57 research outputs found
A FRAMEWORK FOR ARCHITECTURAL HERITAGE HBIM SEMANTIZATION AND DEVELOPMENT
Despite the recognized advantages of the use of BIM in the field of architecture and engineering, the extension of this procedure to the architectural heritage is neither immediate nor critical. The uniqueness and irregularity of historical architecture, on the one hand, and the great quantity of information necessary for the knowledge of architectural heritage, on the other, require appropriate reflections. The aim of this paper is to define a general framework for the use of BIM procedures for architectural heritage. The proposed methodology consists of three different Level of Development (LoD), depending on the characteristics of the building and the objectives of the study: a simplified model with a low geometric accuracy and a minimum quantity of information (LoD 200); a model nearer to the reality but, however, with a high deviation between virtual and real model (LoD 300); a detailed BIM model that reproduce as much as possible the geometric irregularities of the building and is enriched by the maximum quantity of information available (LoD 400)
New physics in \epsilon' from chromomagnetic contributions and limits on Left-Right symmetry
New physics in the chromomagnetic flavor changing transition s->dg* can avoid
the strong GIM suppression of the Standard Model and lead to large
contributions to CP-violating observables, in particular to the epsilon'
parameter, that we address here. We discuss the case of the Left-Right
symmetric models, where this contribution implies bounds on the phases of the
right-handed quark mixing matrix, or in generic models with large phases a
strong bound on the Left-Right symmetry scale. To the leading order, a numeric
formula for epsilon' as a function of the short-distance coefficients for a
wide class of models of new physics is given.Comment: 12 pages, Eq. 12 and related numerics amende
EXPERIENCING THE INACCESSIBLE. A FRAMEWORK FOR VIRTUAL INTERPRETATION AND VISUALIZATION OF REMOTE, RISKY OR RESTRICTED ACCESS HERITAGE PLACES
Abstract. In order to be properly handed down, especially in particular conditions with a high rate of vulnerability, cultural heritage requires documentation and enhancement strategies. The case study presented in this paper is particularly critical not only for the conservation conditions, but especially for the environmental conditions: the Catacombs of San Vittorino have complex conditions of recovery, because of the nature of the artefact and because of the poor lighting of the main environments. For this particularity, a workflow was developed that, in order to achieve the creation of an immersive device navigable by digital viewers such as Oculus Rift or similar, required the start-up of shooting by laser scanning, and then treat the point cloud with different software, in order to obtain a satisfactory result that, in other contexts, could have started easily from a photogrammetric shooting.</p
Gauged Flavor Group with Left-Right Symmetry
We construct an anomaly-free extension of the left-right symmetric model,
where the maximal flavor group is gauged and anomaly cancellation is guaranteed
by adding new vectorlike fermion states. We address the question of the lowest
allowed flavor symmetry scale consistent with data. Because of the mechanism
recently pointed out by Grinstein et al. tree-level flavor changing neutral
currents turn out to play a very weak constraining role. The same occurs, in
our model, for electroweak precision observables. The main constraint turns out
to come from WR-mediated flavor changing neutral current box diagrams,
primarily K - Kbar mixing. In the case where discrete parity symmetry is
present at the TeV scale, this constraint implies lower bounds on the mass of
vectorlike fermions and flavor bosons of 5 and 10 TeV respectively. However,
these limits are weakened under the condition that only SU(2)_R x U(1)_{B-L} is
restored at the TeV scale, but not parity. For example, assuming the SU(2)
gauge couplings in the ratio gR/gL approx 0.7 allows the above limits to go
down by half for both vectorlike fermions and flavor bosons. Our model provides
a framework for accommodating neutrino masses and, in the parity symmetric
case, provides a solution to the strong CP problem. The bound on the lepton
flavor gauging scale is somewhat stronger, because of Big Bang Nucleosynthesis
constraints. We argue, however, that the applicability of these constraints
depends on the mechanism at work for the generation of neutrino masses.Comment: 1+23 pages, 1 table, 5 figures. v3: some more textual fixes (main
change: discussion of Lepton Flavor Violating observables rephrased). Matches
journal versio
Dynamical R-parity Breaking at the LHC
In a class of extensions of the minimal supersymmetric standard model with
(B-L)/left-right symmetry that explains the neutrino masses, breaking R-parity
symmetry is an essential and dynamical requirement for successful gauge
symmetry breaking. Two consequences of these models are: (i) a new kind of
R-parity breaking interaction that protects proton stability but adds new
contributions to neutrinoless double beta decay and (ii) an upper bound on the
extra gauge and parity symmetry breaking scale which is within the large hadron
collider (LHC) energy range. We point out that an important prediction of such
theories is a potentially large mixing between the right-handed charged lepton
() and the superpartner of the right-handed gauge boson (), which leads to a brand new class of R-parity violating interactions of
type and \widetilde{d^c}^\dagger\u^c
e^c. We analyze the relevant constraints on the sparticle mass spectrum and
the LHC signatures for the case with smuon/stau NLSP and gravitino LSP. We note
the "smoking gun" signals for such models to be lepton flavor/number violating
processes: (or ) and
(or ) without
significant missing energy. The predicted multi-lepton final states and the
flavor structure make the model be distinguishable even in the early running of
the LHC.Comment: 30 pages, 13 figures, 6 tables, reference adde
Linear Collider Test of a Neutrinoless Double Beta Decay Mechanism in left-right Symmetric Theories
There are various diagrams leading to neutrinoless double beta decay in
left-right symmetric theories based on the gauge group SU(2)_L x SU(2)_R. All
can in principle be tested at a linear collider running in electron-electron
mode. We argue that the so-called lambda-diagram is the most promising one.
