1,568 research outputs found
Possible Supersymmetric Effects on Angular Distributions in Decays
We investigate the angular distributions of the rare B decay, , in general supersymmetric extensions of the standard
model. We consider the new physics contributions from the operators
in small invariant mass region of lepton pair. We show that the
azimuthal angle distribution of the decay can tell us the new physics effects
clearly from the behavior of the distribution, even if new physics does not
change the decay rate substantially from the standard model prediction
Flavor Democracy in Standard Models at High Energies
It is possible that the standard model (SM) is replaced around some
transition energy \E_{tr} by a new, possibly Higgsless, ``flavor gauge
theory'' such that the Yukawa (running) parameters of SM at E \sim \E_{tr}
show up an (approximate) flavor democracy (FD). We investigate the latter
possibility by studying the renormalization group equations for the Yukawa
couplings of SM with one and two Higgs doublets, by evolving them from given
physical values at low energies () to \E_{tr} ( \sim
\E_{pole}) and comparing the resulting fermion masses and CKM matrix elements
at E \simeq \E_{tr} for various and ratios of vacuum
expectation values. We find that the minimal SM and the closely related SM with
two Higgs doublets (type I) show increasing deviation from FD when energy is
increased, but that SM with two Higgs doublets (type II) clearly tends to FD
with increasing energy - in both the quark and the leptonic sector (q-q and l-l
FD). Furthermore, we find within the type II model that, for \E_{pole} \ll
\E_{Planck}, can be less than in most cases of chosen
. Under the assumption that also the corresponding Yukawa couplings in
the quark and the leptonic sector at E \simeq \E_{tr} are equal (l-q FD), we
derive estimates of bounds on masses of top quark and tau-neutrino, which are
compatible with experimental bounds.Comment: 23 pages (7 Figs. available on request), standard LATEX, preprint
DO-TH 93-08, SNUTP 93-12, YUMS 93-0
CP Violation from Dimensional Reduction: Examples in 4+1 Dimensions
We provide simple examples of the generation of complex mass terms and hence
CP violation through dimensional reduction.Comment: 6 pages, typos corrected, 1 reference adde
Higgs-mediated leptonic decays of B_s and B_d mesons as probes of supersymmetry
If tan(beta) is large, down-type quark mass matrices and Yukawa couplings
cannot be simultaneously diagonalized, and flavour violating couplings of the
neutral Higgs bosons are induced at the 1-loop level. These couplings lead to
Higgs-mediated contributions to the decays B_s -> mu+ mu- and B_d -> tau+ tau-,
at a level that might be of interest for the current Tevatron run, or possibly,
at B-factories. We evaluate the branching ratios for these decays within the
framework of minimal gravity-, gauge- and anomaly-mediated SUSY breaking
models, and also in SU(5) supergravity models with non-universal gaugino mass
parameters at the GUT scale. We find that the contribution from gluino loops,
which seems to have been left out in recent phenomenological analyses, is
significant. We explore how the branching fraction varies in these models,
emphasizing parameter regions consistent with other observations.Comment: Revised to accommodate minor changes in original text and update
reference
Breast cancer genetic risk profile is differentially associated with interval and screen-detected breast cancers
Background: Polygenic risk profiles computed from multiple common susceptibility alleles for breast
cancer have been shown to identify women at different levels of breast cancer risk. We
evaluated whether this genetic risk stratification can also be applied to discriminate between
screen-detected and interval cancers, which are usually associated with
clinicopathological and survival differences.
Patients and methods: A 77-SNP polygenic risk score (PRS) was constructed for breast cancer overall and by
estrogen-receptor (ER) status. PRS was inspected as a continuous (per standard deviation
increment) variable in a case-only design. Modification of the PRS by mammographic density
was evaluated by fitting an additional interaction term.
Results: PRS weighted by breast cancer overall estimates was found to be differentially associated
with 1,865 screen-detected and 782 interval cancers in the LIBRO-1 study (age-adjusted
ORperSD [95% confidence interval]=0.91 [0.83-0.99], p=0.023). The association was found to
be more significant for PRS weighted by ER-positive breast cancer estimates (ORperSD=0.90
[0.82-0.98], p=0.011). This result was corroborated by two independent studies (combined
ORperSD=0.87 [0.76-1.00], p=0.058) with no evidence of heterogeneity. When enriched for
âtrueâ interval cancers among nondense breasts, the difference in the association with PRS in
screen-detected and interval cancers became more pronounced (ORperSD=0.74 [0.62-0.89],
p=0.001), with a significant interaction effect between PRS and mammographic density
(pinteraction=0.017).
