Quantum Markov fields on graphs

We introduce generalized quantum Markov states and generalized d-Markov chains which extend the notion quantum Markov chains on spin systems to that on $C^*$-algebras defined by general graphs. As examples of generalized d-Markov chains, we construct the entangled Markov fields on tree graphs. The concrete examples of generalized d-Markov chains on Cayley trees are also investigated.Comment: 23 pages, 1 figure. accepted to "Infinite Dimensional Anal. Quantum Probability & Related Topics

Dynamical q-deformation in quantum theory and the stochastic limit

A model of particle interacting with quantum field is considered. The model includes as particular cases the polaron model and non-relativistic quantum electrodynamics. We show that the field operators obey q-commutation relations with q depending on time. After the stochastic (or van Hove) limit, due to the nonlinearity, the atomic and field degrees of freedom become entangled in the sense that the field and the atomic variables no longer commute but give rise to a new algebra with new commutation relations replacing the Boson ones. This new algebra allows to give a simple proof of the fact that the non crossing half-planar diagrams give the dominating contribution in a weak coupling regime and to calculate explicitly the correlations associated to the new algebra. The above results depend crucially on the fact that we do not introduce any dipole or multipole approximation.Comment: Latex, 11 page

PQCD Analysis of Parton-Hadron Duality

We propose an extraction of the running coupling constant of QCD in the infrared region from experimental data on deep inelastic inclusive scattering at Bjorken x -> 1. We first attempt a perturbative fit of the data that extends NLO PQCD evolution to large x values and final state invariant mass, W, in the resonance region. We include both target mass corrections and large x resummation effects. These effects are of order O(1/Q^2), and they improve the agreement with the Q^2 dependence of the data. Standard analyses require the presence of additional power corrections, or dynamical higher twists, to achieve a fully quantitative fit. Our analysis, however, is regulated by the value of the strong coupling in the infrared region that enters through large x resummation effects, and that can suppress, or absorb, higher twist effects. Large x data therefore indirectly provide a measurement of this quantity that can be compared to extractions from other observables.Comment: 10 pages, 3 figure

Accessibility and enjoyment of classic theatres: the musealization of archaeological ruins

Intervention on archaeological sites requires a multicriteria approach. One should not lose sight of the problem regarding what to conserve and why in favour of how to conserve. Furthermore, we have to consider that the initiatives of “accessibility and enjoyment of cultural heritage” are created in order to heighten the public’s satisfaction in visiting cultural heritage sites. In this context, the Cultural Accessibility must be interpreted as the amount of information that the public could receive from cultural heritage. A number of possible communication strategies of archaeology will be set out and applied to the case of classical theatres.Intervention on archaeological sites requires a multicriteria approach. One should not lose sight of the problem regarding what to conserve and why in favour of how to conserve. Furthermore, we have to consider that the initiatives of “accessibility and enjoyment of cultural heritage” are created in order to heighten the public’s satisfaction in visiting cultural heritage sites. In this context, the Cultural Accessibility must be interpreted as the amount of information that the public could receive from cultural heritage. A number of possible communication strategies of archaeology will be set out and applied to the case of classical theatres

A "best practice" for inclusive art cities: the case study of the I-Access project

The essay aims to illustrate the results of the I-Access Interreg Italia Malta 2016-20 project, conducted by a partnership led by the Department of Architecture, University of Palermo, with the scientific coordination of Renata Prescia. The project involved the Vucciria district in Palermo and the Bijcceria district in Valletta. Within the range of products that have been created (including database, web platform, mobile apps, protocol), in this essay we want to illustrate the actions implemented to facilitate both physical and cultural accessibility, from the integrated points of view between restoration and exhibition design. They are actions for overcoming of architectural barriers, cultural dissemination actions and museographic-communicative nature actions, including re-evocations of lost or dislocated monuments and artistic works. The proposal is configured as a method for historic cities areas that show problems similar to those of the districts under investigation. For example, the Vucciria, in the face of a high monumental density, shows little liveability, both because many of its monuments, particularly churches, are closed and therefore denied to use, and because there is little motivation for local people to relate with those monuments, considering, among other things, that it is an evolving community. The proposal therefore configures concrete actions to restore the memory for the residents and to recover an identity bond with the context, with concrete implications of attraction for a wide tourism, to offer the district opportunities for regeneration. The project proposals concerned the placement of three urban totems, ten tactile maps in relation to as many churches and the design of two new access ramps to two churches. In their realization as intelligent additions, in contemporary and stimulating ways, compared to interventions characterized by a solipsistic retour au passè, so far carried out in accordance with the philosophy of the current urban plan, they also become an educational opportunity for a dialoguing community

