Production of a Z boson and two jets with one heavy-quark tag

We present a next-to-leading-order calculation of the production of a Z boson with two jets, one or more of which contains a heavy quark (Q=c,b). We show that the cross section with only one heavy-quark jet is larger than that with two heavy-quark jets at both the Fermilab Tevatron and the CERN LHC. These processes are the dominant irreducible backgrounds to a Higgs boson produced in association with a Z boson, followed by h->bb. Our calculation makes use of a heavy-quark distribution function, which resums collinear logarithms and makes the next-to-leading-order calculation tractable.Comment: 11 pages, 5 figures. Erratum adde

Higgs production in association with bottom quarks

We study the production of a Higgs boson in association with bottom quarks in hadronic collisions, and present phenomenological predictions relevant to the 13 TeV LHC. Our results are accurate to the next-to-leading order in QCD, and matched to parton showers through the MC@NLO method; thus, they are fully differential and based on unweighted events, which we shower by using both Herwig++ and Pythia8. We perform the computation in both the four-flavour and the five-flavour schemes, whose results we compare extensively at the level of exclusive observables. In the case of the Higgs transverse momentum, we also consider the analytically-resummed cross section up to the NNLO+NNLL accuracy. In addition, we analyse at ${\cal O}(\alpha_S^3)$ the effects of the interference between the $b\bar{b}H$ and gluon-fusion production modes.Comment: 33 pages, 17 figure

Forward jets and forward WW-boson production at hadron colliders

In this talk we give a short review of forward jets and forward $W$-boson production at hadron colliders, in view of the extraction of footprints of BFKL physics. We argue that at Tevatron energies, dijet production at large rapidity intervals is still subasymptotic with respect to the BFKL regime, thus the cross section is strongly dependent on the various cuts applied in the experimental setup. In addition, the choice of equal transverse momentum cuts on the tagging jets makes the cross section dependent on large logarithms of non-BFKL origin, and thus may spoil the BFKL analysis. For vector boson production in association with two jets, we argue that the configurations that are kinematically favoured tend to have the vector boson forward in rapidity. Thus $W + 2$ jet production lends itself naturally to extensions to the high-energy limit.Comment: LaTeX, JHEP style, 10 pages, 3 figures. Based on a talk at EPS2001, Budapest, Hungar

Constraints on a scalar-pseudoscalar Higgs mixing at future e+e- colliders: an update

We perform an update of our previous analysis on the constraints on possible deviations of Hbb coupling from its Standard Model value, arising from a scalar-pseudoscalar mixing. In this paper we include a complete simulation of the process e+ e- -> b bbar e+ e- and combine it with our previous results to obtain tighter bounds on the deviations of the parameters describing this coupling that could be measured at the Next Linear Collider.Comment: 3 pages, 2 figures, to be submitted to Phys. Rev.

Detecting Double-Identity Fingerprint Attacks

Double-identity biometrics, that is the combination of two subjects features into a single template, was demonstrated to be a serious threat against existing biometric systems. In fact, well-synthetized samples can fool state-of-the-art biometric verification systems, leading them to falsely accept both the contributing subjects. This work proposes one of the first techniques to defy existing double-identity fingerprint attacks. The proposed approach inspects the regions where the two aligned fingerprints overlap but minutiae cannot be consistently paired. If the quality of these regions is good enough to minimize the risk of false or miss minutiae detection, then the alarm score is increased. Experimental results carried out on two fingerprint databases, with two different techniques to generate double-identity fingerprints, validate the effectiveness of the proposed approach

Higgs pair production at the LHC with NLO and parton-shower effects

We present predictions for the SM-Higgs-pair production channels of relevance at the LHC: gluon-gluon fusion, VBF, and top-pair, W, Z and single-top associated production. All these results are at the NLO accuracy in QCD, and matched to parton showers by means of the MC@NLO method; hence, they are fully differential. With the exception of the gluon-gluon fusion process, for which a special treatment is needed in order to improve upon the infinite-top-mass limit, our predictions are obtained in a fully automatic way within the publicly available MadGraph5_aMC@NLO framework. We show that for all channels in general, and for gluon-gluon fusion and top-pair associated production in particular, NLO corrections reduce the theoretical uncertainties, and are needed in order to arrive at reliable predictions for total rates as well as for distributions.Comment: 11 pages, 7 figures, version accepted for publication on PL

Associated Production of a W Boson and One b Jet

We calculate the production of a W boson and a single b jet to next-to-leading order in QCD at the Fermilab Tevatron and the CERN Large Hadron Collider. Both exclusive and inclusive cross sections are presented. We separately consider the cross section for jets containing a single b quark and jets containing a b-anti b pair. There are a wide variety of processes that contribute, and it is necessary to include them all in order to have a complete description at both colliders.Comment: LaTeX, 16 pages, 22 postscript figures; version published in Phys. Rev.

Confusing Sterile Neutrinos with Deviation from Tribimaximal Mixing at Neutrino Telescopes

We expound the impact of extra sterile species on the ultra high energy neutrino fluxes in neutrino telescopes. We use three types of well-known flux ratios and compare the values of these flux ratios in presence of sterile neutrinos, with those predicted by deviation from the tribimaximal mixing scheme. We show that in the upcoming neutrino telescopes, its easy to confuse between the signature of sterile neutrinos with that of the deviation from tribimaximal mixing. We also show that if the measured flux ratios acquire a value well outside the range predicted by the standard scenario with three active neutrinos only, it might be possible to tell the presence of extra sterile neutrinos by observing ultra high energy neutrinos in future neutrino telescopes.Comment: 22 pages, version to appear in Phys. Rev.

Precision Calculations for Future Colliders

I discuss the motivations for, and the status of, precision calculations for the Large Hadron Collider (LHC) and the planned International Linear Collider (ILC).Comment: latex, uses ws-ijmpe.cls, 19 pages, 9 figures, 1 table, based on a talk given at the symposium "50 Years of High Energy Physics at UB", to appear in International Journal of Modern Physics