. (author)

The global electroweak fit at NNLO and prospects for the LHC and ILC

International Nuclear Information System (INIS)

Baak, M.; Hoecker, A.; Cuth, J.; Schott, M.; Haller, J.; Kogler, R.; Moenig, K.; Stelzer, J.

2014-01-01

For a long time, global fits of the electroweak sector of the standard model (SM) have been used to exploit measurements of electroweak precision observables at lepton colliders (LEP, SLC), together with measurements at hadron colliders (Tevatron, LHC) and accurate theoretical predictions at multi-loop level, to constrain free parameters of the SM, such as the Higgs and top masses. Today, all fundamental SM parameters entering these fits are experimentally determined, including information on the Higgs couplings, and the global fits are used as powerful tools to assess the validity of the theory and to constrain scenarios for new physics. Future measurements at the Large Hadron Collider (LHC) and the International Linear Collider (ILC) promise to improve the experimental precision of key observables used in the fits. This paper presents updated electroweak fit results using the latest NNLO theoretical predictions and prospects for the LHC and ILC. The impact of experimental and theoretical uncertainties is analysed in detail. We compare constraints from the electroweak fit on the Higgs couplings with direct LHC measurements, and we examine present and future prospects of these constraints using a model with modified couplings of the Higgs boson to fermions and bosons. (orig.)

LHC opening delayed, operating schedule extended

CERN Multimedia

2009-01-01

"The Large Hadron Collider (LHC) will reportedly reopen in October rather than this summer [...]. The $ 6.5 billion particle accelerator has 1'232 superconducting dipole magnets out of a total of more than 1'700 large magnets" (0.5 page)

Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider

CERN Document Server

Tahir, N A; Shutov, A; Schmidt, R; Piriz, A R

2012-01-01

The Large Hadron Collider (LHC) is designed to collide two proton beams with unprecedented particle energy of 7 TeV. Each beam comprises 2808 bunches and the separation between two neighboring bunches is 25 ns. The energy stored in each beam is 362 MJ, sufficient to melt 500 kg copper. Safety of operation is very important when working with such powerful beams. An accidental release of even a very small fraction of the beam energy can result in severe damage to the equipment. The machine protection system is essential to handle all types of possible accidental hazards; however, it is important to know about possible consequences of failures. One of the critical failure scenarios is when the entire beam is lost at a single point. In this paper we present detailed numerical simulations of the full impact of one LHC beam on a cylindrical solid carbon target. First, the energy deposition by the protons is calculated with the FLUKA code and this energy deposition is used in the BIG2 code to study the corresponding...

Tile Calorimeter Upgrade Program for the Luminosity Increasing at the LHC

CERN Document Server

Cerqueira, Augusto Santiago; The ATLAS collaboration

2015-01-01

The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC). TileCal is a sampling calorimeter with approximately 10,000 channels and is operating successfully (data quality efficiency above 99%) in ATLAS, since the start of the LHC collisions. The LHC is scheduled to undergo a major upgrade, in 2022, for the High Luminosity LHC (HL-LHC), where the luminosity will be increased by a factor of 10 above the original design value. The ATLAS upgrade program for high luminosity is split into three phases: Phase 0 occurred during 2013-2014 (Long Shutdown 1), and prepared the LHC for run 2; Phase 1, foreseen for 2019 (Long Shutdown 2), will prepare the LHC for run 3, whereafter the peak luminosity reaches 2-3 x 10^{34} cm^{2}s^{-1}; finally, Phase 2, which is foreseen for 2024 (Long Shutdown 3), will prepare the collider for the HL-LHC operation (5-7 x 10^{34} cm^{2}s^{-1}). The TileCal main activities for Phase 0 were the installation of the new low v...

Tile Calorimeter Upgrade Program for the Luminosity Increasing at the LHC

CERN Document Server

Cerqueira, Augusto Santiago; The ATLAS collaboration

2015-01-01

The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC). TileCal is a sampling calorimeter with approximately 10,000 channels and is operating successfully (data quality efficiency above 99%) in ATLAS, since the start of the LHC collisions. The LHC is scheduled to undergo a major upgrade, in 2022, for the High Luminosity LHC (HL-LHC), where the luminosity will be increased by a factor of 10 above the original design value. The ATLAS upgrade program for high luminosity is split into three phases: Phase 0 occurred during 2013-2014 (Long Shutdown 1), and prepared the LHC for run 2; Phase 1, foreseen for 2019 (Long Shutdown 2), will prepare the LHC for run 3, whereafter the peak luminosity reaches 2-3 x 10^{34} cm^{2}s^{-1}; finally, Phase 2, which is foreseen for 2023 (Long Shutdown 3), will prepare the collider for the HL-LHC operation (5-7 x 10^{34} cm^{2}s^{-1}). The TileCal main activities for Phase 0 were the installation of the new low v...

