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1.
Mao, Zaixing.
Search for New Physics with Tau Lepton Final States.
Degree: Department of Physics, 2017, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:733436/ 
► The Standard Model (SM) of particle physics has proven to be a very successful theory in explaining many experimental observations involving electroweak and strong interactions.…
(more)
▼ The Standard Model (SM) of particle physics has proven
to be a very successful theory in explaining many experimental
observations involving electroweak and strong interactions.
Nevertheless, the SM is an incomplete theory as it does not
describe gravity. The inclusion of gravity requires a theory that
is valid up to the Planck scale. If no new physics resides above
the SM, running the SM up to the Planck scale leads to divergence
terms in the Higgs mass calculation. With the observation of the
Higgs boson at 125 GeV, this can only be achieved by a large amount
of fine-tuning to the SM parameters, known as the Hierarchy
problem. Thus, many theories Beyond the Standard Model (BSM) were
proposed. This thesis presents searches for new elementary
particles through their decays to tau leptons using the data
collected by the Compact Muon Solenoid (CMS). First, a search for a
massive Higgs boson is presented in the context of the Minimal
Supersymmetry Standard Model (MSSM). The MSSM tackles the Hierarchy
problem by predicting super partners to the SM particles. These new
particles introduce extra correction terms in the Higgs mass
calculation and automatically cancel out the diverging terms which
need fine-tuning. Here, the decay channel of H → hh → 𝜏𝜏bb is
studied with a tau, anti-tau lepton pair and a b, anti-b quark pair
as the final state. The second part of the thesis focuses on the
search for a new neutral gauge boson, denoted as Z’. Many BSM
theories, ranging from Grand Unification Theories, which hope to
unite the strong and electroweak interactions, to the Little Higgs
Model, all predict the presence of extra gauge bosons. In this
thesis, we present the search for the Z’ boson through its decay
into a pair of tau, anti-tau leptons in the context of the
Sequential Standard Model.
Advisors/Committee Members: Heintz, Ulrich (Advisor), Cutts, David (Reader), Fan, Jiji (Reader).
Subjects/Keywords: New Physics
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APA (6th Edition):
Mao, Z. (2017). Search for New Physics with Tau Lepton Final States. (Thesis). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:733436/
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mao, Zaixing. “Search for New Physics with Tau Lepton Final States.” 2017. Thesis, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:733436/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mao, Zaixing. “Search for New Physics with Tau Lepton Final States.” 2017. Web. 01 Mar 2021.
Vancouver:
Mao Z. Search for New Physics with Tau Lepton Final States. [Internet] [Thesis]. Brown University; 2017. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:733436/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mao Z. Search for New Physics with Tau Lepton Final States. [Thesis]. Brown University; 2017. Available from: https://repository.library.brown.edu/studio/item/bdr:733436/
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
2.
PARIHAR, Vivek Singh.
A Measurement of the Top Quark Mass in the Lepton + Jets
Channel using the Ideogram Technique at D\O\.
Degree: PhD, Physics, 2013, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:320495/
► This thesis presents a measurement of the mass of the top quark. The top quarks are produced through proton-antiproton collisions with √{s}=1.96 TeV at the…
(more)
▼ This thesis presents a measurement of the mass of the
top quark. The top quarks are produced through proton-antiproton
collisions with √{s}=1.96 TeV at the Fermilab Tevatron
collider using the D\O detector. The method employed for the
measurement is called the Ideogram Technique. The events used in
the measurement are selected such that the top quark decay
signatures (as seen in the detector) are at least one lepton
(electron or muon), four or more jets with at least one of them
tagged as originating from a b-quark and missing transverse
momentum. These events are then fitted using a kinematic fitter.
The event-by-event likelihood is calculated using templates that
depend on the kinematically reconstructed top quark mass. The
events are weighted by their probability to be signal or
background, using topological information. The measurement of the
top quark mass is 175.7±1.98 GeV/c
2.
