high energy proton-proton colliders

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Exclusive vector mesons at high energies: from photon-proton to proton-proton and nucleus-nucleus collisions

Exclusive vector mesons at high energies: from photon-proton to proton-proton and nucleus-nucleus collisions

Abstract. Photoproduction of vector mesons has been studied since the 1960’s and was instrumental in establishing the hadronic structure of the photon and the concept of vector- meson dominance. More recently our knowledge on vector meson photoproduction has been furthered by experiments at the HERA accelerator. Total cross sections ans well as a number of kinematical distributions have been measured from light to heavy vector mesons. These experiments have been a testbed of ideas on the production mechanism, the QCD Pomeron exchange. In particular in varying the mass of the vector meson we can study the Pomeron exchange from the soft to the perturbatively hard regimes. The production mechanism also contains information on the quark-antiquark wave function of the produced meson. High energy protons or ions are the source of a flux of Weizs¨acker- Williams photons, which can be utilized to study the photoproduction of vector mesons also at the Tevatron and LHC colliders. We discuss how information on the small-x gluon distribution in protons in nuclei can be obtained. Besides this intrinsic interest in vector meson production, a precise knowledge thereof is also necessary for odderon searches. In this regard, we discuss also transverse momentum distributions including absorption effects.
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AWAKE : a proton-driven plasma wakefield acceleration experiment at CERN

AWAKE : a proton-driven plasma wakefield acceleration experiment at CERN

Lepton linear colliders, operating at the TeV energy scale, represent one option to search for new physics and complement the results obtained from the LHC at CERN. The present RF cavities or microwave technolo- gies allow to achieve a maximum accelerating gradient of ∼100 MV/m. The future linear colliders should then be several tens of kilometres long to achieve the TeV range. It was predicted that a plasma can sustain three orders of magnitude higher gradients than the RF cavi- ties [1, 2] so that studies on possible “compact” plasma- based accelerators became of great interest. A plasma acts as an energy transformer which transfers the energy from a drive to a witness bunch. The maximum energy gain per particle of the accelerated beam, in a single plasma stage, is limited by the energy of the driver. Cur- rent proton synchrotrons are capable of producing high energy beams, reaching up to multi TeV. Simulations showed that an LHC-type proton bunch (1 TeV, 10 11
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AWAKE:a proton driven plasma wakefield acceleration experiment at CERN

AWAKE:a proton driven plasma wakefield acceleration experiment at CERN

Lepton linear colliders, operating at the TeV energy scale, represent one option to search for new physics and complement the results obtained from the LHC at CERN. The present RF cavities or microwave technolo- gies allow to achieve a maximum accelerating gradient of ∼100 MV/m. The future linear colliders should then be several tens of kilometres long to achieve the TeV range. It was predicted that a plasma can sustain three orders of magnitude higher gradients than the RF cavi- ties [1, 2] so that studies on possible “compact” plasma- based accelerators became of great interest. A plasma acts as an energy transformer which transfers the energy from a drive to a witness bunch. The maximum energy gain per particle of the accelerated beam, in a single plasma stage, is limited by the energy of the driver. Cur- rent proton synchrotrons are capable of producing high energy beams, reaching up to multi TeV. Simulations showed that an LHC-type proton bunch (1 TeV, 10 11
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Particle dynamics in a non flaring solar active region model

Particle dynamics in a non flaring solar active region model

To estimate the number of trapped orbits, we count any or- bit which contains two or more mirror points (locations where the parallel velocity reverses sign) as being “trapped”. We es- timate that, out of the 2000 orbits initialised in the manner de- scribed earlier, 1061 electron and 228 proton orbits are mirrored twice or more. To present a fair comparison (with protons taking longer to reach two or more mirror points), we extended the sim- ulation time of proton orbits from 10 s to 1000 s. While this is much longer than the 90 s cadence of the MHD simulations, our objective here is simply to assess under what conditions similar number of protons and electrons may be trapped. With an ex- tended time-range, the number of trapped proton orbits rises to 840. Thus, this trapping occurs for a significant fraction of the orbits considered in these surveys, but the true number of parti- cles per species trapped by this mechanism is related to the time over which the MHD fields evolve, how these fields evolve, and the species mass and charge. Individual particle orbit examples, including trapped orbits, are studied in greater detail in Sect. 4.
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A Measurement of Jet Shapes in Proton Proton Collisions at 7 0 TeV Center of Mass Energy with the ATLAS Detector at the Large Hadron Collider

A Measurement of Jet Shapes in Proton Proton Collisions at 7 0 TeV Center of Mass Energy with the ATLAS Detector at the Large Hadron Collider

