INFO 05 Speakers and Abstracts

Kevork Abazajian


Neutrinos and Cosmological Large Scale Structure

Massive neutrinos alter the growth of cosmological large scale  structure and affect the growth of small scale structure through  their clustering at low redshift.   I review the current limits on  neutrino mass from observations of large scale structure and examine  future probes.

Phil Amanik


Neutrino Flavor Changing Neutral Currents and Stellar Collapse

Flavor changing neutral current interactions are predicted in some extensions of the Standard Model. I will discuss a process by which a neutrino can change flavor by scattering with a quark. I will show that when this interaction is included in the stellar collapse model, the dynamics of the core's evolution and outcome of collapse are drastically changed.

Sergei Bashinsky

ICTP, Trieste

Relic Neutrinos in the Cosmic Microwave and Gravitational Backgrounds

Relic neutrinos were abundant in the early universe and left gravitational signatures
on the CMB and primordial gravitational radiation. I will discuss in detail the origin
of these signatures and their robustness or degeneracies with changes of other
cosmological unknowns.

Nicole Bell


Cosmological Signatures of Neutrino Interactions

We consider the consequences for the relic neutrino abundance if extra neutrinos interactions are allowed, for example, the coupling of the neutrinos to a light boson.  For a wide range of allowed couplings, the relic neutrinos could annihilate at late times, and thus make a negligible contribution to the matter density today.  This mechanism allows cosmological neutrino mass limits to be evaded.  We also discuss neutrino signatures in the Cosmic Microwave Background, and outline the CMB effects that could distinguish between a free-streaming or interacting fluid of neutrinos.

Cliff Burgess

McGill U. and Perimeter Institute

Neutrino Oscillations and the Cosmological Constant Problem

Supersymmetric Large Extra Dimensions have emerged as a  hopeful new approach to explaining why the Dark Energy density can be small but nonzero in a technically natural way. It does so by introducing new dimensions at micron length scales in a supersymmetric way. The proposal is very predictive, with implications for the LHC and tests of gravity in addition to those for cosmology. This talk briefly summarizes the proposal, and describes some of its possible implications for neutrino physics. In particular, it is shown how the cosmological motivations change the neutrino predictions from what is normally obtained in large-dimensional neutrino models, and shows how these changes help to avoid the bounds which normally preclude successful neutrino model-building within this framework.

Marco Cirelli

Yale U.

Picturing Dark Matter from its neutrinos

Dark Matter particles accumulate in the center of the Earth and the Sun and annihilate, yielding fluxes of high energy neutrinos (~tens of GeV) which will be hopefully detected in the Neutrino Telescopes (Antares, IceCube, a large Cerenkov detector...). The neutrino fluxes carry precious information on the main properties of DM (its abundance, its mass and its annihilation branching ratios), opening windows on its nature and on the theory that explains it.
We compute precisely the expected yield of neutrinos of all flavors and, especially, the neutrino spectra, which are more free from astrophysical uncertainties. We develop the appropriate formalism to follow the neutrino production, the evolution of the fluxes in the matter of the Earth and the Sun (determined by flavor oscillations, absorptions/scatterings and tau regeneration) and in the vacuum and finally several kinds of detection signatures.
We use these results to show how neutrino flavor oscillations have the effect of greatly enhancing or reducing the signal in a detector (depending on the dominant annihilation branching ratio) and, especially, how the measurements of neutrino spectra will allow the reconstruction of the properties of the Dark Matter particles."

Steve Elliott


The Majorana Project

The recent demonstrations of oscillations in the atmospheric and solar neutrino data convincingly indicate that neutrinos do have mass. Those data, however, do not tell us the absolute mass scale but only the differences of the square of the neutrino masses. Even so, we now know that at least one neutrino has a mass of about 50 meV or larger. Studies of double beta decay rates offer hope for determining the absolute mass scale. In particular, zero-neutrino double beta decay can address the issues of lepton number conservation, the particle-antiparticle nature of the neutrino, and its mass. In fact, the next generation of these experiments will be sensitive to neutrino masses in the exciting range below 50 meV. An overview of zero-neutrino double beta decay and its relation to neutrino mass will be discussed followed by a detailed description of the Majorana Project.

Stuart Freedman

UC Berekeley & LBNL

theta_13 at reactors


Javier Ferrandis


QLC relation and neutrino mass hierarchy

Latest measurements have revealed that the deviation from a maximal solar mixing angle is approximately the Cabibbo angle, i.e. QLC relation. Consequently we have calculated the required corrections to the exactly bimaximal neutrino mass matrix ansatz necessary to account for the solar mass difference and the solar mixing angle. We point out that the relative size of these two corrections depends strongly on the hierarchy case under consideration. We find that the inverted hierarchy case with opposite CP parities, which is known to guarantee the RGE stability of the solar mixing angle, offers the most plausible scenario for a high energy origin of a QLC-corrected bimaximal neutrino mass matrix, especially in the context of SUSY GUT models. This possibility may allow us to explain the QLC relation in connection with the origin of the charged fermion mass matrices. We comment on some neutrino mass models recently proposed to explain the QLC relation.

