(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in ...proton-proton collision data at a centre-of-mass energy of ... corresponding to an integrated luminosity of 38 pb^sup -1^. Jets are reconstructed with the anti-k ^sub t^ algorithm with distance parameters R=0.4 or R=0.6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta p ^sub T^greater than or equal to20 GeV and pseudorapidities |eta|<4.5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2.5 % in the central calorimeter region (|eta|<0.8) for jets with 60less than or equal top ^sub T^<800 GeV, and is maximally 14 % for p ^sub T^<30 GeV in the most forward region 3.2less than or equal to|eta|<4.5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon p ^sub T^, the sum of the transverse momenta of tracks associated to the jet, or a system of low-p ^sub T^ jets recoiling against a high-p ^sub T^ jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-p ^sub T^ jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Data analysis of an experiment in which photon splitting in atomic fields was observed is presented. The experiment was performed at the tagged photon beam of the ROKK-1M facility at the VEPP-4M ...collider. In the energy region of 120-450 MeV, statistics of 1.6x10(9) photons incident on the BGO target was collected. About 400 candidate photon-splitting events were reconstructed. Within the attained experimental accuracy, the experimental results are consistent with the calculated exact atomic-field cross section. The predictions obtained in the Born approximation differ significantly from the experimental results.
This Letter presents the first search for supersymmetry in final states containing one isolated electron or muon, jets, and missing transverse momentum from √s=7 TeV proton-proton collisions at the ...LHC. The data were recorded by the ATLAS experiment during 2010 and correspond to a total integrated luminosity of 35 pb(-1). No excess above the standard model background expectation is observed. Limits are set on the parameters of the minimal supergravity framework, extending previous limits. Within this framework, for A(0)=0 GeV, tanβ=3, and μ>0 and for equal squark and gluino masses, gluino masses below 700 GeV are excluded at 95% confidence level.
The records of new localities of charophytes from the Yenisey Siberia and confirmations for the ones known before were summarized as a result of study both available herbarium collections and field ...studies during 2007–2021. The twenty species, including one novel genus and five novel species records, 59 new localities (67 % of its total number), 127 new populations (83 % of its total number) were found in this region. In particular, 12 species (incl. 3 novel ones for the region) are known from the Republic of Khakassia, 17 (7) – from the Krasnoyarsk Territory, 12 (7) – from the Tuva Republic. The genus Chara is the most species-rich and frequent in the area of study. The taxonomic rank of C. arcuatifolia sensu Hollerb. et Krassavina is discussed. It seems to be a morphotype of C. globularis having clearly arcuate branchlets. Nitella tenuissima is a novel species record for Asian Russia. The charophyte northernmost locality on the continent was revealed. It belongs to C. virgata collected at Southern Taymyr. The novel locality of circumpolar species Tolypella canadensis, far distant from ones known before from Komi Republic and Republic of Yakutia, was found in this region too. The species occurrence in different ecoregions was estimated. The contemporary presence of some species after long intervals between observations from their first records was confirmed. The persistence of the same species in the same water bodies after a long period was revealed as evidence of stability of their populations, important for species protection. The loss of charophyte localities as a result of construction of large Krasnoyarskoe and Sayano-Shushenskoe water reservoirs is remarkable. The red lists for the regions studied were compiled and some species were suggested for protection. The important charophyte areas enabling protection of some species were revealed.
This Letter reports on a search for narrow high-mass resonances decaying into dilepton final states. The data were recorded by the ATLAS experiment in pp collisions at √s=7 TeV at the Large Hadron ...Collider and correspond to a total integrated luminosity of 1.08 (1.21) fb(-1) in the e(+)e(-) (μ(+)μ(-)) channel. No statistically significant excess above the standard model expectation is observed and upper limits are set at the 95% C.L. on the cross section times branching fraction of Z' resonances and Randall-Sundrum gravitons decaying into dileptons as a function of the resonance mass. A lower mass limit of 1.83 TeV on the sequential standard model Z' boson is set. A Randall-Sundrum graviton with coupling k/M(Pl)=0.1 is excluded at 95% C.L. for masses below 1.63 TeV.