ATLAS has implemented a three-tier trigger system to handle the high-rate environment. At each level, physics objects are reconstructed with improved granularity and precision and over a larger fraction of the detector, culminating in complete event reconstruction in the final trigger stage. The level-one (L1) trigger is a configurable, pure-hardware trigger that is designed to make a decision on each event in under 2.5 µs and provide output at a rate up to 75 kHz. No inner detector information is used at this stage, and only very simple calorimetric and muon reconstruction information is available. The level-two (L2) triggers make a decision in under 40 ms and provide output at rates up to 3.5 kHz. The L2 triggers run a simplified version of the event reconstruction in the regions of interest defined by the calorimeter and muon systems. Improved selection criteria, such as distinguishing electrons from photons by track matching, and improved calibrations are applied. Some limited identification of b-jets is done, and the missing transverse energy measurement is refined, for example to include muons. In the level-three trigger, called the “event filter” (EF), the complete offline event reconstruction makes a decision in under 4 s and provides output at 200-400 Hz. The L2 and EF are both software triggers, unlike the L1 trigger, and they are together referred to as the “high-level trigger” (HLT). In 2009 and 2010, rates between 100 and 200 Hz were not uncommon.
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Experiments on extreme states of matter towards HIF at FAIR

Experiments on extreme states of matter towards HIF at FAIR

An intense focused heavy ion beam heats large-volume targets uniformly and quasi-isochorically, thereby generating states of high pressure and high entropy. The heated material can then expand isentropically and depending on the deposited energy, will reach different physical states of HED matter. These include an expanded hot liquid, the region near the critical point, two-phase liquid-gas region, strongly coupled (non-ideal) plasmas and warm dense matter (WDM) regions. Such ion-beam generated samples can be used to study the Equation of State (EOS) properties of different phases of HED matter. This scheme is named HIHEX (Heavy Ion Heating and Expansion) [4, 8] and is an important part of the experimental program at FAIR. It is to be noted that some of the above HED states are either very difficult to achieve or are inaccessible using the traditional methods by shock in the limited region of the principal and porous Hugoniots (shock adiabats).
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Effects of temperature and extracellular pH on metabolites: kinetics of
anaerobic metabolism in resting muscle by 31P  and
1H NMR spectroscopy

Effects of temperature and extracellular pH on metabolites: kinetics of anaerobic metabolism in resting muscle by 31P and 1H NMR spectroscopy

gradient and (2) is intracellularly produced by metabolism. In all tissues, the maintenance of ion gradients across cell membranes constitutes an important fraction of the cellular energy consumption. Energy supply, under anaerobic conditions, is provided by both PCr hydrolysis and anaerobic glycolysis, the latter resulting in lactate acidosis. In isolated muscle, the external acidosis has been shown to decrease, and alkalosis to increase, the net lactic acid production (Hood et al., 1988). These findings have been mainly ascribed to the pHi dependence of the phosphofructokinase enzyme (Trivedi and Danforth, 1966). Actually, the data in Fig.·2F for 5–10·h after the onset of the experiment show that, at T=25°C, a decrease in the extracellular pH induces a depression of anaerobic glycolysis. However, in our case, pHi can be excluded as the regulatory signal causing the metabolic depression. In fact, at all the examined pHe in the phase corresponding to the induction of the lactate metabolic inhibition (i.e. <5·h; see Fig.·2F), pHi values are similar.
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Production of quarkonium pairs in high-energy proton-proton collisions

Production of quarkonium pairs in high-energy proton-proton collisions

These processes serve as a tool to investigate the dynamics of particle production in high- energy proton-proton collisions. In particular it has been suggested that J/ψ-pair production can be used to study double-parton scattering (DPS) [6]. Indeed, as has been shown in [7], the DPS contribution is especially large in the charm sector.

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Current status of the LHCf experiment and future plan

Current status of the LHCf experiment and future plan

No model is able to describe completely the experimental data. The Data used in this analysis was obtained on 15 May 2010 during proton-proton collisions at √ s = 7 TeV with zero degree beam crossing angle (LHC Fill 1104). The total luminosity of the three crossing bunches in this fill was L = (6.3 − 6.5) × 10 28 cm − 2 s − 1 . The ranges used for the small calorimeters and the large calorimeters are [ > 10.94, = 360.0] and [8.99 > > 8.81, = 20.0], respectively. Only single hit events were selected in this analysis. The result was summarized in [5].

