1,721,000 research outputs found
Disoriented Chiral Condensates in Hadron-Hadron Collisions
No full textWe review recent progress in the description and understanding of disoriented chiral condensates. Certain important unsolved issues are underlined, and the preliminary results of our program of investigation of these issues in the framework of the classical linear sigma model are reported. We also briefly review a formalism which could be useful at the full non-equilibrium quantum field theory level of analysis. 1 Presented by G. Amelino-Camelia at the 10th International Conference on Problems of Quantum Field Theory, Alushta, Crimea, Ukraine, May 13-18, 1996. 1 Introduction Recently, in order to explain rare events with a deficit or excess of neutral pions observed in cosmic ray experiments, there has been increased interest in the conjecture that it might be possible to produce disoriented chiral condensates (DCCs), i.e. correlated regions wherein the quark condensate, h0jq L ¯ q R j0i, is chirally rotated from its usual orientation in isospin space. On the theoretical side ther..
Lorentz anomaly and 1+1-dimensional radiating black holes
No full textThe radiation from the black holes of a 1+1-dimensionial chiral quantum gravity model is studied. Most notably, a non-trivial dependence on a renormalization parameter that characterizes the anomaly relations is uncovered in an improved semiclassical approximation scheme; this dependence is not present in the naive semiclassical approximation
Relative-locality geometry for the Snyder model
Get PDFWe investigate the geometry of the energy-momentum space of the Snyder model and of its generalizations according to the definitions proposed in [G. Amelino-Camelia, L. Freidel, J. Kowalski-Glikman and L. Smolin, Phys. Rev. D 84 (2011) 084010], in connection with the theory of relative locality. In this setting, the geometric structures of the energy-momentum space are defined in terms of the deformed composition law of momenta, and we show that in the Snyder case they describe a maximally symmetric space, with vanishing torsion and nonmetricity. However, one cannot apply straightforwardly the phenomenological relations between the geometry and the dynamics postulated in [G. Amelino-Camelia, L. Freidel, J. Kowalski-Glikman and L. Smolin, Phys. Rev. D 84 (2011) 084010], because they were obtained assuming that the leading corrections to the composition law of momenta are quadratic, which is not the case with the Snyder model and its generalizations
Phenomenology of Philosophy of Science: OPERA data
Get PDFI observe that,
as the physics side of the OPERA-anomaly story is apparently unfolding,
there can still be motivation for philosophy of science to analyze
the six months of madness physicists spent chasing the dream of a new
fundamental-physics revolution.
I here mainly report data on studies of the OPERA anomaly
that could be relevant for analyses from the
perspective of phenomenology of philosophy of science.
Most of what I report is an insider's perspective on
the debate that evolved from the original announcement
by the OPERA collaboration of evidence of superluminal neutrinos.
I also sketch out, from a broader perspective,
some of the objectives I view as achievable for
the phenomenology of philosophy of science
A no-pure-boost uncertainty principle from spacetime noncommutativity
No full textWe study boost and space-rotation transformations in k-Minkowski noncommutative spacetime, using the techniques that some of us had previously developed [A. Agostini, G. Amelino-Camelia, M. Arzano, A. Marciano, R.A. Tacchi, hep-th/0607221] for a description of translations in k-Minkowski, which in particular led to the introduction of translation transformation parameters that do not commute with the spacetime coordinates. We find a similar description of boosts and space rotations. which allows us to identify some associated conserved charges. but the form of the commutators between transformation parameters and spacetime coordinates is incompatible with the possibility of a pure boost. (C) 2008 Elsevier B.V. All rights reserved
Anomalous particle-production thresholds through systematic and non-systematic quantum-gravity effects
No full text- …