Advisors/Committee Members: Heintz, Ulrich (Director), Cutts, David (Reader), Narain, Meenakshi (Reader).
Subjects/Keywords: top quark mass
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APA (6th Edition):
PARIHAR, V. S. (2013). A Measurement of the Top Quark Mass in the Lepton + Jets
Channel using the Ideogram Technique at D\O\. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:320495/
Chicago Manual of Style (16th Edition):
PARIHAR, Vivek Singh. “A Measurement of the Top Quark Mass in the Lepton + Jets
Channel using the Ideogram Technique at D\O\.” 2013. Doctoral Dissertation, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:320495/.
MLA Handbook (7th Edition):
PARIHAR, Vivek Singh. “A Measurement of the Top Quark Mass in the Lepton + Jets
Channel using the Ideogram Technique at D\O\.” 2013. Web. 01 Mar 2021.
Vancouver:
PARIHAR VS. A Measurement of the Top Quark Mass in the Lepton + Jets
Channel using the Ideogram Technique at D\O\. [Internet] [Doctoral dissertation]. Brown University; 2013. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:320495/.
Council of Science Editors:
PARIHAR VS. A Measurement of the Top Quark Mass in the Lepton + Jets
Channel using the Ideogram Technique at D\O\. [Doctoral Dissertation]. Brown University; 2013. Available from: https://repository.library.brown.edu/studio/item/bdr:320495/
3.
Alimena, Juliette.
A search for long-lived particles that stop in the CMS
detector and decay to muons.
Degree: PhD, Physics, 2016, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:674170/
► A search for long-lived particles that are produced in proton-proton collisions at the CERN LHC, come to rest in the CMS detector, and decay to…
(more)
▼ A search for long-lived particles that are produced in
proton-proton collisions at the CERN LHC, come to rest in the CMS
detector, and decay to muons is presented. The decays of the
stopped particles could be observed during the intervals between
LHC beam crossings, at times that are well separated from any
proton-proton collisions. The analysis uses 19.7 1/fb of 8 TeV data
collected by CMS in 2012, during a search interval of 293 hours of
trigger livetime. Massive, long-lived particles do not exist in the
Standard Model, and so any sign of them would be an indication of
new physics. The results are interpreted with a model that predicts
a long-lived particle that has a charge of twice the electron
charge and that behaves like a lepton. Cross section limits are set
for each long-lived particle mass as a function of lifetime, for
lifetimes between 100 ns and 10 days. These are the first limits
for long-lived stopped particles that decay to muons.
Advisors/Committee Members: Cutts, David (Director), Narain, Meenakshi (Reader), Fan, JiJi (Reader).
Subjects/Keywords: particle physics
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APA (6th Edition):
Alimena, J. (2016). A search for long-lived particles that stop in the CMS
detector and decay to muons. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:674170/
Chicago Manual of Style (16th Edition):
Alimena, Juliette. “A search for long-lived particles that stop in the CMS
detector and decay to muons.” 2016. Doctoral Dissertation, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:674170/.
MLA Handbook (7th Edition):
Alimena, Juliette. “A search for long-lived particles that stop in the CMS
detector and decay to muons.” 2016. Web. 01 Mar 2021.
Vancouver:
Alimena J. A search for long-lived particles that stop in the CMS
detector and decay to muons. [Internet] [Doctoral dissertation]. Brown University; 2016. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:674170/.
Council of Science Editors:
Alimena J. A search for long-lived particles that stop in the CMS
detector and decay to muons. [Doctoral Dissertation]. Brown University; 2016. Available from: https://repository.library.brown.edu/studio/item/bdr:674170/
4.
Pangilinan, Monica O.
Top Quark Produced Through the Electroweak Force: Discovery
Using the Matrix Element Analysis and Search for Heavy Gauge Bosons
Using Boosted Decision Trees.
