4,334 research outputs found
Automated NLO QCD Corrections with WHIZARD
We briefly discuss the current status of NLO QCD automation in the Monte
Carlo event generator WHIZARD. The functionality is presented for the explicit
study of off-shell top quark production with associated backgrounds at a lepton
collider.Comment: 9 pages, 5 figures, to appear in the proceedings of the European
Physical Society Conference on High Energy Physics 2015 (EPS-HEP 2015),
Vienna, Austria, 22nd to 29th of July 201
Matching NLO QCD Corrections in WHIZARD with the POWHEG scheme
Building on the new automatic subtraction of NLO amplitudes in WHIZARD, we
present our implementation of the POWHEG scheme to match radiative corrections
consistently with the parton shower. We apply this general framework to two
linear collider processes, and
.Comment: 7 pages, 4 figures, to appear in the proceedings of the European
Physical Society Conference on High Energy Physics 2015 (EPS-HEP 2015),
Vienna, Austria, 22nd to 29th of July 201
Hunting for neutral, long-lived exotica at the LHC using a missing transverse energy signature
Searches at the Large Hadron Collider (LHC) for neutral, long-lived particles
have historically relied on the detection of displaced particles produced by
their decay the detector volume. In this paper we study the
potential of the complementary signature comprising of the missing transverse
energy () signal, traditionally used to look for dark matter, e.g.,
the lightest supersymmetric particle (LSP), to extend the LHC coverage to
models with long-lived (LL) particles when they decay the
detector. Using CMS and ATLAS analyses at the 8 TeV LHC, we set an upper limit
at the 95% confidence level (CL) on the production cross sections for two
specific scenarios: (i) a model with a heavy non-standard model Higgs boson
decaying to a LL scalar and (ii) an R-parity violating RPV SUSY model with a LL
neutralino.
We show that this method can significantly extend the LHC sensitivity to
neutral, LL particles with arbitrary large lifetimes and that the limits
obtained from a signal are comparable to those from displaced
particle searches for decay distances above a few meters. Results obtained in
this study do not not depend on the specific decay channel of the LL particle
and therefore are model-independent in this sense. We provide limits for the
whole two-dimensional plane in terms of the mass of the LL particle and the
mass of the mediator up to masses of 2 TeV including particular benchmarks
studied in the original experimental papers. We have made these limits
available in the form of a grid which can be used for the interpretation of
various other new physics models.Comment: 28 page
The relationship between two flavors of oblivious transfer at the quantum level
Though all-or-nothing oblivious transfer and one-out-of-two oblivious
transfer are equivalent in classical cryptography, we here show that due to the
nature of quantum cryptography, a protocol built upon secure quantum
all-or-nothing oblivious transfer cannot satisfy the rigorous definition of
quantum one-out-of-two oblivious transfer.Comment: 4 pages, no figur
QCD NLO with Powheg matching and top threshold matching in WHIZARD
We present the status of the automation of NLO processes within the event
generator WHIZARD. The program provides an automated FKS subtraction and phase
space integration over the FKS regions, while the (QCD) NLO matrix element is
accessed via the Binoth Les Houches Interface from an externally linked
one-loop program. Massless and massive test cases and validation are shown for
several e+e- processes. Furthermore, we discuss work in progress and future
plans. The second part covers the matching of the NRQCD prediction with NLL
threshold resummation to the NLO continuum top pair production at lepton
colliders. Both the S-wave and P-wave production of the top pair are taken into
account in the resummation. The inclusion in WHIZARD allows to study more
exclusive observables than just the total cross section and automatically
accounts for important electroweak and relativistic corrections in the
threshold region.Comment: 9 pages, 3 figures, Talk given at 12th International Symposium on
Radiative Corrections (Radcor 2015) and LoopFest XIV (Radiative Corrections
for the LHC and Future Colliders); v2: reference adde
Multistable alignment states in nematic liquid crystal filled wells
Two distinct, stable alignment states have been observed for a nematic liquid crystal confined in a layer with thickness of 12 μm and in square wells with sides of length between 20 and 80 μm. The director lies in the plane of the layer and line defects occur in two corners of the squares. The positions of the defects determine whether the director orientation is across the diagonal or is parallel to two opposite edges of the square. The device is multistable because both the diagonal and parallel states are stable when rotated by multiples of 90° in plane
Queering Art Before, After and During the Sexual Revolution (1960-1980): A Study of Aesthetics and Subversion
Works produced by the queer artists in 1970s America is oftentimes not considered to be an integral part of the sexual revolution’s narrative. Not only is this problematic in that it demonstrates the heteronormative discourse that permeated liberatory pro-sex rhetoric of the time, but this exclusion also makes the LGBTQ struggle for visibility ahistorical. In this paper, I argue that notable artists who self-identified as lesbian, gay, bisexual, transgender or queer created art that fostered gradual acceptance of the queer community before, during and after the sexual revolution, explaining that resistance to dominant paradigms were rendered unseen due to the intertwined nature of various social movements of the time, such as second-wave feminism, a reaction that would eventually lead to LGBTQ artists being marginalized again until the AIDS epidemic of the 1980s
Automation of NLO processes and decays and POWHEG matching in WHIZARD
We give a status report on the automation of next-to-leading order processes
within the Monte Carlo event generator WHIZARD, using GoSam and OpenLoops as
provider for one-loop matrix elements. To deal with divergences, WHIZARD uses
automated FKS subtraction, and the phase space for singular regions is
generated automatically. NLO examples for both scattering and decay processes
with a focus on e+e- processes are shown. Also, first NLO-studies of
observables for collisions of polarized leptons beams, e.g. at the ILC, will be
presented. Furthermore, the automatic matching of the fixed-order NLO
amplitudes with emissions from the parton shower within the POWHEG formalism
inside WHIZARD will be discussed. We also present results for top pairs at
threshold in lepton collisions, including matching between a resummed threshold
calculation and fixed-order NLO. This allows the investigation of more
exclusive differential observables.Comment: 5 pages, 3 figures, Talk presented at ACAT 2016 at UTFSM,
Valpara\'iso, Chil
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