7,701 research outputs found
The CMS Discovery Potential of Supersymmetry within mSugra with two same sign muons
A detailed study of the same-sign muon signature within the mSUGRA model was performed. Selection criteria based on the missing transverse energy in the events and the jet and muon transverse momenta are applied to select the data sample. An excess of SUSY events over the standard model background processes can be statistically significant for many benchmark points for an integrated luminosity of less than 10 fb/sup -1detailed detector simulation, trigger emulation and reconstruction were performed
Constraint Likelihood analysis for a network of gravitational wave detectors
We propose a coherent method for the detection and reconstruction of
gravitational wave signals for a network of interferometric detectors. The
method is derived using the likelihood functional for unknown signal waveforms.
In the standard approach, the global maximum of the likelihood over the space
of waveforms is used as the detection statistic. We identify a problem with
this approach. In the case of an aligned pair of detectors, the detection
statistic depends on the cross-correlation between the detectors as expected,
but this dependence dissappears even for infinitesimally small misalignments.
We solve the problem by applying constraints on thelikelihood functional and
obtain a new class of statistics. The resulting method can be applied to the
data from a network consisting of any number of detectors with arbitrary
detector orientations. The method allows us reconstruction of the source
coordinates and the waveforms of two polarization components of a gravitational
wave. We study the performance of the method with numerical simulation and find
the reconstruction of the source coordinates to be more accurate than in the
standard approach.Comment: 13 pages, 6 figure
Measuring Muon Reconstruction Efficiency from Data
We suggest a method of measuring the global muon reconstruction efficiency epsilon directly from data, which largely alleviates uncertainties associated with our ability to monitor and reproduce in Monte Carlo simulation all details of the underlying detector performance. With the data corresponding to an integrated luminosity L = 10 fb^-1, the precision of measuring epsilon for muons in the P_T range of 10-100~GeV will be better than 1%
Variability of signal to noise ratio and the network analysis of gravitational wave burst signals
The detection and estimation of gravitational wave burst signals, with {\em a
priori} unknown polarization waveforms, requires the use of data from a network
of detectors. For determining how the data from such a network should be
combined, approaches based on the maximum likelihood principle have proven to
be useful. The most straightforward among these uses the global maximum of the
likelihood over the space of all waveforms as both the detection statistic and
signal estimator. However, in the case of burst signals, a physically
counterintuitive situation results: for two aligned detectors the statistic
includes the cross-correlation of the detector outputs, as expected, but this
term disappears even for an infinitesimal misalignment. This {\em two detector
paradox} arises from the inclusion of improbable waveforms in the solution
space of maximization. Such waveforms produce widely different responses in
detectors that are closely aligned. We show that by penalizing waveforms that
exhibit large signal-to-noise ratio (snr) variability, as the corresponding
source is moved on the sky, a physically motivated restriction is obtained that
(i) resolves the two detector paradox and (ii) leads to a better performing
statistic than the global maximum of the likelihood. Waveforms with high snr
variability turn out to be precisely the ones that are improbable in the sense
mentioned above. The coherent network analysis method thus obtained can be
applied to any network, irrespective of the number or the mutual alignment of
detectors.Comment: 13 pages, 6 figure
A burst search for gravitational waves from binary black holes
Compact binary coalescence (CBC) is one of the most promising sources of
gravitational waves. These sources are usually searched for with matched
filters which require accurate calculation of the GW waveforms and generation
of large template banks. We present a complementary search technique based on
algorithms used in un-modeled searches. Initially designed for detection of
un-modeled bursts, which can span a very large set of waveform morphologies,
the search algorithm presented here is constrained for targeted detection of
the smaller subset of CBC signals. The constraint is based on the assumption of
