Supernova neutrinos and explosive nucleosynthesis

Energy Technology Data Exchange (ETDEWEB)

Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J.; Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nakamura, K. [Faculty of Science and Engineering, Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

2014-05-09

Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and θ{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

Effects of QCD bound states on dark matter relic abundance

Energy Technology Data Exchange (ETDEWEB)

Liew, Seng Pei [Department of Physics, The University of Tokyo,Bunkyo-ku, Tokyo 113-0033 (Japan); Luo, Feng [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan)

2017-02-17

We study scenarios where there exists an exotic massive particle charged under QCD in the early Universe. We calculate the formation and dissociation rates of bound states formed by pairs of these particles, and apply the results in dark matter (DM) coannihilation scenarios, including also the Sommerfeld effect. We find that on top of the Sommerfeld enhancement, bound-state effects can further significantly increase the largest possible DM masses which can give the observed DM relic abundance, by ∼30–100% with respect to values obtained by considering the Sommerfeld effect only, for the color triplet or octet exotic particles we consider. In particular, it indicates that the Bino DM mass in the right-handed stop-Bino coannihilation scenario in the Minimal Supersymmetric extension of the Standard Model (MSSM) can reach ∼2.5 TeV, even though the potential between the stop and antistop prior to forming a bound state is repulsive. We also apply the bound-state effects in the calculations of relic abundance of long-lived or metastable massive colored particles, and discuss the implications on the BBN constraints and the abundance of a super-weakly interacting DM. The corrections for the bound-state effect when the exotic massive colored particles also carry electric charges, and the collider bounds are also discussed.

Big bang nucleosynthesis and the cosmic neutrino background

International Nuclear Information System (INIS)

Cao Yun; Xing Zhizhong

2013-01-01

We present a brief overview of the neutrino decoupling and big bang nucleosynthesis in the early universe. The big bang relic neutrinos formed one of the backgrounds of the universe. A few possible ways to directly detect the cosmic neutrino background are briefly introduced, and particular attention is paid to the relic neutrino capture on b-decaying nuclei. (authors)

How to detect the cosmic neutrino background?

International Nuclear Information System (INIS)

Ringwald, A.

2003-01-01

A measurement of the big bang relic neutrinos would open a new window to the early universe. We review various possibilities to detect this cosmic neutrino background and substantiate the assertion that - apart from the rather indirect evidence to be gained from cosmology and large-scale structure formation - the annihilation of ultrahigh energy cosmic neutrinos with relic anti-neutrinos (or vice versa) on the Z-resonance is a unique process having sensitivity to the relic neutrinos, if a sufficient flux at E ν i res =M Z 2 /(2m ν i )=4.10 22 eV (0.1 eV/m ν i ) exists. The associated absorption dips in the ultrahigh energy cosmic neutrino spectrum may be searched for at forthcoming neutrino and air shower detectors. The associated protons and photons may have been seen already in form of the cosmic ray events above the Greisen-Zatsepin-Kuzmin cutoff. (orig.)

Common origin of neutrino mass, dark matter and Dirac leptogenesis

Energy Technology Data Exchange (ETDEWEB)

Borah, Debasish [Department of Physics, Indian Institute of Technology Guwahati, Assam 781039 (India); Dasgupta, Arnab, E-mail: dborah@iitg.ernet.in, E-mail: arnab.d@iopb.res.in [Institute of Physics, HBNI, Sachivalaya Marg, Bhubaneshwar 751005 (India)

2016-12-01

We study the possibility of generating tiny Dirac neutrino masses at one loop level through the scotogenic mechanism such that one of the particles going inside the loop can be a stable cold dark matter (DM) candidate. Majorana mass terms of singlet fermions as well as tree level Dirac neutrino masses are prevented by incorporating the presence of additional discrete symmetries in a minimal fashion, which also guarantee the stability of the dark matter candidate. Due to the absence of total lepton number violation, the observed baryon asymmetry of the Universe is generated through the mechanism of Dirac leptogenesis where an equal and opposite amount of leptonic asymmetry is generated in the left and right handed sectors which are prevented from equilibration due to tiny Dirac Yukawa couplings. Dark matter relic abundance is generated through its usual freeze-out at a temperature much below the scale of leptogenesis. We constrain the relevant parameter space from neutrino mass, baryon asymmetry, Planck bound on dark matter relic abundance, and latest LUX bound on spin independent DM-nucleon scattering cross section. We also discuss the charged lepton flavour violation (μ → e γ) and electric dipole moment of electron in this model in the light of the latest experimental data and constrain the parameter space of the model.

Neutrino statistics: elementary problems and some applications

Energy Technology Data Exchange (ETDEWEB)

Kuchowicz, B

1973-01-01

The treatment of neutrinos includes neutrinos in statistical equilibrium, mathematical refinements, application to stars, the relic neutrinos in cosmology, and some unsolved problems and prospects. (JFP)

Prospects for the direct detection of the cosmic neutrino background

International Nuclear Information System (INIS)

Ringwald, Andreas

2009-01-01

The existence of a cosmic neutrino background - the analogue of the cosmic microwave background - is a fundamental prediction of standard big bang cosmology. Up to now, the observational evidence for its existence is rather indirect and rests entirely on cosmological observations of, e.g., the light elemental abundances, the anisotropies in the cosmic microwave background, and the large scale distribution of matter. Here, we review more direct, weak interaction based detection techniques for the cosmic neutrino background in the present epoch and in our local neighbourhood. We show that, with current technology, all proposals are still off by some orders of magnitude in sensitivity to lead to a guaranteed detection of the relic neutrinos. The most promising laboratory search, based on neutrino capture on beta decaying nuclei, may be done in future experiments designed to measure the neutrino mass through decay kinematics.

Prospects for the direct detection of the cosmic neutrino background

International Nuclear Information System (INIS)

Ringwald, Andreas

2009-01-01

The existence of a cosmic neutrino background - the analogue of the cosmic microwave background - is a fundamental prediction of standard big bang cosmology. Up to now, the observational evidence for its existence is rather indirect and rests entirely on cosmological observations of, e.g., the light elemental abundances, the anisotropies in the cosmic microwave background, and the large scale distribution of matter. Here, we review more direct, weak interaction based detection techniques for the cosmic neutrino background in the present epoch and in our local neighbourhood. We show that, with current technology, all proposals are still off by some orders of magnitude in sensitivity to lead to a guaranteed detection of the relic neutrinos. The most promising laboratory search, based on neutrino capture on beta decaying nuclei, may be done in future experiments designed to measure the neutrino mass through decay kinematics. (orig.)

Anti-neutrino imprint in solar neutrino flare

Science.gov (United States)

Fargion, D.

2006-10-01

A future neutrino detector at megaton mass might enlarge the neutrino telescope thresholds revealing cosmic supernova background and largest solar flares (SFs) neutrinos. Indeed the solar energetic (Ep>100 MeV) flare particles (protons, α), while scattering among themselves on solar corona atmosphere must produce prompt charged pions, whose chain decays are source of a solar (electron muon) neutrino 'flare' (at tens or hundreds MeV energy). These brief (minutes) neutrino 'bursts' at largest flare peak may overcome by three to five orders of magnitude the steady atmospheric neutrino noise on the Earth, possibly leading to their detection above detection thresholds (in a full mixed three flavour state). Moreover the birth of anti-neutrinos at a few tens of MeV very clearly flares above a null thermal 'hep' anti-neutrino solar background and also above a tiny supernova relic and atmospheric noise. The largest prompt solar anti-neutrino 'burst' may be well detected in future Super Kamikande (gadolinium implemented) anti-neutrino \\bar\

Big-bang nucleosynthesis and the relic abundance of dark matter in a stau-neutralino coannihilation scenario

International Nuclear Information System (INIS)

Jittoh, Toshifumi; Koike, Masafumi; Sato, Joe; Yamanaka, Masato; Kohri, Kazunori; Shimomura, Takashi

2008-01-01

A scenario of the big-bang nucleosynthesis is analyzed within the minimal supersymmetric standard model, which is consistent with a stau-neutralino coannihilation scenario to explain the relic abundance of dark matter. We find that we can account for the possible discrepancy of the abundance of 7 Li between the observation and the prediction of the big-bang nucleosynthesis by taking the mass of the neutralino as 300 GeV and the mass difference between the stau and the neutralino as (100-120) MeV. We can therefore simultaneously explain the abundance of the dark matter and that of 7 Li by these values of parameters. The lifetime of staus in this scenario is predicted to be O(100-1000) sec.

Effects of sterile neutrinos and an extra dimension on big bang nucleosynthesis

Science.gov (United States)

Jang, Dukjae; Kusakabe, Motohiko; Cheoun, Myung-Ki

2018-02-01

By assuming the existence of extra-dimensional sterile neutrinos in the big bang nucleosynthesis (BBN) epoch, we investigate the sterile neutrino (νs) effects on the BBN and constrain some parameters associated with the νs properties. First, for the cosmic expansion rate, we take into account effects of a five-dimensional bulk and intrinsic tension of the brane embedded in the bulk and constrain a key parameter of the extra dimension by using the observational element abundances. Second, effects of the νs traveling on or off the brane are considered. In this model, the effective mixing angle between a νs and an active neutrino depends on energy, which may give rise to a resonance effect on the mixing angle. Consequently, the reaction rate of the νs can be drastically changed during the cosmic evolution. We estimated abundances and temperature of the νs by solving the rate equation as a function of temperature until the sterile neutrino decoupling. We then find that the relic abundance of the νs is drastically enhanced by the extra dimension and maximized for a characteristic resonance energy Eres≳0.01 GeV . Finally, some constraints related to the νs, i.e., mixing angle and mass difference, are discussed in detail with the comparison of our BBN calculations corrected by the extra-dimensional νs to observational data on light element abundances.

Neutrinos and large-scale structure

International Nuclear Information System (INIS)

Eisenstein, Daniel J.

2015-01-01

I review the use of cosmological large-scale structure to measure properties of neutrinos and other relic populations of light relativistic particles. With experiments to measure the anisotropies of the cosmic microwave anisotropies and the clustering of matter at low redshift, we now have securely measured a relativistic background with density appropriate to the cosmic neutrino background. Our limits on the mass of the neutrino continue to shrink. Experiments coming in the next decade will greatly improve the available precision on searches for the energy density of novel relativistic backgrounds and the mass of neutrinos

Neutrinos and large-scale structure

Energy Technology Data Exchange (ETDEWEB)

Eisenstein, Daniel J. [Daniel J. Eisenstein, Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS #20, Cambridge, MA 02138 (United States)

2015-07-15

I review the use of cosmological large-scale structure to measure properties of neutrinos and other relic populations of light relativistic particles. With experiments to measure the anisotropies of the cosmic microwave anisotropies and the clustering of matter at low redshift, we now have securely measured a relativistic background with density appropriate to the cosmic neutrino background. Our limits on the mass of the neutrino continue to shrink. Experiments coming in the next decade will greatly improve the available precision on searches for the energy density of novel relativistic backgrounds and the mass of neutrinos.

Equilibrium thermodynamics and neutrino decoupling in quasi-metric cosmology

Science.gov (United States)

Østvang, Dag

2018-05-01

The laws of thermodynamics in the expanding universe are formulated within the quasi-metric framework. The quasi-metric cosmic expansion does not directly influence momenta of material particles, so the expansion directly cools null particles only (e.g., photons). Therefore, said laws differ substantially from their counterparts in standard cosmology. Consequently, all non-null neutrino mass eigenstates are predicted to have the same energy today as they had just after neutrino decoupling in the early universe. This indicates that the predicted relic neutrino background is strongly inconsistent with detection rates measured in solar neutrino detectors (Borexino in particular). Thus quasi-metric cosmology is in violent conflict with experiment unless some exotic property of neutrinos makes the relic neutrino background essentially undetectable (e.g., if all massive mass eigenstates decay into "invisible" particles over cosmic time scales). But in absence of hard evidence in favour of the necessary exotic neutrino physics needed to resolve said conflict, the current status of quasi-metric relativity has been changed to non-viable.

Neutrino mass and the origin of galactic magnetic fields

International Nuclear Information System (INIS)

Enqvist, K.; Semikoz, V.; Shukurov, A.; Sokoloff, D.

1993-01-01

We compare two constraints on the strength of the cosmological primordial magnetic field: the one following from the restrictions on the Dirac neutrino spin flip in the early Universe, and another one based on the galactic dynamo theory for the Milky Way (presuming that the seed magnetic field has a relic origin). Since the magnetic field facilitates transitions between left- and right-handed neutrino states, thereby affecting 4 He production at primordial nucleosynthesis, we can obtain a guaranteed upper limit on the strength of the relic magnetic field in the protogalaxy, B c approx-lt 4x10 -9 --3x10 -13 G, depending on the neutrino magnetic moment, if we adopt the MSW explanation of the GALLEX results. On the other hand, models of the dynamo in the Milky Way indicate that the seed magnetic field should be at least 10 -11 --10 -13 G at the protogalaxy scale L=100 kpc. These upper and lower limiting ranges are marginally consistent provided the electron neutrino mass is below 0.3 eV. The results apply to a relic magnetic field produced in the early Universe by any causal mechanism before the nucleosynthesis

Dark-matter sterile neutrinos in models with a gauge singlet in the Higgs sector

International Nuclear Information System (INIS)

Petraki, Kalliopi; Kusenko, Alexander

2008-01-01

Sterile neutrino with mass of several keV can be the cosmological dark matter, can explain the observed velocities of pulsars, and can play an important role in the formation of the first stars. We describe the production of sterile neutrinos in a model with an extended Higgs sector, in which the Majorana mass term is generated by the vacuum expectation value of a gauge-singlet Higgs boson. In this model the relic abundance of sterile neutrinos does not necessarily depend on their mixing angles, the free-streaming length can be much smaller than in the case of warm dark matter produced by neutrino oscillations, and, therefore, some of the previously quoted bounds do not apply. The presence of the gauge singlet in the Higgs sector has important implications for the electroweak phase transition, baryogenesis, and the upcoming experiments at the Large Hadron Collider and a Linear Collider.

From direct detection to relic abundance: the case of proton-philic spin-dependent inelastic Dark Matter

Energy Technology Data Exchange (ETDEWEB)

Scopel, Stefano; Yu, Hyeonhye, E-mail: scopel@sogang.ac.kr, E-mail: skyh2yu@gmail.com [Department of Physics, Sogang University, Seoul (Korea, Republic of)

2017-04-01

We discuss strategies to make inferences on the thermal relic abundance of a Weakly Interacting Massive Particle (WIMP) when the same effective dimension-six operator that explains an experimental excess in direct detection is assumed to drive decoupling at freeze-out, and apply them to the explicit scenario of WIMP inelastic up-scattering with spin-dependent couplings to protons (proton-philic Spin-dependent Inelastic Dark Matter, pSIDM), a phenomenological set-up containing two Dark Matter (DM) particles χ{sub 1} and χ{sub 2} with masses m {sub χ}= m {sub χ{sub 1}} and m {sub χ{sub 2}}= m {sub χ}+δ that we have shown in a previous paper to explain the DAMA effect in compliance with the constraints from other detectors. We also update experimental constraints on pSIDM, extend the analysis to the most general spin-dependent momentum-dependent interactions allowed by non-relativistic Effective Field Theory (EFT), and consider for the WIMP velocity distribution in our Galaxy f ( v ) both a halo-independent approach and a standard Maxwellian. Under these conditions we find that the DAMA effect can be explained in terms of the particle χ{sub 1} in compliance with all the other constraints for all the analyzed EFT couplings and also for a Maxwellian f ( v ). As far as the relic abundance is concerned, we show that the problem of calculating it by using direct detection data to fix the model parameters is affected by a strong sensitivity on f ( v ) and by the degeneracy between the WIMP local density ρ{sub χ} and the WIMP-nucleon scattering cross section, since ρ{sub χ} must be rescaled with respect to the observed DM density in the neighborhood of the Sun when the calculated relic density Ω is smaller than the observed one Ω{sub 0}. As a consequence, a DM direct detection experiment is not directly sensitive to the physical cut-off scale of the EFT, but on some dimensional combination that does not depend on the actual value of Ω. However, such degeneracy

Neutrino mass from Cosmology

CERN Document Server

Lesgourgues, Julien

2012-01-01

Neutrinos can play an important role in the evolution of the Universe, modifying some of the cosmological observables. In this contribution we summarize the main aspects of cosmological relic neutrinos and we describe how the precision of present cosmological data can be used to learn about neutrino properties, in particular their mass, providing complementary information to beta decay and neutrinoless double-beta decay experiments. We show how the analysis of current cosmological observations, such as the anisotropies of the cosmic microwave background or the distribution of large-scale structure, provides an upper bound on the sum of neutrino masses of order 1 eV or less, with very good perspectives from future cosmological measurements which are expected to be sensitive to neutrino masses well into the sub-eV range.

Neutrinos in an expanding Universe

International Nuclear Information System (INIS)

Wigmans, Richard

2015-01-01

The Universe contains several billion neutrinos for each nucleon. In this paper, we follow the history of these relic neutrinos as the Universe expanded. At present, their typical velocity is a few hundred km/s and, therefore, their spectra are affected by gravitational forces. This may have led to a phenomenon that could explain two of todays great mysteries: The large-scale structure of the Universe and the increasing rate at which it expands. (paper)

Two-loop neutrino model with exotic leptons

Science.gov (United States)

Okada, Hiroshi; Orikasa, Yuta

2016-01-01

We propose a two-loop induced neutrino mass model, in which we show some bench mark points to satisfy the observed neutrino oscillation, the constraints of lepton flavor violations, and the relic density in the coannihilation system satisfying the current upper bound on the spin independent scattering cross section with nuclei. We also discuss new sources of muon anomalous magnetic moments.

Multi-component fermionic dark matter and IceCube PeV scale neutrinos in left-right model with gauge unification

Science.gov (United States)

Borah, Debasish; Dasgupta, Arnab; Dey, Ujjal Kumar; Patra, Sudhanwa; Tomar, Gaurav

2017-09-01

We consider a simple extension of the minimal left-right symmetric model (LRSM) in order to explain the PeV neutrino events seen at the IceCube experiment from a heavy decaying dark matter. The dark matter sector is composed of two fermions: one at PeV scale and the other at TeV scale such that the heavier one can decay into the lighter one and two neutrinos. The gauge annihilation cross sections of PeV dark matter are not large enough to generate its relic abundance within the observed limit. We include a pair of real scalar triplets Ω L,R which can bring the thermally overproduced PeV dark matter abundance into the observed range through late time decay and consequent entropy release thereby providing a consistent way to obtain the correct relic abundance without violating the unitarity bound on dark matter mass. Another scalar field, a bitriplet under left-right gauge group is added to assist the heavier dark matter decay. The presence of an approximate global U(1) X symmetry can naturally explain the origin of tiny couplings required for long-lived nature of these decaying particles. We also show, how such an extended LRSM can be incorporated within a non-supersymmetric SO(10) model where the gauge coupling unification at a very high scale naturally accommodate a PeV scale intermediate symmetry, required to explain the PeV events at IceCube.

Neutrino mass in flavor dependent gauged lepton model

Science.gov (United States)

Nomura, Takaaki; Okada, Hiroshi

2018-03-01

We study a neutrino model introducing an additional nontrivial gauged lepton symmetry where the neutrino masses are induced at two-loop level, while the first and second charged-leptons of the standard model are done at one-loop level. As a result of the model structure, we can predict one massless active neutrino, and there is a dark matter candidate. Then we discuss the neutrino mass matrix, muon anomalous magnetic moment, lepton flavor violations, oblique parameters, and relic density of dark matter, taking into account the experimental constraints.

Indirect search for neutralino dark matter with high energy neutrinos

International Nuclear Information System (INIS)

Barger, V.; Halzen, Francis; Hooper, Dan; Kao, Chung

2002-01-01

We investigate the prospects of indirect searches for supersymmetric neutralino dark matter. Relic neutralinos gravitationally accumulate in the Sun and their annihilations produce high energy neutrinos. Muon neutrinos of this origin can be seen in large detectors such as AMANDA, IceCube, and ANTARES. We evaluate the relic density and the detection rate in several models--the minimal supersymmetric model, minimal supergravity, and supergravity with nonuniversal Higgs boson masses at the grand unification scale. We make realistic estimates for the indirect detection rates including effects of the muon detection threshold, quark hadronization, and solar absorption. We find good prospects for detection of neutralinos with mass above 200 GeV

Making the most of the relic density for dark matter searches at the LHC 14 TeV Run

International Nuclear Information System (INIS)

Busoni, Giorgio; Simone, Andrea De; Jacques, Thomas; Morgante, Enrico; Riotto, Antonio

2015-01-01

As the LHC continues to search for new weakly interacting particles, it is important to remember that the search is strongly motivated by the existence of dark matter. In view of a possible positive signal, it is essential to ask whether the newly discovered weakly interacting particle can be be assigned the label 'dark matter'. Within a given set of simplified models and modest working assumptions, we reinterpret the relic abundance bound as a relic abundance range, and compare the parameter space yielding the correct relic abundance with projections of the Run II exclusion regions. Assuming that dark matter is within the reach of the LHC, we also make the comparison with the potential 5σ discovery regions. Reversing the logic, relic density calculations can be used to optimize dark matter searches by motivating choices of parameters where the LHC can probe most deeply into the dark matter parameter space. In the event that DM is seen outside of the region giving the correct relic abundance, we will learn that either thermal relic DM is ruled out in that model, or the DM-quark coupling is suppressed relative to the DM coupling strength to other SM particles

Scalar dark matter with type II seesaw

Directory of Open Access Journals (Sweden)

Arnab Dasgupta

2014-12-01

Full Text Available We study the possibility of generating tiny neutrino mass through a combination of type I and type II seesaw mechanism within the framework of an abelian extension of standard model. The model also provides a naturally stable dark matter candidate in terms of the lightest neutral component of a scalar doublet. We compute the relic abundance of such a dark matter candidate and also point out how the strength of type II seesaw term can affect the relic abundance of dark matter. Such a model which connects neutrino mass and dark matter abundance has the potential of being verified or ruled out in the ongoing neutrino, dark matter, as well as accelerator experiments.

Effective theories for Dark Matter interactions and the neutrino portal paradigm

Energy Technology Data Exchange (ETDEWEB)

Macías, Vannia González; Wudka, José [Department of Physics & Astronomy, University of California Riverside,University Av., Riverside, California 92521-0413 (United States)

2015-07-29

In this article we discuss a general effective-theory description of a multi-component dark sector with an unspecified non-trivial symmetry and its interactions with the Standard Model generated by the exchange of heavy mediators. We then categorize the relevant effective operators given the current experimental sensistivity where the underlying theory is weakly coupled and renormalizable, with neutral mediators: either scalars or fermions. An interesting scenario resulting from this categorization is the neutrino portal, where only fermion mediators are present, and where the dark sector consists of fermions and scalars such that the lightest dark particle is a fermion, this scenario is characterized by having naturally suppressed couplings of the DM to all SM particles except the neutrinos and has received little attention in the literature. We find that there is a wide region in parameter space allowed by the current experimental constraints (relic abundance, direct and indirect detection limits); the cleanest signature of this paradigm is the presence of monochromatic neutrino lines with energy equal to that of the DM mass, but experimental sensitivity would have to be improved significantly before this can be probed.

Neutrino mass, leptogenesis and FIMP dark matter in a U(1)_{B-L} model

Science.gov (United States)

Biswas, Anirban; Choubey, Sandhya; Khan, Sarif

2017-12-01

The Standard Model (SM) is inadequate to explain the origin of tiny neutrino masses, the dark matter (DM) relic abundance and the baryon asymmetry of the Universe. In this work, to address all three puzzles, we extend the SM by a local U(1)_{B-L} gauge symmetry, three right-handed (RH) neutrinos for the cancellation of gauge anomalies and two complex scalars having non-zero U(1)_{B-L} charges. All the newly added particles become massive after the breaking of the U(1)_{B-L} symmetry by the vacuum expectation value (VEV) of one of the scalar fields φ _H. The other scalar field, φ _DM, which does not have any VEV, becomes automatically stable and can be a viable DM candidate. Neutrino masses are generated using the Type-I seesaw mechanism, while the required lepton asymmetry to reproduce the observed baryon asymmetry can be attained from the CP violating out of equilibrium decays of the RH neutrinos in TeV scale. More importantly within this framework, we study in detail the production of DM via the freeze-in mechanism considering all possible annihilation and decay processes. Finally, we find a situation when DM is dominantly produced from the annihilation of the RH neutrinos, which are at the same time also responsible for neutrino mass generation and leptogenesis.

Perspectives for Detection of a Higgsino-like Relic Neutralino

CERN Document Server

Bottino, A; Mignola, G; Olechowski, M; Scopel, S

1996-01-01

It has been conjectured by Ambrosanio, Kane, Kribs, Martin and Mrenna (AKM) that the CDF event $p \\bar p \\to e^+ e^- \\gamma \\gamma + missing E_T$ is due to a decay chain involving two neutralino states (the lightest and the next-to-lightest ones). The lightest neutralino ($\\chi_{AKM}$) has been further considered by Kane and Wells as a candidate for cold dark matter. In this paper we examine the properties of relic $\\chi_{AKM}$'s in their full parameter space, and examine the perspectives for detection by comparing theoretical predictions to sensitivities of various experimental searches. We find that for most regions of the parameter space the detectability of a relic $\\chi_{AKM}$ would require quite substantial improvements in current experimental sensitivities. The measurements of neutrino fluxes from the center of the Earth and of an excess of $\\bar{p}/p$ in cosmic rays are shown to offer some favorable perspectives for investigating a region of the the model.

Dark matter physics in neutrino specific two Higgs doublet model

Energy Technology Data Exchange (ETDEWEB)

Baek, Seungwon; Nomura, Takaaki [School of Physics, Korea Institute for Advanced Study,85 Hoegiro, Dongdaemun-gu, Seoul 02455 (Korea, Republic of)

2017-03-10

Although the seesaw mechanism is a natural explanation for the small neutrino masses, there are cases when the Majorana mass terms for the right-handed neutrinos are not allowed due to symmetry. In that case, if neutrino-specific Higgs doublet is introduced, neutrinos become Dirac particles and their small masses can be explained by its small VEV. We show that the same symmetry, which we assume a global U(1){sub X}, can also be used to explain the stability of dark matter. In our model, a new singlet scalar breaks the global symmetry spontaneously down to a discrete Z{sub 2} symmetry. The dark matter particle, lightest Z{sub 2}-odd fermion, is stabilized. We discuss the phenomenology of dark matter: relic density, direct detection, and indirect detection. We find that the relic density can be explained by a novel Goldstone boson channel or by resonance channel. In the most region of parameter space considered, the direct detections is suppressed well below the current experimental bound. Our model can be further tested in indirect detection experiments such as FermiLAT gamma ray searches or neutrinoless double beta decay experiments.

Neutrino mass, leptogenesis and FIMP dark matter in a U(1){sub B-L} model

Energy Technology Data Exchange (ETDEWEB)

Biswas, Anirban; Khan, Sarif [Harish-Chandra Research Institute, Allahabad (India); Homi Bhabha National Institute, Training School Complex, Mumbai (India); Choubey, Sandhya [Harish-Chandra Research Institute, Allahabad (India); Homi Bhabha National Institute, Training School Complex, Mumbai (India); AlbaNova University Center, Department of Theoretical Physics, School of Engineering Sciences, KTH Royal Institute of Technology, Stockholm (Sweden)

2017-12-15

The Standard Model (SM) is inadequate to explain the origin of tiny neutrino masses, the dark matter (DM) relic abundance and the baryon asymmetry of the Universe. In this work, to address all three puzzles, we extend the SM by a local U(1){sub B-L} gauge symmetry, three right-handed (RH) neutrinos for the cancellation of gauge anomalies and two complex scalars having non-zero U(1){sub B-L} charges. All the newly added particles become massive after the breaking of the U(1){sub B-L} symmetry by the vacuum expectation value (VEV) of one of the scalar fields φ{sub H}. The other scalar field, φ{sub DM}, which does not have any VEV, becomes automatically stable and can be a viable DM candidate. Neutrino masses are generated using the Type-I seesaw mechanism, while the required lepton asymmetry to reproduce the observed baryon asymmetry can be attained from the CP violating out of equilibrium decays of the RH neutrinos in TeV scale. More importantly within this framework, we study in detail the production of DM via the freeze-in mechanism considering all possible annihilation and decay processes. Finally, we find a situation when DM is dominantly produced from the annihilation of the RH neutrinos, which are at the same time also responsible for neutrino mass generation and leptogenesis. (orig.)

Heavy Right-Handed Neutrino Dark Matter and PeV Neutrinos at IceCube

Science.gov (United States)

Bhupal Dev, P. S.; Kazanas, D.; Mohapatra, R. N.; Teplitz, V. L.; Zhang, Yongchao

2016-01-01

We discuss a simple non-supersymmetric model based on the electroweak gauge group SU(2) (sub L) times SU(2) prime times U(1) (Sub B-L) where the lightest of the right-handed neutrinos, which are part of the leptonic doublet of SU(2) prime, play the role of a long-lived unstable dark matter with mass in the multi-Peta-electronvolt range. We use a resonant s-channel annihilation to obtain the correct thermal relic density and relax the unitarity bound on dark matter mass. In this model, there exists a 3-body dark matter decay mode producing tau leptons and neutrinos, which could be the source for the Peta-electronvolt cascade events observed in the IceCube experiment. The model can be tested with more precise flavor information of the highest-energy neutrino events in future data.

Heavy right-handed neutrino dark matter and PeV neutrinos at IceCube

Energy Technology Data Exchange (ETDEWEB)

Dev, P.S. Bhupal [Max-Planck-Institut für Kernphysik,Saupfercheckweg 1, D-69117 Heidelberg (Germany); Kazanas, D. [Astrophysics Science Division, NASA Goddard Space Flight Center,Greenbelt, MD 20771 (United States); Mohapatra, R.N. [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,College Park, MD 20742 (United States); Teplitz, V.L. [Astrophysics Science Division, NASA Goddard Space Flight Center,Greenbelt, MD 20771 (United States); Department of Physics, Southern Methodist University,Dallas, TX 75205 (United States); Zhang, Yongchao [Service de Physique Théorique, Université Libre de Bruxelles,Boulevard du Triomphe, CP225, 1050 Brussels (Belgium); School of Physics, Sun Yat-Sen University,Guangzhou 510275 (China)

2016-08-17

We discuss a simple non-supersymmetric model based on the electroweak gauge group SU(2){sub L}×SU(2){sup ′}×U(1){sub B−L} where the lightest of the right-handed neutrinos, which are part of the leptonic doublet of SU(2){sup ′}, play the role of a long-lived unstable dark matter with mass in the multi-PeV range. We use a resonant s-channel annihilation to obtain the correct thermal relic density and relax the unitarity bound on dark matter mass. In this model, there exists a 3-body dark matter decay mode producing tau leptons and neutrinos, which could be the source for the PeV cascade events observed in the IceCube experiment. The model can be tested with more precise flavor information of the highest-energy neutrino events in future data.

Neutrino oscillations in Gallium and reactor experiments and cosmological effects of a light sterile neutrino

International Nuclear Information System (INIS)

Acero-Ortega, Mario Andres

2009-01-01

data showed a very low compatibility, so we did not use the I.L.L. data for additional analyses. Our fit of the S.R.S. experiment gave very small values of the goodness-of-fit, indicating that the data are incompatible with the oscillations hypothesis, as well as with the no oscillations hypothesis. We do not have any explanation for this result. From the analysis of the Gosgen experiment, we obtained upper limits for the mixing parameters, excluding the region with sin 2 2θ ≥ 0.3 and Δm ≥ 0.05 eV 2 at 3σ C.L.. With the combination of these data with those of Gallium, Bugey and Chooz, we found that the hint of neutrino oscillations persists with 0.03 ≤ sin 2 2θ ≤ 0.07 and Δm 2 ≅ 1.93 eV 2 , with a good compatibility of the data. However, the no oscillations hypothesis cannot be excluded. Motivated by these results, in the second part of this work we studied cosmological constrains on a light non-thermal sterile neutrino. We fitted up-to-date cosmological data with an extended LCDM model, including light relics with a mass in the range 0.1-10 eV. We obtained constrains on the current density and velocity dispersion of those relics, as well as constrains on their mass, assuming that they consist either of early decoupled thermal relics, or of non-resonantly produced sterile neutrinos. Our results are useful to constrain particle-motivated models with three active neutrinos and one extra light species. We got, for instance, that at the 3σ confidence level, a sterile neutrino with mass m s = 2 eV can be accommodated with the data provided that it is thermally distributed with T s /T id ν ≤ 0.8 (with T id ν the temperature of neutrinos in the instantaneous decoupling limit), or is non-resonantly produced with ΔN eff ≤ 0.5. The bounds become dramatically tighter when the mass increases. For m s ≤ 0.9 eV and at the same confidence level, the data is still compatible with a standard thermalized neutrino. (author)

Naturally light Dirac neutrino in Left-Right Symmetric Model

Energy Technology Data Exchange (ETDEWEB)

Borah, Debasish [Department of Physics, Indian Institute of Technology Guwahati, Assam-781039 (India); Dasgupta, Arnab, E-mail: dborah@iitg.ernet.in, E-mail: arnab.d@iopb.res.in [Institute of Physics, HBNI, Sachivalaya Marg, Bhubaneshwar-751005 (India)

2017-06-01

We study the possibility of generating tiny Dirac masses of neutrinos in Left-Right Symmetric Model (LRSM) without requiring the existence of any additional symmetries. The charged fermions acquire masses through a universal seesaw mechanism due to the presence of additional vector like fermions. The neutrinos acquire a one-loop Dirac mass from the same additional vector like charged leptons without requiring any additional discrete symmetries. The model can also be extended by an additional Z {sub 2} symmetry in order to have a scotogenic version of this scenario predicting a stable dark matter candidate. We show that the latest Planck upper bound on the effective number of relativistic degrees of freedom N {sub eff}=3.15 ± 0.23 tightly constrains the right sector gauge boson masses to be heavier than 3.548 TeV . This bound on gauge boson mass also affects the allowed values of right scalar doublet dark matter mass from the requirement of satisfying the Planck bound on dark matter relic abundance. We also discuss the possible implications of such a scenario in charged lepton flavour violation and generating observable electric dipole moment of leptons.

New light Higgs boson and short-baseline neutrino anomalies

Science.gov (United States)

Asaadi, J.; Church, E.; Guenette, R.; Jones, B. J. P.; Szelc, A. M.

2018-04-01

The low-energy excesses observed by the MiniBooNE experiment have, to date, defied a convincing explanation under the standard model even with accommodation for nonzero neutrino mass. In this paper we explore a new oscillation mechanism to explain these anomalies, invoking a light neutrinophilic Higgs boson, conceived to induce a low Dirac neutrino mass in accord with experimental limits. Beam neutrinos forward scattering off of a locally overdense relic neutrino background give rise to a novel matter effect with an energy-specific resonance. An enhanced oscillation around this resonance peak produces flavor transitions which are highly consistent with the MiniBooNE neutrino- and antineutrino-mode data sets. The model provides substantially improved χ2 values beyond either the no-oscillation hypothesis or the more commonly explored 3 +1 sterile neutrino hypothesis. This mechanism would introduce distinctive signatures at each baseline in the upcoming short-baseline neutrino program at Fermilab, presenting opportunities for further exploration.

Research and design progress of the Jinping Neutrino Experiment

Science.gov (United States)

Wang, Zhe

2018-01-01

Thanks to the 2400 m overburden and the long distance to commercial reactors, the China Jinping Underground Laboratory (CJPL) is an ideal site for low background neutrino experiments. The Jinping Neutrino Experiment will perform an in-depth research on solar neutrinos, geo-neutrinos and supernova relic neutrinos. Many efforts were devoted to the R&D of the experimental proposal. A new type of liquid scintillator, with high light-yield and Cherenkov and scintillation separation capability, is being developed. The assay and selection of low radioactive stainless-steel (SST) was carried out. A wide field-of-view of 90 degree and high-geometry-efficiency of 98% light concentrator is developed. At the same time, a 1-ton prototype is constructed and placed underground at Jinping laboratory. The simulation and analysis software, electromagnetic calorimeter function, rock damage zone simulation will also be introduced briefly.

Insights into neutrino decoupling gleaned from considerations of the role of electron mass

Science.gov (United States)

Grohs, E.; Fuller, George M.

2017-10-01

We present calculations showing how electron rest mass influences entropy flow, neutrino decoupling, and Big Bang Nucleosynthesis (BBN) in the early universe. To elucidate this physics and especially the sensitivity of BBN and related epochs to electron mass, we consider a parameter space of rest mass values larger and smaller than the accepted vacuum value. Electromagnetic equilibrium, coupled with the high entropy of the early universe, guarantees that significant numbers of electron-positron pairs are present, and dominate over the number of ionization electrons to temperatures much lower than the vacuum electron rest mass. Scattering between the electrons-positrons and the neutrinos largely controls the flow of entropy from the plasma into the neutrino seas. Moreover, the number density of electron-positron-pair targets can be exponentially sensitive to the effective in-medium electron mass. This entropy flow influences the phasing of scale factor and temperature, the charged current weak-interaction-determined neutron-to-proton ratio, and the spectral distortions in the relic neutrino energy spectra. Our calculations show the sensitivity of the physics of this epoch to three separate effects: finite electron mass, finite-temperature quantum electrodynamic (QED) effects on the plasma equation of state, and Boltzmann neutrino energy transport. The ratio of neutrino to plasma-component energy scales manifests in Cosmic Microwave Background (CMB) observables, namely the baryon density and the radiation energy density, along with the primordial helium and deuterium abundances. Our results demonstrate how the treatment of in-medium electron mass (i.e., QED effects) could translate into an important source of uncertainty in extracting neutrino and beyond-standard-model physics limits from future high-precision CMB data.

Insights into neutrino decoupling gleaned from considerations of the role of electron mass

Directory of Open Access Journals (Sweden)

E. Grohs

2017-10-01

Full Text Available We present calculations showing how electron rest mass influences entropy flow, neutrino decoupling, and Big Bang Nucleosynthesis (BBN in the early universe. To elucidate this physics and especially the sensitivity of BBN and related epochs to electron mass, we consider a parameter space of rest mass values larger and smaller than the accepted vacuum value. Electromagnetic equilibrium, coupled with the high entropy of the early universe, guarantees that significant numbers of electron–positron pairs are present, and dominate over the number of ionization electrons to temperatures much lower than the vacuum electron rest mass. Scattering between the electrons–positrons and the neutrinos largely controls the flow of entropy from the plasma into the neutrino seas. Moreover, the number density of electron–positron-pair targets can be exponentially sensitive to the effective in-medium electron mass. This entropy flow influences the phasing of scale factor and temperature, the charged current weak-interaction-determined neutron-to-proton ratio, and the spectral distortions in the relic neutrino energy spectra. Our calculations show the sensitivity of the physics of this epoch to three separate effects: finite electron mass, finite-temperature quantum electrodynamic (QED effects on the plasma equation of state, and Boltzmann neutrino energy transport. The ratio of neutrino to plasma–component energy scales manifests in Cosmic Microwave Background (CMB observables, namely the baryon density and the radiation energy density, along with the primordial helium and deuterium abundances. Our results demonstrate how the treatment of in-medium electron mass (i.e., QED effects could translate into an important source of uncertainty in extracting neutrino and beyond-standard-model physics limits from future high-precision CMB data.

Sterile Neutrinos, Dark Matter, and Pulsar Velocities in Models with a Higgs Singlet

International Nuclear Information System (INIS)

Kusenko, Alexander

2006-01-01

We identify the range of parameters for which the sterile neutrinos can simultaneously explain the cosmological dark matter and the observed velocities of pulsars. To satisfy all cosmological bounds, the relic sterile neutrinos must be produced sufficiently cold. This is possible in a class of models with a gauge-singlet Higgs boson coupled to the neutrinos. Sterile dark matter can be detected by the x-ray telescopes. The presence of the singlet in the Higgs sector can be tested at the CERN Large Hadron Collider

New viable region of an inert Higgs doublet dark matter model with scotogenic extension

Science.gov (United States)

Borah, Debasish; Gupta, Aritra

2017-12-01

We explore the intermediate dark matter mass regime of the inert Higgs doublet model, approximately between 400 and 550 GeV, which is allowed by latest constraints from direct and indirect detection experiments, but the thermal relic abundance remains suppressed. We extend the model by three copies of right-handed neutrinos, odd under the built-in Z2 symmetry of the model. This discrete Z2 symmetry of the model allows these right-handed neutrinos to couple to the usual lepton doublets through the inert Higgs doublet allowing the possibility of radiative neutrino mass in the scotogenic fashion. Apart from generating nonzero neutrino mass, such an extension can also revive the intermediate dark matter mass regime. The late decay of the lightest right-handed neutrino to dark matter makes it possible for the usual thermally underabundant dark matter in this intermediate mass regime to satisfy the correct relic abundance limit. The revival of this wide intermediate mass range can have relevance not only for direct and indirect search experiments but also for neutrino experiments as the long lifetime of the lightest right-handed neutrino also results in almost vanishing lightest neutrino mass.

Supernova constraints on neutrino oscillation and EoS for proto-neutron star

Energy Technology Data Exchange (ETDEWEB)

Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Mathews, G. J. [Department of Physics, University of Notre Dame, IN 46556 (United States); Nakamura, K. [Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

2014-05-02

Core-collapse supernovae eject huge amount of flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We here discuss how to determine the neutrino temperatures and propose a method to determine still unknown neutrino oscillation parameters, mass hierarchy and θ{sub 13}, simultaneously. Combining the recent experimental constraints on θ{sub 13} with isotopic ratios of the light elements discovered in presolar grains from the Murchison meteorite, we show that our method suggests at a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

Supernova constraints on neutrino oscillation and EoS for proto-neutron star

Science.gov (United States)

Kajino, T.; Aoki, W.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Mathews, G. J.; Nakamura, K.; Shibagaki, S.; Suzuki, T.

2014-05-01

Core-collapse supernovae eject huge amount of flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like 7Li, 11B, 92Nb, 138La and Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We here discuss how to determine the neutrino temperatures and propose a method to determine still unknown neutrino oscillation parameters, mass hierarchy and θ13, simultaneously. Combining the recent experimental constraints on θ13 with isotopic ratios of the light elements discovered in presolar grains from the Murchison meteorite, we show that our method suggests at a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

Observing a light dark matter beam with neutrino experiments

Science.gov (United States)

Deniverville, Patrick; Pospelov, Maxim; Ritz, Adam

2011-10-01

We consider the sensitivity of fixed-target neutrino experiments at the luminosity frontier to light stable states, such as those present in models of MeV-scale dark matter. To ensure the correct thermal relic abundance, such states must annihilate via light mediators, which in turn provide an access portal for direct production in colliders or fixed targets. Indeed, this framework endows the neutrino beams produced at fixed-target facilities with a companion “dark matter beam,” which may be detected via an excess of elastic scattering events off electrons or nuclei in the (near-)detector. We study the high-luminosity proton fixed-target experiments at LSND and MiniBooNE, and determine that the ensuing sensitivity to light dark matter generally surpasses that of other direct probes. For scenarios with a kinetically-mixed U(1)' vector mediator of mass mV, we find that a large volume of parameter space is excluded for mDM˜1-5MeV, covering vector masses 2mDM≲mV≲mη and a range of kinetic mixing parameters reaching as low as κ˜10-5. The corresponding MeV-scale dark matter scenarios motivated by an explanation of the galactic 511 keV line are thus strongly constrained.

Lepton flavor violation and scalar dark matter in a radiative model of neutrino masses

Energy Technology Data Exchange (ETDEWEB)

Esch, Sonja; Klasen, Michael; Lamprea, David R. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Theoretische Physik, Muenster (Germany); Yaguna, Carlos E. [Universidad Pedagogica y Tecnologica de Colombia, Escuela de Fisica, Tunja (Colombia)

2018-02-15

We consider a simple extension of the Standard Model that can account for the dark matter and explain the existence of neutrino masses. The model includes a vector-like doublet of SU(2), a singlet fermion, and two scalar singlets, all of them odd under a new Z{sub 2} symmetry. Neutrino masses are generated radiatively by one-loop processes involving the new fields, while the dark matter candidate is the lightest neutral particle among them. We focus specifically on the case where the dark matter particle is one of the scalars and its relic density is determined by its Yukawa interactions. The phenomenology of this setup, including neutrino masses, dark matter and lepton flavor violation, is analyzed in some detail. We find that the dark matter mass must be below 600 GeV to satisfy the relic density constraint. Lepton flavor violating processes are shown to provide the most promising way to test this scenario. Future μ → 3e and μ-e conversion experiments, in particular, have the potential to probe the entire viable parameter space of this model. (orig.)

Dark matter relics and the expansion rate in scalar-tensor theories

Energy Technology Data Exchange (ETDEWEB)

Dutta, Bhaskar; Jimenez, Esteban [Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Zavala, Ivonne, E-mail: dutta@physics.tamu.edu, E-mail: este1985@physics.tamu.edu, E-mail: e.i.zavalacarrasco@swansea.ac.uk [Department of Physics, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom)

2017-06-01

We study the impact of a modified expansion rate on the dark matter relic abundance in a class of scalar-tensor theories. The scalar-tensor theories we consider are motivated from string theory constructions, which have conformal as well as disformally coupled matter to the scalar. We investigate the effects of such a conformal coupling to the dark matter relic abundance for a wide range of initial conditions, masses and cross-sections. We find that exploiting all possible initial conditions, the annihilation cross-section required to satisfy the dark matter content can differ from the thermal average cross-section in the standard case. We also study the expansion rate in the disformal case and find that physically relevant solutions require a nontrivial relation between the conformal and disformal functions. We study the effects of the disformal coupling in an explicit example where the disformal function is quadratic.

Right-handed neutrino dark matter under the B−L gauge interaction

Energy Technology Data Exchange (ETDEWEB)

Kaneta, Kunio [Center for Theoretical Physics of the Universe, Institute for Basic Science,Daejeon 34051 (Korea, Republic of); Kang, Zhaofeng [School of Physics, Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of); Lee, Hye-Sung [Center for Theoretical Physics of the Universe, Institute for Basic Science,Daejeon 34051 (Korea, Republic of)

2017-02-07

We study the right-handed neutrino (RHN) dark matter candidate in the minimal U(1){sub B−L} gauge extension of the standard model. The U(1){sub B−L} gauge symmetry offers three RHNs which can address the origin of the neutrino mass, the relic dark matter, and the matter-antimatter asymmetry of the universe. The lightest among the three is taken as the dark matter candidate, which is under the B−L gauge interaction. We investigate various scenarios for this dark matter candidate with the correct relic density by means of the freeze-out or freeze-in mechanism. A viable RHN dark matter mass lies in a wide range including keV to TeV scale. We emphasize the sub-electroweak scale light B−L gauge boson case, and identify the parameter region motivated from the dark matter physics, which can be tested with the planned experiments including the CERN SHiP experiment.

Cosmic selection rule for the glueball dark matter relic density

Science.gov (United States)

Soni, Amarjit; Xiao, Huangyu; Zhang, Yue

2017-10-01

We point out a unique mechanism to produce the relic abundance for the glueball dark matter from a gauged SU (N )d hidden sector which is bridged to the standard model sector through heavy vectorlike quarks colored under gauge interactions from both sides. A necessary ingredient of our assumption is that the vectorlike quarks, produced either thermally or nonthermally, are abundant enough to dominate the universe for some time in the early universe. They later undergo dark color confinement and form unstable vectorlike-quarkonium states which annihilate decay and reheat the visible and dark sectors. The ratio of entropy dumped into two sectors and the final energy budget in the dark glueballs is only determined by low energy parameters, including the intrinsic scale of the dark SU (N )d , Λd, and number of dark colors, Nd, but depend weakly on parameters in the ultraviolet such as the vectorlike quark mass or the initial condition. We call this a cosmic selection rule for the glueball dark matter relic density.

Probing Dark Energy via Neutrino and Supernova Observatories

Energy Technology Data Exchange (ETDEWEB)

Hall, Lawrence; Hall, Lawrence J.; Murayama, Hitoshi; Papucci, Michele; Perez, Gilad

2006-07-10

A novel method for extracting cosmological evolution parameters is proposed, using a probe other than light: future observations of the diffuse anti-neutrino flux emitted from core-collapse supernovae (SNe), combined with the SN rate extracted from future SN surveys. The relic SN neutrino differential flux can be extracted by using future neutrino detectors such as Gadolinium-enriched, megaton, water detectors or 100-kiloton detectors of liquid Argon or liquid scintillator. The core-collapse SN rate can be reconstructed from direct observation of SN explosions using future precision observatories. Our method, by itself, cannot compete with the accuracy of the optical-based measurements but may serve as an important consistency check as well as a source of complementary information. The proposal does not require construction of a dedicated experiment, but rather relies on future experiments proposed for other purposes.

Probing Dark Energy via Neutrino and Supernova Observatories

International Nuclear Information System (INIS)

Hall, Lawrence; Hall, Lawrence J.; Murayama, Hitoshi; Papucci, Michele; Perez, Gilad

2006-01-01

A novel method for extracting cosmological evolution parameters is proposed, using a probe other than light: future observations of the diffuse anti-neutrino flux emitted from core-collapse supernovae (SNe), combined with the SN rate extracted from future SN surveys. The relic SN neutrino differential flux can be extracted by using future neutrino detectors such as Gadolinium-enriched, megaton, water detectors or 100-kiloton detectors of liquid Argon or liquid scintillator. The core-collapse SN rate can be reconstructed from direct observation of SN explosions using future precision observatories. Our method, by itself, cannot compete with the accuracy of the optical-based measurements but may serve as an important consistency check as well as a source of complementary information. The proposal does not require construction of a dedicated experiment, but rather relies on future experiments proposed for other purposes

Particle Astrophysics of Neutrinos

Indian Academy of Sciences (India)

Amol Dighe

Energy spectra of neutrino sources. ASPERA. Page 4. Some unique features of neutrinos. The second most abundant particles in the universe. Cosmic microwave background photons: 400 / cm3. Cosmic background neutrinos: 330 / cm3. The lightest massive particles. A million times lighter than the electron. No direct mass ...

Bound-state formation for thermal relic dark matter and unitarity

International Nuclear Information System (INIS)

Harling, Benedict von; Petraki, Kalliopi

2014-01-01

We show that the relic abundance of thermal dark matter annihilating via a long-range interaction, is significantly affected by the formation and decay of dark matter bound states in the early universe, if the dark matter mass is above a few TeV . We determine the coupling required to obtain the observed dark matter density, taking into account both the direct 2-to-2 annihilations and the formation of bound states, and provide an analytical fit. We argue that the unitarity limit on the inelastic cross-section is realized only if dark matter annihilates via a long-range interaction, and we determine the upper bound on the mass of thermal-relic dark matter to be about 197 (139) TeV for (non)-self-conjugate dark matter

1020 eV cosmic-ray and particle physics with kilometer-scale neutrino telescopes

International Nuclear Information System (INIS)

Alvarez-Muniz, J.; Halzen, F.

2001-01-01

We show that a kilometer-scale neutrino observatory, though optimized for TeV to PeV energy, is sensitive to the neutrinos associated with super-EeV sources. These include super-heavy relics, neutrinos associated with the Greisen cutoff, and topological defects which are remnant cosmic structures associated with phase transitions in grand unified gauge theories. It is a misconception that new instruments optimized to EeV energy are required to do this important science, although this is not their primary goal. Because kilometer-scale neutrino telescopes can reject atmospheric backgrounds by establishing the very high energy of the signal events, they have sensitivity over the full solid angle, including the horizon where most of the signal is concentrated. This is important because up-going neutrino-induced muons, routinely considered in previous calculations, are absorbed by the Earth

Thermal dark matter through the Dirac neutrino portal

Science.gov (United States)

Batell, Brian; Han, Tao; McKeen, David; Haghi, Barmak Shams Es

2018-04-01

We study a simple model of thermal dark matter annihilating to standard model neutrinos via the neutrino portal. A (pseudo-)Dirac sterile neutrino serves as a mediator between the visible and the dark sectors, while an approximate lepton number symmetry allows for a large neutrino Yukawa coupling and, in turn, efficient dark matter annihilation. The dark sector consists of two particles, a Dirac fermion and complex scalar, charged under a symmetry that ensures the stability of the dark matter. A generic prediction of the model is a sterile neutrino with a large active-sterile mixing angle that decays primarily invisibly. We derive existing constraints and future projections from direct detection experiments, colliders, rare meson and tau decays, electroweak precision tests, and small scale structure observations. Along with these phenomenological tests, we investigate the consequences of perturbativity and scalar mass fine tuning on the model parameter space. A simple, conservative scheme to confront the various tests with the thermal relic target is outlined, and we demonstrate that much of the cosmologically-motivated parameter space is already constrained. We also identify new probes of this scenario such as multibody kaon decays and Drell-Yan production of W bosons at the LHC.

