Spectroscopy of D Mesons

The scenario of heavy quark meson spectroscopy underwent recently a major revolution, after the observation of BABAR and CLEO, confirmed by BELLE, of \DsJ L=1 excited states, and by further evidences by SELEX. These experimental results have cast doubts on the incarnations of the ideas of Heavy Quark Effective Theory in heavy quark spectroscopy. I shall review the status of experimental data, discuss implications and sketch an outlook.Comment: Invited review talk delivered at HADRON05, Rio de Janeiro (Brasil), August 2005.9 pages, 6 figures. Fixed two wrong reference

Light Quark Spectroscopy Results from FOCUS and E687

Using the FOCUS spectrometer (experiments 687 and 831 at Fermilab) we confirm the existence of a diffractively photoproduced enhancement in $K^+K^-$ at 1750 \mevcc with nearly 100 times the statistics of previous experiments. We also observe a narrow dip structure at 1.9 GeV/c$^2$ in a study of diffractive photoproduction of the $3\pi^+3\pi^-$ final state.Comment: Uses epsfig and lnfprep (included). Five pages, three figures. Presented at the 31st International Conference On High Energy Physics (ICHEP 2002), 24-31 Jul 2002, Amsterdam, The Netherland

From bricks to quasinormal modes: A new perspective on black hole entropy

Calculations of black hole entropy based on the counting of modes of a quantum field propagating in a Schwarzschild background need to be regularized in the vicinity of the horizon. To obtain the Bekenstein-Hawking result the short distance cut-off needs to be fixed by hand. In this note we give an argument for obtaining this cut-off in a natural fashion. We do this by modelling the black hole by its set of quasinormal modes. The horizon then becomes a extended region: the quantum ergosphere. The interaction of the quantum ergosphere and the quantum field provides a natural regularization mechanism. The width of the quantum ergosphere provides the right cut-off for the entropy calculation. We arrive at a dual picture of black hole entropy. The entropy of the black hole is given both by the entropy of the quantum field in the bulk and the dynamical degrees of freedom on the horizon.Comment: Honorable Mention in the 2013 Gravity Research Foundation Essay Competitio

Charm Hadronic Decays From FOCUS: Lessons Learnt

The FOCUS photoproduction experiment took data in the ninenties and produced a wealth of results in charm physics. Some of the studies were seminal for contemporary experiments, and even paved the way for the technology of many charm and beauty analysis tools.Comment: Presented by S.Bianco at CHARM2010, IHEP Beijing. Six pages, 2 figure

Planck-scale dual-curvature lensing and spacetime noncommutativity

It was recently realized that Planck-scale momentum-space curvature, which is expected in some approaches to the quantum-gravity problem, can produce dual-curvature lensing, a feature which mainly affects the direction of observation of particles emitted by very distant sources. Several gray areas remain in our understanding of dual-curvature lensing, including the possibility that it might be just a coordinate artifact and the possibility that it might be in some sense a by product of the better studied dual-curvature redshift. We stress that data reported by the IceCube neutrino telescope should motivate a more vigorous effort of investigation of dual-curvature lensing, and we observe that studies of the recently proposed "$\rho$-Minkowski noncommutative spacetime" could be valuable from this perspective. Through a dedicated $\rho$-Minkowski analysis, we show that dual-curvature lensing is not merely a coordinate artifact and that it can be present even in theories without dual-curvature redshift

The DSR-deformed relativistic symmetries and the relative locality of 3D quantum gravity

Over the last decade there were significant advances in the understanding of quantum gravity coupled to point particles in 3D (2+1-dimensional) spacetime. Most notably it is emerging that the theory can be effectively described as a theory of free particles on a momentum space with anti-deSitter geometry and with noncommutative spacetime coordinates of the type $[x^{\mu},x^{\nu}]=i \hbar \ell \varepsilon^{\mu\nu}_{\phantom{\mu\nu}\rho} x^{\rho}$. We here show that the recently proposed relative-locality curved-momentum-space framework is ideally suited for accommodating these structures characteristic of 3D quantum gravity. Through this we obtain an intuitive characterization of the DSR-deformed Poincar\'e symmetries of 3D quantum gravity, and find that the associated relative spacetime locality is of the type producing dual-gravity lensing.Comment: LaTex, 12 pages, 3 figure

Causality and momentum conservation from relative locality

Theories with a curved momentum space, which became recently of interest in the quantum-gravity literature, can in general violate many apparently robust aspects of our current description of the laws of physics, including relativistic invariance, locality, causality and global momentum conservation. We here explore some aspects of the particularly severe pathologies arising in generic theories with curved momentum space for what concerns causality and momentum conservation. However, we also report results suggesting that when momentum space is maximally symmetric, and the theory is formulated (DSR-)relativistically, with the associated relativity of spacetime locality, momentum is globally conserved and there is no violation of causality.Comment: 20 pages, 6 figures, latex (V2: minor editing

Clocking and Scientific Research: the opinion of the scientific community.

The following chapters assemble the opinions and standpoints of italian and foreign scientists with regard to the assessment of results of research work. This collection was inspired by a manifesto signed by researchers from the Istituto Nazionale di Fisica Nucleare (INFN) and associated universi- ties, which was distributed to the international scientific community. The circumstance giving rise to this intellectual mobilization was the absence of any sign that the promised experimentation to evaluate work performed by government researchers was to start. The scientific community was prompt in giving its support as this document testify. Research activity is assessed according to its content and results. Italian law, however, stipulates that for all government agencies, hence research in- stitutes such as INFN, performance should be monitored using pre-defined objective procedures. For all government institutes and agencies this assess- ment is based on clocking in and out