With the establishment and maturation of the experimental programs searching for new physics with sizeable couplings at the LHC, there is an increasing interest in the broader particle and ...astrophysics community for exploring the physics of light and feebly-interacting particles as a paradigm complementary to a New Physics sector at the TeV scale and beyond. FIPs 2020 has been the first workshop fully dedicated to the physics of feebly-interacting particles and was held virtually from 31 August to 4 September 2020. The workshop has gathered together experts from collider, beam dump, fixed target experiments, as well as from astrophysics, axions/ALPs searches, current/future neutrino experiments, and dark matter direct detection communities to discuss progress in experimental searches and underlying theory models for FIPs physics, and to enhance the cross-fertilisation across different fields. FIPs 2020 has been complemented by the topical workshop “Physics Beyond Colliders meets theory”, held at CERN from 7 June to 9 June 2020. This document presents the summary of the talks presented at the workshops and the outcome of the subsequent discussions held immediately after. It aims to provide a clear picture of this blooming field and proposes a few recommendations for the next round of experimental results.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this paper, we consider new quantum mechanisms for selective detection in complex gaseous media which provide the highest possible efficiency of quantum sensors and for the first time analyze ...their nature. On the basis of these quantum mechanisms, the concepts of quantum detection and innovative methods of analysis are developed, which are virtually impossible to implement in the conventional conductive sensors and nanosensors. Examples of original solutions to problems in the field of detection and analysis of human breath using point-contact sensors are considered. A new method of analysis based on detection of metastable quantum states of the "point-contact sensor-breath" system in dynamic mode is proposed. The conductance histogram of dendritic Yanson point contacts recorded for this system is a unique energy signature of breath which allows differentiation between the states of human body. We demonstrate that nanosized Yanson point contacts, which, thanks to their quantum properties, can replace a massive spectrometer, open up wide opportunities for solving complex problems in the field of breath analysis using a new generation of portable high-tech quantum sensor devices.
The KEDR detector Anashin, V. V.; Aulchenko, V. M.; Baldin, E. M. ...
Physics of particles and nuclei,
07/2013, Letnik:
44, Številka:
4
Journal Article
Recenzirano
The KEDR detector is a universal magnetic detector designed for studying the
c
- and
b
-quarks and two-photon physics, and is employed at the VEPP-4M
e
+
e
−
collider. A specific feature of the ...experiment is the measurement of absolute beam energy using two methods: the resonant depolarization and the faster but less precise Compton backscattering of laser photons. This allowed a large series of measurements to be performed, in which the accuracy of determination of such fundamental parameters of particles as mass and total and leptonic widths was improved.
A measurement is presented of the
ϕ
×
BR
(
ϕ
→
K
+
K
-
)
production cross section at
s
= 7 TeV using
p
p
collision data corresponding to an integrated luminosity of 383
μ
b
-
1
, collected with the ...ATLAS experiment at the LHC. Selection of
ϕ
(1020) mesons is based on the identification of charged kaons by their energy loss in the pixel detector. The differential cross section is measured as a function of the transverse momentum,
p
T
,
ϕ
, and rapidity,
y
ϕ
, of the
ϕ
(1020) meson in the fiducial region 500
<
p
T
,
ϕ
<
1200 MeV,
|
y
ϕ
|
<
0.8, kaon
p
T
,
K
>
230 MeV and kaon momentum
p
K
<
800 MeV. The integrated
ϕ
(
1020
)
-meson production cross section in this fiducial range is measured to be
σ
ϕ
×
BR
(
ϕ
→
K
+
K
-
)
= 570
±
8 (stat)
±
66 (syst)
±
20 (lumi)
μ
b
.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The paper contains an analysis of the operational conditions of a quarter-wave power supply in an electric system. Its applicability for the operation in electric mains and electric power ...transportation is shown in the paper.
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