Higgs Boson Searches Beyond the Standard Model with ATLAS

Recent searches for Higgs bosons in the context of extensions to the Standard Model of Particle Physics with the ATLAS detector at the Large Hadron Collider are discussed. All presented analyses use data recorded at a pp center-of-mass energy of 7 TeV in 2011 with integrated luminosities between 1 and 5/fb. No significant deviations from the background expectations are found and corresponding constraints on physics beyond the Standard Model are obtained.Comment: 4 pages, Contribution to the proceedings of the Rencontres de Moriond QCD 201

Open Beauty Production at HERA

Recent results on open beauty production in positron-proton collisions at a centre-of-mass energy of 300 GeV are presented. The beauty photoproduction cross section is measured by ZEUS and H1 via the semileptonic decay. Both experiments use the transverse lepton momentum with respect to a jet as an observable. The H1 central silicon vertex detector makes it possible to analyse, in addition, the lepton impact parameter spectrum, thus exploiting lifetime information for the first time at HERA. The combined lifetime and transverse momentum signature is further used to observe beauty production for the first time in deep inelastic scattering. All results are compared with NLO QCD calculations.Comment: Proceedings, DIS 2001, Bologna, Italy. 4 pages, 4 figure

Studies of Rare Hadronic B Decays with BaBar

We present a selection of recent results from studies of rare hadronic B decays based on a sample of 232 million B{bar B} pairs, corresponding to an integrated luminosity of 211 fb{sup -1}, which were recorded with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring

Search for new physics from B→πϕB\to\pi \phi

We investigate the pure penguin process $B^-\to \pi^-\phi$ using QCD factorization approach to calculate hadronic matrix elements to the $\alpha_s$ order in some well-known NP models. It is shown that the NP contributions in R-parity conserved SUSY models and 2HDMs are not enough to saturate the experimental upper bounds for $B\to \phi \pi$. We have shown that the flavor changing $Z^\prime$ models can make the branching ratios of $B\to \phi \pi$ to saturate the bound under all relevant experimental constraints.Comment: No figure

Physics at the e+ e- Linear Collider

A comprehensive review of physics at an e+e- Linear Collider in the energy range of sqrt{s}=92 GeV--3 TeV is presented in view of recent and expected LHC results, experiments from low energy as well as astroparticle physics.The report focuses in particular on Higgs boson, Top quark and electroweak precision physics, but also discusses several models of beyond the Standard Model physics such as Supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analyzed as well.Comment: 179 pages, plots and references updated, version to be published at EPJ

Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA

Deep-inelastic positron-proton interactions at low values of Bjorken-x down to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons are studied with the H1 experiment at HERA. The inclusive cross section for pi^0 mesons produced at small angles with respect to the proton remnant (the forward region) is presented as a function of the transverse momentum and energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x. Measurements are also presented of the transverse energy flow in events containing a forward pi^0 meson. Hadronic final state calculations based on QCD models implementing different parton evolution schemes are confronted with the data.Comment: 27 pages, 8 figures and 3 table

Deep-Inelastic Inclusive ep Scattering at Low x and a Determination of alpha_s

A precise measurement of the inclusive deep-inelastic e^+p scattering cross section is reported in the kinematic range 1.5<= Q^2 <=150 GeV^2 and 3*10^(-5)<= x <=0.2. The data were recorded with the H1 detector at HERA in 1996 and 1997, and correspond to an integrated luminosity of 20 pb^(-1). The double differential cross section, from which the proton structure function F_2(x,Q^2) and the longitudinal structure function F_L(x,Q^2) are extracted, is measured with typically 1% statistical and 3% systematic uncertainties. The measured partial derivative (dF_2(x,Q^2)/dln Q^2)_x is observed to rise continuously towards small x for fixed Q^2. The cross section data are combined with published H1 measurements at high Q^2 for a next-to-leading order DGLAP QCD analysis.The H1 data determine the gluon momentum distribution in the range 3*10^(-4)<= x <=0.1 to within an experimental accuracy of about 3% for Q^2 =20 GeV^2. A fit of the H1 measurements and the mu p data of the BCDMS collaboration allows the strong coupling constant alpha_s and the gluon distribution to be simultaneously determined. A value of alpha _s(M_Z^2)=0.1150+-0.0017 (exp) +0.0009-0.0005 (model) is obtained in NLO, with an additional theoretical uncertainty of about +-0.005, mainly due to the uncertainty of the renormalisation scale.Comment: 68 pages, 24 figures and 18 table