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This work presents the ASIMOV Prize for scientific publishing, which was launched in Italy in 2016. The prize aims to bring the young generations closer to scientific culture, through the critical reading of popular science books. The books are selected by a committee that includes scientists, professors, Ph.D. and Ph.D. students, writers, journalists and friends of culture, and most importantly, over 800 school teachers. Students are actively involved in the prize, according to the best practices of public engagement: they read, review the books and vote for them, choosing the winner. The experience is quite successful: 12,000 students from 270 schools all over Italy participated in the last edition. The possibility of replicating this experience in other countries is indicated, as was done in Brazil in 2020 with more than encouraging results., Comment: Presented at ICHEP 2022 (Bologna, 6-13 July 2022)

Even if laboratory practice is essential for all scientific branches of knowledge, it is often neglected at High School, due to lack of time and/or resources. To establish a closer contact between school and experimental sciences, the University Sapienza of Roma and the Istituto Nazionale di Fisica Nucleare (INFN) launched the Lab2Go project, with the goal of spreading laboratory practice among students and teachers in high schools., Comment: in Italian

In the past, the phase-space elementary cell of a non-quantized system was set equal to the third power of the Planck constant; in fact, it is not a necessary assumption. We discuss how the phase space volume, the number of states and the elementary-cell volume of a system of non-interacting N particles, changes when an interaction is switched on and the system becomes or evolves to a system of correlated non-Boltzmann particles and derives the appropriate expressions. Even if we assume that nowadays the volume of the elementary cell is equal to the cube of the Planck constant, h^3, at least for quantum systems, we show that there is a correspondence between different values of h in the past, with important and, in principle, measurable cosmological and astrophysical consequences, and systems with an effective smaller (or even larger) phase-space volume described by non-extensive generalized statistics., Comment: 15 pages, no figures. Published in Entropy 2013, 15, 4319-4333

We have studied the alpha decays of 214Po into 210Pb and of 212Po into 208Pb tagged by the coincidence with the preceding beta decays from 214Bi and 212Bi, respectively. The employed 222Rn, 232Th, and 220Rn sources were sealed inside quartz vials and inserted in the Counting Test Facility at the underground Gran Sasso National Laboratory in Italy. We find that the mean lifetime of 214Po is (236.00 +- 0.42(stat) +- 0.15(syst)) \mu s and that of 212Po is (425.1 +- 0.9(stat) +- 1.2(syst)) ns. Our results, obtained from data with signal-to-background ratio larger than 1000, reduce the overall uncertainties and are compatible with previous measurements., Comment: RevTex, 11 pages, 5 figures, 3 tables. This second version matches the one accepted for publication in EPJA: minor stylistic changes plus a discussion of calibration of TDC time scale

Geo-neutrino studies are based on theoretical estimates of geo-neutrino spectra. We propose a method for a direct measurement of the energy distribution of antineutrinos from decays of long-lived radioactive isotopes. We present preliminary results for the geo-neutrinos from Bi-214 decay, a process which accounts for about one half of the total geo-neutrino signal. The feeding probability of the lowest state of Bi-214 - the most important for geo-neutrino signal - is found to be p_0 = 0.177 \pm 0.004 (stat) ^{+0.003}_{-0.001} (sys), under the hypothesis of Universal Neutrino Spectrum Shape (UNSS). This value is consistent with the (indirect) estimate of the Table of Isotopes (ToI). We show that achievable larger statistics and reduction of systematics should allow to test possible distortions of the neutrino spectrum from that predicted using the UNSS hypothesis. Implications on the geo-neutrino signal are discussed., Comment: 8 pages RevTex format, 8 figures and 2 tables. Submitted to PRC

The deepest hole that has ever been dug is about 12 km deep. Geochemists analyze samples from the Earth's crust and from the top of the mantle. Seismology can reconstruct the density profile throughout all Earth, but not its composition. In this respect, our planet is mainly unexplored. Geo-neutrinos, the antineutrinos from the progenies of U, Th and K40 decays in the Earth, bring to the surface information from the whole planet, concerning its content of natural radioactive elements. Their detection can shed light on the sources of the terrestrial heat flow, on the present composition, and on the origins of the Earth. Geo-neutrinos represent a new probe of our planet, which can be exploited as a consequence of two fundamental advances that occurred in the last few years: the development of extremely low background neutrino detectors and the progress on understanding neutrino propagation. We review the status and the prospects of the field., Comment: 56 pages in RMP ReVTeX format, 36 figures. A few typos corrected and a few minor points changed: resubmitted only to match the final version accepted for publication by Physics Reports