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Studying η-Meson Decays with WASA-at-COSY

Studying η-Meson Decays with WASA-at-COSY

Both values are in agreement with the current KLOE results. However, Fig. 4 already indicates a need for more statistics in order to decrease the statistical uncertainties. Therefore, this measurement will be redone with the proton-proton data set. A first estimation shows that about ∼ 1 k η → π + π − e + e − events are expected for the full pp → ppη data set, which is comparable with the statistics from the KLOE experiment.

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Control of Microdomain Orientation in Block Copolymer Thin Films by Electric Field for Proton Exchange Membrane

Control of Microdomain Orientation in Block Copolymer Thin Films by Electric Field for Proton Exchange Membrane

In order to improve the overall performances and efficiencies of fuel cells, it is critical to incorporate high performance proton conducting membranes (PCMs), especially in two kinds of popular fuel cells such as proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) [2] [3]. To date, the PCM based on sulfonated fluorocarbon polymer, for example, Nafion ® is the most widely used one [4]. Even if Nafion has high proton conductivity and good thermal stability, its methanol permeability is too high to use in practical ap- plications [4]. Therefore, several attempts have been made in order to develop Nafion ® membranes exhibiting reduced methanol permeability while maintaining proton conductivity [4]-[8].
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Steepness of the Lateral Distribution Function of Secondary Hadrons in Extensive Air Showers

Steepness of the Lateral Distribution Function of Secondary Hadrons in Extensive Air Showers

The influence of high and low energy hadronic interaction models on hadrons lateral distribution of cosmic ray air showers for primary energies 10 17 -10 19 eV is explored. By using CORSIKA simulation code hadrons lateral distribution and also steepness of the hadron lateral distribution function is studied. We have shown η (the steepness of the lateral distribution) is increases with increasing primary energy and is decreases with increasing primary mass. We have investigated hadrons lateral distribution and their dependence on the primary energy and mass of cosmic ray induced air showers. η can be directly related to the shower maximum (X max ) and also it can
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Search for Stop Pair Production at the LHC using the CMS Detector

Search for Stop Pair Production at the LHC using the CMS Detector

Backgrounds are estimated from MC simulations, nor- malized to the number of events in data in the trans- verse mass peak region, which is dominated by SM back- grounds. This minimizes systematic uncertainties associ- ated with the knowledge of the tt production cross sec- tion, the integrated luminosity, the lepton e ffi ciency, and jet energy scale. The simulation is validated in control re- gions (CRs) intended to enrich the data sample in specific background sources while maintaining kinematical prop- erties that are similar to those in the SRs. Three CRs are used: a sample dominated by t¯t → ` + ` − events obtained
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Mitochondrial proton leak compensates for reduced oxidative power during frequent hypothermic events in a protoendothermic mammal, Echinops telfairi

Mitochondrial proton leak compensates for reduced oxidative power during frequent hypothermic events in a protoendothermic mammal, Echinops telfairi

the cellular basis supporting this unique pattern is not well-understood. The bioenergetics of liver mitochondria are well-established nominators of (basal) metabolic rates (Porter and Brand, 1995; Polymeropoulos et al., 2012) and actively adjust in response to hypothermic states in some rodent species (Staples and Brown, 2008; Kutschke et al., 2013). Thus, investigating temperature-dependent bioenergetics in the frequently heterothermic tenrec may yield relevant insights into concepts and mechanisms that occurred during early evolution of eutherian metabolism. Therefore, we investigated the flexibility of mitochondrial function in response to acute and chronic temperature changes in isolated liver mitochondria of tenrecs. In contrast to some ectothermic vertebrates such as fish and amphibians, where mitochondrial state 4 respiration and proton leak rate is suppressed in chronic cold (Jastroch et al., 2007; Trzcionka et al., 2008), acclimation temperature had no such impact on liver mitochondrial proton leak in the tenrec (Figure 3). This finding may indicate that there are no functional, long-term changes accompanied by cold acclimatization. In our experiments, we sacrificed the animals at normothermic temperatures for experimental consistency. Under these experimental conditions, putative, rapid molecular changes in response to hypothermic or hypometabolic states in torpor may be missed.
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Path to AWAKE:evolution of the concept

