273 research outputs found
Measurement of Hadron and Lepton-Pair Production at 130GeV < \sqrt{s} < 189 GeV at LEP
We report on measurements of e+e- annihilation into hadrons and lepton pairs.
The data have been collected with the L3 detector at LEP at centre-of-mass
energies between 130 and 189 GeV. Using a total integrated luminosity of 243.7
pb^-1, 25864 hadronic and 8573 lepton-pair events are selected for the
measurement of cross sections and leptonic forward-backward asymmetries. The
results are in good agreement with Standard Model predictions
Search for Extra Dimensions in Boson and Fermion Pair Production in e+e- Interactions at LEP
Extra spatial dimensions are proposed by recent theories that postulate the
scale of gravity to be of the same order as the electroweak scale. A sizeable
interaction between gravitons and Standard Model particles is then predicted.
Effects of these new interactions in boson and fermion pair production are
searched for in the data sample collected at centre-of-mass energies above the
Z pole by the L3 detector at LEP. In addition, the direct production of a
graviton associated with a Z boson is investigated. No statistically
significant hints for the existence of these effects are found and lower limits
in excess of 1 TeV are derived on the scale of this new theory of gravity
Measurement of Mass and Width of the W Boson at LEP
We report on measurements of the mass and total decay width of the W boson
with the L3 detector at LEP. W-pair events produced in
interactions between 161 GeV and 183 GeV centre-of-mass energy are selected in
a data sample corresponding to a total luminosity of 76.7 pb. Combining
all final states in W-pair production, the mass and total decay width of the W
boson are determined to be GeV and
GeV, respectively
Measurement of the Spectroscopy of Orbitally Excited B Mesons at LEP
We measure the masses, decay widths and relative production rate of orbitally
excited B mesons using 1.25 million hadronic Z decays recorded by the L3
detector. B-meson candidates are inclusively reconstructed and combined with
charged pions produced at the primary event vertex. An excess of events above
the expected background in the B\pi mass spectrum in the region 5.6-5.8 GeV is
interpreted as resulting from the decay B_u,d^** -> B^(*)\pi, where B_u,d^**
denotes a mixture of l=1 B-meson states containing a u or a d quark. A fit to
the mass spectrum yields the masses and decay widths of the B_1^* and B_2^*
spin states, as well as the branching fraction for the combination of l=1
states. In addition, evidence is presented for the existence of an excited
B-meson state or mixture of states in the region 5.9-6.0 GeV
Search for Heavy Neutral and Charged Leptons in ee Annihilation at = 183 and 189 GeV
A search for unstable neutral and charged heavy leptons as well as for stable
charged heavy leptons is performed at center-of-mass energies = 183
and 189 GeV with the L3 detector at LEP. No evidence for their existence is
found. We exclude neutral heavy leptons which couple to the electron, muon or
tau family, of the Dirac type for masses below 92.4, 93.3 and 83.3 GeV, and of
the Majorana type for masses below 81.8, 84.1 and 73.5 GeV, respectively. We
exclude unstable charged heavy leptons for masses below 93.9 GeV for a wide
range of the associated neutral heavy lepton mass. If the unstable charged
heavy lepton decays to a light neutrino, we exclude masses below 92.4 GeV. The
production of stable charged heavy leptons with mass less than 93.5 GeV is also
excluded
Search for Neutral Higgs Bosons of the Minimal Supersymmetric Standard Model in e+e- Interactions at \sqrt{s} = 189 GeV
A search for the lightest neutral scalar and neutral pseudoscalar Higgs
bosons in the Minimal Supersymmetric Standard Model is performed using 176.4
pb^-1 of integrated luminosity collected by L3 at a center-of-mass energy of
189 GeV. No signal is observed, and the data are consistent with the expected
Standard Model background. Lower limits on the masses of the lightest neutral
scalar and pseudoscalar Higgs bosons are given as a function of tan(beta).