Man-made Black Holes? Can a particle collider be taken too far?

CERN Multimedia

Rupley, Sebastian

2006-01-01

"Can a particle collider be taken too far? That question is being raised about the next-generation Large Hadron Collider (LHC), shown in the photo here. The huge particle pulverizer and accelerator is located at the CERN particle physics laboratory, near Geneva, Switzerland." (1/2 page)

QCD and low-x physics at a Large Hadron electron Collider

CERN Document Server

Laycock, Paul

2012-01-01

The Large Hadron electron Collider (LHeC) is a proposed facility which will exploit the new world of energy and intensity offered by the LHC for electron-proton scattering, through the addition of a new electron accelerator. This contribution, which is derived from the draft CERN-ECFA-NuPECC Conceptual Design report (due for release in 2012), addresses the expected impact of the LHeC precision and extended kinematic range for low Bjorken-x and diffractive physics, and detailed simulation studies and prospects for high precision QCD and electroweak fits. Numerous observables which are sensitive to the expected low-x saturation of the parton densities are explored. These include the inclusive electron-proton scattering cross section and the related structure functions $F_2$ and $F_L$, as well as exclusive processes such as deeply-virtual Compton scattering and quasi-elastic heavy vector meson production and diffractive virtual photon dissociation. With a hundred times the luminosity that was achieved at HERA, s...

Prospects on electroweak physics from the LHC

International Nuclear Information System (INIS)

Vikas, Pratibha

2001-01-01

The abundant production of gauge bosons, gauge boson pairs and top quarks at the LHC will offer the opportunity for comprehensive and challenging tests of theoretical predictions in the electroweak sector. Some issues which influence these measurements followed by prospects on some possible measurements by the ATLAS and CMS experiments at the Large Hadron Collider (LHC), at CERN are discussed. (author)

A TTC to Data Acquisition interface for the ATLAS Tile Hadronic calorimeter at the LHC

CERN Document Server

Valero, Alberto; The ATLAS collaboration; Torres Pais, Jose Gabriel; Soret Medel, Jesús

2017-01-01

TileCal is the central tile hadronic calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN. It is a sampling calorimeter where scintillating tiles are embedded in steel absorber plates. The tiles are read-out using almost 10,000 photomultipliers which convert the light into an electrical signal. These signals are digitized and stored in pipelines memories in the front-end electronics. Upon the reception of a trigger signal, the PMT data is transferred to the Read-Out Drivers in the back-end electronics which process and transmits the processed data to the ATLAS Data AcQuisition (DAQ) system. The Timing, Trigger and Control (TTC) system is an optical network used to distribute the clock synchronized with the accelerator, the trigger signals and configuration commands to both the front-end and back-end electronics components. During physics operation, the TTC system is used to configure the electronics and to distribute trigger information used to synchronize the different parts of the ...

On-Line Radiation Test Facility for Industrial Equipment needed for the Large Hadron Collider at CERN

CERN Document Server

Rausch, R

1999-01-01

The future Large Hadron Collider to be built at CERN will use superconducting magnets cooled down to 1.2 K. To preserve the superconductivity, the energy deposition dose levels in equipment located outside the cryostat, in the LHC tunnel, are calculated to be of the order of 1 to 10 Gy per year. At such dose levels, no major radiation-damage problems are to be expected, and the possibility of installing Commercial Of The Shelf (COTS) electronic equipment in the LHC tunnel along the accelerator is considered. To this purpose, industrial electronic equipment and circuits have to be qualified and tested against radiation to insure their long term stability and reliability. An on-line radiation test facility has been setup at the CERN Super Proton Synchrotron (SPS) and a program of on-line tests for electronic equipment is ongoing. Equipment tested includes Industrial Programmable Logic Controllers (PLCs) from several manufacturers, standard VME modules, Fieldbuses like Profibus, WorldFIP and CAN, various electro...

CKM angles measurements and New Physics at Lhc b

International Nuclear Information System (INIS)

Musy, M.

2008-01-01

In this paper a review is given of the main characteristics of the future measurements of the unitary triangle by the Lhc b experiment at the Large Hadron Collider (Lhc), and the expected achievable precision. The Lhc b experiment will be able to exploit a wide range of physics decays involving the B mesons, allowing for the possibility to have early indications of New Physics.

