Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userUniversality of the Weak Interactions, Cabibbo theory and where they led us
191
0
0.0
(
0
)
Added by
Luciano Maiani prof
Publication date
2013
fields
Physics
and research's language is
English
Authors
Luciano Maiani
Ask ChatGPT about the research
No Arabic abstract
Universality of the weak interactions is reviewed, with special emphasis on the origin of the Cabibbo theory of strange particles beta-decays and its role in the discovery of the unified Electroweak Theory. Achievements and present challenges of the Standard Theory of particles interactions are briefly illustrated. As an homage to Nicola Cabibbo, his leading role in the Roma school of theoretical physics and in the italian science in general is reviewed.
rate research
Read More
We present a summary of our understanding of Type Ia Supernova progenitors, mostly discussing the observational approach. The main goal of this review is to provide the non-specialist with a sufficiently comprehensive view of where we stand.
A plethora of ultraviolet completions of the Standard Model have extra U(1) gauge symmetries. In general, the associated massive $Z^prime$ gauge boson can mediate flavor-changing neutral current processes at tree level. We consider a situation where the $Z^prime$ boson couples solely via flavor-changing interactions to quarks and leptons. In this scenario the model parameter space is, in general, quite well constrained by existing flavor bounds. However, we argue that cancellation effects shelter islands in parameter space from strong flavor constraints and that these can be probed by multipurpose collider experiments like ATLAS or CMS as well as LHCb in upcoming runs at the LHC. In still allowed regions of parameter space these scenarios may help to explain the current tension between theory and experiment of $(g-2)_mu$ as well as a small anomaly in $tau$ decays.
For centuries extremely-long grazing fireball displays have fascinated observers and inspired people to ponder about their origins. The Desert Fireball Network (DFN) is the largest single fireball network in the world, covering about one third of Australian skies. This expansive size has enabled us to capture a majority of the atmospheric trajectory of a spectacular grazing event that lasted over90 seconds, penetrated as deep as ~58.5km, and traveled over 1,300 km through the atmosphere before exiting back into interplanetary space. Based on our triangulation and dynamic analyses of the event, we have estimated the initial mass to be at least 60 kg, which would correspond to a30 cm object given a chondritic density (3500 kg m-3). However, this initial mass estimate is likely a lower bound, considering the minimal deceleration observed in the luminous phase. The most intriguing quality of this close encounter is that the meteoroid originated from an Apollo-type orbit and was inserted into a Jupiter-family comet (JFC) orbit due to the net energy gained during the close encounter with the Earth. Based on numerical simulations, the meteoroid will likely spend ~200kyrs on a JFC orbit and have numerous encounters with Jupiter, the first of which will occur in January-March 2025. Eventually the meteoroid will likely be ejected from the Solar System or be flung into a trans-Neptunian orbit.
Quantum mechanics does not provide a clear answer to the question: What was the past of a photon which went through an interferometer? Various welcher weg measurements, delayed-choice which-path experiments and weak-measurements of photons in interferometers presented the past of a photon as a trajectory or a set of trajectories. We have carried out experimental weak measurements of the paths of photons going through a nested Mach-Zehnder interferometer which show a different picture: the past of a photon is not a set of continuous trajectories. The photons tell us that they have been in the parts of the interferometer which they could not have possibly reached! Our results lead to rejection of a common sense approach to the past of a quantum particle. On the other hand, they have a simple explanation within the framework of the two-state vector formalism of quantum theory.
The modification of the effect of interactions of a particle as a function of its pre- and postselected states is analyzed theoretically and experimentally. The universality property of this modification in the case of local interactions of a spatially pre- and postselected particle has been found. It allowed to define an operational approach for characterization of the presence of a quantum particle in a particular place: the way it modifies the effect of local interactions. The experiment demonstrating this universality property provides an efficient interferometric alignment method, in which the beam on a single detector throughout one phase scan yields all misalignment parameters.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