Degree: PhD, Physics, 2010, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:11370/
► The top quark produced through the electroweak channel provides a direct measurement of the V_tb element in the CKM matrix which can be viewed as…
(more)
▼ The top quark produced through the electroweak channel
provides a direct measurement of the V_tb element in the CKM matrix
which can be viewed as a transition rate of a top quark to a bottom
quark. This production channel of top quark is also sensitive to
different theories beyond the Standard Model such as heavy charged
gauged bosons termed W'.This thesis measures the cross section of
the electroweak produced top quark using a technique based on using
the matrix elements of the processes under consideration. The
technique is applied to 2.3 fb^-1 of data from the DZero detector.
From a comparison of the matrix element discriminants between data
and the signal and background model using Bayesian statistics, we
measure the cross section of the top quark produced through the
electroweak mechanism: σ (ppbar→tb + X, tqb + X) = 4.30 +0.98 -1.20
pb.The measured result corresponds to a 4.9σ Gaussian-equivalent
significance. By combining this analysis with other analyses based
on the Bayesian Neural Network (BNN) and Boosted Decision Tree
(BDT) method, the measured cross section is 3.94 ± 0.88 pb with a
significance of 5.0σ, resulting in the discovery of electroweak
produced top quarks. Using this measured cross section and
constraining |V_tb| < 1, the 95% confidence level (C.L.) lower
limit is |V_tb| > 0.78.Additionally, a search is made for the
production of W' using the same samples from the electroweak
produced top quark. An analysis based on the BDT method is used to
separate the signal from expected backgrounds. No significant
excess is found and 95% C.L. upper limits on the production cross
section are set for W' with masses within 600 - 950 GeV. For four
general models of W' boson production using decay channel W' ->
t bbar, the lower mass limits are the following: M(W'L with SM
couplings) > 840 GeV; M(W'R) > 880 GeV or 890 GeV if the
right-handed neutrino is lighter or heavier than W'R; and M(W'L+R)
> 915 GeV.
Advisors/Committee Members: Narain, Meenakshi (Director), Volovich, Anastasia (Reader), Cutts, David (Reader).
Subjects/Keywords: Electroweak Top Quark
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Manager
APA (6th Edition):
Pangilinan, M. O. (2010). Top Quark Produced Through the Electroweak Force: Discovery
Using the Matrix Element Analysis and Search for Heavy Gauge Bosons
Using Boosted Decision Trees. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:11370/
Chicago Manual of Style (16th Edition):
Pangilinan, Monica O. “Top Quark Produced Through the Electroweak Force: Discovery
Using the Matrix Element Analysis and Search for Heavy Gauge Bosons
Using Boosted Decision Trees.” 2010. Doctoral Dissertation, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:11370/.
MLA Handbook (7th Edition):
Pangilinan, Monica O. “Top Quark Produced Through the Electroweak Force: Discovery
Using the Matrix Element Analysis and Search for Heavy Gauge Bosons
Using Boosted Decision Trees.” 2010. Web. 01 Mar 2021.
Vancouver:
Pangilinan MO. Top Quark Produced Through the Electroweak Force: Discovery
Using the Matrix Element Analysis and Search for Heavy Gauge Bosons
Using Boosted Decision Trees. [Internet] [Doctoral dissertation]. Brown University; 2010. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:11370/.
Council of Science Editors:
Pangilinan MO. Top Quark Produced Through the Electroweak Force: Discovery
Using the Matrix Element Analysis and Search for Heavy Gauge Bosons
Using Boosted Decision Trees. [Doctoral Dissertation]. Brown University; 2010. Available from: https://repository.library.brown.edu/studio/item/bdr:11370/
5.
Avetisyan, Aram.
Measurement of the Top Quark Mass in the Dilepton Channel at
the CMS Experiment.
