5,479 research outputs found
LHC physics: the first one--two year(s)
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
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?
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
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 channel is expected to be at most at
the level of the SM Higgs, while the from W fusion
and/or the can be enhanced. For the main discovery
mode, we show that a strong suppression of the signal occurs in two different
cases: low 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
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
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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