1,568 research outputs found

    Possible Supersymmetric Effects on Angular Distributions in B→K∗(→Kπ)ℓ+ℓ−B \to K^* (\to K \pi) \ell^+ \ell^- Decays

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    We investigate the angular distributions of the rare B decay, B→K∗(→Kπ)ℓ+ℓ−B \to K^* (\to K \pi) \ell^+ \ell^-, in general supersymmetric extensions of the standard model. We consider the new physics contributions from the operators O7,8,9,10O_{7,8,9,10} 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

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    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 (E≃1GeVE \simeq 1 GeV) to \E_{tr} ( \sim \E_{pole}) and comparing the resulting fermion masses and CKM matrix elements at E \simeq \E_{tr} for various mtphym_t^{phy} and ratios vu/vdv_u/v_d 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}, mtphym_t^{phy} can be less than 200GeV200 GeV in most cases of chosen vu/vdv_u/v_d. 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

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    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

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    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

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    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 “true” 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

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    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 5 years) 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

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    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

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    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

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    The like sign dileptons provide the most promising signature for superparticle search in a large category of RR-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 200−300200 - 300 GeV (≄500\geq 500 GeV) with the present (proposed) accumulated luminosity of ∌0.1 (1) fb−1\sim 0.1~(1)~{\rm fb}^{-1}.Comment: 12 page LaTeX file; 5 figures available upon request from the autho

    GeV to TeV astrophysical tau neutrinos

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    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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