In fusion reactions, the Coulomb barrier selects particles from the high-momentum part of the distribution. Therefore, small variations of the high-momentum tail of the velocity distribution can produce strong effects on fusion rates. In plasmas several potential mechanisms exist that can produce deviations from the standard Maxwell-Boltzmann distribution. Quantum broadening of the energy-momentum dispersion relation of the plasma quasi-particles modifies the high-momentum tail and could explain the fusion-rate enhancement observed in low-energy nuclear reaction experiments., Comment: 9 pages in ReVTeX preprint format, 3 figures, to appear in EPJ B

Ensemble of initial conditions for nonlinear maps can be described in terms of entropy. This ensemble entropy shows an asymptotic linear growth with rate K. The rate K matches the logarithm of the corresponding asymptotic sensitivity to initial conditions \lambda. The statistical formalism and the equality K=\lambda can be extended to weakly chaotic systems by suitable and corresponding generalizations of the logarithm and of the entropy. Using the logistic map as a test case we consider a wide class of deformed statistical description which includes Tsallis, Abe and Kaniadakis proposals. The physical criterion of finite-entropy growth K strongly restricts the suitable entropies. We study how large is the region in parameter space where the generalized description is useful., Comment: RevTeX preprint 10 pages, 4 figures, to appear in The European Physical Journal B

This article illustrates how very small deviations from the Maxwellian exponential tail, while leaving unchanged bulk quantities, can yield dramatic effects on fusion reaction rates and discuss several mechanisms that can cause such deviations., Comment: 9 ReVTex pages including 2 color figures

We find that recent results from the KamLAND collaboration on geologically produced antineutrinos, N(U+Th) = 28+16-15 events, correspond to a radiogenic heat production from Uranium and Thorium decay chains H(U+Th) = 38+35-33 TW. The 99% confidence limit on the geo-neutrino signal translates into the upper bound H(U+Th) < 162 TW, which is much weaker than that claimed by KamLAND, H(U+Th) < 60 TW, based on a too narrow class of geological models. We also performed an analysis of KamLAND data including recent high precision measurements of the C13(\alpha,n)O16 cross section. The result, N(U+Th) = 31+14-13, corroborates the evidence (approx 2.5\sigma) for geo-neutrinos in KamLAND data., Comment: 7 pages (RevTex), 2 figures. Minor changes that match the version accepted for publication on Phys. Lett. B

In preparation to the experimental results which will be available in the future, we study geo-neutrino production for different models of mantle convection and composition. By using global mass balance for the Bulk Silicate Earth, the predicted flux contribution from distant sources in the crust and in the mantle is fixed within a total uncertainty of +-15%. We also discuss regional effects, provided by subducting slabs or plumes near the detector. In four years a five-kton detector operating at a site relatively far from nuclear power plants can achieve measurements of the geo-neutrino signal accurate to within +-5%. It will provide a crucial test of the Bulk Silicate Earth and a direct estimate of the radiogenic contribution to terrestrial heat., Comment: 19 pages, 6 tables, 7 figures; accepted for publication in Earth and Planetary Science Letters

Geo-neutrino detection can determine the amount of long-lived radioactive elements within our planet, thus providing a direct test of the Bulk Silicate Earth (BSE) model and fixing the radiogenic contribution to the terrestrial heat. We present a prediction for the geo-neutrino signal at KamLAND as a function of the Uranium mass in the Earth. The prediction is based on global mass balance, supplemented by a detailed geochemical and geophysical study of the region near the detector. The prediction is weakly dependent on mantle modeling. If BSE is correct, Uranium geo-neutrinos will produce between 25 and 35 events per year and 10^32 protons at Kamioka., Comment: 25 pages, 5 figures; minor changes in reply to referees' comments and APS style requirements, version to appear in PRD. In particular, one less figure, Table III and Table IV have been exchanged and last figure is now first to be referenced in order, note added in proofs on recent KamLAND results

Numerical experiments support the interesting conjecture that statistical methods be applicable not only to fully-chaotic systems, but also at the edge of chaos by using Tsallis' generalizations of the standard exponential and entropy. In particular, the entropy increases linearly and the sensitivity to initial conditions grows as a generalized exponential. We show that this conjecture has actually a broader validity by using a large class of deformed entropies and exponentials and the logistic map as test cases., Comment: 6 pages, 6 figures, uses ws-procs975x65.cls. Proceedings of the Workshop "Complexity, Metastability and Nonextensivity" held in Erice 20-26 July 2004. New version: minor changes (one reference added, typos corrected, positions of figures changed, some comments added)