elliptical polarisation for signals received at the detector. We expect that
the algorithm is sensitive to CBC signals in a wide range of masses, mass
ratios, and spin parameters. In preparation for the analysis of data from the
fifth LIGO-Virgo science run (S5), we performed preliminary studies of the
algorithm on test data. We present the sensitivity of the search to different
types of simulated CBC waveforms. Also, we discuss how to extend the results of
the test run into a search over all of the current LIGO-Virgo data set.Comment: 12 pages, 4 figures, 2 tables, submitted for publication in CQG in
the special issue for the conference proceedings of GWDAW13; corrected some
typos, addressed some minor reviewer comments one section restructured and
references updated and correcte
SUSY Survey with Inclusive Muon and Same-Sign Dimuon Accompanied by Jets and MET with CMS
Generic signatures of supersymmetry with R-parity conservation include those of single isolated muons or like-sign isolated dimuon pairs, accompanied with energetic jets and missing transverse energy. The ability of CMS to discover supersymmetry with these signals is estimated for 10 fb^{-1} of data collected with the inclusive single-muon and dimuon High-Level-Trigger paths. The selection criteria are optimized and the systematic effects are studied for a single low-mass benchmark point of the constrained MSSM with m_0 = 60,GeV/c^2, m_{1/2} = 250,GeVc^2, tan beta=10, A_0=0 and mu> 0. Discovery contours in the m_0, m_{1/2}) plane are presented for integrated luminosities ranging from 1 to 100, fb^{-1}
Potential to Discover Supersymmetry in Events with Muons, Jets and Missing Energy in pp Collisions at = 14 TeV with the CMS Detector
Generic signatures of supersymmetry with R-Parity conservation include those of single isolated muons or like-sign isolated dimuon pairs, accompanied with energetic jets and missing transverse energy. The ability of CMS to discover supersymmetry with these signals is estimated for 10 fb^-1 of collected data with the inclusive single- and di-muon High Level Trigger paths. The selection criteria are optimized and the systematic effects are studied for a single low-mass benchmark point of the constrained MSSM with m_0 = 60 GeV/c^2, m_1/2 = 250 GeV/c^2, tan beta = 10, A_0 = 0, and mu > 0. Discovery contours in the (m_0, m_1/2) plane are presented for integrated luminosities ranging from 1 to 100 fb^-1
Tevatron-for-LHC Report: Preparations for Discoveries
This is the "TeV4LHC" report of the "Physics Landscapes" Working Group,
focused on facilitating the start-up of physics explorations at the LHC by
using the experience gained at the Tevatron. We present experimental and
theoretical results that can be employed to probe various scenarios for physics
beyond the Standard Model.Comment: 222 pp., additional contribution added, typos/layout correcte
Networks of gravitational wave detectors and three figures of merit
This paper develops a general framework for studying the effectiveness of
networks of interferometric gravitational wave detectors and then uses it to
show that enlarging the existing LIGO-VIRGO network with one or more planned or
proposed detectors in Japan (LCGT), Australia, and India brings major benefits,
including much larger detection rate increases than previously thought... I
show that there is a universal probability distribution function (pdf) for
detected SNR values, which implies that the most likely SNR value of the first
detected event will be 1.26 times the search threshold. For binary systems, I
also derive the universal pdf for detected values of the orbital inclination,
taking into account the Malmquist bias; this implies that the number of
gamma-ray bursts associated with detected binary coalescences should be 3.4
times larger than expected from just the beaming fraction of the gamma burst.
Using network antenna patterns, I propose three figures of merit that
characterize the relative performance of different networks... Adding {\em any}
new site to the planned LIGO-VIRGO network can dramatically increase, by
factors of 2 to 4, the detected event rate by allowing coherent data analysis
to reduce the spurious instrumental coincident background. Moving one of the
LIGO detectors to Australia additionally improves direction-finding by a factor
of 4 or more. Adding LCGT to the original LIGO-VIRGO network not only improves
direction-finding but will further increase the detection rate over the
extra-site gain by factors of almost 2, partly by improving the network duty
cycle... Enlarged advanced networks could look forward to detecting three to
four hundred neutron star binary coalescences per year.Comment: 38 pages, 7 figures, 2 tables. Accepted for publication in Classical
and Quantum Gravit
- …