Exotic Hadrons with Hidden Charm and Strangeness

We investigate on exotic tetraquark hadrons of the kind [cs][cbar sbar] by computing their spectrum and decay modes within a constituent diquark-antidiquark model. We also compare these predictions with the present experimental knowledge.Comment: 6 pages, 2 figures, minor changes made, references adde

Charmed Baryonium

We re-analyze the published data on the Y(4630) --> Lambda_c Lambdabar_c and the Y(4660) --> psi(2S) pi pi with a consistent Ansatz and we find that the two observations are likely to be due to the same state Y_B with M_{Y_B} = 4660.7 +- 8.7 MeV and Gamma_{Y_B} = 61 +- 23 MeV. Under this hypothesis and reanalizing also the e+e- --> J/psi pi pi gamma_ISR spectrum we extract B(Y_B --> Lambda_c Lambdabar_c) / B(Y_B --> psi(2S) pi pi) = 25 +- 7, B(Y_B --> J/psi pi pi) / B(Y_B --> psi(2S) pi pi) J/psi pi pi) / B(Y(4350) --> psi(2S) pi pi) psi(2S) sigma) / B (Y_B --> psi(2S) f_0)=2.0 +- 0.3. These conclusions strongly support the hypothesis of Y_B being the first observation of a charmed baryonium constituted by four quarks. From the analysis of the mass spectrum and the decay properties we show that Y(4350) and Y_B are respectively consistent with the ground state and first radial excitation of the L=1 state.Comment: Corrected phase space normalization in the fit

SuperB physics opportunities

The SuperB project in Tor Vergata (Italy) aims at investigating flavor physics with a data sample two orders of magnitude larger than the B-Factories that have operated for more than a decade. In the era of LHC this represents a unique opportunity to perform complementary indirect searches for new physics effects. In addition its design characteristics make it a flavor factory with an even broader physics reach. This paper summarizes the host of physics opportunities that will be opened by this experiment and the project status

On the Spin of the X(3872)

Whether the much studied X(3872) is an axial or tensor resonance makes an important difference to its interpretation. A recent paper by the BaBar collaboration raised the viable hypothesis that it might be a 2-+ state based on the 3 pions spectrum in the X -> J/psi omega decays. Furthermore, the Belle collaboration published the 2 pions invariant mass and spin-sensitive angular distributions in X -> J/psi rho decays. Starting from a general parametrization of the decay amplitudes for the axial and tensor quantum numbers of the X, we re-analyze the whole set of available data. The level of agreement of the two spin hypotheses with data is interpreted with a rigorous statistical approach based on Monte Carlo simulations in order to be able to combine all the distributions regardless of their different levels of sensitivity to the spin of the X. Our analysis returns a probability of 5.5% and 0.1% for the agreement with data of the 1++ and 2-+ hypotheses, respectively, once we combine the whole information (angular and mass distributions) from both channels. On the other hand, the separate analysis of J/psi rho (angular and mass distributions) and J/psi omega (mass distribution) indicates that the 2-+ assignment is excluded at the 99.9% C.L. by the former case, while the latter excludes at the same level the 1++ hypothesis. There are therefore indications that the two decay modes behave in a different way.Comment: 12 pages, 9 figures, 2 tables. Added angular distributions, which lead to different conclusion

Higher Tetraquark Particles

There are strong arguments favoring a four-quark interpretation of sub-GeV light scalar mesons and the diquark-antidiquark body-plan of the tetraquark seems to provide the most convincing picture. The building diquarks of these particles are assumed to be spin zero objects. In this paper we explore the possibility that radially excited aggregations of spin zero or spin one diquarks might exist and discuss the possibility of the Y(2175) state observed by BaBar and confirmed by BES being one such state.Comment: 8 pages, 4 figure

Silicon Photo-Multiplier radiation hardness tests with a beam controlled neutron source

We report radiation hardness tests performed at the Frascati Neutron Generator on silicon Photo-Multipliers, semiconductor photon detectors built from a square matrix of avalanche photo-diodes on a silicon substrate. Several samples from different manufacturers have been irradiated integrating up to 7x10^10 1-MeV-equivalent neutrons per cm^2. Detector performances have been recorded during the neutron irradiation and a gradual deterioration of their properties was found to happen already after an integrated fluence of the order of 10^8 1-MeV-equivalent neutrons per cm^2.Comment: 7 pages, 6 figures, Submitted to Nucl. Inst. Meth.

Geo-hydrological hazard underlined by toponymy of Italian Military Geographycal Institute maps at 1:25,000 scale. Contributions to the knowledge of floodplain and hillslope dinamycs

Toponymy is a linguistic discipline, which has already been used as a tool for geographical studies in Italy and particularly in Liguria. Geographical studies have already classified the toponyms in several categories: physical geography, human geography and socio-economic geography. By selecting the place names connected to physical geography, we study those suggesting the presence of landslides or floods. We focussed on the Italian Military Geographic Institute maps at 1: 25.000 scale, edited between 1936-1939 and related to a territory approximately located between Genoa and Chiavari, in Ligurian coastal area, and Tortona and Piacenza in Po valley. On the Ligurian slopes we have examined the maps relating to the Polcevera, Bisagno and Entella streams catchments. For the Po side we dealt with maps of the Scrivia and Trebbia rivers catchments: From the Ligurian-Po watershed, these rivers flow into the Adriatic Sea. The place names have been compared with landslide and flood hazard maps of Basin Master Plans for geo-hydrological risk reduction. The toponyms feature a linguistic layer linked to different historical periods. In particular in the study area several layers have been recognized: the ancient Ligurian pre-Roman, Latin, ancient Lombard, vulgar Gaulish-Italic of local languages and Italian terms related to the twentieth century. The first three layers and the last one match in the entire area of study. The vulgar Gaulish-Italic is structured into two Ligurian and Emilian groups: the latter is further splitted into the Oltrepo variants of Tortona and Piacenza. The identified names were distinguished in related-landslides or floods. In addition, the toponyms have been further divided into three linguistic influence areas: Ligurian, from Ligurian Sea up to Novi Ligure and Bobbio, the language of Tortona, downstream of Novi Ligure and Piacenza from Bobbio to Po river. Overall, place names linked to physical geography features represent nearly 25% of toponyms with a density of about 0.5 per km2. Almost half of these are toponyms related to landslides, floods or predisposing factors such as erosion, steepness or water. The names of places linked to landsliding prevail in Liguria, while those related to the waters or floods in the Po areas are located in plain areas or in very gentle slopes. The most common names related to landslides or erosion are \u201cmoggia\u201d, \u201cliggia\u201d or \u201ccrosi\u201d and similar, which respectively mean swampy deposits, landslides or gullies. Names related to floods are \u201criva\u201d, \u201cpiana\u201d \u201cponte\u201d or \u201cisola\u201d which mean respectively edge of fluvial scarp, floodplain, bridge or isle. The comparison with the Basin Master Plan gave satisfying results: we found a good correspondence between names and geo-hydrological hazard. The use of toponyms allowed a geographycal interpretation of the slope and floodplain dynamics. It suggests a possible use of toponymys in land planning activities