Constraints on the large-x d/u ratio from electron-nucleus scattering at x>1

Recently the ratio of neutron to proton structure functions F_2n/F_2p was extracted from a phenomenological correlation between the strength of the nuclear EMC effect and inclusive electron-nucleus cross section ratios at x>1. Within conventional models of nuclear smearing, this "in-medium correction" (IMC) extraction constrains the size of nuclear effects in the deuteron structure functions, from which the neutron structure function F_2n is usually extracted. The IMC data determine the resulting proton d/u quark distribution ratio, extrapolated to x=1, to be 0.23 +- 0.09 with a 90% confidence level. This is well below the SU(6) symmetry limit of 1/2 and significantly above the scalar diquark dominance limit of 0.Comment: 4 pages, 3 figure

Local asymptotic normality for qubit states

We consider n identically prepared qubits and study the asymptotic properties of the joint state \rho^{\otimes n}. We show that for all individual states \rho situated in a local neighborhood of size 1/\sqrt{n} of a fixed state \rho^0, the joint state converges to a displaced thermal equilibrium state of a quantum harmonic oscillator. The precise meaning of the convergence is that there exist physical transformations T_{n} (trace preserving quantum channels) which map the qubits states asymptotically close to their corresponding oscillator state, uniformly over all states in the local neighborhood. A few consequences of the main result are derived. We show that the optimal joint measurement in the Bayesian set-up is also optimal within the pointwise approach. Moreover, this measurement converges to the heterodyne measurement which is the optimal joint measurement of position and momentum for the quantum oscillator. A problem of local state discrimination is solved using local asymptotic normality.Comment: 16 pages, 3 figures, published versio

Heavy Ion Physics at the LHC

The ion-ion center of mass energies at the LHC will exceed that at RHIC by nearly a factor of 30, providing exciting opportunities for addressing unique physics issues in a completely new energy domain. Some highlights of this new physics domain are presented here. We briefly describe how these collisions will provide new insights into the high density, low momentum gluon content of the nucleus expected to dominate the dynamics of the early state of the system. We then discuss how the dense initial state of the nucleus affects the lifetime and temperature of the produced system. Finally, we explain how the high energy domain of the LHC allows abundant production of `rare' processes, hard probes calculable in perturbative quantum chromodynamics, QCD. At the LHC, high momentum jets and $b \bar b$ bound states, the $\Upsilon$ family, will be produced with high statistics for the first time in heavy ion collisions.Comment: 10 pages, 2 figures, proceedings of INPC 04 in Goteborg, Sweden, July 2004, includes conference style fil

Hadronization dynamics from the spectral representation of the gauge invariant quark propagator

Using the spectral representation of the quark propagator we study the Dirac decomposition of the gauge invariant quark propagator, whose imaginary part describes the hadronization of a quark as this interacts with the vacuum. We then demonstrate the formal gauge invariance of the so-called jet mass, that is of the coefficient of the chiral-odd part of the gauge invariant propagator, that can be expressed in any gauge as the first moment of the chiral-odd quark spectral function. This is therefore revealed to be a \textit{bona fide} QCD observable encoding aspects of the dynamical mass generation in the QCD vacuum, and is furthermore experimentally measurable in specific twist-3 longitudinal-transverse asymmetries in DIS and in semi-inclusive electron-positron collisions. In light-like axial gauges, we also obtain a new sum rule for the spectral function associated with the gauge fixing vector. We finally present a gauge-dependent formula that connects the second moment of the chiral-even coefficient of the quark spectral function to invariant mass generation and final state rescattering in the hadronization of a quark. Finding twist-4 experimental observables sensitive to this quantity is left for future work.Comment: Contribution to DIS2023: XXX International Workshop on Deep-Inelastic Scattering and Related Subjects, Michigan State University, USA, 27-31 March 202

Final state interactions and hadron quenching in cold nuclear matter

I examine the role of final state interactions in cold nuclear matter in modifying hadron production on nuclear targets with leptonic or hadronic beams. I demonstrate the extent to which available experimental data in electron-nucleus collisions can give direct information on final state effects in hadron-nucleus and nucleus-nucleus collisions. For hadron-nucleus collisions, a theoretical estimate based on a parton energy loss model tested in lepton-nucleus collisions shows a large effect on mid-rapidity hadrons at fixed target experiments. At RHIC energy, the effect is large for negative rapidity hadrons, but mild at midrapidity. This final state cold hadron quenching needs to be taken into account in jet tomographic analysis of the medium created in nucleus-nucleus collisions.Comment: 14 pages, 7 figure