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Mini Z' Burst from Relic Supernova Neutrinos and Late Neutrino Masses  [PDF]
Haim Goldberg,Gilad Perez,Ina Sarcevic
Physics , 2005, DOI: 10.1088/1126-6708/2006/11/023
Abstract: In models in which neutrinos are light, due to a low scale of symmetry breaking, additional light bosons are generically present. We show that the interaction between diffuse relic supernova neutrinos (RSN) and the cosmic background neutrinos, via exchange of these light scalars, can result in a dramatic change of the supernova (SN) neutrinos flux. Measurement of this effect with current or future experiments can provide a spectacular direct evidence for the low scale models. We demonstrate how the observation of neutrinos from SN1987A constrains the symmetry breaking scale of the above models. We also discuss how current and future experiments may confirm or further constrain the above models, either by detecting the ``accumulative resonance'' that diffuse RSN go through or via a large suppression of the flux of neutrinos from nearby < O(Mpc) SN bursts.
Bounds on mini-charged neutrinos in the minimal standard model  [PDF]
K. S. Babu,R. R. Volkas
Physics , 1992, DOI: 10.1103/PhysRevD.46.R2764
Abstract: In the minimal Standard Model (MSM) with three generations of quarks and leptons, neutrinos can have tiny charges consistent with electromagnetic gauge invariance. There are three types of non-standard electric charge, given by $Q_{st} + \epsilon(L_i - L_j)$, where $i, j = e, \mu, \tau$ $(i \neq j)$, $Q_{st}$ is standard electric charge, $L_i$ is a family-lepton--number, and $\epsilon$ is an arbitrary parameter which is put equal to zero in the usual incarnation of the MSM. These three non-standard electric charges are of considerable theoretical interest because they are compatible with the MSM Lagrangian and $SU(3)_c \otimes SU(2)_L \otimes U(1)_Y$ gauge anomaly cancellation. The two most conspicuous implications of such non-standard electric charges are the presence of two generations of massless charged neutrinos and a breakdown in electromagnetic universality for $e$, $\mu$ and $\tau$. We use results from (i) charge conservation in $\beta$-decay, (ii) physical consequences of charged atoms in various contexts, (iii) the anomalous magnetic moments of charged leptons, (iv) neutrino-electron scattering, (v) energy loss in red giant and white dwarf stars, and (vi) limits on a cosmologically induced thermal photon mass, to place bounds on $\epsilon$. While the constraints derived for $\epsilon$ 10^{-21}$), the $L_{\mu}-L_{\tau}$ case allows $\epsilon$ to be as large as $10^{-14}$.
The highest energy neutrinos: first evidence for cosmic origin  [PDF]
Francis Halzen
Physics , 2013, DOI: 10.1002/asna.201412058
Abstract: Developments in neutrino astronomy have been to a great extent motivated by the search for the sources of the cosmic rays, leading at a very early stage to the concept of a cubic kilometer neutrino detector. Almost four decades later such an instrument, IceCube, is taking data and has produced the first evidence for a flux of high-energy neutrinos of cosmic origin. After a brief review of the history of the field, we will introduce IceCube and describe the first analysis of data taken with the completed instrument. The atmospheric neutrino flux cannot accommodate an excess of 28 neutrinos observed with energies above 60 TeV. We will briefly speculate on the origin of these events. Readers interested specifically in IceCube results may refer directly to section 3.
Nonlinear mechanisms to Rogue events in the process of interaction between optical filaments  [PDF]
L. M. Kovachev,D. A. Georgieva
Physics , 2015,
Abstract: We investigate two types of nonlinear interaction between collinear femtosecond laser pulses with power slightly above the critical for self-focusing $P_{cr}$. In the first case we study energy exchange between filaments. The model describes this process through degenerate four-photon parametric mixing (FPPM) scheme and requests initial phase difference between the waves. When there are no initial phase difference between the pulses, the FPPM process does not work. In this case it is obtained the second type of interaction as merging between two, three or four filaments in a single filament with higher power. It is found that in the second case the interflow between the filaments has potential of interaction due to cross-phase modulation (CPM).
