5,479 research outputs found

    LHC physics: the first one--two year(s)

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    We discuss the strategy to commission the LHC experiments and understand standard physics at sqrt{s}=14TeV before data taking starts and in the early phases of the LHC operation. In particular, we review the various steps needed to understand and calibrate the ATLAS and CMS detectors, from construction quality checks, to beam tests, to cosmics runs, to first collisions. We also review the preparation and tuning of Monte Carlo tools, and present a few examples of physics goals for integrated luminosities of up to a few inverse fb.Comment: Proceedings of the 2nd Italian Workshop on the physics of Atlas and CM

    The Turin fluvial terraces as evidence of the new Holocene setting of the Po River

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    A detailed geomorphological mapping of the Po River fluvial terraces into Turin was performed through a field survey. Although Turin is crossed by the Po River, most of the town is built on the extended alpine outwash fans linked to its tributaries (essentially fed by the Dora Riparia Basin), made by 20–60 m thick gravel with sand lenses, or on erosional terraces (T1 and T2) shaped by the Po River into these sediments. Only a small sector of the town is built on a narrow belt formed by thin soft sand deposited by the Po, forming depositional terraces (T3 and T4) entrenched in the alpine fans. This research allowed us to recognize three steps in the geological evolution of the area: the construction of the alpine fans (Last Glacial Maximum), the first flow of the Po River that erodes the tributary sediments (Lateglacial-Holocene) and the deposition by Po River (Holocene)

    Are There Hints of Light Stops in Recent Higgs Search Results?

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    The recent discovery at the LHC by the CMS and ATLAS collaborations of the Higgs boson presents, at long last, direct probes of the mechanism for electroweak symmetry breaking. While it is clear from the observations that the new particle plays some role in this process, it is not yet apparent whether the couplings and widths of the observed particle match those predicted by the Standard Model. In this paper, we perform a global fit of the Higgs results from the LHC and Tevatron. While these results could be subject to as-yet-unknown systematics, we find that the data are significantly better fit by a Higgs with a suppressed width to gluon-gluon and an enhanced width to gamma gamma, relative to the predictions of the Standard Model. After considering a variety of new physics scenarios which could potenially modify these widths, we find that the most promising possibility is the addition of a new colored, charged particle, with a large coupling to the Higgs. Of particular interest is a light, and highly mixed, stop, which we show can provide the required alterations to the combination of gg and gamma gamma widths.Comment: 6 pages, 5 figure

    The Higgs boson in the MSSM in light of the LHC

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    We investigate the expectations for the light Higgs signal in the MSSM in different search channels at the LHC. After taking into account dark matter and flavor constraints in the MSSM with eleven free parameters, we show that the light Higgs signal in the gammaγgamma\gamma channel is expected to be at most at the level of the SM Higgs, while the hbbˉh\rightarrow b\bar{b} from W fusion and/or the hττˉh \rightarrow\tau\bar\tau can be enhanced. For the main discovery mode, we show that a strong suppression of the signal occurs in two different cases: low MAM_A or large invisible width. A more modest suppression is associated with the effect of light supersymmetric particles. Looking for such modification of the Higgs properties and searching for supersymmetric partners and pseudoscalar Higgs offer two complementary probes of supersymmetry.Comment: 19 pages, 8 figure

    The incidence of injuries traveling to and from school by travel mode

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    Objective. To assess the absolute and relative risks of youth school-related travel using the New Zealand's no fault accident liability scheme and Census at School datasets. Methods. Injury risk associated with traveling to and from school was assessed by combining census data from the Accident Compensation Commission database, New Zealand's no fault liability accident scheme database and the Census at School survey. Population injury and cost was assessed for incidents during a 2-year period (1 July 2003 to 30 June 2005) and during normal school travel hours (7.30 a.m.–9.00 a.m., 3.00 p.m.–4.30 p.m., weekdays) for youth 5–17 years of age. Results. Overall, 7573 cases were identified as being school travel-related, representing 1.6% of total, and 11.4% school travel period injuries. Walking (30.7%), cycling (30.3%), and motor vehicles (27.7%) provided the majority of injuries. Risk of injury per million trips was highest for cycling (46.1), walking (10.3), and motor vehicle travel (6.1). Conclusion. These data provide the first comprehensive examination of absolute risk of travel to and from school and by transport mode, showing that school-related travel is a relatively safe activity contributing to a minority of all injuries sustained by youth

    The Gaugephobic Higgs

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    We present a class of models that contains Randall-Sundrum and Higgsless models as limiting cases. Over a wide range of the parameter space WW scattering is mainly unitarized by Kaluza-Klein partners of the W and Z, and the Higgs particle has suppressed couplings to the gauge bosons. Such a gaugephobic Higgs can be significantly lighter than the 114 GeV LEP bound for a standard Higgs, or heavier than the theoretical upper bound. These models predict a suppressed single top production rate and unconventional Higgs phenomenology at the LHC: the Higgs production rates will be suppressed and the Higgs branching fractions modified. However, the more difficult the Higgs search at the LHC is, the easier the search for other light resonances (like Z', W', t', exotic fermions) will be.Comment: 20 pages, 3 figure
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