Alexander Friedland


Solar Neutrinos and Neutrino Magnetic Moment


George Fuller


Simultaneous Transformation of Neutrinos and Antineutrinos


André de Gouvea

Northwestern U.

See-Saw Energy Scale and the LSND Anomaly

The most general, renormalizable Lagrangian that includes massive neutrinos contains ``right-handed neutrino'' Majorana masses of order M. While there are prejudices in favor of M much larger than the weak scale, virtually nothing is known about its magnitude. After briefly reviewing the LSND anomaly, I argue that it provides, currently, the only experimental hint: M ~ 1 eV. If this is the case, the LSND mixing angles are functions of the active neutrino masses and mixing and, remarkably, adequate fits to all data can be naturally obtained. I briefly discuss consequences of this ``eV-seesaw'' for supernova neutrino oscillations, tritium beta-decay, neutrinoless double-beta decay, and cosmology.

Andrei Gruzinov


Thermonuclear Reaction Rates in the Sun

The best available  calculation of thermonuclear reaction rates in the Sun is reviewed.   This calculation is not good enough for two reasons.  First,  the  estimated accuracy of this caluclation is  not better then current accuracy of neutrino observations.  Second, the calculation is not rigorous, and its accuracy is strictly speaking unknown.  A better theory of reaction rates in the solar plasma is highly desirable, and we will argue that a more accurate calculation  should be possible.

Todd Haines


Double CHOOZ and SuperK


Chuck Horowitz

Indiana U.

Supernova neutrinos before oscillations

We discuss the physics and astrophysics that determine supernova neutrino radiations as groundwork for oscillation studies.  Interactions responsible for nu_e, anti-nu_e, nu_x (nu_mu, nu_tau), and anti-nu_x spectra will be discussed.  We emphasize the importance of measuring the nu_x spectrum and we discuss new nu_x detectors based on neutrino-nucleus elastic scattering.  We review r-process nucleosynthesis in neutrino driven winds and discuss its sensitivity to new neutrino physics.  Finally, we present a virial expansion of the equation of state of low density nuclear matter.  This allows us to determine, model independently, the composition and neutrino interactions of nuclear matter near the neutrino-sphere.  This should allow better predictions of neutrino spectra in the future.

Jim Kneller

North Carolina

Monte Carlo Neutrino Oscillations And The Temporal Evolution Of The Supernovae Neutrino Signal

We present a novel technique for calculating crossing probabilites based upon random sampling of a scattering matix. We apply the method to the case of a density profile from a 2D supernova simulation.

Alex Kusenko


Dark matter, baryogenesis, and the pulsar kicks from a keV sterile neutrino

Observational evidence for dark matter demands an explanation beyond the Standard Model. The minimal modification of the Standard Model that makes it consistent with cosmology is the addition of a sterile neutrino with a mass of a few keV. If such a particle exist, it could also explain the observed pulsar velocities and provide a viable scenario for baryogenesis. Future data from X-ray astronomy and detection of gravity waves may help confirm or rule out this explanation.

Cecilia Lunardini

Institute for Nuclear Theory and U. of Washington

Neutrino Oscillations and Non-Standard Neutrino-Matter Interactions

New physics at the TeV scale can manifest itself in the form of new, non-standard interactions (NSI) of neutrinos with matter.  Accelerator tests leave these interactions still poorly constrained, especially in the electron- and tau-neutrino sector.  I discuss the sensitivity of neutrino oscillations in matter to the NSI and show how current solar and atmospheric neutrino experiments improve with the respect to the accelerator bounds on the NSI.  For the specific case of atmospheric neutrinos, I give the results of a numerical analysis of the data and the analytics of the underlying physics. The results proceed from a full three neutrinos analysis and thus are qualitatively different from previous two-neutrino studies.

Gordon McGregor


Status of the MiniBooNE Experiment

The MiniBooNE experiment at Fermilab has been running since the summer of 2002. It will test the evidence for neutrino oscillations from the LSND experiment by searching for the appearance of electron neutrinos in a muon neutrino beam. The current status of the MiniBooNE experiment and the latest comparisons between
data and Monte Carlo will be presented.

Gail McLaughlin

North Carolina

Neutrinos and Nucleosynthesis from Supernova and GRBS

There is increasing evidence that long duration gamma ray bursts are associated with core collapse supernovae, and speculation that short duration gamma ray bursts are associated with neutron star mergers. In either scenario a rapidly accreting disk forms surrounding a black hole. The disk releases large numbers of neutrinos that influence the element synthesis in the disk outflow. We will discuss the neutrinos as well as the element synthesis.

Danny Marfatia

U. of Kansas

Solar mass-varying neutrino oscillations

We propose that the solar neutrino deficit may be due to oscillations of mass-varying neutrinos (MaVaNs). This scenario elucidates solar neutrino data beautifully while remaining comfortably compatible with atmospheric neutrino and K2K data and with reactor antineutrino data at short and long baselines (from CHOOZ and KamLAND). We find that the survival probability of solar MaVaNs is independent of how the suppression of neutrino mass caused by the acceleron-matter couplings varies with density. Measurements of MeV and lower energy solar neutrinos will provide a rigorous test of the idea.