How neutrino oscillations can induce an effective neutrino number of less than three during big bang nucleosynthesis

International Nuclear Information System (INIS)

Foot, R.; Volkas, R.R.

1997-01-01

Ordinary-sterile neutrino oscillations can generate significant neutrino asymmetry in the early Universe. In this paper we extend this work by computing the evolution of neutrino asymmetries and light element abundances during the big bang nucleosynthesis (BBN) epoch. We show that a significant electron-neutrino asymmetry can be generated in a way that is approximately independent of the oscillation parameters δm 2 and sin 2 2θ for a range of parameters in an interesting class of models. The numerical value of the asymmetry leads to the prediction that the effective number of neutrino flavors during BBN is either about 2.5 or 3.4, depending on the sign of the asymmetry. Interestingly, one class of primordial deuterium abundance data favors an effective number of neutrino flavors during the epoch of BBN of less than 3. copyright 1997 The American Physical Society

External meeting: KATRIN - direct measurement of neutrino masses with sub-eV sensitivity

CERN Multimedia

2007-01-01

GENEVA UNIVERSITY - ECOLE DE PHYSIQUE Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet 1211 GENEVE 4 - Tél : 022 379 62 73 - Fax: 022 379 69 92 Wednesday 18 April 2007 PARTICLE PHYSICS SEMINAR at 17:00 - Stückelberg Auditorium KATRIN - direct measurement of neutrino masses with sub-eV sensitivity by Prof. Guido Drexlin, Karlsruhe Institute of Technology KIT The major scientific objective of the international Karlsruhe Tritum Neutrino (KATRIN) Experiment is the model independent measurement of the electron neutrino mass in tritium beta decay with a sensitivity of 200 meV. In the cosmological context, this allows an investigation of whether massive relic neutrinos left over from the Big Bang play a specific role as hot dark matter in the evolution of large scale structures of the universe. In particle physics KATRIN will allow for discrimination between different neutrino mass models (either of quasi-degenerate or hierarchical pattern).The key components of KATRIN comprise...

Nonlinear Dynamics of the Cosmic Neutrino Background

Science.gov (United States)

Inman, Derek

At least two of the three neutrino species are known to be massive, but their exact masses are currently unknown. Cosmic neutrinos decoupled from the rest of the primordial plasma early on when the Universe was over a billion times hotter than it is today. These relic particles, which have cooled and are now non-relativistic, constitute the Cosmic Neutrino Background and permeate the Universe. While they are not observable directly, their presence can be inferred by measuring the suppression of the matter power spectrum. This suppression is a linear effect caused by the large thermal velocities of neutrinos, which prevent them from collapsing gravitationally on small scales. Unfortunately, it is difficult to measure because of degeneracies with other cosmological parameters and biases arising from the fact that we typically observe point-like galaxies rather than a continous matter field. It is therefore important to look for new effects beyond linear suppression that may be more sensitive to neutrinos. This thesis contributes to the understanding of the nonlinear dynamics of the cosmological neutrino background in the following ways: (i) the development of a new injection scheme for neutrinos in cosmological N-body simulations which circumvents many issues associated with simulating neutrinos at large redshifts, (ii) the numerical study of the relative velocity field between cold dark matter and neutrinos including its reconstruction from density fields, (iii) the theoretical description of neutrinos as a dispersive fluid and its use in modelling the nonlinear evolution of the neutrino density power spectrum, (iv) the derivation of the dipole correlation function using linear response which allows for the Fermi-Dirac velocity distribution to be properly included, and (v) the numerical study and detection of the dipole correlation function in the TianNu simulation. In totality, this thesis is a comprehensive study of neutrino density and velocity fields that may

Supernova nucleosynthesis and the physics of neutrino oscillation

Energy Technology Data Exchange (ETDEWEB)

Kajino, Toshitaka [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan) and Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan)

2012-11-20

We studied the explosive nucleosynthesis in core-collapse supernovae and found that several isotopes of rare elements like {sup 7}Li, {sup 11}B, {sup 138}La, {sup 180}Ta and others are predominantly produced by the neutrino interactions with several abundant nuclei. These isotopes are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect. We here first study how to know the suitable average neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the neutrino oscillation effects on their abundances, and propose a new novel method to determine the neutrino oscillation parameters, {theta}{sub 13} and mass hierarchy, simultaneously. There is recent evidence that some SiC X grains from the Murchison meteorite may contain supernova-produced neutrino-process {sup 11}B and {sup 7}Li encapsulated in the grains. Combining the recent experimental constraints on {theta}{sub 13}, we show that although the uncertainties are still large, our method hints at a marginal preference for an inverted neutrino mass hierarchy for the first time.

Supernova nucleosynthesis and the physics of neutrino oscillation

Science.gov (United States)

Kajino, Toshitaka

2012-11-01

We studied the explosive nucleosynthesis in core-collapse supernovae and found that several isotopes of rare elements like 7Li, 11B, 138La, 180Ta and others are predominantly produced by the neutrino interactions with several abundant nuclei. These isotopes are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect. We here first study how to know the suitable average neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the neutrino oscillation effects on their abundances, and propose a new novel method to determine the neutrino oscillation parameters, θ13 and mass hierarchy, simultaneously. There is recent evidence that some SiC X grains from the Murchison meteorite may contain supernova-produced neutrino-process 11B and 7Li encapsulated in the grains. Combining the recent experimental constraints on θ13, we show that although the uncertainties are still large, our method hints at a marginal preference for an inverted neutrino mass hierarchy for the first time.

Relics in galaxy clusters at high radio frequencies

Science.gov (United States)

Kierdorf, M.; Beck, R.; Hoeft, M.; Klein, U.; van Weeren, R. J.; Forman, W. R.; Jones, C.

2017-04-01

Aims: We investigated the magnetic properties of radio relics located at the peripheries of galaxy clusters at high radio frequencies, where the emission is expected to be free of Faraday depolarization. The degree of polarization is a measure of the magnetic field compression and, hence, the Mach number. Polarization observations can also be used to confirm relic candidates. Methods: We observed three radio relics in galaxy clusters and one radio relic candidate at 4.85 and 8.35 GHz in total emission and linearly polarized emission with the Effelsberg 100-m telescope. In addition, we observed one radio relic candidate in X-rays with the Chandra telescope. We derived maps of polarization angle, polarization degree, and Faraday rotation measures. Results: The radio spectra of the integrated emission below 8.35 GHz can be well fitted by single power laws for all four relics. The flat spectra (spectral indices of 0.9 and 1.0) for the so-called Sausage relic in cluster CIZA J2242+53 and the so-called Toothbrush relic in cluster 1RXS 06+42 indicate that models describing the origin of relics have to include effects beyond the assumptions of diffuse shock acceleration. The spectra of the radio relics in ZwCl 0008+52 and in Abell 1612 are steep, as expected from weak shocks (Mach number ≈2.4). Polarization observations of radio relics offer a method of measuring the strength and geometry of the shock front. We find polarization degrees of more than 50% in the two prominent Mpc-sized radio relics, the Sausage and the Toothbrush, which are among the highest percentages of linear polarization detected in any extragalactic radio source to date. This is remarkable because the large beam size of the Effelsberg single-dish telescope corresponds to linear extensions of about 300 kpc at 8.35 GHz at the distances of the relics. The high degree of polarization indicates that the magnetic field vectors are almost perfectly aligned along the relic structure, as expected for shock

Signals of dark matter in a supersymmetric two dark matter model

International Nuclear Information System (INIS)

Fukuoka, Hiroki; Suematsu, Daijiro; Toma, Takashi

2011-01-01

Supersymmetric radiative neutrino mass models have often two dark matter candidates. One is the usual lightest neutralino with odd R parity and the other is a new neutral particle whose stability is guaranteed by a discrete symmetry that forbids tree-level neutrino Yukawa couplings. If their relic abundance is comparable, dark matter phenomenology can be largely different from the minimal supersymmetric standard model (MSSM). We study this in a supersymmetric radiative neutrino mass model with the conserved R parity and a Z 2 symmetry weakly broken by the anomaly effect. The second dark matter with odd parity of this new Z 2 is metastable and decays to the neutralino dark matter. Charged particles and photons associated to this decay can cause the deviation from the expected background of the cosmic rays. Direct search of the neutralino dark matter is also expected to show different features from the MSSM since the relic abundance is not composed of the neutralino dark matter only. We discuss the nature of dark matter in this model by analyzing these signals quantitatively

Can sterile neutrinos be ruled out as warm dark matter candidates?

CERN Document Server

Viel, M; Hähnelt, M G; Matarrese, S; Riotto, Antonio; Viel, Matteo; Lesgourgues, Julien; Haehnelt, Martin G.; Matarrese, Sabino; Riotto, Antonio

2006-01-01

We present constraints on the mass of Warm Dark Matter (WDM) particles from a combined analysis of the matter power spectrum inferred from the SDSS (Sloan Digital Sky Survey) Lyman-alpha flux power spectrum at 2.2 10 keV (2 sigma) if the WDM consists of sterile neutrinos and m_wdm > 2 keV (2 sigma) for early decoupled thermal relics. These results significantly improve our previous estimates based on high-resolution Lyman-alpha forest data at lower redshift. Our new limits are consistent with those of Seljak et al. (2006), albeit ~ 30 % smaller. If we combine this bound with the constraint derived from X-ray flux observations in the Coma cluster periphery (Boyarsky et al.), we find that the only allowed sterile neutrino mass is ~ 10 keV (in the standard production scenario with non-resonant neutrino oscillations). Adding constraints based on X-ray fluxes from the Andromeda galaxy or the Milky Way, we find that dark matter particles cannot be sterile neutrinos, unless the latter are produced by resonant oscill...

Relic gravitational waves and cosmology

International Nuclear Information System (INIS)

Grishchuk, Leonid P

2005-01-01

The paper begins with a brief recollection of interactions of the author with Ya B Zeldovich in the context of the study of relic gravitational waves. The principles and early results on the quantum-mechanical generation of cosmological perturbations are then summarized. The expected amplitudes of relic gravitational waves differ in various frequency windows, and therefore the techniques and prospects of their detection are distinct. One section of the paper describes the present state of efforts in direct detection of relic gravitational waves. Another section is devoted to indirect detection via the anisotropy and polarization measurements of the cosmic microwave background (CMB) radiation. It is emphasized throughout the paper that the inference about the existence and expected amount of relic gravitational waves is based on a solid theoretical foundation and the best available cosmological observations. It is also explained in great detail what went wrong with the so-called 'inflationary gravitational waves', whose amount is predicted by inflationary theorists to be negligibly small, thus depriving them of any observational significance. (reviews of topical problems)

Study of electroweak vacuum stability from extended Higgs portal of dark matter and neutrinos

Science.gov (United States)

Ghosh, Purusottam; Saha, Abhijit Kumar; Sil, Arunansu

2018-04-01

We investigate the electroweak vacuum stability in an extended version of the Standard Model that incorporates two additional singlet scalar fields and three right-handed neutrinos. One of these extra scalars plays the role of dark matter, while the other scalar not only helps make the electroweak vacuum stable but also opens up the low-mass window of the scalar singlet dark matter (<500 GeV ). We consider the effect of large neutrino Yukawa coupling on the running of Higgs quartic coupling. We have analyzed the constraints on the model and identified the range of parameter space that is consistent with the neutrino mass, appropriate relic density, and direct search limits from the latest XENON 1T preliminary result as well as realized the stability of the electroweak vacuum up to the Planck scale.

Neutrinos and Big Bang Nucleosynthesis

Directory of Open Access Journals (Sweden)

Gary Steigman

2012-01-01

Full Text Available According to the standard models of particle physics and cosmology, there should be a background of cosmic neutrinos in the present Universe, similar to the cosmic microwave photon background. The weakness of the weak interactions renders this neutrino background undetectable with current technology. The cosmic neutrino background can, however, be probed indirectly through its cosmological effects on big bang nucleosynthesis (BBN and the cosmic microwave background (CMB radiation. In this BBN review, focused on neutrinos and more generally on dark radiation, the BBN constraints on the number of “equivalent neutrinos” (dark radiation, on the baryon asymmetry (baryon density, and on a possible lepton asymmetry (neutrino degeneracy are reviewed and updated. The BBN constraints on dark radiation and on the baryon density following from considerations of the primordial abundances of deuterium and helium-4 are in excellent agreement with the complementary results from the CMB, providing a suggestive, but currently inconclusive, hint of the presence of dark radiation, and they constrain any lepton asymmetry. For all the cases considered here there is a “lithium problem”: the BBN-predicted lithium abundance exceeds the observationally inferred primordial value by a factor of ~3.

Inhomogeneous neutrino degeneracy and big bang nucleosynthesis

International Nuclear Information System (INIS)

Whitmire, Scott E.; Scherrer, Robert J.

2000-01-01

We examine big bang nucleosynthesis (BBN) in the case of inhomogeneous neutrino degeneracy, in the limit where the fluctuations are sufficiently small on large length scales that the present-day element abundances are homogeneous. We consider two representative cases: degeneracy of the electron neutrino alone and equal chemical potentials for all three neutrinos. We use a linear programming method to constrain an arbitrary distribution of the chemical potentials. For the current set of (highly restrictive) limits on the primordial element abundances, homogeneous neutrino degeneracy barely changes the allowed range of the baryon-to-photon ratio η. Inhomogeneous degeneracy allows for little change in the lower bound on η, but the upper bound in this case can be as large as η=1.1x10 -8 (only ν e degeneracy) or η=1.0x10 -9 (equal degeneracies for all three neutrinos). For the case of inhomogeneous neutrino degeneracy, we show that there is no BBN upper bound on the neutrino energy density, which is bounded in this case only by limits from structure formation and the cosmic microwave background. (c) 2000 The American Physical Society

Research on Splicing Method of Digital Relic Fragment Model

Science.gov (United States)

Yan, X.; Hu, Y.; Hou, M.

2018-04-01

In the course of archaeological excavation, a large number of pieces of cultural relics were unearthed, and the restoration of these fragments was done manually by traditional arts and crafts experts. In this process, cultural relics experts often try to splice the existing cultural relics, and then use adhesive to stick together the fragments of correct location, which will cause irreversible secondary damage to cultural relics. In order to minimize such damage, the surveyors combine 3D laser scanning with computer technology, and use the method of establishing digital cultural relics fragments model to make virtual splicing of cultural relics. The 3D software on the common market can basically achieve the model translation and rotation, using this two functions can be achieved manually splicing between models, mosaic records after the completion of the specific location of each piece of fragments, so as to effectively reduce the damage to the relics had tried splicing process.

Determination of absolute neutrino masses from Z-bursts

International Nuclear Information System (INIS)

Fodor, Z.

2001-05-01

Ultrahigh energy neutrinos (UHEν) scatter on cosmological relic neutrinos (Rν) producing Z bosons, which can decay hadronically producing protons (Z-burst). We compare the predicted proton spectrum with the observed ultrahigh energy cosmic ray (UHECR) spectrum and determine the mass of the heaviest Rν via a maximum likelihood analysis. Our mass prediction depends on the origin of the power-like part of the UHECR spectrum: m ν = 2.34 -0.84 +1.29 eV for Galactic halo and 0.26 -0.14 +0.20 eV for extragalactic (EG) origin. The second mass, with a lower bound of 0.06 eV on the 95% confidence level (CL), is compatible with a hierarchical ν mass scenario with the largest mass suggested by the atmospheric ν oscillation. The necessary UHEν flux is compatible with present upper limits and should be detected in the near future. (orig.)

Report of the Solar and Atmospheric Neutrino Working Group

International Nuclear Information System (INIS)

Back, H.; Bahcall, J.N.; Bernabeu, J.; Boulay, M.G.; Bowles, T.; Calaprice, F.; Champagne, A.; Freedman, S.; Gai, M.; Galbiati, C.; Gallagher, H.; Gonzalez-Garcia, C.; Hahn, R.L.; Heeger, K.M.; Hime, A.; Jung, C.K.; Klein, J.R.; Koike, M.; Lanou, R.; Learned, J.G.; Lesko, K.T.; Losecco, J.; Maltoni, M.; Mann, A.; McKinsey, D.; Palomares-Ruiz, S.; Pena-Garay, C.; Petcov, S.T.; Piepke, A.; Pitt, M.; Raghavan, R.; Robertson, R.G.H.; Scholberg, K.; Sobel, H.W.; Takeuchi, T.; Vogelaar, R.; Wolfenstein, L.

2004-01-01

magnetized detector with flavor and antiflavor sensitivity. Additional priorities are nuclear physics measurements which will reduce the uncertainties in the predictions of the Standard Solar Model, and similar supporting measurements for atmospheric neutrinos (cosmic ray fluxes, magnetic fields, etc.). We note as well that the detectors for both solar and atmospheric neutrino measurements can serve as multipurpose detectors, with capabilities of discovering dark matter, relic supernova neutrinos, proton decay, or as targets for long baseline accelerator neutrino experiments

Application of 3d Model of Cultural Relics in Virtual Restoration

Science.gov (United States)

Zhao, S.; Hou, M.; Hu, Y.; Zhao, Q.

2018-04-01

In the traditional cultural relics splicing process, in order to identify the correct spatial location of the cultural relics debris, experts need to manually splice the existing debris. The repeated contact between debris can easily cause secondary damage to the cultural relics. In this paper, the application process of 3D model of cultural relic in virtual restoration is put forward, and the relevant processes and ideas are verified with the example of Terracotta Warriors data. Through the combination of traditional cultural relics restoration methods and computer virtual reality technology, virtual restoration of high-precision 3D models of cultural relics can provide a scientific reference for virtual restoration, avoiding the secondary damage to the cultural relics caused by improper restoration. The efficiency and safety of the preservation and restoration of cultural relics have been improved.

APPLICATION OF 3D MODEL OF CULTURAL RELICS IN VIRTUAL RESTORATION

Directory of Open Access Journals (Sweden)

S. Zhao

2018-04-01

Full Text Available In the traditional cultural relics splicing process, in order to identify the correct spatial location of the cultural relics debris, experts need to manually splice the existing debris. The repeated contact between debris can easily cause secondary damage to the cultural relics. In this paper, the application process of 3D model of cultural relic in virtual restoration is put forward, and the relevant processes and ideas are verified with the example of Terracotta Warriors data. Through the combination of traditional cultural relics restoration methods and computer virtual reality technology, virtual restoration of high-precision 3D models of cultural relics can provide a scientific reference for virtual restoration, avoiding the secondary damage to the cultural relics caused by improper restoration. The efficiency and safety of the preservation and restoration of cultural relics have been improved.

Big bang nucleosynthesis with Gaussian inhomogeneous neutrino degeneracy

International Nuclear Information System (INIS)

Stirling, Spencer D.; Scherrer, Robert J.

2002-01-01

We consider the effect of inhomogeneous neutrino degeneracy on big bang nucleosynthesis for the case where the distribution of neutrino chemical potentials is given by a Gaussian. The chemical potential fluctuations are taken to be isocurvature, so that only inhomogeneities in the electron chemical potential are relevant. Then the final element abundances are a function only of the baryon-photon ratio η, the effective number of additional neutrinos ΔN ν , the mean electron neutrino degeneracy parameter ξ-bar, and the rms fluctuation of the degeneracy parameter, σ ξ . We find that for fixed η, ΔN ν , and ξ-bar, the abundances of 4 He, D, and 7 Li are, in general, increasing functions of σ ξ . Hence, the effect of adding a Gaussian distribution for the electron neutrino degeneracy parameter is to decrease the allowed range for η. We show that this result can be generalized to a wide variety of distributions for ξ

Non-thermal production of minimal dark matter via right-handed neutrino decay

International Nuclear Information System (INIS)

Aoki, Mayumi; Toma, Takashi; Vicente, Avelino

2015-01-01

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2) L quintuplet and a scalar SU(2) L septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermal equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations

Explosive nucleosynthesis in a neutrino-driven core collapse supernova

International Nuclear Information System (INIS)

Fujimoto, Shin-ichiro; Kotake, Kei; Hashimoto, Masa-aki; Ono, Masaomi; Ohnishi, Naofumi

2010-01-01

We investigate explosive nucleosynthesis in a delayed neutrino-driven, supernova explosion aided by standing accretion shock instability (SASI), based on two-dimensional hydrodynamic simulations of the explosion of a 15 M · star. We take into accounts neutrino heating and cooling as well as change in electron fraction due to weak interactions appropriately, in the two-dimensional simulations. We assume the isotropic emission of neutrinos from the neutrino spheres with given luminosities. and the Fermi-Dirac distribution of given temperatures. We find that the stalled shock revives due to the neutrino heating aided by SASI for cases with L νe ≥3.9x10 52 ergss -1 and the as-pherical shock passes through the outer layers of the star (≥10,000 km), with the explosion energies of ∼10 51 ergs.Next we examine abundances and masses of the supernova ejecta. We find that masses of the ejecta and 56 Ni correlate with the neutrino luminosity, and 56 Ni mass is comparable to that observed in SN 1987A. We also find that abundance pattern of the supernova ejecta is similar to that of the solar system, for cases with high explosion energies of >10 51 ergs. We emphasize that 64 Zn, which is underproduced in the spherical case, is abundantly produced in slightly neutron-rich ejecta.

Improved determination of sterile neutrino dark matter spectrum

International Nuclear Information System (INIS)

Ghiglieri, J.; Laine, M.

2015-01-01

The putative recent indication of an unidentified 3.55 keV X-ray line in certain astrophysical sources is taken as a motivation for an improved theoretical computation of the cosmological abundance of 7.1 keV sterile neutrinos. If the line is interpreted as resulting from the decay of Warm Dark Matter, the mass and mixing angle of the sterile neutrino are known. Our computation then permits for a determination of the lepton asymmetry that is needed for producing the correct abundance via the Shi-Fuller mechanism, as well as for an estimate of the non-equilibrium spectrum of the sterile neutrinos. The latter plays a role in structure formation simulations. Results are presented for different flavour structures of the neutrino Yukawa couplings and for different types of pre-existing lepton asymmetries, accounting properly for the charge neutrality of the plasma and incorporating approximately hadronic contributions.

Exploration and implementation of ontology-based cultural relic knowledge map integration platform

Science.gov (United States)

Yang, Weiqiang; Dong, Yiqiang

2018-05-01

To help designers to better carry out creative design and improve the ability of searching traditional cultural relic information, the ontology-based knowledge map construction method was explored and an integrated platform for cultural relic knowledge map was developed. First of all, the construction method of the ontology of cultural relics was put forward, and the construction of the knowledge map of cultural relics was completed based on the constructed cultural relic otology. Then, a personalized semantic retrieval framework for creative design was proposed. Finally, the integrated platform of the knowledge map of cultural relics was designed and realized. The platform was divided into two parts. One was the foreground display system, which was used for designers to search and browse cultural relics. The other was the background management system, which was for cultural experts to manage cultural relics' knowledge. The research results showed that the platform designed could improve the retrieval ability of cultural relic information. To sum up, the platform can provide a good support for the designer's creative design.

Stau relic density at the big-bang nucleosynthesis era in the coannihilation scenario and a solution to the Li7 problem

Science.gov (United States)

Jittoh, Toshifumi; Kohri, Kazunori; Koike, Masafumi; Sato, Joe; Shimomura, Takashi; Yamanaka, Masato

2010-12-01

We calculate the relic density of stau at the big-bang nucleosynthesis era in the coannihilation scenario of the minimal supersymmetric standard model. In this scenario, stau can be long lived and have significance in the remediation of light elements abundances. The freeze-out of stau is corroborated by solving the Boltzmann equation numerically, and the parameter dependence of the relic density is investigated. The possibility of solving the Li7 problem is examined by taking account into the long-lived stau. By adopting an observational value of Li7 in [J. Meléndez and I. Ramírez, Astrophys. J. 615, L33 (2004).ASJOAB0004-637X10.1086/425962], we get minimal supersymmetric standard model parameter space in which abundances of both dark matter and all of the light elements are reproduced in accordance with observations. We also address the influence of intergenerational mixing on our calculation.

Non-thermal production of minimal dark matter via right-handed neutrino decay

Energy Technology Data Exchange (ETDEWEB)

Aoki, Mayumi [Institute for Theoretical Physics, Kanazawa University,Kanazawa 920-1192 (Japan); Toma, Takashi [Laboratoire de Physique Théorique, CNRS - UMR 8627, Université de Paris-Sud 11,F-91405 Orsay Cedex (France); Vicente, Avelino [IFPA, Dep. AGO, Université de Liège,Bat B5, Sart-Tilman B-4000 Liège 1 (Belgium); Instituto de Física Corpuscular, CSIC-Universitat de València,Apdo. 22085, E-46071 Valencia (Spain)

2015-09-29

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2){sub L} quintuplet and a scalar SU(2){sub L} septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermal equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations.

Non-thermal production of minimal dark matter via right-handed neutrino decay

Energy Technology Data Exchange (ETDEWEB)

Aoki, Mayumi [Institute for Theoretical Physics, Kanazawa University, Kanazawa 920-1192 (Japan); Toma, Takashi [Laboratoire de Physique Théorique, CNRS - UMR 8627, Université de Paris-Sud 11, F-91405 Orsay Cedex (France); Vicente, Avelino, E-mail: mayumi@hep.s.kanazawa-u.ac.jp, E-mail: takashi.toma@th.u-psud.fr, E-mail: Avelino.Vicente@ulg.ac.be [IFPA, Dep. AGO, Université de Liège, Bat B5, Sart-Tilman B-4000 Liège 1 (Belgium)

2015-09-01

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2){sub L} quintuplet and a scalar SU(2){sub L} septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermal equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations.

SCRMS: An RFID and Sensor Web-Enabled Smart Cultural Relics Management System.

Science.gov (United States)

Xiao, Changjiang; Chen, Nengcheng; Li, Dandan; Lv, You; Gong, Jianya

2016-12-30

Cultural relics represent national or even global resources of inestimable value. How to efficiently manage and preserve these cultural relics is a vitally important issue. To achieve this goal, this study proposed, designed, and implemented an RFID and Sensor Web-enabled smart cultural relics management system (SCRMS). In this system, active photovoltaic subtle energy-powered Radio Frequency Identification (RFID) is used for long-range contactless identification and lifecycle management of cultural relics during their storage and circulation. In addition, different types of ambient sensors are integrated with the RFID tags and deployed around cultural relics to monitor their environmental parameters, helping to ensure that they remain in good condition. An Android-based smart mobile application, as middleware, is used in collaboration with RFID readers to collect information and provide convenient management for the circulation of cultural relics. Moreover, multiple sensing techniques are taken advantage of simultaneously for preservation of cultural relics. The proposed system was successfully applied to a museum in the Yongding District, Fujian Province, China, demonstrating its feasibility and advantages for smart and efficient management and preservation of cultural relics.

Stochastic backgrounds of relic gravitons: a theoretical appraisal

CERN Document Server

Giovannini, Massimo

2010-01-01

Stochastic backgrounds or relic gravitons, if ever detected, will constitute a prima facie evidence of physical processes taking place during the earliest stages of the evolution of the plasma. The essentials of the stochastic backgrounds of relic gravitons are hereby introduced and reviewed. The pivotal observables customarily employed to infer the properties of the relic gravitons are discussed both in the framework of the $\\Lambda$CDM paradigm as well as in neighboring contexts. The complementarity between experiments measuring the polarization of the Cosmic Microwave Background (such as, for instance, WMAP, Capmap, Quad, Cbi, just to mention a few) and wide band interferometers (e.g. Virgo, Ligo, Geo, Tama) is emphasized. While the analysis of the microwave sky strongly constrains the low-frequency tail of the relic graviton spectrum, wide-band detectors are sensitive to much higher frequencies where the spectral energy density depends chiefly upon the (poorly known) rate of post-inflationary expansion.

Neutrino Emission from Supernovae

Science.gov (United States)

Janka, Hans-Thomas

Supernovae are the most powerful cosmic sources of MeV neutrinos. These elementary particles play a crucial role when the evolution of a massive star is terminated by the collapse of its core to a neutron star or a black hole and the star explodes as supernova. The release of electron neutrinos, which are abundantly produced by electron captures, accelerates the catastrophic infall and causes a gradual neutronization of the stellar plasma by converting protons to neutrons as dominant constituents of neutron star matter. The emission of neutrinos and antineutrinos of all flavors carries away the gravitational binding energy of the compact remnant and drives its evolution from the hot initial to the cold final state. The absorption of electron neutrinos and antineutrinos in the surroundings of the newly formed neutron star can power the supernova explosion and determines the conditions in the innermost supernova ejecta, making them an interesting site for the nucleosynthesis of iron-group elements and trans-iron nuclei.

GALAXY CLUSTER RADIO RELICS IN ADAPTIVE MESH REFINEMENT COSMOLOGICAL SIMULATIONS: RELIC PROPERTIES AND SCALING RELATIONSHIPS

International Nuclear Information System (INIS)

Skillman, Samuel W.; Hallman, Eric J.; Burns, Jack O.; Smith, Britton D.; O'Shea, Brian W.; Turk, Matthew J.

2011-01-01

Cosmological shocks are a critical part of large-scale structure formation, and are responsible for heating the intracluster medium in galaxy clusters. In addition, they are capable of accelerating non-thermal electrons and protons. In this work, we focus on the acceleration of electrons at shock fronts, which is thought to be responsible for radio relics-extended radio features in the vicinity of merging galaxy clusters. By combining high-resolution adaptive mesh refinement/N-body cosmological simulations with an accurate shock-finding algorithm and a model for electron acceleration, we calculate the expected synchrotron emission resulting from cosmological structure formation. We produce synthetic radio maps of a large sample of galaxy clusters and present luminosity functions and scaling relationships. With upcoming long-wavelength radio telescopes, we expect to see an abundance of radio emission associated with merger shocks in the intracluster medium. By producing observationally motivated statistics, we provide predictions that can be compared with observations to further improve our understanding of magnetic fields and electron shock acceleration.

Nuclear weak interactions, supernova nucleosynthesis and neutrino oscillation

Science.gov (United States)

Kajino, Toshitaka

2013-07-01

We study the nuclear weak response in light-to-heavy mass nuclei and calculate neutrino-nucleus cross sections. We apply these cross sections to the explosive nucleosynthesis in core-collapse supernovae and find that several isotopes of rare elements 7Li, 11B, 138La, 180Ta and several others are predominantly produced by the neutrino-process nucleosynthesis. We discuss how to determine the suitable neutrino spectra of three different flavors and their anti-particles in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. Light-mass nuclei like 7Li and 11B, which are produced in outer He-layer, are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect, while heavy-mass nuclei like 138La, 180Ta and r-process elements, which are produced in the inner O-Ne-Mg layer or the atmosphere of proto-neutron star, are likely to be free from the MSW effect. Using such a different nature of the neutrino-process nucleosynthesis, we study the neutrino oscillation effects on their abundances, and propose a new novel method to determine the unknown neutrino oscillation parameters, θ13 and mass hierarchy, simultaneously. There is recent evidence that some SiC X grains from the Murchison meteorite may contain supernova-produced neutrino-process 11B and 7Li encapsulated in the grains. Combining the recent experimental constraints on θ13, we show that although the uncertainties are still large, our method hints at a marginal preference for an inverted neutrino mass hierarchy for the first time.

SCRMS: An RFID and Sensor Web-Enabled Smart Cultural Relics Management System

Directory of Open Access Journals (Sweden)

Changjiang Xiao

2016-12-01

Full Text Available Cultural relics represent national or even global resources of inestimable value. How to efficiently manage and preserve these cultural relics is a vitally important issue. To achieve this goal, this study proposed, designed, and implemented an RFID and Sensor Web–enabled smart cultural relics management system (SCRMS. In this system, active photovoltaic subtle energy-powered Radio Frequency Identification (RFID is used for long-range contactless identification and lifecycle management of cultural relics during their storage and circulation. In addition, different types of ambient sensors are integrated with the RFID tags and deployed around cultural relics to monitor their environmental parameters, helping to ensure that they remain in good condition. An Android-based smart mobile application, as middleware, is used in collaboration with RFID readers to collect information and provide convenient management for the circulation of cultural relics. Moreover, multiple sensing techniques are taken advantage of simultaneously for preservation of cultural relics. The proposed system was successfully applied to a museum in the Yongding District, Fujian Province, China, demonstrating its feasibility and advantages for smart and efficient management and preservation of cultural relics.

Twin radio relics in the nearby low-mass galaxy cluster Abell 168

Science.gov (United States)

Dwarakanath, K. S.; Parekh, V.; Kale, R.; George, L. T.

2018-06-01

We report the discovery of twin radio relics in the outskirts of the low-mass merging galaxy cluster Abell 168 (redshift=0.045). One of the relics is elongated with a linear extent ˜800 kpc and projected width of ˜80 kpc and is located ˜900 kpc towards the north of the cluster centre, oriented roughly perpendicular to the major axis of the X-ray emission. The second relic is ring-shaped with a size ˜220 kpc and is located near the inner edge of the elongated relic at a distance of ˜600 kpc from the cluster centre. These radio sources were imaged at 323 and 608 MHz with the Giant Meterwave Radio Telescope and at 1520 MHz with the Karl G. Jansky Very Large Array (VLA). The elongated relic was detected at all frequencies, with a radio power of 1.38 ± 0.14 × 1023 W Hz-1 at 1.4 GHz and a power law in the frequency range 70-1500 MHz (S ∝ να, α = -1.1 ± 0.04). This radio power is in good agreement with that expected from the known empirical relation between the radio powers of relics and host cluster masses. This is the lowest mass (M500 = 1.24 × 1014 M⊙) cluster in which relics due to merger shocks are detected. The ring-shaped relic has a steeper spectral index (α) of -1.74 ± 0.29 in the frequency range 100-600 MHz. We propose this relic to be an old plasma, revived due to adiabatic compression by the outgoing shock that produced the elongated relic.

Unified scenario for composite right-handed neutrinos and dark matter

Science.gov (United States)

Davoudiasl, Hooman; Giardino, Pier Paolo; Neil, Ethan T.; Rinaldi, Enrico

2017-12-01

We entertain the possibility that neutrino masses and dark matter (DM) originate from a common composite dark sector. A minimal effective theory can be constructed based on a dark S U (3 )D interaction with three flavors of massless dark quarks; electroweak symmetry breaking gives masses to the dark quarks. By assigning a Z2 charge to one flavor, a stable "dark kaon" can provide a good thermal relic DM candidate. We find that "dark neutrons" may be identified as right handed Dirac neutrinos. Some level of "neutron-anti-neutron" oscillation in the dark sector can then result in non-zero Majorana masses for light standard model neutrinos. A simple ultraviolet completion is presented, involving additional heavy S U (3 )D-charged particles with electroweak and lepton Yukawa couplings. At our benchmark point, there are "dark pions" that are much lighter than the Higgs and we expect spectacular collider signals arising from the UV framework. This includes the decay of the Higgs boson to τ τ ℓℓ', where ℓ(ℓ') can be any lepton, with displaced vertices. We discuss the observational signatures of this UV framework in dark matter searches and primordial gravitational wave experiments; the latter signature is potentially correlated with the H →τ τ ℓℓ' decay.

Light sterile neutrino sensitivity at the nuSTORM facility

CERN Document Server

Adey, D; Ankenbrandt, C.M.; Asfandiyarov, R.; Back, J.J.; Barker, G.; Baussan, E.; Bayes, R.; Bhadra, S.; Blackmore, V.; Blondel, A.; Bogacz, S.A.; Booth, C.; Boyd, S.B.; Bramsiepe, S.G.; Bravar, A.; Brice, S.J.; Bross, A.D.; Cadoux, F.; Cease, H.; Cervera, A.; Cobb, J.; Colling, D.; Coloma, P.; Coney, L.; Dobbs, A.; Dobson, J.; Donini, A.; Dornan, P.; Dracos, M.; Dufour, F.; Edgecock, R.; Geelhoed, M.; Uchida, M.A.; Ghosh, T.; Gomez-Cadenas, J.J.; de Gouvea, A.; Haesler, A.; Hanson, G.; Harrison, P.F.; Hartz, M.; Hernandez, P.; Hernando Morata, J.A.; Hodgson, P.; Huber, P.; Izmaylov, A.; Karadzhov, Y.; Kobilarcik, T.; Kopp, J.; Kormos, L.; Korzenev, A.; Kuno, Y.; Kurup, A.; Kyberd, P.; Lagrange, J.B.; Laing, A.; Liu, A.; Link, J.M.; Long, K.; Mahn, K.; Mariani, C.; Martin, C.; Martin, J.; McCauley, N.; McDonald, K.T.; Mena, O.; Mishra, S.R.; Mokhov, N.; Morfin, J.; Mori, Y.; Murray, W.; Neuffer, D.; Nichol, R.; Noah, E.; Palmer, M.A.; Parke, S.; Pascoli, S.; Pasternak, J.; Plunkett, R.; Popovic, M.; Ratoff, P.; Ravonel, M.; Rayner, M.; Ricciardi, S.; Rogers, C.; Rubinov, P.; Santos, E.; Sato, A.; Sen, T.; Scantamburlo, E.; Sedgbeer, J.K.; Smith, D.R.; Smith, P.J.; Sobczyk, J.T.; Sby, L.; Soler, F.J.P.; Sorel, M.; Snopok, P.; Stamoulis, P.; Stanco, L.; Striganov, S.; Tanaka, H.A.; Taylor, I.J.; Touramanis, C.; Tunnell, C.D.; Uchida, Y.; Vassilopoulos, N.; Wascko, M.O.; Weber, A.; Wilking, M.J.; Wildner, E.; Winter, W.

2014-01-01

A facility that can deliver beams of electron and muon neutrinos from the decay of a stored muon beam has the potential to unambiguously resolve the issue of the evidence for light sterile neutrinos that arises in short-baseline neutrino oscillation experiments and from estimates of the effective number of neutrino flavors from fits to cosmological data. In this paper, we show that the nuSTORM facility, with stored muons of 3.8 GeV/c $\\pm$ 10%, will be able to carry out a conclusive muon neutrino appearance search for sterile neutrinos and test the LSND and MiniBooNE experimental signals with 10$\\sigma$ sensitivity, even assuming conservative estimates for the systematic uncertainties. This experiment would add greatly to our knowledge of the contribution of light sterile neutrinos to the number of effective neutrino flavors from the abundance of primordial helium production and from constraints on neutrino energy density from the cosmic microwave background. The appearance search is complemented by a simulta...

Freeze-in production of sterile neutrino dark matter in U(1){sub B−L} model

Energy Technology Data Exchange (ETDEWEB)

Biswas, Anirban; Gupta, Aritra [Harish-Chandra Research Institute,Chhatnag Road, Jhunsi, Allahabad 211 019 (India)

2016-09-27

With the advent of new and more sensitive direct detection experiments, scope for a thermal WIMP explanation of dark matter (DM) has become extremely constricted. The non-observation of thermal WIMP in these experiments has put a strong upper bound on WIMP-nucleon scattering cross section and within a few years it is likely to overlap with the coherent neutrino-nucleon cross section. Hence in all probability, DM may have some non-thermal origin. In this work we explore in detail this possibility of a non-thermal sterile neutrino DM within the framework of U(1){sub B−L} model. The U(1){sub B−L} model on the other hand is a well-motivated and minimal way of extending the standard model so that it can explain the neutrino masses via Type-I see-saw mechanism. We have shown, besides explaining the neutrino mass, it can also accommodate a non-thermal sterile neutrino DM with correct relic density. In contrast with the existing literature, we have found that W{sup ±} decay can also be a dominant production mode of the sterile neutrino DM. To obtain the comoving number density of dark matter, we have solved here a coupled set of Boltzmann equations considering all possible decay as well as annihilation production modes of the sterile neutrino dark matter. The framework developed here though has been done for a U(1){sub B−L} model, can be applied quite generally for any models with an extra neutral gauge boson and a fermionic non-thermal dark matter.

Neutrino nucleosynthesis in supernovae: Shell model predictions

International Nuclear Information System (INIS)

Haxton, W.C.

1989-01-01

Almost all of the 3 · 10 53 ergs liberated in a core collapse supernova is radiated as neutrinos by the cooling neutron star. I will argue that these neutrinos interact with nuclei in the ejected shells of the supernovae to produce new elements. It appears that this nucleosynthesis mechanism is responsible for the galactic abundances of 7 Li, 11 B, 19 F, 138 La, and 180 Ta, and contributes significantly to the abundances of about 15 other light nuclei. I discuss shell model predictions for the charged and neutral current allowed and first-forbidden responses of the parent nuclei, as well as the spallation processes that produce the new elements. 18 refs., 1 fig., 1 tab

Round table discussion of future Solar Neutrino Program

International Nuclear Information System (INIS)

Anon.

1978-01-01

The discussion of the future neutrino program includes a critique of the chlorine-37 experiment and the necessary continued effort, the astronomical and cosmological implications of the various nonstandard models, future programs in laboratory experiments and theoretical calculations on reaction cross sections, opacities, convections, and observations of elemental abundances on the Sun and the meteorites, and lastly the program in solar neutrino research

Sterile neutrinos in light of recent cosmological and oscillation data: a multi-flavor scheme approach

International Nuclear Information System (INIS)

Melchiorri, Alessandro; Mena, Olga; Sorel, Michel; Palomares-Ruiz, Sergio; Pascoli, Silvia; Slosar, Anze

2009-01-01

Light sterile neutrinos might mix with the active ones and be copiously produced in the early Universe. In the present paper, a detailed multi-flavor analysis of sterile neutrino production is performed. Making some justified approximations allows us to consider not only neutrino interactions with the primeval medium and neutrino coherence breaking effects, but also oscillation effects arising from the presence of three light (mostly-active) neutrino states mixed with two heavier (mostly-sterile) states. First, we emphasize the underlying physics via an analytical description of sterile neutrino abundances that is valid for cases with small mixing between active and sterile neutrinos. Then, we study in detail the phenomenology of (3+2) sterile neutrino models in light of short-baseline oscillation data, including the LSND and MiniBooNE results. Finally, by using the information provided by this analysis, we obtain the expected sterile neutrino cosmological abundances and then contrast them with the most recent available data from Cosmic Microwave Background and Large Scale Structure observations. We conclude that (3+2) models are significantly more disfavored by the internal inconsistencies between sterile neutrino interpretations of appearance and disappearance short-baseline data themselves, rather than by the used cosmological data

Lepton asymmetry, neutrino spectral distortions, and big bang nucleosynthesis

Science.gov (United States)

Grohs, E.; Fuller, George M.; Kishimoto, C. T.; Paris, Mark W.

2017-03-01

We calculate Boltzmann neutrino energy transport with self-consistently coupled nuclear reactions through the weak-decoupling-nucleosynthesis epoch in an early universe with significant lepton numbers. We find that the presence of lepton asymmetry enhances processes which give rise to nonthermal neutrino spectral distortions. Our results reveal how asymmetries in energy and entropy density uniquely evolve for different transport processes and neutrino flavors. The enhanced distortions in the neutrino spectra alter the expected big bang nucleosynthesis light element abundance yields relative to those in the standard Fermi-Dirac neutrino distribution cases. These yields, sensitive to the shapes of the neutrino energy spectra, are also sensitive to the phasing of the growth of distortions and entropy flow with time/scale factor. We analyze these issues and speculate on new sensitivity limits of deuterium and helium to lepton number.

Dark matter and neutrino mass from the smallest non-Abelian chiral dark sector

Science.gov (United States)

Berryman, Jeffrey M.; de Gouvêa, André; Kelly, Kevin J.; Zhang, Yue

2017-10-01

All pieces of concrete evidence for phenomena outside the standard model (SM)—neutrino masses and dark matter—are consistent with the existence of new degrees of freedom that interact very weakly, if at all, with those in the SM. We propose that these new degrees of freedom organize themselves into a simple dark sector, a chiral S U (3 )×S U (2 ) gauge theory with the smallest nontrivial fermion content. Similar to the SM, the dark S U (2 ) is spontaneously broken while the dark S U (3 ) confines at low energies. At the renormalizable level, the dark sector contains massless fermions—dark leptons—and stable massive particles—dark protons. We find that dark protons with masses between 10 and 100 TeV satisfy all current cosmological and astrophysical observations concerning dark matter even if dark protons are a symmetric thermal relic. The dark leptons play the role of right-handed neutrinos and allow simple realizations of the seesaw mechanism or the possibility that neutrinos are Dirac fermions. In the latter case, neutrino masses are also parametrically different from charged-fermion masses and the lightest neutrino is predicted to be massless. Since the new "neutrino" and "dark-matter" degrees of freedom interact with one another, these two new-physics phenomena are intertwined. Dark leptons play a nontrivial role in early Universe cosmology while indirect searches for dark matter involve, decisively, dark-matter annihilations into dark leptons. These, in turn, may lead to observable signatures at high-energy neutrino and gamma-ray observatories, especially once one accounts for the potential Sommerfeld enhancement of the annihilation cross section, derived from the low-energy dark-sector effective theory, a possibility we explore quantitatively in some detail.

Boltzmann hierarchy for interacting neutrinos I: formalism

International Nuclear Information System (INIS)

Oldengott, Isabel M.; Rampf, Cornelius; Wong, Yvonne Y.Y.

2015-01-01

Starting from the collisional Boltzmann equation, we derive for the first time and from first principles the Boltzmann hierarchy for neutrinos including interactions with a scalar particle. Such interactions appear, for example, in majoron-like models of neutrino mass generation. We study two limits of the scalar mass: (i) An extremely massive scalar whose only role is to mediate an effective 4-fermion neutrino-neutrino interaction, and (ii) a massless scalar that can be produced in abundance and thus demands its own Boltzmann hierarchy. In contrast to, e.g., the first-order Boltzmann hierarchy for Thomson-scattering photons, our interacting neutrino/scalar Boltzmann hierarchies contain additional momentum-dependent collision terms arising from a non-negligible energy transfer in the neutrino-neutrino and neutrino-scalar interactions. This necessitates that we track each momentum mode of the phase space distributions individually, even if the particles were massless. Comparing our hierarchy with the commonly used (c eff 2 ,c vis 2 )-parameterisation, we find no formal correspondence between the two approaches, which raises the question of whether the latter parameterisation even has an interpretation in terms of particle scattering. Lastly, although we have invoked majoron-like models as a motivation for our study, our treatment is in fact generally applicable to all scenarios in which the neutrino and/or other ultrarelativistic fermions interact with scalar particles

Supernova neutrinos, giant resonances, and nucleosynthesis

International Nuclear Information System (INIS)

Haxton, W.

1990-01-01

Almost all of the 3·10 53 ergs liberated in a core collapse supernova is radiated as neutrinos by the cooling neutron star. The neutrinos can excite nuclei in the mantle of the star by their neutral and charged current reactions. I argue that the resulting spallation reactions are an important nucleosynthesis mechanism that may be responsible for the galactic abundances of 7 Li, 11 B, 19 F, 138 La, 180 Ta, and approximately a dozen other light nuclei. 18 refs., 1 fig., 1 tab

Massive neutrinos and cosmology

International Nuclear Information System (INIS)

Shandarin, S.F.

1991-01-01

This paper discussed the importance of the consequences of a nonzero neutrino rest mass on cosmology, perhaps, first recognized by Gershtein and Zeldovich, after the discover of the 3-K microwave background radiation MBR. Since the first works on the primordial synthesis of 4 He, it has been known that additional neutrino species increase the rate of expansion of the universe during the epoch of the primordial nucleosynthesis, which increases the yield of 4 He. Combining the results of the theory with astronomical measurements of the 4 He abundance and the estimate of the mass density of MBR, Shvartsman suggested the upper limit on the mass density of all relativistic matter at that epoch: ρ rel ≤ 5ρ MBR which eventually became the upper limit for the number of neutrino species: N ν ≤ 7. At that time, the constraints based on cosmological arguments were much stronger than one based on laboratory experiments

A Zoo of Radio Relics: Cluster Cores to Filaments Ruta Kale1,2 ...

Indian Academy of Sciences (India)

Abstract. Radio relics in galaxy clusters can be electrons accelerated at cluster merger shocks or adiabatically compressed fossil radio cocoons or dying radio galaxies. The spectral evolution of radio relics is affected by the surrounding thermal plasma. We present a low frequency study of three radio relics representing ...

Unifying leptogenesis, dark matter and high-energy neutrinos with right-handed neutrino mixing via Higgs portal

Energy Technology Data Exchange (ETDEWEB)

Bari, Pasquale Di; Ludl, Patrick Otto [Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Palomares-Ruiz, Sergio [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València,Apartado de Correos 22085, E-46071 Valencia (Spain)

2016-11-21

We revisit a model in which neutrino masses and mixing are described by a two right-handed (RH) neutrino seesaw scenario, implying a strictly hierarchical light neutrino spectrum. A third decoupled RH neutrino, N{sub DM} with mass M{sub DM}, plays the role of cold dark matter (DM) and is produced by the mixing with a source RH neutrino, N{sub S} with mass M{sub S}, induced by Higgs portal interactions. The same interactions are also responsible for N{sub DM} decays. We discuss in detail the constraints coming from DM abundance and stability conditions showing that in the hierarchical case, for M{sub DM}≫M{sub S}, there is an allowed window on M{sub DM} values necessarily implying a contribution, from DM decays, to the high-energy neutrino flux recently detected by IceCube. We also show how the model can explain the matter-antimatter asymmetry of the Universe via leptogenesis in the quasi-degenerate limit. In this case, the DM mass should be within the range 300 GeV ≲M{sub S}neutrino flux and show the predicted event spectrum for two exemplary cases. Although DM decays, with a relatively hard spectrum, cannot account for all the IceCube high-energy data, we illustrate how this extra source of high-energy neutrinos could reasonably explain some potential features in the observed spectrum. In this way, this represents a unified scenario for leptogenesis and DM that could be tested during the next years with more high-energy neutrino events.

Mixed Inert scalar triplet dark matter, radiative neutrino masses and leptogenesis

Directory of Open Access Journals (Sweden)

Wen-Bin Lu

2017-11-01

Full Text Available The neutral component of an inert scalar multiplet with hypercharge can provide a stable dark matter particle when its real and imaginary parts have a splitting mass spectrum. Otherwise, a tree-level dark-matter-nucleon scattering mediated by the Z boson will be much above the experimental limit. In this paper we focus on a mixed inert scalar triplet dark matter scenario where a complex scalar triplet with hypercharge can mix with another real scalar triplet without hypercharge through their renormalizable coupling to the standard model Higgs doublet. We consider three specified cases that carry most of the relevant features of the full parameter space: (i the neutral component of the real triplet dominates the dark matter particle, (ii the neutral component of the complex triplet dominates the dark matter particle; and (iii the neutral components of the real and complex triplets equally constitute the dark matter particle. Subject to the dark matter relic abundance and direct detection constraint, we perform a systematic study on the allowed parameter space with particular emphasis on the interplay among triplet-doublet terms and gauge interactions. In the presence of these mixed inert scalar triplets, some heavy Dirac fermions composed of inert fermion doublets can be utilized to generate a tiny Majorana neutrino mass term at one-loop level and realize a successful leptogenesis for explaining the cosmic baryon asymmetry.

Unveiling secret interactions among sterile neutrinos with big-bang nucleosynthesis

Science.gov (United States)

Saviano, Ninetta; Pisanti, Ofelia; Mangano, Gianpiero; Mirizzi, Alessandro

2014-12-01

Short-baseline neutrino anomalies suggest the existence of low-mass [m ˜O (1 ) eV ] sterile neutrinos νs. These would be efficiently produced in the early universe by oscillations with active neutrino species, leading to a thermal population of the sterile states seemingly incompatible with cosmological observations. In order to relieve this tension it has been recently speculated that new "secret" interactions among sterile neutrinos, mediated by a massive gauge boson X (with MX≪MW), can inhibit or suppress the sterile neutrino thermalization, due to the production of a large matter potential term. We note however, that they also generate strong collisional terms in the sterile neutrino sector that induce an efficient sterile neutrino production after a resonance in matter is encountered, increasing their contribution to the number of relativistic particle species Neff. Moreover, for values of the parameters of the νs-νs interaction for which the resonance takes place at temperature T ≲few MeV , significant distortions are produced in the electron (anti)neutrino spectra, altering the abundance of light element in big bang nucleosynthesis (BBN). Using the present determination of 4He and deuterium primordial abundances we determine the BBN constraints on the model parameters. We find that 2H/H density ratio exclude much of the parameter space if one assumes a baryon density at the best fit value of Planck experiment, ΩBh2=0.02207 , while bounds become weaker for a higher ΩBh2=0.02261 , the 95% C.L. upper bound of Planck. Due to the large error on its experimental determination, the helium mass fraction Yp gives no significant bounds.