Degree: PhD, Physics, 2012, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:297707/
► The top quark is the heaviest of the six observed quarks in the Standard Model (SM). Its mass is more than an order of magnitude…
(more)
▼ The top quark is the heaviest of the six observed
quarks in the Standard Model (SM). Its mass is more than an order
of magnitude greater than any other SM fermion, and hence a precise
measurement of this mass provides constraints on the Higgs boson
and many other hypothetical particles. In this analysis, we measure
the mass of the top quark using the 36 pb-1 of data collected by
the CMS experiment from the collisions of the LHC at √s = 7 TeV
center-of-mass energy during the year 2010.
At the LHC, top-antitop quark pairs are expected to be
produced predominantly through gluon fusion and decay almost
exclusively to two W bosons and a bottom-antibottom quark pair. We
consider a W boson decay leptonic if it results in a muon or an
electron and label the decay channel based on the number of
leptonic W decays. Here, we report on the measurement of the mass
of the top quark in the dilepton channel.
The dilepton final state consists of two jets originating
from the bottom quarks, two charged leptons and two neutrinos. The
latter are not visible to our detector, which results in six
unknown parameters. Five of these can be solved for using
constraints arising from transverse momentum conservation, the mass
of the W boson and the equality of masses of the top and antitop
quarks. To deal with the under-constrained system, we use the
Analytical Matrix Weighting Technique. This method iterates over
many values of the top quark mass and analytically solves the
system using the top quark mass as the missing constraint. Each
value of the mass is given a weight based on the kinematics of top
quark production and decay. The mass estimator for each event is
the value with the highest weight and the mass of the top quark is
extracted from these estimators by performing a maximum likelihood
fit to simulated templates constructed for various masses. The
measured value of the top quark mass from this analysis is mt =
175.8 ± 4.9 (stat) ± 4.5 (syst) GeV/c2.
Advisors/Committee Members: Narain, Meenakshi (Director), Cutts, David (Reader), Guralnik, Gerald (Reader).
Subjects/Keywords: CMS
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Manager
APA (6th Edition):
Avetisyan, A. (2012). Measurement of the Top Quark Mass in the Dilepton Channel at
the CMS Experiment. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:297707/
Chicago Manual of Style (16th Edition):
Avetisyan, Aram. “Measurement of the Top Quark Mass in the Dilepton Channel at
the CMS Experiment.” 2012. Doctoral Dissertation, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:297707/.
MLA Handbook (7th Edition):
Avetisyan, Aram. “Measurement of the Top Quark Mass in the Dilepton Channel at
the CMS Experiment.” 2012. Web. 01 Mar 2021.
Vancouver:
Avetisyan A. Measurement of the Top Quark Mass in the Dilepton Channel at
the CMS Experiment. [Internet] [Doctoral dissertation]. Brown University; 2012. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:297707/.
Council of Science Editors:
Avetisyan A. Measurement of the Top Quark Mass in the Dilepton Channel at
the CMS Experiment. [Doctoral Dissertation]. Brown University; 2012. Available from: https://repository.library.brown.edu/studio/item/bdr:297707/
6.
Segala, Michael A.
Search for a Higgs Boson Produced in Association with a W
Boson at the LHC.
Degree: PhD, Physics, 2013, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:320593/
► The Standard Model (SM) is the most successful theory of particle physics to date. It has been experimentally verified over the past 40 years as…
(more)
▼ The Standard Model (SM) is the most successful theory
of particle physics to date. It has been experimentally verified
over the past 40 years as the various properties of the SM have
been measured and the particles it predicts have been detected. The
only particle yet to be experimentally confirmed is the SM Higgs
boson. However, recent observations at the Large Hadron Collider
(LHC) give hints of a new scalar boson which is consistent with the
SM Higgs boson.
