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Emittance Control In Laser Wakefield Accelerator
Get PDFIn this paper we summarize our recent effort and results in theoretical study of the emittance issues of multistaged Laser Wakefield Accelerator (LWFA) in TeV energy range, In such an energy regime the luminosity and therefore the emittance requirements become very stringent and tantamount to the success or failure of such an accelerator. The system of such a machine is very sensitive to jitters due to misalignment between the beam and the wakefield. In particular, the effect of jitters in the presence of a strong focusing wakefield and initial longitudinal phase space spread of the beam leads to severe transverse emittance degradation of the beam. To improve the emittance we introduce several methods: a mitigated wakefield focusing by working with a plasma channel, an approximately synchronous acceleration in a superunit setup, the >horn> model based on exactly synchronous acceleration achieved through plasma density variation and lastly an algorithm based on minimization of the final beam emittance to actively control the stage displacement of such an accelerator.Physic
Critical Point Fluctuations in Heavy-Ion Collisions within Molecular Dynamics with Expansion
No full textWe analyze particle number fluctuations near the critical endpoint of a first-order phase transition using molecular dynamics simulations of the Lennard-Jones fluid. Building on our previous study [V.A. Kuznietsov et al., Phys. Rev. C 105, 044903 (2022)], we incorporate longitudinal collective flow. The scaled variance of particle number distributions in various coordinate and momentum space acceptances is computed through ensemble averaging, confirming previous time-averaging results. We find that significant collective flow is crucial for observing large fluctuations from the critical point in momentum space. These results are discussed in the context of heavy-ion collisions
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Optimization Of Laser Wakefield Acceleration
Get PDFUsing an evolutionary strategy algorithm, we optimize the generalized transformer ration of a laser wakefield accelerator. The algorithm tests several realistic pulse shapes by integrating the fluid wakefield differential equation and it converges to the shape that most efficiently produces a strong accelerating gradient while experiencing minimal distortion.Physic
Recent NA48 results on rare K decays
No full textntensity K S run in 1999. In both cases KL ! mode, followed by the Dalitz decay of , was used as a normalization channel. The data needed to observe and analyze the K S ! decay mode was recorded during a part of the 2000 run with high intensity K S beam and without the charged particle magnetic spectrometer. The corresponding branching ratio was determined relative to the K S ! channel. In order to take into account the detector acceptance and the reconstruction eciency, a detailed Monte Carlo program based on GEANT has been employed. 3 First observation of K S ! As it was recognized in , the decay K S ! can provide valuable test of the chiral structure of the weak vertex. The interest in this particular decay mode is also enhanced by the fact that it has not been observed so far (recently the NA48 experiment put the best upper limit for the decay branching ratio to 3:3 10 using the 1999 high intensity K S data). The most important
A study of anisotropic flow of quarkonia Does everything flow?
No full textInternational audienceIn collisions of ultra-relativistic heavy nuclei, the matter undergoes a phase transition into a deconfined state, known as Quark-Gluon Plasma (QGP). The QGP behaves as an almost perfect fluid, transforming the spatial anisotropies of the initial collision geometry into final-state particle momentum anisotropies, called anisotropic particle flow. Heavy-flavor quarks are created at the initial stage of the collision and experience the entire QGP evolution. Hence, the quarkonia, bound states of heavy-flavor quark-antiquark pairs, are unique probes of the QGP. The study of their anisotropic flow sheds light on the interaction of the heavy-flavor quarks with the QGP as well as on the basic QGP properties. In this seminar, selected recent studies of charmonium and bottomonium production, and in particular their anisotropic flow, in Pb-Pb and p-Pb collisions with the ALICE experiment at the LHC will be shown. The results will be compared to the corresponding measurements of light-flavor and open heavy-flavor particles and to the available theoretical models. The implications for our understanding of the QGP will be discussed
Recent NA48 results on rare kaon decays
No full textRecent NA48 results from detailed studies of and decay modes are presented. The results are based on the data collected with the NA48 detector at the CERN SPS during the 1998-199 9 and 2000 data taking periods, respectively. Prospects for future results on charged kaon decays are briefly described.Recent NA48 results from detailed studies of and decay modes are presented. The results are based on the data collected with the NA48 detector at the CERN SPS during the 1998-199 9 and 2000 data taking periods, respectively. Prospects for future results on charged kaon decays are briefly described
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