Search results for "FOS"
showing 10 items of 15075 documents
Review of proton and nuclear shape fluctuations at high energy
2020
Determining the inner structure of protons and nuclei in terms of their fundamental constituents has been one of the main tasks of high energy nuclear and particle physics experiments. This quest started as a mapping of the (average) parton densities as a function of longitudinal momentum fraction and resolution scale. Recently, the field has progressed to more differential imaging, where one important development is the description of the event-by-event quantum fluctuations in the wave function of the colliding hadron. In this Review, recent developments on the extraction of proton and nuclear transverse geometry with event-by-event fluctuations from collider experiments at high energy is …
Measurement of pyrophosphate concentration in cells by simple terpyridine-Zn(II) probe
2015
Pyrophosphate (PPi) anion is an integral part of our physiology. It partakes in the crucial energy transactions in cells and proffers energy for the harmonious functioning of the cell machinery. Discrepancies in PPi concentrations have been associated with several pathological aberrations such as chronic pyrophosphate arthropathy, calcium pyrophosphate deposition disease, cancer etc. However, there still exists a strong demand for an efficient and specific cell based assay for PPi in order to tap its importance to full potential. Terpyridine-Zn2+ complex (ZnCl2L probe) binds with PPi in 1:3 stoichiometry. This association engenders an emission band (λem) at ~591 nm when excited at 440 nm wi…
Turve- ja metsätalouden vaikutukset kahden metsäjärven ekosysteemiin : paleolimnologinen piileväanalyysi
2015
Tässä tutkielmassa selvitettiin turvetuotannon ja muun maankäytön aiheuttamia ekosysteemimuutoksia kahdessa keskisuomalaisessa metsäjärvessä, Martinjärvessä ja Iso Kivijärvessä. Tutkimus perustui paleolimnologiseen piileväanalyysiin, joka kattoi aikajakson 1600-luvulta nykypäivään. Martinjärven valuma-alueella on turvetuotantoa, mutta vertailujärvenä toimineella Iso Kivijärven valuma-alueella sitä ei ole. Järvien ominaisuudet ovat paljolti samankaltaisia, molemmat ovat matalia, pieniä humusjärviä. Martinjärvellä piilevien monimuotoisuudessa oli suurempaa luonnollista vaihtelua kuin Iso Kivijärvellä. Iso Kivijärvellä monimuotoisuus ja lajimäärät ovat olleet laskussa 1900-luvun ajan aiempiin …
Enhancing identification of causal effects by pruning
2018
Causal models communicate our assumptions about causes and effects in real-world phe- nomena. Often the interest lies in the identification of the effect of an action which means deriving an expression from the observed probability distribution for the interventional distribution resulting from the action. In many cases an identifiability algorithm may return a complicated expression that contains variables that are in fact unnecessary. In practice this can lead to additional computational burden and increased bias or inefficiency of estimates when dealing with measurement error or missing data. We present graphical criteria to detect variables which are redundant in identifying causal effe…
Resolvent estimates for elliptic quadratic differential operators
2011
Sharp resolvent bounds for non-selfadjoint semiclassical elliptic quadratic differential operators are established, in the interior of the range of the associated quadratic symbol.
Selective writing and read-out of a register of static qubits
2013
We propose a setup comprising an arbitrarily large array of static qubits (SQs), which interact with a flying qubit (FQ). The SQs work as a quantum register, which can be written or read-out by means of the FQ through quantum state transfer (QST). The entire system, including the FQ's motional degrees of freedom, behaves quantum mechanically. We demonstrate a strategy allowing for selective QST between the FQ and a single SQ chosen from the register. This is achieved through a perfect mirror located beyond the SQs and suitable modulation of the inter-SQ distances.
Quantum Correlation Dynamics in Controlled Two-Coupled-Qubit Systems
2020
We study and compare the time evolutions of concurrence and quantum discord in a driven system of two interacting qubits prepared in a generic Werner state. The corresponding quantum dynamics is exactly treated and manifests the appearance and disappearance of entanglement. Our analytical treatment transparently unveils the physical reasons for the occurrence of such a phenomenon, relating it to the dynamical invariance of the X structure of the initial state. The quantum correlations which asymptotically emerge in the system are investigated in detail in terms of the time evolution of the fidelity of the initial Werner state.
Vortex dynamics in rotating counterflow and plane Couette and Poiseuille turbulence in superfluid Helium
2008
An equation previously proposed to describe the evolution of vortex line density in rotating counterflow turbulent tangles in superfluid helium is generalized to incorporate nonvanishing barycentric velocity and velocity gradients. Our generalization is compared with an analogous approach proposed by Lipniacki, and with experimental results by Swanson et al. in rotating counterflow, and it is used to evaluate the vortex density in plane Couette and Poiseuille flows of superfluid helium.
Highly occupied gauge theories in 2 + 1 dimensions : a self-similar attractor
2019
Motivated by the boost-invariant Glasma state in the initial stages in heavy-ion collisions, we perform classical-statistical simulations of SU(2) gauge theory in 2+1 dimensional space-time both with and without a scalar field in the adjoint representation. We show that irrespective of the details of the initial condition, the far-from-equilibrium evolution of these highly occupied systems approaches a unique universal attractor at high momenta that is the same for the gauge and scalar sectors. We extract the scaling exponents and the form of the distribution function close to this non-thermal fixed point. We find that the dynamics are governed by an energy cascade to higher momenta with sc…
Experimental Engineering of Arbitrary Qudit States with Discrete-Time Quantum Walks
2019
The capability to generate and manipulate quantum states in high-dimensional Hilbert spaces is a crucial step for the development of quantum technologies, from quantum communication to quantum computation. One-dimensional quantum walk dynamics represents a valid tool in the task of engineering arbitrary quantum states. Here we affirm such potential in a linear-optics platform that realizes discrete-time quantum walks in the orbital angular momentum degree of freedom of photons. Different classes of relevant qudit states in a six-dimensional space are prepared and measured, confirming the feasibility of the protocol. Our results represent a further investigation of quantum walk dynamics in p…