This thesis presents two searches for the SM Higgs boson at
the LHC using data collected by the CMS detector. In 2011, the
search was performed using 5 fb-1 of data at a 7 TeV center of mass
energy, and in 2012, using 18.3 fb-1 of data at a 8 TeV center of
mass energy. In both analyses, the SM Higgs boson was produced in
association with a W boson, where the Higgs boson then decays into
two b-quarks and the W boson decays into a hadronic tau lepton and
a neutrino. Upper limits, at the 95% confidence level, on the WH
production cross section times the branching ratio of the Higgs
boson decaying into two b-quarks, with respect to the expectations
for a SM Higgs boson, are derived for a Higgs boson in the mass
range 110-150 GeV. At a SM Higgs boson mass of 125 GeV, the
observed limit is 6.4 and the expected limit is 7.7 times the SM
prediction. In both analyses, no excess of events is observed above
the expected background, which is consistent with the expectation
from the production of the SM Higgs boson.
Advisors/Committee Members: Narain, Meenakshi (Director), Cutts, David (Reader), Lowe, David (Reader).
Subjects/Keywords: LHC; CMS; Higgs Boson
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Export
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APA (6th Edition):
Segala, M. A. (2013). Search for a Higgs Boson Produced in Association with a W
Boson at the LHC. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:320593/
Chicago Manual of Style (16th Edition):
Segala, Michael A. “Search for a Higgs Boson Produced in Association with a W
Boson at the LHC.” 2013. Doctoral Dissertation, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:320593/.
MLA Handbook (7th Edition):
Segala, Michael A. “Search for a Higgs Boson Produced in Association with a W
Boson at the LHC.” 2013. Web. 01 Mar 2021.
Vancouver:
Segala MA. Search for a Higgs Boson Produced in Association with a W
Boson at the LHC. [Internet] [Doctoral dissertation]. Brown University; 2013. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:320593/.
Council of Science Editors:
Segala MA. Search for a Higgs Boson Produced in Association with a W
Boson at the LHC. [Doctoral Dissertation]. Brown University; 2013. Available from: https://repository.library.brown.edu/studio/item/bdr:320593/
7.
Demiragli, Zeynep.
Search for new physics in final states with low transverse
energy photon and missing transverse energy in proton-proton
collisions at 8 TeV.
Degree: PhD, Physics, 2015, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:419409/
► With the recent discovery of the Higgs boson at the Large Hadron Collider (LHC), the next set of goals for the Compact Muon Solenoid (CMS)…
(more)
▼ With the recent discovery of the Higgs boson at the
Large Hadron Collider (LHC), the next set of goals for the Compact
Muon Solenoid (CMS) experiment includes characterizing the newly
discovered particle and probing for new physics beyond the Standard
Model. Results from a search for new physics in the final state
with a low transverse energy photon and missing transverse energy,
using a data set corresponding to an integrated luminosity of
7.3/fb collected in proton-proton collisions at 8 TeV with the CMS
detector is presented. Due to the large background rate for this
final state, a novel strategy was used to collect this dataset from
August through December of 2012. Such final state can arise from
models involving dark matter production or exotic decays of the
Higgs boson in low-scale supersymmetry breaking scenarios. In the
absence of deviations from the Standard Model predictions, limits
are set on the probability of an exotic decay of the Higgs boson.
The phase space consisting of a photon with a transverse energy of
at least 45 GeV and significant missing transverse energy was
further examined in a model independent way by varying the
selection requirements on the missing transverse energy and the
transverse mass of the system. Upper limits at the 95% confidence
level on production cross section of possible processes resulting
in this final state were set. Additional and complementary results
from a search for new physics in the final states containing a
high-energy photon and missing transverse energy are also
presented, using the data set corresponding to an integrated
luminosity of 19.6/fb collected in proton-proton collisions at 8
TeV. In the absence of any significant deviation from the Standard
Model predictions, improved limits are set on dark matter
production and on the parameters of a model with large extra
dimensions. Upper limits at a 95% confidence level on the
production cross section of possible processes resulting in the
final state with the photon transverse momentum greater than 145
GeV and missing transverse energy greater than 140 GeV were
set.
Advisors/Committee Members: Landsberg, Greg (Director), Cutts, David (Reader), Volovich, Anastasia (Reader).