Asymptotically entropy of chaotic systems increases linearly and the sensitivity to initial conditions is exponential with time: these two behaviors are related. Such relationship is the analogous of and under specific conditions has been shown to coincide with the Pesin identity. Numerical evidences support the proposal that the statistical formalism can be extended to the edge of chaos by using a specific generalization of the exponential and of the Boltzmann-Gibbs entropy. We extend this picture and a Pesin-like identity to a wide class of deformed entropies and exponentials using the logistic map as a test case. The physical criterion of finite-entropy growth strongly restricts the suitable entropies. The nature and characteristics of this generalization are clarified., Comment: ReVTeX, 9 pages, 2 figures. Minor revisions to match the version that will appear in Progress of Theoretical Physics

Geo-neutrino detection will determine the amount of long lived radioactive elements within our planet and fix the debated radiogenic contribution to the terrestrial heat. In addition, it will provide a direct test of the Bulk Silicate Earth model, a fundamental cosmochemical paradigm about the origin of the Earth. Unorthodox models of Earth's core (including the presence of potassium or the possibility of a giant reactor) can also be checked. This short review presents status and prospects of the field., Comment: 7 pages, 2 figures, presented at Neutrino 2004 in Paris

In preparation to the experimental results which will be available in the future, we consider geo-neutrino production in greater detail than in [F. Mantovani et al., arXiv:hep-ph/0309013], putting the basis for a more refined model. We study geo-neutrino production for different models of matter circulation and composition in the mantle. By using global mass balance for the Bulk Silicate Earth, the predicted flux contribution from distant sources in the crust and in the mantle is fixed within +-15% (full range). A detailed geological and geochemical investigation of the region near the detector has to be performed, for reducing the flux uncertainty from fluctuations of the local abundances to the level of the global geochemical error. A five-kton detector operating over four years at a site relatively far from nuclear power plants can measure the geo-neutrino signal with 5% accuracy (1 sigma). It will provide a crucial test of the Bulk Silicate Earth and a direct estimate of the radiogenic contribution to terrestrial heat., Comment: 12 pages, 4 figures, JHEP.cls

We predict geoneutrino fluxes in a reference model based on a detailed description of Earth's crust and mantle and using the best available information on the abundances of uranium, thorium, and potassium inside Earth's layers. We estimate the uncertainties of fluxes corresponding to the uncertainties of the element abundances. In addition to distance integrated fluxes, we also provide the differential fluxes as a function of distance from several sites of experimental interest. Event yields at several locations are estimated and their dependence on the neutrino oscillation parameters is discussed. At Kamioka we predict N(U+Th)=35 +- 6 events for 10^{32} proton yr and 100% efficiency assuming sin^2(2theta)=0.863 and delta m^2 = 7.3 X 10^{-5} eV^2. The maximal prediction is 55 events, obtained in a model with fully radiogenic production of the terrestrial heat flow., Comment: 24 pages, ReVTeX4, plus 7 postscript figures; minor formal changes to match version to be published in PRD

The Super-Kamiokande best global fit, which includes data from SNO, Gallium and Chlorine experiments, results in a hep neutrino contribution to the signals that, even after oscillation, is greater than the SSM prediction. The solar hep neutrino flux that would yield this contribution is four times larger than the one predicted by the SSM. Recent detailed calculations exclude that the astrophysical factor S_{hep}(0) could be wrong by such a large factor. Given the reliability of the temperature and densities profiles inside the Sun, this experimental result indicates that plasma effects are important for this reaction. We show that a slight enhancement of the high-energy tail, enhancement that is of the order of the deviations from the Maxwell-Boltzmann distribution expected in the solar core plasma, produces an increment of the hep rate of the magnitude required. We verified that the other neutrino fluxes remain compatible with experimental signals and SSM predictions. Better measurements of the high-energy tail of the neutrino spectrum would improve our understanding of reaction rates in the solar plasma., Comment: 10 pages, ReVTeX4, no figures

Ultra high energy (UHE) photons can initiate electromagnetic showers in magnetic field. We analyze the two processes that determine the development of the shower, $e^+ e^-$ pair creation and synchrotron radiation, and derive formulae for the angular distribution of the produced particles. These formulae are necessary to study the three-dimensional development of the shower., Comment: RevTex, 13 pages, 4 figures

We calculate the conversion rate of high-energy neutrinos propagating in constant magnetic field into an electron-W pair (nu -> W + e) from the imaginary part of the neutrino self-energy. Using the exact propagators in constant magnetic field, the neutrino self-energy has been calculated to all order in the field within the Weinberg-Salam model. We obtain a compact formula in the limit of B << Bcr = m^2/e. We find that above the process threshold Eth \~ 2.2 10^16 (Bcr / B) eV this contribution to the absorption of neutrinos yields an asymptotic absorption length ~ 1.1 (Bcr / B)^2 (10^{16} eV / E) meters., Comment: 10 pages in RevTeX, 2 figures; published version: two typos corrected, one reference added