Best-first Model Merging for Hidden Markov Model Induction  [PDF]
Andreas Stolcke,Stephen M. Omohundro
Computer Science , 1994,
Abstract: This report describes a new technique for inducing the structure of Hidden Markov Models from data which is based on the general `model merging' strategy (Omohundro 1992). The process begins with a maximum likelihood HMM that directly encodes the training data. Successively more general models are produced by merging HMM states. A Bayesian posterior probability criterion is used to determine which states to merge and when to stop generalizing. The procedure may be considered a heuristic search for the HMM structure with the highest posterior probability. We discuss a variety of possible priors for HMMs, as well as a number of approximations which improve the computational efficiency of the algorithm. We studied three applications to evaluate the procedure. The first compares the merging algorithm with the standard Baum-Welch approach in inducing simple finite-state languages from small, positive-only training samples. We found that the merging procedure is more robust and accurate, particularly with a small amount of training data. The second application uses labelled speech data from the TIMIT database to build compact, multiple-pronunciation word models that can be used in speech recognition. Finally, we describe how the algorithm was incorporated in an operational speech understanding system, where it is combined with neural network acoustic likelihood estimators to improve performance over single-pronunciation word models.
First observation of PeV-energy neutrinos with IceCube  [PDF]
IceCube Collaboration,M. G. Aartsen,R. Abbasi,Y. Abdou,M. Ackermann,J. Adams,J. A. Aguilar,M. Ahlers,D. Altmann,J. Auffenberg,X. Bai,M. Baker,S. W. Barwick,V. Baum,R. Bay,J. J. Beatty,S. Bechet,J. Becker Tjus,K. -H. Becker,M. Bell,M. L. Benabderrahmane,S. BenZvi,J. Berdermann,P. Berghaus,D. Berley,E. Bernardini,A. Bernhard,D. Bertrand,D. Z. Besson,G. Binder,D. Bindig,M. Bissok,E. Blaufuss,J. Blumenthal,D. J. Boersma,S. Bohaichuk,C. Bohm,D. Bose,S. B?ser,O. Botner,L. Brayeur,H. -P. Bretz,A. M. Brown,R. Bruijn,J. Brunner,M. Carson,J. Casey,M. Casier,D. Chirkin,A. Christov,B. Christy,K. Clark,F. Clevermann,S. Coenders,S. Cohen,D. F. Cowen,A. H. Cruz Silva,M. Danninger,J. Daughhetee,J. C. Davis,C. De Clercq,S. De Ridder,P. Desiati,M. de With,T. DeYoung,J. C. Díaz-Vélez,M. Dunkman,R. Eagan,B. Eberhardt,J. Eisch,R. W. Ellsworth,S. Euler,P. A. Evenson,O. Fadiran,A. R. Fazely,A. Fedynitch,J. Feintzeig,T. Feusels,K. Filimonov,C. Finley,T. Fischer-Wasels,S. Flis,A. Franckowiak,R. Franke,K. Frantzen,T. Fuchs,T. K. Gaisser,J. Gallagher,L. Gerhardt,L. Gladstone,T. Glüsenkamp,A. Goldschmidt,G. Golup,J. G. Gonzalez,J. A. Goodman,D. Góra,D. Grant,A. Gro?,M. Gurtner,C. Ha,A. Haj Ismail,P. Hallen,A. Hallgren,F. Halzen,K. Hanson,D. Heereman,D. Heinen,K. Helbing,R. Hellauer,S. Hickford,G. C. Hill,K. D. Hoffman,R. Hoffmann,A. Homeier,K. Hoshina,W. Huelsnitz,P. O. Hulth,K. Hultqvist,S. Hussain,A. Ishihara,E. Jacobi,J. Jacobsen,K. Jagielski,G. S. Japaridze,K. Jero,O. Jlelati,B. Kaminsky,A. Kappes
Physics , 2013, DOI: 10.1103/PhysRevLett.111.021103
Abstract: We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of 1.04 $\pm$ 0.16 and 1.14 $\pm$ 0.17 PeV, respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neutral-current $\nu_{e,\mu,\tau}$ ($\bar\nu_{e,\mu,\tau}$) or charged-current $\nu_{e}$ ($\bar\nu_{e}$) interactions within the IceCube detector. The events were discovered in a search for ultra-high energy neutrinos using data corresponding to 615.9 days effective livetime. The expected number of atmospheric background is $0.082 \pm 0.004 \text{(stat)}^{+0.041}_{-0.057} \text{(syst)}$. The probability to observe two or more candidate events under the atmospheric background-only hypothesis is $2.9\times10^{-3}$ ($2.8\sigma$) taking into account the uncertainty on the expected number of background events. These two events could be a first indication of an astrophysical neutrino flux, the moderate significance, however, does not permit a definitive conclusion at this time.
