Results 1  10
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206
Electroweak Corrections to the Charm Quark Contribution to K
 π + ν¯ν, Phys. Rev. D78 (2008) 034006, [arXiv:0805.4119
"... We compute the leadinglog QED, the nexttoleadinglog QEDQCD, and the electroweak corrections to the charm quark contribution relevant for the rare decay K + → π + ν¯ν. The corresponding parameter Pc(X) is increased by up to 2% with respect to the pure QCD estimate to Pc(X) = 0.372 ± 0.015 for m ..."
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Cited by 23 (2 self)
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We compute the leadinglog QED, the nexttoleadinglog QEDQCD, and the electroweak corrections to the charm quark contribution relevant for the rare decay K + → π + ν¯ν. The corresponding parameter Pc(X) is increased by up to 2% with respect to the pure QCD estimate to Pc(X) = 0.372 ± 0.015 for mc(mc) = (1.286±0.013)GeV, αs(MZ) = 0.1176±0.0020 and Vus  = 0.2255. For the branching ratio we find B(K + → π + ν¯ν) = (8.5 ± 0.7) × 10 −11, where the quoted uncertainty is dominated by the CKM elements. 1
Baryons from instantons in holographic QCD
 Rev. D
, 2007
"... We consider aspects of dynamical baryons in a holographic dual of QCD that is formulated on the basis of a D4/D8brane configuration. We construct a soliton solution carrying a unit baryon number and show that it is obtained as an instanton solution of fourdimensional YangMills theory with fixed s ..."
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Cited by 15 (0 self)
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We consider aspects of dynamical baryons in a holographic dual of QCD that is formulated on the basis of a D4/D8brane configuration. We construct a soliton solution carrying a unit baryon number and show that it is obtained as an instanton solution of fourdimensional YangMills theory with fixed size. The ChernSimons term on the flavor D8branes plays a crucial role of protecting the instanton from collapsing to zero size. By quantizing the collective coordinates of the soliton, we derive the baryon spectra. Negativeparity baryons as well as baryons with higher spins and isospins can be obtained in a simple manner.
Panglossian Prospects for Detecting Neutralino
 Dark Matter in Light of Natural Priors, arXiv:0806.1923 [hepph
"... Abstract: In most global fits of the constrained minimal supersymmetric model (CMSSM) to indirect data, the a priori likelihoods of any two points in tanβ are treated as equal, and the more fundamental µ and B Higgs potential parameters are fixed by potential minimization conditions. We find that, i ..."
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Cited by 11 (2 self)
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Abstract: In most global fits of the constrained minimal supersymmetric model (CMSSM) to indirect data, the a priori likelihoods of any two points in tanβ are treated as equal, and the more fundamental µ and B Higgs potential parameters are fixed by potential minimization conditions. We find that, if instead a flat prior measure on µ and B is placed, a strong preference exists for the focus point region from fits to particle physics and cosmological data. In particular, we find that the lightest neutralino is strongly favored to be a mixed binohiggsino ( ∼ 10 % higgsino). Such mixed neutralinos have large elastic scattering cross sections with nuclei, leading to extremely promising prospects for both underground direct detection experiments and neutrino telescopes. In particular, the majority of the posterior probability distribution falls within parameter space within an order of magnitude of current direct detection constraints. Furthermore, neutralino annihilations in the sun are predicted to generate thousands of neutrino induced muon events per years at IceCube. Thus, assuming the framework of the CMSSM, we are likely to be living in a world with very nearly the best of all possible prospects for the direct and indirect detection of
Bayesian Selection of sign µ within mSUGRA in Global Fits Including WMAP5 Results
, 807
"... Abstract: We study the properties of the constrained minimal supersymmetric standard model (mSUGRA) by performing fits to updated indirect data, including the relic density of dark matter inferred from WMAP5. In order to find the extent to which µ < 0 is disfavoured compared to µ> 0, we compar ..."
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Cited by 7 (1 self)
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Abstract: We study the properties of the constrained minimal supersymmetric standard model (mSUGRA) by performing fits to updated indirect data, including the relic density of dark matter inferred from WMAP5. In order to find the extent to which µ < 0 is disfavoured compared to µ> 0, we compare the Bayesian evidence values for these models, which we obtain straightforwardly and with good precision from the recently developed multi–modal nested sampling (‘MultiNest’) technique. We find weak to moderate evidence for the µ> 0 branch of mSUGRA over µ < 0 and estimate the ratio of probabilities to be P(µ> 0)/P(µ < 0) = 6−61 depending on the prior measure and range used. There is thus positive (but not overwhelming) evidence that µ> 0 in mSUGRA. The MultiNest technique also delivers probability distributions of parameters and other relevant quantities such as superpartner masses. We explore the dependence of our results on the choice of the prior measure used. We also use the Bayesian evidence to quantify the consistency between the mSUGRA parameter inferences coming from the constraints that have the
Study of FCNC mediated rare Bs decays in a single universal extra dimension scenario, Phys. Rev. D75
, 2007
"... We study the rare semileptonic and radiative leptonic Bs decays in the universal extra dimension model. In this scenario, with a single extra dimension, there exists only one new parameter beyond those of the standard model, which is the inverse of the compactification radius R. We find that with th ..."