We show that moderate deviations from the Maxwell-Boltzmann energy distribution can increase deuterium reaction rates enough to contribute to the heating of Jupiter. These deviations are compatible with the violation of extensivity expected from temperature and density conditions inside Jupiter., Comment: 6 pages, use elsart + 1 encaspulated postscript figure. Submitted to Physica A

We performed two independent counting experiments on a beta-emitting source of Sm151 by measuring the gamma-photon emitted in a fraction of the decays. For counting times ranging from 10**-3 to 5.12*10**4 seconds, our measurements show no evidence of deviations from Poissonian behavior and, in particular, no sign of 1/f noise. These measurements put strong limits on non-Poissonian components of the fluctuations for the subset of decays accompanied by gamma, and corresponding limits for the total number of beta-decays. In particular, the magnitude of a hypothetical flicker floor is strongly bounded also for the beta-decay. This result further constrains theories predicting anomalous fluctuations in nuclear decays., Comment: 10 pages, LaTeX, plus 2 figures added as separate uuencoded compressed postscript files. To appear in Phys. Rev. E 55 (1997)

We show that QCD undergoes dimensional reduction at high temperatures also in the quark sector. In the kinematic region relevant to screening physics, where the lowest Matsubara modes are close to their ``mass-shells'', all static Green's functions involving both quarks and gluons, are reproducible in the high-$T$ limit by a renormalizable three dimensional Lagrangian up to order $\tilde{g}^2(T)\sim 1/ln T$. This three dimensional theory only contains explicitly the lightest bosonic and fermionic Matsubara modes, while the heavier modes correct the tree-level couplings and generate extra local vertices. We also find that the quark degrees of freedom that have been retained in the reduced theory are nonrelativistic in the high-$T$ limit. We then improve our result to order $\tilde{g}^4(T)$ through an explicit nonrelativistic expansion, in the spirit of the heavy quark effective theory. This effective theory is relevant for studying QCD screening phenomena with observables made from quarks, e.g. mesonic and baryonic currents, already at temperatures not much higher than the chiral transition temperature $T_c$., Comment: 29 pages, RevTeX 3.0, plus 7 figures (postscript). This is the revised version that will appear in Nuclear Physics B; modifications to the original version leave results unchanged and mostly better clarify motivations and strategy

We discuss the interpretation of Euclidean correlation functions at finite temperature ($T$) and their relationship with the corresponding real-time Green's functions. The soluble 2+1 dimensional Gross-Neveu model in the large-$N$ limit is used throughout as a working example. First, the real-time bound state, identified as an elementary excitation at finite $T$, is solved. The bound state mass, the dispersion relation at low momenta, the coupling constant and decay constant are calculated. To characterize the structure of the bound state the on-shell form factor is carefully introduced and calculated. Then we examine the corresponding screening state and contrast the screening mass, coupling constant, decay constant and the screening Bethe-Salpeter amplitude with the real-time quantities. We find that, although they can be used as qualitative indicators in the low-$T$ regime, the screening states at finite $T$ in general do not reflect the properties of the corresponding real-time bound states. Besides, other relevant issues, such as the subtlety of the real-time manifestation of conservation laws due to some internal symmetries at $T\ne 0$, the temperature dependence of the pseudoscalar spectral function and its sum rule, and the high-$T$ limit of the screening state and its implications to the dimensional reduction, are also discussed in detail., Comment: 27 pages, ReVTeX, plus 7 postscript figures. Accepted for publication in Physical Review D

The concept of dimensional reduction in the high temperature regime is generalized to static Green's functions of composite operators that contain fermionic fields. The recognition of a natural kinematic region where the lowest Matsubara modes are close to their mass-shell, and the ultraviolet behavior of the running coupling constant of the original theory are crucial for providing the necessary scale hierarchy. The general strategy is illustrated in the asymptotically-free Gross-Neveu model in 1+1 dimensions, where we verify that dimensional reduction occurs to the leading order in $g^2(T)$. We also find, in the same model, that the scale parameter characterizing the dependence on temperature of the coupling constant in the reduced theory, $\Lambda_T$, is considerably smaller than $\Lambda_{\bar{\text{MS}}}$. Implications of our results for QCD are also discussed., Comment: 8 pages, RevTeX 3.0, no figures. To appear in Physics Letters B. Full postscript version available via anonymous ftp (192.84.132.4) at ftp://risc0.ca.infn.it/pub/private/lissia/infnca-th-94-23.ps

