A new model for two-body high energy scattering is presented as part of an investigation into the phenomenological consequences of the non-planar structure of Reggeon-particle scattering. The model is a modification of the weak cut reggeized Absorption model for Pion-Nucleon scattering and is developed in form of a correlation modified quasi eikonal where the Reggeon and an arbitrary number of Pomerons are allowed to change the projection of the nucleon spin. A correlation parameter - the "Gribov c" - which has its origin in Gribov's theory, provides an indication about the failure of the traditional weak cut reggeized absorption model and restores its most profound shortcoming - the prediction of an incorrect phase behaviour of the helicity isovector nonflip amplitude in the reaction while retaining the model's attractive simplicity. The vertices of the Reggeon-calculus depend in general on the angle between the momenta of the exchanged reggepoles. By parameterizing this dependence we take into account the effective contribution of inelastic intermediate states in the unitarity expansion of the Regge-particle scattering amplitude. We obtain a reasonable phase energy description of the isovector amplitude. We demonstrate in detail the mechanism by which the correct phase behaviour is restored. The spin-structure of the amplitudes is investigat ed and observables of N scattering between 6 and 200 GeV/c within a range of momentum transfer of are being produced.

The photoproduction of the p and the w was studied using data taken by the NA1 experiment at the CERN SPS. The beam was that of a tagged photon with energy between 70-225 GeV incident on an active target, which consisted of a monolithic germanium block and strips of silicon detector. The decay products were detected by the forward FRAMM spectrometer. The p and the w events were identified by their decays into and channels respectively. Using clean samples of events and taking into account their respective branching ratios and simulated geometrical acceptances the ratio was measured to be 9.64 +/- 0.54. The interaction-point distribution of a trimmed sample of p events resulted in the ratio of the interaction rates in the germanium and the silicon parts of the target, leading to the value of a, which describes the A-dependence of the nuclear cross-section by [equation] where A is the nuclear mass number. The measured [alpha] values for the overall and the coherent event samples, respectively, are [alpha] = 1.45 +- 00.5 and [alpha]Coh = 1.44+-0.06.

A preliminary measurement is presented of the lifetime of the ground state neutral charm meson, the D0. This study utilised data taken by the NA1 experiment running on the CERN SPS accelerator. A tagged photon beam was used with energies between 70 and 175Gev and the FRAMM spectrometer provided final state particle identification. The D meson production and decay points were measured with an electronically read out monolithic germanium target followed by silicon strip detectors. Charm events were identified by the reconstruction of D0 meson invariant masses where the D0 originated from a D* decay and decayed to final states containing charged kaons. A sample of 90 D0/D0 decay events was found.

An analysis of data collected In the NA1 high energy photoproduction experiment at the CERN SPS is presented. The theoretical status of charmed particle decay is reviewed. The NA1 experimental apparatus is discussed. Experiment NA1 used an active semiconductor target exposed to a 70-225 GeV tagged photon beam and the forward spectrometer FRAMM to collect data on the decay of particles carrying the charm quantum number. FRAMM was equipped with three lever arms for charged particle momentum analysis, electromagnetic calorimeters for neutral particle reconstruction and Cerenkov detectors for charged particle identification. The active target measured the charged particle multiplicity development along the beam axis to determine the decay length of particles. The proper time resolution of the target was -0.2x10^-13s. A sample of sixty-three Ac charmed baryons are isolated in the decay channel via an inclusive analysis. Twenty-four of these Acs havedecay lengths resolved in the NA1 active target which can be matched to the information in the forward spectrometer FRAMM. A study of the sixty-three reconstructed in FRAMM indicates that a large proportion decayed via the channel, a decay which is believed to proceed exclusively through W exchange.

This work investigated the design of classical and optimal control strategies to actively control the flexible modes of a high speed railway vehicle body. It explored the novel idea of adding a third actuator at the centre of the vehicle body to suppress the flexible body modes (i.e. first symmetrical and first asymmetrical) in addition to the actuators located across the front and rear secondary suspensions. The aim is to minimise the level of vibration and improve the ride quality (comfort). Both the two and three actuators are considered in the classical and optimal control strategies investigated.

No description available.

