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

Testing Times for Supersymmetry: Looking Under the Lamp Post

We make a critical study of two highly-constrained models of supersymmetry --- the constrained minimal supersymmetric standard model (cMSSM), and the non-universal Higgs mass model (NUHM) --- in the light of the 125-126 GeV Higgs boson, the first observation of $B_s \to \mu\mu$ at the LHCb, and the updated $B \to \tau \nu$ branching ratio at BELLE. It turns out that these models are still allowed by the experimental data, even if we demand that there be a light stop with mass less than 1.5 TeV. The only significant effects of all these constraints are to push the mass of the light stop above $\sim 500$ GeV, and to prefer the universal trilinear coupling $A_0$ to be large and negative. We calculate the Higgs boson branching ratios to $WW, ZZ, \tau\tau$ and $\gamma\gamma$ in these models and show that improved experimental limits on these could put them to the most stringent experimental tests yet.Comment: Updated version consistent with recent data, a few references adde

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 $\nu_e$ and $\bar{\nu}_e$ 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

Neutrino oscillations in low density medium

For the case of small matter effects: $V \ll \Delta m^2/2E$, where $V$ is the matter potential, we develop the perturbation theory using $\epsilon \equiv 2VE/\Delta m^2$ as the expansion parameter. We derive simple and physically transparent formulas for the oscillation probabilities in the lowest order in $\epsilon$ which are valid for arbitrary density profile. The formulas can be applied for propagation of the solar and supernova neutrinos in matter of the Earth, substantially simplifying numerical calculations. Using these formulas we study sensitivity of the oscillation effects to structures of the density profile situated at different distances from the detector $d$. We show that for the mass-to-flavor state transitions, {\it e.g.}, $\nu_2 \to \nu_e$, the sensitivity is suppressed for remote structures: $d > l_{\nu} E/\Delta E$, where $l_{\nu}$ is the oscillation length and $\Delta E/E$ is the energy resolution of detector.Comment: discussion simplified, clarifications adde

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

Nonleptonic two-body charmless B decays involving a tensor meson in ISGW2 model

Nonleptonic charmless B decays into a pseudoscalar (P) or a vector (V) meson accompanying a tensor (T) meson are re-analyzed. We scrutinize the hadronic uncertainties and ambiguities of the form factors which appear in the literature. The Isgur-Scora-Grinstein-Wise updated model (ISGW2) is adopted to evaluate the relevant hadronic matrix elements. We calculate the branching ratios and CP asymmetries for various $B\to P(V)T$ decay processes. With the ISGW2 model, the branching ratios are enhanced by about an order of magnitude compared to the previous estimates. We show that the ratios \calB(B\to VT)/\calB(B\to PT) for some strangeness-changing processes are very sensitive to the CKM angle $\gamma$ ($\phi_3$).Comment: 23 pages, REVTEX; minor clarifications included; to appear in Phys. Rev.

Weak Phase γ\gamma From Ratio of B→KπB \to K \pi Rates

The ratio of partial decay rates for charged and neutral $B$ mesons to $K \pi$ final states provides information on the weak phase $\gamma \equiv {\rm Arg} (V_{ub}^*)$ when augmented with information on the CP-violating asymmetry in the $K^\pm \pi^\mp$ mode. The requirements for a useful determination of $\gamma$ are examined in the light of present information about the decays $B^0 \to K^+ \pi^-$, $B^+ \to K^0 \pi^+$, and the corresponding charge-conjugate modes. The effects of electroweak penguins and rescattering corrections are noted, and proposals are made for estimating and measuring their importance.Comment: 16 pages, latex, 3 figures, revised version sent to Phys. Rev.

Tree FCNC and non-unitarity of CKM matrix

We discuss possible signatures of the tree level FCNC, which results from the non-unitarity of CKM matrix. We first define the unitaity step-by-step, and possible test of the non-unitaity through the 4-value-KM parametrization. We, then, show how the phase angle of the unitary triangle would change in case of the vector-like down quark model. As another example of tree FCNC, we investigate the leptophobic $Z'$ model and its application to the recent $B_s$ mixing measurements.Comment: Talk given at Neutrino Masses and Mixings 2006 (NMM2006), Shizuoka, Japan (December 2006

Like-sign dimuon charge asymmetry in Randall-Sundurm model

We confirm that in order to account for the recent D\O\ result of large like-sign dimuon charge asymmetry, a considerable large new physics effect in $\Gamma_{12}^s$ is required in addition to a large CP violating phase in $B_s -\bar{B}_s$ mixing. In the Randall-Sundrum model of warped geometry, where the fermion fields reside in the bulk, new sources of flavor and CP violation are obtained. We analyze the like-sign dimuon asymmetry in this class of model, as an example of the desired new physics. We show that the wrong charge asymmetry, $a_{sl}^s$, which is related to the dimuon asymmetry, is significantly altered compared to the Standard Model value. However, experimental limits from $\Delta M_s$, $\Delta\Gamma_s$ as well as $K$ mixing and electroweak corrections constrain it to be greater than a $\sigma$ away from its experimental average value. This model cannot fully account for the D\O\ anomaly due to its inability to generate sufficient new contribution to the width difference $\Gamma^s_{12}$, even though the model can generate large contribution to the mass difference $M^s_{12}$.Comment: 20 pages, 9 figures, discussions and references added, accepted for publication in Physical Review

FORMULATION DEVELOPMENT AND STATISTICAL OPTIMIZATION OF A BILAYER TABLET OF BOSENTAN MONOHYDRATE AND SILDENAFIL CITRATE IN MANAGEMENT OF PULMONARY ARTERIAL HYPERTENSION

Objective: The current study aims at fabrication of an oral bilayer matrix tablet of bosentan monohydrate and sildenafil citrate; the optimisation of their in vitro release and characterization, thereby reducing the side effects associated with bosentan, reducing dosing frequency and increasing patient compliance in the management of pulmonary arterial hypertension. Methods: Methocel K4M Premium DC2, a directly compressible HPMC grade was used as the sustained release polymer. Pregelatinised starch is used as a diluent and release modifier and sodium lauryl sulphate (SLS) as a solubiliser. The blends of both layers were prepared, evaluated for precompression characteristics and compressed by direct compression. The compressed bilayer tablets were evaluated for their hardness, weight variation, friability, content uniformity and swelling index. The principle objective was to assess the influence of the above variables on in vitro drug release of Bosentan using a 23 factorial design. Responses are measured as drug release at 2h (Q2), 6h (Q6) and 10h (Q10). Results: HPMC and pregelatinized starch form a synergistic gel thereby controlling drug release of bosentan for a 12 hour period. Batch BS09 consisting of 40 mg HPMC, 30 mg Pregeletinized starch and 5 mg SLS showed adequate controlled release for a 12 h period. Immediate release layer of sildenafil citrate showed optimum drug release of 102.96% within 30 min. Conclusion: Bilayer tablet of bosentan and sildenafil is an ideal combination for patients failing monotherapy in pulmonary arterial hypertension