Within the framework of the operator product expansion (OPE) and the renormalization group equation (RGE), we show that the temperature and chemical potential dependence of the zeroth moment of a spectral function (SF) is completely determined by the one-loop structure in an asymptotically free theory, and in particular in QCD. Logarithmic corrections are found to play an essential role in the derivation. This exact result constrains the shape of SF's, and implies striking effects near phase transitions. Phenomenological parameterizations of the SF, often used in applications such as the analysis of lattice QCD data or QCD sum rule calculations at finite temperature and baryon density must satisfy these constraints. We also explicitly illustrate in detail the exact sum rule in the Gross-Neveu model., Comment: 26 pages in RevTeX 3.0 plus 7 figures in a separate uuencoded postscript file

We introduce the running coupling constant of QCD in the high temperature phase, $\tilde{g}^2(T)$, through a renormalization scheme where the dimensional reduction is optimal at the one-loop level. We then calculate the relevant scale parameter, $\Lambda_T$, which characterizes the running of $\tilde{g}^2(T)$ with $T$, using the background field method in the static sector. It is found that $\Lambda_T/\Lambda_{\overline{\text{MS}}} =e^{(\gamma_E+1/22)}/(4\pi)\approx 0.148$. We further verify that the coupling $\tilde{g}^2(T)$ is also optimal for lattice perturbative calculations. Our result naturally explains why the high temperature limit of QCD sets in at temperatures as low as a few times the critical temperature. In addition, our $\Lambda_T$ agrees remarkably well with the scale parameter determined from the lattice measurement of the spatial string tension of the SU(2) gauge theory at high $T$., Comment: 13 pages, RevTeX 3.0, no figures. Full postscript version available via anonymous ftp (192.84.132.4) at ftp://risc0.ca.infn.it/pub/private/lissia/infnca-th-94-24.ps

For standard neutrinos, recent solar neutrino results together with the assumption of a nuclearly powered Sun imply severe constraints on the individual components of the total neutrino flux: \Phi_{Be}<0.7*10^9cm^-2 s^-1, \Phi_{CNO}< 0.6*10^9 cm^-2 s^-1, and $64*10^9 cm^-2 s^-1< \Phi_{pp+pep} < 65*10^9 cm^-2 s^-1 (at 1 \sigma level). The bound on \Phi_{Be} is in strong disagreement with the standard solar model prediction \Phi_{Be}^{SSM}\approx 5*10^9 cm^-2 s^-1. We study a large variety of non-standard solar models with low inner temperature, finding that the temperature profiles T(m) follow the homology relationship: T(m)=kT^{SSM}(m), so that they are specified just by the central temperature T_c. There is no value of T_c which can account for all the available experimental results. Even if we only consider the Gallium and Kamiokande results, they remain incompatible. Lowering the cross section p+Be7 \to \gamma+B8 is not a remedy. The shift of the nuclear fusion chain towards the pp-I termination could be induced by a hypothetical low energy resonance in the He3+He3 reaction. This mechanism gives a somehow better, but still bad fit to the combined experimental data. We also discuss what can be learnt from new generation experiments about the properties of neutrinos and of the Sun., Comment: 20 pages in RevTeX 3.0 plus 14 figures in uuencoded postscript files

Within the framework of the operator product expansion (OPE) and the renormalization group equation (RGE), we show that the temperature and chemical potential dependence of the zeroth moment of a spectral function (SF) is completely determined by the one-loop structure of an asymptotically free theory. This exact result constrains the shape of SF's, and implies a highly non-trivial functional form for the SF near second order, or weak first order, phase transitions. Phenomenological parameterizations of the SF, often used in applications such as the analysis of lattice QCD data or QCD sum rule calculations at finite temperature and baryon density, must satisfy these constraints., Comment: 8 pages, no figures, uses RevTeX 3.0. No major changes. Typos fixed and text sharpened. To appear in Phys. Lett. B. Postscript file available at ftp://risc0.ca.infn.it/pub/private/lissia/infnca-th-94-1.ps

The Skyrme effective field theory is tested by evaluating nucleon ground state matrix elements of the correlation functions for two flavor density operators and two pseudoscalar density operators in the Skyrme model and comparing them with results in quenched lattice QCD. The possiblility of using quenched lattice QCD to study higher-order terms in effective field theory is also discussed., Comment: 20 pages in TeX, 6 figures added using "figures", MIT-CTP-2004