A variety of modified minerals have been screened to determine their effectiveness as agents for the catalytic transformation of the thermally generated off gases arising from the pyrolysis of the polyolefinic plastic High Density Polyethylene (HDPE). This polymer has been shown to degrade through a series of known mechanisms to yield a hydrocarbon product mixture consisting of an homologous series of saturated and unsaturated hydrocarbons which include alk-1-enes, n-alkanes, alk-x-enes and a-w-dienes. Modification treatments have been wide ranging having included activation of the parent mineral by means of pillaring, ion exchange and acid activation. The activated products have been characterised by XRD, XRF, TGA and vibrational spectroscopy. Moreover, evolved gas analysis has been employed to perform catalytic screening runs on these modified minerals. In particular, attention has been paid to the activity of these materials in respect of the formation of potentially fuel applicable hydrocarbons, namely those exhibiting high octane ratings, including aromatics and branched aliphatics from the feedstock species present in the HDPE pyrolysate gas mixture. Pillared clays (PILC's) have proven ineffective in this role as a consequence of their poor reproducibility and lack of selectivity towards the formation of single ring aromatics. Likewise, ion exchange has been found to influence strongly the catalytic behaviour of previously acid activated clays, with autotransformed samples offering dehydrocyclisation (DHC) activity at levels significantly greater than seen with some ion exchanged samples, particularly protons. Acid activated metakaolinites have demonstrated poor selectivity in terms of aromatic formation, although total DHC activity is good. Metakaolin also gave rise to appreciable activity in respect of the formation of the single ring aromatics selected for monitoring in this work. Isomerisation activity was prevalent over these materials, but coking levels were high. Acid activated smectites represent the most suitable candidates to fulfil the role of single step fuel generation from the transformation of the gas stream resulting from HDPE pyrolysis. It has been found that careful control over the chemical and physical properties of acid activated clays can be achieved through consideration of the severity of the activation parameters chosen to induce modification. In addition, the nature of the activated product is strongly dependant on the nature of the base clay. In particular, acid activated beidellites have been shown to exhibit high levels of surface acidity as determined through the thermal desorption of cyclohexylamine. These materials consequently give rise to respectable activity and selectivity in terms of the formation of highly octane rated methyl substituted single ring aromatics, principally trimethylbenzene. In contrast, acid activated montmorillonites have been seen to offer lower levels of total surface acidity and have been shown to be active in promoting skeletal isomerisation reactions to yield branched aliphatics, again, highly octane rated. This activity variation has been attributed to the formation of highly Bronsted acidic silanol containing Surface Localised Acid Pools (SLAP's) on the exposed surfaces of the former as a consequence of the isomorphous substitution patterns observed in the tetrahedral sheets of beidellites.

<p> Silicon tracking detectors are frequently used in particle collider experiments, as they can provide excellent spatial precision with little material in order to cause minimal track disruption. Due to a progressive increase in collider luminosities, a common trend in these experiments is the need for higher levels of radiation damage resistance. One proposed class of designs for pixel trackers in high luminosity colliders is the Silicon 3D trench detector. The same design can be scaled up for photon science applications. </p><p> The work discussed in this dissertation was performed as part of a collaboration between BNL, NYU, CNM and SUNY Stony Brook. The central aim of the work presented here was to evaluate the manufactured 3D trench detector prototypes and study their behavior in detail by performing a series of experimental measurements and TCAD simulations. </p><p> An experiment to measure the detector response to an Americium radioactive source was designed and used to study the noise level and charge collection efficiency of detector prototypes. An experimental system which measured the detector response to an infrared laser with computer controlled precision positioning was developed. This system was used to obtain laser pulse response maps of detectors, which in turn were utilized to investigate the dependence of charge collection efficiency of detectors on position, collection time and bias voltage. The same mapping technique was also used to study the change in irradiated detector response. </p><p> Detector response was simulated using the Silvaco TCAD Suite. These simulations were used to study depletion in large photon detectors and charge collection in response to laser hits. Approximate simulations of radiation damage were also performed to investigate the behavior of irradiated detectors. Leakage current and capacitance simulations before and after irradiation were also performed and compared to the experimental measurements. While significant variations in detector response between different prototypes were observed during the experiments, simulation results are still capable of explaining the general properties of the detectors. The combination of the simulation and the experimental results provides an understanding of the signal generation process in these detectors. </p><p> One observed problem is the large bias currents due to manufacturing surface defects. A double-sided version of the trench detector is proposed to mitigate this problem. Electric fields, depletion region shape and formation, bias voltage and transient current response of these detectors are simulated and compared with those of the standard trench detectors. Computer simulations show that the double-sided detectors also have some performance advantages over the original designs including larger more uniform spatial charge collection efficiency and higher radiation damage resistance. These simulation results and the general insensitivity of the proposed detectors to surface defects make the double-sided detectors worthy of further study.</p><p>