Conclusion: To our knowledge, this is the first report looking into the genetic differences between screendetected
and interval cancers. It is an affirmation that the two types of breast cancer may have
unique underlying biology.Swedish Research CouncilSwedish Cancer SocietyStockholm County CouncilBreast Cancer Theme Centre Consortium (BRECT)Accepte
Validation of DPOAE screening conducted by village health workers in a rural community with real-time click evoked tele-auditory brainstem response
OBJECTIVE : This study assessed the validity of DPOAE screening conducted by village health workers (VHWs) in a rural community. Real-time click evoked tele-auditory brainstem response (tele-ABR) was used as the gold standard to establish validity. DESIGN : A cross-sectional design was utilised to compare the results of screening by VHWs to those obtained via tele-ABR. STUDY SAMPLES : One hundred and nineteen subjects (0 to 5âyears) were selected randomly from a sample of 2880 infants and young children who received DPOAE screening by VHWs. Method: Real time tele-ABR was conducted by using satellite or broadband internet connectivity at the village. An audiologist located at the tertiary care hospital conducted tele-ABR testing through a remote computing paradigm. Tele-ABR was recorded using standard recording parameters recommended for infants and young children. Wave morphology, repeatability and peak latency data were used for ABR analysis. RESULTS : Tele-ABR and DPOAE findings were compared for 197 ears. The sensitivity of DPOAE screening conducted by the VHW was 75%, and specificity was 91%. The negative and positive predictive values were 98.8% and 27.2%, respectively. CONCLUSIONS : The validity of DPOAE screening conducted by trained VHW was acceptable. This study supports the engagement of grass-root workers in community-based hearing health care provision.Indian Council of Medical Research (No.5/8/10-4(Oto)10-NCD-I).http://www.tandfonline.com/loi/iija20hj2019Speech-Language Pathology and Audiolog
Model Building with Gauge-Yukawa Unification
In supersymmetric theories with extra dimensions, the Higgs and matter fields
can be part of the gauge multiplet, so that the Yukawa interactions can arise
from the gauge interactions. This leads to the possibility of gauge-Yukawa
coupling unification, g_i=y_f, in the effective four dimensional theory after
the initial gauge symmetry and the supersymmetry are broken upon orbifold
compactification. We consider gauge-Yukawa unified models based on a variety of
four dimensional symmetries, including SO(10), SU(5), Pati-Salam symmetry,
trinification, and the Standard Model. Only in the case of Pati-Salam and the
Standard Model symmetry, we do obtain gauge-Yukawa unification. Partial
gauge-Yukawa unification is also briefly discussed.Comment: 23 page
Signals of neutralinos and charginos from gauge boson fusion at the CERN Large Hadron Collider
We point out that interesting signals of the non-strongly interacting sector
of the supersymmetric standard model arise from the production of charginos and
neutralinos via vector boson fusion (VBF) at the Large Hadron Collider (LHC).
In particular, if R-parity is violated, the hadronically quiet signals of
charginos and neutralinos through direct production get considerably
suppressed. We show that in such cases, the VBF channel can be useful in
identifying this sector through clean and background-free final states.Comment: 10 pages Latex, 8 figures, minor changes in text and few references
added, to be published in Phys. Rev.
Like Sign Dilepton Signature for R-Parity Violating SUSY Search at the Tevatron Collider
The like sign dileptons provide the most promising signature for
superparticle search in a large category of -parity violating SUSY models.
We estimate the like sign dilepton signals at the Tevatron collider, predicted
by these models, over a wide region of the MSSM parameter space. One expects an
unambiguous signal upto a gluino mass of GeV ( GeV) with
the present (proposed) accumulated luminosity of .Comment: 12 page LaTeX file; 5 figures available upon request from the autho
GeV to TeV astrophysical tau neutrinos
Neutrinos with energy greater than GeV are copiously produced in the p(A,p)
interactions occurring in several astrophysical sites such as (i) the earth
atmosphere, (ii) our galactic plane as well as in (iii) the galaxy clusters. A
comparison of the tau and mu neutrino flux in the presence of neutrino
oscillations from these three representative astrophysical sites is presented.
It is pointed out that the non-atmospheric tau neutrino flux starts dominating
over the downward going atmospheric tau neutrino flux for neutrino energy E as
low as 10 GeV. This energy value is much lower than the energy value, E \geq
5\times 10^4 GeV, estimated for the dominance of the non-atmospheric mu
neutrino flux, in the presence of neutrino oscillations. Future prospects for
possible observations of non-atmospheric tau neutrino flux are briefly
mentioned.Comment: 17 pages, 5 figures (to appear in PLB
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