Lower mass limits for tan(beta)>1 are set at the 95% confidence level to be m_h
> 77.1 GeV and m_A > 77.1 GeV
Measurement of an Elongation of the Pion Source in Z Decays
We measure Bose-Einstein correlations between like-sign charged pion pairs in
hadronic Z decays with the L3 detector at LEP. The analysis is performed in
three dimensions in the longitudinal center-of-mass system. The pion source is
found to be elongated along the thrust axis with a ratio of transverse to
longitudinal radius of
Measurement of charm production at central rapidity in proton-proton collisions at TeV
The -differential production cross sections of the prompt (B
feed-down subtracted) charmed mesons D, D, and D in the rapidity
range , and for transverse momentum GeV/, were
measured in proton-proton collisions at TeV with the ALICE
detector at the Large Hadron Collider. The analysis exploited the hadronic
decays DK, DK, DD, and their charge conjugates, and was performed on a
nb event sample collected in 2011 with a
minimum-bias trigger. The total charm production cross section at TeV and at 7 TeV was evaluated by extrapolating to the full phase space
the -differential production cross sections at TeV
and our previous measurements at TeV. The results were compared
to existing measurements and to perturbative-QCD calculations. The fraction of
cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/307
Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at = 2.76 TeV
The yield of charged particles associated with high- trigger
particles ( GeV/) is measured with the ALICE detector in
Pb-Pb collisions at = 2.76 TeV relative to proton-proton
collisions at the same energy. The conditional per-trigger yields are extracted
from the narrow jet-like correlation peaks in azimuthal di-hadron correlations.
In the 5% most central collisions, we observe that the yield of associated
charged particles with transverse momenta GeV/ on the
away-side drops to about 60% of that observed in pp collisions, while on the
near-side a moderate enhancement of 20-30% is found.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/350
Exercício em esteira não elevou a temperatura do casco de equinos
Objetivou-se avaliar em equino a influência do exercício progressivo e intenso realizado em esteira de alta velocidade sobre a temperatura de regiões da pele, incluindo face, pescoço e quartela, e do casco, incluindo coroa, parede e sola. Utilizaram-se cinco equinos Puro Sangue Árabes, desferrados, com idade média de 8±0,7 anos, sendo duas fêmeas e três machos, com peso corpóreo médio de 420±10kg. A intensidade de esforço foi determinada por meio da quantificação do lactato sanguíneo. As temperaturas foram determinadas com o auxílio de termógrafo, antes, durante e após o exercício. Realizou-se análise de variância seguida pelo teste de Tukey, sendo P≤0,05. A lactacidemia aumentou, principalmente nas velocidades intensas. Houve redução das temperaturas das regiões da face, pescoço e quartela após o exercício e diminuição das temperaturas da parede, coroa e sola do casco durante o exercício, enquanto a temperatura da manta de rolamento da esteira não se alterou em nenhum momento. Constatou-se indiretamente que a perfusão sanguínea do casco diminuiu durante o teste de esforço tanto em sua fase aeróbia como na anaeróbia. Nenhuma das intensidades de esforço foi capaz de alterar a temperatura da manta de rolamento da esteira. A temperatura do casco diminuída como decorrência fisiológica do esforço físico imposto, retornou aos valores normais após o término do exercício.The objective of the study was to evaluate the influence of intense and progressive exercise performed on a high speed treadmill on the temperature of the skin of the face, neck, pastern, and hoof, including the crown, sole and wall. Five unshod Arabian horses were used, with a mean age of 8±0.7 years, two females and three males, average body weight of 420±10kg. The exercise intensity was determined by quantification of blood lactate concentrations. Temperatures were determined with thermography before, during and after exercise. The effect of exercise on the temperature of the anatomic structures studied was evaluated by ANOVA for repeated measures followed by Tukey test, with P≤0.05. Blood lactate increased, especially at more intense speeds. There were decreases in temperature of the regions of the face, neck and pastern after the exercise, of the wall, crown and sole of the hoof during the effort. The temperature of the moving belt blanket bearing did not change at any time throughout the test exercise. It was found, indirectly, that the blood perfusion in the hoof decreased both during the aerobic and anaerobic phase of the exercise test. None of the effort intensities was able to change the temperature of treadmill moving belt. The temperature of the hoof reduced as a physiologic consequence of the exercise and returned to normal values after the end of the test.Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Morfologia e Fisiologia AnimalUniversidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Cirurgia e Clínica AnimalUniversidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Morfologia e Fisiologia AnimalUniversidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Cirurgia e Clínica Anima
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