Subjects/Keywords: particle physics
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Demiragli, Z. (2015). Search for new physics in final states with low transverse
energy photon and missing transverse energy in proton-proton
collisions at 8 TeV. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:419409/
Chicago Manual of Style (16th Edition):
Demiragli, Zeynep. “Search for new physics in final states with low transverse
energy photon and missing transverse energy in proton-proton
collisions at 8 TeV.” 2015. Doctoral Dissertation, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:419409/.
MLA Handbook (7th Edition):
Demiragli, Zeynep. “Search for new physics in final states with low transverse
energy photon and missing transverse energy in proton-proton
collisions at 8 TeV.” 2015. Web. 01 Mar 2021.
Vancouver:
Demiragli Z. Search for new physics in final states with low transverse
energy photon and missing transverse energy in proton-proton
collisions at 8 TeV. [Internet] [Doctoral dissertation]. Brown University; 2015. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:419409/.
Council of Science Editors:
Demiragli Z. Search for new physics in final states with low transverse
energy photon and missing transverse energy in proton-proton
collisions at 8 TeV. [Doctoral Dissertation]. Brown University; 2015. Available from: https://repository.library.brown.edu/studio/item/bdr:419409/
8.
Bhattacharya, Saptaparna.
Search for SUperSYmmetry (SUSY) in Opposite Sign (OS)
Dilepton Final States with Parked Data Collected at $\sqrt s$ = 8
TeV Using the CMS Detector.
Degree: PhD, Physics, 2015, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:674118/
► The Large Hadron Collider (LHC) has had a very successful data-taking phase with Run 1. After the discovery of the Higgs, confirming the predictions of…
(more)
▼ The Large Hadron Collider (LHC) has had a very
successful data-taking phase with Run 1. After the discovery of the
Higgs, confirming the predictions of the Standard Model (SM), the
focus is on finding new physics, especially in the context of
supersymmetry (SUSY). One of the potential hiding places of natural
SUSY is in models with compressed spectra, that is, models where
the mass difference between the parent SUSY particle and the
Lightest Supersymmetric Particle (LSP) is small. Such signals are
characterized by low transverse momentum (p{
T}) objects, low
hadronic activity and missing transverse energy (MET). In this
analysis, we focus on di-lepton final states, specifically in the
low p{
T} regime. We use 7.4 fb
-1 of parked data collected
at √{s} = 8 TeV. The analysis is enabled by the use of
triggers that place no restrictions on the di-lepton p{
T},
instead relying on methods like Initial State Radiation (ISR)
tagging by triggering on a high p{
T} photon, to reduce the
trigger rate. The final state we are interested in consists of a
high p{
T} photon and two oppositely charged leptons. Since no
statistically significant excess of events consistent with the
presence of supersymmetric particles was found, we compute
exclusion limits at a 95% confidence level for the cross section
of stop pair production in association with a photon. We also show
results for model independent limits in this channel.
Advisors/Committee Members: Landsberg, Greg (Director), Cutts, David (Reader), Lowe, David (Reader).
Subjects/Keywords: Large Hadron Collider
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APA (6th Edition):
Bhattacharya, S. (2015). Search for SUperSYmmetry (SUSY) in Opposite Sign (OS)
Dilepton Final States with Parked Data Collected at $\sqrt s$ = 8
TeV Using the CMS Detector. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:674118/
Chicago Manual of Style (16th Edition):
Bhattacharya, Saptaparna. “Search for SUperSYmmetry (SUSY) in Opposite Sign (OS)
Dilepton Final States with Parked Data Collected at $\sqrt s$ = 8
TeV Using the CMS Detector.” 2015. Doctoral Dissertation, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:674118/.
MLA Handbook (7th Edition):
Bhattacharya, Saptaparna. “Search for SUperSYmmetry (SUSY) in Opposite Sign (OS)
Dilepton Final States with Parked Data Collected at $\sqrt s$ = 8
TeV Using the CMS Detector.” 2015. Web. 01 Mar 2021.