The First Population II Stars Formed in Externally Enriched Mini-halos  [PDF]
Britton Smith,John Wise,Brian O'Shea,Michael Norman,Sadegh Khochfar
Physics , 2015, DOI: 10.1093/mnras/stv1509
Abstract: We present a simulation of the formation of the earliest Population II stars, starting from cosmological initial conditions and ending when metals created in the first supernovae are incorporated into a collapsing gas-cloud. This occurs after a supernova blast-wave collides with a nearby mini-halo, inducing further turbulence that efficiently mixes metals into the dense gas in the center of the halo. The gas that first collapses has been enriched to a metallicity of Z ~ 2e-5 Zsun. Due to the extremely low metallicity, collapse proceeds similarly to metal-free gas until dust cooling becomes efficient at high densities, causing the cloud to fragment into a large number of low mass objects. This external enrichment mechanism provides a plausible origin for the most metal-poor stars observed, such as SMSS J031300.36-670839.3, that appear to have formed out of gas enriched by a single supernova. This mechanism operates on shorter timescales than the time for low-mass mini-halos (M < 5e5 Msun) to recover their gas after experiencing a supernova. As such, metal-enriched stars will likely form first via this channel if the conditions are right for it to occur. We identify a number of other externally enriched halos that may form stars in this manner. These halos have metallicities as high as 0.01 Zsun, suggesting that some members of the first generation of metal-enriched stars may be hiding in plain sight in current stellar surveys.
The first light of Mini-MegaTORTORA wide-field monitoring system  [PDF]
A. Biryukov,G. Beskin,S. Karpov,S. Bondar,E. Ivanov,E. Katkova,A. Perkov,V. Sasyuk
Physics , 2014,
Abstract: Here we describe the first light of the novel 9-channel wide-field optical monitoring system with sub-second temporal resolution, Mini-MegaTORTORA, which is being tested now at Special Astrophysical Observatory on Russian Caucasus. The system is able to observe the sky simultaneously in either wide (~900 square degrees) or narrow (~100 square degrees) fields of view, either in clear light or with any combination of color (Johnson B, V or R) polarimetric filters installed, with exposure times ranging from 100 ms to 100 s. The primary goal of the system is the detection of rapid -- with sub-second characteristic time-scales -- optical transients, but it may be also used for studying the variability of the sky objects on longer time scales.
Mini Mental State Examination (MMSE) in First Episode of Psychosis
Faezeh Tatari,Vahid Farnia,Fariborz Kazemi
Iranian Journal of Psychiatry , 2011,
Abstract: "nObjective: Neurocognitive deficits are now recognized as part of the fundamental disturbances and are a major determinant of functional outcome in psychosis. A cross-sectional association between cognitive deficits and poor social and occupational outcomes has been demonstrated; and treatment of cognitive impairment at the time of the first episode may have the potential to change functional outcomes of the illness. We conducted this study to evaluate cognitive function in first episode of psychosis by the Mini Mental State Examination (MMSE). "nMethod: Sixty two patients with first episode of psychosis were selected and underwent psychiatric interview and took MMSE test. Statistical analysis was done using SPSS-18 software. "nResults: According to MMSE scale, 47 patients (75.8%) showed definite cognitive impairment, 8(12.9%) showed possible impairment ,and 7(11.3%) showed no cognitive impairment. According to MMSE subscale, registration (69.4%) and recall (77.3%) were the most impaired cognitive areas. "nConclusions: The results of the current study indicate significant cognitive impairment in patients with first episode of psychosis. We recommend future studies with larger sample size and control group for further evaluation of cognitive function as early treatment of cognitive impairments may have important implications in the course of illness.
Sterile neutrinos after the first MiniBooNE results
Maltoni, Michele
High Energy Physics - Phenomenology , 2007, DOI: 10.1088/1742-6596/110/8/082011
Abstract: In view of the recent results from the MiniBooNE experiment we revisit the global neutrino oscillation fit to short-baseline neutrino data by adding one, two or three sterile neutrinos with eV-scale masses to the three Standard Model neutrinos. We find that four-neutrino oscillations of the (3+1) type, which have been only marginally allowed before the recent MiniBooNE results, become even more disfavored with the new data. In the framework of so-called (3+2) five-neutrino mass schemes the MiniBooNE results can be nicely reconciled with the LSND appearance evidence thanks to the possibility of CP violation available in such oscillation schemes; however, the tension between appearance and disappearance experiments represents a serious problem in (3+2) schemes, so that these models are ultimately not viable. This tension remains also when a third sterile neutrino is added, and we do not find a significant improvement of the global fit in a (3+3) scheme.
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