386 research outputs found
Exploiting the WH/ZH symmetry in the search for New Physics
We suggest to isolate the loop-induced gluon-initiated component ()
for associated production by using the similarity of the Drell-Yan-like
component for production to the process. We argue that the
cross-section ratio of the latter two processes can be predicted with high
theoretical accuracy. Comparing it to the experimental cross-section
ratio should allow to probe for New Physics in the component at the
HL-LHC. We consider typical BSM scenarios in order to exemplify the effect they
would have on the proposed observable.Comment: 22 pages, 10 figures. v2: Minor changes; matches published versio
Effects of QCD radiation on inclusive variables for determining the scale of new physics at hadron colliders
We examine the effects of QCD initial-state radiation on a class of
quantities, designed to probe the mass scale of new physics at hadron
colliders, which involve longitudinal as well as transverse final-state
momenta. In particular, we derive universal functions that relate the invariant
mass and energy distribution of the visible part of the final state to that of
the underlying hard subprocess. Knowledge of this relationship may assist in
checking hypotheses about new processes, by providing additional information
about their scales. We compare our results with those of Monte Carlo studies
and find good general agreement
Effects of invisible particle emission on global inclusive variables at hadron colliders
We examine the effects of invisible particle emission in conjunction with QCD
initial state radiation (ISR) on quantities designed to probe the mass scale of
new physics at hadron colliders, which involve longitudinal as well as
transverse final-state momenta. This is an extension of our previous treatment,
arXiv:0903.2013, of the effects of ISR on global inclusive variables. We
present resummed results on the visible invariant mass distribution and compare
them to parton-level Monte Carlo results for top quark and gluino
pair-production at the LHC. There is good agreement as long as the visible
pseudorapidity interval is large enough (eta ~ 3). The effect of invisible
particle emission is small in the case of top pair production but substantial
for gluino pair production. This is due mainly to the larger mass of the
intermediate particles in gluino decay (squarks rather than W-bosons). We also
show Monte Carlo modelling of the effects of hadronization and the underlying
event. The effect of the underlying event is large but may be approximately
universal.Comment: 22 pages, expanded sections and other minor modifications. Version
published in JHE
A study of multi-jet production in association with an electroweak vector boson
Abstract: We consider the production of a single Z or W boson in association with jets at the LHC. We compute the corresponding cross sections by matching NLO QCD predictions with the Herwig++ and Pythia8 parton showers, and by merging all of the underlying matrix elements with up to two light partons at the Born level. We compare our results with several 7-TeV measurements by the ATLAS and CMS collaborations, and overall we find a good agreement between theory and data
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