Dilaton could affect abundance of dark matter particles

CERN Multimedia

2007-01-01

"The amount of dark matter left over from the early universe may be less than previously believed. new research shows that the "relic abundance" of stable dark matter particles such as the neutralino may be reduced as compared to standard cosmology theories due to the effects of the "dilaton", a particle with zero spin in the gravitational sector of strings." (1 page)

Neutrino-induced nucleosynthesis in core-collapse supernovae

International Nuclear Information System (INIS)

Hartmann, D.H.; Haxton, W.C.; Hoffman, R.D.; Woosley, S.E.; California Univ., Santa Cruz, CA

1990-01-01

Almost all of the 3·10 53 ergs liberated in a core collapse supernova is radiated as neutrinos by the cooling neutron star. The neutrinos can excite nuclei in the mantle of the star by their neutral and charged current reactions. The resulting spallation reactions are an important nuleosynthesis mechanism that may be responsible for the galactic abundances of 7 Li, 11 B, 19 F, 138 La, 180 Ta, and number of other nuclei. 10 refs., 1 fig., 1 tab

First Anti-neutrino Oscillation Results from the T2K Experiment

CERN Multimedia

CERN. Geneva

2015-01-01

Neutrinos are some of the most abundant but yet most elusive particles in the universe. They have almost no mass, only interact weakly and relatively little is known about their properties. Furthermore it has been firmly established over the last decade that neutrinos can undergo flavour transitions as mass and flavor eigenstates are not identical. These neutrino oscillations have been studied using natural sources as well as nuclear reactors or with neutrinos produced at accelerators. T2K is a long baseline neutrino oscillation beam that uses a beam of muon (anti-)neutrinos that is directed form J-PARC at the east cost of Japan over a distance of almost 300 km to the SuperKamiokande water Cherenkov detector in the west. The facility is complemented by a near detector complex 280 m downstream of the neutrino production target to characterise the beam and the neutrino interaction dynamics. T2K has taken data with a muon neutrino beam since early 2010 and is studying the disappearance of muon neutrinos as well...

Neutrino masses, leptogenesis and dark matter from small lepton number violation?

Energy Technology Data Exchange (ETDEWEB)

Abada, Asmaa [CNRS, Univ. Paris-Sud, Univ. Paris-Saclay, Orsay (France). Lab. de Physique Theorique; Arcadi, Giorgio [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Domcke, Valerie [Paris Diderot Univ. (France). AstroParticule et Cosmologie (APC)/Paris Centre for Cosmological Physics (PCCP); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Lucente, Michele [Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium). Centre for Cosmology, Particle Physics and Phenomenology (CP3)

2017-09-05

We consider the possibility of simultaneously addressing the baryon asymmetry of the Universe, the dark matter problem and the neutrino mass generation in minimal extensions of the Standard Model via sterile fermions with (small) total lepton number violation. Within the framework of Inverse and Linear Seesaw models, the small lepton number violating parameters set the mass scale of the active neutrinos, the efficiency of leptogenesis through a small mass splitting between pairs of sterile fermions as well as the mass scale of a sterile neutrino dark matter candidate. We provide an improved parametrization of these seesaw models taking into account existing experimental constraints and derive a linearized system of Boltzmann equations to describe the leptogenesis process, which allows for an efficient investigation of the parameter space. This in particular enables us to perform a systematic study of the strong washout regime of leptogenesis. Our study reveals that one can have a successful leptogenesis at the temperature of the electroweak scale through oscillations between two sterile states with a natural origin of the (necessary) strong degeneracy in their mass spectrum. The minimal model however requires a non-standard cosmological history to account for the relic dark matter. Finally, we discuss the prospect for neutrinoless double beta decay and for testing, in future experiments, the values of mass and different active-sterile mixings required for successful leptogenesis.

Neutrino masses, leptogenesis and dark matter from small lepton number violation?

Science.gov (United States)

Abada, Asmaa; Arcadi, Giorgio; Domcke, Valerie; Lucente, Michele

2017-12-01

We consider the possibility of simultaneously addressing the baryon asymmetry of the Universe, the dark matter problem and the neutrino mass generation in minimal extensions of the Standard Model via sterile fermions with (small) total lepton number violation. Within the framework of Inverse and Linear Seesaw models, the small lepton number violating parameters set the mass scale of the active neutrinos, the efficiency of leptogenesis through a small mass splitting between pairs of sterile fermions as well as the mass scale of a sterile neutrino dark matter candidate. We provide an improved parametrization of these seesaw models taking into account existing experimental constraints and derive a linearized system of Boltzmann equations to describe the leptogenesis process, which allows for an efficient investigation of the parameter space. This in particular enables us to perform a systematic study of the strong washout regime of leptogenesis. Our study reveals that one can have a successful leptogenesis at the temperature of the electroweak scale through oscillations between two sterile states with a natural origin of the (necessary) strong degeneracy in their mass spectrum. The minimal model however requires a non-standard cosmological history to account for the relic dark matter. Finally, we discuss the prospect for neutrinoless double beta decay and for testing, in future experiments, the values of mass and different active-sterile mixings required for successful leptogenesis.

Neutrino masses, leptogenesis and dark matter from small lepton number violation?

International Nuclear Information System (INIS)

Abada, Asmaa; Domcke, Valerie; Lucente, Michele

2017-01-01

We consider the possibility of simultaneously addressing the baryon asymmetry of the Universe, the dark matter problem and the neutrino mass generation in minimal extensions of the Standard Model via sterile fermions with (small) total lepton number violation. Within the framework of Inverse and Linear Seesaw models, the small lepton number violating parameters set the mass scale of the active neutrinos, the efficiency of leptogenesis through a small mass splitting between pairs of sterile fermions as well as the mass scale of a sterile neutrino dark matter candidate. We provide an improved parametrization of these seesaw models taking into account existing experimental constraints and derive a linearized system of Boltzmann equations to describe the leptogenesis process, which allows for an efficient investigation of the parameter space. This in particular enables us to perform a systematic study of the strong washout regime of leptogenesis. Our study reveals that one can have a successful leptogenesis at the temperature of the electroweak scale through oscillations between two sterile states with a natural origin of the (necessary) strong degeneracy in their mass spectrum. The minimal model however requires a non-standard cosmological history to account for the relic dark matter. Finally, we discuss the prospect for neutrinoless double beta decay and for testing, in future experiments, the values of mass and different active-sterile mixings required for successful leptogenesis.

Neutrino oscillations make their first appearance in OPERA

CERN Multimedia

CERN Bulletin

2010-01-01

1400 metres underground in the INFN Gran Sasso Laboratory, the Opera experiment has just observed its first candidate for neutrino oscillation – the phenomenon that confirms that neutrinos have mass. It is the first time that an experiment has observed the direct appearance of the new type of neutrinos produced in the oscillation. Opera uses a dedicated beam produced at CERN’s Super Proton Synchrotron (SPS).   Tracks of first candidate event observed by the OPERA experiment. Neutrinos, abundant in cosmic rays, are involved in several of the nuclear reactions that take place in the Sun, and also in radioactive decays. Numerous as they are, they continue to hold many secrets for scientists. One is the fact that the three types of neutrinos—electron, muon and tau neutrinos—can change into each another. This physical phenomenon, known as neutrino ‘oscillations’, was originally described in an article by Bruno Pontecorvo and Vla...

The number density of a charged relic

Energy Technology Data Exchange (ETDEWEB)

Berger, C.F. [Massachusetts Institute of Technology, Cambridge, MA (United States). Center for Theoretical Physics]|[California Univ., Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics; Covi, L. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kraml, S. [CNRS/IN2P3, Grenoble (France). Lab. de Physique Subatomique et de Cosmologie; Palorini, F. [Lyon Univ., UCBL, CNRS/IN2P3, Villeurbanne (France). IPN de Lyon

2008-07-15

We investigate scenarios in which a charged, long-lived scalar particle decouples from the primordial plasma in the Early Universe. We compute the number density at time of freeze-out considering both the cases of abelian and non-abelian interactions and including the effect of Sommerfeld enhancement at low initial velocity. We also discuss as extreme case the maximal cross section that fulfils the unitarity bound. We then compare these number densities to the exotic nuclei searches for stable relics and to the BBN bounds on unstable relics and draw conclusions for the cases of a stau or stop NLSP in supersymmetric models with a gravitino or axino LSP. (orig.)

The number density of a charged relic

International Nuclear Information System (INIS)

Berger, C.F.; Kraml, S.; Palorini, F.

2008-07-01

We investigate scenarios in which a charged, long-lived scalar particle decouples from the primordial plasma in the Early Universe. We compute the number density at time of freeze-out considering both the cases of abelian and non-abelian interactions and including the effect of Sommerfeld enhancement at low initial velocity. We also discuss as extreme case the maximal cross section that fulfils the unitarity bound. We then compare these number densities to the exotic nuclei searches for stable relics and to the BBN bounds on unstable relics and draw conclusions for the cases of a stau or stop NLSP in supersymmetric models with a gravitino or axino LSP. (orig.)

Radio observations of the double-relic galaxy cluster Abell 1240

Science.gov (United States)

Hoang, D. N.; Shimwell, T. W.; van Weeren, R. J.; Intema, H. T.; Röttgering, H. J. A.; Andrade-Santos, F.; Akamatsu, H.; Bonafede, A.; Brunetti, G.; Dawson, W. A.; Golovich, N.; Best, P. N.; Botteon, A.; Brüggen, M.; Cassano, R.; de Gasperin, F.; Hoeft, M.; Stroe, A.; White, G. J.

2018-05-01

We present LOFAR 120 - 168 MHz images of the merging galaxy cluster Abell 1240 that hosts double radio relics. In combination with the GMRT 595 - 629 MHz and VLA 2 - 4 GHz data, we characterised the spectral and polarimetric properties of the radio emission. The spectral indices for the relics steepen from their outer edges towards the cluster centre and the electric field vectors are approximately perpendicular to the major axes of the relics. The results are consistent with the picture that these relics trace large-scale shocks propagating outwards during the merger. Assuming diffusive shock acceleration (DSA), we obtain shock Mach numbers of M=2.4 and 2.3 for the northern and southern shocks, respectively. For M≲ 3 shocks, a pre-existing population of mildly relativistic electrons is required to explain the brightness of the relics due to the high (>10 per cent) particle acceleration efficiency required. However, for M≳ 4 shocks the required efficiency is ≳ 1% and ≳ 0.5%, respectively, which is low enough for shock acceleration directly from the thermal pool. We used the fractional polarization to constrain the viewing angle to ≥53 ± 3° and ≥39 ± 5° for the northern and southern shocks, respectively. We found no evidence for diffuse emission in the cluster central region. If the halo spans the entire region between the relics (˜1.8 Mpc) our upper limit on the power is P1.4GHz = (1.4 ± 0.6) × 1023 W Hz-1 which is approximately equal to the anticipated flux from a cluster of this mass. However, if the halo is smaller than this, our constraints on the power imply that the halo is underluminous.

An Account of Translation of Relics: the Writings of Alonso de Cartagena

Directory of Open Access Journals (Sweden)

Luis Fernández Gallardo

2018-01-01

Full Text Available The narratives of translation of relics is a genre of devotional literature that didn´t develop extensively in Medieval Castile. But Alonso de Cartagena contributed to it remarkably. In 1453, during a pastoral visit, he decided to move the relics of St. Juliana to a more honorable place. He wrote an account of these facts that adjusts strictly to the features of the genre. This vernacular text contains an exposition about the cult of saints and their relics, which has an intense Thomist inspiration: it sets theological questions with precision and clarity. The provisions on the decoration of the chapel of the relics offer an interesting testimony of the debate on religious image which is then developed in Castile.

a Review of Digital Watermarking and Copyright Control Technology for Cultural Relics

Science.gov (United States)

Liu, H.; Hou, M.; Hu, Y.

2018-04-01

With the rapid growth of the application and sharing of the 3-D model data in the protection of cultural relics, the problem of Shared security and copyright control of the three-dimensional model of cultural relics is becoming increasingly prominent. Followed by a digital watermarking copyright control has become the frontier technology of 3-D model security protection of cultural relics and effective means, related technology research and application in recent years also got further development. 3-D model based on cultural relics digital watermarking and copyright control technology, introduces the research background and demand, its unique characteristics were described, and its development and application of the algorithm are discussed, and the prospects of the future development trend and some problems and the solution.

Radiological data acquisition, investigation and evaluation of mining relics

International Nuclear Information System (INIS)

1992-01-01

Within the scope of a Federal Project, the environmental radioactivity and the radon concentration in buildings caused by mining relics in the new Federal Lands of Germany are investigated. In the first phase of the project, about 8000 relics of former mining were identified by analysing existing documents, categorised, and recorded in a special data bank. Thereby, 'areas of suspicion' of 1500 km 2 spaciously defined in the beginning could be reduced to 'areas of investigation' of 250 km 2 now to be examined in close coordination with the land and district authorities by a programme gradually adapted to the radiological significance of the relics. Experience with site-specific measuring programmes have already been gained through three pilot projects at typical sites of former mining activities. Recommendations of the German Radiation Protection Commission serve for the evaluation of the results. By the measuring programme for radon in buildings of mining and geological predestined regions more than 25000 buildings of 210 communities have been investigated. The results confirm the expected prevailing influence of the geologic underground on the radon concentration. Extreme values are observed where direct connections additionally exist to mining relics in the ground. (orig./HP) With 11 figs. in annex [de

Neutrino oscillations in dense neutrino gases

International Nuclear Information System (INIS)

Samuel, S.

1993-01-01

We consider oscillations of neutrinos under conditions in which the neutrino density is sufficiently large that neutrino-neutrino interactions cannot be neglected. A formalism is developed to treat this highly nonlinear system. Numerical analysis reveals a rich array of phenomena. In certain gases, a self-induced Mikheyev-Smirnov-Wolfenstein effect occurs in which electron neutrinos are resonantly converted into muon neutrinos. In another relatively low-density gas, an unexpected parametric resonant conversion takes place. Finally, neutrino-neutrino interactions maintain coherence in one system for which a priori one expected decoherence

Cosmic relics from the big bang

International Nuclear Information System (INIS)

Hall, L.J.

1988-12-01

A brief introduction to the big bang picture of the early universe is given. Dark matter is discussed; particularly its implications for elementary particle physics. A classification scheme for dark matter relics is given. 21 refs., 11 figs., 1 tab

Cosmic relics from the big bang

Energy Technology Data Exchange (ETDEWEB)

Hall, L.J.

1988-12-01

A brief introduction to the big bang picture of the early universe is given. Dark matter is discussed; particularly its implications for elementary particle physics. A classification scheme for dark matter relics is given. 21 refs., 11 figs., 1 tab.

Another shock for the Bullet cluster, and the source of seed electrons for radio relics

Science.gov (United States)

Shimwell, Timothy W.; Markevitch, Maxim; Brown, Shea; Feretti, Luigina; Gaensler, B. M.; Johnston-Hollitt, M.; Lage, Craig; Srinivasan, Raghav

2015-05-01

With Australia Telescope Compact Array observations, we detect a highly elongated Mpc-scale diffuse radio source on the eastern periphery of the Bullet cluster 1E 0657-55.8, which we argue has the positional, spectral and polarimetric characteristics of a radio relic. This powerful relic (2.3 ± 0.1 × 1025 W Hz-1) consists of a bright northern bulb and a faint linear tail. The bulb emits 94 per cent of the observed radio flux and has the highest surface brightness of any known relic. Exactly coincident with the linear tail, we find a sharp X-ray surface brightness edge in the deep Chandra image of the cluster - a signature of a shock front in the hot intracluster medium (ICM), located on the opposite side of the cluster to the famous bow shock. This new example of an X-ray shock coincident with a relic further supports the hypothesis that shocks in the outer regions of clusters can form relics via diffusive shock (re-)acceleration. Intriguingly, our new relic suggests that seed electrons for reacceleration are coming from a local remnant of a radio galaxy, which we are lucky to catch before its complete disruption. If this scenario, in which a relic forms when a shock crosses a well-defined region of the ICM polluted with aged relativistic plasma - as opposed to the usual assumption that seeds are uniformly mixed in the ICM - is also the case for other relics, this may explain a number of peculiar properties of peripheral relics.

Analysis on the environment of cultural relic as tourist attraction--take Yungang Grottoes as an example

Science.gov (United States)

Xiangdong, Zhu; Jie, Bai

2018-03-01

Cultural relic resources are precious non-renewable resources and an important cornerstone for the development of cultural relic tourism. With the rapid development of tourism industry, the native environment of cultural relics is being squeezed constantly. Meanwhile, under the economic interests, cultural relic’s protection and heritage tourism contradictions continue to intensify. The present era which the architectural style is convergence, cultural relics protection is simplistic, restore historical sites blindly and other. In the historical process of economic development and the acceleration of new-type urbanization, the heritage industry faces the dual tasks and development challenges. As cultural relic protection workers, investigation of the utilization of cultural relic’s tourist attractions, investigation and analysis of the Yungang Grottoes, indicating cultural relics as a tourist attraction, not only to strengthen the protection of ontology, also should attach importance to the coordinated development of the protection of cultural relics and the utilization of tourism.

Relic gravitons and viscous cosmologies

International Nuclear Information System (INIS)

Cataldo, Mauricio; Mella, Patricio

2006-01-01

Previously it was shown that there exists a class of viscous cosmological models which violate the dominant energy condition for a limited amount of time after which they are smoothly connected to the ordinary radiation era (which preserves the dominant energy conditions). This violation of the dominant energy condition at an early cosmological epoch may influence the slopes of energy spectra of relic gravitons that might be of experimental relevance. However, the bulk viscosity coefficient of these cosmologies became negative during the ordinary radiation era, and then the entropy of the sources driving the geometry decreases with time. We show that in the presence of viscous sources with a linear barotropic equation of state p=γρ we get viscous cosmological models with positive bulk viscous stress during all their evolution, and hence the matter entropy increases with the expansion time. In other words, in the framework of viscous cosmologies, there exist isotropic models compatible with the standard second law of thermodynamics which also may influence the slopes of energy spectra of relic gravitons

Neutrino masses and neutrino oscillations

CERN Document Server

Di Lella, L

2000-01-01

These lectures review direct measurements of neutrino masses and the status of neutrino oscillation searches using both natural neutrino sources (the Sun and cosmic rays interacting in the Earth atmosphere) and artificial neutrinos (produced by nuclear reactors and accelerators). Finally, future experiments and plans are presented. (68 refs).

Relating the baryon asymmetry to the thermal relic dark matter density

International Nuclear Information System (INIS)

McDonald, John

2011-01-01

We present a generic framework, baryomorphosis, which modifies the baryon asymmetry to be naturally of the order of a typical thermal relic weakly interacting massive particle (WIMP) density. We consider a simple scalar-based model to show how this is possible. This model introduces a sector in which a large initial baryon asymmetry is injected into particles ('annihilons'), φ B , φ-circumflex B , of mass ∼100 GeV-1 TeV. φ B φ-circumflex B annihilations convert the initial φ B , φ-circumflex B asymmetry to a final asymmetry with a thermal relic WIMP-like density. This subsequently decays to a conventional baryon asymmetry whose magnitude is naturally related to the density of thermal relic WIMP dark matter. In this way the two coincidences of baryons and dark matter, i.e. why their densities are similar to each other and why they are both similar to a WIMP thermal relic density (the 'WIMP miracle'), may be understood. The model may be tested by the production of annihilons at colliders.

Using Big Bang Nucleosynthesis to extend CMB probes of neutrino physics

Energy Technology Data Exchange (ETDEWEB)

Shimon, M.; Miller, N.J.; Fuller, G.M.; Keating, B.G. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA, 92093 (United States); Kishimoto, C.T. [Department of Physics and Astronomy, University of California, Los Angeles, CA, 90095 (United States); Smith, C.J., E-mail: meirs@mamacass.ucsd.edu, E-mail: nmiller@physics.ucsd.edu, E-mail: ckishimo@physics.ucsd.edu, E-mail: christel.smith@asu.edu, E-mail: gfuller@ucsd.edu, E-mail: bkeating@ucsd.edu [Department of Physics, Arizona State University, Tempe, AZ, 85287 (United States)

2010-05-01

We present calculations showing that upcoming Cosmic Microwave Background (CMB) experiments will have the power to improve on current constraints on neutrino masses and provide new limits on neutrino degeneracy parameters. The latter could surpass those derived from Big Bang Nucleosynthesis (BBN) and the observationally-inferred primordial helium abundance. These conclusions derive from our Monte Carlo Markov Chain (MCMC) simulations which incorporate a full BBN nuclear reaction network. This provides a self-consistent treatment of the helium abundance, the baryon number, the three individual neutrino degeneracy parameters and other cosmological parameters. Our analysis focuses on the effects of gravitational lensing on CMB constraints on neutrino rest mass and degeneracy parameter. We find for the PLANCK experiment that total (summed) neutrino mass M{sub ν} > 0.29 eV could be ruled out at 2σ or better. Likewise neutrino degeneracy parameters ξ{sub ν{sub e}} > 0.11 and |ξ{sub ν{sub μ{sub /{sub τ}}}}| > 0.49 could be detected or ruled out at 2σ confidence, or better. For POLARBEAR we find that the corresponding detectable values are M{sub ν} > 0.75 eV, ξ{sub ν{sub e}} > 0.62, and |ξ{sub ν{sub μ{sub /{sub τ}}}}| > 1.1, while for EPIC we obtain M{sub ν} > 0.20 eV, ξ{sub ν{sub e}} > 0.045, and |ξ{sub ν{sub μ{sub /{sub τ}}}}| > 0.29. Our forcast for EPIC demonstrates that CMB observations have the potential to set constraints on neutrino degeneracy parameters which are better than BBN-derived limits and an order of magnitude better than current WMAP-derived limits.

Gravitino dark matter from increased thermal relic particles

International Nuclear Information System (INIS)

Okada, Nobuchika; Seto, Osamu

2008-01-01

We investigate the so-called superWIMP scenario with the gravitino as the lightest supersymmetric particle (LSP) in the context of nonstandard cosmology, in particular, brane world cosmology. As a candidate of the next-to-LSP (NLSP), we examine the slepton and the sneutrino. Brane world cosmological effects dramatically enhance the relic density of the slepton or sneutrino NLSP, so that the NLSP with mass of order 100 GeV can provide the correct abundance of gravitino dark matter through its decay. We find that with an appropriate five-dimensional Planck mass, this scenario can be realized consistently with the constraints from big bang nucleosynthesis for both NLSP candidates of the slepton and the sneutrino. The big bang nucleosynthesis constraints for the slepton NLSP are more stringent than that for the sneutrino; as the result, the gravitino must be rather warm in the slepton NLSP case. The energy density of the gravitino produced by thermal scattering is highly suppressed and negligible due to the brane world cosmological effects

Light sterile neutrino sensitivity at the nuSTORM facility

Energy Technology Data Exchange (ETDEWEB)

Adey, D.; Agarwalla, S. K.; Ankenbrandt, C. M.; Asfandiyarov, R.; Back, J. J.; Barker, G.; Baussan, E.; Bayes, R.; Bhadra, S.; Blackmore, V.; Blondel, A.; Bogacz, S. A.; Booth, C.; Boyd, S. B.; Bramsiepe, S. G.; Bravar, A.; Brice, S. J.; Bross, A. D.; Cadoux, F.; Cease, H.; Cervera, A.; Cobb, J.; Colling, D.; Coloma, P.; Coney, L.; Dobbs, A.; Dobson, J.; Donini, A.; Dornan, P.; Dracos, M.; Dufour, F.; Edgecock, R.; Geelhoed, M.; Uchida, M. A.; Ghosh, T.; Gómez-Cadenas, J. J.; de Gouvêa, A.; Haesler, A.; Hanson, G.; Harrison, P. F.; Hartz, M.; Hernández, P.; Hernando Morata, J. A.; Hodgson, P.; Huber, P.; Izmaylov, A.; Karadzhov, Y.; Kobilarcik, T.; Kopp, J.; Kormos, L.; Korzenev, A.; Kuno, Y.; Kurup, A.; Kyberd, P.; Lagrange, J. B.; Laing, A.; Liu, A.; Link, J. M.; Long, K.; Mahn, K.; Mariani, C.; Martin, C.; Martin, J.; McCauley, N.; McDonald, K. T.; Mena, O.; Mishra, S. R.; Mokhov, N.; Morfín, J.; Mori, Y.; Murray, W.; Neuffer, D.; Nichol, R.; Noah, E.; Palmer, M. A.; Parke, S.; Pascoli, S.; Pasternak, J.; Plunkett, R.; Popovic, M.; Ratoff, P.; Ravonel, M.; Rayner, M.; Ricciardi, S.; Rogers, C.; Rubinov, P.; Santos, E.; Sato, A.; Sen, T.; Scantamburlo, E.; Sedgbeer, J. K.; Smith, D. R.; Smith, P. J.; Sobczyk, J. T.; Søby, L.; Soler, F. J. P.; Sorel, M.; Snopok, P.; Stamoulis, P.; Stanco, L.; Striganov, S.; Tanaka, H. A.; Taylor, I. J.; Touramanis, C.; Tunnell, C. D.; Uchida, Y.; Vassilopoulos, N.; Wascko, M. O.; Weber, A.; Wilking, M. J.; Wildner, E.; Winter, W.

2014-04-01

A facility that can deliver beams of electron and muon neutrinos from the decay of a stored muon beam has the potential to unambiguously resolve the issue of the evidence for light sterile neutrinos that arises in short-baseline neutrino oscillation experiments and from estimates of the effective number of neutrino flavors from fits to cosmological data. In this paper, we show that the nuSTORM facility, with stored muons of 3.8GeV/c±10%, will be able to carry out a conclusive muon neutrino appearance search for sterile neutrinos and test the LSND and MiniBooNE experimental signals with 10σ sensitivity, even assuming conservative estimates for the systematic uncertainties. This experiment would add greatly to our knowledge of the contribution of light sterile neutrinos to the number of effective neutrino flavors from the abundance of primordial helium production and from constraints on neutrino energy density from the cosmic microwave background. The appearance search is complemented by a simultaneous muon neutrino disappearance analysis that will facilitate tests of various sterile neutrino models.

Imprints of relic gravitational waves in cosmic microwave background radiation

International Nuclear Information System (INIS)

Baskaran, D.; Grishchuk, L. P.; Polnarev, A. G.

2006-01-01

A strong variable gravitational field of the very early Universe inevitably generates relic gravitational waves by amplifying their zero-point quantum oscillations. We begin our discussion by contrasting the concepts of relic gravitational waves and inflationary 'tensor modes'. We explain and summarize the properties of relic gravitational waves that are needed to derive their effects on cosmic microwave background (CMB) temperature and polarization anisotropies. The radiation field is characterized by four invariants I, V, E, B. We reduce the radiative transfer equations to a single integral equation of Voltairre type and solve it analytically and numerically. We formulate the correlation functions C l XX ' for X, X ' =T, E, B and derive their amplitudes, shapes and oscillatory features. Although all of our main conclusions are supported by exact numerical calculations, we obtain them, in effect, analytically by developing and using accurate approximations. We show that the TE correlation at lower l's must be negative (i.e. an anticorrelation), if it is caused by gravitational waves, and positive if it is caused by density perturbations. This difference in TE correlation may be a signature more valuable observationally than the lack or presence of the BB correlation, since the TE signal is about 100 times stronger than the expected BB signal. We discuss the detection by WMAP of the TE anticorrelation at l≅30 and show that such an anticorrelation is possible only in the presence of a significant amount of relic gravitational waves (within the framework of all other common assumptions). We propose models containing considerable amounts of relic gravitational waves that are consistent with the measured TT, TE and EE correlations

TURBULENT COSMIC-RAY REACCELERATION AT RADIO RELICS AND HALOS IN CLUSTERS OF GALAXIES

International Nuclear Information System (INIS)

Fujita, Yutaka; Takizawa, Motokazu; Yamazaki, Ryo; Akamatsu, Hiroki; Ohno, Hiroshi

2015-01-01

Radio relics are synchrotron emission found on the periphery of galaxy clusters. From the position and the morphology, it is often believed that the relics are generated by cosmic-ray (CR) electrons accelerated at shocks through a diffusive shock acceleration (DSA) mechanism. However, some radio relics have harder spectra than the prediction of the standard DSA model. One example is observed in the cluster 1RXS J0603.3+4214, which is often called the “Toothbrush Cluster.” Interestingly, the position of the relic is shifted from that of a possible shock. In this study, we show that these discrepancies in the spectrum and the position can be solved if turbulent (re)acceleration is very effective behind the shock. This means that for some relics turbulent reacceleration may be the main mechanism to produce high-energy electrons, contrary to the common belief that it is the DSA. Moreover, we show that for efficient reacceleration, the effective mean free path of the electrons has to be much smaller than their Coulomb mean free path. We also study the merging cluster 1E 0657−56, or the “Bullet Cluster,” in which a radio relic has not been found at the position of the prominent shock ahead of the bullet. We indicate that a possible relic at the shock is obscured by the observed large radio halo that is generated by strong turbulence behind the shock. We propose a simple explanation of the morphological differences of radio emission among the Toothbrush, the Bullet, and the Sausage (CIZA J2242.8+5301) Clusters

Thermal relic dark matter beyond the unitarity limit

Energy Technology Data Exchange (ETDEWEB)

Harigaya, Keisuke [Berkeley Center for Theoretical Physics, Department of Physics, University of California,Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory,Berkeley, CA 94720 (United States); Ibe, Masahiro [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); ICRR, The University of Tokyo,Kashiwa, Chiba 277-8582 (Japan); Kaneta, Kunio [Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS),Daejeon 34051 (Korea, Republic of); Nakano, Wakutaka; Suzuki, Motoo [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); ICRR, The University of Tokyo,Kashiwa, Chiba 277-8582 (Japan)

2016-08-25

We discuss a simple model of thermal relic dark matter whose mass can be much larger than the so-called unitarity limit on the mass of point-like particle dark matter. The model consists of new strong dynamics with one flavor of fermions in the fundamental representation which is much heavier than the dynamical scale of the new strong dynamics. Dark matter is identified with the lightest baryonic hadron of the new dynamics. The baryonic hadrons annihilate into the mesonic hadrons of the new strong dynamics when they have large radii. Resultantly, thermal relic dark matter with a mass in the PeV range is possible.

The 'relics of Joan of Arc'

DEFF Research Database (Denmark)

Charlier, P.; Poupon, J.; Eb, A.

2010-01-01

Archaeological remains can provide concrete cases, making it possible to develop, refine or validate medico-legal techniques. In the case of the so-called 'Joan of Arc's relics' (a group of bone and archaeological remains known as the 'Bottle of Chinon'), 14 specialists analysed the samples such ...

Neutrinos in cosmology

International Nuclear Information System (INIS)

Tayler, R.J.

1983-01-01

The standard model of the hot big bang cosmological theory, which appears to be in agreement, at least qualitatively, with the observed properties of the Universe, assumes that the early Universe was homogeneous and isotropic and that it has been continuously expanding from a state characterized by very high temperature and density, where matter and radiation were to a good approximation in a state of thermodynamic equilibrium. In this standard model, it is assumed that baryon number, charge number and the various lepton numbers are all conserved. Only the baryon number is non-zero and this, expressed as the ratio of the net number of baryons (baryons minus antibaryons) to the number of photons per unit volume is the undefined parameter in the model. The author discusses the importance of knowing how many types of neutrinos there are with regard to the He 4 abundance, and the implication of a small, non-zero neutrino mass. (Auth.)

Dark Radiation or Warm Dark Matter from long lived particle decays in the light of Planck

International Nuclear Information System (INIS)

Di Bari, Pasquale; King, Stephen F.; Merle, Alexander

2013-01-01

Although Planck data supports the standard ΛCDM model, it still allows for the presence of Dark Radiation corresponding up to about half an extra standard neutrino species. We propose a scenario for obtaining a fractional “effective neutrino species” from a thermally produced particle which decays into a much lighter stable relic plus standard fermions. At lifetimes much longer than ∼1 s, both the relic particles and the non-thermal neutrino component contribute to Dark Radiation. By increasing the stable-to-unstable particle mass ratio, the relic particle no longer acts as Dark Radiation but instead becomes a candidate for Warm Dark Matter with mass O(1 keV–100 GeV). In both cases it is possible to address the lithium problem

Collective neutrino oscillations and neutrino wave packets

Energy Technology Data Exchange (ETDEWEB)

Akhmedov, Evgeny; Lindner, Manfred [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Kopp, Joachim, E-mail: akhmedov@mpi-hd.mpg.de, E-mail: jkopp@uni-mainz.de, E-mail: lindner@mpi-hd.mpg.de [PRISMA Cluster of Excellence and Mainz Institute for Theoretical Physics, Johannes Gutenberg University, 55099 Mainz (Germany)

2017-09-01

Effects of decoherence by wave packet separation on collective neutrino oscillations in dense neutrino gases are considered. We estimate the length of the wave packets of neutrinos produced in core collapse supernovae and the expected neutrino coherence length, and then proceed to consider the decoherence effects within the density matrix formalism of neutrino flavour transitions. First, we demonstrate that for neutrino oscillations in vacuum the decoherence effects are described by a damping term in the equation of motion of the density matrix of a neutrino as a whole (as contrasted to that of the fixed-momentum components of the neutrino density matrix). Next, we consider neutrino oscillations in ordinary matter and dense neutrino backgrounds, both in the adiabatic and non-adiabatic regimes. In the latter case we study two specific models of adiabaticity violation—one with short-term and another with extended non-adiabaticity. It is demonstrated that, while in the adiabatic case a damping term is present in the equation of motion of the neutrino density matrix (just like in the vacuum oscillation case), no such term in general appears in the non-adiabatic regime.

Detecting supernova neutrinos in Daya Bay Neutrino Laboratory

International Nuclear Information System (INIS)

Huang Mingyang; Guo Xinheng; Yang Binglin

2011-01-01

While detecting supernova neutrinos in the Daya Bay neutrino laboratory, several supernova neutrino effects need to be considered, including the supernova shock effects, the neutrino collective effects, the Mikheyev-Smirnov-Wolfenstein (MSW) effects, and the Earth matter effects. The phenomena of neutrino oscillation is affected by the above effects. Using some ratios of the event numbers of different supernova neutrinos, we propose some possible methods to identify the mass hierarchy and acquire information about the neutrino mixing angle θ13 and neutrino masses. (authors)

On the absence of radio haloes in clusters with double relics

Science.gov (United States)

Bonafede, A.; Cassano, R.; Brüggen, M.; Ogrean, G. A.; Riseley, C. J.; Cuciti, V.; de Gasperin, F.; Golovich, N.; Kale, R.; Venturi, T.; van Weeren, R. J.; Wik, D. R.; Wittman, D.

2017-09-01

Pairs of radio relics are believed to form during cluster mergers, and are best observed when the merger occurs in the plane of the sky. Mergers can also produce radio haloes, through complex processes likely linked to turbulent re-acceleration of cosmic ray electrons. However, only some clusters with double relics also show a radio halo. Here, we present a novel method to derive upper limits on the radio halo emission, and analyse archival X-ray Chandra data, as well as galaxy velocity dispersions and lensing data, in order to understand the key parameter that switches on radio halo emission. We place upper limits on the halo power below the P1.4 GHz-M500 correlation for some clusters, confirming that clusters with double relics have different radio properties. Computing X-ray morphological indicators, we find that clusters with double relics are associated with the most disturbed clusters. We also investigate the role of different mass-ratios and time-since-merger. Data do not indicate that the merger mass-ratio has an impact on the presence or absence of radio haloes (the null hypothesis that the clusters belong to the same group cannot be rejected). However, the data suggest that the absence of radio haloes could be associated with early and late mergers, but the sample is too small to perform a statistical test. Our study is limited by the small number of clusters with double relics. Future surveys with LOFAR, ASKAP, MeerKat and SKA will provide larger samples to better address this issue.

Neutrinos

CERN Multimedia

CERN. Geneva

2004-01-01

The Standard Model predicts that the neutrinos are massless and do not mix. Generic extensions of the Standard Model predict that neutrinos are massive (but, very likely, much lighter than the charged fermions). Therefore, the search for neutrino masses and mixing tests the Standard Model and probes new phasics. Measurements of various features of the fluxes of atmospheric, solar and, more recently, reactor neutrinos have provided evidence for neutrino oscillations and therefore for neutrino masses and mixing. These results have significant theoretical implications: new physics exists, and its scale can be estimated. There are interesting lessons for grand unified theories and for models of extra dimensions. The measured neutrino flavor parameters pose a challenge to flavor models.

“The Godly Greedy Appetite”: New Relic Circulation in the Early Modern World

Directory of Open Access Journals (Sweden)

Igor Pérez Tostado

2017-05-01

Full Text Available Having lost all monasteries and a good deal of its medieval Christian movable assets, England became one of the greatest producers of new Catholic relics during the sixteenth and seventeenth centuries. This article aims to look, from a material point of view, at the circulation and consumption of English relics on the Catholic continent. In this case, these products were created because of violence and circulated as an answer to it. Gifts and the exchange of relics served to obtain support for the exiled Catholics and for the institutions providing for their education created in the continent, and allowed them to participate in the necropolitics of the Spanish Monarchy. Relics, artifacts and printed and manuscript narratives brought back from all over the world helped construct a selfimage of an English Catholic as a necrocommunity imbued by a sense of historical continuity and connected to a global imagined community.

Constraints on lifetime and mass of heavy lepton neutrinos imposed by big bang nucleosynthesis

International Nuclear Information System (INIS)

Miyama, Shoken; Sato, Katsuhiko

1978-01-01

If there exist massive neutral leptons (heavy neutrinos), they would have been produced in thermal equilibrium in the early stages of the universe. The effects of their presence and decay on the big bang nucleosynthesis are investigated in detail and abundances of the products 4 He, 2 H and 7 Li are compared with the observed cosmic abundances. We have determined a region in the lifetime-mass diagram of the heavy neutrino which should be ruled out in order for the big bang nucleosynthesis not to conflict with observed abundances of the elements. In addition, if a lower limit of the lifetime obtained from the Weinberg-Salam type theory, tau>=6 x 10 7 (1 MeV/m sub(νh)) 5 sec, is assumed, where m sub(νh) is the mass of the heavy neutrino, the mass range of 70 eV< m sub(νh)<10 MeV is ruled out. The other constraints on the mass and the lifetime obtained from astrophysical considerations are also discussed and summarized. (author)

Neutrino problems proliferate (Neutrino 94 conference report)

International Nuclear Information System (INIS)

Gordon, Fraser

1994-01-01

The enigma of the neutrino continues. More than sixty years after its hesitant prediction by Pauli and forty years after its discovery by Reines and Cowan, the neutrino still refuses to give up all its secrets. The longer we travel down the neutrino road and the more we find out about these particles, the more problems we uncover en route. The present state of the neutrino mystery was highlighted at the Neutrino 94 meeting in Eilat, Israel, from 29 May to 3 June. It was a distinguished meeting, with the first morning including one session chaired by neutrino co-discoverer Fred Reines, and an introductory talk by muon-neutrino co-discoverer Leon Lederman. One figurehead neutrino personality conspicuously absent this time was Bruno Pontecorvo, who died last year and had attended the previous conference in the series, in Grenada, Spain, in 1992

Neutrino problems proliferate (Neutrino 94 conference report)

Energy Technology Data Exchange (ETDEWEB)

Gordon, Fraser

1994-09-15

The enigma of the neutrino continues. More than sixty years after its hesitant prediction by Pauli and forty years after its discovery by Reines and Cowan, the neutrino still refuses to give up all its secrets. The longer we travel down the neutrino road and the more we find out about these particles, the more problems we uncover en route. The present state of the neutrino mystery was highlighted at the Neutrino 94 meeting in Eilat, Israel, from 29 May to 3 June. It was a distinguished meeting, with the first morning including one session chaired by neutrino co-discoverer Fred Reines, and an introductory talk by muon-neutrino co-discoverer Leon Lederman. One figurehead neutrino personality conspicuously absent this time was Bruno Pontecorvo, who died last year and had attended the previous conference in the series, in Grenada, Spain, in 1992.

Convoluted ν-Signals on 114Cd Isotope from Astrophysical and Laboratory Neutrino Sources

Directory of Open Access Journals (Sweden)

Vaitsa Tsakstara

2015-01-01

Full Text Available At first, we evaluate scattering cross sections of low, and intermediate-energy neutrinos scattered off the 114 Cd isotope, the most abundant Cd isotope present also in the COBRA detector (CdTe and CdZnTe materials which aims to search for double beta decay events and neutrino observations at Gran Sasso laboratory (LNGS. The coherent ν-nucleus channel addressed here is the dominant reaction channel of the neutral current ν-nucleus scattering. Our ν-nucleus cross sections (calculated with a refinement of the quasiparticle random-phase approximation, QRPA refer to the gs→gs transitions for ν-energies εν≤100 MeV. Subsequently, simulated ν-signals on 114 Cd isotope are derived. Towards this purpose, the required folded cross section comes out of simulation techniques by employing several low, and intermediate-energy neutrino distributions of the astrophysical ν-sources, like the solar, supernova, and Earth neutrinos, as well as the laboratory neutrinos, the reactor neutrinos, the pion-muon stopped neutrinos, and the β-beam neutrinos.

Physics of neutrino flavor transformation through matter-neutrino resonances

Science.gov (United States)

Wu, Meng-Ru; Duan, Huaiyu; Qian, Yong-Zhong

2016-01-01

In astrophysical environments such as core-collapse supernovae and neutron star-neutron star or neutron star-black hole mergers where dense neutrino media are present, matter-neutrino resonances (MNRs) can occur when the neutrino propagation potentials due to neutrino-electron and neutrino-neutrino forward scattering nearly cancel each other. We show that neutrino flavor transformation through MNRs can be explained by multiple adiabatic solutions similar to the Mikheyev-Smirnov-Wolfenstein mechanism. We find that for the normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be sensitive to the shape of neutrino spectra and the adiabaticity of the system, but such sensitivity is absent for the inverted hierarchy.

Neutrino Physics

CERN Multimedia

CERN. Geneva; Dydak, Friedrich

2001-01-01

Starting from a review of theoretical concepts and experimental results in the early years of neutrino physics after Pauli's 1930 letter, today's double role of the neutrino as a cornerstone of the Standard Model and as a promising probe of physics beyond the Standard Model will be discussed. Topics comprise: - Conventional neutrino beams - Neutrinos as probes of the nucleon structure - Neutrinos from the universe - Dirac or Majorana neutrinos - Neutrino oscillations - MNS matrix - CP violation in the lepton sector - Neutrino factory.

Neutrino Physics

CERN Multimedia

CERN. Geneva. Audiovisual Unit

2002-01-01

Starting from a review of theoretical concepts and experimental results in the early years of neutrino physics after Pauli's 1930 letter, today's double role of the neutrino as a cornerstone of the Standard Model and as a promising probe of physics beyond the Standard Model will be discussed. Topics comprise: - Conventional neutrino beams - Neutrinos as probes of the nucleon structure - Neutrinos from the universe - Dirac or Majorana neutrinos - Neutrino oscillations - MNS matrix - CP violation in the lepton sector - Neutrino factory.

Neutrino mixing and future accelerator neutrino experiments

International Nuclear Information System (INIS)

Bilenky, S.M.

1992-01-01

No evidence for neutrino mixing has been obtained in experiments searching for oscillations with neutrinos from accelerators and reactors. The possible reason is that neutrino masses are too small to produce any sizable effects in the experiments with terrestrial neutrinos. We put forward here the point of view that the reason for that can be traced to the presence of a hierarchy of neutrino masses as well as strength of couplings between lepton families. (orig.)

Discussion of impact of relics activation on protection and utilization approaches-take the old summer palace as an example

Science.gov (United States)

Xiaoqi, J.

2015-08-01

As the popularization of cultural relics and the rapid development of cultural tourism industry, a large number of cultural relic tourism resources goes into public eyes. Activation of relics has became an important way for tourist to contact and understand culture relics. The way of how to properly interpret the historical sense and cultural uniqueness to the masses of tourists in order to achieve social service functions of relic resources has always been research focal point of site protection and utilization, so nowadays it has important significance to protection and utilization of heritage resources in our country. From the point of activation of relics and based on the analysis of resource characteristic, the paper in depth discuss ways of activation of relics of the Old Summer Palace, in order to provide reference for sustainable development of sites tourism in China.

Acquiring information about neutrino parameters by detecting supernova neutrinos

Science.gov (United States)

Huang, Ming-Yang; Guo, Xin-Heng; Young, Bing-Lin

2010-08-01

We consider the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein effects, the collective effects, and the Earth matter effects in the detection of type II supernova neutrinos on the Earth. It is found that the event number of supernova neutrinos depends on the neutrino mass hierarchy, the neutrino mixing angle θ13, and neutrino masses. Therefore, we propose possible methods to identify the mass hierarchy and acquire information about θ13 and neutrino masses by detecting supernova neutrinos. We apply these methods to some current neutrino experiments.

Neutrino cosmology

International Nuclear Information System (INIS)

Berstein, J.

1984-01-01

These lectures offer a self-contained review of the role of neutrinos in cosmology. The first part deals with the question 'What is a neutrino.' and describes in a historical context the theoretical ideas and experimental discoveries related to the different types of neutrinos and their properties. The basic differences between the Dirac neutrino and the Majorana neutrino are pointed out and the evidence for different neutrino 'flavours', neutrino mass, and neutrino oscillations is discussed. The second part summarizes current views on cosmology, particularly as they are affected by recent theoretical and experimental advances in high-energy particle physics. Finally, the close relationship between neutrino physics and cosmology is brought out in more detail, to show how cosmological constraints can limit the various theoretical possibilities for neutrinos and, more particularly, how increasing knowledge of neutrino properties can contribute to our understanding of the origin, history, and future of the Universe. The level is that of the beginning graduate student. (orig.)

Neutrino factories

International Nuclear Information System (INIS)

Dydak, F.

2002-01-01

The discovery of neutrino oscillations marks a major milestone in the history of neutrino physics, and opens a window to what lies beyond the Standard Model. Many current and forthcoming experiments will answer open questions; however, a major step forward, up to and possibly including CP violation in the neutrino mixing matrix, will be offered by the neutrino beams from a neutrino factory. The neutrino factory is a new concept for producing neutrino beams of unprecedented quality in terms of intensity, flavour composition, and precision of the beam parameters. These beams enable the exploration of otherwise inaccessible domains in neutrino oscillation physics by exploiting baselines of planetary dimensions. Suitable detectors pose formidable challenges but seem within reach with only moderate extrapolations from existing technologies. Although the main physics attraction of the neutrino factory is in the area of neutrino oscillations, an interesting spectrum of further opportunities ranging from high-precision, high-rate neutrino scattering to physics with high-intensity stopped muons comes with it

Neutrino physics

International Nuclear Information System (INIS)

Gil-Botella, I.

2011-01-01

The fundamental properties of neutrinos are reviewed in these lectures. The first part is focused on the basic characteristics of neutrinos in the Standard Model and how neutrinos are detected. Neutrino masses and oscillations are introduced and a summary of the most important experimental results on neutrino oscillations to date is provided. Then, present and future experimental proposals are discussed, including new precision reactor and accelerator experiments. Finally, different approaches for measuring the neutrino mass and the nature (Majorana or Dirac), of neutrinos are reviewed. The detection of neutrinos from supernovae explosions and the information that this measurement can provide are also summarized at the end. (author)

The case for mixed dark matter from sterile neutrinos

International Nuclear Information System (INIS)

Lello, Louis; Boyanovsky, Daniel

2016-01-01

Sterile neutrinos are SU(2) singlets that mix with active neutrinos via a mass matrix, its diagonalization leads to mass eigenstates that couple via standard model vertices. We study the cosmological production of heavy neutrinos via standard model charged and neutral current vertices under a minimal set of assumptions: i) the mass basis contains a hierarchy of heavy neutrinos , ii) these have very small mixing angles with the active (flavor) neutrinos, iii) standard model particles, including light (active-like) neutrinos are in thermal equilibrium. If kinematically allowed, the same weak interaction processes that produce active-like neutrinos also produce the heavier species. We introduce the quantum kinetic equations that describe their production, freeze out and decay and discuss the various processes that lead to their production in a wide range of temperatures assessing their feasibility as dark matter candidates. The final distribution function at freeze-out is a mixture of the result of the various production processes. We identify processes in which finite temperature collective excitations may lead to the production of the heavy species. As a specific example, we consider the production of heavy neutrinos in the mass range M h ∼< 140 MeV from pion decay shortly after the QCD crossover including finite temperature corrections to the pion form factors and mass. We consider the different decay channels that allow for the production of heavy neutrinos showing that their frozen distribution functions exhibit effects from ''kinematic entanglement'' and argue for their viability as mixed dark matter candidates. We discuss abundance, phase space density and stability constraints and argue that heavy neutrinos with lifetime τ> 1/ H 0 freeze out of local thermal equilibrium, and conjecture that those with lifetimes τ || 1/ H 0 may undergo cascade decay into lighter DM candidates and/or inject non-LTE neutrinos into the cosmic neutrino

The case for mixed dark matter from sterile neutrinos

Energy Technology Data Exchange (ETDEWEB)

Lello, Louis; Boyanovsky, Daniel, E-mail: lal81@pitt.edu, E-mail: boyan@pitt.edu [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States)

2016-06-01

Sterile neutrinos are SU(2) singlets that mix with active neutrinos via a mass matrix, its diagonalization leads to mass eigenstates that couple via standard model vertices. We study the cosmological production of heavy neutrinos via standard model charged and neutral current vertices under a minimal set of assumptions: i) the mass basis contains a hierarchy of heavy neutrinos , ii) these have very small mixing angles with the active (flavor) neutrinos, iii) standard model particles, including light (active-like) neutrinos are in thermal equilibrium. If kinematically allowed, the same weak interaction processes that produce active-like neutrinos also produce the heavier species. We introduce the quantum kinetic equations that describe their production, freeze out and decay and discuss the various processes that lead to their production in a wide range of temperatures assessing their feasibility as dark matter candidates. The final distribution function at freeze-out is a mixture of the result of the various production processes. We identify processes in which finite temperature collective excitations may lead to the production of the heavy species. As a specific example, we consider the production of heavy neutrinos in the mass range M {sub h} ∼< 140 MeV from pion decay shortly after the QCD crossover including finite temperature corrections to the pion form factors and mass. We consider the different decay channels that allow for the production of heavy neutrinos showing that their frozen distribution functions exhibit effects from ''kinematic entanglement'' and argue for their viability as mixed dark matter candidates. We discuss abundance, phase space density and stability constraints and argue that heavy neutrinos with lifetime τ> 1/ H {sub 0} freeze out of local thermal equilibrium, and conjecture that those with lifetimes τ || 1/ H {sub 0} may undergo cascade decay into lighter DM candidates and/or inject non-LTE neutrinos into the

Neutrino mass and the solar neutrino problem

International Nuclear Information System (INIS)

Wolfenstein, L.

1987-01-01

Theoretical ideas about neutrino mass based on grand-unified theories are reviewed. These give the see-saw formula in which neutrino mass is inversely proportional to a large mass scale M. For M between 10/sup 11/ and 10/sup 15/ Gev the study of solar neutrinos appears to be the best probe of neutrino masses and mixings

Neutrino magnetic moments and the solar neutrino problem

Energy Technology Data Exchange (ETDEWEB)

Akhmedov, E.Kh. [Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory]|[Valencia Univ. (Spain). Dept. de Fisica Teorica

1994-08-01

Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin-flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles (sin 2{theta}{sub o} {approx_gt} 0.2 the combined effect of the resonant spin-flavor precession and neutrino oscillations can result in an observable flux of solar {bar {nu}}{sub e}`s.

Neutrino magnetic moments and the solar neutrino problem

International Nuclear Information System (INIS)

Akhmedov, E.Kh.; Valencia Univ.

1994-01-01

Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin-flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles (sin 2θ o approx-gt 0.2 the combined effect of the resonant spin-flavor precession and neutrino oscillations can result in an observable flux of solar bar ν e 's

Physics of neutrino flavor transformation through matter–neutrino resonances

Energy Technology Data Exchange (ETDEWEB)

Wu, Meng-Ru, E-mail: mwu@theorie.ikp.physik.tu-darmstadt.de [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, Schlossgartenstraße 2, 64289 Darmstadt (Germany); Duan, Huaiyu, E-mail: duan@unm.edu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Qian, Yong-Zhong, E-mail: qian@physics.umn.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

2016-01-10

In astrophysical environments such as core-collapse supernovae and neutron star–neutron star or neutron star–black hole mergers where dense neutrino media are present, matter–neutrino resonances (MNRs) can occur when the neutrino propagation potentials due to neutrino–electron and neutrino–neutrino forward scattering nearly cancel each other. We show that neutrino flavor transformation through MNRs can be explained by multiple adiabatic solutions similar to the Mikheyev–Smirnov–Wolfenstein mechanism. We find that for the normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be sensitive to the shape of neutrino spectra and the adiabaticity of the system, but such sensitivity is absent for the inverted hierarchy.