Irina Mocioiu

Argonne/U. of Chicago


Heinrich Paes

University of Hawaii at Manoa

Neutrino oscillations and shortcuts in the extra dimension

Theories with large extra dimensions have provided new perspectives on a plethora of old problems in particle physics and cosmology. Interesting applications include the amelioration of the large hierarchy between the weak and the Planck scale, the generation of small neutrino masses and the prediction of quantum gravity effects at energy scales around a TeV. Also a non-inflationary solution to the cosmological horizon problem has been advocated, utilizing graviton shortcuts in the extra-dimensional bulk. The talk introduces a new consequence of extra dimensions, namely neutrino oscillations due to sterile neutrino shortcuts in the extra dimension. This scenario has the potential to abolish the contradiction of the LSND neutrino oscillation experiment with other short-baseline experiments and/or solar and atmospheric neutrino oscillation results. It also predicts interesting effects for future neutrino oscillation experiments,neutrinoless double beta decay, big-bang nucleosynthesis, supernova neutrinos and neutrino dark matter. Finally sterile neutrino shortcuts may be superior to graviton shortcuts in solving the horizon problem and the wormhole-like shortcuts may be used for superluminal and back-in-time communication.

Maxim Perelstein

Cornell U.

Light Sterile Neutrinos and Cosmology

Models with low-scale breaking of global symmetries in the neutrino sector provide an alternative to the seesaw mechanism for understanding why neutrinos are light. Such models can easily incorporate light sterile neutrinos required by the LSND experiment. Furthermore, the constraints on the sterile neutrino properties from nucleosynthesis and large scale structure can be removed due to the non-conventional cosmological evolution of neutrino masses and densities. I will present explicit, fully realistic supersymmetric models, and discuss the characteristic signatures predicted in the angular distributions of the cosmic microwave background.

Gilad Perez


Late neutrino masses: Mini Z' burst & Electroweak Leptogenesis

In the late neutrino masses framework neutrinos are light due to a low scale of symmetry breaking. We discuss two observational aspects related to this framework as follows: (i) We show that the interaction between relic supernova neutrinos (RSN) and the cosmic background ones, via exchange of light scalars, can result in a dramatic change of the supernova (SN) neutrinos flux. We show how observation of neutrinos from SN1987A constrains the related symmetry breaking scale. We also discuss how near future experiments may confirm/constrain the above models, either by detecting the ``accumulative resonance'' that diffuse RSN go through or via a large suppression of the flux of neutrinos from nearby SN bursts. (ii) Electroweak Baryogenesis, given a first order phase transition, does not work in the standard model because the quark Yukawas are hierarchical. On the other hand, the neutrino mass matrix is a not hierarchical which leads to large CP-violation in the reflection of heavy leptons by the expanding Higgs bubble wall, and can generate the baryon asymmetry of the universe. The mechanism predicts, O(TeV), vector-like leptons and
sizable mu -> e rates.

Keith Rielage

Center for Experimental Nuclear Physics and Astrophysics, U. of Washington

Results from the Sudbury Neutrino Observatory and New Directions in Solar Neutrino Experiments

The Sudbury Neutrino Observatory (SNO) has provided constraints on neutrino mixing parameters by using several methods of determining the solar neutrino flux via the neutral current reaction.  The first two methods (the D20 and Salt phases) have been completed and a summary of results will be presented.  The final phase utilizing an array of neutral current detectors was begun in 2004 and the expected improvement in the measurements will be discussed.  In addition, future solar neutrino experiments currently being developed will be examined along with their ability to test the current oscillation models.

Ray Sawyer


Neutrino clouds can do very strange things

When clouds of neutrinos have non-isotropic flavor-momentum distributions, the neutrino-neutrino forward interaction (in conjunction with the oscillation terms) can bring about very rapid exchanges of flavor between one region of momentum space to another. Two examples are discussed: In the first the exchanges are very fast indeed, with a rate on the order of (G_F)X(no. density). The results are robust with respect to making moderate changes in the oscillation and initial flavor assignment parameters, but perhaps require more complex angular distributions than one is likely to find in a physical system of interest. In the second example the rate is the geometric mean of the above fast rate and an ordinary oscillation rate. It requires some fine-tuning with respect to the initial value assignments, but the parameters that obtain just under the neutrinosphere in a supernova may be in the region of the instability.

Gary Steigman

Ohio State U.

Neutrinos, BBN, and CBR

Neutrinos, their mixing and interactions, play an important role in regulating physical processes in the early Universe. As a result, the early Universe offers a window on aspects of neutrino physics which are otherwise difficult to probe in terrestrial experiments. In this talk I will concentrate of the role(s) of neutrinos in Big Bang Nucleosynthesis (BBN) when the Universe was minutes old and, also, how their presence affects the spectrum of temperature fluctuations imprinted on the Cosmic Background Radiation (CBR) nearly 400 thousand years later. In particular, BBN and the CBR will be employed to probe any lepton asymmetry in the relic neutrinos and to explore whether the known, active neutrinos were fully populated in the early Universe.