Path to AWAKE:evolution of the concept

Two beams of di ff erent energies were analyzed as possible candidates for the first experiment on proton driven plasma wakefield acceleration: a 24 GeV beam in the Proton Syn- chrotron (PS) and 450 GeV beam in the SPS. At low ener- gies (24 GeV), the excited fields turn out to be much lower be- cause of the quick emittance-driven blowup of the beam radius [47, 50]. Therefore the SPS proton beam was chosen. The ten meter long plasma envisaged for the first experiment is too short to produce a reliably measurable energy change of the proton beam [51, 52] (Fig. 4). Therefore, injection of exter- nally produced electrons becomes a must for probing the ex- cited wakefields. With the addition of the electron beam, the broad outlines of the experiment were settled, and the project was proposed for realization at CERN in the Letter of Intent [53], which was submitted to the SPS Committee in May 2011. The experiment was recommended for further review, including preparation of a Design Report.
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A novel treatment of the proton-proton Coulomb force in proton-deuteron Faddeev calculations

A novel treatment of the proton-proton Coulomb force in proton-deuteron Faddeev calculations

Abstract. We present resently introduced novel approach to include the proton-proton (pp) Coulomb force into the momentum space three-nucleon (3N) Faddeev calculations. It is based on a standard formulation for short range forces and relies on a screening of the long-range Coulomb interaction. In order to avoid all uncertainties connected with an application of the partial wave expansion, unsuitable when working with long-range forces, we apply directly the 3-dimensional pp screened Coulomb t-matrix. That main new ingredient, the 3-dimensional screened pp Coulomb t-matrix, is obtained by a numerical solution of the 3-dimensional Lippmann-Schwinger (LS) equation. Using a simple dynamical model for the nuclear part of the interaction we demonstrate the feasi- bility of that approach. The physical elastic pd scattering amplitude has a well defined screening limit and does not require renormalisation. Well converged elastic pd cross sections are obtained at finite screening radii. Also the proton-deuteron (pd) breakup observables can be determined from the resulting on-shell 3N amplitudes in- creasing the screening radius. However, contrary to the pd elastic scattering, the screening limit exists only after renormalisation of the pp t-matrices.
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Heavy-ion reaction studies of nuclei far from stability

Heavy-ion reaction studies of nuclei far from stability

The recently completed recoil spectrometer TOFI [Wol87] successfully employs the high energy proton beam available from the LAMPP accelerator at Los Alamos to provide a high production r[r]

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The Charge Structures of Aether and Substance

The Charge Structures of Aether and Substance

Into the inner nuclear energy makes the contribution the “weak” oscillations influencing on stability of a nuclide, causing in the unstable positions breaking the bonds that fasten nuclear structure. It must be note that nuclide stability is a relatively rare phenomenon. Today we know 300 stable nuclides and more than 3000 unstable radionuclides with charge structure that does not provide a perfect balance of the interaction forces. In this case the dynamics of the substructures rotation cycles in radionuclides with a certain period leads to critical states when the structure stability depends from weak oscillations. This hypothesis qualita- tively explains the factors of randomness and cyclicity that characterize the processes of radionuclide decay. Also note that the existing theories of strong and weak interactions do not provide a qualitative explanation of internal nuc- lear processes that lead to decay of the unstable charge structures and do not of- fer a method estimation of the half decay period.
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Renormalization of Proton-Proton Scattering and Proton-Proton Fusion with Chiral Two Pion Exchange: Regulator Independent Results.

Renormalization of Proton-Proton Scattering and Proton-Proton Fusion with Chiral Two Pion Exchange: Regulator Independent Results.

Proton-proton fusion matrix elements can be evaluated in a straightforward manner, yielding in the impulse ap- proximation values of the overlap integral slightly smaller than those obtained with phenomenological wave functions. This is necessary feature due to the bigger contribution of finite range axial two body currents for the renormalized computations. Unfortunately the final value of the overlap integral is still unavailable, as it would require to take into account the contact range contributions to the two body current, which so far can only be constrained by tritium beta decay. Consequently, a renormalized computation of the three nucleon bound state is a prerequisite for a com- plete chiral computation of proton-proton fusion.
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Laser acceleration of protons using multi-ion plasma gaseous targets

Laser acceleration of protons using multi-ion plasma gaseous targets

however, is relativistically underdense to the laser wave, since n e,max ∼ 2 n cr < 10 n cr , as shown in fi gure 2(r). The laser starts to penetrate the electron cloud, and the thermal expansion of the electrons and carbon ions becomes more and more significant. As a result, all carbon ions that accelerated due to the acceleration mechanisms of shock, RPA, and TNSA, as mentioned previously, start to merge altogether (figures 2(m) and 4(c)). Meanwhile, because of a greater charge-to-mass ratio, some of the protons are further accelerated, leaving some of them trapped in the carbon ion layer and a small amount of them being accelerated in a backward direction. The front end, as well as the rear end, of the proton layer start to be accelerated by the SCR in both directions at this time.
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