15 research outputs found
Observation and Mass Measurement of the Baryon
We report the observation and measurement of the mass of the bottom, strange
baryon through the decay chain , where
, , and .
Evidence for observation is based on a signal whose probability of arising from
the estimated background is 6.6 x 10^{-15}, or 7.7 Gaussian standard
deviations. The mass is measured to be (stat.) (syst.) MeV/.Comment: Minor text changes for the second version. Accepted by Phys. Rev.
Let
Polarizations of J/psi and psi(2S) Mesons Produced in ppbar Collisions at 1.96 TeV
We have measured the polarizations of \jpsi and \psiprime mesons as
functions of their transverse momentum \pt when they are produced promptly in
the rapidity range with \pt \geq 5 \pgev. The analysis is performed
using a data sample with an integrated luminosity of about 800 \ipb collected
by the CDF II detector. For both vector mesons, we find that the polarizations
become increasingly longitudinal as \pt increases from 5 to 30 \pgev. These
results are compared to the predictions of nonrelativistic quantum
chromodynamics and other contemporary models. The effective polarizations of
\jpsi and \psiprime mesons from -hadron decays are also reported.Comment: 8 pages, 7 figures, published in Physical Review Letter
Precise measurement of the top quark mass in the lepton+jets topology at CDF II
We present a measurement of the mass of the top quark from proton-antiproton
collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron.
We analyze events from the single lepton plus jets final state (). The top quark mass is extracted
using a direct calculation of the probability density that each event
corresponds to the final state. The probability is a function of both
the mass of the top quark and the energy scale of the calorimeter jets, which
is constrained {\it in situ} by the hadronic boson mass. Using 167 events
observed in 955 pb of integrated luminosity, we achieve the single
most precise measurement of the top quark mass, 170.8 2.2 (stat.)
1.4 (syst.) GeV/.Comment: accepted by Phys. Rev. Let
First Measurement of the W Boson Mass in Run II of the Tevatron
We present a measurement of the W boson mass using 200/pb of data collected
in pbar p collisions at sqrt(s) = 1.96 TeV by the CDF II detector at Run II of
the Fermilab Tevatron. With a sample of 63964 W -> e nu candidates and 51128 W
-> mu nu candidates, we measure M_W = (80413 +- 34 (stat) +- 34 (syst) = 80413
+- 48) MeV/c^2. This is the most precise single measurement of the W boson mass
to date.Comment: published version in PR
Search for New Particles Leading to Z+jets Final States in Collisions at TeV
We present the results of a search for new particles that lead to a \Z boson
plus jets in collisions at TeV using the Collider
Detector at Fermilab (CDF II). A data sample with a luminosity of 1.06 \ifb\
collected using \Z boson decays to and is used. We describe a
completely data-based method to predict the dominant background from
standard-model \Z+jet events. This method can be similarly applied to other
analyses requiring background predictions in multi-jet environments, as shown
when validating the method by predicting the background from +jets in \ttbar
production. No significant excess above the background prediction is observed,
and a limit is set using a fourth generation quark model to quantify the
acceptance. Assuming and using a leading-order
calculation of the cross section, quark masses below 268 \gev/c^2
are excluded at 95% confidence level.Comment: To be submitted to PR
Event reconstruction for KM3NeT/ORCA using convolutional neural networks
The authors acknowledge the financial support of the funding agencies: Agence Nationale de la Recherche (contract ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Paris Ile-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, FR-18-1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Universita e della Ricerca (MUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education, Scientific Research and Professional Training, Morocco; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider (MCIU), Junta de Andalucia (ref. SOMM17/6104/UGR), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119) and GenT (ref. CIDEGENT/2018/034) programs, La Caixa Foundation (ref. LCF/BQ/IN17/11620019), EU: MSC program (ref. 713673), Spain.The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino detector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower- or track-like, and the main background processes associated with the detection of atmospheric neutrinos are recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance improvements with respect to classical approaches.French National Research Agency (ANR)
ANR-15-CE31-0020Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund)European Union (EU)Institut Universitaire de France (IUF)LabEx UnivEarthS