Vancouver:
Bhattacharya S. Search for SUperSYmmetry (SUSY) in Opposite Sign (OS)
Dilepton Final States with Parked Data Collected at $\sqrt s$ = 8
TeV Using the CMS Detector. [Internet] [Doctoral dissertation]. Brown University; 2015. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:674118/.
Council of Science Editors:
Bhattacharya S. Search for SUperSYmmetry (SUSY) in Opposite Sign (OS)
Dilepton Final States with Parked Data Collected at $\sqrt s$ = 8
TeV Using the CMS Detector. [Doctoral Dissertation]. Brown University; 2015. Available from: https://repository.library.brown.edu/studio/item/bdr:674118/
9.
Malling, David Charles.
Measurement and Analysis of WIMP Detection Backgrounds, and
Characteri- zation and Performance of the Large Underground Xenon
Dark Matter Search Experiment.
Degree: PhD, Physics, 2014, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:386168/
► The dominant component of matter in the universe, referred to as dark matter, cannot be explained by the standard model of particle physics. A leading…
(more)
▼ The dominant component of matter in the universe,
referred to as dark matter, cannot be explained by the standard
model of particle physics. A leading candidate for dark matter is
the weakly interacting massive particle (WIMP). The WIMP theory is
well motivated by several extensions of the standard model, and has
been tested directly in the laboratory over the last 30 years. The
Large Underground Xenon (LUX) experiment seeks to identify the
signatures of WIMP interactions with baryonic matter. LUX measures
particle interactions at the keV level by the detection of
single-photon signals in a 250 kg Xe target mass. The LUX detector
inner fiducial region is the lowest measured background particle
detector in the world at keV energies, with background rates at the
level of 1E-3 counts/keV/kg/day. Low background rates are essential
for identifying WIMP interactions in the detector, which occur with
frequencies <1/kg/(5 years). LUX completed its first
low-background science run at the Sanford Underground Research
Facility in August 2013. WIMP search results are reported from an
85 live day analysis. The experiment places the tightest constraint
on WIMP spin-independent interaction cross-sections to date.
Results from LUX also exclude several potential dark matter signal
claims from other direct detection experiments, for WIMP masses in
the range 6-15 GeV. The LUX result is the product of low detector
background rates and high photon signal collection efficiency.
Analysis of the first WIMP search data has provided direct
characterization of low-energy backgrounds in LUX. Measured
background rates were found to be in agreement with expectations
based on models of detector material radioactivity. The data also
provides the first measurements of intrinsic radioactive
contaminants in the detector, including short-lived cosmogenic Xe
radioisotopes. I will describe the LUX background model, detailing
work which was used in the design and early performance projections
of the LUX detector, as well as background measurements which
constrain and support the model.
Advisors/Committee Members: Gaitskell, Richard (Director), Savvas, Koushiappas (Reader), Cutts, David (Reader).
Subjects/Keywords: Dark matter
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Chicago ·
MLA ·
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CSE |
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APA (6th Edition):
Malling, D. C. (2014). Measurement and Analysis of WIMP Detection Backgrounds, and
Characteri- zation and Performance of the Large Underground Xenon
Dark Matter Search Experiment. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:386168/
Chicago Manual of Style (16th Edition):
Malling, David Charles. “Measurement and Analysis of WIMP Detection Backgrounds, and
Characteri- zation and Performance of the Large Underground Xenon
Dark Matter Search Experiment.” 2014. Doctoral Dissertation, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:386168/.
MLA Handbook (7th Edition):
Malling, David Charles. “Measurement and Analysis of WIMP Detection Backgrounds, and
Characteri- zation and Performance of the Large Underground Xenon
Dark Matter Search Experiment.” 2014. Web. 01 Mar 2021.
Vancouver:
Malling DC. Measurement and Analysis of WIMP Detection Backgrounds, and
Characteri- zation and Performance of the Large Underground Xenon
Dark Matter Search Experiment. [Internet] [Doctoral dissertation]. Brown University; 2014. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:386168/.