Testing for new physics: neutrinos and the primordial power spectrum

Energy Technology Data Exchange (ETDEWEB)

Canac, Nicolas; Abazajian, Kevork N. [Department of Physics, University of California at Irvine, Irvine, CA 92697 (United States); Aslanyan, Grigor [Berkeley Center for Cosmological Physics, University of California, Berkeley, CA 94720 (United States); Easther, Richard [Department of Physics, University of Auckland, Private Bag 92019, Auckland (New Zealand); Price, Layne C., E-mail: ncanac@uci.edu, E-mail: aslanyan@berkeley.edu, E-mail: kevork@uci.edu, E-mail: r.easther@auckland.ac.nz, E-mail: laynep@andrew.cmu.edu [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)

2016-09-01

We test the sensitivity of neutrino parameter constraints from combinations of CMB and LSS data sets to the assumed form of the primordial power spectrum (PPS) using Bayesian model selection. Significantly, none of the tested combinations, including recent high-precision local measurements of H{sub 0} and cluster abundances, indicate a signal for massive neutrinos or extra relativistic degrees of freedom. For PPS models with a large, but fixed number of degrees of freedom, neutrino parameter constraints do not change significantly if the location of any features in the PPS are allowed to vary, although neutrino constraints are more sensitive to PPS features if they are known a priori to exist at fixed intervals in log k . Although there is no support for a non-standard neutrino sector from constraints on both neutrino mass and relativistic energy density, we see surprisingly strong evidence for features in the PPS when it is constrained with data from Planck 2015, SZ cluster counts, and recent high-precision local measurements of H{sub 0}. Conversely combining Planck with matter power spectrum and BAO measurements yields a much weaker constraint. Given that this result is sensitive to the choice of data this tension between SZ cluster counts, Planck and H{sub 0} measurements is likely an indication of unmodeled systematic bias that mimics PPS features, rather than new physics in the PPS or neutrino sector.

Neutrinos today

International Nuclear Information System (INIS)

Pontecorvo, B.; Bilen'kij, S.

1987-01-01

After the famous 1983 discovery of intermediate W, Z 0 bosons it may be stated with certainty that W, Z 0 are entirely responsible for the production of neutrinos and for their interactions. Neutrino physics notions are presented from this point of view in the first four introductory, quite elementary, paragraphs of the paper. The following seven paragraphs are more sophisticated. They are devoted to the neutrino mass and neutrino mixing question, which is the most actual problem in today neutrino physics. Vacuum neutrino oscillations, matter neutrino oscillations and netrinoless double-decay are considered. Solar neutrino physics is discussed in some detail from the point of view of vacuum and matter neutrino oscillations. The role played by neutrinos in the Universe is briefly considered. In the last paragraph there discussed the probable observation by different groups of neutrinos connected with the Supernova 1987 A: the first observation of gravitational star collapse (at least the general rehearsal of such observation) opens up a new era in astronomy of today exerimental physics and astrophysics is presented at the end of the paper in the form of a Table

Neutrino mass?

International Nuclear Information System (INIS)

Kayser, B.

1992-01-01

After arguing that we should be looking for evidence of neutrino mass, we illustrate the possible consequences of neutrino mass and mixing. We then turn to the question of whether neutrinos are their own antiparticles, and to the process which may answer this question: neutrinoless double beta decay. Next, we review the proposed Mikheyev-Smirnov-Wolfenstein solution to the solar neutrino problem, and discuss models which can generate neutrino electromagnetic moments large enough to play a role in the sun. Finally, we consider how the possible 17 keV neutrino, if real, would fit in with everything we know about neutrinos. (orig.)

Sterile neutrinos with eV masses in cosmology — How disfavoured exactly?

International Nuclear Information System (INIS)

Hamann, Jan; Hannestad, Steen; Raffelt, Georg G.; Wong, Yvonne Y.Y.

2011-01-01

We study cosmological models that contain sterile neutrinos with eV-range masses as suggested by reactor and short-baseline oscillation data. We confront these models with both precision cosmological data (probing the CMB decoupling epoch) and light-element abundances (probing the BBN epoch). In the minimal ΛCDM model, such sterile neutrinos are strongly disfavoured by current data because they contribute too much hot dark matter. However, if the cosmological framework is extended to include also additional relativistic degrees of freedom beyond the three standard neutrinos and the putative sterile neutrinos, then the hot dark matter constraint on the sterile states is considerably relaxed. A further improvement is achieved by allowing a dark energy equation of state parameter w e degeneracy. Any model containing eV-mass sterile neutrinos implies also strong modifications of other cosmological parameters. Notably, the inferred cold dark matter density can shift up by 20–75% relative to the standard ΛCDM value

Probing Neutrino Properties with Long-Baseline Neutrino Beams

International Nuclear Information System (INIS)

Marino, Alysia

2015-01-01

This final report on an Early Career Award grant began in April 15, 2010 and concluded on April 14, 2015. Alysia Marino's research is focussed on making precise measurements of neutrino properties using intense accelerator-generated neutrino beams. As a part of this grant, she is collaborating on the Tokai-to-Kamioka (T2K) long-baseline neutrino experiment, currently taking data in Japan, and on the Deep Underground Neutrino Experiment (DUNE) design effort for a future Long-Baseline Neutrino Facility (LBNF) in the US. She is also a member of the NA61/SHINE particle production experiment at CERN, but as that effort is supported by other funds, it will not be discussed further here. T2K was designed to search for the disappearance of muon neutrinos (?_?) and the appearance of electron neutrinos (?_e), using a beam of muon neutrino beam that travels 295 km across Japan towards the Super-Kamiokande detector. In 2011 T2K first reported indications of ?_e appearance, a previously unobserved mode of neutrino oscillations. In the past year, T2K has published a combined analysis of ?_? disappearance and ?_e appearance, and began collecting taking data with a beam of anti-neutrinos, instead of neutrinos, to search for hints of violation of the CP symmetry of the universe. The proposed DUNE experiment has similar physics goals to T2K, but will be much more sensitive due to its more massive detectors and new higher-intensity neutrino beam. This effort will be very high-priority particle physics project in the US over the next decade.

Physics of neutrino flavor transformation through matter–neutrino resonances

Directory of Open Access Journals (Sweden)

Meng-Ru Wu

2016-01-01

Full Text Available In astrophysical environments such as core-collapse supernovae and neutron star–neutron star or neutron star–black hole mergers where dense neutrino media are present, matter–neutrino resonances (MNRs can occur when the neutrino propagation potentials due to neutrino–electron and neutrino–neutrino forward scattering nearly cancel each other. We show that neutrino flavor transformation through MNRs can be explained by multiple adiabatic solutions similar to the Mikheyev–Smirnov–Wolfenstein mechanism. We find that for the normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be sensitive to the shape of neutrino spectra and the adiabaticity of the system, but such sensitivity is absent for the inverted hierarchy.

Neutrino sunshine

International Nuclear Information System (INIS)

Anon.

1993-01-01

Full text: On 10 June 1992, at the Neutrino 92 meeting in Grenada, Spain, Till Kirsten of Heidelberg's Max Planck Institute reported that neutrinos from sunshine had been seen. Most of the energy pumped out by the Sun comes from the fusion of protons into alpha particles, a process which also liberates neutrinos. While it takes about a million years for radiant energy formed in the deep interior of the Sun to fight its way to the surface, the highly penetrating neutrinos emerge almost immediately. It was in 1970 that Ray Davis and his team began taking data with a tank containing 615 tons of perchloroethylene (dry cleaning fluid) 1500 metres underground in the Homestake gold mine, South Dakota. The observed signal is consistently smaller than what is expected. This 'solar neutrino problem' was confirmed by the Kamioka mine experiment in Japan, looking at the Cherenkov light released by neutrino interactions in some 700 tons of water. However these experiments are only sensitive to a tiny high energy tail of the solar neutrino spectrum, and to understand what is going on needs measurements of the primary neutrinos from proton fusion. To get at these neutrinos, two large new detectors, using gallium and sensitive to these lower energy particles, have been built and commissioned in the past few years. The detectors are SAGE ('Soviet' American Gallium Experiment) in the Baksan Neutrino Observatory in the Caucasus, and Gallex, a team from France, Germany, Israel, Italy and the US in the Italian Gran Sasso underground Laboratory. At Grenada, Kirsten reported unmistakable signs of solar neutrinos of proton origin recorded in Gallex. SAGE and Gallex do not yet have enough data to unambiguously fix the level of primary solar neutrinos reaching the Earth, and the interpretation of the interim results tends to be subjective. However after 23 years of conditioning through watching the solar neutrinos' high energy tail, the prospect of a neutrino

Acquire information about neutrino parameters by detecting supernova neutrinos

OpenAIRE

Huang, Ming-Yang; Guo, Xin-Heng; Young, Bing-Lin

2010-01-01

We consider the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein (MSW) effects, the collective effects, and the Earth matter effects in the detection of type II supernova neutrinos on the Earth. It is found that the event number of supernova neutrinos depends on the neutrino mass hierarchy, the neutrino mixing angle $\\theta_{13}$, and neutrino masses. Therefore, we propose possible methods to identify the mass hierarchy and acquire information about $\\theta_{13}$ and neutrino masses ...

Mapping the ecological dimensions and potential distributions of endangered relic shrubs in western Ordos biodiversity center.

Science.gov (United States)

Zhu, Geng-Ping; Li, Hui-Qi; Zhao, Li; Man, Liang; Liu, Qiang

2016-05-20

Potential distributions of endemic relic shrubs in western Ordos were poorly mapped, which hindered our implementation of proper conservation. Here we investigated the applicability of ecological niche modeling for endangered relic shrubs to detect areas of priority for biodiversity conservation and analyze differences in ecological niche spaces used by relic shrubs. We applied ordination and niche modeling techniques to assess main environmental drivers of five endemic relic shrubs in western Ordos, namely, Ammopiptanthus mongolicus, Amygdalus mongolica, Helianthemum songaricum, Potaninia mongolica, and Tetraena mongolica. We calculated niche overlap metrics in gridded environmental spaces and compared geographical projections of ecological niches to determine similarities and differences of niches occupied by relic shrubs. All studied taxa presented different responses to environmental factors, which resulted in a unique combination of niche conditions. Precipitation availability and soil quality characteristics play important roles in the distributions of most shrubs. Each relic shrub is constrained by a unique set of environmental conditions, the distribution of one species cannot be implied by the distribution of another, highlighting the inadequacy of one-fits-all type of conservation measure. Our stacked habitat suitability maps revealed regions around Yellow River, which are highly suitable for most species, thereby providing high conservation value.

MULTI-FREQUENCY STUDIES OF RADIO RELICS IN THE GALAXY CLUSTERS A4038, A1664, AND A786

Energy Technology Data Exchange (ETDEWEB)

Kale, Ruta; Dwarakanath, K. S., E-mail: ruta@iucaa.ernet.in [Raman Research Institute, C. V. Raman Avenue, Sadashivanagar, Bangalore 560 080 (India)

2012-01-01

We present a multi-frequency study of radio relics associated with the galaxy clusters A4038, A1664, and A786. Radio images, integrated spectra, spectral index maps, and fits to the integrated spectra in the framework of the adiabatic compression model are presented. Images of the relic in A4038 at 150, 240, and 606 MHz with the Giant Meterwave Radio Telescope have revealed extended ultra-steep spectrum ({alpha} {approx} -1.8 to -2.7) emission of extent 210 Multiplication-Sign 80 kpc{sup 2}. The model of passively evolving radio lobes compressed by a shock fits the integrated spectrum best. The relic with a circular morphology at the outskirts of the cluster A1664 has an integrated spectral index of {approx} - 1.10 {+-} 0.06 and is best fit by the model of radio lobes lurking for {approx}4 Multiplication-Sign 10{sup 7} yr. The relic near A786 has a curved spectrum and is best fit by a model of radio lobes lurking for {approx}3 Multiplication-Sign 10{sup 7} yr. At 4.7 GHz, a compact radio source, possibly the progenitor of the A786 relic, is detected near the center of the radio relic. The A786 radio relic is thus likely a lurking radio galaxy rather than a site of cosmological shock as has been considered in earlier studies.

A combined treatment of neutrino decay and neutrino oscillations

International Nuclear Information System (INIS)

Lindner, Manfred; Ohlsson, Tommy; Winter, Walter

2001-01-01

Neutrino decay in vacuum has often been considered as an alternative to neutrino oscillations. Because nonzero neutrino masses imply the possibility of both neutrino decay and neutrino oscillations, we present a model-independent formal treatment of these combined scenarios. For that, we show for the example of Majoron decay that in many cases decay products are observable and may even oscillate. Furthermore, we construct a minimal scenario in which we study the physical implications of neutrino oscillations with intermediate decays

Experimental neutrino physics

CERN Document Server

Link, Jonathan M

2018-01-01

Neutrinos have a smaller mass than any other known particle and are the subject of intense recent studies, as well as this book. The author provides a coherent introduction to the necessary theoretical background and experimental methods used by modern neutrino physicists. It’s designed as a one-stop reference addressing what is currently known about the neutrino hypothesis, discovery of the neutrino, theory of weak interactions, solar neutrino puzzle, and neutrino oscillation. It then gives a detailed account of practical approaches for study of precision oscillations, neutrino mass and other neutrino properties, sterile neutrinos, and neutrino messengers from space and Earth’s interior.

Galaxy Formation in Sterile Neutrino Dark Matter Models

Science.gov (United States)

Menci, N.; Grazian, A.; Lamastra, A.; Calura, F.; Castellano, M.; Santini, P.

2018-02-01

We investigate galaxy formation in models with dark matter (DM) constituted by sterile neutrinos. Given their large parameter space, defined by the combinations of sterile neutrino mass {m}ν and mixing parameter {\\sin }2(2θ ) with active neutrinos, we focus on models with {m}ν =7 {keV}, consistent with the tentative 3.5 keV line detected in several X-ray spectra of clusters and galaxies. We consider (1) two resonant production models with {\\sin }2(2θ )=5 × {10}-11 and {\\sin }2(2θ )=2 × {10}-10, to cover the range of mixing parameters consistent with the 3.5 keV line; (2) two scalar-decay models, representative of the two possible cases characterizing such a scenario: a freeze-in and a freeze-out case. We also consider thermal warm DM with particle mass {m}X=3 {keV}. Using a semianalytic model, we compare the predictions for the different DM scenarios with a wide set of observables. We find that comparing the predicted evolution of the stellar mass function, the abundance of satellites of Milky Way–like galaxies, and the global star formation history of galaxies with observations does not allow us to disentangle the effects of the baryonic physics from those related to the different DM models. On the other hand, the distribution of the stellar-to-halo mass ratios, the abundance of faint galaxies in the UV luminosity function at z≳ 6, and the specific star formation and age distribution of local, low-mass galaxies constitute potential probes for the DM scenarios considered. We discuss how future observations with upcoming facilities will enable us to rule out or to strongly support DM models based on sterile neutrinos.

Neutrino physics

CERN Document Server

Hernandez, P.

2016-01-01

This is the writeup of the lectures on neutrino physics delivered at various schools: TASI and Trieste in 2013 and the CERN-Latin American School in 2015. The topics discussed in this lecture include: general properties of neutrinos in the SM, the theory of neutrino masses and mixings (Dirac and Majorana), neutrino oscillations both in vacuum and in matter, as well as an overview of the experimental evidence for neutrino masses and of the prospects in neutrino oscillation physics. We also briefly review the relevance of neutri- nos in leptogenesis and in beyond-the-Standard-Model physics.

Neutrino astrophysics

International Nuclear Information System (INIS)

Roulet, E.

2001-01-01

A general overview of neutrino physics and astrophysics is given, starting with a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and introduce the main scenarios to provide them a mass. The present bounds and the positive indications in favor of non-zero neutrino masses are discussed, including the recent results on atmospheric and solar neutrinos. The major role that neutrinos play in astrophysics and cosmology is illustrated. (author)

Neutrino oscillation study in the muon neutrino → electron neutrino channel at the Brookhaven accelerator

International Nuclear Information System (INIS)

Astier, P.

1987-09-01

The E816 experiment described in this thesis is devoted to a neutrino oscillation search at the Brookhaven AGS. The method used here is to look with a fine grained calorimeter for the appearence of electron neutrino in a muon neutrino beam. After recalling the theoretical treatment of the neutrino mass problem, the experimental phenomenology of massive neutrinos and more specifically neutrino oscillations is reviewed. The experiment itself is then extensively described, both on the technical side (detector, beam, simulation) and on the analysis side. In particular the statistical separation of the electromagnetic showers from electrons - our signal - and from photons - our background - treated in detail. The present analysis is based on 2/3 of the final statistics and it leads to the - preliminary - observation of an electron excess in the neutrino interactions yielding 19 ± 15.6 (stat) ± 7 (syst) [fr

Signatures of the neutrino mass hierarchy in supernova neutrinos

International Nuclear Information System (INIS)

Chiu, S.H.; Huang, Chu-Ching; Lai, Kwang-Chang

2015-01-01

The undetermined neutrino mass hierarchy may leave an observable imprint on the neutrino fluxes from a core-collapse supernova (SN). The interpretation of the observables, however, is subject to the uncertain SN models and the flavor conversion mechanism of neutrinos in a SN. We attempt to propose a qualitative interpretation of the expected neutrino events at terrestrial detectors, focusing on the accretion phase of the neutrino burst. The flavor conversions due to neutrino self-interaction, the MSW effect, and the Earth regeneration effect are incorporated in the calculation. It leads to several distinct scenarios that are identified by the neutrino mass hierarchies and the collective flavor transitions. Consequences resulting from the variation of incident angles and SN models are also discussed

Neutrino astronomy with supernova neutrinos

Science.gov (United States)

Brdar, Vedran; Lindner, Manfred; Xu, Xun-Jie

2018-04-01

Modern neutrino facilities will be able to detect a large number of neutrinos from the next Galactic supernova. We investigate the viability of the triangulation method to locate a core-collapse supernova by employing the neutrino arrival time differences at various detectors. We perform detailed numerical fits in order to determine the uncertainties of these time differences for the cases when the core collapses into a neutron star or a black hole. We provide a global picture by combining all the relevant current and future neutrino detectors. Our findings indicate that in the scenario of a neutron star formation, supernova can be located with precision of 1.5 and 3.5 degrees in declination and right ascension, respectively. For the black hole scenario, sub-degree precision can be reached.

A search for neutral, heavy particles decaying to a neutriNO1and a single photon at the SPS wide-band neutrino beam

CERN Document Server

Steele, D M

1996-01-01

A search is performed for single, isolated photons from X 0 decay, where X 0 represents either a neutrino excited state or an unknown, neutral, massive particle produced in a rare pi+ decay along the neutrino beam line as hypothesized by the KARMEN Collaboration[1] as a possible solution to their anomalous time spectra for pi+ -> u+ + vu. The analysis is performed using data from the NOMAD (WA96) experiment in the wide-band vu beam using the SPS accelerator situated at the European Center for Nuclear Research near Geneva, Switzerland. Out of a flux of vu resulting from 6.13 x 10*18 protons on target, seven events pass all cuts. The relative abundance of these events is entirely consistent with those expected from neutrino interactions in the detector. Upper limits are set at 90% condence level for the production rate of this particle as a function of its lifetime.

The solar neutrinos epopee; L'epopee des neutrinos solaires

Energy Technology Data Exchange (ETDEWEB)

Lasserre, Th. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules, de Physique Nucleaire et de l' Instrumentation Associee, Service de Physique des Particules, 91- Gif sur Yvette (France)

2003-06-01

The 2002 year has been fruitful for the neutrino physics. First, the Sudbury Neutrino Observatory (SNO) experiment has shown that the electron neutrinos {nu}{sub e} emitted by the sun are converted into muon neutrinos ({nu}{sub {mu}}) and tau neutrinos ({nu}{sub {tau}}), thus closing the 30 years old problem of solar neutrinos deficit. This discovery validates the model of nuclear energy production inside the sun but it shakes the theory describing the weak interactions between the fundamental constituents of matter. This theory considers the neutrinos (and the photons) as massless particles, while the taste conversion phenomenon necessarily implies that neutrinos have a mass. In October 2000, the Universe exploration by the cosmic neutrinos is jointly recognized by R. Davis (USA) and M. Koshiba (Japan) who received the Nobel price of physics. Finally, in December 2000, the KamLAND experiment quantitatively demonstrated the neutrinos metamorphosis by detecting a deficit in the flux of electron antineutrinos coming from the surrounding Japanese nuclear reactors. This digest article describes step by step the epopee of solar neutrinos and shows how several generations of physicists have resolved one of the mystery of modern physics. (J.S.)

Implications of the Mikheyev-Smirnov-Wolfenstein (MSW) mechanism of amplification of neutrino oscillations in matter

International Nuclear Information System (INIS)

Langacker, P.; Petcov, S.T.; Steigman, G.; Toshev, S.

1987-01-01

Mikheyev and Smirnov have recently proposed a novel and plausible solution of the solar neutrino problem, based on the resonant amplification of the neutrino oscillations in matter. We comment on several aspects of this mechanism. (i) For the values of neutrino masses and mixing angles predicted by the seesaw model of grand unified theories, the MSW effect may take place naturally in the Sun, leading to a considerable reduction of the flux of solar electron neutrinos, with the dominant transition being ν e →ν τ (rather than ν e →ν μ ). (ii) Oscillations between the ordinary neutrinos (ν e ,ν μ ,ν τ ) can affect primordial nucleosynthesis, but the effect is small (i.e., the abundance of 4 He is predicted to change by less than 1.3x10 -3 ). (iii) A comparison of some of the general properties of neutrino oscillations in matter and in vacuum is given. (orig.)

Supernova Neutrino-Process and Implication in Neutrino Oscillation

Science.gov (United States)

Kajino, T.; Aoki, W.; Fujiya, W.; Mathews, G. J.; Yoshida, T.; Shaku, K.; Nakamura, K.; Hayakawa, T.

2012-08-01

We studied the supernova nucleosynthesis induced by neutrino interactions and found that several isotopes of rare elements like 7Li, 11B, 138La, 180Ta and many others are predominantly produced by the neutrino-process in core-collapse supernovae. These isotopes are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect. We here propose a new novel method to determine the unknown neutrino oscillation parameters, θ13 and mass hierarchy simultaneously from the supernova neutrino-process, combined with the r-process for heavy-element synthsis and the Galactic chemical evolution on light nuclei.

Detecting Solar Neutrino Flare in Megaton and km3 detectors

International Nuclear Information System (INIS)

Fargion, Daniele; Di Giacomo, Paola

2009-01-01

To foresee a solar flare neutrino signal we infer its upper and lower bound. The upper bound was derived since a few years by general energy equipartition arguments on observed solar particle flare. The lower bound, the most compelling one for any guarantee neutrino signal, is derived by most recent records of hard Gamma bump due to solar flare on January 2005 (by neutral pion decay). Because neutral and charged pions (made by hadron scattering in the flare) are born on the same foot, their link is compelling: the observed gamma flux [Grechnev V.V. et al., (arXiv:0806.4424), Solar Physics, Vol. 1, October, (2008), 252] reflects into a corresponding one for the neutrinos, almost one to one. Moreover while gamma photons might be absorbed (in deep corona) or at least reduced inside the flaring plasma, the secondaries neutrino are not. So pion neutrinos should be even more abundant than gamma ones. Tens-hundred MeV neutrinos may cross undisturbed the whole Sun, doubling at least their rate respect a unique solar-side for gamma flare. Therefore we obtain minimal bounds opening a windows for neutrino astronomy, already at the edge of present but quite within near future Megaton neutrino detectors. Such detectors are considered mostly to reveal cosmic supernova background or rare Local Group (few Mpc) Supernovas events [Matthew D. Kistler et al. (0810.1959v1)]. However rarest (once a decade), brief (a few minutes) powerful solar neutrino 'flare' may shine and they may overcome by two to three order of magnitude the corresponding steady atmospheric neutrino noise on the Earth, leading in largest Neutrino detector at least to one or to meaning-full few events clustered signals. The voice of such a solar anti-neutrino flare component at a few tens MeVs may induce an inverse beta decay over a vanishing anti-neutrino solar background. Megaton or even inner ten Megaton Ice Cube detector at ten GeV threshold may also reveal traces in hardest energy of solar flares. Icecube

Early decay of Peccei–Quinn fermion and the IceCube neutrino events

Energy Technology Data Exchange (ETDEWEB)

Ema, Yohei, E-mail: ema@hep-th.phys.s.u-tokyo.ac.jp; Moroi, Takeo

2016-11-10

IceCube observed high-energy neutrino flux in the energy region from TeV to PeV. The decay of a massive long-lived particle in the early universe can be the origin of the IceCube neutrino events, which we call an “early decay scenario.” In this paper, we construct a particle physics model that contains such a massive long-lived particle based on the Peccei–Quinn model. We calculate the present neutrino flux, taking account of realistic initial energy distributions of particles produced by the decay of the massive long-lived particle. We show that the early decay scenario naturally fits into the Peccei–Quinn model, and that the neutrino flux observed by IceCube can be explained in such a framework. We also see that, based on that model, a consistent cosmological history that explains the abundance of the massive long-lived particle is realized.

Neutrino observations from the Sudbury Neutrino Observatory

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Q.R.; Allen, R.C.; Andersen, T.C.; Anglin, J.D.; Barton,J.C.; Beier, E.W.; Bercovitch, M.; Bigu, J.; Biller, S.D.; Black, R.A.; Blevis, I.; Boardman, R.J.; Boger, J.; Bonvin, E.; Boulay, M.G.; Bowler,M.G.; Bowles, T.J.; Brice, S.J.; Browne, M.C.; Bullard, T.V.; Buhler, G.; Cameron, J.; Chan, Y.D.; Chen, H.H.; Chen, M.; Chen, X.; Cleveland, B.T.; Clifford, E.T.H.; Cowan, J.H.M.; Cowen, D.F.; Cox, G.A.; Dai, X.; Dalnoki-Veress, F.; Davidson, W.F.; Doe, P.J.; Doucas, G.; Dragowsky,M.R.; Duba, C.A.; Duncan, F.A.; Dunford, M.; Dunmore, J.A.; Earle, E.D.; Elliott, S.R.; Evans, H.C.; Ewan, G.T.; Farine, J.; Fergani, H.; Ferraris, A.P.; Ford, R.J.; Formaggio, J.A.; Fowler, M.M.; Frame, K.; Frank, E.D.; Frati, W.; Gagnon, N.; Germani, J.V.; Gil, S.; Graham, K.; Grant, D.R.; Hahn, R.L.; Hallin, A.L.; Hallman, E.D.; Hamer, A.S.; Hamian, A.A.; Handler, W.B.; Haq, R.U.; Hargrove, C.K.; Harvey, P.J.; Hazama, R.; Heeger, K.M.; Heintzelman, W.J.; Heise, J.; Helmer, R.L.; Hepburn, J.D.; Heron, H.; Hewett, J.; Hime, A.; Hykawy, J.G.; Isaac,M.C.P.; Jagam, P.; Jelley, N.A.; Jillings, C.; Jonkmans, G.; Kazkaz, K.; Keener, P.T.; Klein, J.R.; Knox, A.B.; Komar, R.J.; Kouzes, R.; Kutter,T.; Kyba, C.C.M.; Law, J.; Lawson, I.T.; Lay, M.; Lee, H.W.; Lesko, K.T.; Leslie, J.R.; Levine, I.; Locke, W.; Luoma, S.; Lyon, J.; Majerus, S.; Mak, H.B.; Maneira, J.; Manor, J.; Marino, A.D.; McCauley, N.; McDonald,D.S.; McDonald, A.B.; McFarlane, K.; McGregor, G.; Meijer, R.; Mifflin,C.; Miller, G.G.; Milton, G.; Moffat, B.A.; Moorhead, M.; Nally, C.W.; Neubauer, M.S.; Newcomer, F.M.; Ng, H.S.; Noble, A.J.; Norman, E.B.; Novikov, V.M.; O' Neill, M.; Okada, C.E.; Ollerhead, R.W.; Omori, M.; Orrell, J.L.; Oser, S.M.; Poon, A.W.P.; Radcliffe, T.J.; Roberge, A.; Robertson, B.C.; Robertson, R.G.H.; Rosendahl, S.S.E.; Rowley, J.K.; Rusu, V.L.; Saettler, E.; Schaffer, K.K.; Schwendener,M.H.; Schulke, A.; Seifert, H.; Shatkay, M.; Simpson, J.J.; Sims, C.J.; et al.

2001-09-24

The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D{sub 2}O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar {nu}{sub e} flux and the total flux of all active neutrino species. Solar neutrinos from the decay of {sup 8}B have been detected at SNO by the charged-current (CC) interaction on the deuteron and by the elastic scattering (ES) of electrons. While the CC reaction is sensitive exclusively to {nu}{sub e}, the ES reaction also has a small sensitivity to {nu}{sub {mu}} and {nu}{sub {tau}}. In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from {sup 8}B decay as measured from the ES reaction rate under the no-oscillation assumption is consistent with the high precision ES measurement by the Super-Kamiokande experiment. The {nu}{sub e} flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3{sigma}. This is evidence for an active neutrino component, in additional to {nu}{sub e}, in the solar neutrino flux. These results also allow the first experimental determination of the total active {sup 8}B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions.

Neutrino Observations from the Sudbury Neutrino Observatory

Science.gov (United States)

Q. R. Ahmad, R. C. Allen, T. C. Andersen, J. D. Anglin, G. B?hler, J. C. Barton, E. W. Beier, M. Bercovitch, J. Bigu, S. Biller, R. A. Black, I. Blevis, R. J. Boardman, J. Boger, E. Bonvin, M. G. Boulay, M. G. Bowler, T. J. Bowles, S. J. Brice, M. C. Browne, T. V. Bullard, T. H. Burritt, K. Cameron, J. Cameron, Y. D. Chan, M. Chen, H. H. Chen, X. Chen, M. C. Chon, B. T. Cleveland, E. T. H. Clifford, J. H. M. Cowan, D. F. Cowen, G. A. Cox, Y. Dai, X. Dai, F. Dalnoki-Veress, W. F. Davidson, P. J. Doe, G. Doucas, M. R. Dragowsky, C. A. Duba, F. A. Duncan, J. Dunmore, E. D. Earle, S. R. Elliott, H. C. Evans, G. T. Ewan, J. Farine, H. Fergani, A. P. Ferraris, R. J. Ford, M. M. Fowler, K. Frame, E. D. Frank, W. Frati, J. V. Germani, S. Gil, A. Goldschmidt, D. R. Grant, R. L. Hahn, A. L. Hallin, E. D. Hallman, A. Hamer, A. A. Hamian, R. U. Haq, C. K. Hargrove, P. J. Harvey, R. Hazama, R. Heaton, K. M. Heeger, W. J. Heintzelman, J. Heise, R. L. Helmer, J. D. Hepburn, H. Heron, J. Hewett, A. Hime, M. Howe, J. G. Hykawy, M. C. P. Isaac, P. Jagam, N. A. Jelley, C. Jillings, G. Jonkmans, J. Karn, P. T. Keener, K. Kirch, J. R. Klein, A. B. Knox, R. J. Komar, R. Kouzes, T. Kutter, C. C. M. Kyba, J. Law, I. T. Lawson, M. Lay, H. W. Lee, K. T. Lesko, J. R. Leslie, I. Levine, W. Locke, M. M. Lowry, S. Luoma, J. Lyon, S. Majerus, H. B. Mak, A. D. Marino, N. McCauley, A. B. McDonald, D. S. McDonald, K. McFarlane, G. McGregor, W. McLatchie, R. Meijer Drees, H. Mes, C. Mifflin, G. G. Miller, G. Milton, B. A. Moffat, M. Moorhead, C. W. Nally, M. S. Neubauer, F. M. Newcomer, H. S. Ng, A. J. Noble, E. B. Norman, V. M. Novikov, M. O'Neill, C. E. Okada, R. W. Ollerhead, M. Omori, J. L. Orrell, S. M. Oser, A. W. P. Poon, T. J. Radcliffe, A. Roberge, B. C. Robertson, R. G. H. Robertson, J. K. Rowley, V. L. Rusu, E. Saettler, K. K. Schaffer, A. Schuelke, M. H. Schwendener, H. Seifert, M. Shatkay, J. J. Simpson, D. Sinclair, P. Skensved, A. R. Smith, M. W. E. Smith, N. Starinsky, T. D. Steiger, R. G. Stokstad, R. S. Storey, B. Sur, R. Tafirout, N. Tagg, N. W. Tanner, R. K. Taplin, M. Thorman, P. Thornewell, P. T. Trent, Y. I. Tserkovnyak, R. Van Berg, R. G. Van de Water, C. J. Virtue, C. E. Waltham, J.-X. Wang, D. L. Wark, N. West, J. B. Wilhelmy, J. F. Wilkerson, J. Wilson, P. Wittich, J. M. Wouters, and M. Yeh

2001-09-24

The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D{sub 2}O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar {nu}{sub e} flux and the total flux of all active neutrino species. Solar neutrinos from the decay of {sup 8}B have been detected at SNO by the charged-current (CC) interaction on the deuteron and by the elastic scattering (ES) of electrons. While the CC reaction is sensitive exclusively to {nu}{sub e}, the ES reaction also has a small sensitivity to {nu}{sub {mu}} and {nu}{sub {tau}}. In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from {sup 8}B decay as measured from the ES reaction rate under the no-oscillation assumption is consistent with the high precision ES measurement by the Super-Kamiokande experiment. The {nu}{sub e} flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3{sigma}. This is evidence for an active neutrino component, in additional to {nu}{sub e}, in the solar neutrino flux. These results also allow the first experimental determination of the total active {sup 8}B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions.

Testing the Big Bang: Light elements, neutrinos, dark matter and large-scale structure

Science.gov (United States)

Schramm, David N.

1991-01-01

Several experimental and observational tests of the standard cosmological model are examined. In particular, a detailed discussion is presented regarding: (1) nucleosynthesis, the light element abundances, and neutrino counting; (2) the dark matter problems; and (3) the formation of galaxies and large-scale structure. Comments are made on the possible implications of the recent solar neutrino experimental results for cosmology. An appendix briefly discusses the 17 keV thing and the cosmological and astrophysical constraints on it.

Supernova neutrino detection

International Nuclear Information System (INIS)

Selvi, M.

2005-01-01

Neutrinos emitted during a supernova core collapse represent a unique feature to study both stellar and neutrino properties. After discussing the details of the neutrino emission in the star and the effect of neutrino oscillations on the expected neutrino fluxes at Earth, a review of the detection techniques is presented in this paper, with particular attention to the problem of electron neutrino detection

Non-unitary neutrino propagation from neutrino decay

Energy Technology Data Exchange (ETDEWEB)

Berryman, Jeffrey M., E-mail: jeffreyberryman2012@u.northwestern.edu [Northwestern University, Department of Physics & Astronomy, 2145 Sheridan Road, Evanston, IL 60208 (United States); Gouvêa, André de; Hernández, Daniel [Northwestern University, Department of Physics & Astronomy, 2145 Sheridan Road, Evanston, IL 60208 (United States); Oliveira, Roberto L.N. [Northwestern University, Department of Physics & Astronomy, 2145 Sheridan Road, Evanston, IL 60208 (United States); Instituto de Física Gleb Wataghin Universidade Estadual de Campinas, UNICAMP 13083-970, Campinas, São Paulo (Brazil)

2015-03-06

Neutrino propagation in space-time is not constrained to be unitary if very light states – lighter than the active neutrinos – exist into which neutrinos may decay. If this is the case, neutrino flavor-change is governed by a handful of extra mixing and “oscillation” parameters, including new sources of CP-invariance violation. We compute the transition probabilities in the two- and three-flavor scenarios and discuss the different phenomenological consequences of the new physics. These are qualitatively different from other sources of unitarity violation discussed in the literature.

Non-unitary neutrino propagation from neutrino decay

International Nuclear Information System (INIS)

Berryman, Jeffrey M.; Gouvêa, André de; Hernández, Daniel; Oliveira, Roberto L.N.

2015-01-01

Neutrino propagation in space-time is not constrained to be unitary if very light states – lighter than the active neutrinos – exist into which neutrinos may decay. If this is the case, neutrino flavor-change is governed by a handful of extra mixing and “oscillation” parameters, including new sources of CP-invariance violation. We compute the transition probabilities in the two- and three-flavor scenarios and discuss the different phenomenological consequences of the new physics. These are qualitatively different from other sources of unitarity violation discussed in the literature

A Virtual Reconstruction Methodology for Archaeological Heritage in East Asia – Practical Experience from the Re-relic Program in China

Directory of Open Access Journals (Sweden)

Yan He

2013-11-01

Full Text Available There is as much abundance of archaeological heritage in East Asia as there is diversity in the methodology for its reconstruction and representation. The Re-relic program in China recognizes the uniqueness of archaeological heritage in East Asia and has developed a tailored virtual reconstruction methodology that is both scientifically robust and popular for public interpretation. The theoretical consideration and field experience over the years shall contribute to the global understanding of the value and technique in virtual reconstruction, while testifying to the very principles of Seville Charter.

Z-burst scenario for the highest energy cosmic rays

International Nuclear Information System (INIS)

Fodor, Z.

2002-10-01

The origin of highest energy cosmic rays is yet unknown. An appealing possibility is the so-called Z-burst scenario, in which a large fraction of these cosmic rays are decay products of Z bosons produced in the scattering of ultrahigh energy neutrinos on cosmological relic neutrinos. The comparison between the observed and predicted spectra constrains the mass of the heaviest neutrino. The required neutrino mass is fairly robust against variations of the presently unknown quantities, such as the amount of relic neutrino clustering, the universal photon radio background and the extragalactic magnetic field. Considering different possibilities for the ordinary cosmic rays the required neutrino masses are determined. In the most plausible case that the ordinary cosmic rays are of extragalactic origin and the universal radio background is strong enough to suppress high energy photons, the required neutrino mass is 0.08 eV ≤ m ν ≤ 0.40 eV. The required ultrahigh energy neutrino flux should be detected in the near future by experiments such as AMANDA, RICE or the Pierre Auger Observatory. (orig.)

GENIUS Project, Neutrino Oscillations and Cosmology: Neutrinos Reveal Their Nature ?

International Nuclear Information System (INIS)

Czakon, M.; Studnik, J.; Zralek, M.; Gluza, J.

2000-01-01

The neutrinoless double beta decay as well as any other laboratory experiment has not been able to answer the question of the neutrino's nature. Hints on the answer are available when neutrino oscillations and (ββ) 0ν are considered simultaneously. In this case phenomenologically interesting neutrino mass schemes can lead to non-vanishing and large values of (m ν ). As a consequence, some schemes with Majorana neutrinos can be ruled out even now. If we assume that in addition neutrinos contribute to Hot Dark Matter then the window for Majorana neutrinos is even more restricted, e.g. GENIUS experiment will be sensitive to scenarios with three Majorana neutrinos. (author)

arXiv Squeezed relic photons beyond the horizon

CERN Document Server

Giovannini, Massimo

2017-11-14

Owing to the analogy with the ordinary photons in the visible range of the electromagnetic spectrum, the Glauber theory is generalized to address the quantum coherence of the gauge field fluctuations parametrically amplified during an inflationary stage of expansion. The first and second degrees of quantum coherence of relic photons are then computed beyond the effective horizon defined by the evolution of the susceptibility. In the zero-delay limit the Hanbury Brown-Twiss correlations exhibit a super-Poissonian statistics which is however different from the conventional results of the single-mode approximation customarily employed, in quantum optics, to classify the coherence properties of visible light. While in the case of large-scale curvature perturbations the degrees of quantum coherence coincide with the naive expectation of the single-mode approximation, the net degree of second-order coherence computed for the relic photons diminishes thanks to the effect of the polarizations. We suggest that the Han...

Finger of a saint, thumb of a priest: medieval relics in the Diocese of Turku, and the archaeology of lived bodies

Directory of Open Access Journals (Sweden)

Visa Immonen

2011-01-01

Full Text Available The relics of Turku Cathedral are remains belonging to the bodies of holy persons, different from ours, even today, although the cathedral is the see for the archbishop of the Evangelical Lutheran Church of Finland, and relics are not on public display. Among the relics of the cathedral, there is a fragment of a radius, which according to its authentica, belongs to St Henry. Relics and reliquaries were in the core of medieval piety, and the cult of saints had infused throughout the society. Due to their central position in culture, relics offer glimpses at a range of material, social and cultural phenomena related to medieval embodiment.The Department of Archaeology at the University of Turku began to study the finger relic of St Eric and other items in the assemblage of Turku Cathedral in 2007. Relics and reliquaries are being opened and documented and organic as well as inorganic samples are being taken for a range of scientific analyses. So far the project has concentrated on building a chronological chart of individual artefacts. The majority of the relics date to the fourteenth century, although much more recent datings have also been obtained. The challenge of the project is not to stop when a better understanding of materials, their origins and age has been accomplished, but to use the results as a steppingstone into a study of the practices of medieval relic veneration. Medieval bodies and those material processes which authenticate relics, or distinguish saints’ bodies from other human remains, are thus at the heart of this article discussing embodiment.

Sterile neutrino

International Nuclear Information System (INIS)

Anon.

2007-01-01

Paper deals with the information on the occurrence of the fields of the sterile neutrinos (the righthanded ones) mixed with the normal neutrinos (the lefthanded ones). Both the Max Plank Radioastronomy Institute and the Los Angeles University assumes that the occurrence of the keV mass sterile neutrinos may explain the dark matter nature, the fast rotation of the observed pulsars and the reionization processes. The issues associated with the possibility to record the sterile neutrinos were analyzed in the course of the Sterile Neutrinos in Astrophysics and Cosmology Workshop (Crans Montana, March 2006 [ru

Feasibility of 81Br(nu,e-)81Kr solar neutrino experiment

International Nuclear Information System (INIS)

Hurst, G.S.; Allman, S.L.; Chen, C.H.; Kramer, S.D.; Thomson, J.O.; Cleveland, B.

1985-05-01

Several ingenious solutions have been offered for the solar neutrino problem - a defect in the solar model, the appearance of a new type of neutrino physics, the sun is no longer burning, etc. The range of these proffered solutions stresses the need for a new experiment to study the sun. The modern pulsed laser now makes possible a new solar neutrino test which examines an independent neutrino source in the sun. A recently proposed experiment would use the reaction 81 Br(nu,e - ) 81 Kr to measure the flux of 7 Be neutrinos from the sun. When 7 Be decays by electron capture to make 7 Li, a neutrino is emitted at 0.862 MeV and the flux of these on the earth is about 4 x 10 9 cm -2 s -1 , according to the standard model. Therefore, an experiment based on 81 Br(nu,e - ) 81 Kr which is sensitive to these lower energy neutrinos would be of fundamental importance. To first order, the chlorine experiment detects the 8 B neutrinos while bromine detects the much more abundant 7 Be neutrino source. In practice, the proposed bromine experiment would be very similar to the chlorine radiochemical experiment, except that 81 Kr with a half-life of 2 x 10 5 years cannot be counted by decay methods. With an experiment of about the same volume as the chlorine experiment (380 m 3 ) filled with CH 2 Br 2 , the model predicts about 2 atoms of 81 Kr per day. The bromine experiment depends entirely on the RIS method, implemented with pulsed lasers, for its success. 10 refs., 3 figs

Neutrinos and Einstein

CERN Document Server

Suzuki, Yoichiro

2005-01-01

A tiny neutrino mass is a clue to the physics beyond the standard model of elementary particle physics. The primary cosmic rays, mostly protons, are created and accelerated to the relativistic energy in supernova remnants. They traverse the universe and reach the earth. The incoming primary cosmic rays interact with the earth's atmosphere to produce secondary particles, which subsequently decay into neutrinos, called atmospheric neutrinos. The atmospheric neutrinos have shown the evidence of the finite neutrino masses through the phenomena called neutrino oscillations. Neutrinos are detected by large detectors underground like, for example, Super-Kamiokande, SNO and KamLAND. Those detectors use large photomultiplier tubes, which make use of the photo-electric effect to convert photons created by the interaction of neutrinos to electrons to form electric pulses. Neutrinos are therefore created and detected by "Einstein" and have step forward beyond the current physics. Neutrinos may also carry a hit to the ori...

(N)LSP decays and gravitino dark matter relic abundance in big divisor (nearly) SLagy D3/D7μ-split SUSY

Science.gov (United States)

Dhuria, Mansi; Misra, Aalok

2013-02-01

Using the (nearly) Ricci-flat Swiss-Cheese metric of Misra (2012) [1], in the context of a mobile space-time filling D3-brane restricted to a nearly special Lagrangian sub-manifold (in the large volume limit, the pull-back of the Kähler form close to zero and the real part of the pull-back of e, θ=π/2 times the nowhere-vanishing holomorphic three-form providing the volume form on the three-cycle) of the "big" divisor with (fluxed stacks of) space-time filling D7-branes also wrapping the "big" divisor (corresponding to a local minimum), we provide an explicit identification of the electron and the u-quark, as well as their SU (2-singlet cousins, with fermionic superpartners of four Wilson line moduli; their superpartners turn out to be very heavy, the Higgsino-mass parameter turns out to be large, one obtains one light (with a mass of 125 GeV) and one heavy Higgs and the gluino is long lived (from a collider point of view) providing a possible realization of "μ-Split Supersymmetry". By explicitly calculating the lifetimes of decays of the co-NLSPs - the first generation squark/slepton and a neutralino - to the LSP - the gravitino - as well as gravitino decays, we verify that BBN constraints relevant to the former as well as the requirement of the latter to be (more than) the age of the universe, are satisfied. For the purpose of calculation of the gravitino relic density in terms of the neutralino/slepton relic density, we evaluate the latter by evaluating the neutralino/slepton (co-)annihilation cross sections and hence show that the former satisfies the requirement for a dark matter candidate.

(N)LSP decays and gravitino dark matter relic abundance in big divisor (nearly) SLagy D3/D7μ-split SUSY

International Nuclear Information System (INIS)

Dhuria, Mansi; Misra, Aalok

2013-01-01

Using the (nearly) Ricci-flat Swiss-Cheese metric of Misra (2012) [1], in the context of a mobile space–time filling D3-brane restricted to a nearly special Lagrangian sub-manifold (in the large volume limit, the pull-back of the Kähler form close to zero and the real part of the pull-back of e −iθ , θ=(π)/2 times the nowhere-vanishing holomorphic three-form providing the volume form on the three-cycle) of the “big” divisor with (fluxed stacks of) space–time filling D7-branes also wrapping the “big” divisor (corresponding to a local minimum), we provide an explicit identification of the electron and the u-quark, as well as their SU(2) L -singlet cousins, with fermionic superpartners of four Wilson line moduli; their superpartners turn out to be very heavy, the Higgsino-mass parameter turns out to be large, one obtains one light (with a mass of 125 GeV) and one heavy Higgs and the gluino is long lived (from a collider point of view) providing a possible realization of “μ-Split Supersymmetry”. By explicitly calculating the lifetimes of decays of the co-NLSPs – the first generation squark/slepton and a neutralino – to the LSP – the gravitino – as well as gravitino decays, we verify that BBN constraints relevant to the former as well as the requirement of the latter to be (more than) the age of the universe, are satisfied. For the purpose of calculation of the gravitino relic density in terms of the neutralino/slepton relic density, we evaluate the latter by evaluating the neutralino/slepton (co-)annihilation cross sections and hence show that the former satisfies the requirement for a dark matter candidate.

(N)LSP decays and gravitino dark matter relic abundance in big divisor (nearly) SLagy D3/D7{mu}-split SUSY

Energy Technology Data Exchange (ETDEWEB)

Dhuria, Mansi, E-mail: mansidph@iitr.ernet.in [Department of Physics, Indian Institute of Technology, Roorkee 247 667, Uttaranchal (India); Misra, Aalok, E-mail: aalokfph@iitr.ernet.in [Department of Physics, Indian Institute of Technology, Roorkee 247 667, Uttaranchal (India)

2013-02-21

Using the (nearly) Ricci-flat Swiss-Cheese metric of Misra (2012) [1], in the context of a mobile space-time filling D3-brane restricted to a nearly special Lagrangian sub-manifold (in the large volume limit, the pull-back of the Kaehler form close to zero and the real part of the pull-back of e{sup -i{theta}}, {theta}=({pi})/2 times the nowhere-vanishing holomorphic three-form providing the volume form on the three-cycle) of the 'big' divisor with (fluxed stacks of) space-time filling D7-branes also wrapping the 'big' divisor (corresponding to a local minimum), we provide an explicit identification of the electron and the u-quark, as well as their SU(2){sub L}-singlet cousins, with fermionic superpartners of four Wilson line moduli; their superpartners turn out to be very heavy, the Higgsino-mass parameter turns out to be large, one obtains one light (with a mass of 125 GeV) and one heavy Higgs and the gluino is long lived (from a collider point of view) providing a possible realization of '{mu}-Split Supersymmetry'. By explicitly calculating the lifetimes of decays of the co-NLSPs - the first generation squark/slepton and a neutralino - to the LSP - the gravitino - as well as gravitino decays, we verify that BBN constraints relevant to the former as well as the requirement of the latter to be (more than) the age of the universe, are satisfied. For the purpose of calculation of the gravitino relic density in terms of the neutralino/slepton relic density, we evaluate the latter by evaluating the neutralino/slepton (co-)annihilation cross sections and hence show that the former satisfies the requirement for a dark matter candidate.

Matter-neutrino resonance in a multiangle neutrino bulb model

Science.gov (United States)

Vlasenko, Alexey; McLaughlin, G. C.

2018-04-01

Simulations of neutrino flavor evolution in compact merger environments have shown that neutrino flavor, and hence nucleosynthesis, can be strongly affected by the presence of matter-neutrino resonances (MNRs), where there is a cancelation between the matter and the neutrino potential. Simulations performed thus far follow flavor evolution along a single neutrino trajectory, but self-consistency requires all trajectories to be treated simultaneously, and it has not been known whether MNR phenomena would still occur in multiangle models. In this paper, we present the first fully multi-angle calculations of MNR. We find that familiar MNR phenomena, where neutrinos transform to a greater extent than anti-neutrinos and a feedback mechanism maintains the cancellation between the matter and neutrino potential, still occurs for a subset of angular bins, although the flavor transformation is not as efficient as in the single-angle case. In addition, we find other types of flavor transformation that are not seen in single-angle simulations. These flavor transformation phenomena appear to be robust and are present for a wide range of model parameters, as long as an MNR is present. Although computational constraints currently limit us to models with spherical symmetry, our results suggest that the presence of an MNR generally leads to large-scale neutrino flavor evolution in multiangle systems.

