Notes about Noise in Gravitational Wave Antennas Created by Cosmic Rays

Thermodynamical fluctuations of temperature in mirrors may produce surface fluctuations not only through thermal expansion in mirror body but also through thermal expansion in mirror coating. We analyze the last "surface" effect which can be larger than the first "volume" one due to larger thermal expansion coefficient of coating material and smaller effective volume. In particular, these fluctuations may be important in laser interferometric gravitational antennae.Comment: 9 pages, LaTe

Presupernova g-burst and some consequences of nA e p-reaction

The production of g-burst by absorption of neutrino emission of a collapsing star in its envelope consisting of either hydrogen or carbon; the possible detection of soundless collapse using neutrino and g-ray telescopes, the possible explosion of the hydrogen-containing objects near the collapsing stars, and other consequences of nA e interaction with the protons in the star are discussed

Review of Cosmic Ray experiments with underground detectors

The most important underground detectors addressing Cosmic Ray physics are described, with a special emphasis on the description of the used technology.Comment: Invited talk at 6th International Conference on advanced Technology and Particle Physics, Villa Olmo, Como, Italy, October 5-9, 1998, To be published in Nucl. Phys. B, Proc. Supp

Measurements of neutrino velocity with LVD

The CERN-SPS accelerator has been operated from May 10th to May 24th 2012, with a special bunched-beam structure allowed to measure the neutrino velocity on an event-by-event basis. LVD has detected 48 neutrino events, associated to the beam, with a high absolute time accuracy. These events allow to establish the following limit on the difference between the neutrino speed and the light velocity: −3.8 × 10−6 < (v − c)/c < 3.1 × 10−6 (at 99% C.L.). This value is an order of magnitude lower than previous direct measurements

Search for νμ → νe oscillations with the OPERA experiment in the CNGS beam

A first result of the search for νμ → νe oscillations in the OPERA experiment, located at the Gran Sasso Underground Laboratory, is presented. The experiment looked for the appearance of νe in the CNGS neutrino beam using the data collected in 2008 and 2009. Data are compatible with the non-oscillation hypothesis in the three-flavour mixing model. A further analysis of the same data constrains the non-standard oscillation parameters θnew and Δm2 new. For large Δm2 new values (> 0.1eV 2) , the OPERA 90% C.L. upper limit on sin2(2θnew) based on a Bayesian statistical method reaches the value 7.2 · 10−3

The capability of the existing network of installations for detecting the antineutrino burst from collapsing stars

As the neutrino fluxes can bring information from the internal layers of the collapsing star, the problem of the neutrino burst detection is of importance for both the direct registering of the collapse itself and the investigation of its dynamics. The main characteristics of the neutrino fluxes have been obtained by simulations. The total neutrino flux energy is estimated as 2.5 x 10 to the 53 to 1.4 x 10 to the 54 erg, the energy of NU sub E flux being 10 to the 53 erg. Predictions on neutrino energy spectra are quite different. Two models of the collapse will be used: the model by Bowers and Wilson, hereafter BW, and the model by Nadyozhin and Otroschenko (NO). The NU sub e spectrum in the BW-model reaches the maximum at E max sub NU = 8 MeV. Average energy of NU sub E E sub nu approx. = 10 MeV. The NO-model gives E max sub Nu = 10.5 MeV and E sub nu = 12.6 MeV. The NU sub E-burst duration is DELTA tau sub NU = 20s for the NO-model. As the black hole formation is the result of the star collapse in the BW-model, DELTA tau sub nu is taken to be 5s

Muon pair production by muons and narrow muon bundles underground

We consider the process of muon pair production by high-energy muons and its consequences for the characteristics of muon flux underground. It is shown that the accounting of this process in the muon propagation through the rock results in an additional flux of narrow double- and triple-muon events which is comparable to the conventional flux of narrow muon bundles with low multiplicity

Measuring the Cosmic Ray Muon-Induced Fast Neutron Spectrum by (n,p) Isotope Production Reactions in Underground Detectors

While cosmic ray muons themselves are relatively easy to veto in underground detectors, their interactions with nuclei create more insidious backgrounds via: (i) the decays of long-lived isotopes produced by muon-induced spallation reactions inside the detector, (ii) spallation reactions initiated by fast muon-induced neutrons entering from outside the detector, and (iii) nuclear recoils initiated by fast muon-induced neutrons entering from outside the detector. These backgrounds, which are difficult to veto or shield against, are very important for solar, reactor, dark matter, and other underground experiments, especially as increased sensitivity is pursued. We used fluka to calculate the production rates and spectra of all prominent secondaries produced by cosmic ray muons, in particular focusing on secondary neutrons, due to their importance. Since the neutron spectrum is steeply falling, the total neutron production rate is sensitive just to the relatively soft neutrons, and not to the fast-neutron component. We show that the neutron spectrum in the range between 10 and 100 MeV can instead be probed by the (n, p)-induced isotope production rates 12C(n, p)12B and 16O(n, p)16N in oil- and water-based detectors. The result for 12B is in good agreement with the recent KamLAND measurement. Besides testing the calculation of muon secondaries, these results are also of practical importance, since 12B (T1/2 = 20.2 ms, Q = 13.4 MeV) and 16N (T1/2 = 7.13 s, Q = 10.4 MeV) are among the dominant spallation backgrounds in these detectors

Role of the electromagnetic processes in the high-energy muon production

The muon pair production by gammas in the atmosphere is discussed as a mechanism of “prompt” muon production at very high energies. It is shown that this process dominates over the conventional muon production through pion and kaon decay at energies greater than several PeV