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We study the rare semileptonic and radiative leptonic Bs decays in the universal extra dimension model. In this scenario, with a single extra dimension, there exists only one new parameter beyond those of the standard model, which is the inverse of the compactification radius R. We find that with the additional contributions due to the KK modes the branching ratios of the rare Bs decays are enhanced from their corresponding standard model values and the zero point of the forward backward asymmetries Although the standard model (SM) of electroweak interaction is very successful in explaining the observed data so far, but still it is believed that there must exist some new physics beyond the SM, whose true nature is not yet wellknown. Therefore, intensive search for physics beyond the SM is now being performed in various areas of particle physics. In
Neutralino Dark Matter from Indirect Detection Revisited
, 807
"... Abstract: We revisit indirect detection possibilities for neutralino dark matter, emphasizing the complementary roles of different approaches. While thermally produced dark matter often requires large astrophysical ”boost factors ” to observe antimatter signals, the physically motivated alternative ..."
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Abstract: We revisit indirect detection possibilities for neutralino dark matter, emphasizing the complementary roles of different approaches. While thermally produced dark matter often requires large astrophysical ”boost factors ” to observe antimatter signals, the physically motivated alternative of nonthermal dark matter can naturally provide interesting signals, for example from light wino or higgsino dark matter. After a brief review of cosmic ray propagation, we discuss signals for positrons, antiprotons, synchrotron radiation and gamma rays from wino annihilation in the galactic halo, and examine their phenomenology. For pure wino dark
Charm Physics Opportunities at a Super Flavor Factory, arXiv:0711.3044 [hepex
"... The primary physics goals of a high luminosity e + e − flavor factory are discussed, including the possibilities to perform detailed studies of the CKM mechanism of quark mixing, and constrain virtual Higgs and nonstandard model particle contributions to the dynamics of rare Bu,d,s decays. The large ..."
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The primary physics goals of a high luminosity e + e − flavor factory are discussed, including the possibilities to perform detailed studies of the CKM mechanism of quark mixing, and constrain virtual Higgs and nonstandard model particle contributions to the dynamics of rare Bu,d,s decays. The large samples of D mesons and tau leptons produced at a flavor factory will result in improved sensitivities to rare D processes mixing, CP violation and rare decays and lepton flavor violation searches, respectively. Recent developments in accelerator physics have demonstrated the feasibility to build an accelerator that can achieve luminosities of O(10 3 6) cm −2 s −1 at √ s = 10 GeV. The capablity to run at √ s = 3.770 GeV with luminosity of 10 35 cm −2 s −1 is included in the initial design. This report emphasizes the charm physics that can be probed at a Super Flavor Factory. These proceedings aim to present a brief overview of the SuperB effort with a special emphasis on the charm physics program of such a facility. In the interest of completeness (and time) some passages from the SuperB Conceptual Design Report[1] are reproduced here. 1.
GUTs and Exceptional Branes in Ftheory  II: Experimental Predictions, arXiv:0806.0102 [hepth]; GUTs and Exceptional Branes in Ftheory
 N = 2 Supersymmetric Black Attractors in Six and Seven Dimensions, Nucl. Phys. B796 (2008) 521, arXiv:0709.0398
"... We consider realizations of GUT models in Ftheory. Adopting a bottom up approach, the assumption that the dynamics of the GUT model can in principle decouple from Planck scale physics leads to a surprisingly predictive framework. An internal U(1) hypercharge flux Higgses the GUT group directly to t ..."
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We consider realizations of GUT models in Ftheory. Adopting a bottom up approach, the assumption that the dynamics of the GUT model can in principle decouple from Planck scale physics leads to a surprisingly predictive framework. An internal U(1) hypercharge flux Higgses the GUT group directly to the MSSM or to a flipped GUT model, a mechanism unavailable in heterotic models. This new ingredient automatically addresses a number of puzzles present in traditional GUT models. The internal U(1) hyperflux allows us to solve the doublettriplet splitting problem, and explains the qualitative features of the distorted GUT mass relations for lighter generations due to the AharanovBohm effect. These models typically come with nearly exact global symmetries which prevent bare µ terms and also forbid dangerous baryon number violating operators. Strong curvature around our brane leads to a repulsion mechanism for Landau wave functions for neutral fields. This leads to large hierarchies of the form exp(−c/ε 2γ) where c and γ are order one parameters and ε ∼ α −1 GUT MGUT/Mpl. This effect can simultaneously generate a