Taking the current limit on this diagram from double beta decay experiments, we
evaluate the relevant cross section e e to W_L W_R, where W_L is the Standard
Model W-boson and W_R the one from SU(2)_R. It is observable if the life-time
of double beta decay and the mass of the W_R are close to current limits. Beam
polarization effects and the high-energy behaviour of the cross section are
also analyzed.Comment: 17 pages, 6 figures. v2: minor changes, references added, to be
published in EPJ
Left-right symmetry at LHC and precise 1-loop low energy data
Despite many tests, even the Minimal Manifest Left-Right Symmetric Model
(MLRSM) has never been ultimately confirmed or falsified. LHC gives a new
possibility to test directly the most conservative version of left-right
symmetric models at so far not reachable energy scales. If we take into account
precise limits on the model which come from low energy processes, like the muon
decay, possible LHC signals are strongly limited through the correlations of
parameters among heavy neutrinos, heavy gauge bosons and heavy Higgs particles.
To illustrate the situation in the context of LHC, we consider the "golden"
process . For instance, in a case of degenerate heavy neutrinos
and heavy Higgs masses at 15 TeV (in agreement with FCNC bounds) we get
fb at TeV which is consistent with muon
decay data for a very limited masses in the range (3008 GeV, 3040 GeV).
Without restrictions coming from the muon data, masses would be in the
range (1.0 TeV, 3.5 TeV). Influence of heavy Higgs particles themselves on the
considered LHC process is negligible (the same is true for the light, SM
neutral Higgs scalar analog). In the paper decay modes of the right-handed
heavy gauge bosons and heavy neutrinos are also discussed. Both scenarios with
typical see-saw light-heavy neutrino mixings and the mixings which are
independent of heavy neutrino masses are considered. In the second case heavy
neutrino decays to the heavy charged gauge bosons not necessarily dominate over
decay modes which include only light, SM-like particles.Comment: 16 pages, 10 figs, KL-KS and new ATLAS limits taken into accoun
Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation
The current status of electric dipole moments of diamagnetic atoms which
involves the synergy between atomic experiments and three different theoretical
areas -- particle, nuclear and atomic is reviewed. Various models of particle
physics that predict CP violation, which is necessary for the existence of such
electric dipole moments, are presented. These include the standard model of
particle physics and various extensions of it. Effective hadron level combined
charge conjugation (C) and parity (P) symmetry violating interactions are
derived taking into consideration different ways in which a nucleon interacts
with other nucleons as well as with electrons. Nuclear structure calculations
of the CP-odd nuclear Schiff moment are discussed using the shell model and
other theoretical approaches. Results of the calculations of atomic electric
dipole moments due to the interaction of the nuclear Schiff moment with the
electrons and the P and time-reversal (T) symmetry violating
tensor-pseudotensor electron-nucleus are elucidated using different
relativistic many-body theories. The principles of the measurement of the
electric dipole moments of diamagnetic atoms are outlined. Upper limits for the
nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained
combining the results of atomic experiments and relativistic many-body
theories. The coefficients for the different sources of CP violation have been
estimated at the elementary particle level for all the diamagnetic atoms of
current experimental interest and their implications for physics beyond the
standard model is discussed. Possible improvements of the current results of
the measurements as well as quantum chromodynamics, nuclear and atomic
calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for
EPJ
Higgs lepton flavour violation: UV completions and connection to neutrino masses
We study lepton violating Higgs (HLFV) decays, first from the effective field theory (EFT) point of view, and then analysing the different high-energy realizations of the operators of the EFT, highlighting the most promising models. We argue why two Higgs doublet models can have a BR(h → τ μ) ∼ 0.01, and why this rate is suppressed in all other realizations including vector-like leptons. We further discuss HLFV in the context of neutrino mass models: in most cases it is generated at one loop giving always BR(h → τ μ) < 10−4 and typically much less, which is beyond experimental reach. However, both the Zee model and extended left-right symmetric models contain extra SU(2) doublets coupled to leptons and could in principle account for the observed excess, with interesting connections between HLFV and neutrino parameters
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