Neutrino Factory

CERN Document Server

Bogomilov, M; Tsenov, R; Dracos, M; Bonesini, M; Palladino, V; Tortora, L; Mori, Y; Planche, T; Lagrange, J  B; Kuno, Y; Benedetto, E; Efthymiopoulos, I; Garoby, R; Gilardoini, S; Martini, M; Wildner, E; Prior, G; Blondel, A; Karadzhow, Y; Ellis, M; Kyberd, P; Bayes, R; Laing, A; Soler, F  J  P; Alekou, A; Apollonio, M; Aslaninejad, M; Bontoiu, C; Jenner, L  J; Kurup, A; Long, K; Pasternak, J; Zarrebini, A; Poslimski, J; Blackmore, V; Cobb, J; Tunnell, C; Andreopoulos, C; Bennett, J  R  J; Brooks, S; Caretta, O; Davenne, T; Densham, C; Edgecock, T  R; Fitton, M; Kelliher, D; Loveridge, P; McFarland, A; Machida, S; Prior, C; Rees, G; Rogers, C; Rooney, M; Thomason, J; Wilcox, D; Booth, C; Skoro, G; Back, J  J; Harrison, P; Berg, J  S; Fernow, R; Gallardo, J  C; Gupta, R; Kirk, H; Simos, N; Stratakis, D; Souchlas, N; Witte, H; Bross, A; Geer, S; Johnstone, C; Mokhov, N; Neuffer, D; Popovic, M; Strait, J; Striganov, S; Morfín, J  G; Wands, R; Snopok, P; Bogacz, S  A; Morozov, V; Roblin, Y; Cline, D; Ding, X; Bromberg, C; Hart, T; Abrams, R  J; Ankenbrandt, C  M; Beard, K  B; Cummings, M  A  C; Flanagan, G; Johnson, R  P; Roberts, T  J; Yoshikawa, C  Y; Graves, V  B; McDonald, K  T; Coney, L; Hanson, G

2014-01-01

The properties of the neutrino provide a unique window on physics beyond that described by the standard model. The study of subleading effects in neutrino oscillations, and the race to discover CP-invariance violation in the lepton sector, has begun with the recent discovery that $\\theta_{13} > 0$. The measured value of $\\theta_{13}$ is large, emphasizing the need for a facility at which the systematic uncertainties can be reduced to the percent level. The neutrino factory, in which intense neutrino beams are produced from the decay of muons, has been shown to outperform all realistic alternatives and to be capable of making measurements of the requisite precision. Its unique discovery potential arises from the fact that only at the neutrino factory is it practical to produce high-energy electron (anti)neutrino beams of the required intensity. This paper presents the conceptual design of the neutrino factory accelerator facility developed by the European Commission Framework Programme 7 EURO$\

The B-L phase transition. Implications for cosmology and neutrinos

International Nuclear Information System (INIS)

Schmitz, Kai

2012-07-01

We investigate the possibility that the hot thermal phase of the early universe is ignited in consequence of the B-L phase transition, which represents the cosmological realization of the spontaneous breaking of the Abelian gauge symmetry associated with B-L, the difference between baryon number B and lepton number L. Prior to the B-L phase transition, the universe experiences a stage of hybrid inflation. Towards the end of inflation, the false vacuum of unbroken B-L symmetry decays, which entails tachyonic preheating as well as the production of cosmic strings. Observational constraints on this scenario require the B-L phase transition to take place at the scale of grand unification. The dynamics of the B-L breaking Higgs field and the B-L gauge degrees of freedom, in combination with thermal processes, generate an abundance of heavy (s)neutrinos. These (s)neutrinos decay into radiation, thereby reheating the universe, generating the baryon asymmetry of the universe and setting the stage for the thermal production of gravitinos. The B-L phase transition along with the (s)neutrino-driven reheating process hence represents an intriguing and testable mechanism to generate the initial conditions of the hot early universe. We study the B-L phase transition in the full supersymmetric Abelian Higgs model, for which we derive and discuss the Lagrangian in arbitrary and unitary gauge. As for the subsequent reheating process, we formulate the complete set of Boltzmann equations, the solutions of which enable us to give a detailed and time-resolved description of the evolution of all particle abundances during reheating. Assuming the gravitino to be the lightest superparticle (LSP), the requirement of consistency between hybrid inflation, leptogenesis and gravitino dark matter implies relations between neutrino parameters and superparticle masses, in particular a lower bound on the gravitino mass of 10GeV. As an alternative to gravitino dark matter, we consider the case of

The B-L phase transition. Implications for cosmology and neutrinos

Energy Technology Data Exchange (ETDEWEB)

Schmitz, Kai

2012-07-15

We investigate the possibility that the hot thermal phase of the early universe is ignited in consequence of the B-L phase transition, which represents the cosmological realization of the spontaneous breaking of the Abelian gauge symmetry associated with B-L, the difference between baryon number B and lepton number L. Prior to the B-L phase transition, the universe experiences a stage of hybrid inflation. Towards the end of inflation, the false vacuum of unbroken B-L symmetry decays, which entails tachyonic preheating as well as the production of cosmic strings. Observational constraints on this scenario require the B-L phase transition to take place at the scale of grand unification. The dynamics of the B-L breaking Higgs field and the B-L gauge degrees of freedom, in combination with thermal processes, generate an abundance of heavy (s)neutrinos. These (s)neutrinos decay into radiation, thereby reheating the universe, generating the baryon asymmetry of the universe and setting the stage for the thermal production of gravitinos. The B-L phase transition along with the (s)neutrino-driven reheating process hence represents an intriguing and testable mechanism to generate the initial conditions of the hot early universe. We study the B-L phase transition in the full supersymmetric Abelian Higgs model, for which we derive and discuss the Lagrangian in arbitrary and unitary gauge. As for the subsequent reheating process, we formulate the complete set of Boltzmann equations, the solutions of which enable us to give a detailed and time-resolved description of the evolution of all particle abundances during reheating. Assuming the gravitino to be the lightest superparticle (LSP), the requirement of consistency between hybrid inflation, leptogenesis and gravitino dark matter implies relations between neutrino parameters and superparticle masses, in particular a lower bound on the gravitino mass of 10GeV. As an alternative to gravitino dark matter, we consider the case of

Majorana mass term, Dirac neutrinos and selective neutrino oscillations

International Nuclear Information System (INIS)

Leung, C.N.

1987-01-01

In a theory of neutrino mixing via a Majorana mass term involving only the left-handed neutrinos there exist selection rules for neutrino oscillations if true Dirac and/or exactly zero mass eigenstates are present. In the case of three neutrino flavours no oscillation is allowed if the mass spectrum contains one Dirac and one nondegenerate Majorana massive neutrino. The origin of these selection rules and their implications are discussed and the number of possible CP-violating phases in the lepton mixing matrix when Dirac and Majorana mass eigenstates coexist is given. (orig.)

Eclipsed neutrinos

International Nuclear Information System (INIS)

Anon.

1995-01-01

Full text: The total solar eclipse visible in Southern Asia on 24 October provided an opportunity for an unusual physics experiment. At face value, the levels of solar neutrinos detected on the Earth's surface are difficult to understand and suggest that perhaps the composition of solar neutrinos oscillates between different neutrino types on their journey. In this way neutrinos originating in the Sun as electrontype could convert into heavy neutrinos, which could subsequently disintegrate into an electron-neutrino and a photon. In certain neutrino scenarios, such a photon would have an energy corresponding to that of visible light, and in principle should be detectable if there are enough of them. The problem is that they would normally be swamped by the copious photons of sunlight. The 24 October solar eclipse provided a chance to check this out. A team led by François Vannucci, spokesman of the Nomad neutrino experiment at CERN, en route to the 'Rencontres du Vietnam' physics meeting in Ho Chi Minh Ville, set up a CCD-equipped telescope. To insure against cloud cover, a second telescope followed the eclipse in the desert of Rajastan, India, where the eclipse was to last only half as long, but the chance of cloud was minimal. No background solar signal was seen, or, expressed in physics terms, if solar radiation has any heavy neutrino component, then less than a millionth of it disintegrates into an electron neutrino and a visible photon before it arrives at the Earth. The negative result also has implications for candidate massive, unstable neutrinos from other sources, notably a component of the missing 'dark matter' of the Universe. The next such eclipse should be visible in North Asia in 1997, when hopefully better measurements will be made

Complementarity of DM Searches in a Consistent Simplified Model: the Case of Z'

CERN Document Server

Jacques, Thomas; Morgante, Enrico; Racco, Davide; Rameez, Mohamed; Riotto, Antonio

2016-01-01

We analyze the constraints from direct and indirect detection on fermionic Majorana Dark Matter (DM). Because the interaction with the Standard Model (SM) particles is spin-dependent, a priori the constraints that one gets from neutrino telescopes, the LHC and direct detection experiments are comparable. We study the complementarity of these searches in a particular example, in which a heavy $Z'$ mediates the interactions between the SM and the DM. We find that in most cases IceCube provides the strongest bounds on this scenario, while the LHC constraints are only meaningful for smaller dark matter masses. These light masses are less motivated by thermal relic abundance considerations. We show that the dominant annihilation channels of the light DM in the Sun are either $b \\bar b$ or $t \\bar t$, while the heavy DM annihilation is completely dominated by $Zh$ channel. The latter produces a hard neutrino spectrum which has not been previously analyzed. We study the neutrino spectrum yielded by DM and recast Ice...

Radiative corrections for the direct detection of neutralino dark matter and its relic density

Energy Technology Data Exchange (ETDEWEB)

Steppeler, Patrick Norbert

2016-07-01

entering the Boltzmann equation in many scenarios of the MSSM. The Boltzmann equation allows to determine the neutralino relic density, i.e. to predict their present abundance. This prediction can be checked experimentally and is thus of great phenomenological relevance. Measurements of the temperature fluctuations of the cosmic microwave background permit to determine the relic density precisely. Comparing the theoretical prediction with the experimental finding allows to exclude large fractions of the MSSM parameter space. In order to maximally benefit from the experimental precision, it is necessary to minimise theoretical uncertainties and to include the aforementioned radiative corrections. The radiative corrections to the elastic neutralino-nucleon scattering and the corresponding relic density have been implemented into the numerical package Dark matter at next-to-leading order. With the help of this program, we perform a phenomenological investigation and analyse the impact of the radiative corrections. It turns out that the neutralino relic density depends not on a single but a multitude of gaugino (co)annihilation processes in parallel quite often. The calculated radiative corrections lead to a relative shift of the relic density of up to 10%, which is significantly larger than the experimental uncertainty (±2% at the 1σ confidence level) and demonstrates that these corrections should be included when identifying the cosmologically preferred region of the MSSM. Moreover, we investigate the relation between the relic density and the neutralino-nucleon cross sections. In the spin-independent case, the inclusion of radiative corrections leads to a relative shift roughly +14% in comparison to a tree-level calculation. This shift is comparable to typical recent nuclear uncertainties, which influence the prediction as well. The spin-dependent cross section is subject to even larger shifts and modified by up to -50% by radiative corrections.

Solar neutrinos

International Nuclear Information System (INIS)

Phillips, R.J.N.

1987-09-01

The problem with solar neutrinos is that there seem to be too few of them, at least near the top end of the spectrum, since the 37 Cl detector finds only about 35% of the standard predicted flux. Various kinds of explanation have been offered: (a) the standard solar model is wrong, (b) neutrinos decay, (c) neutrinos have magnetic moments, (d) neutrinos oscillate. The paper surveys developments in each of these areas, especially the possible enhancement of neutrino oscillations by matter effects and adiabatic level crossing. The prospects for further independent experiments are also discussed. (author)

Search for Muon neutrino → Tau neutrino oscillations motivation and feasibility

International Nuclear Information System (INIS)

Zacek, V.

1988-01-01

Theoretical prejudices derived from solar-neutrino matter oscillations and assumptions of neutrino mass hierarchies suggest, that neutrino-oscillations are observable in laboratory with mass parameters of Δm 2 = 10 -3 -10 4 eV 2 . In particular Muon neutrino → Tau neutrino appearance searches at accelerators seem strongly motivated

Sterile neutrinos with eV masses in cosmology — How disfavoured exactly?

DEFF Research Database (Denmark)

Hamann, Jan; Hannestad, Steen; Raffelt, G.G.

2011-01-01

We study cosmological models that contain sterile neutrinos with eV-range masses as suggested by reactor and short-baseline oscillation data. We confront these models with both precision cosmological data (probing the CMB decoupling epoch) and light-element abundances (probing the BBN epoch...... be circumvented by a small νe degeneracy. Any model containing eV-mass sterile neutrinos implies also strong modifications of other cosmological parameters. Notably, the inferred cold dark matter density can shift up by 20-75% relative to the standard ΛCDM value....

Non-unitarity, sterile neutrinos, and non-standard neutrino interactions

Energy Technology Data Exchange (ETDEWEB)

Blennow, Mattias [Department of Theoretical Physics, School of Engineering Sciences, KTH Royal Institute of Technology, Albanova University Center, 106 91 Stockholm (Sweden); Coloma, Pilar [Theoretical Physics Department, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Fernandez-Martinez, Enrique; Hernandez-Garcia, Josu [Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco E-28049 Madrid (Spain); Instituto de Física Teórica UAM/CSIC, Calle Nicolás Cabrera 13-15, Cantoblanco E-28049 Madrid (Spain); Lopez-Pavon, Jacobo [INFN, Sezione di Genova, via Dodecaneso 33, 16146 Genova (Italy); CERN, Theoretical Physics Department, Geneva (Switzerland)

2017-04-27

The simplest Standard Model extension to explain neutrino masses involves the addition of right-handed neutrinos. At some level, this extension will impact neutrino oscillation searches. In this work we explore the differences and similarities between the case in which these neutrinos are kinematically accessible (sterile neutrinos) or not (mixing matrix non-unitarity). We clarify apparent inconsistencies in the present literature when using different parametrizations to describe these effects and recast both limits in the popular neutrino non-standard interaction (NSI) formalism. We find that, in the limit in which sterile oscillations are averaged out at the near detector, their effects at the far detector coincide with non-unitarity at leading order, even in presence of a matter potential. We also summarize the present bounds existing in both limits and compare them with the expected sensitivities of near-future facilities taking the DUNE proposal as a benchmark. We conclude that non-unitarity effects are too constrained to impact present or near future neutrino oscillation facilities but that sterile neutrinos can play an important role at long baseline experiments. The role of the near detector is also discussed in detail.

New neutrino physics and the altered shapes of solar neutrino spectra

Science.gov (United States)

Lopes, Ilídio

2017-01-01

Neutrinos coming from the Sun's core have been measured with high precision, and fundamental neutrino oscillation parameters have been determined with good accuracy. In this work, we estimate the impact that a new neutrino physics model, the so-called generalized Mikheyev-Smirnov-Wolfenstein (MSW) oscillation mechanism, has on the shape of some of leading solar neutrino spectra, some of which will be partially tested by the next generation of solar neutrino experiments. In these calculations, we use a high-precision standard solar model in good agreement with helioseismology data. We found that the neutrino spectra of the different solar nuclear reactions of the pp chains and carbon-nitrogen-oxygen cycle have quite distinct sensitivities to the new neutrino physics. The He P and 8B neutrino spectra are the ones in which their shapes are more affected when neutrinos interact with quarks in addition to electrons. The shapes of the 15O and 17F neutrino spectra are also modified, although in these cases the impact is much smaller. Finally, the impact in the shapes of the P P and 13N neutrino spectra is practically negligible.

Addendum to 'Update on neutrino mixing in the early universe'

International Nuclear Information System (INIS)

Di Bari, P.

2003-01-01

In the light of the recent WMAP results we update the constraints on a class of nonstandard big bang nucleosynthesis (BBN) models with a simultaneous combination of nonstandard neutrino distributions and an extra effective number of neutrinos in the expansion rate. These models can be described in terms of the two parameters ΔN ν tot , constrained by the primordial helium abundance Y p measurement, and ΔN ν ρ , constrained by a combination of cosmic microwave background and primordial deuterium data. Small deviations from standard big bang nucleosynthesis are suggested. Different nonstandard scenarios can be distinguished by a measurement of the difference ΔN ν f ν =ΔN ν tot -ΔN ν ρ . From the current data we estimate ΔN ν f ν ≅-1.4 -1.4 +0.9 , mildly disfavoring solutions with a low expansion rate, characterized by ΔN ν f ν =0 and negative ΔN ν ρ . Active-sterile neutrino mixing could be a viable explanation only for high values of Y p > or approx. 0.24. The existence of large positive neutrino chemical potentials ξ i ∼0.05, implying ΔN ν ρ ≅0, would be a possible explanation of the data within the analyzed class of nonstandard BBN models. Interestingly, it would also provide a way to evade the cosmological bounds for ''class A 3+1'' four neutrino mixing models. A scenario with a decaying sterile neutrino is also considered

The first observations of wide-band interferometers and the spectra of relic gravitons

CERN Document Server

Giovannini, Massimo

2016-01-01

Stochastic backgrounds of relic gravitons of cosmological origin extend from frequencies of the order of the aHz up to the GHz range. Since the temperature and polarization anisotropies constrain the low frequency normalization of the spectra, in the concordance paradigm the strain amplitude corresponding to the frequency window of wide-band interferometers turns out to be, approximately, nine orders of magnitude smaller than the astounding signal recently reported and attributed to a binary black hole merger. The backgrounds of relic gravitons expected from the early Universe are compared with the stochastic foregrounds stemming from the estimated multiplicity of the astrophysical sources. It is suggested that while the astrophysical foregrounds are likely to dominate between few Hz and 10 kHz, relic gravitons with frequencies exceeding 100 kHz represent a potentially uncontaminated signal for the next generation of high-frequency detectors currently under scrutiny.

Solar neutrino observations and neutrino oscillations

International Nuclear Information System (INIS)

Kuo, T.K.; Pantaleone, J.

1990-01-01

The results of recent Kamiokande-II and 37 Cl solar-neutrino experiments are quantitatively analyzed assuming the Mikheyev-Smirnov-Wolfenstein solution to the solar-neutrino problem. It is found that the parameter region known as the ''large mass'' solution to the solar-neutrino problem is disfavored by a little more than 1 σ while the ''small mass'' and ''large angle'' solutions are in good agreement at this level. The implications on this analysis from time variations in the data are discussed

JUNO. Determination of the neutrino mass hierarchy using reactor neutrinos

Energy Technology Data Exchange (ETDEWEB)

Wonsak, Bjoern [Hamburg University, Inst. Exp. Phys., Hamburg (Germany)

2015-07-01

The Jiangmen Underground Neutrino Observatory (JUNO) is a medium-baseline reactor neutrino experiment located in China. Its aim is to determine the neutrino mass hierarchy at more than 3 sigma significance after six years of data taking by using a 20kt liquid scintillator detector. To achieve this goal, an energy resolution of less than 3%/√(E) is necessary, creating strict requirements on the detector design and the liquid scintillator. Moreover, JUNO will be the only experiment in the near future able to measure the solar mixing parameters with a precision of better than 1%. This is at the same level as our current knowledge on flavour mixing in the quark sector, marking an important milestone of neutrino physics. In addition, supernova neutrinos, geo-neutrinos, sterile neutrinos as well as solar and atmospheric neutrinos can be studied. JUNO was approved in 2013 and the construction of the underground facility started early this year. In this talk the status of the experiment and its prospects is discussed.

Neutrino GDR meeting

International Nuclear Information System (INIS)

Aguilar-Saavedra, J.A.; Camilleri, L.; Mention, G.; VanElewyck, V.; Verderi, M.; Blondel, A.; Augier, C.; Bellefon, A. de; Coc, A.; Duchesneau, D.; Favier, J.; Lesgourgues, J.; Payet, J.

2006-01-01

The purpose of the neutrino GDR (research program coordination) is to federate the activities of French research teams devoted to studying the neutrino. The presentations have been organized on 2 days. A review of the present status of the theoretical and experimental knowledge on neutrinos on a worldwide basis has been made on the first day while the second day has been dedicated to reporting the activities of the 5 following working groups: 1) determination of neutrino parameters, 2) physics beyond the standard model, 3) neutrinos in the universe, 4) neutrino detection, and 5) common tools. During the first day the American neutrino research program has been presented through the description of the 2 neutrino detection systems: Nova and Minor. The following neutrino experiments involving nuclear reactors: Chooz (France), Daya-bay (China), Reno (Korea) and Angra (Brazil) have also been reviewed. This document is made up of the slides of the presentations

Probing the nature of the neutrino: The boron solar-neutrino experiment

International Nuclear Information System (INIS)

Raghavan, R.S.; Pakvasa, S.

1988-01-01

With a welter of neutrino scenarios and uncertain solar models to be unraveled, can solar-neutrino experiments really break new ground in neutrino physics? A new solar-neutrino detector BOREX, based on the nuclide /sup 11/B, promises the tools for a definitive exploration of the nature of the neutrino and the structure of the Sun. Using double-mode detection by neutrino excitation of /sup 11/B via the neutral-weak-current- and the charged-current-mediated inverse β decay in the same target, independent measurements of the total neutrino flux regardless of flavor and the survival of electron neutrinos in solar matter and a vacuum can be made. Standard models of the Sun, and almost every proposed nonstandard model of the neutrino, can be subjected to sharp and direct tests. The development of BOREX, based on B-loaded liquid-scintillation techniques, is currently in progress

Neutrino Physics

CERN Document Server

Barenboim, G.

2014-12-10

The Standard Model has been incredibly successful in predicting the outcome of almost all the experiments done up so far. In it, neutrinos are mass-less. However, in recent years we have accumulated evidence pointing to tiny masses for the neutrinos (as compared to the charged leptons). These masses allow neutrinos to change their flavour and oscillate. In these lectures I review the properties of neutrinos in and beyond the Standard Model.

Higgs quartic coupling and neutrino sector evolution in 2UED models

KAUST Repository

Abdalgabar, A.

2014-05-20

Two compact universal extra-dimensional models are an interesting class of models for different theoretical and phenomenological issues, such as the justification of having three standard model fermion families, suppression of proton decay rate, dark matter parity from relics of the six-dimensional Lorentz symmetry, origin of masses and mixings in the standard model. However, these theories are merely effective ones, with typically a reduced range of validity in their energy scale. We explore two limiting cases of the three standard model generations all propagating in the bulk or all localised to a brane, from the point of view of renormalisation group equation evolutions for the Higgs sector and for the neutrino sector of these models. The recent experimental results of the Higgs boson from the LHC allow, in some scenarios, stronger constraints on the cutoff scale to be placed, from the requirement of the stability of the Higgs potential. 2014 The Author(s).

a Method of 3d Measurement and Reconstruction for Cultural Relics in Museums

Science.gov (United States)

Zheng, S.; Zhou, Y.; Huang, R.; Zhou, L.; Xu, X.; Wang, C.

2012-07-01

Three-dimensional measurement and reconstruction during conservation and restoration of cultural relics have become an essential part of a modem museum regular work. Although many kinds of methods including laser scanning, computer vision and close-range photogrammetry have been put forward, but problems still exist, such as contradiction between cost and good result, time and fine effect. Aimed at these problems, this paper proposed a structure-light based method for 3D measurement and reconstruction of cultural relics in museums. Firstly, based on structure-light principle, digitalization hardware has been built and with its help, dense point cloud of cultural relics' surface can be easily acquired. To produce accurate 3D geometry model from point cloud data, multi processing algorithms have been developed and corresponding software has been implemented whose functions include blunder detection and removal, point cloud alignment and merge, 3D mesh construction and simplification. Finally, high-resolution images are captured and the alignment of these images and 3D geometry model is conducted and realistic, accurate 3D model is constructed. Based on such method, a complete system including hardware and software are built. Multi-kinds of cultural relics have been used to test this method and results prove its own feature such as high efficiency, high accuracy, easy operation and so on.

Neutrino masses and oscillations

Energy Technology Data Exchange (ETDEWEB)

Smirnov, A Yu

1996-11-01

New effects related to refraction of neutrinos in different media are reviewed and implication of the effects to neutrino mass and mixing are discussed. Patterns of neutrino masses and mixing implied by existing hints/bounds are described. Recent results on neutrino mass generation are presented. They include neutrino masses in SO(10) GUT`s and models with anomalous U(1), generation of neutrino mass via neutrino-neutralino mixing, models of sterile neutrino. (author). 95 refs, 9 figs.

Phenomenology of neutrino oscillations at the neutrino factory

International Nuclear Information System (INIS)

Tang, Jian

2011-01-01

We consider the prospects for a neutrino factory measuring mixing angles, the CP violating phase and mass-squared differences by detecting wrong-charge muons arising from the chain μ + → ν e → ν μ → μ - and the right-charge muons coming from the chain μ + → anti ν μ → anti ν μ → μ - (similar to μ - chains), where ν e → ν μ and anti ν μ → anti ν μ are neutrino oscillation channels through a long baseline. First, we study physics with near detectors and consider the treatment of systematic errors including cross section errors, flux errors, and background uncertainties. We illustrate for which measurements near detectors are required, discuss how many are needed, and what the role of the flux monitoring is. We demonstrate that near detectors are mandatory for the leading atmospheric parameter measurements if the neutrino factory has only one baseline, whereas systematic errors partially cancel if the neutrino factory complex includes the magic baseline. Second, we perform the baseline and energy optimization of the neutrino factory including the latest simulation results from the magnetized iron neutrino detector (MIND). We also consider the impact of τ decays, generated by appearance channels ν μ → ν τ and ν e → ν τ , on the discovery reaches of the mass orderings, the leptonic CP violation, and the non-zero θ 13 , which we find to be negligible for the considered detector. Third, we make a comparison of a high energy neutrino factory to a low energy neutrino factory and find that they are just two versions of the same experiment optimized for different regions of the parameter space. In addition, we briefly comment on whether it is useful to build the bi-magic baseline at the low energy neutrino factory. Finally, the effects of one additional massive sterile neutrino are discussed in the context of a combined short and long baseline setup. It is found that near detectors can provide the required sensitivity at the

Detecting relic gravitational waves in the CMB: Optimal parameters and their constraints

International Nuclear Information System (INIS)

Zhao, W.; Baskaran, D.

2009-01-01

The prospect of detecting relic gravitational waves, through their imprint in the cosmic microwave background radiation, provides an excellent opportunity to study the very early Universe. In the simplest viable theoretical models the relic gravitational wave background is characterized by two parameters, the tensor-to-scalar ratio r and the tensor spectral index n t . In this paper, we analyze the potential joint constraints on these two parameters, r and n t , using the data from the upcoming cosmic microwave background radiation experiments. Introducing the notion of the best-pivot multipole l t *, we find that at this pivot multipole the parameters r and n t are uncorrelated, and have the smallest variances. We derive the analytical formulas for the best-pivot multipole number l t *, and the variances of the parameters r and n t . We verify these analytical calculations using numerical simulation methods, and find agreement to within 20%. The analytical results provide a simple way to estimate the detection ability for the relic gravitational waves by the future observations of the cosmic microwave background radiation.

Three neutrino flavors: Oscillations, mixing, and the solar-neutrino problem

International Nuclear Information System (INIS)

Pantaleone, J.

1991-01-01

An analytical, quantitative description of solar-neutrino propagation is presented which includes three flavors, matter dependence, and long-wavelength effects. Using the derived expression for the electron-neutrino survival probability, it is demonstrated that mixing is possible between the two-flavor Mikheyev-Smirnov-Wolfenstein and two-flavor long-wavelength solutions to the solar-neutrino problem. However, adiabatic conversion of a neutrino mass eigenstate tends to suppress all subsequent long-wavelength effects such as ''seasonal'' variations in the solar-neutrino flux

Sudbury Neutrino Observatory

International Nuclear Information System (INIS)

Beier, E.W.

1992-03-01

This document is a technical progress report on work performed at the University of Pennsylvania during the current year on the Sudbury Neutrino Observatory project. The motivation for the experiment is the measurement of neutrinos emitted by the sun. The Sudbury Neutrino Observatory (SNO) is a second generation dedicated solar neutrino experiment which will extend the results of our work with the Kamiokande II detector by measuring three reactions of neutrinos rather than the single reaction measured by the Kamiokande experiment. The collaborative project includes physicists from Canada, the United Kingdom, and the United States. Full funding for the construction of this facility was obtained in January 1990, and its construction is estimated to take five years. The motivation for the SNO experiment is to study the fundamental properties of neutrinos, in particular the mass and mixing parameters, which remain undetermined after decades of experiments in neutrino physics utilizing accelerators and reactors as sources of neutrinos. To continue the study of neutrino properties it is necessary to use the sun as a neutrino source. The long distance to the sun makes the search for neutrino mass sensitive to much smaller mass than can be studied with terrestrial sources. Furthermore, the matter density in the sun is sufficiently large to enhance the effects of small mixing between electron neutrinos and mu or tau neutrinos. This experiment, when combined with the results of the radiochemical 37 Cl and 71 Ga experiments and the Kamiokande II experiment, should extend our knowledge of these fundamental particles, and as a byproduct, improve our understanding of energy generation in the sun

Resonant spin-flavor precession of neutrino and the solar neutrino problem

International Nuclear Information System (INIS)

Akhmedov, E.Kh.; Bychuk, O.V.; AN SSSR, Moscow

1989-01-01

Resonant amplification of spin-flavor precession of neutrinos in solar matter is considered. Some possible consequences of the process are discussed. It is shown that resonant spin-flavor neutrino precession may account for the deficit of solar neutrinos in Davis' experiment and the anticorrelation between the rate of neutrino counting and solar activity. Experiments are considered which should make it possible to distinguish between spin-flavor neutrino precession and the Mikheyev-Smirnov-Wolfenstein effect. A new restriction on the usual spin precession of solar neutrinos is derived

Neutrino Physics at Drexel

Energy Technology Data Exchange (ETDEWEB)

Lane, Charles [Drexel Univ., Philadelphia, PA (United States); Dolinski, Michelle [Drexel Univ., Philadelphia, PA (United States); Neilson, Russell [Drexel Univ., Philadelphia, PA (United States)

2017-07-11

Our primary goal is to improve the understanding of the properties and interactions of neutrinos. We are pursuing this by means of the DUNE long-baseline and PROSPECT short-baseline neutrino experiments. For DUNE, a neutrino beam from Fermilab will be detected at the SURF facility in South Dakota, with the aim of determining the neutrino mass hierarchy (the mass ordering of neutrino flavors), and a measurement or limit on CP-violation via neutrinos. Our near-term experimental goal is to improve the characterization of the neutrino beam by measurements of muons produced as a byproduct of neutrino beam generation, to quantify the beam composition and flux. The short-range neutrino program has the aim of using the HFIR reactor at Oak Ridge as a neutrino source, with a detector placed nearby to find if there are short-distance oscillations to sterile neutrino flavors, and to resolve the 'reactor neutrino spectral anomaly' which has shown up as an unexplained 'bump' in the neutrino energy spectrum in recent experiments.

Massive neutrinos flavor mixing of leptons and neutrino oscillations

CERN Document Server

2015-01-01

Since the discovery of neutrino oscillations neutrino physics has become an interesting field of research in physics. They imply that neutrino must have a small mass and that the neutrinos, coupled to the charged leptons, are mixtures of the mass eigenstates, analogous to the flavor mixing of the quarks. The mixing angles for the quarks are small, but for the leptons two of the mixing angles are large. The masses of the three neutrinos must be very small, less than 1 eV, but from the oscillation experiments we only know the mass differences — the absolute masses are still unknown. Also we do not know, if the masses of the neutrinos are Dirac masses, as the masses of the charged leptons and of the quarks, or whether they are Majorana masses. In this volume, an overview of the present state of research in neutrino physics is given by well-known experimentalists and theorists. The contents — originated from talks and discussions at a recent conference addressing some of the most pressing open questions in n...

Los Neutrinos Los Neutrinos

Directory of Open Access Journals (Sweden)

Julián Félix

2012-02-01

Full Text Available From all the proposals to understand the structure of matter, and the way the natural world is conformed, the one about neutrinos is the most enigmatic, abstract, and foreign to immediate experience; however, this is the one that has delved more deeply over the nearly eighty years since it was formulated by Wolfgang Pauli –in 1930- as a radical proposition to understand nucleon decay, and the decay of other particles, without the violation of the principle of conservation of energy and momentum at subatomic level. This proposition has evolved through the years, and from Pauli’s original idea only the basic elements remain.This article contains the tale of the hypothesis of neutrinos, its early history, its evolution up to present day, and the efforts done nowadays to study them. In summary, this is the physics of neutrinos. De todas las propuestas para entender la estructura de la materia, y la conformación del mundo natural, los neutrinos es la más enigmática, abstracta, y ajena a la experiencia inmediata; sin embargo, es la que más hondo ha ido calando a lo largo de los ya casi ochenta años de haber sido formulada por Wolfgang Pauli –en el año 1930- como una medida radical para entender el decaimiento de los nucleones, y otras partículas, sin que se violara el principio de la conservación de la energía y del momento a nivel subatómico. La propuesta ha evolucionado a lo largo de los años, y de la idea original de Pauli ya sólo lo básico permanece. En este artículo está el relato de la hipótesis de los neutrinos, su historia primera, su evolución hasta el presente, los esfuerzos que en la actualidad se realizan para estudiarlos. En breve, ésta es la física de los neutrinos.

The Intermediate Neutrino Program

CERN Document Server

Adams, C.; Ankowski, A.M.; Asaadi, J.A.; Ashenfelter, J.; Axani, S.N.; Babu, K.; Backhouse, C.; Band, H.R.; Barbeau, P.S.; Barros, N.; Bernstein, A.; Betancourt, M.; Bishai, M.; Blucher, E.; Bouffard, J.; Bowden, N.; Brice, S.; Bryan, C.; Camilleri, L.; Cao, J.; Carlson, J.; Carr, R.E.; Chatterjee, A.; Chen, M.; Chen, S.; Chiu, M.; Church, E.D.; Collar, J.I.; Collin, G.; Conrad, J.M.; Convery, M.R.; Cooper, R.L.; Cowen, D.; Davoudiasl, H.; de Gouvea, A.; Dean, D.J.; Deichert, G.; Descamps, F.; DeYoung, T.; Diwan, M.V.; Djurcic, Z.; Dolinski, M.J.; Dolph, J.; Donnelly, B.; Dwyer, D.A.; Dytman, S.; Efremenko, Y.; Everett, L.L.; Fava, A.; Figueroa-Feliciano, E.; Fleming, B.; Friedland, A.; Fujikawa, B.K.; Gaisser, T.K.; Galeazzi, M.; Galehouse, D.C.; Galindo-Uribarri, A.; Garvey, G.T.; Gautam, S.; Gilje, K.E.; Gonzalez-Garcia, M.; Goodman, M.C.; Gordon, H.; Gramellini, E.; Green, M.P.; Guglielmi, A.; Hackenburg, R.W.; Hackenburg, A.; Halzen, F.; Han, K.; Hans, S.; Harris, D.; Heeger, K.M.; Herman, M.; Hill, R.; Holin, A.; Huber, P.; Jaffe, D.E.; Johnson, R.A.; Joshi, J.; Karagiorgi, G.; Kaufman, L.J.; Kayser, B.; Kettell, S.H.; Kirby, B.J.; Klein, J.R.; Kolomensky, Yu. G.; Kriske, R.M.; Lane, C.E.; Langford, T.J.; Lankford, A.; Lau, K.; Learned, J.G.; Ling, J.; Link, J.M.; Lissauer, D.; Littenberg, L.; Littlejohn, B.R.; Lockwitz, S.; Lokajicek, M.; Louis, W.C.; Luk, K.; Lykken, J.; Marciano, W.J.; Maricic, J.; Markoff, D.M.; Martinez Caicedo, D.A.; Mauger, C.; Mavrokoridis, K.; McCluskey, E.; McKeen, D.; McKeown, R.; Mills, G.; Mocioiu, I.; Monreal, B.; Mooney, M.R.; Morfin, J.G.; Mumm, P.; Napolitano, J.; Neilson, R.; Nelson, J.K.; Nessi, M.; Norcini, D.; Nova, F.; Nygren, D.R.; Orebi Gann, G.D.; Palamara, O.; Parsa, Z.; Patterson, R.; Paul, P.; Pocar, A.; Qian, X.; Raaf, J.L.; Rameika, R.; Ranucci, G.; Ray, H.; Reyna, D.; Rich, G.C.; Rodrigues, P.; Romero, E.Romero; Rosero, R.; Rountree, S.D.; Rybolt, B.; Sanchez, M.C.; Santucci, G.; Schmitz, D.; Scholberg, K.; Seckel, D.; Shaevitz, M.; Shrock, R.; Smy, M.B.; Soderberg, M.; Sonzogni, A.; Sousa, A.B.; Spitz, J.; St. John, J.M.; Stewart, J.; Strait, J.B.; Sullivan, G.; Svoboda, R.; Szelc, A.M.; Tayloe, R.; Thomson, M.A.; Toups, M.; Vacheret, A.; Vagins, M.; Van de Water, R.G.; Vogelaar, R.B.; Weber, M.; Weng, W.; Wetstein, M.; White, C.; White, B.R.; Whitehead, L.; Whittington, D.W.; Wilking, M.J.; Wilson, R.J.; Wilson, P.; Winklehner, D.; Winn, D.R.; Worcester, E.; Yang, L.; Yeh, M.; Yokley, Z.W.; Yoo, J.; Yu, B.; Yu, J.; Zhang, C.

2015-01-01

The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summ...

Underground neutrino astronomy

International Nuclear Information System (INIS)

Schramm, D.N.

1983-02-01

A review is made of possible astronomical neutrino sources detectable with underground facilities. Comments are made about solar neutrinos and gravitational-collapse neutrinos, and particular emphasis is placed on ultra-high-energy astronomical neutrino sources. An appendix mentions the exotic possibility of monopolonium

Neutrino-Induced Nucleosynthesis in Helium Shells of Early Core-Collapse Supernovae

Directory of Open Access Journals (Sweden)

Banerjee Projjwal

2016-01-01

Full Text Available We summarize our studies on neutrino-driven nucleosynthesis in He shells of early core-collapse supernovae with metallicities of Z ≲ 10−3 Z⊙. We find that for progenitors of ∼ 11–15 M⊙, the neutrons released by 4He(ν¯ee, e+n3H in He shells can be captured to produce nuclei with mass numbers up to A ∼ 200. This mechanism is sensitive to neutrino emission spectra and flavor oscillations. In addition, we find two new primary mechanisms for neutrino-induced production of 9Be in He shells. The first mechanism produces 9Be via 7Li(n,γ8Li(n,γ9Li(e− ν¯ee9Be and relies on a low explosion energy for its survival. The second mechanism operates in progenitors of ∼ 8 M⊙, where 9Be can be produced directly via 7Li(3H, n09Be during the rapid expansion of the shocked Heshell material. The light nuclei 7Li and 3H involved in these mechanisms are produced by neutrino interactions with 4He. We discuss the implications of neutrino-induced nucleosynthesis in He shells for interpreting the elemental abundances in metal-poor stars.

Neutrinos: Theory and Phenomenology

Energy Technology Data Exchange (ETDEWEB)

Parke, Stephen

2013-10-22

The theory and phenomenology of neutrinos will be addressed, especially that relating to the observation of neutrino flavor transformations. The current status and implications for future experiments will be discussed with special emphasis on the experiments that will determine the neutrino mass ordering, the dominant flavor content of the neutrino mass eigenstate with the smallest electron neutrino content and the size of CP violation in the neutrino sector. Beyond the neutrino Standard Model, the evidence for and a possible definitive experiment to confirm or refute the existence of light sterile neutrinos will be briefly discussed.

Search for sterile neutrinos at a new short-baseline CERN neutrino beam

International Nuclear Information System (INIS)

Mauri, N.

2014-01-01

In the last few years the experimental results on neutrino/anti-neutrino oscillations at Short-Baseline (SBL) showed a tension with several phenomenological models. The recent and carefully recomputed anti-neutrino fluxes from nuclear reactors have further increased this tension drawing a picture not fully compatible with the 3 neutrino oscillation scenario. A sterile neutrino is a neutral lepton which does not couple with W/Z bosons. it is not an exotic particle, its existence being a natural consequence of neutrinos having a non-zero mass. Sterile neutrinos can mix with the active ones through additional mass eigenstates, with no necessary mass scale. We will present an experimental search for sterile neutrinos with a new CERN-SPS neutrino beam using muon spectrometers and large LAr detectors. To definitely clarify the physics issue, the proposed experiment will study oscillations in a muon neutrino / antineutrino beam both in appearance and disappearance modes, exploring the Δm 2 ∼ 1 eV 2 range

The Intermediate Neutrino Program

Energy Technology Data Exchange (ETDEWEB)

Adams, C.; et al.

2015-03-23

The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.

The Intermediate Neutrino Program

Energy Technology Data Exchange (ETDEWEB)

Adams, C. [Yale Univ., New Haven, CT (United States); Alonso, J. R. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Ankowski, A. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Asaadi, J. A. [Syracuse Univ., NY (United States); Ashenfelter, J. [Yale Univ., New Haven, CT (United States); Axani, S. N. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Babu, K [Oklahoma State Univ., Stillwater, OK (United States); Backhouse, C. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Band, H. R. [Yale Univ., New Haven, CT (United States); Barbeau, P. S. [Duke Univ., Durham, NC (United States); Barros, N. [Univ. of Pennsylvania, Philadelphia, PA (United States); Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Betancourt, M. [Illinois Inst. of Technology, Chicago, IL (United States); Bishai, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blucher, E. [Univ. of Chicago, IL (United States); Bouffard, J. [State Univ. of New York (SUNY), Albany, NY (United States); Bowden, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brice, S. [Illinois Inst. of Technology, Chicago, IL (United States); Bryan, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Camilleri, L. [Columbia Univ., New York, NY (United States); Cao, J. [Inst. of High Energy Physics, Beijing (China); Carlson, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carr, R. E. [Columbia Univ., New York, NY (United States); Chatterjee, A. [Univ. of Texas, Arlington, TX (United States); Chen, M. [Univ. of California, Irvine, CA (United States); Chen, S. [Tsinghua Univ., Beijing (China); Chiu, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Church, E. D. [Illinois Inst. of Technology, Chicago, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Collar, J. I. [Univ. of Chicago, IL (United States); Collin, G. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Conrad, J. M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Convery, M. R. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Cooper, R. L. [Indiana Univ., Bloomington, IN (United States); Cowen, D. [Pennsylvania State Univ., University Park, PA (United States); Davoudiasl, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gouvea, A. D. [Northwestern Univ., Evanston, IL (United States); Dean, D. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deichert, G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Descamps, F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); DeYoung, T. [Michigan State Univ., East Lansing, MI (United States); Diwan, M. V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Djurcic, Z. [Argonne National Lab. (ANL), Argonne, IL (United States); Dolinski, M. J. [Drexel Univ., Philadelphia, PA (United States); Dolph, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Donnelly, B. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Dwyer, D. A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dytman, S. [Univ. of Pittsburgh, PA (United States); Efremenko, Y. [Univ. of Tennessee, Knoxville, TN (United States); Everett, L. L. [Univ. of Wisconsin, Madison, WI (United States); Fava, A. [University of Padua, Padova (Italy); Figueroa-Feliciano, E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Fleming, B. [Yale Univ., New Haven, CT (United States); Friedland, A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fujikawa, B. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gaisser, T. K. [Univ. of Delaware, Newark, DE (United States); Galeazzi, M. [Univ. of Miami, FL (United States); Galehouse, DC [Univ. of Akron, OH (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Garvey, G. T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gautam, S. [Tribhuvan Univ., Kirtipur (Nepal); Gilje, K. E. [Illinois Inst. of Technology, Chicago, IL (United States); Gonzalez-Garcia, M. [Stony Brook Univ., NY (United States); Goodman, M. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Gordon, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gramellini, E. [Yale Univ., New Haven, CT (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Guglielmi, A. [University of Padua, Padova (Italy); Hackenburg, R. W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hackenburg, A. [Yale Univ., New Haven, CT (United States); Halzen, F. [Univ. of Wisconsin, Madison, WI (United States); Han, K. [Yale Univ., New Haven, CT (United States); Hans, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Harris, D. [Illinois Inst. of Technology, Chicago, IL (United States); Heeger, K. M. [Yale Univ., New Haven, CT (United States); Herman, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hill, R. [Univ. of Chicago, IL (United States); Holin, A. [Univ. College London, Bloomsbury (United Kingdom); Huber, P. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Jaffe, D. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Johnson, R. A. [Univ. of Cincinnati, OH (United States); Joshi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Karagiorgi, G. [Univ. of Manchester (United Kingdom); Kaufman, L. J. [Indiana Univ., Bloomington, IN (United States); Kayser, B. [Illinois Inst. of Technology, Chicago, IL (United States); Kettell, S. H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kirby, B. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Klein, J. R. [Univ. of Texas, Arlington, TX (United States); Kolomensky, Y. G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Kriske, R. M. [Univ. of Minnesota, Minneapolis, MN (United States); Lane, C. E. [Drexel Univ., Philadelphia, PA (United States); Langford, T. J. [Yale Univ., New Haven, CT (United States); Lankford, A. [Univ. of California, Irvine, CA (United States); Lau, K. [Univ. of Houston, TX (United States); Learned, J. G. [Univ. of Hawaii, Honolulu, HI (United States); Ling, J. [Univ. of Illinois, Urbana-Champaign, IL (United States); Link, J. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Lissauer, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littenberg, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littlejohn, B. R. [Illinois Inst. of Technology, Chicago, IL (United States); Lockwitz, S. [Illinois Inst. of Technology, Chicago, IL (United States); Lokajicek, M. [Inst. of Physics of the Academy of Sciences of Czech Republic, Prague (Czech Republic); Louis, W. C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Luk, K. [Univ. of California, Berkeley, CA (United States); Lykken, J. [Illinois Inst. of Technology, Chicago, IL (United States); Marciano, W. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Maricic, J. [Univ. of Hawaii, Honolulu, HI (United States); Markoff, D. M. [North Carolina Central Univ., Durham, NC (United States); Caicedo, D. A. M. [Illinois Inst. of Technology, Chicago, IL (United States); Mauger, C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mavrokoridis, K. [Univ. of Liverpool (United Kingdom); McCluskey, E. [Illinois Inst. of Technology, Chicago, IL (United States); McKeen, D. [Univ. of Washington, Seattle, WA (United States); McKeown, R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mills, G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mocioiu, I. [Pennsylvania State Univ., University Park, PA (United States); Monreal, B. [Univ. of California, Santa Barbara, CA (United States); Mooney, M. R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Morfin, J. G. [Illinois Inst. of Technology, Chicago, IL (United States); Mumm, P. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Napolitano, J. [Temple Univ., Philadelphia, PA (United States); Neilson, R. [Drexel Univ., Philadelphia, PA (United States); Nelson, J. K. [College of William and Mary, Williamsburg, VA (United States); Nessi, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Norcini, D. [Yale Univ., New Haven, CT (United States); Nova, F. [Univ. of Texas, Austin, TX (United States); Nygren, D. R. [Univ. of Texas, Arlington, TX (United States); Gann, GDO [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Palamara, O. [Illinois Inst. of Technology, Chicago, IL (United States); Parsa, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States); Patterson, R. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Paul, P. [Stony Brook Univ., NY (United States); Pocar, A. [Univ. of Massachusetts, Amherst, MA (United States); Qian, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Raaf, J. L. [Illinois Inst. of Technology, Chicago, IL (United States); Rameika, R. [Illinois Inst. of Technology, Chicago, IL (United States); Ranucci, G. [National Inst. of Nuclear Physics, Milano (Italy); Ray, H. [Univ. of Florida, Gainesville, FL (United States); Reyna, D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rich, G. C. [Triangle Universities Nuclear Lab., Durham, NC (United States); Rodrigues, P. [Univ. of Rochester, NY (United States); Romero, E. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Rosero, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rountree, S. D. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Rybolt, B. [Univ. of Tennessee, Knoxville, TN (United States); Sanchez, M. C. [Iowa State Univ., Ames, IA (United States); Santucci, G. [Stony Brook Univ., NY (United States); Schmitz, D. [Univ. of Chicago, IL (United States); Scholberg, K. [Duke Univ., Durham, NC (United States); Seckel, D. [Univ. of Delaware, Newark, DE (United States); Shaevitz, M. [Columbia Univ., New York, NY (United States); Shrock, R. [Stony Brook Univ., NY (United States); Smy, M. B. [Univ. of California, Irvine, CA (United States); Soderberg, M. [Syracuse Univ., NY (United States); Sonzogni, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sousa, A. B. [Univ. of Cincinnati, OH (United States); Spitz, J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); John, J. M. S. [Univ. of Cincinnati, OH (United States); Stewart, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Strait, J. B. [Illinois Inst. of Technology, Chicago, IL (United States); Sullivan, G. [Univ. of Maryland, College Park, MD (United States); Svoboda, R. [Univ. of California, Davis, CA (United States); Szelc, A. M. [Yale Univ., New Haven, CT (United States); Tayloe, R. [Indiana Univ., Bloomington, IN (United States); Thomson, M. A. [Univ. of Cambridge (United Kingdom); Toups, M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Vacheret, A. [Univ. of Oxford (United Kingdom); Vagins, M. [Univ. of California, Irvine, CA (United States); Water, R. G. V. D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vogelaar, R. B. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Weber, M. [Bern (Switzerland); Weng, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wetstein, M. [Univ. of Chicago, IL (United States); White, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); White, B. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Whitehead, L. [Univ. of Houston, TX (United States); Whittington, D. W. [Indiana Univ., Bloomington, IN (United States); Wilking, M. J. [Stony Brook Univ., NY (United States); Wilson, R. J. [Colorado State Univ., Fort Collins, CO (United States); Wilson, P. [Illinois Inst. of Technology, Chicago, IL (United States); Winklehner, D. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Winn, D. R. [Fairfield Univ., CT (United States); Worcester, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, L. [Univ. of Illinois, Urbana-Champaign, IL (United States); Yeh, M [Brookhaven National Lab. (BNL), Upton, NY (United States); Yokley, Z. W. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Yoo, J. [Illinois Inst. of Technology, Chicago, IL (United States); Yu, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yu, J. [Univ. of Texas, Arlington, TX (United States); Zhang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2017-04-03

The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.

Late Quaternary sea level and environmental changes from relic ...

Indian Academy of Sciences (India)

Relic carbonate deposits along the western margin of India occur as dolomite crusts, aragonite sands (pelletal / oolitic) and aragonite-cemented limestones, oyster shells, corals, encrusted coralline algal and foraminiferal-dominated nodules. The petrology and mineralogy of the deposits indicate that except for aragonite ...

Geometric phase of neutrinos: Differences between Dirac and Majorana neutrinos

Science.gov (United States)

Capolupo, A.; Giampaolo, S. M.; Hiesmayr, B. C.; Vitiello, G.

2018-05-01

We analyze the non-cyclic geometric phase for neutrinos. We find that the geometric phase and the total phase associated to the mixing phenomenon provide a theoretical tool to distinguish between Dirac and Majorana neutrinos. Our results hold for neutrinos propagating in vacuum and through the matter. We feed the values of the experimental parameters in our formulas in order to make contact with experiments. Although it remains an open question how the geometric phase of neutrinos could be detected, our theoretical results may open new scenarios in the investigation of the neutrino nature.

The Neutrinos Saga

International Nuclear Information System (INIS)

La Souchere, Marie-Christine de; Moran, John

2009-04-01

The author proposes a history of the discovery and study of neutrinos. This history starts shortly after the discovery of radioactivity in 1896 with the observation of an inhomogeneous deceleration of electrons in the radioactive source which raised an issue of shortage of energy. Pauli then introduced the idea of a ghost particle which could preserve the principle of energy conservation and also the issue of statistics related to the laws of quantum mechanics. Works by the Joliot-Curies and Chadwick resulted in the identification of a neutral particle, first called a neutron, and then neutrino. The author then reports experiments performed to highlight neutrinos, and to identify different forms of neutrinos: muon, tau, lepton. She also addresses questions raised by solar neutrinos, experiments proving the metamorphosis of electron neutrinos into muon neutrinos. She discusses the interest of neutrino as cosmic messengers as they are emitted by various cosmic events, and also as a way to study dark matter

Stochastic Background of Relic Scalar Gravitational Waves tuned by Extended Gravity

International Nuclear Information System (INIS)

De Laurentis, Mariafelicia; Capozziello, Salvatore

2009-01-01

A stochastic background of relic gravitational waves is achieved by the so called adiabatically-amplified zero-point fluctuations process derived from early inflation. It provides a distinctive spectrum of relic gravitational waves. In the framework of scalar-tensor gravity, we discuss the scalar modes of gravitational waves and the primordial production of this scalar component which is generated beside tensorial one. Then analyze seven different viable f(R)-gravities towards the Solar System tests and stochastic gravitational waves background. It is demonstrated that seven viable f(R)-gravities under consideration not only satisfy the local tests, but additionally, pass the above PPN-and stochastic gravitational waves bounds for large classes of parameters.

Identifying the neutrino mass hierarchy with supernova neutrinos

International Nuclear Information System (INIS)

Tomas, Ricard

2006-01-01

We review how a high-statistics observation of the neutrino signal from a future galactic core-collapse supernova (SN) may be used to discriminate between different neutrino mixing scenarios. We discuss two complementary methods that allow for the positive identification of the mass hierarchy without knowledge of the emitted neutrino fluxes, provided that the 13-mixing angle is large, sin 2 θ 13 -5 . These two approaches are the observation of modulations in the neutrino spectra by Earth matter effects or by the passage of shock waves through the SN envelope. If the value of the 13-mixing angle is unknown, using additionally the information encoded in the prompt neutronization ν e burst-a robust feature found in all modern SN simulations-can be sufficient to fix both the neutrino hierarchy and to decide whether θ 13 is 'small' or 'large'

Relic gravitational waves and the generalized second law

International Nuclear Information System (INIS)

Izquierdo, German; Pavon, Diego

2004-01-01

The generalized second law of gravitational thermodynamics is applied to the present era of accelerated expansion of the Universe. In spite of the fact that the entropy of matter and relic gravitational waves inside the event horizon diminish, the mentioned law is fulfilled provided that the expression for the entropy density of the gravitational waves satisfies a certain condition

Unblinding the dark matter blind spots

International Nuclear Information System (INIS)

Han, Tao; Kling, Felix

2017-01-01

The dark matter (DM) blind spots in the Minimal Supersymmetric Standard Model (MSSM) refer to the parameter regions where the couplings of the DM particles to the Z-boson or the Higgs boson are almost zero, leading to vanishingly small signals for the DM direct detections. In this paper, we carry out comprehensive analyses for the DM searches under the blind-spot scenarios in MSSM. Guided by the requirement of acceptable DM relic abundance, we explore the complementary coverage for the theory parameters at the LHC, the projection for the future underground DM direct searches, and the indirect searches from the relic DM annihilation into photons and neutrinos. We find that (i) the spin-independent (SI) blind spots may be rescued by the spin-dependent (SD) direct detection in the future underground experiments, and possibly by the indirect DM detections from IceCube and SuperK neutrino experiments; (ii) the detection of gamma rays from Fermi-LAT may not reach the desirable sensitivity for searching for the DM blind-spot regions; (iii) the SUSY searches at the LHC will substantially extend the discovery region for the blind-spot parameters. As a result, the dark matter blind spots thus may be unblinded with the collective efforts in future DM searches.

