Results of the Model Unspecific Search in CMS (MUSiC), using proton–proton collision data recorded at the LHC at a centre-of-mass energy of 13
TeV
, corresponding to an integrated luminosity of 35.9
...fb
-
1
, are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
ABSTRACTVascular hypertrophy, a feature of experimental and human diabetes, has been implicated in the pathogenesis of the microvascular and macrovascular complications of the disease. In the present ...study, we sought to examine the role of endogenous endothelin and its relation to vascular growth factors in the mediation of vascular hypertrophy in experimental diabetes and to examine the contribution of mast cells to this process. Vessel morphology, endothelin, growth factor gene expression, and matrix deposition were studied in the mesenteric arteries of control and streptozotocin-induced diabetic Sprague-Dawley rats treated with or without the dual endothelinA/B receptor antagonist bosentan (100 mg · kg · d) during a 3-week period. Compared with control animals, diabetic animals had significant increases in vessel weight, wall-to-lumen ratio, mast cell infiltration, extracellular matrix deposition, and gene expression of epidermal growth factor (EGF) and transforming growth factor-β1. In diabetic, but not control, vessels, not only were EGF mRNA and endothelin present in endothelial cells, but also their expression was observed in adventitial mast cells. Immunoreactive endothelin was present in the media of mesenteric vessels of diabetic, but not control, animals. Bosentan treatment significantly reduced mesenteric weight, wall-to-lumen ratio, mast cell infiltration, matrix deposition, and EGF mRNA but did not prevent the overexpression of transforming growth factor-β1 mRNA in diabetic rats. These findings suggest that endogenous endothelin and EGF may play a role in diabetes-induced vascular hypertrophy and that mast cells may be pathogenetically involved in this process.
A search is presented for a heavy vector resonance decaying into a
Z
boson and the standard model Higgs boson, where the
Z
boson is identified through its leptonic decays to electrons, muons, or ...neutrinos, and the Higgs boson is identified through its hadronic decays. The search is performed in a Lorentz-boosted regime and is based on data collected from 2016 to 2018 at the CERN LHC, corresponding to an integrated luminosity of 137
fb
-
1
. Upper limits are derived on the production of a narrow heavy resonance
Z
′
, and a mass below 3.5 and 3.7
Te
is excluded at 95% confidence level in models where the heavy vector boson couples predominantly to fermions and to bosons, respectively. These are the most stringent limits placed on the Heavy Vector Triplet
Z
′
model to date. If the heavy vector boson couples exclusively to standard model bosons, upper limits on the product of the cross section and branching fraction are set between 23 and 0.3
fb
for a
Z
′
mass between 0.8 and 4.6
Te
, respectively. This is the first limit set on a heavy vector boson coupling exclusively to standard model bosons in its production and decay.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The International Atomic Energy Agency (IAEA) is responsible for verifying the mass of elemental uranium in various forms (powders, pellets, scrap) as part of inspections at nuclear fuel fabrication ...facilities. Current methods require in-field dissolution chemistry, which is time consuming and imposes operational challenges. Pacific Northwest National Laboratory (PNNL) is developing a prototype spectral x-ray radiography (SpecX) nondestructive assay system for noninvasive material mass quantification of uranium-bearing powders. The SpecX system uses a custom material estimation algorithm, which requires a high-fidelity pixel-by-pixel detector response model for accurate quantification. We performed a detailed characterization and built a model of a High-Energy X-ray Imaging Technology (HEXITEC) CdTe pixelated spectral detector. Here we present the detector characterization which led to that model, including a determination of the pixel-wise energy calibration, the detection efficiency, the detector uniformity, the detector stability, and a comparison of methods to remove charge-shared events.
A
bstract
A measurement of electroweak-induced production of Wγ and two jets is performed, where the W boson decays leptonically. The data used in the analysis correspond to an integrated luminosity ...of 19.7 fb
−1
collected by the CMS experiment in
s
=
8
TeV proton-proton collisions produced at the LHC. Candidate events are selected with exactly one muon or electron, missing transverse momentum, one photon, and two jets with large rapidity separation. An excess over the hypothesis of the standard model without electroweak production of Wγ with two jets is observed with a significance of 2.7 standard deviations. The cross section measured in the fiducial region is 10
.
8 ± 4
.
1(stat) ± 3
.
4(syst) ± 0
.
3(lumi) fb, which is consistent with the standard model electroweak prediction. The total cross section for Wγ in association with two jets in the same fiducial region is measured to be 23
.
