642 research outputs found
Signatures of supernova neutrino oscillations in the Earth mantle and core
The Earth matter effects on supernova (SN) neutrinos can be identified at a
single detector through peaks in the Fourier transform of their ``inverse
energy'' spectrum. The positions of these peaks are independent of the SN
models and therefore the peaks can be used as a robust signature of the Earth
matter effects, which in turn can distinguish between different neutrino mixing
scenarios. Whereas only one genuine peak is observable when the neutrinos
traverse only the Earth mantle, traversing also the core gives rise to multiple
peaks. We calculate the strengths and positions of these peaks analytically and
explore their features at a large scintillation detector as well as at a
megaton water Cherenkov detector through Monte Carlo simulations. We propose a
simple algorithm to identify the peaks in the actual data and quantify the
chances of a peak identification as a function of the location of the SN in the
sky.Comment: 17 pages, 9 figure
Corrections to Tri-bimaximal Neutrino Mixing: Renormalization and Planck Scale Effects
We study corrections to tri-bimaximal (TBM) neutrino mixing from
renormalization group (RG) running and from Planck scale effects. We show that
while the RG effects are negligible in the standard model (SM), for
quasi-degenerate neutrinos and large in the minimal supersymmetric
standard model (MSSM) all three mixing angles may change significantly. In both
these cases, the direction of the modification of is fixed, while
that of is determined by the neutrino mass ordering. The Planck
scale effects can also change up to a few degrees in either
direction for quasi-degenerate neutrinos. These effects may dominate over the
RG effects in the SM, and in the MSSM with small . The usual
constraints on neutrino masses, Majorana phases or stemming from
RG running arguments can then be relaxed. We quantify the extent of Planck
effects on the mixing angles in terms of "mismatch phases" which break the
symmetries leading to TBM. In particular, we show that when the mismatch phases
vanish, the mixing angles are not affected in spite of the Planck scale
contribution. Similar statements may be made for - symmetric mass
matrices.Comment: 21 pages, 3 eps figures. Comments added, to appear in PR
Relative ability of ovine follicle stimulating hormone and its β-subunit to generate antibodies having bioneutralization potential in nonhuman primates
The relative ability of ovine follicle stimulating hormone and its β-subunit, two potential candidates for male contraceptive vaccine, to generate antibodies in monkeys capable of bioneutralizing follicle stimulating hormone was assessed usingin vitro model systems. Antiserum against native ovine follicle stimulating hormone was found to be highly specific to the intact form with no cross-reactivity with either of the two subunits while the antiserum against β-subunit of follicle stimulating hormone could bind to the β-subunit in its free form as well as when it is combined with α-subunit to form the intact hormone. Both antisera could block the binding of the hormone to the receptor if the hormone was preincubated with the antibody. However, the follicle stimulating hormone β-antisera could only inhibit the binding of the hormone partially (33% inhibition) if the antibody and receptor were mixed prior to the addition of the hormone, while antisera to the native follicle stimulating hormone could block the binding completely (100% inhibition) in the same experiment. Similarly antisera to the native follicle stimulating hormone was significantly effective in blocking (100%) response to follicle stimulating hormone but not the β-subunit antisera (0%) as checked using anin vitro granulosa cell system. Thus the probability of obtaining antibodies of greater bioneutralization potential is much higher if intact hormone is used as an antigen rather than its β-subunit as a vaccine
Ability of human chorionic gonadotropin β-subunit to inhibit the steroidogenic response to lutropin
Ability of the β-subunit of human chorionic gonadotropin to inhibit the response to lutropin (luteinizing hormone, LH) was tested in the immature rat ovarian system and pregnant-mare-serum-gonadotropin-primed rat ovarian system with progesterone production being used as the response. Human chorionic gonadotropin β-subunit was found to inhibit human and ovine lutropin-stimulated progesterone production. At a constant dose of lutropin, inhibition was dependent on the concentration of β-subunit. When concentration of the β-subunit was kept constant at 5.0 μg/ml and the concentration of lutropin was varied, the inhibition was maximum at the saturating concentration of the native hormone. The α-subunit of the human chorionic gonadotropin did not inhibit the response to lutropin. The lutropin/β-subunit ratio required to produce an inhibition of response was much lower than that required to bring about an observable inhibition of binding
Supernova neutrino oscillations: what do we understand?
We summarize our current understanding of the neutrino flavor conversions
inside a core collapse supernova, clarifying the important role played by the
"collective effects" in determining flavor conversion probabilities. The
potentially observable and spectra may help us identify
the neutrino mixing scenario, distinguish between primary flux models, and
learn more about the supernova explosion.Comment: 6 pages, 1 eps figure, jpconf.cls used. Talk given at TAUP 2009,
Rome, July 200
Observables in the Decays of B to Two Vector Mesons
In general there are nine observables in the decay of a B meson to two vector
mesons defined in terms of polarization correlations of these mesons. Only six
of these can be detected via the subsequent decay angular distributions because
of parity conservation in those decays. The remaining three require the
measurement of the spin polarization of one of the decay products.Comment: 12 pages, no figur
Physics potential of future supernova neutrino observations
We point out possible features of neutrino spectra from a future galactic
core collapse supernova that will enhance our understanding of neutrino mixing
as well as supernova astrophysics. We describe the neutrino flavor conversions
inside the star, emphasizing the role of "collective effects" that has been
appreciated and understood only very recently. These collective effects change
the traditional predictions of flavor conversion substantially, and enable the
identification of neutrino mixing scenarios through signatures like Earth
matter effects.Comment: 8 pages, uses jpconf.cls. Talk given at Neutrino 2008, Christchurch,
NZ. Some entries in Table 2 have been correcte
Weak phase information from the color suppressed B_d^0 -> D^{*0} K^{*0} modes
The decay channels are investigated for extracting
weak phase information. These channels are described by color-suppressed
tree diagrams only and are free from penguin contributions. The branching
ratios for these channels are found to be
which can be measured at the currently running factories. The method
presented here may be well-suited to determine the phase .Comment: 11 pages, revised extensively, version to appear in Phys. Rev.
An immunological approach to study gonadotropin action at the cellular and molecular level
This article does not have an abstract
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