10,311 research outputs found
Corrections to Tribimaximal Mixing from Nondegenerate Phases
We propose a seesaw scenario that possible corrections to the tribimaximal
pattern of lepton mixing are due to the small phase splitting of the
right-handed neutrino mass matrix. we show that the small deviations can be
expressed analytically in terms of two splitting parameters( and
) in the leading order. The solar mixing angle favors a
relatively smaller value compared to zero order value (), and the
Dirac type CP phase chooses a nearly maximal one. The two Majorana
type CP phases and turn out to be a nearly linear dependence.
Also a normal hierarchy neutrino mass spectrum is favored due to the stability
of perturbation calculations.Comment: 19 pages 6 figures, Accepted by Mod. Phy. Lett.
Neutrino Factories: Physics Potential
The physics potential of low-performance and high-performance neutrino
factories is briefly reviewed..Comment: Talk presented at NUFACT02, London, 1-6 July, 2002. 8 pages, 5
figure
Left-Right Asymmetry of Weak Interaction Mass of Polarized Fermions in Flight
The left-right polarization-dependent asymmetry of the weak interaction mass
is investigated. Based on the Standard Model, the calculation shows that the
weak interaction mass of left-handed polarized fermions is always greater than
that of right-handed polarized fermions in flight with the same velocity in any
inertial frame. The asymmetry of the weak interaction mass might be very
important to the investigation of neutrino mass and would have an important
significance for understanding the parity nonconservation in weak interactions.Comment: 8 pages, 2 figures, corrected calculatio
Hydrophobicity properties of graphite and reduced graphene oxide of the polysulfone (PSf) mixed matrix membrane
Hydrophobicity properties of graphite and reduced graphene oxide (rGO) (from exfoliated graphite/rGO) towards PSf polymer membrane characteristic and properties at different additives weight concentrations (1, 2, 3, 4 and 5 wt. %) were investigated. Both PSF/graphite and PSf/rGO membranes were characterized in term of hydrophobicity, surface bonding, surface roughness and porosity. FTIR peaks revealed that membrane with graphite and reduced graphene oxide nearly diminished their O-H bonding which was opposite to the graphene oxide peak that shows a strong O-H bonding as increased exfoliated times. These results were in line with the contact angle results that showed strong hydrophobicity of graphite and reduced graphene oxide membranes as increased these additives concentration. The effect of strong hydrophobicity in these membranes also has resulted in smoother surface roughness compared to pristine PSf membrane. Further investigation of the performance of water flux also proved that both above membranes have strong hydrophobic effect, with the lowest pure water flux rate (L/m2h) was given by PSf/rGO 3% membrane at 19.2437 L/m2h
Thermodynamics of interacting entropy-corrected holographic dark energy in a non-flat FRW universe
A so-called "entropy-corrected holographic dark energy" (ECHDE), was recently
proposed to explain the dark energy-dominated universe with the help of quantum
corrections to the entropy-area relation in the setup of loop quantum
cosmology. Using this new definition, we investigate its thermodynamical
features including entropy and energy conservation. We describe the
thermodynamical interpretation of the interaction between ECHDE and dark matter
in a non-flat universe. We obtain a relation between the interaction term of
the dark components and thermal fluctuation. Our study further generalizes the
earlier works [M.R. Setare and E.C. Vagenas, Phys. Lett. B 666 (2008) 111; B.
Wang et al., Phys. Lett. B 662 (2008) 1] in this direction.Comment: 14 pages, no figure, accepted by Int. J. Mod. Phys.
Leptogenesis via multiscalar coherent evolution with supersymmetric neutrino see-saw
A novel scenario of leptogenesis is investigated in the supersymmetric
neutrino see-saw model. The right-handed sneutrino and the field in the direction of the slepton and Higgs
doublets start together coherent evolution after the inflation with
right-handed neutrino mass smaller than the Hubble parameter of
inflation. Then, after some period the motion of and is
drastically changed by the cross coupling
from the and terms, and the significant
asymmetries of and are generated. The asymmetry is fixed later by the thermal effect as the lepton number
asymmetry for baryogenesis, while the asymmetry disappears
through the decays with almost the same rate but opposite final lepton numbers.Comment: 4pages, 1 figure; submitted to Physical Review D. The renormalization
group effects were include
A question of hierarchy: matter effects with atmospheric neutrinos and anti-neutrinos
It is by now established that neutrinos mix, have (different) non-zero
masses, and therefore oscillate. The oscillation parameters themselves,
however, are not all well-known. An open problem is that of the neutrino mass
hierarchy. We study the possibility of determining the neutrino mass hierarchy
with atmospheric neutrinos using an iron calorimeter detector capable of charge
identification such as the proposed MONOLITH and ICAL/INO detectors. We find
that such detectors are sensitive to the sign of the mass-squared difference,
\delta_{32} = m_3^2 - m_2^2, provided the as-yet unknown mixing angle between
the first and third generations, \theta_{13}, is greater than 6 degrees (\sin^2
2\theta_{13} > 0.04). A result with a significance greater than 90% CL requires
large exposures (more than 500 kton-years) as well as good energy and angular
resolution of the detected muons (better than 15%), especially for small
\theta_{13}. Hence obtaining definitive results with such a detector is
difficult, unless \theta_{13} turns out to be large. In contrast, such
detectors can establish a clear oscillation pattern in atmospheric neutrinos in
