14606356
Reeh-Schlieder Theorem for Non-Commutative QFT
It will be shown that the Reeh-Schlieder property holds for states of quantum fields on non-commutative space-times.
17124386
Exact scale invarianmce of the BF-Yang-Mills theory in three dimensions
The ``extended'' BF-Yang-Mills theory in 3 dimensions, which contains a minimally coupled scalar field, is shown to be ultraviolet finite. It obeys a trivial Callan-Symanzik equation, with all β-functions and anomalous dimensions vanishing. The proof is based on an anomaly-free trace identity valid to all orders of perturbation theory.
119528722
Gauge independence of the effective potential revisited
We apply the formalism of extended BRS symmetry to the investigation of the gauge dependence of the effective potential in a spontaneously symmetry broken gauge theory. This formalism, which includes a set of Grassmann parameters defined as the BRS variations of the gauge-fixing parameters, allows us to derive in a quick and unambiguous way the related Nielsen identities, which express the physical gauge independence, in a class of generalized 't Hooft gauges, of the effective potential. We show in particular that the validity of the Nielsen identities does not require any constraint on the gauge-fixing parameters, contrary to some claims found in the literature. We use the method of algebraic renormalization, which leads to results independent of the particular renormalization scheme used.
119307919
Finite one-loop radiative corrections in the Lorentz- and CPT-violating QED extension
We report on our current progress in the study of finite one-loop radiative corrections in the minimal Lorentz- and CPT-violating QED extension.
197441123
On the Geometry of Two-Dimensional Anisotropic Non-Linear Sigma Models
119291520
The ultraviolet and infrared perturbative finiteness of massless QED$_3$
The perturbative ﬁniteness is one of the most peculiarproperties of topological ﬁeld theories in three space-time dimensions [1]. Thanks to a by-product of super-renormalizability and the presence of topological terms,Yang-Mills-Chern-SimonsandBF-Yang-Millstheoriesarealso ﬁnite at all orders in perturbation theory—in the senseof a vanishing function [2]. In spite of not being atopological ﬁeld theory, the massless QED
122075081
Solar neutrino results from borexino
Abstract Borexino is a large-volume liquid scintillator experiment for low energy neutrino detection, operating since May 2007, and installed at the National Laboratory of Gran Sasso. Borexino is the first experiment able to observe in real-time Solar neutrino interactions also in the sub-MeV range. We report with this work the main results achieved in the Solar neutrino sector by Borexino. In particular, we report the results on the measured interaction rates of 7 Be, 8 B, and pep neutrinos, and their impacts on the physics of neutrino oscillations.
11472516
The classification of flaring states of blazars
Aims. The time evolution of the electromagnetic emission from blazars, in particular high-frequency peaked sources (HBLs), displays irregular activity that has not yet been understood. In this work we report a methodology capable of characterizing the time behavior of these variable objects. Methods. The maximum likelihood blocks (MLBs) is a model-independent estimator that subdivides the light curve into time blocks, whose length and amplitude are compatible with states of constant emission rate of the observed source. The MLBs yield the statistical significance in the rate variations and strongly suppresses the noise fluctuations in the light curves. We applied the MLBs for the first time on the long term X-ray light curves (RXTE/ASM) of Mkn 421, Mkn 501, 1ES 1959+650, and 1ES 2155-304, more than 10 years of observational data (1996-2007). Using the MLBs interpretation of RXTE/ASM data, the integrated time flux distribution is determined for each single source considered. We identify in these distributions the characteristic level, as well as the flaring states of the blazars. Results. All the distributions show a significant component at negative flux values, most probably caused by an uncertainty in the background subtraction and by intrinsic fluctuations of RXTE/ASM. This effect concerns in particular short time observations. To quantify the probability that the intrinsic fluctuations give rise to a false identification of a flare, we study a population of very faint sources and their integrated time-flux distribution. We determine duty cycle or fraction of time a source spent in the flaring state of the source Mkn 421, Mkn 501, 1ES 1959+650 and 1ES 2155-304. Moreover, we study the random coincidences between flares and generic sporadic events such as high-energy neutrinos or flares in other wavelengths.
76652777
SOX: Short distance neutrino Oscillations with BoreXino
A bstractThe very low radioactive background of the Borexino detector, its large size, and the well proved capability to detect both low energy electron neutrinos and antineutrinos make an ideal case for the study of short distance neutrino oscillations with artificial sources at Gran Sasso.This paper describes the possible layouts of 51Cr (νe) and 144Ce-144Pr $$ \left( {{{\overline{\nu}}_e}} \right) $$ source experiments in Borexino and shows the expected sensitivity to eV mass sterile neutrinos for three possible different phases of the experiment. Expected results on neutrino magnetic moment, electroweak mixing angle, and couplings to axial and vector currents are shown too.
55691252
Solar neutrino with Borexino: Results and perspectives
Borexino is a unique detector able to perform measurement of solar neutrinos fluxes in the energy region around 1 MeV or below due to its low level of radioactive background. It was constructed at the LNGS underground laboratory with a goal of solar 7Be neutrino flux measurement with 5% precision. The goal has been successfully achieved marking the end of the first stage of the experiment. A number of other important measurements of solar neutrino fluxes have been performed during the first stage. Recently the collaboration conducted successful liquid scintillator repurification campaign aiming to reduce main contaminants in the sub-MeV energy range. With the new levels of radiopurity Borexino can improve existing and challenge a number of new measurements including: improvement of the results on the Solar and terrestrial neutrino fluxes measurements; measurement of pp and CNO solar neutrino fluxes; search for non-standard interactions of neutrino; study of the neutrino oscillations on the short baseline with an artificial neutrino source (search for sterile neutrino) in context of SOX project.
121625849
High precision Be-7 solar neutrinos measurement and day night effect obtained with Borexino
Abstract We report the direct measurement of the 7 Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso and the search for a day–night asymmetry of this interaction rate. The interaction rate of the 0.862 MeV 7 Be neutrinos is 46 ± 1.6 ( stat ) − 1.6 + 1.5 ( syst ) counts/(day · 100 ton). The hypothesis of no oscillation for this solar neutrinos is inconsistent with our measurement at the 5.8 σ C.L. Our result is the first direct measurement of solar neutrinos with an accuracy better than 5%. We report the survival probability for solar ν e in the transition region between matter-enhanced and vacuum-driven oscillations. The measured day night asymmetry is A dn = 0.001 ± 0.012 (stat)±0.007 (syst), in agreement with the predicition of MSW–LMA neutrino [13] oscillations. This result discourages MSW oscillations with mixing parameters in the LOW region at more than 8.5 σ , meaning that this region is, for the first time, strongly rejected without the assumption of CPT symmetry. The result can also be used to constrain some neutrino oscillation scenarios involving new physics.