Neutrinos (1/3)

CERN Multimedia

CERN. Geneva

2013-01-01

The neutrino, the lightest and most weakly interacting particle of the Standard Model has revealed itself as the messenger of very exciting news in particle physics: there is Physics Beyond the Standard Model. All this thanks to the quantum-mechanical phenomenon of flavour oscillations which is intrinsically connected to the question of neutrino mass and which has been observed in neutrinos produced in natural sources, like the Sun and the Earth's atmosphere, as well as with human made neutrino beams at accelerator and reactors. The purpose of these lectures is to overview some aspects of the phenomenology of massive neutrinos. I will present the simplest extensions for adding neutrino masses to the SM, and then I will describe the phenomenology associated with neutrino oscillations in vacuum and in matter and its present signatures.

Phenomenology of neutrino oscillations at the neutrino factory

Energy Technology Data Exchange (ETDEWEB)

Tang, Jian

2011-12-19

We consider the prospects for a neutrino factory measuring mixing angles, the CP violating phase and mass-squared differences by detecting wrong-charge muons arising from the chain {mu}{sup +} {yields} {nu}{sub e} {yields} {nu}{sub {mu}} {yields} {mu}{sup -} and the right-charge muons coming from the chain {mu}{sup +} {yields} anti {nu}{sub {mu}} {yields} anti {nu}{sub {mu}} {yields} {mu}{sup -} (similar to {mu}{sup -} chains), where {nu}{sub e} {yields} {nu}{sub {mu}} and anti {nu}{sub {mu}} {yields} anti {nu}{sub {mu}} are neutrino oscillation channels through a long baseline. First, we study physics with near detectors and consider the treatment of systematic errors including cross section errors, flux errors, and background uncertainties. We illustrate for which measurements near detectors are required, discuss how many are needed, and what the role of the flux monitoring is. We demonstrate that near detectors are mandatory for the leading atmospheric parameter measurements if the neutrino factory has only one baseline, whereas systematic errors partially cancel if the neutrino factory complex includes the magic baseline. Second, we perform the baseline and energy optimization of the neutrino factory including the latest simulation results from the magnetized iron neutrino detector (MIND). We also consider the impact of {tau} decays, generated by appearance channels {nu}{sub {mu}} {yields} {nu}{sub {tau}} and {nu}{sub e} {yields} {nu}{sub {tau}}, on the discovery reaches of the mass orderings, the leptonic CP violation, and the non-zero {theta}{sub 13}, which we find to be negligible for the considered detector. Third, we make a comparison of a high energy neutrino factory to a low energy neutrino factory and find that they are just two versions of the same experiment optimized for different regions of the parameter space. In addition, we briefly comment on whether it is useful to build the bi-magic baseline at the low energy neutrino factory. Finally, the

Testing the big bang: Light elements, neutrinos, dark matter and large-scale structure

Energy Technology Data Exchange (ETDEWEB)

Schramm, D.N. (Chicago Univ., IL (United States) Fermi National Accelerator Lab., Batavia, IL (United States))

1991-06-01

In this series of lectures, several experimental and observational tests of the standard cosmological model are examined. In particular, detailed discussion is presented regarding nucleosynthesis, the light element abundances and neutrino counting; the dark matter problems; and the formation of galaxies and large-scale structure. Comments will also be made on the possible implications of the recent solar neutrino experimental results for cosmology. An appendix briefly discusses the 17 keV thing'' and the cosmological and astrophysical constraints on it. 126 refs., 8 figs., 2 tabs.

The neutrino mirror

International Nuclear Information System (INIS)

Vannucci, F.

2003-09-01

The neutrino is not an elementary particle like others, it is the most stunning of all: the neutrino is undetectable by itself, we have only indirect evidences of its existence, but the neutrino is essential to explain the weak interaction, to understand why matter triumphed over anti-matter just after the Big-bang, or to solve the riddle of the hidden mass of the universe. This book is a popular work dedicated to the neutrino from its discovery in beta decays to the most recent theories such as neutrino oscillations, and via the worldwide experiments dedicated to the study of the neutrinos. (A.C.)

The solar neutrino problem after the GALLEX artificial neutrino source experiment

International Nuclear Information System (INIS)

Vignaud, D.

1995-01-01

Using an intense 51 Cr artificial neutrino source (more than 60 PBq), the GALLEX solar neutrino collaboration has recently checked that its radiochemical detector was fully efficient for the detection of solar neutrinos. After this crucial result, the status of the solar neutrino problem is reviewed, with emphasis on how neutrino oscillations may explain (through the MSW effect) the different deficits observed in the four existing experiments. (author). 25 refs., 5 figs., 1 tab

Cold dark matter plus not-so-clumpy dark relics

NARCIS (Netherlands)

Diamanti, R.; Ando, S.; Gariazzo, S.; Mena, O.; Weniger, C.

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark

Non-Unitarity, sterile neutrinos, and Non-Standard neutrino Interactions

CERN Document Server

Blennow, Mattias; Fernandez-Martinez, Enrique; Hernandez-Garcia, Josu; Lopez-Pavon, Jacobo

2017-04-27

The simplest Standard Model extension to explain neutrino masses involves the addition of right-handed neutrinos. At some level, this extension will impact neutrino oscillation searches. In this work we explore the differences and similarities between the case in which these neutrinos are kinematically accessible (sterile neutrinos) or not (mixing matrix non-unitarity). We clarify apparent inconsistencies in the present literature when using different parametrizations to describe these effects and recast both limits in the popular neutrino non-standard interaction (NSI) formal- ism. We find that, in the limit in which sterile oscillations are averaged out at the near detector, their effects at the far detector coincide with non-unitarity at leading order, even in presence of a matter potential. We also summarize the present bounds existing in both limits and compare them with the expected sensitivities of near-future facilities taking the DUNE proposal as a bench- mark. We conclude that non-unitarity effects ...

Neutrino oscillations and neutrino-electron scattering

International Nuclear Information System (INIS)

Kayser, B.; Rosen, S.P.

1980-10-01

Neutrino flavor oscillations can significantly alter the cross section for neutrino-electron scattering. As a result, such oscillations can affect the comparison between existing reactor data and theories of neutral-current processes. They may also lead to strikingly large effects in high-energy accelerator experiments

Sterile neutrinos beyond LSND at the neutrino factory

International Nuclear Information System (INIS)

Meloni, Davide; Tang Jian; Winter, Walter

2010-01-01

We discuss the effects of one additional sterile neutrino at the Neutrino Factory. Compared to earlier analyses, which have been motivated by Liquid Scintillator Neutrino Detector (LSND) results, we do not impose any constraint on the additional mass squared splitting. This means that the additional mass eigenstate could, with small mixings, be located among the known ones, as it is suggested by the recent analysis of cosmological data. We use a self-consistent framework at the Neutrino Factory without any constraints on the new parameters. We demonstrate for a combined short and long baseline setup that near detectors can provide the expected sensitivity at the LSND-motivated Δm 41 2 -range, while some sensitivity can also be obtained in the region of the atmospheric mass splitting from the long baselines. We point out that limits on such very light sterile neutrinos may also be obtained from a reanalysis of atmospheric and solar neutrino oscillation data, as well as from supernova neutrino observations. In the second part of the analysis, we compare our sensitivity with the existing literature using additional assumptions, such as |Δm 41 2 |>>|Δm 31 2 |, leading to averaging of the fast oscillations in the far detectors. We demonstrate that while the Neutrino Factory has excellent sensitivity compared to existing studies using similar assumptions, one has to be very careful interpreting these results for a combined short and long baseline setup where oscillations could occur in the near detectors. We also test the impact of additional ν τ detectors at the short and long baselines, and we do not find a substantial improvement of the sensitivities.

ABSOLUTE NEUTRINO MASSES

DEFF Research Database (Denmark)

Schechter, J.; Shahid, M. N.

2012-01-01

We discuss the possibility of using experiments timing the propagation of neutrino beams over large distances to help determine the absolute masses of the three neutrinos.......We discuss the possibility of using experiments timing the propagation of neutrino beams over large distances to help determine the absolute masses of the three neutrinos....

Workshop: Neutrino telescopes

International Nuclear Information System (INIS)

Anon.

1990-01-01

Despite being the most elusive of the known particles, neutrinos provide vital new physics insights. Most neutrino knowledge so far has come from studies using beams from reactors and accelerators, but in recent years important new contributions have resulted from investigation of natural neutrinos from cosmic rays, nearby stars (the sun), or distant sources, such as the 1987 supernova. The supernova observations marked the start of a new era in neutrino astronomy, but neutrino telescopes were anyway assured of an important ongoing role

Workshop: Neutrino telescopes

Energy Technology Data Exchange (ETDEWEB)

Anon.

1990-05-15

Despite being the most elusive of the known particles, neutrinos provide vital new physics insights. Most neutrino knowledge so far has come from studies using beams from reactors and accelerators, but in recent years important new contributions have resulted from investigation of natural neutrinos from cosmic rays, nearby stars (the sun), or distant sources, such as the 1987 supernova. The supernova observations marked the start of a new era in neutrino astronomy, but neutrino telescopes were anyway assured of an important ongoing role.

Relic density and CMB constraints on dark matter annihilation with Sommerfeld enhancement

International Nuclear Information System (INIS)

Zavala, Jesus; White, Simon D. M.; Vogelsberger, Mark

2010-01-01

We calculate how the relic density of dark matter particles is altered when their annihilation is enhanced by the Sommerfeld mechanism due to a Yukawa interaction between the annihilating particles. Maintaining a dark matter abundance consistent with current observational bounds requires the normalization of the s-wave annihilation cross section to be decreased compared to a model without enhancement. The level of suppression depends on the specific parameters of the particle model, with the kinetic decoupling temperature having the most effect. We find that the cross section can be reduced by as much as an order of magnitude for extreme cases. We also compute the μ-type distortion of the CMB energy spectrum caused by energy injection from such Sommerfeld-enhanced annihilation. Our results indicate that in the vicinity of resonances, associated with bound states, distortions can be large enough to be excluded by the upper limit |μ|≤9.0x10 -5 found by the FIRAS (Far Infrared Absolute Spectrophotometer) instrument on the COBE (Cosmic Background Explorer) satellite.

A model for pseudo-Dirac neutrinos: leptogenesis and ultra-high energy neutrinos

Energy Technology Data Exchange (ETDEWEB)

Ahn, Y.H. [Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS),Daejeon, 34051 (Korea, Republic of); Kang, Sin Kyu [Insitute for Convergence Fundamental Study, School of Liberal Arts, Seoul-Tech.,Seoul, 01811 (Korea, Republic of); Kim, C.S. [Dept. of Physics and IPAP, Yonsei University,Seoul, 120-749 (Korea, Republic of)

2016-10-18

We propose a model where sterile neutrinos are introduced to make light neutrinos to be pseudo-Dirac particles. It is shown how tiny mass splitting necessary for realizing pseudo-Dirac neutrinos can be achieved. Within the model, we show how leptogenesis can be successfully generated. Motivated by the recent observation of very high energy neutrino events at IceCube, we study a possibility to observe the effects of the pseudo-Dirac property of neutrinos by performing astronomical-scale baseline experiments to uncover the oscillation effects of very tiny mass splitting. We also discuss future prospect to observe the effects of the pseudo-Dirac property of neutrinos at high energy neutrino experiments.

Constraining the mSUGRA parameter space through entropy and abundance criteria

International Nuclear Information System (INIS)

Cabral-Rosetti, Luis G.; Mondragon, Myriam; Nunez, Dario; Sussman, Roberto A.; Zavala, Jesus; Nellen, Lukas

2007-01-01

We explore the use of two criteria to constrain the allowed parameter space in mSUGRA models; both criteria are based in the calculation of the present density of neutralinos χ0 as Dark Matter in the Universe. The first one is the usual ''abundance'' criterion that requieres that present neutralino relic density complies with 0.0945 < ΩCDMh2 < 0.1287, which are the 2σ bounds according to WMAP. To calculate the relic density we use the public numerical code micrOMEGAS. The second criterion is the original idea presented in [3] that basically applies the microcanonical definition of entropy to a weakly interacting and self-gravitating gas, and then evaluate the change in entropy per particle of this gas between the freeze-out era and present day virialized structures. An 'entropy consistency' criterion emerges by comparing theoretical and empirical estimates of this entropy. One of the objetives of the work is to analyze the joint application of both criteria, already done in [3], to see if their results, using approximations for the calculations of the relic density, agree with the results coming from the exact numerical results of micrOMEGAS. The main objetive of the work is to use this method to constrain the parameter space in mSUGRA models that are inputs for the calculations of micrOMEGAS, and thus to get some bounds on the predictions for the SUSY spectra

Relic gravitational waves and extended inflation

International Nuclear Information System (INIS)

Turner, M.S.; Wilczek, F.

1990-01-01

In extended inflation, a new version of inflation where the transition from an inflationary to a radiation-dominated Universe is accomplished by bubble nucleation, bubble collisions supply a potent---and potentially detectable---source of gravitational waves. The energy density in relic gravitons from bubble collisions is expected to be about 10 -5 of closure density. Their characteristic wavelength depends upon the reheating temperature T RH: λ∼(10 4 cm)[(10 14 GeV)/T RH ]. If black holes are produced by bubble collisions, they will evaporate producing shorter-wavelength gravitons

The ideal neutrino beams

CERN Document Server

Lindroos, Mats

2009-01-01

The advance in neutrino oscillation physics is driven by the availability of well characterized and high flux neutrino beams. The three present options for the next generation neutrino oscillation facility are super beams, neutrino factories and beta-beams. A super-beam is a very high intensity classical neutrino beam generated by protons impinging on a target where the neutrinos are generated by the secondary particles decaying in a tunnel down streams of the target. In a neutrino factory the neutrinos are generated from muons decaying in a storage ring with long straight sections pointing towards the detectors. In a beta-beam the neutrinos are also originating from decay in a storage ring but the decaying particles are radioactive ions rather than muons. I will in this presentation review the three options and discuss the pros and cons of each. The present joint design effort for a future high intensity neutrino oscillation in Europe within a common EU supported design study, EURONU, will also be presented....

50 years of neutrinos

CERN Document Server

Goldhaber, M

1980-01-01

On December 4 1930, Wolfgang Pauli addressed an "open letter" to Lise Meitner and others attending a physics meeting, suggesting the neutrino as a way out of the difficulties confronted in beta rays research, especially by the existence of a continuous beta spectrum. He proposed a new particle later called the neutrino. The prehistory leading up to Pauli's letter will be reviewed, as well as the later discovery of the electron-neutrino followed by the muon-neutrino. There are now believed to be three different types of neutrino and their anti-particles. Neutrinos have a spin 1/2; but only one spin component has been found in nature: neutrinos go forward as "left-handed" screws and anti-neutrinos as "right-handed" ones. A question still not convincingly resolved today is wether neutrinos have a mass different from zero and, if they do, what consequences this would have for the behaviour of neutrinos and for cosmology.

The solar neutrinos epopee

CERN Document Server

Lasserre, T

2003-01-01

The 2002 year has been fruitful for the neutrino physics. First, the Sudbury Neutrino Observatory (SNO) experiment has shown that the electron neutrinos nu sub e emitted by the sun are converted into muon neutrinos (nu submu) and tau neutrinos (nu subtau), thus closing the 30 years old problem of solar neutrinos deficit. This discovery validates the model of nuclear energy production inside the sun but it shakes the theory describing the weak interactions between the fundamental constituents of matter. This theory considers the neutrinos (and the photons) as massless particles, while the taste conversion phenomenon necessarily implies that neutrinos have a mass. In October 2000, the Universe exploration by the cosmic neutrinos is jointly recognized by R. Davis (USA) and M. Koshiba (Japan) who received the Nobel price of physics. Finally, in December 2000, the KamLAND experiment quantitatively demonstrated the neutrinos metamorphosis by detecting a deficit in the flux of electron antineutrinos coming from the ...

RELIC: a novel dye-bias correction method for Illumina Methylation BeadChip.

Science.gov (United States)

Xu, Zongli; Langie, Sabine A S; De Boever, Patrick; Taylor, Jack A; Niu, Liang

2017-01-03

The Illumina Infinium HumanMethylation450 BeadChip and its successor, Infinium MethylationEPIC BeadChip, have been extensively utilized in epigenome-wide association studies. Both arrays use two fluorescent dyes (Cy3-green/Cy5-red) to measure methylation level at CpG sites. However, performance difference between dyes can result in biased estimates of methylation levels. Here we describe a novel method, called REgression on Logarithm of Internal Control probes (RELIC) to correct for dye bias on whole array by utilizing the intensity values of paired internal control probes that monitor the two color channels. We evaluate the method in several datasets against other widely used dye-bias correction methods. Results on data quality improvement showed that RELIC correction statistically significantly outperforms alternative dye-bias correction methods. We incorporated the method into the R package ENmix, which is freely available from the Bioconductor website ( https://www.bioconductor.org/packages/release/bioc/html/ENmix.html ). RELIC is an efficient and robust method to correct for dye-bias in Illumina Methylation BeadChip data. It outperforms other alternative methods and conveniently implemented in R package ENmix to facilitate DNA methylation studies.

Abundances in galaxies

International Nuclear Information System (INIS)

Pagel, B.E.J.

1991-01-01

Standard (or mildly inhomogeneous) Big Bang nucleosynthesis theory is well confirmed by abundance measurements of light elements up to 7 Li and the resulting upper limit to the number of neutrino families confirmed in accelerator experiments. Extreme inhomogeneous models with a closure density in form of baryons seem to be ruled out and there is no evidence for a cosmic 'floor' to 9 Be or heavier elements predicted in some versions of those models. Galaxies show a correlation between luminous mass and abundance of carbon and heavier elements, usually attributed to escape of hot gas from shallow potential wells. Uncertainties include the role of dark matter and biparametric behaviour of ellipticals. Spirals have radial gradients which may arise from a variety of causes. In our own Galaxy one can distinguish three stellar populations - disk, halo and bulge - characterised by differing metallicity distribution functions. Differential abundance effects are found among different elements in stars as a function of metallicity and presumably age, notably in the ratio of oxygen and α-particle elements to iron. These may eventually be exploitable to set a time scale for the formation of the halo, bulge and disk. (orig.)

Neutrino 2004: Collection of Presentations

International Nuclear Information System (INIS)

2004-01-01

The scientific program covers the latest developments in neutrino physics, astrophysics and related topics through a set of invited talks and 2 poster sessions. The following issues are addressed: - solar neutrinos, - atmospheric neutrinos, - short and long baseline experiments, - neutrino oscillations, - double beta decay, - direct neutrino mass limits, - theory for neutrino masses, neutrino telescopes and ultra-high energy neutrinos, - dark matter searches, - neutrino in astrophysics and cosmology, and - future projects beams and experiments

Neutrino 2004: Collection of Presentations

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

The scientific program covers the latest developments in neutrino physics, astrophysics and related topics through a set of invited talks and 2 poster sessions. The following issues are addressed: - solar neutrinos, - atmospheric neutrinos, - short and long baseline experiments, - neutrino oscillations, - double beta decay, - direct neutrino mass limits, - theory for neutrino masses, neutrino telescopes and ultra-high energy neutrinos, - dark matter searches, - neutrino in astrophysics and cosmology, and - future projects beams and experiments.

Neutrino oscillations and the seesaw origin of neutrino mass

Energy Technology Data Exchange (ETDEWEB)

Miranda, O.G., E-mail: omr@fis.cinvestav.mx [Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740, 07000 Mexico, Distrito Federal (Mexico); Valle, J.W.F. [AHEP Group, Institut de Física Corpuscular – C.S.I.C./Universitat de València, Parc Cientific de Paterna, C/Catedratico José Beltrán, 2, E-46980 Paterna (València) (Spain)

2016-07-15

The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.

Cold dark matter plus not-so-clumpy dark relics

International Nuclear Information System (INIS)

Diamanti, Roberta; Ando, Shin'ichiro; Weniger, Christoph; Gariazzo, Stefano; Mena, Olga

2017-01-01

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f ncdm of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2σ limits for non-cold dark matter particles with masses in the range 1–10 keV are f ncdm ≤0.29 (0.23) for fermions (bosons), and for masses in the 10–100 keV range they are f ncdm ≤0.43 (0.45), respectively.

Cold dark matter plus not-so-clumpy dark relics

Energy Technology Data Exchange (ETDEWEB)

Diamanti, Roberta; Ando, Shin' ichiro; Weniger, Christoph [GRAPPA, Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Gariazzo, Stefano; Mena, Olga, E-mail: r.diamanti@uva.nl, E-mail: s.ando@uva.nl, E-mail: gariazzo@to.infn.it, E-mail: omena@ific.uv.es, E-mail: c.weniger@uva.nl [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de Valencia, Apartado de Correos 22085, E-46071, Valencia (Spain)

2017-06-01

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f {sub ncdm} of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2σ limits for non-cold dark matter particles with masses in the range 1–10 keV are f {sub ncdm}≤0.29 (0.23) for fermions (bosons), and for masses in the 10–100 keV range they are f {sub ncdm}≤0.43 (0.45), respectively.

Neutrinos from WIMP annihilations in the Sun including neutrino oscillations

International Nuclear Information System (INIS)

Blennow, Mattias; Edsjö, Joakim; Ohlsson, Tommy

2011-01-01

The prospects to detect neutrinos from the Sun arising from dark matter annihilations in the core of the Sun are reviewed. Emphasis is placed on new work investigating the effects of neutrino oscillations on the expected neutrino fluxes.

Neutrinos from WIMP annihilations in the Sun including neutrino oscillations

International Nuclear Information System (INIS)

Blennow, Mattias; Edsjoe, Joakim; Ohlsson, Tommy

2006-01-01

The prospects for detecting neutrinos from the Sun arising from dark matter annihilations in the core of the Sun are reviewed. Emphasis is placed on new work investigating the effects of neutrino oscillations on the expected neutrino fluxes

Identifying the neutrino mass spectrum from a supernova neutrino burst

International Nuclear Information System (INIS)

Dighe, A.S.; Smirnov, A.Yu.

1999-12-01

We study the role that the future detection of the neutrino burst from a galactic supernova can play in the reconstruction of the neutrino mass spectrum. We consider all possible 3ν mass and flavor spectra which describe the solar and atmospheric neutrino data. For each of these spectra we find the observable effects of the supernova neutrino conversions both in the matter of the star and the earth. We show that studies of the electron neutrino and antineutrino spectra as well as observations of the neutral current effects from supernova will allow us (i) to identify the solar neutrino solution, (ii) to determine the type of mass hierarchy (normal or inverted) and (iii) to probe the mixing vertical bar U e3 vertical bar 2 to values as low as 10 -4 - 10 -3 . (author)

Determination of the atmospheric neutrino fluxes from atmospheric neutrino data

International Nuclear Information System (INIS)

Gonzalez-Garcia, C.; Maltoni, M.; Rojo, J.

2006-06-01

The precise knowledge of the atmospheric neutrino fluxes is a key ingredient in the interpretation of the results from any atmospheric neutrino experiment. In the standard data analysis, these fluxes are theoretical inputs obtained from sophisticated numerical calculations based on the convolution of the primary cosmic ray spectrum with the expected yield of neutrinos per incident cosmic ray. In this work we present an alternative approach to the determination of the atmospheric neutrino fluxes based on the direct extraction from the experimental data on neutrino event rates. The extraction is achieved by means of a combination of artificial neural networks as interpolants and Monte Carlo methods for faithful error estimation. (author)

Determination of the atmospheric neutrino fluxes from atmospheric neutrino data

International Nuclear Information System (INIS)

Gonzalez-Garcia, Concepcion; Maltoni, Michele; Rojo, Joan

2006-01-01

The precise knowledge of the atmospheric neutrino fluxes is a key ingredient in the interpretation of the results from any atmospheric neutrino experiment. In the standard data analysis, these fluxes are theoretical inputs obtained from sophisticated numerical calculations based on the convolution of the primary cosmic ray spectrum with the expected yield of neutrinos per incident cosmic ray. In this work we present an alternative approach to the determination of the atmospheric neutrino fluxes based on the direct extraction from the experimental data on neutrino event rates. The extraction is achieved by means of a combination of artificial neural networks as interpolants and Monte Carlo methods for faithful error estimation

Neutrinos and dark energy

International Nuclear Information System (INIS)

Schrempp, L.

2008-02-01

From the observed late-time acceleration of cosmic expansion arises the quest for the nature of Dark Energy. As has been widely discussed, the cosmic neutrino background naturally qualifies for a connection with the Dark Energy sector and as a result could play a key role for the origin of cosmic acceleration. In this thesis we explore various theoretical aspects and phenomenological consequences arising from non-standard neutrino interactions, which dynamically link the cosmic neutrino background and a slowly-evolving scalar field of the dark sector. In the considered scenario, known as Neutrino Dark Energy, the complex interplay between the neutrinos and the scalar field not only allows to explain cosmic acceleration, but intriguingly, as a distinct signature, also gives rise to dynamical, time-dependent neutrino masses. In a first analysis, we thoroughly investigate an astrophysical high energy neutrino process which is sensitive to neutrino masses. We work out, both semi-analytically and numerically, the generic clear-cut signatures arising from a possible time variation of neutrino masses which we compare to the corresponding results for constant neutrino masses. Finally, we demonstrate that even for the lowest possible neutrino mass scale, it is feasible for the radio telescope LOFAR to reveal a variation of neutrino masses and therefore to probe the nature of Dark Energy within the next decade. A second independent analysis deals with the recently challenged stability of Neutrino Dark Energy against the strong growth of hydrodynamic perturbations, driven by the new scalar force felt between neutrinos. Within the framework of linear cosmological perturbation theory, we derive the equation of motion of the neutrino perturbations in a model-independent way. This equation allows to deduce an analytical stability condition which translates into a comfortable upper bound on the scalar-neutrino coupling which is determined by the ratio of the densities in cold dark

Neutrinos and dark energy

Energy Technology Data Exchange (ETDEWEB)

Schrempp, L.

2008-02-15

From the observed late-time acceleration of cosmic expansion arises the quest for the nature of Dark Energy. As has been widely discussed, the cosmic neutrino background naturally qualifies for a connection with the Dark Energy sector and as a result could play a key role for the origin of cosmic acceleration. In this thesis we explore various theoretical aspects and phenomenological consequences arising from non-standard neutrino interactions, which dynamically link the cosmic neutrino background and a slowly-evolving scalar field of the dark sector. In the considered scenario, known as Neutrino Dark Energy, the complex interplay between the neutrinos and the scalar field not only allows to explain cosmic acceleration, but intriguingly, as a distinct signature, also gives rise to dynamical, time-dependent neutrino masses. In a first analysis, we thoroughly investigate an astrophysical high energy neutrino process which is sensitive to neutrino masses. We work out, both semi-analytically and numerically, the generic clear-cut signatures arising from a possible time variation of neutrino masses which we compare to the corresponding results for constant neutrino masses. Finally, we demonstrate that even for the lowest possible neutrino mass scale, it is feasible for the radio telescope LOFAR to reveal a variation of neutrino masses and therefore to probe the nature of Dark Energy within the next decade. A second independent analysis deals with the recently challenged stability of Neutrino Dark Energy against the strong growth of hydrodynamic perturbations, driven by the new scalar force felt between neutrinos. Within the framework of linear cosmological perturbation theory, we derive the equation of motion of the neutrino perturbations in a model-independent way. This equation allows to deduce an analytical stability condition which translates into a comfortable upper bound on the scalar-neutrino coupling which is determined by the ratio of the densities in cold dark

Neutrino-Electron Scattering in MINERvA for Constraining the NuMI Neutrino Flux

Energy Technology Data Exchange (ETDEWEB)

Park, Jaewon [Univ. of Rochester, NY (United States)

2013-01-01

Neutrino-electron elastic scattering is used as a reference process to constrain the neutrino flux at the Main Injector (NuMI) beam observed by the MINERvA experiment. Prediction of the neutrino flux at accelerator experiments from other methods has a large uncertainty, and this uncertainty degrades measurements of neutrino oscillations and neutrino cross-sections. Neutrino-electron elastic scattering is a rare process, but its cross-section is precisely known. With a sample corresponding to $3.5\\times10^{20}$ protons on target in the NuMI low-energy neutrino beam, a sample of $120$ $\

Determination of the Atmospheric Neutrino Fluxes from Atmospheric Neutrino Data

NARCIS (Netherlands)

Gonzalez-Garcia, M. C.; Maltoni, M.; Rojo, J.

2006-01-01

The precise knowledge of the atmospheric neutrino fluxes is a key ingredient in the interpretation of the results from any atmospheric neutrino experiment. In the standard atmospheric neutrino data analysis, these fluxes are theoretical inputs obtained from sophisticated numerical calculations based

Neutrinos in Nuclear Physics

Energy Technology Data Exchange (ETDEWEB)

McKeown, Bob [bmck@jlab.org

2015-06-01

Since the discovery of nuclear beta decay, nuclear physicists have studied the weak interaction and the nature of neutrinos. Many recent and current experiments have been focused on the elucidation of neutrino oscillations and neutrino mass. The quest for the absolute value of neutrino mass continues with higher precision studies of the tritium beta decay spectrum near the endpoint. Neutrino oscillations are studied through measurements of reactor neutrinos as a function of baseline and energy. And experiments searching for neutrinoless double beta decay seek to discover violation of lepton number and establish the Majorana nature of neutrino masses.

Future neutrino experiments

CERN Document Server

Di Lella, L

2001-01-01

Future experiments to search for neutrino oscillations using neutrinos from the Sun, from reactors and accelerators are reviewed. Possible long-term developments based on neutrino factories are also described. (29 refs).

Right-handed neutrinos at CERN LHC and the mechanism of neutrino mass generation

International Nuclear Information System (INIS)

Kersten, Joern; Smirnov, Alexei Yu.

2007-01-01

We consider the possibility to detect right-handed neutrinos, which are mostly singlets of the standard model gauge group, at future accelerators. Substantial mixing of these neutrinos with the active neutrinos requires a cancellation of different contributions to the light neutrino mass matrix at the level of 10 -8 . We discuss possible symmetries behind this cancellation and argue that for three right-handed neutrinos they always lead to conservation of total lepton number. Light neutrino masses can be generated by small perturbations violating these symmetries. In the most general case, LHC physics and the mechanism of neutrino mass generation are essentially decoupled; with additional assumptions, correlations can appear between collider observables and features of the neutrino mass matrix

Superpixel segmentation and pigment identification of colored relics based on visible spectral image

Science.gov (United States)

Li, Junfeng; Wan, Xiaoxia

2018-01-01

To enrich the contents of digital archive and to guide the copy and restoration of colored relics, non-invasive methods for extraction of painting boundary and identification of pigment composition are proposed in this study based on the visible spectral images of colored relics. Superpixel concept is applied for the first time to the field of oversegmentation of visible spectral images and implemented on the visible spectral images of colored relics to extract their painting boundary. Since different pigments are characterized by their own spectrum and the same kind of pigment has the similar geometric profile in spectrum, an automatic identification method is established by comparing the proximity between the geometric profiles of the unknown spectrum from each superpixel and the pre-known spectrum from a deliberately prepared database. The methods are validated using the visible spectral images of the ancient wall paintings in Mogao Grottoes. By the way, the visible spectral images are captured by a multispectral imaging system consisting of two broadband filters and a RGB camera with high spatial resolution.

Asymmetric dark matter and the Sun

DEFF Research Database (Denmark)

Frandsen, Mads Toudal; Sarkar, Subir

2010-01-01

Cold dark matter particles with an intrinsic matter-antimatter asymmetry do not annihilate after gravitational capture by the Sun and can affect its interior structure. The rate of capture is exponentially enhanced when such particles have self-interactions of the right order to explain structure...... formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural candidate and has the required relic abundance if its asymmetry is similar to that of ordinary baryons. We show that such particles can solve the `solar composition problem'. The predicted small decrease in the low energy neutrino...

Constraining neutrino magnetic moment with solar and reactor neutrino data

OpenAIRE

Tortola, M. A.

2004-01-01

We use solar neutrino data to derive stringent bounds on Majorana neutrino transition moments (TMs). Such moments, if present, would contribute to the neutrino-electron scattering cross section and hence alter the signal observed in Super-Kamiokande. Using the latest solar neutrino data, combined with the results of the reactor experiment KamLAND, we perform a simultaneous fit of the oscillation parameters and TMs. Furthermore, we include data from the reactor experiments Rovno, TEXONO and MU...

When neutrinos attack - the impact of agressive neutrinos in astrophysics.

Science.gov (United States)

Kneller, James

2004-11-01

Of all the constituents within the standard model of particle physics our understanding of the neutrino has benefited the most from the interaction of astrophysics and `terraphysics'. Much has been learned about the properties of the neutrino from each: experiments here on Earth temper our appreciation of the role that neutrinos play in the cosmos while astrophysics can provide the densities and temperatures in which the neutrinos do more than simply flee. But their reluctance to interact means that it is not until we venture into the most extreme environments of astrophysics that we observe neutrinos pushing back' as hard as they are being pushed'. We review two sites where this occurs: the early Universe and the accretion disk, engines' of gamma ray bursts. Neutrinos play an important role in the evolution of the early Universe with a particular focus upon the electron neutrino in determining the primordial elemental composition via its participation in the most important reaction at that time. Within gamma ray burst accretion disks we again see the electron neutrinos at work in the nuclear reactions and through their function as the coolant' for the disk. Removal of the disk energy, and its deposition into the remnants of the massive star surrounding the disk, may lead to the formation of highly relativistic jets that will later be observed as the burst. We show what has been learned so far about the neutrino and its properties from the study of such environments and discuss where future research is heading.

Effects of neutrino oscillation on supernova neutrino. Inverted mass hierarchy

International Nuclear Information System (INIS)

Takahashi, Keitaro; Sato, Katsuhiko

2003-01-01

We study the effects of neutrino oscillation on supernova neutrinos in the case of the inverted mass hierarchy (m 3 1 2 ) as well as the normal mass hierarchy (m 1 2 3 ). Numerical analysis using realistic supernova and presupernova models allows us to investigate quantitatively the possibility to probe neutrino oscillation parameters. We show that information about the mass hierarchy can be obtained if θ 13 is rather large (sin 2 2θ 13 > 10 -3 ) and that θ 13 can be probed effectively by SuperKamiokande if the neutrino mass hierarchy is inverted. Errors due to the uncertainty in the original neutrino spectra and the Earth effect are also discussed. (author)

Radiative neutrino mass model with degenerate right-handed neutrinos

International Nuclear Information System (INIS)

Kashiwase, Shoichi; Suematsu, Daijiro

2016-01-01

The radiative neutrino mass model can relate neutrino masses and dark matter at a TeV scale. If we apply this model to thermal leptogenesis, we need to consider resonant leptogenesis at that scale. It requires both finely degenerate masses for the right-handed neutrinos and a tiny neutrino Yukawa coupling. We propose an extension of the model with a U(1) gauge symmetry, in which these conditions are shown to be simultaneously realized through a TeV scale symmetry breaking. Moreover, this extension can bring about a small quartic scalar coupling between the Higgs doublet scalar and an inert doublet scalar which characterizes the radiative neutrino mass generation. It also is the origin of the Z 2 symmetry which guarantees the stability of dark matter. Several assumptions which are independently supposed in the original model are closely connected through this extension. (orig.)

Homestake result, sterile neutrinos, and low energy solar neutrino experiments

Science.gov (United States)

de Holanda, P. C.; Smirnov, A. Yu.

2004-06-01

The Homestake result is about ˜2σ lower than the Ar-production rate, QAr, predicted by the large mixing angle (LMA) Mikheyev-Smirnov-Wolfenstein solution of the solar neutrino problem. Also there is no apparent upturn of the energy spectrum (R≡Nobs/NSSM) at low energies in SNO and Super-Kamiokande. Both these facts can be explained if a light, Δm201˜(0.2 2)×10-5 eV2, sterile neutrino exists which mixes very weakly with active neutrinos: sin2 2α˜(10-5 10-3). We perform both the analytical and numerical study of the conversion effects in the system of two active neutrinos with the LMA parameters and one weakly mixed sterile neutrino. The presence of sterile neutrino leads to a dip in the survival probability in the intermediate energy range E=(0.5 5) MeV thus suppressing the Be, or/and pep, CNO, as well as B electron neutrino fluxes. Apart from diminishing QAr it leads to decrease of the Ge-production rate and may lead to the decrease of the BOREXINO signal as well as the CC/NC ratio at SNO. Future studies of the solar neutrinos by SNO, SK, BOREXINO, and KamLAND as well as by the new low energy experiments will allow us to check this possibility.

Introduction to massive neutrinos

International Nuclear Information System (INIS)

Kayser, B.

1984-01-01

We discuss the theoretical ideas which make it natural to expect that neutrinos do indeed have mass. Then we focus on the physical consequences of neutrino mass, including neutrino oscillation and other phenomena whose observation would be very interesting, and would serve to demonstrate that neutrinos are indeed massive. We comment on the legitimacy of comparing results from different types of experiments. Finally, we consider the question of whether neutrinos are their own antiparticles. We explain what this question means, discuss the nature of a neutrino which is its own antiparticles, and consider how one might determine experimentally whether neutrinos are their own antiparticles or not

Solar neutrino detection

International Nuclear Information System (INIS)

Miramonti, Lino

2009-01-01

More than 40 years ago, neutrinos where conceived as a way to test the validity of the solar models which tell us that stars are powered by nuclear fusion reactions. The first measurement of the neutrino flux, in 1968 in the Homestake mine in South Dakota, detected only one third of the expected value, originating what has been known as the Solar Neutrino Problem. Different experiments were built in order to understand the origin of this discrepancy. Now we know that neutrinos undergo oscillation phenomenon changing their nature traveling from the core of the Sun to our detectors. In the work the 40 year long saga of the neutrino detection is presented; from the first proposals to test the solar models to last real time measurements of the low energy part of the neutrino spectrum.

Molybdenum solar neutrino experiment

International Nuclear Information System (INIS)

Wolfsberg, K.; Cowan, G.A.; Bryant, E.A.

1984-01-01

The goal of the molybdenum solar neutrino experiment is to deduce the 8 B solar neutrino flux, averaged over the past several million years, from the concentration of 98 Tc in a deeply buried molybdenum deposit. The experiment is important to an understanding of stellar processes because it will shed light on the reason for the discrepancy between theory and observation of the chlorine solar neutrino experiment. Possible reasons for the discrepancy may lie in the properties of neutrinos (neutrino oscillations or massive neutrinos) or in deficiencies of the standard solar model. The chlorine experiment only measures the 8 B neutrino flux in current times and does not address possible temporal variations in the interior of the sun, which are also not considered in the standard model. In the molybdenum experiment, we plan to measure 98 Tc (4.2 Myr), also produced by 8 B neutrinos, and possibly 97 Tc (2.6 Myr), produced by lower energy neutrinos

The physics of neutrinos

CERN Document Server

Barger, Vernon D; Whisnant, Kerry

2012-01-01

The physics of neutrinos- uncharged elementary particles that are key to helping us better understand the nature of our universe - is one of the most exciting frontiers of modern science. This book provides a comprehensive overview of neutrino physics today and explores promising new avenues of inquiry that could lead to future breakthroughs. The Physics of Neutrinos begins with a concise history of the field and a tutorial on the fundamental properties of neutrinos, and goes on to discuss how the three neutrino types interchange identities as they propagate from their sources to detectors. The book shows how studies of neutrinos produced by such phenomena as cosmic rays in the atmosphere and nuclear reactions in the solar interior provide striking evidence that neutrinos have mass, and it traces our astounding progress in deciphering the baffling experimental findings involving neutrinos. The discovery of neutrino mass offers the first indication of a new kind of physics that goes beyond the Standard Model ...

Decays of supernova neutrinos

International Nuclear Information System (INIS)

Lindner, Manfred; Ohlsson, Tommy; Winter, Walter

2002-01-01

Supernova neutrinos could be well-suited for probing neutrino decay, since decay may be observed even for very small decay rates or coupling constants. We will introduce an effective operator framework for the combined description of neutrino decay and neutrino oscillations for supernova neutrinos, which can especially take into account two properties: one is the radially symmetric neutrino flux, allowing a decay product to be re-directed towards the observer even if the parent neutrino had a different original direction of propagation. The other is decoherence because of the long baselines for coherently produced neutrinos. We will demonstrate how to use this effective theory to calculate the time-dependent fluxes at the detector. In addition, we will show the implications of a Majoron-like decay model. As a result, we will demonstrate that for certain parameter values one may observe some effects which could also mimic signals similar to the ones expected from supernova models, making it in general harder to separate neutrino and supernova properties

Case for neutrino oscillations

International Nuclear Information System (INIS)

Ramond, P.

1982-01-01

The building of a machine capable of producing an intense, well-calibrated beam of muon neutrinos is regarded by particle physicists with keen interest because of its ability of studying neutrino oscillations. The possibility of neutrino oscillations has long been recognized, but it was not made necessary on theoretical or experimental grounds; one knew that oscillations could be avoided if neutrinos were massless, and this was easily done by the conservation of lepton number. The idea of grand unification has led physicists to question the existence (at higher energies) of global conservation laws. The prime examples are baryon-number conservation, which prevents proton decay, and lepton-number conservation, which keeps neutrinos massless, and therefore free of oscillations. The detection of proton decay and neutrino oscillations would therefore be an indirect indication of the idea of Grand Unification, and therefore of paramount importance. Neutrino oscillations occur when neutrinos acquire mass in such a way that the neutrino mass eigenstates do not match the (neutrino) eigenstates produced by the weak interactions. We shall study the ways in which neutrinos can get mass, first at the level of the standard SU 2 x U 1 model, then at the level of its Grand Unification Generalizations

Quantum state correction of relic gravitons from quantum gravity

OpenAIRE

Rosales, Jose-Luis

1996-01-01

The semiclassical approach to quantum gravity would yield the Schroedinger formalism for the wave function of metric perturbations or gravitons plus quantum gravity correcting terms in pure gravity; thus, in the inflationary scenario, we should expect correcting effects to the relic graviton (Zel'dovich) spectrum of the order (H/mPl)^2.

A search for oscillations of muon-neutrinos to electron-neutrinos

CERN Document Server

Procario, Michael

1986-01-01

The author has searched in the heavy liquid bubble chamber BEBC for electron neutrino charge current events which could arise from oscillation of the muon neutrinos (average energy ∼1.5 GeV) obtained with a low energy proton beam at the CERN PS targeted 825 m upstream from BEBC. The appearance of electron neutrino CC interactions provides a sensitive indication of nu/sub μ/ → nu/sub e/ oscillation. The author observed 460 muon neutrino CC events and 4 electron neutrino CC events with an estimated background of 3.5 electron neutrino CC events. Using the likelihood ratio method to test the oscillation hypothesis, the author finds no evidence for nu/sub μ/ → nu/sub e/ oscillation and set the limits δm2 ≤ 0.13 eV2 (maximal mixing) and sin22theta ≤ 0.018 for δm2 = 3 eV2 at 90% confidence level

MINOS Sterile Neutrino Search

Energy Technology Data Exchange (ETDEWEB)

Koskinen, David Jason [Univ. College London, Bloomsbury (United Kingdom)

2009-02-01

The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline accelerator neutrino experiment designed to measure properties of neutrino oscillation. Using a high intensity muon neutrino beam, produced by the Neutrinos at Main Injector (NuMI) complex at Fermilab, MINOS makes two measurements of neutrino interactions. The first measurement is made using the Near Detector situated at Fermilab and the second is made using the Far Detector located in the Soudan Underground laboratory in northern Minnesota. The primary goal of MINOS is to verify, and measure the properties of, neutrino oscillation between the two detectors using the v _μ→ V_τ transition. A complementary measurement can be made to search for the existence of sterile neutrinos; an oft theorized, but experimentally unvalidated particle. The following thesis will show the results of a sterile neutrino search using MINOS RunI and RunII data totaling ~2.5 x 10²⁰ protons on target. Due to the theoretical nature of sterile neutrinos, complete formalism that covers transition probabilities for the three known active states with the addition of a sterile state is also presented.

Neutrino mass spectrum with υμ → υs oscillations of atmospheric neutrinos

International Nuclear Information System (INIS)

Liu, Q.Y.; Smirnov, A.Yu.

1998-02-01

We consider the ''standard'' spectrum of the active neutrinos (characterized by strong mass hierarchy and small mixing) with additional sterile, υ s . The sterile neutrino mixes strongly with the muon neutrino, so that υ μ ↔ υ s oscillations solve the atmospheric neutrino problem. We show that the parametric enhancement of the υ μ ↔ υ s oscillations occurs for the high energy atmospheric neutrinos which cross the core of the Earth. This can be relevant for the anomaly observed by the MACRO experiment. Solar neutrinos are converted both to υ μ and υ s . The heaviest neutrino (approx. υ τ ) may compose the hot dark matter of the Universe. Phenomenology of this scenario is elaborated and crucial experimental signatures are identified. We also discuss properties of the underlying neutrino mass matrix. (author)

Sudbury neutrino observatory

International Nuclear Information System (INIS)

Ewan, G.T.; Mak, H.B.; Robertson, B.C.

1985-07-01

This report discusses the proposal to construct a unique neutrino observatory. The observatory would contain a Cerenkov detector which would be located 2070 m below the earth's surface in an INCO mine at Creighton near Sudbury and would contain 1000 tons of D20 which is an excellent target material. Neutrinos carry detailed information in their spectra on the reactions taking place deep in the interstellar interior and also provide information on supernova explosions. In addition to their role as astrophysical probes a knowledge of the properties of neutrinos is crucial to theories of grand unification. There are three main objectives of the laboratory. The prime objective will be to study B electron neutrinos from the sun by a direct counting method that will measure their energy and direction. The second major objective will be to establish if electron neutrinos change into other neutrino species in transit from the sun to the earth. Finally it is hoped to be able to observe a supernova with the proposed detector. The features of the Sudbury Neutrino Observatory which make it unique are its high sensitivity to electron neutrinos and its ability to detect all other types of neutrinos of energy greater than 2.2 MeV. In section II of this proposal the major physics objectives are discussed in greater detail. A conceptual design for the detector, and measurements and calculations which establish the feasibility of the neutrino experiments are presented in section III. Section IV is comprised of a discussion on the possible location of the laboratory and Section V contains a brief indication of the main areas to be studied in Phase II of the design study

Neutrino physics with JUNO

Science.gov (United States)

An, Fengpeng; An, Guangpeng; An, Qi; Antonelli, Vito; Baussan, Eric; Beacom, John; Bezrukov, Leonid; Blyth, Simon; Brugnera, Riccardo; Buizza Avanzini, Margherita; Busto, Jose; Cabrera, Anatael; Cai, Hao; Cai, Xiao; Cammi, Antonio; Cao, Guofu; Cao, Jun; Chang, Yun; Chen, Shaomin; Chen, Shenjian; Chen, Yixue; Chiesa, Davide; Clemenza, Massimiliano; Clerbaux, Barbara; Conrad, Janet; D'Angelo, Davide; De Kerret, Hervé; Deng, Zhi; Deng, Ziyan; Ding, Yayun; Djurcic, Zelimir; Dornic, Damien; Dracos, Marcos; Drapier, Olivier; Dusini, Stefano; Dye, Stephen; Enqvist, Timo; Fan, Donghua; Fang, Jian; Favart, Laurent; Ford, Richard; Göger-Neff, Marianne; Gan, Haonan; Garfagnini, Alberto; Giammarchi, Marco; Gonchar, Maxim; Gong, Guanghua; Gong, Hui; Gonin, Michel; Grassi, Marco; Grewing, Christian; Guan, Mengyun; Guarino, Vic; Guo, Gang; Guo, Wanlei; Guo, Xin-Heng; Hagner, Caren; Han, Ran; He, Miao; Heng, Yuekun; Hsiung, Yee; Hu, Jun; Hu, Shouyang; Hu, Tao; Huang, Hanxiong; Huang, Xingtao; Huo, Lei; Ioannisian, Ara; Jeitler, Manfred; Ji, Xiangdong; Jiang, Xiaoshan; Jollet, Cécile; Kang, Li; Karagounis, Michael; Kazarian, Narine; Krumshteyn, Zinovy; Kruth, Andre; Kuusiniemi, Pasi; Lachenmaier, Tobias; Leitner, Rupert; Li, Chao; Li, Jiaxing; Li, Weidong; Li, Weiguo; Li, Xiaomei; Li, Xiaonan; Li, Yi; Li, Yufeng; Li, Zhi-Bing; Liang, Hao; Lin, Guey-Lin; Lin, Tao; Lin, Yen-Hsun; Ling, Jiajie; Lippi, Ivano; Liu, Dawei; Liu, Hongbang; Liu, Hu; Liu, Jianglai; Liu, Jianli; Liu, Jinchang; Liu, Qian; Liu, Shubin; Liu, Shulin; Lombardi, Paolo; Long, Yongbing; Lu, Haoqi; Lu, Jiashu; Lu, Jingbin; Lu, Junguang; Lubsandorzhiev, Bayarto; Ludhova, Livia; Luo, Shu; Lyashuk, Vladimir; Möllenberg, Randolph; Ma, Xubo; Mantovani, Fabio; Mao, Yajun; Mari, Stefano M.; McDonough, William F.; Meng, Guang; Meregaglia, Anselmo; Meroni, Emanuela; Mezzetto, Mauro; Miramonti, Lino; Mueller, Thomas; Naumov, Dmitry; Oberauer, Lothar; Ochoa-Ricoux, Juan Pedro; Olshevskiy, Alexander; Ortica, Fausto; Paoloni, Alessandro; Peng, Haiping; Peng, Jen-Chieh; Previtali, Ezio; Qi, Ming; Qian, Sen; Qian, Xin; Qian, Yongzhong; Qin, Zhonghua; Raffelt, Georg; Ranucci, Gioacchino; Ricci, Barbara; Robens, Markus; Romani, Aldo; Ruan, Xiangdong; Ruan, Xichao; Salamanna, Giuseppe; Shaevitz, Mike; Sinev, Valery; Sirignano, Chiara; Sisti, Monica; Smirnov, Oleg; Soiron, Michael; Stahl, Achim; Stanco, Luca; Steinmann, Jochen; Sun, Xilei; Sun, Yongjie; Taichenachev, Dmitriy; Tang, Jian; Tkachev, Igor; Trzaska, Wladyslaw; van Waasen, Stefan; Volpe, Cristina; Vorobel, Vit; Votano, Lucia; Wang, Chung-Hsiang; Wang, Guoli; Wang, Hao; Wang, Meng; Wang, Ruiguang; Wang, Siguang; Wang, Wei; Wang, Yi; Wang, Yi; Wang, Yifang; Wang, Zhe; Wang, Zheng; Wang, Zhigang; Wang, Zhimin; Wei, Wei; Wen, Liangjian; Wiebusch, Christopher; Wonsak, Björn; Wu, Qun; Wulz, Claudia-Elisabeth; Wurm, Michael; Xi, Yufei; Xia, Dongmei; Xie, Yuguang; Xing, Zhi-zhong; Xu, Jilei; Yan, Baojun; Yang, Changgen; Yang, Chaowen; Yang, Guang; Yang, Lei; Yang, Yifan; Yao, Yu; Yegin, Ugur; Yermia, Frédéric; You, Zhengyun; Yu, Boxiang; Yu, Chunxu; Yu, Zeyuan; Zavatarelli, Sandra; Zhan, Liang; Zhang, Chao; Zhang, Hong-Hao; Zhang, Jiawen; Zhang, Jingbo; Zhang, Qingmin; Zhang, Yu-Mei; Zhang, Zhenyu; Zhao, Zhenghua; Zheng, Yangheng; Zhong, Weili; Zhou, Guorong; Zhou, Jing; Zhou, Li; Zhou, Rong; Zhou, Shun; Zhou, Wenxiong; Zhou, Xiang; Zhou, Yeling; Zhou, Yufeng; Zou, Jiaheng

2016-03-01

The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy (MH) as a primary physics goal. The excellent energy resolution and the large fiducial volume anticipated for the JUNO detector offer exciting opportunities for addressing many important topics in neutrino and astro-particle physics. In this document, we present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. Following an introduction summarizing the current status and open issues in neutrino physics, we discuss how the detection of antineutrinos generated by a cluster of nuclear power plants allows the determination of the neutrino MH at a 3-4σ significance with six years of running of JUNO. The measurement of antineutrino spectrum with excellent energy resolution will also lead to the precise determination of the neutrino oscillation parameters {{sin}}2{θ }12, {{Δ }}{m}212, and | {{Δ }}{m}{ee}2| to an accuracy of better than 1%, which will play a crucial role in the future unitarity test of the MNSP matrix. The JUNO detector is capable of observing not only antineutrinos from the power plants, but also neutrinos/antineutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, and solar neutrinos. As a result of JUNO's large size, excellent energy resolution, and vertex reconstruction capability, interesting new data on these topics can be collected. For example, a neutrino burst from a typical core-collapse supernova at a distance of 10 kpc would lead to ˜5000 inverse-beta-decay events and ˜2000 all-flavor neutrino-proton ES events in JUNO, which are of crucial importance for understanding the mechanism of supernova explosion and for exploring novel phenomena such as collective neutrino oscillations

Evidence for neutrino oscillations in the Sudbury Neutrino Observatory

International Nuclear Information System (INIS)

Marino, Alysia Diane

2004-01-01

The Sudbury Neutrino Observatory (SNO) is a large-volume heavy water Cerenkov detector designed to resolve the solar neutrino problem. SNO observes charged-current interactions with electron neutrinos, neutral-current interactions with all active neutrinos, and elastic-scattering interactions primarily with electron neutrinos with some sensitivity to other flavors. This dissertation presents an analysis of the solar neutrino flux observed in SNO in the second phase of operation, while ∼2 tonnes of salt (NaCl) were dissolved in the heavy water. The dataset here represents 391 live days of data. Only the events above a visible energy threshold of 5.5 MeV and inside a fiducial volume within 550 cm of the center of the detector are studied. The neutrino flux observed via the charged-current interaction is [1.71 ± 0.065(stat.)± 0.068 0.065 (sys.)±0.02(theor.)] x 10 6 cm -2 s -1 , via the elastic-scattering interaction is [2.21±0.22(stat.)± 0.12 0.11 (sys.)±0.01(theor.)] x 10 6 cm -2 s -1 , and via the neutral-current interaction is [5.05±0.23(stat.)± 0.37 0.31 (sys.)±0.06(theor.)] x 10 6 cm -2 s -1 . The electron-only flux seen via the charged-current interaction is more than 7σ below the total active flux seen via the neutral-current interaction, providing strong evidence that neutrinos are undergoing flavor transformation as they travel from the core of the Sun to the Earth. The most likely origin of the flavor transformation is matter-induced flavor oscillation

Frontiers in neutrino physics - Transparencies

International Nuclear Information System (INIS)

Akhmedov, E.; Balantekin, B.; Conrad, J.; Engel, J.; Fogli, G.; Giunti, C.; Espinoza, C.; Lasserre, T.; Lazauskas, R.; Lhuiller, D.; Lindner, M.; Martinez-Pinedo, G.; Martini, M.; McLaughlin, G.; Mirizzi, A.; Pehlivan, Y.; Petcov, S.; Qian, Y.; Serenelli, A.; Stancu, I.; Surman, R.; Vaananen, D.; Vissani, F.; Vogel, P.