about 150 kton-years, therefore determining the absolute value of \delta_{32}
and \sin^2 2 \theta_{23} to within 10%.Comment: 36 pages revtex with 14 eps figures; new section on statistical
significance when detector resolution is include
Peningkatan Kemampuan Pemecahan Masalah Matematis Siswa dengan Menggunakan Model Pembelajaran Creative Problem Solving pada Materi Spldv di Kelas VIII SMP Negeri 2 Takengon
Kemampuan pemecahan masalah merupakan salah satu tujuan atau kompetensi yang akan dicapai dalam pelajaran matematika. Semua pemecahan masalah melibatkan beberapa informasi dan untuk mendapatkan penyelesaiannya digunakan informasi tersebut. Informasi-informasi ini pada umumnya merupakan konsep-konsep atau prinsip-prinsip dalam matematika salah satunya pada sistem persamaan linear dua variabel. karena akan memudahkan siswa untuk menghitung barang belanjaan di pasar dan juga memudahkan siswa nantinya apabila akan membuat sebuah Perusahan. Selain siswa kurang bisa dalam menyelesaikan soal sistem pesamaan linear dua variabel siswa juga masih kurang terampil dalam menjawab soal pemecahan masalah. Untuk itu peneliti menggukan model pembelajaran Creative Problem Solving (CPS) dalam pemecahan masalah matematis siswa. Penelitian ini bertujuan untuk mengetahui peningkatan dan perbedaan hasil belajar menggunakan model Creative Problem Solving (CPS) pada siswa kelas VIII SMP Negeri 2 Takengon. Penelitian ini menggunakan pendekatan kuantitatif dengan jenis penelitiannya yaitu quasi ekperimen, karena penelitian ini ingin mengetahui perbedaan dari kelas eksperimen dan kontrol serta ingin melihat peningkatan pada kelas eksperimen yang diberi perlakuan model pembelajaran (CPS). Penelitian yaitu dengan nilai rata-rata pada kelas yang kontrol yaitu 42,9 dan nilai rata-rata pada kelas eksperimen yaitu 53,4, yang dimana kelas tersebut berdistribusi normal. Dengan nilai uji hipotesis thitung ttabel dimana 12,53 2,02 dengan demikian Ha diterima, sehingga terdapat perbedaan rerata kemampuan pemecahan masalah siswa. Dan hasil pengujian gain ternormalisasi diperoleh untuk kriteria gain ternormalisasi terendah 4 siswa (20%) dan dengan kriteria sedang diperoleh 16 siswa (80%), Sehingga dapat disimpulkan terdapat peningkatan kemampuan masalah siswa pada kelas VIII SMP Negeri 2 Takengon dengan model pembelajaran Creative Problem Solving (CPS)
Neutrino oscillation and expected event rate of supernova neutrinos in adiabatic explosion model
We study how the influence of the shock wave appears in neutrino oscillations
and the neutrino spectrum using density profile of adiabatic explosion model of
a core-collapse supernova which is calculated in an implicit Lagrangian code
for general relativistic spherical hydrodynamics. We calculate expected event
rates of neutrino detection at SK and SNO for various theta_{13} values and
both normal and inverted hierarchies. The predicted event rates of bar{nu}_e
and nu_e depend on the mixing angle theta_{13} for the inverted and normal
hierarchies, respectively, and the influence of the shock appears for about 2 -
8 s when sin^2 2 theta_{13} is larger than 10^{-3}. These neutrino signals for
the shock propagation is decreased by < 30 % for bar{nu}_e in inverted (SK) or
by < 15 % for nu_e in normal hierarchy (SNO) compared with the case without
shock. The obtained ratio of the total event for high-energy neutrinos (20 MeV
< E_{nu} < 60 MeV) to low-energy neutrinos (5 MeV < E_{nu} < 20 MeV) is
consistent with the previous studies in schematic semi-analytic or other
hydrodynamic models of the shock propagation. The time dependence of the
calculated ratio of the event rates of high-energy to low-energy neutrinos is a
very useful observable which is sensitive to theta_{13} and hierarchies.
Namely, time-dependent ratio shows clearer signal of the shock propagation that
exhibits remarkable decrease by at most factor \sim 2 for bar{nu}_e in inverted
(SK), whereas it exhibits smaller change by \sim 10 % for nu_e in normal
hierarchy (SNO). Observing time-dependent high-energy to low-energy ratio of
the neutrino events thus would provide a piece of very useful information to
constrain theta_{13} and mass hierarchy, and eventually help understanding the
propagation how the shock wave propagates inside the star.Comment: 19 pages, 9 figures, accepted for publication in Physical Review
Neutrino oscillation probabilities: Sensitivity to parameters
We study in detail the sensitivity of neutrino oscillation probabilities to
the fundamental neutrino parameters and their possible determination through
experiments. The first part of the paper is devoted to the broad theme of
isolating regions in the neutrino (and anti-neutrino) energy and propagation
length that are sensitive to the oscillation parameters. Such a study is
relevant to neutrinos both from the Earth's atmosphere or from a neutrino
factory. For completeness we discuss the sensitivity, however small, to the
parameters involved in a three-generation framework, and to the Earth matter
density profile. We then study processes relevant to atmospheric neutrinos
which are sensitive to and allow precision measurements of the mixing angle
theta_23 and mass-squared difference delta_32 apart from the mixing angle
theta_13. Crucial to this analysis is charge identification; detectors having
this capability can isolate these matter effects. In particular, we address the
issue of using matter effects to determine whether the mixing angle theta_23 is
maximal, and, if not, to explore how well its octant can be determined. When
realistic detector resolutions are included, we find that deviations of about
15% (20%) from a maximal value of sin^2 theta_23=1/2 can be measured at 95%
(99%) CL provided theta_13 is non-zero, sin^2 theta_13 >= 0.015, and the
neutrino mass ordering is normal, with fairly large exposures of 1000
kton-years.Comment: 37 pages Latex file, 30 eps figure files; minor typos fixe
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