<p> Neutrino oscillation is a phenomenon in which neutrinos produced from charged current weak interactions can change flavor as they propagate. The mixing between the three flavor eigenstates and mass eigenstates can be measured through neutrino oscillations as the oscillation probabilities depend on the mixing angles and neutrino mass squared differences. </p><p> T2K is a long baseline neutrino experiment, in which a nearly pure muon neutrino or muon antineutrino beam is produced at J-PARC on the east coast of Japan and travels 295 km through the Earth&rsquo;s crust towards the far detector, Super-Kamiokande (Super-K), a 50 kiloton water Cherenkov detector, in the west of Japan. The neutrino fluxes in the absence of oscillation are measured by the near detectors 280 meters away from the target, and again with oscillation effects at Super-K. Aside from the beam neutrino from J-PARC, Super-K also measures neutrino oscillations independently through the neutrinos produced in the Earth's atmosphere. </p><p> This thesis presents the first analysis in which both the T2K beam neutrino data and the sub-GeV atmospheric neutrino data at Super-K are used in a unified framework to measure neutrino oscillation parameters. The beam neutrino samples are selected for optimal sensitivity to sin²&thetas;₂₃ and &delta;_CP. A Bayesian analysis using a Markov Chain Monte Carlo method is performed. Using T2K Runs 1&ndash;8 data which amounts to 14.7 &times; 10₂₀ protons on target (POT) in neutrino-mode and 7.6 &times; 10₂₀ POT in antineutrino-mode, and 2520 days of Super-K data, the oscillation parameters are measured to be sin²&thetas;₂₃ = 0.528^+0.032_&ndash;0.028, |&Delta;<i> m</i>²₃₂| = 2.46^+0.084_&ndash;0.060(10^&ndash;3eV²), sin²&thetas;₁₃ = 0.0270^+0.0065_{&ndash;0.0047}; and the 90% credible interval of &delta;_CP is [&ndash;&pi;, &ndash;0.18]&amp;[2.33, &pi;]. When the data is also combined with the constraint on sin² 2&thetas;₁₃ = 0.0857 &plusmn; 0.046 from reactor neutrino experiments, the oscillation parameters are measured to be sin²&thetas;₂₃ = 0.543^+0.026_&ndash;0.023, |&Delta;<i>m</i>² 32| = 2.49^+0.042_&ndash;0.090(10^&ndash;3eV²), sin²&thetas;₁₃ = 0.0223^+0.0012_{&ndash;0.0013}; the 90% credible interval of &delta;_CP is [&ndash;&pi;, &ndash;0.628], and the CP-conserving value &delta;_CP = 0 is excluded at 2&sigma;.</p><p>

<p> A search for Higgs boson pair production in the four b-jet final state is carried out with up to 36.1/fb of LHC proton--proton collision data collected at &radic;<i>s</i> = 13 TeV with the ATLAS detector in 2015 and 2016. Three benchmark signals are studied: a spin-2 graviton decaying into a Higgs boson pair, a scalar resonance decaying into a Higgs boson pair, and Standard Model non-resonant Higgs boson pair production. This thesis presents a search in events with four individually resolved b-tagged jets. Higgs bosons produced with large momenta are reconstructed as single large radius jets with substructure. The analysis of this topology is presented in CERN-THESIS-2018-118. The two analyses are statistically combined and upper limits on the production cross section of Higgs boson pairs times branching ratio to four b-quarks are set in each model. The combined result searches for resonance masses in the range 260&ndash;3000 GeV. No significant excess is observed; the largest deviation of data over prediction is found at a mass of 280 GeV, corresponding to 2.3 standard deviations globally. The observed 95% confidence level upper limit on the non-resonant production is 13 times the Standard Model prediction.</p><p>