Rice Physicist to direct $40M LHC Program

CERN Multimedia

2006-01-01

"Rice Universty announced that physicist B. Paul Padley has been chosen to lead the scientific operations for one of the particle detector systems at the European Organization for Nuclear Research's Large Hadron Collider (LHC)."

Lead ions and Coulomb’s Law at the LHC (CERN)

Science.gov (United States)

Cid-Vidal, Xabier; Cid, Ramon

2018-03-01

Although for most of the time the Large Hadron Collider (LHC) at CERN collides protons, for around one month every year lead ions are collided, to expand the diversity of the LHC research programme. Furthermore, in an effort not originally foreseen, proton-lead collisions are also taking place, with results of high interest to the physics community. All the large experiments of the LHC have now joined the heavy-ion programme, including the LHCb experiment, which was not at first expected to be part of it. The aim of this article is to introduce a few simple physical calculations relating to some electrical phenomena that occur when lead-ion bunches are running in the LHC, using Coulomb’s Law, to be taken to the secondary school classroom to help students understand some important physical concepts.

Updates on the optics of the future hadron-hadron collider FCC-hh

CERN Document Server

AUTHOR|(CDS)2093721; Boutin, David Jean Henri; Dalena, Barbara; Holzer, Bernhard; Langner, Andy Sven; Schulte, Daniel

2017-01-01

The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the three options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. The layout of FCC-hh has been optimized to a more compact design following recommendations from civil engineering aspects. The updates on the first order and second order optics of the ring will be shown for collisions at the required centre-of-mass energy of 100 TeV. Special emphasis is put on the dispersion suppressors and general beam cleaning sections as well as first considerations of injection and extraction sections.

Introduction to beauty-hadron physics

International Nuclear Information System (INIS)

Fridman, A.

1995-03-01

These lectures discuss methods for analyzing the decay of beauty hadrons (B mesons and beauty baryons) produced in pp interactions. At the c.m. energies around 14 TeV planned for the Large Hadron Collider (LHC) at CERN, the B meson production rate is expected to be ca 105 larger than in an e+e- B factory. The pp collider could then offer, in principle, important advantages. However, the detection of beauty hadrons produced in a pp collider will be a task of great complexity. In particular, the triggering difficulties of events in a large background will be one of the major problems. Therefore, it would be useful to discuss the various aspects that can be investigated in beauty physics arising from pp interactions. It is first described the general features of the formalisms of B mixing and search for CP violation in the meson decays. Then the specific problems appearing for beauty hadrons produced in pN interactions are considered. Some comparison between investigations which could be carried out with B factories and pp colliders are also mentioned, although this is not the main concern of these lectures. Finally it is also presented some elements of beauty baryon decays which can only be studied efficiently by means of pN interaction

Introduction to beauty-hadron physics

Energy Technology Data Exchange (ETDEWEB)

Fridman, A. [Istituto Nazionale di Fisica Nucleare, Trieste (Italy)

1995-03-01

These lectures discuss methods for analyzing the decay of beauty hadrons (B mesons and beauty baryons) produced in pp interactions. At the c.m. energies around 14 TeV planned for the Large Hadron Collider (LHC) at CERN, the B meson production rate is expected to be ca 105 larger than in an e+e- B factory. The pp collider could then offer, in principle, important advantages. However, the detection of beauty hadrons produced in a pp collider will be a task of great complexity. In particular, the triggering difficulties of events in a large background will be one of the major problems. Therefore, it would be useful to discuss the various aspects that can be investigated in beauty physics arising from pp interactions. It is first described the general features of the formalisms of B mixing and search for CP violation in the meson decays. Then the specific problems appearing for beauty hadrons produced in pN interactions are considered. Some comparison between investigations which could be carried out with B factories and pp colliders are also mentioned, although this is not the main concern of these lectures. Finally it is also presented some elements of beauty baryon decays which can only be studied efficiently by means of pN interaction.

Gravitino LSP scneario at the LHC

Energy Technology Data Exchange (ETDEWEB)

Heisig, Jan

2010-06-15

In this thesis we discuss the phenomenology of the gravitino LSP scenario at the large hadron collider (LHC) experiment. We concentrate on a long-lived stau NLSP which gives rise to a prominent signature in the LHC detector as a 'slow muon'. We discuss the production channels and compute the cross sections for direct production via the Drell-Yan process. On this basis we claim a conservative estimation of the discovery potential for this scenario at the LHC. (orig.)

Magnet failure could delay the LHC

CERN Multimedia