2012-01-01

This document gathers the slides of the presentations. The purpose of the conference was to discuss the last advances in neutrino physics. The presentations dealt with: -) the measurement of the neutrino velocity, -) neutrino oscillations, -) anomaly in solar models and neutrinos, -) double beta decay, -) self refraction of neutrinos, -) cosmic neutrinos, -) antineutrino spectra from reactors, and -) some aspects of neutrino physics with radioactive ion beams. (A.C.)

Neutrino Oscillations Physics

Science.gov (United States)

Fogli, Gianluigi

2005-06-01

We review the status of the neutrino oscillations physics, with a particular emphasis on the present knowledge of the neutrino mass-mixing parameters. We consider first the νμ → ντ flavor transitions of atmospheric neutrinos. It is found that standard oscillations provide the best description of the SK+K2K data, and that the associated mass-mixing parameters are determined at ±1σ (and NDF = 1) as: Δm2 = (2.6 ± 0.4) × 10-3 eV2 and sin 2 2θ = 1.00{ - 0.05}{ + 0.00} . Such indications, presently dominated by SK, could be strengthened by further K2K data. Then we point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, in particular the KamLAND data, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. Finally, we perform an updated analysis of two-family active oscillations of solar and reactor neutrinos in the standard MSW case.

Symplectic symmetry of the neutrino mass for many neutrino flavors

International Nuclear Information System (INIS)

Oeztuerk, N.; Ankara Univ.

2001-01-01

The algebraic structure of the neutrino mass Hamiltonian is presented for two neutrino flavors considering both Dirac and Majorana mass terms. It is shown that the algebra is Sp(8) and also discussed how the algebraic structure generalizes for the case of more than two neutrino flavors. (orig.)

Three Dirac neutrinos

International Nuclear Information System (INIS)

Joshipura, A.S.; Rindani, S.D.

1991-01-01

The consequences of imposing an exact L e +L τ -L μ symmetry on a 6x6 matrix describing neutrino masses are discussed. The presence of right-handed neutrinos avoids the need of introducing any SU(2) Higgs triplet. Hence the conflict with the CERN LEP data on the Z width found in earlier models with L e +L τ -L μ symmetry is avoided. The L e +L τ -L μ symmetry provides an interesting realization of a recent proposal of Glashow to accommodate the 17-keV Dirac neutrino in the SU(2)xU(1) theory. All the neutrinos in this model are Dirac particles. The solar-neutrino problem can be solved in an extension of the model which generates a large (∼10 -11 μ B ) magnetic moment for the electron neutrino

Quintessential inflation on the brane and the relic gravity wave background

International Nuclear Information System (INIS)

Sami, M.; Sahni, V.

2004-01-01

Quintessential inflation describes a scenario in which both inflation and dark energy (quintessence) are described by the same scalar field. In conventional braneworld models of quintessential inflation gravitational particle-production is used to reheat the universe. This reheating mechanism is very inefficient and results in an excessive production of gravity waves which violate nucleosynthesis constraints and invalidate the model. We describe a new method of realizing quintessential inflation on the brane in which inflation is followed by 'instant preheating' (Felder, Kofman and Linde 1999). The larger reheating temperature in this model results in a smaller amplitude of relic gravity waves which is consistent with nucleosynthesis bounds. The relic gravity wave background has a 'blue' spectrum at high frequencies and is a generic byproduct of successful quintessential inflation on the brane

Measurement of neutrino flux from neutrino-electron elastic scattering

Science.gov (United States)

Park, J.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Cai, T.; Carneiro, M. F.; Christy, M. E.; Chvojka, J.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Eberly, B.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Ghosh, A.; Golan, T.; Gran, R.; Harris, D. A.; Higuera, A.; Kleykamp, J.; Kordosky, M.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman; Osta, J.; Paolone, V.; Patrick, C. E.; Perdue, G. N.; Rakotondravohitra, L.; Ramirez, M. A.; Ray, H.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Solano Salinas, C. J.; Tagg, N.; Tice, B. G.; Valencia, E.; Walton, T.; Wolcott, J.; Wospakrik, M.; Zavala, G.; Zhang, D.; Miner ν A Collaboration

2016-06-01

Muon-neutrino elastic scattering on electrons is an observable neutrino process whose cross section is precisely known. Consequently a measurement of this process in an accelerator-based νμ beam can improve the knowledge of the absolute neutrino flux impinging upon the detector; typically this knowledge is limited to ˜10 % due to uncertainties in hadron production and focusing. We have isolated a sample of 135 ±17 neutrino-electron elastic scattering candidates in the segmented scintillator detector of MINERvA, after subtracting backgrounds and correcting for efficiency. We show how this sample can be used to reduce the total uncertainty on the NuMI νμ flux from 9% to 6%. Our measurement provides a flux constraint that is useful to other experiments using the NuMI beam, and this technique is applicable to future neutrino beams operating at multi-GeV energies.

Geo-neutrino Observation

International Nuclear Information System (INIS)

Dye, S. T.; Alderman, M.; Batygov, M.; Learned, J. G.; Matsuno, S.; Mahoney, J. M.; Pakvasa, S.; Rosen, M.; Smith, S.; Varner, G.; McDonough, W. F.

2009-01-01

Observations of geo-neutrinos measure radiogenic heat production within the earth, providing information on the thermal history and dynamic processes of the mantle. Two detectors currently observe geo-neutrinos from underground locations. Other detection projects in various stages of development include a deep ocean observatory. This paper presents the current status of geo-neutrino observation and describes the scientific capabilities of the deep ocean observatory, with emphasis on geology and neutrino physics.

Neutrino masses

Energy Technology Data Exchange (ETDEWEB)

Anon.

1986-04-15

Postulated in the early days of quantum mechanics by Wolfgang Pauli to make energy-momentum conservation in nuclear beta decay come out right, the neutrino has never strayed far from physicists' attention. The Moriond Workshop on Massive Neutrinos in Particle Physics and Astrophysics held recently in the French Alps showed that more than half a century after Pauli's prediction, the neutrino stubbornly refuses to yield up all its secrets.

Neutrino mass, a status report

International Nuclear Information System (INIS)

Robertson, R.G.H.

1993-01-01

Experimental approaches to neutrino mass include kinematic mass measurements, neutrino oscillation searches at rectors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indications that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing

Effects of neutrino degeneracy and of downscatter on neutrino radiation from dense stellar cores

International Nuclear Information System (INIS)

Lichtenstadt, I.; Ron, A.; Sack, N.; Wagschal, J.J.; Bludman, S.A.

1978-01-01

A simplified model is presneted for several stages in the development of a neutronization shell in the inner core of a collapsing star. Neutrino degeneracy severely reduces neutrino emission and downscatter in energy, so that for all but the thinest shell sources, surface emission of an approximately Fermi-Dirac neutrino spectrum obtains. The Neutrino spectrum departs from exact Fermi-Dirac neutrino form only because of the outstreaming of low-energy neutrinos.Downscatter by electrons is helped by neutron scatterers present, but except for reducing the peak neutrino energy by about 30%, electrons play no dramatic part. The neutrino degeneracy inhibits downscatter so that the low-energy window in the Fermi-Dirac distribution leads to little neutrino loss.A simple equilibrium radiation picture emerges in which neutrinos are LTE thermally emitted in the neutronization shell and isotropically coherently scattered by neutrons and by nuclei on the way out of the overlying mantle. The Fermi statistics limit on neutrino flux is probably reached in practice, but is, in most cases, still insufficient for mantle blow-off

Accelerator studies of neutrino oscillations

CERN Document Server

Ereditato, A

2000-01-01

The question of whether the neutrino has a non-vanishing mass plays acrucial role in particle physics. A massive neutrino would unambiguously reveal the existence of new physics beyond the Standard Model. In addition, it could have profound implications on astrophysics and cosmology, with effects on the evolution of the Universe. Experiments aiming at direct neutrino-mass measurements based on kinematics have not been able, so far, to measure the very small neutrino mass. Indirect measurements can be performed by exploiting reactions which may only occur for massive neutrinos. Neutrino oscillation is one of those processes. The mass difference between neutrino mass-eigenstates can be inferred from a phase measurement. This feature allows for high sensitivity experiments. Neutrinos from different sources can be used to search for oscillations: solar neutrinos, neutrinos produced in the interaction of cosmic rays with the atmosphere and artificially produced neutrinos from nuclear reactors and particle accelera...

Neutrino physics in heaven

International Nuclear Information System (INIS)

Raffelt, G.

2005-01-01

After a brief overview of the usual topics that connect astrophysics and cosmology with neutrino physics I will focus on two main themes. First, what can we learn from the neutrino signal of a future galactic supernova, in particular about the neutrino mass ordering. Second, what can we learn about neutrino properties from cosmological observables, notably about the neutrino absolute mass scale from cosmological large-scale structure observables. (author)

A measurement of neutrino oscillations with muon neutrinos in the MINOS experiment

Energy Technology Data Exchange (ETDEWEB)

Coleman, Stephen James [College of William and Mary, Williamsburg, VA (United States)

2011-05-01

Experimental evidence has established that neutrino flavor states evolve over time. A neutrino of a particular flavor that travels some distance can be detected in a different neutrino flavor state. The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline experiment that is designed to study this phenomenon, called neutrino oscillations. MINOS is based at Fermilab near Chicago, IL, and consists of two detectors: the Near Detector located at Fermilab, and the Far Detector, which is located in an old iron mine in Soudan, MN. Both detectors are exposed to a beam of muon neutrinos from the NuMI beamline, and MINOS measures the fraction of muon neutrinos that disappear after traveling the 734 km between the two detectors. One can measure the atmospheric neutrino mass splitting and mixing angle by observing the energy-dependence of this muon neutrino disappearance. MINOS has made several prior measurements of these parameters. Here I describe recently-developed techniques used to enhance our sensitivity to the oscillation parameters, and I present the results obtained when they are applied to a dataset that is twice as large as has been previously analyzed. We measure the mass splitting Δm₂₃² = (2.32_-0.08^+0.12) x 10^-3 eV²/c⁴ and the mixing angle sin²(2θ₃₂) > 0.90 at 90% C.L. These results comprise the world's best measurement of the atmospheric neutrino mass splitting. Alternative disappearance models are also tested. The neutrino decay hypothesis is disfavored at 7.2σ and the neutrino quantum decoherence hypothesis is disfavored at 9.0σ.

Flavor composition of the IceCube neutrinos: A quest for sterile neutrinos?

International Nuclear Information System (INIS)

Biondi, R.

2016-01-01

The identification of flavor content in the cosmic high-energy neutrinos recently observed by the IceCube collaboration could spread the light on the origin of these neutrinos. We study the expected fraction of muon tracks for different cases of the neutrino flavor composition at the sources taking into account uncertainties in the neutrino mixing angles and CP-phase. We show that in the frame of the three known neutrinos it is hard to explain the ν_μ fraction observed at IceCube. However if the cosmic component is produced in some hidden sector, in the form of sterile neutrinos which then oscillate into ordinary ones, a better agreement can be obtained. Especially, in a scenario when heavy dark matter with mass of few PeV decay into sterile neutrinos which then oscillate in ordinary neutrinos due to tiny mixing with the latter, it is possible to explain the low fraction of muon tracks in the events observed by IceCube in the energy region from 60TeV to 2PeV

Measurement of Atmospheric Neutrino Oscillations with Very Large Volume Neutrino Telescopes

Directory of Open Access Journals (Sweden)

J. P. Yáñez

2015-01-01

Full Text Available Neutrino oscillations have been probed during the last few decades using multiple neutrino sources and experimental set-ups. In the recent years, very large volume neutrino telescopes have started contributing to the field. First ANTARES and then IceCube have relied on large and sparsely instrumented volumes to observe atmospheric neutrinos for combinations of baselines and energies inaccessible to other experiments. Using this advantage, the latest result from IceCube starts approaching the precision of other established technologies and is paving the way for future detectors, such as ORCA and PINGU. These new projects seek to provide better measurements of neutrino oscillation parameters and eventually determine the neutrino mass ordering. The results from running experiments and the potential from proposed projects are discussed in this review, emphasizing the experimental challenges involved in the measurements.

Galactic neutrino communication

Energy Technology Data Exchange (ETDEWEB)

Learned, John G. [Department of Physics and Astronomy, University of Hawaii, 2505 Correa Road, Honolulu, HI 96822 (United States)], E-mail: jgl@phys.hawaii.edu; Pakvasa, Sandip [Department of Physics and Astronomy, University of Hawaii, 2505 Correa Road, Honolulu, HI 96822 (United States)], E-mail: pakvasa@phys.hawaii.edu; Zee, A. [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States)], E-mail: zee@kitp.ucsb.edu

2009-01-12

We examine the possibility to employ neutrinos to communicate within the galaxy. We discuss various issues associated with transmission and reception, and suggest that the resonant neutrino energy near 6.3 PeV may be most appropriate. In one scheme we propose to make Z deg. particles in an overtaking e{sup +}-e{sup -} collider such that the resulting decay neutrinos are near the W{sup -} resonance on electrons in the laboratory. Information is encoded via time structure of the beam. In another scheme we propose to use a 30 PeV pion accelerator to create neutrino or anti-neutrino beams. The latter encodes information via the beam CP state as well as timing. Moreover the latter beam requires far less power, and can be accomplished with presently foreseeable technology. Such signals from an advanced civilization, should they exist, will be eminently detectable in existing neutrino detectors.

The ideal neutrino beams

Science.gov (United States)

Lindroos, Mats

2009-06-01

The advance in neutrino oscillation physics is driven by the availability of well characterized and high flux neutrino beams. The three present options for the next generation neutrino oscillation facility are super beams, neutrino factories and beta-beams. A super-beam is a very high intensity classical neutrino beam generated by protons impinging on a target where the neutrinos are generated by the secondary particles decaying in a tunnel down streams of the target. In a neutrino factory the neutrinos are generated from muons decaying in a storage ring with long straight sections pointing towards the detectors. In a beta-beam the neutrinos are also originating from decay in a storage ring but the decaying particles are radioactive ions rather than muons. I will in this presentation review the three options and discuss the pros and cons of each. The present joint design effort for a future high intensity neutrino oscillation in Europe within a common EU supported design study, EURONU, will also be presented. The design study will explore the physics reach, the detectors, the feasibility, the safety issues and the cost for each of the options so that the the community can take a decision on what to build when the facilities presently under exploitation and construction have to be replaced.

Sudbury neutrino observatory

International Nuclear Information System (INIS)

Ewan, G.T.; Evans, H.C.; Lee, H.W.

1986-10-01

This report is a supplement to a report (SNO-85-3 (Sudbury Neutrino Observatory)) which contained the results of a feasibility study on the construction of a deep underground neutrino observatory based on a 1000 ton heavy water Cerenkov detector. Neutrinos carry detailed information in their spectra on the reactions taking place deep in the interstellar interior and also provide information on supernova explosions. In addition to their role as astrophysical probes, a knowledge of the properties of neutrinos is crucial to theories of grand unification. The Sudbury Neutrino Observatory is unique in its high sensitivity to electron neutrinos and its ability to detect all other types of neutrinos of energy greater than 2.2 MeV. The results of the July 1985 study indicated that the project is technically feasible in that the proposed detector can measure the direction and energy of electron neutrinos above 7 MeV and the scientific programs will make significant contributions to physics and astrophysics. This present report contains new information obtained since the 1985 feasibility study. The enhanced conversion of neutrinos in the sun and the new physics that could be learned using the heavy water detector are discussed in the physics section. The other sections will discuss progress in the areas of practical importance in achieving the physics objectives such as new techniques to measure, monitor and remove low levels of radioactivity in detector components, ideas on calibration of the detector and so forth. The section entitled Administration contains a membership list of the working groups within the SNO collaboration

Proto-ribosome: a theoretical approach based on RNA relics

OpenAIRE

Demongeot, Jacques

2017-01-01

We describe in this paper, based on already published articles, a contribution to the theory postulating the existence of a proto-ribosome, which could have appeared early at the origin of life and we discuss the interest of this notion in an evolutionary perspective, taking into account the existence of possible RNA relics of this proto-ribosome.

Evidence for neutrino oscillations in the Sudbury Neutrino Observatory

Energy Technology Data Exchange (ETDEWEB)

Marino, Alysia Diane [Univ. of California, Berkeley, CA (United States)

2004-01-01

The Sudbury Neutrino Observatory (SNO) is a large-volume heavy water Cerenkov detector designed to resolve the solar neutrino problem. SNO observes charged-current interactions with electron neutrinos, neutral-current interactions with all active neutrinos, and elastic-scattering interactions primarily with electron neutrinos with some sensitivity to other flavors. This dissertation presents an analysis of the solar neutrino flux observed in SNO in the second phase of operation, while ~2 tonnes of salt (NaCl) were dissolved in the heavy water. The dataset here represents 391 live days of data. Only the events above a visible energy threshold of 5.5 MeV and inside a fiducial volume within 550 cm of the center of the detector are studied. The neutrino flux observed via the charged-current interaction is [1.71 ± 0.065(stat.)±$0.065\\atop{0.068}$(sys.)±0.02(theor.)] x 10⁶cm^-2s^-1, via the elastic-scattering interaction is [2.21±0.22(stat.)±$0.12\\atop{0.11}$(sys.)±0.01(theor.)] x 10⁶cm^-2s^-1, and via the neutral-current interaction is [5.05±0.23(stat.)±$0.31\\atop{0.37}$(sys.)±0.06(theor.)] x 10⁶cm^-2s^-1. The electron-only flux seen via the charged-current interaction is more than 7σ below the total active flux seen via the neutral-current interaction, providing strong evidence that neutrinos are undergoing flavor transformation as they travel from the core of the Sun to the Earth. The most likely origin of the flavor transformation is matter-induced flavor oscillation.

Neutrino masses

International Nuclear Information System (INIS)

Anon.

1986-01-01

Postulated in the early days of quantum mechanics by Wolfgang Pauli to make energy-momentum conservation in nuclear beta decay come out right, the neutrino has never strayed far from physicists' attention. The Moriond Workshop on Massive Neutrinos in Particle Physics and Astrophysics held recently in the French Alps showed that more than half a century after Pauli's prediction, the neutrino stubbornly refuses to yield up all its secrets

Working Group Report: Neutrinos

Energy Technology Data Exchange (ETDEWEB)

de Gouvea, A.; Pitts, K.; Scholberg, K.; Zeller, G. P. [et al.

2013-10-16

This document represents the response of the Intensity Frontier Neutrino Working Group to the Snowmass charge. We summarize the current status of neutrino physics and identify many exciting future opportunities for studying the properties of neutrinos and for addressing important physics and astrophysics questions with neutrinos.

Experimental Neutrino Physics

Energy Technology Data Exchange (ETDEWEB)

Wilkes, Richard Jeffrey [Univ. of Washington, Seattle, WA (United States)

2017-11-15

The University of Washington (UW) HEP neutrino group performed experimental research on the physics of neutrinos, using the capabilities offered by the T2K Experiment and the Super-Kamiokande Neutrino Observatory. The UW group included senior investigator R. J. Wilkes, two PhD students, four MS degree students, and a research engineer, all of whom are members of the international scientific collaborations for T2K and Super-Kamiokande. During the period of support, within T2K we pursued new precision studies sensitive to new physics, going beyond the limits of current measurements of the fundamental neutrino oscillation parameters (mass differences and mixing angles). We began efforts to measure (or significantly determine the absence of) 1 the CP-violating phase parameter δCP and determine the neutrino mass hierarchy. Using the Super-Kamiokande (SK) detector we pursued newly increased precision in measurement of neutrino oscillation parameters with atmospheric neutrinos, and extended the current reach in searches for proton decay, in addition to running the most sensitive supernova watch instrument [Scholberg 2012], performing other astrophysical neutrino studies, and analyzing beam-induced events from T2K. Overall, the research addressed central questions in the field of particle physics. It included the training of graduate students (both PhD and professional MS degree students), and postdoctoral researchers. Undergraduate students also participated as laboratory assistants.

Monochromatic neutrinos from massive fourth generation neutrino annihilation in the Sun and Earth

International Nuclear Information System (INIS)

Belotskij, K.M.; Khlopov, M.Yu.; Shibaev, K.I.

2001-01-01

Accumulation inside the Earth and Sun of heavy (with the mass of 50 GeV) primordial neutrinos and antineutrinos of the fourth generation and their successive annihilation is considered. The minimal estimations of annihilational fluxes of monochromatic e, μ, τ neutrinos (neutrinos and antineutrinos) with the energy of 50 GeV are 4.1·10 -6 cm -2 ·s -1 from the Earth core and 1.1·10 -7 cm -2 ·s -1 from the Sun core. That makes the analysis of underground neutrino observatory data the additional source of information on the existence of massive stable 4th generation neutrino. It is shown that due to the kinetic equilibrium between the influx of the neutrinos and their annihilation the existence of new U(1)-gauge interaction of the 4th generation neutrino does not virtually influence the estimations of annihilational e-, μ-, τ-neutrino fluxes

Neutrino masses and mixings: Big Bang and Supernova nucleosynthesis and neutrino dark matter

International Nuclear Information System (INIS)

Fuller, George M.

1999-01-01

The existence of small mixings between light active and sterile neutrino species could have implications for Big Bang and Supernova Heavy Element Nucleosynthesis. As well, such mixing would force us to abandon cherished constraints on light neutrino Dark Matter. Two proposed 4-neutrino mass and mixing schemes, for example, can both accomodate existing experimental results and lead to elegant solutions to the neutron-deficit problem for r-Process nucleosynthesis from neutrino-heated supernova ejecta. Each of these solutions is based on matter-enhanced (MSW) active-sterile neutrino transformation. In plausible extensions of these schemes to the early universe, Shi and Fuller have shown that relatively light mass (∼200 eV to ∼10 keV) sterile neutrinos produced via active-sterile MSW conversion can have a ''cold'' energy spectrum. Neutrinos produced in this way circumvent the principal problem of light neutrino dark matter and would be, essentially, Cold Dark Matter

CrossRef Neutrino factories

CERN Document Server

Wildner, Elena

2016-01-01

Neutrinos are produced by many processes in our universe. These elusive particles reach the earth having a certain energy permitting them to react with nuclei in detectors that are specifically designed to probe their properties. However, to get higher intensities and higher energy neutrinos for better statistics and better physics reach, the use of accelerators is necessary to advance in the field of neutrino research. To produce neutrinos with an accelerator, one needs to send a high power beam onto a target to get particles or isotopes that produce neutrinos with the required properties, by decay. The parent particles have to be collected and prepared for injection into an accelerating structure. Accelerator-based experiments can tune the energy of the produced neutrinos by boosting and controlling the energy of the parent particle. The produced neutrinos will travel the distance between the source and the detector, generally through earth; the distance the neutrino travels through earth, the energy of the...

Sudbury neutrino observatory proposal

International Nuclear Information System (INIS)

Ewan, G.T.; Evans, H.C.; Lee, H.W.

1987-10-01

This report is a proposal by the Sudbury Neutrino Observatory (SNO) collaboration to develop a world class laboratory for neutrino astrophysics. This observatory would contain a large volume heavy water detector which would have the potential to measure both the electron-neutrino flux from the sun and the total solar neutrino flux independent of neutrino type. It will therefore be possible to test models of solar energy generation and, independently, to search for neutrino oscillations with a sensitivity many orders of magnitude greater than that of terrestrial experiments. It will also be possible to search for spectral distortion produced by neutrino oscillations in the dense matter of the sun. Finally the proposed detector would be sensitive to neutrinos from a stellar collapse and would detect neutrinos of all types thus providing detailed information on the masses of muon- and tau-neutrinos. The neutrino detector would contain 1000 tons of D20 and would be located more than 2000 m below ground in the Creighton mine near Sudbury. The operation and performance of the proposed detector are described and the laboratory design is presented. Construction schedules and responsibilities and the planned program of technical studies by the SNO collaboration are outlined. Finally, the total capital cost is estimated to be $35M Canadian and the annual operating cost, after construction, would be $1.8 M Canadian, including the insurance costs of the heavy water

Production of heavy sterile neutrinos from vector boson decay at electroweak temperatures

Science.gov (United States)

Lello, Louis; Boyanovsky, Daniel; Pisarski, Robert D.

2017-02-01

In the standard model extended with a seesaw mass matrix, we study the production of sterile neutrinos from the decay of vector bosons at temperatures near the masses of the electroweak bosons. We derive a general quantum kinetic equation for the production of sterile neutrinos and their effective mixing angles, which is applicable over a wide range of temperature, to all orders in interactions of the standard model and to leading order in a small mixing angle for the neutrinos. We emphasize the relation between the production rate and Landau damping at one-loop order and show that production rates and effective mixing angles depend sensitively upon the neutrino's helicity. Sterile neutrinos with positive helicity interact more weakly with the medium than those with negative helicity, and their effective mixing angle is not modified significantly. Negative helicity states couple more strongly to the vector bosons, but their mixing angle is strongly suppressed by the medium. Consequently, if the mass of the sterile neutrino is ≲8.35 MeV , there are fewer states with negative helicity produced than those with positive helicity. There is an Mikheyev-Smirnov-Wolfenstein-type resonance in the absence of lepton asymmetry, but due to screening by the damping rate, the production rate is not enhanced. Sterile neutrinos with negative helicity freeze out at Tf-≃5 GeV , whereas positive helicity neutrinos freeze out at Tf+≃8 GeV , with both distributions far from thermal. As the temperature decreases, due to competition between a decreasing production rate and an increasing mixing angle, the distribution function for states with negative helicity is broader in momentum and hotter than that for those with positive helicity. Sterile neutrinos produced via vector boson decay do not satisfy the abundance, lifetime, and cosmological constraints to be the sole dark matter component in the Universe. Massive sterile neutrinos produced via vector boson decay might solve the 7Li

Mirror model for sterile neutrinos

International Nuclear Information System (INIS)

Berezinsky, Veniamin; Narayan, Mohan; Vissani, Francesco

2003-01-01

Sterile neutrinos are studied as subdominant contribution to solar neutrino physics. The mirror-matter neutrinos are considered as sterile neutrinos. We use the symmetric mirror model with gravitational communication between mirror and visible sectors. This communication term provides mixing between visible and mirror neutrinos with the basic scale μ=v EW 2 /M Pl =2.5x10 -6 eV, where v EW =174 GeV is the vacuum expectation value of the standard electroweak group and M Pl is the Planckian mass. It is demonstrated that each mass eigenstate of active neutrinos splits into two states separated by small Δm 2 . Unsuppressed oscillations between active and sterile neutrinos (ν a ↔ν s ) occur only in transitions between each of these close pairs ('windows'). These oscillations are characterized by very small Δm 2 and can suppress the flux and distort spectrum of pp-neutrinos in detectable way. The other observable effect is anomalous seasonal variation of neutrino flux, which appears in LMA solution. The considered subdominant neutrino oscillations ν a ↔ν s can reveal itself as big effects in observations of supernova neutrinos and high-energy (HE) neutrinos. In the case of HE neutrinos they can provide a very large diffuse flux of active neutrinos unconstrained by the e-m cascade upper limit

Monochromatic neutrino beams

International Nuclear Information System (INIS)

Bernabeu, Jose; Burguet-Castell, Jordi; Espinoza, Catalina; Lindroos, Mats

2005-01-01

In the last few years spectacular results have been achieved with the demonstration of non vanishing neutrino masses and flavour mixing. The ultimate goal is the understanding of the origin of these properties from new physics. In this road, the last unknown mixing [U e3 ] must be determined. If it is proved to be non-zero, the possibility is open for Charge Conjugation-Parity (CP) violation in the lepton sector. This will require precision experiments with a very intense neutrino source. Here a novel method to create a monochromatic neutrino beam, an old dream for neutrino physics, is proposed based on the recent discovery of nuclei that decay fast through electron capture. Such nuclei will generate a monochromatic directional neutrino beam when decaying at high energy in a storage ring with long straight sections. We also show that the capacity of such a facility to discover new physics is impressive, so that fine tuning of the boosted neutrino energy allows precision measurements of the oscillation parameters even for a [U e3 ] mixing as small as 1 degree. We can thus open a window to the discovery of CP violation in neutrino oscillations

Measurement of the Charged-Current Quasi-Elastic Cross-Section for Electron Neutrinos on a Hydrocarbon Target

Energy Technology Data Exchange (ETDEWEB)

Wolcott, Jeremy [Univ. of Rochester, NY (United States)

2016-01-01

Appearance-type neutrino oscillation experiments, which observe the transition from muon neutrinos to electron neutrinos, promise to help answer some of the fundamental questions surrounding physics in the post-Standard-Model era. Because they wish to observe the interactions of electron neutrinos in their detectors, and because the power of current results is typically limited by their systematic uncertainties, these experiments require precise estimates of the cross-section for electron neutrino interactions. Of particular interest is the charged-current quasi-elastic (CCQE) process, which gures signi cantly in the composition of the reactions observed at the far detector. However, no experimental measurements of this crosssection currently exist for electron neutrinos; instead, current experiments typically work from the abundance of muon neutrino CCQE cross-section data and apply corrections from theoretical arguments to obtain a prediction for electron neutrinos. Veri cation of these predictions is challenging due to the di culty of constructing an electron neutrino beam, but the advent of modern high-intensity muon neutrino beams|together with the percent-level electron neutrino impurity inherent in these beams| nally presents the opportunity to make such a measurement. We report herein the rst-ever measurement of a cross-section for an exclusive state in electron neutrino scattering, which was made using the MINER A detector in the NuMI neutrino beam at Fermilab. We present the electron neutrino CCQE di erential cross-sections, which are averaged over neutrinos of energies 1-10 GeV (with mean energy of about 3 GeV), in terms of various kinematic variables: nal-state electron angle, nal-state electron energy, and the square of the fourmomentum transferred to the nucleus by the neutrino , Q². We also provide a total cross-section vs. neutrino energy. While our measurement of this process is found to be in agreement with the predictions of the GENIE

Experimental Neutrino Physics: Final Report

Energy Technology Data Exchange (ETDEWEB)

Lane, Charles E.; Maricic, Jelena

2012-09-05

Experimental studies of neutrino properties, with particular emphasis on neutrino oscillation, mass and mixing parameters. This research was pursued by means of underground detectors for reactor anti-neutrinos, measuring the flux and energy spectra of the neutrinos. More recent investigations have been aimed and developing detector technologies for a long-baseline neutrino experiment (LBNE) using a neutrino beam from Fermilab.

Neutrino physics present and future

CERN Multimedia

CERN. Geneva

2006-01-01

Our understanding of neutrinos has been revolutionized by the discovery that they have nonzero masses and very large mixing. We will explain the phenomenology of massive neutrinos, including neutrino oscillation in vacuum and in matter, and the physics of neutrinos that are their own antiparticles. We will review the evidence for neutrino masses and mixing, and summarize what has been learned about the neutrinos so far. Identifying the very interesting open questions raised by the discovery of neutrino mass, we will discuss how these questions may be answered through future experiments. Finally, we will consider the possibility that CP violation by neutrinos is the key to understanding the matter-antimatter asymmetry of the universe, and discuss the see-saw theory of why neutrino masses are so tiny.

Two lectures on neutrinos

International Nuclear Information System (INIS)

Ramond, P.

1992-01-01

These notes are based on two lectures delivered at the School. A general description of neutrinos is presented, first in purely kinematic terms, then in the context of the Standard Model, focusing on the role of the global lepton numbers. Standard Model extensions with massive neutrinos are cataloged. Several popular mass matrices for neutrinos, and their consequences are presented. They proceed to give an extended discussion of neutrino oscillations in matter, and apply the results to the solar neutrinos

Neutrino mass matrix

International Nuclear Information System (INIS)

Strobel, E.L.

1985-01-01

Given the many conflicting experimental results, examination is made of the neutrino mass matrix in order to determine possible masses and mixings. It is assumed that the Dirac mass matrix for the electron, muon, and tau neutrinos is similar in form to those of the quarks and charged leptons, and that the smallness of the observed neutrino masses results from the Gell-Mann-Ramond-Slansky mechanism. Analysis of masses and mixings for the neutrinos is performed using general structures for the Majorana mass matrix. It is shown that if certain tentative experimental results concerning the neutrino masses and mixing angles are confirmed, significant limitations may be placed on the Majorana mass matrix. The most satisfactory simple assumption concerning the Majorana mass matrix is that it is approximately proportional to the Dirac mass matrix. A very recent experimental neutrino mass result and its implications are discussed. Some general properties of matrices with structure similar to the Dirac mass matrices are discussed

NEUTRINO MASS

OpenAIRE

Kayser, Boris

1988-01-01

This is a review article about the most recent developments on the field of neutrino mass. The first part of the review introduces the idea of neutrino masses and mixing angles, summarizes the most recent experimental data then discusses the experimental prospects and challenges in this area. The second part of the review discusses the implications of these results for particle physics and cosmology, including the origin of neutrino mass, the see-saw mechanism and sequential dominance, and la...

The Deep Underground Neutrino Experiment: The precision era of neutrino physics

Energy Technology Data Exchange (ETDEWEB)

Kemp, E. [Gleb Wataghin Institute of Physics, Universidade de Campinas - UNICAMP, Campinas Brazil

2017-12-01

The last decade was remarkable for neutrino physics. In particular, the phenomenon of neutrino flavor oscillations has been firmly established by a series of independent measurements. All parameters of the neutrino mixing are now known, and we have the elements to plan a judicious exploration of new scenarios that are opened by these recent advances. With precise measurements, we can test the three-neutrino paradigm, neutrino mass hierarchy, and charge conjugation parity (CP) asymmetry in the lepton sector. The future long-baseline experiments are considered to be a fundamental tool to deepen our knowledge of electroweak interactions. The Deep Underground Neutrino Experiment (DUNE) will detect a broadband neutrino beam from Fermilab in an underground massive liquid argon time-projection chamber at an L/E of about 103 km GeV-1 to reach good sensitivity for CP-phase measurements and the determination of the mass hierarchy. The dimensions and the depth of the far detector also create an excellent opportunity to look for rare signals like proton decay to study violation of the baryonic number, as well as supernova neutrino bursts, broadening the scope of the experiment to astrophysics and associated impacts in cosmology. In this paper, we discuss the physics motivations and the main experimental features of the DUNE project required to reach its scientific goals.

Prospects for detecting supersymmetric dark matter at Post-LEP benchmark points

International Nuclear Information System (INIS)

Ellis, J.; Matchev, K.T.; Feng, J.L.; Ferstl, A.; Olive, K.A.

2002-01-01

A new set of supersymmetric benchmark scenarios has recently been proposed in the context of the constrained MSSM (CMSSM) with universal soft supersymmetry-breaking masses, taking into account the constraints from LEP, b→sγ and g μ -2. These points have previously been used to discuss the physics reaches of different accelerators. In this paper, we discuss the prospects for discovering supersymmetric dark matter in these scenarios. We consider direct detection through spin-independent and spin-dependent nuclear scattering, as well as indirect detection through relic annihilations to neutrinos, photons, and positrons. We find that several of the benchmark scenarios offer good prospects for direct detection via spin-independent nuclear scattering and indirect detection via muons produced by neutrinos from relic annihilations inside the Sun, and some models offer good prospects for detecting photons from relic annihilations in the galactic centre. (orig.)

Towards neutrino astronomy

International Nuclear Information System (INIS)

Lagage, P.O.; Spiro, M.

1985-01-01

Neutrino sources are numerous and varied; the sun, a supernova explosion, the cosmic radiation interaction with interstellar medium are neutrino or antineutrino sources. The aim of this article is to overview the international projects of neutrino detection while giving the preference to the experimental side of the detection [fr

Can neutrino-electron scattering tell us whether neutrinos are Dirac or Majorana particles?

International Nuclear Information System (INIS)

Kayser, B.

1988-04-01

There has recently been interest in the possibility that neutrino-electron scattering experiments could determine whether neutrinos are Dirac or Majorana particles by providing information on their electromagnetic structure. We try to explain why studies of neutrino electromagnetic structure actually cannot distinguish between Dirac and Majorana neutrinos. 9 refs

Accelerator and Technical Sector Seminar: Future neutrino facilities: the neutrino factory

CERN Multimedia

2012-01-01

Thursday 19.January 2012 at 14:15  -  IT Auditorium (bldg. 31 3-004) Future neutrino facilities: the neutrino factory by Gersende Prior / University of Geneva and CERN EN/MEF The neutrino factory is one of the proposed designs for a future intense neutrino beam facility. In its current layout, a high-power proton beam impinges on an Hg jet target producing pions, decaying in turn into muons. In order to reduce the particle beam emittance, the muon transverse momentum is reduced through ionization cooling by a technically demanding set-up made of closely-packed RF cavities alternating with absorbers. In this talk I will present the motivation for building an intense neutrino beam and some of the proposed neutrino facilities' design. I will discuss the challenges inherent to the cooling of muons, possible optimization of the current baseline and the on-going R&D. ________________ ATS Seminars Organisers: H. Burkhardt (BE), S. Sgobba (EN), G. deRijk (TE)

Neutrino mixing and lepton CP-phase in neutrino oscillations

International Nuclear Information System (INIS)

Ryzhikh, D.A.; Ter-Martirosyan, K.A.

2001-01-01

One studied oscillations of the Dirac neutrinos belonging to three generations in vacuum with regard to the effect of the lepton CP-breaking phase on them in the matrix of lepton mixing (analogue of the quark CP-phase). In the general form one obtained formulae for probabilities of transition of neutrino of one kind to another at oscillations depending on three angles of mixing and on CP-phase. It was pointed that when measuring oscillation average probabilities of transition of neutrino of one kind to another one might in principle, restore the value of lepton CP-phase. Manifestation of CP-phase in the form of deviation of the values of probabilities of direct neutrino transition from reverse one is the effect practically escaping observation [ru

Solar neutrino

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, D [Tokyo Univ. (Japan). Coll. of General Education

1975-01-01

The measurement of solar neutrino was performed by using the reaction /sup 37/cl+..nu..sub(e)..-->../sup 37/Ar+e/sup -/ by Davis et al. The argon gas produced through the above mentioned reaction in a tank containing 610 ton of C/sub 2/Cl/sub 4/ was collected and measured. The rate of production of /sup 37/Ar was 0.13+-0.20/day, and the net production rate by the solar neutrino was 0.06+-0.20/day, being corrected for background. This value corresponds to 0.5+-1.0 SNU. Theoretical calculation with the model of spherically symmetric solar development gave an expected value of 5.6 SNU, which is in contradiction with the experimental value. Reason of this discrepancy was considered. The possibility of decay of neutrino to the other particles with weak interaction is very slight. Various models of the sun were investigated, but the results were still inconsistent with the experiment. The mixing of matters in the sun may cause the reduction of neutrino. If He gas comes to the center of the sun by mixing, the reaction, /sup 3/He+/sup 3/He, progresses excessively at the center, and it produces the expansion of the core of the sun. Then, the temperature drops and the neutrino is reduced. Various models which can explain the neutrino of less than ISNU have been presented. However, other theory says that the reduction of neutrino is not expected even if the mixing is considered. A problem concerning the mixing is whether the thermal instability which causes the mixing exists. (Kato, T.).

Neutrino mass

International Nuclear Information System (INIS)

Robertson, R.G.H.

1992-01-01

Despite intensive experimental work since the neutrino's existence was proposed by Pauli 60 years ago, and its first observation by Reines and Cowan almost 40 years ago, the neutrino's fundamental properties remain elusive. Among those properties are the masses of the three known flavors, properties under charge conjugation, parity and time-reversal, and static and dynamic electromagnetic moments. Mass is perhaps the most fundamental, as it constrains the other properties. The present status of the search for neutrino mass is briefly reviewed

Reactor Neutrino Detection for Non Proliferation with the NUCIFER Experiment

Energy Technology Data Exchange (ETDEWEB)

Bouvet, L. [CEA, Centre de Saclay, IRFU, Gif-sur-Yvette, (France); Bouvier, S.; Bui, V. M. [Laboratoire Subatech, Ecole des Mines, Nantes Cedex 3 (France); others, and

2012-06-15

Neutrinos are the most abundant matter particles in the Universe. Thoroughly investigated in basic science, the neutrino field is now delivering first applications to the monitoring of nuclear reactors. The neutrinos are emitted in the decay chain of the fission products; therefore measuring their flux provides real-time information, directly related to the fission process occurring in the reactor core. Because of the very weak interaction of neutrinos with matter a neutrino detector can stand outside the core containment vessel and provide a non-intrusive and inherently tamper resistant measurement. After a brief review of the existing data and worldwide projects, we present the NUCIFER experiment. The active part of the detector is a tank filled up with one ton of Gadolinium-doped liquid scintillator. Sixteen photomultiplier tubes, isolated from the liquid by an acrylic buffer, read out the light produced by the interaction of a neutrino with the protons of the liquid. The tank is surrounded by plastic scintillator plates to veto the cosmic rays. Then polyethylene and lead shielding suppress the background coming from external neutrons and gamma rays respectively. The NUCIFER detector has been designed for an optimal compromise between the detection performances and the specifications of operation in a safeguards regime. Its global footprint is 2.8 m x 2.8 m and it can monitor remotely the nuclear power plant thermal power and Plutonium content with very little maintenance on years scale. The experiment is currently installed near the OSIRIS research reactor (70 MWth) at CEA, in Saclay, France. First data are expected by May 2012. This work is done in contact with the IAEA/SGTN division that is currently investigating the potentiality of neutrinos as a novel safeguards tool. A dedicated working group has been created in 2010 to coordinate the simulation effort of various reactor types as well as the development of dedicated detectors and define and eventually

Neutrino Oscillation Physics

International Nuclear Information System (INIS)

Kayser, Boris

2014-01-01

To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures

Neutrino Oscillation Physics

Energy Technology Data Exchange (ETDEWEB)

Kayser, Boris [Fermilab (United States)

2014-07-01

To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures.

Solar neutrino experiments

International Nuclear Information System (INIS)

Hampel, W.

1996-01-01

The present status of experimental solar neutrino research is reviewed. Updated results from the Homestake, Kamiokande, GALLEX and SAGE detectors all show a deficit when compared to recent standard solar model calculations. Two of these detectors, GALLEX and SAGE, have recently been checked with artificial 51 Cr neutrino sources. It is shown that astrophysical scenarios to solve the solar neutrino problems are not favoured by the data. There is hope that the results of forthcoming solar neutrino experiments can provide the answers to the open questions. (author) 6 figs., 3 tabs., 36 refs

Solar neutrino experiments

Energy Technology Data Exchange (ETDEWEB)

Hampel, W [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

1996-11-01

The present status of experimental solar neutrino research is reviewed. Updated results from the Homestake, Kamiokande, GALLEX and SAGE detectors all show a deficit when compared to recent standard solar model calculations. Two of these detectors, GALLEX and SAGE, have recently been checked with artificial {sup 51}Cr neutrino sources. It is shown that astrophysical scenarios to solve the solar neutrino problems are not favoured by the data. There is hope that the results of forthcoming solar neutrino experiments can provide the answers to the open questions. (author) 6 figs., 3 tabs., 36 refs.

LSND neutrino oscillation results

International Nuclear Information System (INIS)

Louis, W.C.

1996-01-01

In the past several years, a number of experiments have searched for neutrino oscillations, where a neutrino of one type (say bar ν μ ) spontaneously transforms into a neutrino of another type (say bar ν e ). For this phenomenon to occur, neutrinos must be massive and the apparent conservation law of lepton families must be violated. In 1995 the LSND experiment published data showing candidate events that are consistent with bar ν μ oscillations. Additional data are reported here which provide stronger evidence for neutrino oscillations

Updated determination of the solar neutrino fluxes from solar neutrino data

Energy Technology Data Exchange (ETDEWEB)

Bergström, Johannes [Departament d’Estructura i Constituents de la Matèria and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Gonzalez-Garcia, M. C. [Departament d’Estructura i Constituents de la Matèria and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA) (Spain); C.N. Yang Institute for Theoretical Physics,State University of New York at Stony Brook, Stony Brook, NY 11794-3840 (United States); Maltoni, Michele [Instituto de Física Teórica UAM/CSIC,Calle de Nicolás Cabrera 13-15, Universidad Autónoma de Madrid,Cantoblanco, E-28049 Madrid (Spain); Peña-Garay, Carlos [Instituto de Física Corpuscular (IFIC), CSIC and Universitat de Valencia,Calle Catedrático José Beltrán, 2, E-46090 Paterna, Valencia (Spain); Serenelli, Aldo M. [Institut de Ciencies de l’Espai (ICE-CSIC/IEEC),Campus UAB, Carrer de Can Magrans s/n, 08193 Cerdanyola del Valls (Spain); Song, Ningqiang [C.N. Yang Institute for Theoretical Physics,State University of New York at Stony Brook, Stony Brook, NY 11794-3840 (United States)

2016-03-18

We present an update of the determination of the solar neutrino fluxes from a global analysis of the solar and terrestrial neutrino data in the framework of three-neutrino mixing. Using a Bayesian analysis we reconstruct the posterior probability distribution function for the eight normalization parameters of the solar neutrino fluxes plus the relevant masses and mixing, with and without imposing the luminosity constraint. We then use these results to compare the description provided by different Standard Solar Models. Our results show that, at present, both models with low and high metallicity can describe the data with equivalent statistical agreement. We also argue that even with the present experimental precision the solar neutrino data have the potential to improve the accuracy of the solar model predictions.

Neutrinos at CERN

International Nuclear Information System (INIS)

Anon.

1993-01-01

CERN's long and distinguished neutrino tradition began in 1958 at the then new 500 MeV synchrocyclotron (SC) with the first observation of the decay of a charged pion into an electron and a neutrino. At that time, the first ideas on the special (vector/axial vector) structure of the weak interactions had been put forward by Feynman and Gell-Mann and by Marshak and Sudarshan, but the continual non-observation of that charged pion decay was holding up progress. This decay is only one part in ten thousand, and is masked by the dominant muon-neutrino channel. A special telescope was built to pick up the high energy electrons from the pion decay. In 1962 came another SC neutrino success, with the first measurement of the decay of a charged pion into a neutral one, with emission of an electron and a neutrino. Meanwhile the main thrust of CERN's neutrino effort was taking shape at the PS. By the close of 1960, CERN had decided to attack neutrino physics using several detectors - a 1m heavy liquid bubble chamber from Andre Lagarrigue's team in Paris, a CERN 1 m heavy liquid bubble chamber, and a hybrid chamber/counter from a group led by Helmut Faissner

Active-sterile neutrino conversion: consequences for the r-process and supernova neutrino detection

Science.gov (United States)

Fetter, J.; McLaughlin, G. C.; Balantekin, A. B.; Fuller, G. M.

2003-02-01

We examine active-sterile neutrino conversion in the late time post-core-bounce supernova environment. By including the effect of feedback on the Mikheyev-Smirnov-Wolfenstein (MSW) conversion potential, we obtain a large range of neutrino mixing parameters which produce a favorable environment for the r-process. We look at the signature of this effect in the current generation of neutrino detectors now coming on line. We also investigate the impact of the neutrino-neutrino forward-scattering-induced potential on the MSW conversion.

Resolving neutrino mass hierarchy from supernova (anti)neutrino-nucleus reactions

Science.gov (United States)

Vale, Deni; Paar, Nils

2015-10-01

Recently a hybrid method has been introduced to determine neutrino mass hierarchy by simultaneous measurements of detector responses induced by antineutrino and neutrino fluxes from accretion and cooling phase of type II supernova. The (anti)neutrino-nucleus cross sections for 12C, 16O, 56Fe and 208Pb are calculated in the framework of relativistic nuclear energy density functional and weak interaction Hamiltonian, while the cross sections for inelastic scattering on free protons in mineral oil and water, p (v¯e,e+)n are obtained using heavy-baryon chiral perturbation theory. The simulations of (anti)neutrino fluxes emitted from a proto-neutron star in a core-collapse supernova include collective and Mikheyev-Smirnov-Wolfenstein effects inside star. It is shown that simultaneous use of ve/v¯e detectors with different target material allow to determine the neutrino mass hierarchy from the ratios of ve/v¯e induced particle emissions. The hybrid method favors detectors with heavier target nuclei (208Pb) for the neutrino sector, while for antineutrinos the use of free protons in mineral oil and water is more appropriate.

Visible neutrino decay at DUNE

Energy Technology Data Exchange (ETDEWEB)

Coloma, Pilar [Fermilab; Peres, Orlando G. [ICTP, Trieste

2017-05-09

If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \\emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\

Effects of neutrino oscillations on nucleosynthesis and neutrino signals for an 18 M⊙ supernova model

Science.gov (United States)

Wu, Meng-Ru; Qian, Yong-Zhong; Martínez-Pinedo, Gabriel; Fischer, Tobias; Huther, Lutz

2015-03-01

In this paper, we explore the effects of neutrino flavor oscillations on supernova nucleosynthesis and on the neutrino signals. Our study is based on detailed information about the neutrino spectra and their time evolution from a spherically symmetric supernova model for an 18 M⊙ progenitor. We find that collective neutrino oscillations are not only sensitive to the detailed neutrino energy and angular distributions at emission, but also to the time evolution of both the neutrino spectra and the electron density profile. We apply the results of neutrino oscillations to study the impact on supernova nucleosynthesis and on the neutrino signals from a Galactic supernova. We show that in our supernova model, collective neutrino oscillations enhance the production of rare isotopes 138La and 180Ta but have little impact on the ν p -process nucleosynthesis. In addition, the adiabatic Mikheyev-Smirnov-Wolfenstein flavor transformation, which occurs in the C /O and He shells of the supernova, may affect the production of light nuclei such as 7Li and 11B. For the neutrino signals, we calculate the rate of neutrino events in the Super-Kamiokande detector and in a hypothetical liquid argon detector. Our results suggest the possibility of using the time profiles of the events in both detectors, along with the spectral information of the detected neutrinos, to infer the neutrino mass hierarchy.