2 ± 4
.
3(stat) ± 1
.
7(syst) ± 0
.
6(lumi) fb, which is consistent with the standard model prediction from the combination of electroweak and quantum chromodynamics-induced processes. No deviations are observed from the standard model predictions and experimental limits on anomalous quartic gauge couplings
f
M
,0−7
/
Λ
4
,
f
T
,0−2
/
Λ
4
, and
f
T
,5−7
/
Λ
4
are set at 95% confidence level.
A
bstract
A search is performed for a pseudoscalar Higgs boson, A, decaying into a 125 GeV Higgs boson h and a Z boson. The h boson is specifically targeted in its decay into a pair of tau leptons, ...while the Z boson decays into a pair of electrons or muons. A data sample of proton-proton collisions collected by the CMS experiment at the LHC at
s
= 13 TeV is used, corresponding to an integrated luminosity of 35.9 fb
−
1
. No excess above the standard model background expectations is observed in data. A model-independent upper limit is set on the product of the gluon fusion production cross section for the A boson and the branching fraction to Zh
→ ℓℓττ
. The observed upper limit at 95% confidence level ranges from 27 to 5 fb for A boson masses from 220 to 400 GeV, respectively. The results are used to constrain the extended Higgs sector parameters for two benchmark scenarios of the minimal supersymmetric standard model.
A
bstract
A search has been performed for heavy resonances decaying to ZZ or ZW in 2
ℓ
2q final states, with two charged leptons (
ℓ
= e
, μ
) produced by the decay of a Z boson, and two quarks ...produced by the decay of a W or Z boson. The analysis is sensitive to resonances with masses in the range from 400 to 4500 GeV. Two categories are defined based on the merged or resolved reconstruction of the hadronically decaying vector boson, optimized for high- and low-mass resonances, respectively. The search is based on data collected during 2016 by the CMS experiment at the LHC in proton-proton collisions with a center-of-mass energy of
s
=
13
TeV, corresponding to an integrated luminosity of 35.9 fb
−1
. No excess is observed in the data above the standard model background expectation. Upper limits on the production cross section of heavy, narrow spin-1 and spin-2 resonances are derived as a function of the resonance mass, and exclusion limits on the production of W
′
bosons and bulk graviton particles are calculated in the framework of the heavy vector triplet model and warped extra dimensions, respectively.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract A search for new physics is performed in multijet events with large missing transverse momentum produced in ...proton-proton collisions at ... = 8 TeV using a data sample corresponding to an integrated luminosity of 19.5 fb^sup -1^ collected with the CMS detector at the LHC. The data sample is divided into three jet multiplicity categories (3-5, 6-7, and greater than or equal to8 jets), and studied further in bins of two variables: the scalar sum of jet transverse momenta and the missing transverse momentum. The observed numbers of events in various categories are consistent with backgrounds expected from standard model processes. Exclusion limits are presented for several simplified supersymmetric models of squark or gluino pair production. Figure not available: see fulltext.
A
bstract
A search for the production of a single top quark in association with a Z boson is presented, both to identify the expected standard model process and to search for flavour-changing neutral ...current interactions. The data sample corresponds to an integrated luminosity of 19.7 fb
−1
recorded by the CMS experiment at the LHC in proton-proton collisions at
s
=
8
TeV. Final states with three leptons (electrons or muons) and at least one jet are investigated. An events yield compatible with tZq standard model production is observed, and the corresponding cross section is measured to be
σ
(pp → tZq →
ℓν
b
ℓ
+
ℓ
−
q) = 10
− 7
+ 8
fb with a significance of 2.4 standard deviations. No presence of flavour-changing neutral current production of tZq is observed. Exclusion limits at 95% confidence level on the branching fractions of a top quark decaying to a Z boson and an up or a charm quark are found to be ℬ(t → Zu) < 0.022% and ℬ(t → Zc) < 0.049%.
A
bstract
Angular distributions of the decay B
+
→
K
∗
(892)
+
μ
+
μ
−
are studied using events collected with the CMS detector in
s
= 8 TeV proton-proton collisions at the LHC, corresponding to an ...integrated luminosity of 20.0 fb
−
1
. The forward-backward asymmetry of the muons and the longitudinal polarization of the K
∗
(892)
+
meson are determined as a function of the square of the dimuon invariant mass. These are the first results from this exclusive decay mode and are in agreement with a standard model prediction.
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