Council of Science Editors:
Malling DC. Measurement and Analysis of WIMP Detection Backgrounds, and
Characteri- zation and Performance of the Large Underground Xenon
Dark Matter Search Experiment. [Doctoral Dissertation]. Brown University; 2014. Available from: https://repository.library.brown.edu/studio/item/bdr:386168/
10.
Kelly, Wessyl R.
Measuring Weak Gravitational Lensing in General Purpose
Imaging Surveys.
Degree: PhD, Physics, 2010, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:11025/
► The quantities and properties of the dark constituents of the universe reveal much about the past and future development of the cosmos. It is thought…
(more)
▼ The quantities and properties of the dark constituents
of the universe reveal much about the past and future development
of the cosmos. It is thought that dark matter provides 85% of the
mass in the universe, and that it is certainly the dominant
component in large structures from galaxies to superclusters. Dark
matter density, clustering, and quantity have repercussions for the
universe's geometry, its past and future evolution (and ultimate
fate), as well as for the more specific question of how structure
has formed. Weak gravitational lensing is one of the only tools
available to measure dark matter densities directly; most other
methods measure observables that have a poorly known, and often
debated, relationship to the dark mass. Although its direct
sensitivity to mass distributions provides an obvious advantage for
weak lensing, because it is a statistical measurement whose signal
strength typically has been of the same order of magnitude as
systematic and random noise, until recently it has been difficult
to adequately and convincingly control for these. For this reason,
weak lensing data collection has normally been specifically
designed to mitigate these factors. The unique requirements for
optimal weak lensing observations combined with limited telescope
time have meant that there are relatively few datasets that have
been used for weak lensing. There is a huge body of past and future
data designed for other types of studies for which weak lensing
analysis has been considered inappropriate. However, weak
gravitational lensing techniques have matured. In this work for the
first time, we have applied weak lensing methods to a dataset that
was not engineered for weak lensing studies. The NOAO Deep
Wide-Field Survey (NDWFS) optical dataset includes almost 9 square
degrees over 27 subfields with a range of best seeing from 0.66" to
1.20" in three different filters (I, R, and Bw). We use this
dataset to show that weak lensing analysis may now be successfully
applied to data formerly not considered suitable. We find that
detections of cluster-sized mass densities from this dataset
perform comparably to detections from previous surveys. We
correlate our detections with the Chandra XBoötes results for
extended sources.
Advisors/Committee Members: Dell'Antonio, Ian (Director), Cutts, David (Reader), Tucker, Gregory (Reader).
Subjects/Keywords: weak gravitational lensing
Record Details
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Record Details
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Cite
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kelly, W. R. (2010). Measuring Weak Gravitational Lensing in General Purpose
Imaging Surveys. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:11025/
Chicago Manual of Style (16th Edition):
Kelly, Wessyl R. “Measuring Weak Gravitational Lensing in General Purpose
Imaging Surveys.” 2010. Doctoral Dissertation, Brown University. Accessed March 01, 2021.
https://repository.library.brown.edu/studio/item/bdr:11025/.
MLA Handbook (7th Edition):
Kelly, Wessyl R. “Measuring Weak Gravitational Lensing in General Purpose
Imaging Surveys.” 2010. Web. 01 Mar 2021.
Vancouver:
Kelly WR. Measuring Weak Gravitational Lensing in General Purpose
Imaging Surveys. [Internet] [Doctoral dissertation]. Brown University; 2010. [cited 2021 Mar 01].
Available from: https://repository.library.brown.edu/studio/item/bdr:11025/.
Council of Science Editors:
Kelly WR. Measuring Weak Gravitational Lensing in General Purpose
Imaging Surveys. [Doctoral Dissertation]. Brown University; 2010. Available from: https://repository.library.brown.edu/studio/item/bdr:11025/
. 
Open Access Theses and Dissertations