Search for sterile neutrinos in muon neutrino disappearance mode at FNAL

International Nuclear Information System (INIS)

Anokhina, A.; Dzhatdoev, T.; Morgunova, O.; Roganova, T.; Bagulya, A.; Chernyavskiy, M.; Dalkarov, O.; Mingazheva, R.; Shchedrina, T.; Starkov, N.; Vladymyrov, M.; Benettoni, M.; Dal Corso, F.; Dusini, S.; Lippi, I.; Longhin, A.; Bernardini, P.; Mancarella, G.; Marsella, G.; Brugnera, R.; Garfagnini, A.; Medinaceli, E.; Roda, M.; Sirignano, C.; Calabrese, M.; Fiore, G.; Surdo, A.; Cecchetti, A.; Orecchini, D.; Paoloni, A.; Cecchini, S.; Di Ferdinando, D.; Guerzoni, M.; Laurenti, G.; Mandrioli, G.; Mauri, N.; Patrizii, L.; Pozzato, M.; Sahnoun, Z.; Sirri, G.; Togo, V.; Del Prete, A.; Papadia, G.; De Robertis, G.; Fini, R.A.; Loddo, F.; Pastore, A.; De Serio, M.; Paparella, L.; Simone, S.; Klicek, B.; Jakovcic, K.; Malenica, M.; Stipcevic, M.; Kose, U.; Nessi, M.; Margiotta, A.; Pasqualini, L.; Spurio, M.; Muciaccia, M.T.; Polukhina, N.; Rosa, G.; Stanco, L.; Tenti, M.

2017-01-01

The NESSiE Collaboration has been setup to undertake a conclusive experiment to clarify the muon-neutrino disappearance measurements at short baselines in order to put severe constraints to models with more than the three-standard neutrinos. To this aim the current FNAL-Booster neutrino beam for a Short-Baseline experiment was carefully evaluated by considering the use of magnetic spectrometers at two sites, near and far ones. The detector locations were studied, together with the achievable performances of two OPERA-like spectrometers. The study was constrained by the availability of existing hardware and a time-schedule compatible with the undergoing project of multi-site Liquid-Argon detectors at FNAL. The settled physics case and the kind of proposed experiment on the Booster neutrino beam would definitively clarify the existing tension between the ν μ disappearance and the ν e appearance/disappearance at the eV mass scale. In the context of neutrino oscillations the measurement of ν μ disappearance is a robust and fast approach to either reject or discover new neutrino states at the eV mass scale. We discuss an experimental program able to extend by more than one order of magnitude (for neutrino disappearance) and by almost one order of magnitude (for antineutrino disappearance) the present range of sensitivity for the mixing angle between standard and sterile neutrinos. These extensions are larger than those achieved in any other proposal presented so far. (orig.)

Search for sterile neutrinos in muon neutrino disappearance mode at FNAL

Science.gov (United States)

Anokhina, A.; Bagulya, A.; Benettoni, M.; Bernardini, P.; Brugnera, R.; Calabrese, M.; Cecchetti, A.; Cecchini, S.; Chernyavskiy, M.; Dal Corso, F.; Dalkarov, O.; Del Prete, A.; De Robertis, G.; De Serio, M.; Di Ferdinando, D.; Dusini, S.; Dzhatdoev, T.; Fini, R. A.; Fiore, G.; Garfagnini, A.; Guerzoni, M.; Klicek, B.; Kose, U.; Jakovcic, K.; Laurenti, G.; Lippi, I.; Loddo, F.; Longhin, A.; Malenica, M.; Mancarella, G.; Mandrioli, G.; Margiotta, A.; Marsella, G.; Mauri, N.; Medinaceli, E.; Mingazheva, R.; Morgunova, O.; Muciaccia, M. T.; Nessi, M.; Orecchini, D.; Paoloni, A.; Papadia, G.; Paparella, L.; Pasqualini, L.; Pastore, A.; Patrizii, L.; Polukhina, N.; Pozzato, M.; Roda, M.; Roganova, T.; Rosa, G.; Sahnoun, Z.; Shchedrina, T.; Simone, S.; Sirignano, C.; Sirri, G.; Spurio, M.; Stanco, L.; Starkov, N.; Stipcevic, M.; Surdo, A.; Tenti, M.; Togo, V.; Vladymyrov, M.

2017-01-01

The NESSiE Collaboration has been setup to undertake a conclusive experiment to clarify the muon-neutrino disappearance measurements at short baselines in order to put severe constraints to models with more than the three-standard neutrinos. To this aim the current FNAL-Booster neutrino beam for a Short-Baseline experiment was carefully evaluated by considering the use of magnetic spectrometers at two sites, near and far ones. The detector locations were studied, together with the achievable performances of two OPERA-like spectrometers. The study was constrained by the availability of existing hardware and a time-schedule compatible with the undergoing project of multi-site Liquid-Argon detectors at FNAL. The settled physics case and the kind of proposed experiment on the Booster neutrino beam would definitively clarify the existing tension between the ν _{μ } disappearance and the ν e appearance/disappearance at the eV mass scale. In the context of neutrino oscillations the measurement of ν _{μ } disappearance is a robust and fast approach to either reject or discover new neutrino states at the eV mass scale. We discuss an experimental program able to extend by more than one order of magnitude (for neutrino disappearance) and by almost one order of magnitude (for antineutrino disappearance) the present range of sensitivity for the mixing angle between standard and sterile neutrinos. These extensions are larger than those achieved in any other proposal presented so far.

Search for sterile neutrinos in muon neutrino disappearance mode at FNAL

Energy Technology Data Exchange (ETDEWEB)

Anokhina, A.; Dzhatdoev, T.; Morgunova, O.; Roganova, T. [Lomonosov Moscow State University (MSU SINP), Moscow (Russian Federation); Bagulya, A.; Chernyavskiy, M.; Dalkarov, O.; Mingazheva, R.; Shchedrina, T.; Starkov, N.; Vladymyrov, M. [Lebedev Physical Institute of Russian Academy of Sciences, Moscow (Russian Federation); Benettoni, M.; Dal Corso, F.; Dusini, S.; Lippi, I.; Longhin, A. [INFN, Sezione di Padova, Padua (Italy); Bernardini, P.; Mancarella, G.; Marsella, G. [Universita del Salento, Dipartimento di Matematica e Fisica, Lecce (Italy); INFN, Sezione di Lecce, Lecce (Italy); Brugnera, R.; Garfagnini, A.; Medinaceli, E.; Roda, M.; Sirignano, C. [INFN, Sezione di Padova, Padua (Italy); Universita di Padova, Dipartimento di Fisica e Astronomia, Padua (Italy); Calabrese, M.; Fiore, G.; Surdo, A. [INFN, Sezione di Lecce, Lecce (Italy); Cecchetti, A.; Orecchini, D.; Paoloni, A. [INFN, Laboratori Nazionali di Frascati, Frascati, RM (Italy); Cecchini, S.; Di Ferdinando, D.; Guerzoni, M.; Laurenti, G.; Mandrioli, G.; Mauri, N.; Patrizii, L.; Pozzato, M.; Sahnoun, Z.; Sirri, G.; Togo, V. [INFN, Sezione di Bologna, Bologna (Italy); Del Prete, A.; Papadia, G. [INFN, Sezione di Lecce, Lecce (Italy); Universita del Salento, Dipartimento di Ingegneria dell' Innovazione, Lecce (Italy); De Robertis, G.; Fini, R.A.; Loddo, F.; Pastore, A. [INFN, Sezione di Bari, Bari (Italy); De Serio, M.; Paparella, L.; Simone, S. [INFN, Sezione di Bari, Bari (Italy); Universita di Bari, Dipartimento di Fisica, Bari (Italy); Klicek, B.; Jakovcic, K.; Malenica, M.; Stipcevic, M. [Rudjer Boskovic Institute, Zagreb (Croatia); Kose, U.; Nessi, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Margiotta, A.; Pasqualini, L.; Spurio, M. [INFN, Sezione di Bologna, Bologna (Italy); Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy); Muciaccia, M.T. [Universita di Bari, Dipartimento di Fisica, Bari (Italy); Polukhina, N. [Lebedev Physical Institute of Russian Academy of Sciences, Moscow (Russian Federation); National Research Nuclear University MEPhI, Moscow (Russian Federation); Rosa, G. [INFN, Sezione di Roma, Rome (Italy); Stanco, L. [INFN, Sezione di Padova, Padua (Italy); Tenti, M. [Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy); NFN-CNAF, Bologna (Italy)

2017-01-15

The NESSiE Collaboration has been setup to undertake a conclusive experiment to clarify the muon-neutrino disappearance measurements at short baselines in order to put severe constraints to models with more than the three-standard neutrinos. To this aim the current FNAL-Booster neutrino beam for a Short-Baseline experiment was carefully evaluated by considering the use of magnetic spectrometers at two sites, near and far ones. The detector locations were studied, together with the achievable performances of two OPERA-like spectrometers. The study was constrained by the availability of existing hardware and a time-schedule compatible with the undergoing project of multi-site Liquid-Argon detectors at FNAL. The settled physics case and the kind of proposed experiment on the Booster neutrino beam would definitively clarify the existing tension between the ν{sub μ} disappearance and the ν{sub e} appearance/disappearance at the eV mass scale. In the context of neutrino oscillations the measurement of ν{sub μ} disappearance is a robust and fast approach to either reject or discover new neutrino states at the eV mass scale. We discuss an experimental program able to extend by more than one order of magnitude (for neutrino disappearance) and by almost one order of magnitude (for antineutrino disappearance) the present range of sensitivity for the mixing angle between standard and sterile neutrinos. These extensions are larger than those achieved in any other proposal presented so far. (orig.)

The Smell of Relics: Authenticating Saintly Bones and the Role of Scent in the Sensory Experience of Medieval Christian Veneration

Directory of Open Access Journals (Sweden)

Paul Anthony Brazinski

2013-09-01

Full Text Available ''The archaeology of smell is a burgeoning field in recent scholarship. This paper adds to existing literature by investigating the function of smell in relation to relic sales and veneration in medieval Europe, a hitherto understudied area of research. Collating historical texts concerning the translatio of saintly relics in Western Europe and the Byzantine Empire with archaeological sources associated with relic veneration and religious worship (including ampullae, unguentaria, sarcophagi, holy oils, pillow graves, and silk, this paper suggests that (1 smell was used in the medieval world as a means to challenge or confirm a relic’s authenticity, and (2 olfactory liquids that imbued or permeated material objects in the context of worship functioned as a means of focusing attention on relic veneration and were an essential part of the cult and/or pilgrimage experience.

Explaining the 3.5 keV X-ray line in a Lμ‑Lτ extension of the inert doublet model

Science.gov (United States)

Biswas, Anirban; Choubey, Sandhya; Covi, Laura; Khan, Sarif

2018-02-01

We explain the existence of neutrino masses and their flavour structure, dark matter relic abundance and the observed 3.5 keV X-ray line within the framework of a gauged U(1)Lμ ‑ Lτ extension of the "scotogenic" model. In the U(1)Lμ ‑ Lτ symmetric limit, two of the RH neutrinos are degenerate in mass, while the third is heavier. The U(1)Lμ ‑ Lτ symmetry is broken spontaneously. Firstly, this breaks the μ‑τ symmetry in the light neutrino sector. Secondly, this results in mild splitting of the two degenerate RH neutrinos, with their mass difference given in terms of the U(1)Lμ ‑ Lτ breaking parameter. Finally, we get a massive Zμτ gauge boson. Due to the added Z2 symmetry under which the RH neutrinos and the inert doublet are odd, the canonical Type-I seesaw is forbidden and the tiny neutrino masses are generated radiatively at one loop. The same Z2 symmetry also ensures that the lightest RH neutrino is stable and the other two can only decay into the lightest one. This makes the two nearly-degenerate lighter neutrinos a two-component dark matter, which in our model are produced by the freeze-in mechanism via the decay of the Zμτ gauge boson in the early universe. We show that the next-to-lightest RH neutrino has a very long lifetime and decays into the lightest one at the present epoch explaining the observed 3.5 keV line.

Exploring new features of neutrino oscillations with very low energy monoenergetic neutrinos

CERN Document Server

Vergados, J D

2010-01-01

In the present work we propose to study neutrino oscillations employing sources of monoenergetic neutrinos following electron capture by the nucleus. Since the neutrino energy is very low the smaller of the two oscillation lengths, L23, appearing in this electronic neutrino disappearance experiment can be so small that the full oscillation can take place inside the detector and one may determine very accurately the neutrino oscillation parameters. Since in this case the oscillation probability is proportional to theta13, one can measure or set a better limit on the unknown parameter theta13. This is quite important, since, if this mixing angle vanishes, there is not going to be CP violation in the leptonic sector. The best way to detect it is by measuring electron recoils in neutrino-electron scattering. One, however, has to pay the price that the expected counting rates are very small. Thus one needs a very intensive neutrino source and a large detector with as low as possible energy threshold and high energ...

Neutrino burst from SN1987A and the solar-neutrino puzzle

International Nuclear Information System (INIS)

Arafune, J.; Fukugita, M.; Yanagida, T.; Yoshimura, M.

1987-01-01

The prompt ν/sub e/ signal from the supernova explosion in the Large Magellanic Cloud presumably detected by Kamiokande II does not necessarily mean that the Mikheyev-Smirnov-Wolfenstein effect on the solar-neutrino flux is not operative. The electron neutrino, once rotated to a different-flavor neutrino in the progenitor star, can come back via the matter-oscillation effect in the Earth, or a residual ν/sub e/ flux from the progenitor can directly hit the detector, saving the Mikheyev-Smirnov-Wolfenstein explanation of the solar-neutrino problem for a range of mixing parameters

Beam and experiments summary [neutrino studies

CERN Document Server

Blondel, A; Campanelli, M; Cervera-Villanueva, Anselmo; Cline, David B; Collot, J; De Jong, M; Donini, Andrea; Dydak, Friedrich; Edgecock, R; Gavela-Legazpi, Maria Belen; Gómez-Cadenas, J J; González-Garciá, M Concepción; Gruber, P; Harris, D A; Hernández, Pilar; Kuno, Y; Litchfield, P J; McFarland, K; Mena, O; Migliozzi, P; Palladino, Vittorio; Panman, J; Papadopoulos, I M; Para, A; Peña-Garay, C; Pérez, P; Rigolin, Stefano; Romanino, Andrea; Rubbia, André; Strolin, P; Wojcicki, S G

2000-01-01

The discovery of neutrino oscillations marks a major milestone in the history of neutrino physics, and opens a new window to the still mysterious origin of masses and flavour mixing. Many current and forthcoming experiments will. Answer open questions; however, a major step forward, up to and possibly including CP violation in the neutrino-mixing matrix, requires the neutrino beams from a neutrino factory. The neutrino factory is a new concept for producing neutrino beams of unprecedented quality in terms of intensity, flavour composition, and precision of the beam parameters. Most importantly, the neutrino factory is the only known way to generate a high- intensity beam of electron neutrinos of high energy. The neutrino beam from a neutrino factory, in particular the electron-neutrino beam, enables the exploration of otherwise inaccessible domains in neutrino oscillation physics by exploiting baselines of planetary dimensions. Suitable detectors pose formidable challenges but seem within reach with only mode...

Solar neutrinos as a probe of dark matter-neutrino interactions

Energy Technology Data Exchange (ETDEWEB)

Capozzi, Francesco; Vecchi, Luca [Dipartimento di Fisica e Astronomia, Università di Padova, via Marzolo 8, I-35131 Padova (Italy); Shoemaker, Ian M., E-mail: capozzi.12@osu.edu, E-mail: ian.shoemaker@usd.edu, E-mail: vecchi@infn.pd.it [Department of Physics, University of South Dakota, Vermillion, SD 57069 (United States)

2017-07-01

Sterile neutrinos at the eV scale have long been studied in the context of anomalies in short baseline neutrino experiments. Their cosmology can be made compatible with our understanding of the early Universe provided the sterile neutrino sector enjoys a nontrivial dynamics with exotic interactions, possibly providing a link to the Dark Matter (DM) puzzle. Interactions between DM and neutrinos have also been proposed to address the long-standing 'missing satellites' problem in the field of large scale structure formation. Motivated by these considerations, in this paper we discuss realistic scenarios with light steriles coupled to DM . We point out that within this framework active neutrinos acquire an effective coupling to DM that manifests itself as a new matter potential in the propagation within a medium of asymmetric DM . Assuming that at least a small fraction of asymmetric DM has been captured by the Sun, we show that a sizable region of the parameter space of these scenarios can be probed by solar neutrino experiments, especially in the regime of small couplings and light mediators where all other probes become inefficient. In the latter regime these scenarios behave as familiar 3+1 models in all channels except for solar data, where a Solar Dark MSW effect takes place. Solar Dark MSW is characterized by modifications of the most energetic {sup 8}B and CNO neutrinos, whereas the other fluxes remain largely unaffected.

Breaking Be: a sterile neutrino solution to the cosmological lithium problem

Energy Technology Data Exchange (ETDEWEB)

Salvati, L.; Melchiorri, A. [Physics Department and INFN, Università di Roma ' ' La Sapienza' ' , P.le Aldo Moro 2, 00185, Rome (Italy); Pagano, L. [Institut d' Astrophysique Spatiale, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bât. 121, 91405 Orsay cedex (France); Lattanzi, M. [Dipartimento di Fisica e Scienze della Terra, Università di Ferrara and INFN, Sezione di Ferrara, Polo Scientifico e Tecnologico—Edificio C Via Saragat, 1, I-44122 Ferrara (Italy); Gerbino, M., E-mail: laura.salvati@roma1.infn.it, E-mail: lpagano@ias.u-psdu.fr, E-mail: lattanzi@fe.infn.it, E-mail: martina.gerbino@fysik.su.se, E-mail: alessandro.melchiorri@roma1.infn.it [The Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden)

2016-08-01

The possibility that the so-called ''lithium problem'', i.e., the disagreement between the theoretical abundance predicted for primordial {sup 7}Li assuming standard nucleosynthesis and the value inferred from astrophysical measurements, can be solved through a non-thermal Big Bang Nucleosynthesis (BBN) mechanism has been investigated by several authors. In particular, it has been shown that the decay of a MeV-mass particle, like, e.g., a sterile neutrino, decaying after BBN not only solves the lithium problem, but also satisfies cosmological and laboratory bounds, making such a scenario worth to be investigated in further detail. In this paper, we constrain the parameters of the model with the combination of current data, including Planck 2015 measurements of temperature and polarization anisotropies of the Cosmic Microwave Background (CMB), FIRAS limits on CMB spectral distortions, astrophysical measurements of primordial abundances and laboratory constraints. We find that a sterile neutrino with mass M {sub S} = 4.35{sub -0.17}{sup +0.13} MeV (at 95% c.l.), a decay time τ {sub S} = 1.8{sub -1.3}{sup +2.5} · 10{sup 5} s (at 95% c.l.) and an initial density n-bar {sub S} / n-bar {sub cmb} = 1.7{sub -0.6}{sup +3.5} · 10{sup -4} (at 95% c.l.) in units of the number density of CMB photons, perfectly accounts for the difference between predicted and observed {sup 7}Li primordial abundance. This model also predicts an increase of the effective number of relativistic degrees of freedom at the time of CMB decoupling Δ N {sub eff}{sup cmb} ≡ N {sub eff}{sup cmb} -3.046 = 0.34{sub -0.14}{sup +0.16} at 95% c.l.. The required abundance of sterile neutrinos is incompatible with the standard thermal history of the Universe, but could be realized in a low reheating temperature scenario. We also provide forecasts for future experiments finding that the combination of measurements from the COrE+ and PIXIE missions will allow to significantly reduce the

Big-Bang nucleosynthesis and lithium abundance

International Nuclear Information System (INIS)

Singh, Vinay; Lahiri, Joydev; Bhowmick, Debasis; Basu, D.N.

2017-01-01

The predictions of the standard big-bang nucleosynthesis (BBN) theory depend on the astrophysical nuclear reaction rates and on additional three parameters, the number of flavours of light neutrinos, the neutron lifetime and the baryon-to-photon ratio in the uni- verse. The effect of the modification of thirty-five reaction rates on light element abundance yields in BBN was investigated earlier by us. In the present work we have replaced the neutron lifetime, baryon-to-photon ratio by the most recent values and further modified 3 He( 4 He,γ) 7 Be reaction rate which is used directly for estimating the formation of 7 Li as a result of β + decay by the most recent equation. We find that these modifications reduce the calculated abundance of 7 Li by ∼ 12%

Minimalistic Neutrino Mass Model

CERN Document Server

De Gouvêa, A; Gouvea, Andre de

2001-01-01

We consider the simplest model which solves the solar and atmospheric neutrino puzzles, in the sense that it contains the smallest amount of beyond the Standard Model ingredients. The solar neutrino data is accounted for by Planck-mass effects while the atmospheric neutrino anomaly is due to the existence of a single right-handed neutrino at an intermediate mass scale between 10^9 GeV and 10^14 GeV. Even though the neutrino mixing angles are not exactly predicted, they can be naturally large, which agrees well with the current experimental situation. Furthermore, the amount of lepton asymmetry produced in the early universe by the decay of the right-handed neutrino is very predictive and may be enough to explain the current baryon-to-photon ratio if the right-handed neutrinos are produced out of thermal equilibrium. One definitive test for the model is the search for anomalous seasonal effects at Borexino.

Pathlength distributions of atmospheric neutrinos

Energy Technology Data Exchange (ETDEWEB)

Gaisser, T.K.; Stanev, Todor

1999-01-01

We discuss the distribution of the production heights of atmospheric neutrinos as a function of zenith angle and neutrino energy. The distributions can be used as the input for evaluation of neutrino propagation under various hypotheses for neutrino flavor oscillations. Their use may alter substantially the estimates of the oscillation parameters for almost horizontal atmospheric neutrinos.

NEUTRINO mass textures and the nature of new physics implied by present neutrino data

International Nuclear Information System (INIS)

Mohapatra, R.N.

1997-01-01

If all the indications for neutrino oscillations observed in the solar, atmospheric neutrino data as well as in the LSND experiment are borned out by the ongoing and future experiments, then they severely constrain the neutrino mass texture. In particular, the need for an extra ultra-light sterile neutrino species is hard to avoid. Such an extra neutrino has profound implication not only for physics beyond the standard model but even perhaps for physics beyond conventional grand unification. A scenario involving a parallel (or shadow) universe that interacts with the familiar universe only via the gravitational interactions where the ultra-lightness of the sterile neutrino follows from the same physics that explains the near masslessness of the familiar neutrinos is discussed in the presentation

EXPLOSIVE NUCLEOSYNTHESIS IN THE NEUTRINO-DRIVEN ASPHERICAL SUPERNOVA EXPLOSION OF A NON-ROTATING 15 Msun STAR WITH SOLAR METALLICITY

International Nuclear Information System (INIS)

Fujimoto, Shin-ichiro; Kotake, Kei; Hashimoto, Masa-aki; Ono, Masaomi; Ohnishi, Naofumi

2011-01-01

We investigate explosive nucleosynthesis in a non-rotating 15 M sun star with solar metallicity that explodes by a neutrino-heating supernova (SN) mechanism aided by both standing accretion shock instability (SASI) and convection. To trigger explosions in our two-dimensional hydrodynamic simulations, we approximate the neutrino transport with a simple light-bulb scheme and systematically change the neutrino fluxes emitted from the protoneutron star. By a post-processing calculation, we evaluate abundances and masses of the SN ejecta for nuclei with a mass number ≤70, employing a large nuclear reaction network. Aspherical abundance distributions, which are observed in nearby core-collapse SN remnants, are obtained for the non-rotating spherically symmetric progenitor, due to the growth of a low-mode SASI. The abundance pattern of the SN ejecta is similar to that of the solar system for models whose masses range between (0.4-0.5) M sun of the ejecta from the inner region (≤10, 000 km) of the precollapse core. For the models, the explosion energies and the 56 Ni masses are ≅ 10 51 erg and (0.05-0.06) M sun , respectively; their estimated baryonic masses of the neutron star are comparable to the ones observed in neutron-star binaries. These findings may have little uncertainty because most of the ejecta is composed of matter that is heated via the shock wave and has relatively definite abundances. The abundance ratios for Ne, Mg, Si, and Fe observed in the Cygnus loop are reproduced well with the SN ejecta from an inner region of the 15 M sun progenitor.

Neutrino cosmology

CERN Document Server

Lesgourgues, Julien; Miele, Gennaro; Pastor, Sergio

2013-01-01

The role that neutrinos have played in the evolution of the Universe is the focus of one of the most fascinating research areas that has stemmed from the interplay between cosmology, astrophysics and particle physics. In this self-contained book, the authors bring together all aspects of the role of neutrinos in cosmology, spanning from leptogenesis to primordial nucleosynthesis, their role in CMB and structure formation, to the problem of their direct detection. The book starts by guiding the reader through aspects of fundamental neutrino physics, such as the standard cosmological model and the statistical mechanics in the expanding Universe, before discussing the history of neutrinos in chronological order from the very early stages until today. This timely book will interest graduate students and researchers in astrophysics, cosmology and particle physics, who work with either a theoretical or experimental focus.

Supernova neutrinos

International Nuclear Information System (INIS)

John Beacom

2003-01-01

We propose that neutrino-proton elastic scattering, ν + p → ν + p, can be used for the detection of supernova neutrinos. Though the proton recoil kinetic energy spectrum is soft, with T p ≅ 2E ν 2 /M p , and the scintillation light output from slow, heavily ionizing protons is quenched, the yield above a realistic threshold is nearly as large as that from (bar ν) e + p → e + + n. In addition, the measured proton spectrum is related to the incident neutrino spectrum, which solves a long-standing problem of how to separately measure the total energy release and temperature of ν μ , ν τ , (bar ν) μ , and (bar ν) τ . The ability to detect this signal would give detectors like KamLAND and Borexino a crucial and unique role in the quest to detect supernova neutrinos

Neutrino Factory: status and prospects

International Nuclear Information System (INIS)

Long, K.

2011-01-01

The properties of the neutrino provide a unique window on physics beyond that described by the Standard Model. The study of sub-leading effects in neutrino oscillations has begun with the race to measure θ 13 consensus is emerging within the international community that a novel neutrino source is required to allow sensitive searches for leptonic CP violation to be carried out and the neutrino mass-hierarchy to be determined. The Neutrino Factory, in which intense neutrino beams are produced from the decay of muons, has been shown to out-perform the other proposed facilities. The physics case for the Neutrino Factory will be reviewed and the baseline design of the facility being developed by the International Design Study for the Neutrino Factory (the IDS-NF) collaboration will be described.

Steps towards the Neutrino Factory

International Nuclear Information System (INIS)

Long, K.

2012-01-01

The properties of the neutrino provide a unique window on physics beyond that described by the Standard Model. The study of sub-leading effects in neutrino oscillations has begun with the race to measure θ 13 . A consensus is emerging within the international community that a novel neutrino source is required to allow sensitive searches for leptonic CP violation to be carried out and the neutrino mass-hierarchy to be determined. The Neutrino Factory, in which intense neutrino beams are produced from the decay of muons, has been shown to out-perform the other proposed facilities. The physics case for the Neutrino Factory will be reviewed and the baseline design of the facility being developed by the International Design Study for the Neutrino Factory (the IDS-NF) collaboration will be described.

Neutrino masses and mixings

International Nuclear Information System (INIS)

Wolfenstein, L.

1991-01-01

Theoretical prejudices, cosmology, and neutrino oscillation experiments all suggest neutrino mass are far below present direct experimental limits. Four interesting scenarios and their implications are discussed: (1) a 17 keV ν τ , (2) a 30 ev ν τ making up the dark matter, (3) a 10 -3 ev ν μ to solve the solar neutrino problem, and (4) a three-neutrino MSW solution

Calculation of low-energy reactor neutrino spectra reactor for reactor neutrino experiments

Energy Technology Data Exchange (ETDEWEB)

Riyana, Eka Sapta; Suda, Shoya; Ishibashi, Kenji; Matsuura, Hideaki [Dept. of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Kyushu (Japan); Katakura, Junichi [Dept. of Nuclear System Safety Engineering, Nagaoka University of Technology, Nagaoka (Japan)

2016-06-15

Nuclear reactors produce a great number of antielectron neutrinos mainly from beta-decay chains of fission products. Such neutrinos have energies mostly in MeV range. We are interested in neutrinos in a region of keV, since they may take part in special weak interactions. We calculate reactor antineutrino spectra especially in the low energy region. In this work we present neutrino spectrum from a typical pressurized water reactor (PWR) reactor core. To calculate neutrino spectra, we need information about all generated nuclides that emit neutrinos. They are mainly fission fragments, reaction products and trans-uranium nuclides that undergo negative beta decay. Information in relation to trans-uranium nuclide compositions and its evolution in time (burn-up process) were provided by a reactor code MVP-BURN. We used typical PWR parameter input for MVP-BURN code and assumed the reactor to be operated continuously for 1 year (12 months) in a steady thermal power (3.4 GWth). The PWR has three fuel compositions of 2.0, 3.5 and 4.1 wt% {sup 235}U contents. For preliminary calculation we adopted a standard burn-up chain model provided by MVP-BURN. The chain model treated 21 heavy nuclides and 50 fission products. The MVB-BURN code utilized JENDL 3.3 as nuclear data library. We confirm that the antielectron neutrino flux in the low energy region increases with burn-up of nuclear fuel. The antielectron-neutrino spectrum in low energy region is influenced by beta emitter nuclides with low Q value in beta decay (e.g. {sup 241}Pu) which is influenced by burp-up level: Low energy antielectron-neutrino spectra or emission rates increase when beta emitters with low Q value in beta decay accumulate. Our result shows the flux of low energy reactor neutrinos increases with burn-up of nuclear fuel.

Properties of neutrinos: Recent results

International Nuclear Information System (INIS)

Robertson, R.G.H.

1987-01-01

Recent progress in experimental determinations of the properties of neutrinos is summarized. In particular, the extensive work on direct kinematic measurements of neutrino mass, on neutrino counting and on neutrino oscillations is highlighted. It is concluded that there may already be sufficient information to fix the masses of the neutrinos, but the evidence is still far from convincing. 63 refs., 13 figs

Neutrino magnetic moment contribution to the neutrino-deuteron reaction

International Nuclear Information System (INIS)

Tsuji, K.; Nakamura, S.; Sato, T.; Kubodera, K.; Myhrer, F.

2004-01-01

We study the effect of the neutrino magnetic moment on the neutrino-deuteron breakup reaction, using a method called the standard nuclear physics approach, which has already been well tested for several electroweak processes involving the deuteron

Neutrino conversion in a neutrino flux: towards an effective theory of collective oscillations

Science.gov (United States)

Hansen, Rasmus S. L.; Smirnov, Alexei Yu.

2018-04-01

Collective oscillations of supernova neutrinos above the neutrino sphere can be completely described by the propagation of individual neutrinos in external potentials and are in this sense a linear phenomenon. An effective theory of collective oscillations can be developed based on certain assumptions about time dependence of these potentials. General conditions for strong flavor transformations are formulated and these transformations can be interpreted as parametric resonance effects induced by periodic modulations of the potentials. We study a simplified and solvable example, where a probe neutrino is propagating in a flux of collinear neutrinos, such that ν ν‑ interactions in the flux are absent. Still, this example retains the main feature—the coherent flavor exchange. Properties of the parametric resonance are studied, and it is shown that integrations over energies and emission points of the flux neutrinos suppress modulations of the potentials and therefore strong transformations. The transformations are also suppressed by changes in densities of background neutrinos and electrons.

Workshop on low energy neutrino physics

International Nuclear Information System (INIS)

2009-01-01

The main topics of the workshop are: the determination of the neutrino mixing angle theta-13, the experiments concerning the monitoring of reactors based on the measurement of neutrino spectra, solar neutrinos, supernovae neutrinos, geo-neutrinos, neutrino properties, neutrinoless double beta decay and future low energy neutrino detectors. This document gathers together the program of the workshop, the slides of the presentations, some abstracts and some posters

CERN: Neutrino facelift

Energy Technology Data Exchange (ETDEWEB)

Anon.

1991-11-15

With the termination this summer of the CHARM II neutrino experiment at the SPS proton synchrotron, CERN's 30- year tradition of neutrino physics came to a temporary halt. However with these enigmatic particles playing a vital role in today's Standard Model but continually reluctant to give up all their secrets, neutrino physics will continue to be in the forefront of this research.

GRAN SASSO/GRENOBLE: Artificial neutrino source confirms solar neutrino result

International Nuclear Information System (INIS)

Anon.

1995-01-01

In 1992, the Gallex experiment announced the first observation of the neutrinos produced in the primary proton-proton fusion reaction in the core of the Sun, reaction at the origin of the energy production by our star (September 1992, page 1). The Gallex team stressed that the observed neutrino flux was only about two-thirds of the predicted level, confirming the deficit observed by the two pioneering experiments, Ray Davis' chlorine-based detector in the USA and the Kamiokande study in Japan (which are only sensitive to neutrinos from subsidiary solar fusion processes). This deficit demands explanation, and could considerably modify our understanding of how stars shine and/or of neutrino physics. But before drawing conclusions, the Gallex result had to be checked. Gallex, installed in the Italian Gran Sasso underground Laboratory, is a radiochemical experiment using neutrino interactions to transform gallium-71 into germanium-71. The latter is radioactive and decays with a half-life of 11.4 days. Counting the germanium-71 atoms extracted from the target tank measures the neutrino flux to which the detector is exposed. Neutrinos are famous for their reluctance to interact. 65 billion per square centimetre per second on the surface of the Earth produce only one germanium-71 atom in the Gallex target containing 30 tons of gallium. This is at the limit of homeopathy (extracting few atoms of germanium-71 from a solution containing 10 30 atoms) and needs careful checking. Since it is not possible to switch off the Sun, the only recourse was to build an artificial neutrino source more powerful than the Sun as a benchmark. This was done last summer. Last May, 36 kilograms of chromium grains were placed in the Siloe reactor of the French Commissariat à l'énergie atomique, Grenoble. The chromium had been previously enriched to 40% chromium-50 by the Kurchatov Institute in Moscow (natural chromium contains only 4.5% chromium-50). A dedicated core was built for

Neutrino Oscillation Experiment at JHF

CERN Multimedia

2002-01-01

T2K is a long baseline neutrino experiment designed to investigate how neutrinos change from one flavor to another as they travel (neutrino oscillations). An intense beam of muon neutrinos is generated at the J-PARC nuclear physics site on the East coast of Japan and directed across the country to the Super-Kamiokande neutrino detector in the mountains of western Japan. The beam is measured once before it leaves the J-PARC site, using the near detector ND280, and again at Super-K, 295 km away: the change in the measured intensity and composition of the beam is used to provide information on the properties of neutrinos. The high intensity neutrino beam is produced in an off-axis configuration. The peak neutrino energy is tuned to the oscillation maximum of ∼ 0.6 GeV to maximize the sensitivity to neutrino oscillations. The science goals of T2K can be summarized as follows: •\tsearch for CP violation in the neutrino sector •\tdiscovery of νμ → νe ( i.e. the confirmation that θ13 > 0 ) •\tprecision ...

New phenomena in neutrino physics

International Nuclear Information System (INIS)

Kopp, Joachim

2009-01-01

In this thesis, we discuss two new concepts in neutrino physics: The neutrino Moessbauer effect and non-standard neutrino interactions. We show that neutrinos emitted and absorbed in recoil-free processes (Moessbauer neutrinos) can oscillate in spite of their near monochromaticity. We support this statement by quantum mechanical wave packet arguments and by a quantum field theoretical (QFT) calculation of the combined rate of Moessbauer neutrino emission, propagation and absorption. The QFT approach does not require any a priori assumptions on the neutrino wave function, and it allows us to include a realistic treatment of the different mechanisms leading to broadening of the emission and absorption lines. In the second part of this work, we study the phenomenology of non-standard neutrino interactions (NSI). We classifying the allowed NSI operators according to their impact on future oscillation experiments and present numerical results for the NSI sensitivities of reactor, superbeam and neutrino factory experiments. We point out that NSI could mimic standard oscillation effects, and might therefore lead to incorrect fit values for the oscillation parameters. For the case of the neutrino factory, we perform a detailed optimisation study to determine the optimum muon energy and detector configuration. (orig.)

New phenomena in neutrino physics

Energy Technology Data Exchange (ETDEWEB)

Kopp, Joachim

2009-04-15

In this thesis, we discuss two new concepts in neutrino physics: The neutrino Moessbauer effect and non-standard neutrino interactions. We show that neutrinos emitted and absorbed in recoil-free processes (Moessbauer neutrinos) can oscillate in spite of their near monochromaticity. We support this statement by quantum mechanical wave packet arguments and by a quantum field theoretical (QFT) calculation of the combined rate of Moessbauer neutrino emission, propagation and absorption. The QFT approach does not require any a priori assumptions on the neutrino wave function, and it allows us to include a realistic treatment of the different mechanisms leading to broadening of the emission and absorption lines. In the second part of this work, we study the phenomenology of non-standard neutrino interactions (NSI). We classifying the allowed NSI operators according to their impact on future oscillation experiments and present numerical results for the NSI sensitivities of reactor, superbeam and neutrino factory experiments. We point out that NSI could mimic standard oscillation effects, and might therefore lead to incorrect fit values for the oscillation parameters. For the case of the neutrino factory, we perform a detailed optimisation study to determine the optimum muon energy and detector configuration. (orig.)

Detection of supernova neutrinos by neutrino-proton elastic scattering

International Nuclear Information System (INIS)

Beacom, John F.; Farr, Will M.; Vogel, Petr

2002-01-01

We propose that neutrino-proton elastic scattering, ν+p→ν+p, can be used for the detection of supernova neutrinos in scintillator detectors. Though the proton recoil kinetic energy spectrum is soft, with T p ≅2E ν 2 /M p , and the scintillation light output from slow, heavily ionizing protons is quenched, the yield above a realistic threshold is nearly as large as that from ν(bar sign) e +p→e + +n. In addition, the measured proton spectrum is related to the incident neutrino spectrum, which solves a long-standing problem of how to separately measure the total energy and temperature of ν μ , ν τ , ν(bar sign) μ , and ν(bar sign) τ . The ability to detect this signal would give detectors like KamLAND and Borexino a crucial and unique role in the quest to detect supernova neutrinos

Simulation of coherent nonlinear neutrino flavor transformation in the supernova environment: Correlated neutrino trajectories

Science.gov (United States)

Duan, Huaiyu; Fuller, George M.; Carlson, J.; Qian, Yong-Zhong

2006-11-01

We present results of large-scale numerical simulations of the evolution of neutrino and antineutrino flavors in the region above the late-time post-supernova-explosion proto-neutron star. Our calculations are the first to allow explicit flavor evolution histories on different neutrino trajectories and to self-consistently couple flavor development on these trajectories through forward scattering-induced quantum coupling. Employing the atmospheric-scale neutrino mass-squared difference (|δm2|≃3×10-3eV2) and values of θ13 allowed by current bounds, we find transformation of neutrino and antineutrino flavors over broad ranges of energy and luminosity in roughly the “bi-polar” collective mode. We find that this large-scale flavor conversion, largely driven by the flavor off-diagonal neutrino-neutrino forward scattering potential, sets in much closer to the proto-neutron star than simple estimates based on flavor-diagonal potentials and Mikheyev-Smirnov-Wolfenstein evolution would indicate. In turn, this suggests that models of r-process nucleosynthesis sited in the neutrino-driven wind could be affected substantially by active-active neutrino flavor mixing, even with the small measured neutrino mass-squared differences.

From b → sγ to the LSP detection rates in minimal string unification models

International Nuclear Information System (INIS)

Khalil, S.; Masiero, A.; Shafi, Q.

1997-04-01

We exploit the measured branching ratio for b → sγ to derive lower limits on the sparticle and Higgs masses in the minimal string unification models. For the LSP ('bino'), chargino and the lightest Higgs, these turn out to be 50, 90 and 75 GeV respectively. Taking account of the upper bounds on the mass spectrum from the LSP relic abundance, we estimate the direct detection rate for the latter to vary from 10 -1 to 10 -4 events/kg/day. The muon flux, produced by neutrinos from the annihilating LSP's, varies in the range 10 -2 - 10 -9 muons/m 2 /day. (author). 26 refs, 9 figs

An Experimentalist's Overview of Solar Neutrinos

Science.gov (United States)

Oser, Scott M.

2012-02-01

Four decades of solar neutrino research have demonstrated that solar models do a remarkable job of predicting the neutrino fluxes from the Sun, to the extent that solar neutrinos can now serve as a calibrated neutrino source for experiments to understand neutrino oscillations and mixing. In this review article I will highlight the most significant experimental results, with emphasis on the latest model-independent measurements from the Sudbury Neutrino Observatory. The solar neutrino fluxes are seen to be generally well-determined experimentally, with no indications of time variability, while future experiments will elucidate the lower energy part of the neutrino spectrum, especially pep and CNO neutrinos.

An Experimentalist's Overview of Solar Neutrinos

International Nuclear Information System (INIS)

Oser, Scott M

2012-01-01

Four decades of solar neutrino research have demonstrated that solar models do a remarkable job of predicting the neutrino fluxes from the Sun, to the extent that solar neutrinos can now serve as a calibrated neutrino source for experiments to understand neutrino oscillations and mixing. In this review article I will highlight the most significant experimental results, with emphasis on the latest model-independent measurements from the Sudbury Neutrino Observatory. The solar neutrino fluxes are seen to be generally well-determined experimentally, with no indications of time variability, while future experiments will elucidate the lower energy part of the neutrino spectrum, especially pep and CNO neutrinos.

Leptogenesis and neutrino masses

International Nuclear Information System (INIS)

Pluemacher, M.

2004-01-01

Thermal leptogenesis explains the baryon asymmetry of the universe by the out-of-equilibrium decays of heavy right-handed neutrinos. In the minimal seesaw model this leads to interesting implications for light neutrino properties. In particular, quasi-degenerate light neutrino masses are incompatible with leptogenesis. An upper bound on light neutrino masses of 0.1 eV can be derived, which will be tested by forthcoming laboratory experiments and cosmology. (author)

Status of Heavy Neutrino Experiments

CERN Document Server

Wynne, Benjamin; The ATLAS collaboration

2017-01-01

The observation of neutrino oscillations raises the possibility that there exist additional, undiscovered high-mass neutrinos, giving mass to Standard Model neutrinos via the seesaw mechanism. By pushing the collider energy frontier at the LHC, the possibility arises that these heavy neutrinos may be produced and identified. We summarise the latest LHC results of searches for heavy neutrinos in a variety of final states.

Solar neutrino spectrum, sterile neutrinos and additional radiation in the Universe

International Nuclear Information System (INIS)

Holanda, Pedro Cunha de

2011-01-01

Full text: Recent results from the SNO, Super-Kamiokande and Borexino experiments do not show the expected upturn of the energy spectrum of events (the ratio R ≡ N obs /N SSM ) at low energies. At the same time, cosmological observations testify for possible existence of additional relativistic degrees of freedom in the early Universe: ΔN eff = 1 - 2. These facts strengthen the case of very light sterile neutrino, ν s , with Δm 0 1 2 ∼ (0.7 - 2) . 10 -5 e V 2 , which mixes weakly with the active neutrinos. The ν s mixing in the mass eigenstate ν 1 characterized by sin 2 2∝ ∼ 10 -3 can explain an absence of the upturn. The mixing of ν s in the eigenstate ν 3 with sin 2 β ∼ 0.1 leads to production of ν s via oscillations in the Universe and to additional contribution Δ N eff ∼ 0.7 -1 before the big bang nucleosynthesis and later. Such a mixing can be tested in forthcoming experiments with the atmospheric neutrinos as well as in future accelerator long baseline experiments. It has substantial impact on conversion of the supernova neutrinos. We perform a qualitative and quantitative analysis of solar neutrino data including a fourth neutrino with different mixings with the active neutrino sector.(author)

Neutrino-oscillation search with cosmic-ray neutrinos

International Nuclear Information System (INIS)

Ayres, D.S.; Cortez, B.; Gaisser, T.K.; Mann, A.K.; Shrock, R.E.; Sulak, L.R.

1984-01-01

A sensitive search for neutrino oscillations involving ν/sub e/, ν/sub μ/, and ν/sub tau/ may be provided by measurements of the ratio of the total interaction rates of upward- and downward-going cosmic-ray neutrinos within a massive (approx.10 kton) detector. Assuming mixing between all pairs of ν/sub e/, ν/sub μ/, and ν/sub tau/, the experiment is capable of observing time-averaged probabilities /sub t/ and /sub t/ of magnitude set by mixing strengths corresponding to, e.g., the d- to s-quark mixing strength, and of reaching the limit Δm/sub i/j 2 equivalentVertical Barm/sub i/ 2 -m/sub j/ 2 Vertical Barroughly-equal10 -4 eV 2 , where m/sub i/, and m/sub j/ are neutrino mass eigenstates, and P/sub e/tau and P/sub mutau/ are the probabilities for ν/sub e/ and ν/sub μ/, respectively, to oscillate into ν/sub tau/ after traversing a distance Lroughly-equal diameter of the Earth. Possible ambiguities may be resolved through comparison of the ratios N/sub e//N/sub μ/ for the upward- and downward-going neutrinos

Chaotic amplification of neutrino chemical potentials by neutrino oscillations in big bang nucleosynthesis

International Nuclear Information System (INIS)

Shi, X.

1996-01-01

We investigate in detail the parameter space of active-sterile neutrino oscillations that amplifies neutrino chemical potentials at the epoch of big bang nucleosynthesis. We calculate the magnitude of the amplification and show evidence of chaos in the amplification process. We also discuss the implications of the neutrino chemical potential amplification in big bang nucleosynthesis. It is shown that with a ∼1 eV ν e , the amplification of its chemical potential by active-sterile neutrino oscillations can lower the effective number of neutrino species at big bang nucleosynthesis to significantly below three. copyright 1996 The American Physical Society

Chaotic amplification of neutrino chemical potentials by neutrino oscillations in big bang nucleosynthesis

Energy Technology Data Exchange (ETDEWEB)

Shi, X. [Department of Physics, Queen`s University, Kingston, Ontario, K7L 3N6 (CANADA)

1996-08-01

We investigate in detail the parameter space of active-sterile neutrino oscillations that amplifies neutrino chemical potentials at the epoch of big bang nucleosynthesis. We calculate the magnitude of the amplification and show evidence of chaos in the amplification process. We also discuss the implications of the neutrino chemical potential amplification in big bang nucleosynthesis. It is shown that with a {approximately}1 eV {nu}{sub {ital e}}, the amplification of its chemical potential by active-sterile neutrino oscillations can lower the effective number of neutrino species at big bang nucleosynthesis to significantly below three. {copyright} {ital 1996 The American Physical Society.}

New neutrino oscillation results from NOVA

CERN Multimedia

CERN. Geneva

2018-01-01

Neutrinos oscillate among flavors as they travel because a neutrino of a particular flavor is also a superposition of multiple neutrinos with slightly different masses.  The interferometric nature of oscillations allows these tiny mass differences to be measured, along with the parameters of the PMNS matrix which governs the mixing. However, since neutrinos only interact weakly, a powerful neutrino source and massive detectors are required to measure them. In this talk I will show recently updated results from NOvA, a long-baseline neutrino oscillation experiment at Fermilab with two functionally identical scintillator detectors. I will present measurements of muon neutrino disappearance and electron neutrino appearance, and what constraints those measurements put on the remaining open questions in neutrino oscillations: Is the neutrino mass hierarchy "normal" or "inverted?" Do neutrino oscillations violate CP symmetry? Is the mixing in the atmospheric sector maximal? The recent update includes 50%...

16th International Workshop on Neutrino Factories and Future Neutrino Beam Facilities

CERN Document Server

2015-01-01

These proceedings present the written contributions from participants of the 16th International Workshop on Neutrino Factories and Future Neutrino Beam Facilities (NUFACT 2014) that was held at the University of Glasgow (Glasgow, Scotland, United Kingdom) from 25-30 August 2014. This edition of the NUFACT annual meetings, which started in 1999, consisted of 24 plenary and 92 parallel talks and various poster sessions, with the participation of 124 delegates. Furthermore, the International Neutrino Summer School 2014 was held from 10-22 August 2014 at St Andrews, Scotland, in the two weeks before NUFACT 2014. It was intended for young scientists with an interest in neutrino physics in such a way that they would be able to participate and contribute to the NUFACT workshop as well. The objectives of the NUFACT workshops are to review progress on different studies for future accelerator-based neutrino oscillation facilities, with the goal to discover the mass hierarchy of neutrinos, CP violation in the leptonic s...

Neutrinos in astrophysics

CERN Document Server

Rees, Martin J

1980-01-01

The amount of 4He synthesised in the "big bang" is sensitive to the early particle content and to the expansion rate. If there was indeed a "big bang", surprisingly strong conclusions can be drawn about the number of species of neutrinos, and about the possibility that such particles have non-zero rest mass. The dynamics of supernovae are sensitive to the det~ils of neutrino physics; such explosions would yield IO L-1053 ergs of -v IO Mev neutrinos, in a burst lasting a few milliseconds. Galactic nuclei, cosmic ray sources and other high energy cosmic phenomena could yield a low background of~ 10 Gev neutrinos.

Neutrinos in supernovae

International Nuclear Information System (INIS)

Cooperstein, J.

1986-10-01

The role of neutrinos in Type II supernovae is discussed. An overall view of the neutrino luminosity as expected theoretically is presented. The different weak interactions involved are assessed from the standpoint of how they exchange energy, momentum, and lepton number. Particular attention is paid to entropy generation and the path to thermal and chemical equilibration, and to the phenomenon of trapping. Various methods used to calculate the neutrino flows are considered. These include trapping and leakage schemes, distribution-averaged transfer, and multi-energy group methods. The information obtained from the neutrinos caught from Supernova 1987a is briefly evaluated. 55 refs., 7 figs

A search for matter enhanced neutrino oscillations through measurements of day and night solar neutrino fluxes at the Sudbury Neutrino Observatory

Science.gov (United States)

Miknaitis, Kathryn Kelly Schaffer

The Sudbury Neutrino Observatory (SNO) is a heavy-water Cherenkov detector designed to study 8B neutrinos from the sun. Through the charged-current (CC) and neutral-current (NC) reactions of neutrinos on deuterium, SNO separately determines the flux of electron neutrinos and the flux of all active flavors of solar 8B neutrinos. SNO is also sensitive to the elastic scattering (ES) of neutrinos on electrons in the heavy water. Measurements of the CC and NC rates in SNO have conclusively demonstrated solar neutrino flavor change. This flavor change is believed to be caused by matter-enhanced oscillations in the sun, through the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Matter effects could also change the flavor composition of neutrinos that traverse the earth. A comparison of the day and night measured CC flux at SNO directly tests for the MSW effect and contributes to constraints on neutrino oscillation parameters in the MSW model. We perform measurements of the day and night neutrino fluxes using data from the second phase of SNO, in which salt (NaCl) was added to the heavy water to enhance sensitivity to the NC reaction. Better discrimination between CC and NC events in the salt phase allows the fluxes to be determined without constraining the neutrino energy spectrum. The day-night asymmetry in the CC flux measured in this model-independent analysis is ACC = [-5.6 +/- 7.4(stat.) +/- 5.3(syst.)]%, where the asymmetry is defined as the difference between the night and day values divided by their average. The asymmetries in the NC and ES fluxes are ANC = [4.2 +/- 8.6(stat.) +/- 7.2(syst.)]%, and AES = (14.6 +/- 19.8(stat.) +/- 3.3(syst.)]%. The neutral current asymmetry is expected to be zero assuming standard neutrino oscillations. When we constrain it to be zero, we obtain ACC = [-3.7 +/- 6.3(stat.) +/- 3.2(syst.)]% and AES = [15.3 +/- 19.8(stat.) +/- 3.0(syst.)]%. The day and night energy spectra from the CC reaction have been measured and show no evidence for

The Sudbury neutrino observatory

International Nuclear Information System (INIS)

McLatchie, W.; Earle, E.D.

1987-08-01

This report initially discusses the Homestake Mine Experiment, South Dakota, U.S.A. which has been detecting neutrinos in 38 x 10 litre vats of cleaning fluid containing chlorine since the 1960's. The interation between neutrinos and chlorine produces argon so the number of neutrinos over time can be calculated. However, the number of neutrinos which have been detected represent only one third to one quarter of the expected number i.e. 11 per month rather than 48. It is postulated that the electron-neutrinos originating in the solar core could change into muon- or tau-neutrinos during passage through the high electron densities of the sun. The 'low' results at Homestake could thus be explained by the fact that the experiment is only sensitive to electron-neutrinos. The construction of a heavy water detector is therefore proposed as it would be able to determine the energy of the neutrinos, their time of arrival at the detector and their direction. It is proposed to build the detector at Creighton mine near Sudbury at a depth of 6800 feet below ground level thus shielding the detector from cosmic rays which would completely obscure the neutrino signals from the detector. The report then discusses the facility itself, the budget estimate and the social and economic impact on the surrounding area. At the time of publication the proposal for the Sudbury Neutrino Observatory was due to be submitted for peer review by Oct. 1, 1987 and then to various granting bodies charged with the funding of scientific research in Canada, the U.S.A. and Britain