ANR-10-LABX-0023
ANR-18-IDEX-0001Shota Rustaveli National Science Foundation of Georgia
FR-18-1268German Research Foundation (DFG)Greek Ministry of Development-GSRTIstituto Nazionale di Fisica Nucleare (INFN)Ministry of Education, Universities and Research (MIUR)
Research Projects of National Relevance (PRIN)Ministry of Higher Education, Scientific Research and Professional Training, MoroccoNetherlands Organization for Scientific Research (NWO)National Science Centre, Poland
2015/18/E/ST2/00758National Authority for Scientific Research (ANCS), RomaniaMinisterio de Ciencia, Innovacion, Investigacion y Universidades
PGC2018-096663-B-C41
A-C42
B-C43
B-C44Severo Ochoa Centre of ExcellenceJunta de Andalucia
SOMM17/6104/UGRGeneralitat Valenciana: Grisolia
GRISOLIA/2018/119
CIDEGENT/2018/034La Caixa Foundation
LCF/BQ/IN17/11620019EU: MSC program
71367
Measurement of the ttbar Production Cross Section in ppbar collisions at sqrt{s} = 1.96 TeV using Lepton+Jets Events with Jet Probability b-tagging
We present a measurement of the ttbar production cross section using events
with one charged lepton and jets from ppbar collisions at a center-of-mass
energy of 1.96 TeV. A b-tagging algorithm based on the probability of displaced
tracks coming from the event interaction vertex is applied to identify b quarks
from top decay. Using 318 pb^{-1} of data collected with the CDF II detector,
we measure the ttbar production cross section in events with at least one
restrictive (tight) b-tagged jet and obtain 8.9 +1.0-1.0 (stat.) +1.1-1.0
(syst.) pb. The cross section value assumes a top quark mass of m_{t}=178 GeV
in the acceptance corrections. The dependence of the cross section on m_t is
presented in the paper. This result is consistent with other CDF measurements
of the ttbar cross section using different samples and analysis techniques, and
has similar systematic uncertainties. We have also performed consistency checks
by using the b-tagging probability function to vary the signal to background
ratio and also using events that have at least two b-tagged jets.Comment: 45 pages, 27 figures, submitted to Physical Review
Success factors of equestrian tourism: evidence from Germany
Although Germany clearly lies at the top of international ranks in both equestrian sports and horse breeding (FN, 2012), research on success factors of equestrian tourism is still lacking. Against this background, this study presents the results of the online-survey focused on perception of the own business of 107 owners of horse-riding farms. The findings of regression analysis conducted both in the whole samples (n=107) as well in the sub-sample (n=34) show that different factors have an influence on business success such as customer satisfaction in the whole sample and control practices and positive image in the sub-sample. Accordingly, managerial implications are discussed
Palaeozoic amalgamation of Central Europe: new results from recent geological and geophysical investigations
Multidisciplinary studies of geotransects across the North European Plain and Southern North Sea, and geological reexamination of the Variscides of the North Bohemian Massif, permit a new 3-D reassessment of the relationships between the principal crustal blocks abutting Baltica along the Trans-European Suture Zone (TESZ). Accretion was in three stages: Cambrian accretion of the Bruno-Silesian, Lysogory and Malopolska terranes; end-Ordovician/early Silurian accretion of Avalonia; and early Carboniferous accretion of the Armorican Terrane Assemblage (ATA). Palaeozoic plume-influenced metabasite geochemistry in the Bohemian Massif explains the progressive rifting away of peri-Gondwanan crustal blocks before their accretion to Baltica. Geophysical data, faunal and provenance information from boreholes, and dated small inliers and cores confirm that Avalonian crust extends beyond the Anglo-Brabant Deformation Belt eastwards to northwest Poland. The location and dip of reflectors along the TESZ and beneath the North European Plain suggest that Avalonian crust overrode the Baltica passive margin, marked by a high-velocity lower crustal layer, on shallowly southwest-dipping thrust planes forming the Heligoland-Pomerania Deformation Belt. The "Variscan orocline" of southwest Poland masks two junctions between the Armorican Terrane Assemblage (ATA) and previously accreted crustal blocks. To the easr is a dextrally transpressive contact with the Bruno-Silesian and Malopolska blocks, accreted in the Cambrian , while to the north is a thrust contact with eastemmost Avalonia deeply buried beneath younger sedimentary cover. In the northeast Bohemian and Rhenohercynian Massifs Devonian "early Variscide" deformation dominated by WNW and NW-directed thrusting, records closure of Ordovician-Devonian seaways between "islands" of the ATA and Avalonia