9 research outputs found

    Transverse momentum spectra of charged particles in proton-proton collisions at s=900\sqrt{s} = 900 GeV with ALICE at the LHC

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    The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at s=900\sqrt{s} = 900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (∣η∣<0.8)(|\eta|<0.8) over the transverse momentum range 0.15<pT<100.15<p_{\rm T}<10 GeV/cc. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for ∣η∣<0.8|\eta|<0.8 is <pT>INEL=0.483±0.001\left<p_{\rm T}\right>_{\rm INEL}=0.483\pm0.001 (stat.) ±0.007\pm0.007 (syst.) GeV/cc and \left_{\rm NSD}=0.489\pm0.001 (stat.) ±0.007\pm0.007 (syst.) GeV/cc, respectively. The data exhibit a slightly larger <pT>\left<p_{\rm T}\right> than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET.Comment: 20 pages, 8 figures, 2 tables, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/390

    Inclusive photon production at forward rapidities in proton\u2013proton collisions at 1a s = 0.9, 2.76 and 7 TeV

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    The multiplicity and pseudorapidity distribu- tions of inclusive photons have been measured at forward rapidities (2.3 < \u3b7 < 3.9) in proton\u2013proton collisions at three center-of-mass energies, 1as = 0.9, 2.76 and 7 TeV using the ALICE detector. It is observed that the increase in the average photon multiplicity as a function of beam energy is compatible with both a logarithmic and a power-law dependence. The relative increase in average photon multi- plicity produced in inelastic pp collisions at 2.76 and 7 TeV center-of-mass energies with respect to 0.9 TeV are 37.2 \ub1 0.3% (stat) \ub1 8.8% (sys) and 61.2 \ub1 0.3% (stat) \ub1 7.6% (sys), respectively. The photon multiplicity distributions for all center-of-mass energies are well described by negative binomial distributions. The multiplicity distributions are also presented in terms of KNO variables. The results are com- pared to model predictions, which are found in general to underestimate the data at large photon multiplicities, in par- ticular at the highest center-of-mass energy. Limiting frag- mentation behavior of photons has been explored with the data, but is not observed in the measured pseudorapidity range

    A Review of Success Factors for Piglet Fostering in Lactation

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    Piglet movement from one sow to another, or fostering, is required in modern pig farming but there is little available literature on the most effective strategy. In this review, we focus on the behavioural and physiological mechanisms responsible for piglet survival and growth, and have identified six key principles. (1) Colostrum provides piglets with warmth, energy and immunity. It is most accessible during the first 12 h from the birth sow, therefore no piglet should be moved before this; (2) To ensure even intake of birth sow colostrum, techniques such as split suckling prior to piglet movement should be implemented; (3) Udder assessment for functional teats should occur at farrowing, with number of fostered piglets not exceeding teat number; (4) Primiparous sows should receive as many piglets as the udder allows to maximise mammary stimulation, although older parities should be assessed for rearing ability; (5) Piglet fostering should occur between 12 and 24 h and movement kept to a minimum to prevent transfer of disease; Litter outliers should be moved and relocated to a litter of similar size; (6) Piglet movement after 24 h should be minimised. When required, strategies such as nurse usage should be employed. These principles will result in improved farrowing house performance by increasing the litter weight weaned per sow

    Genomic Analysis of Purebred and Crossbred Angus Cows Quantifies Heterozygosity, Breed, and Additive Effects on Components of Reproduction

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    Multiple studies have quantified the production differences of Hereford Angus crossbreds compared to purebred Angus for a range of traits including growth, carcass, and reproductive traits. This study aims to quantify breed and heterosis effects on maternal performance using genomics. Thirty Hereford and thirty Angus sires were mated to 1100 Angus heifers and cows in a large commercial herd run on pasture at Musselroe Bay, Tasmania, Australia. Approximately 1650 calves were born. Heifers were weaned, scanned for attainment of puberty prior to joining at approximately 15 months of age, joined, and then recorded for status of pregnancy, calving, lactating, 2nd pregnancy, and weaning of second calf. Heterozygosity effects were significant for heifer pre-joining weight and height as well as proportion pubertal. Breed differences were significant for the same traits plus pregnancy rate at second joining and proportion rearing two calves. Genetic parameters were reported for 13 traits. On average, higher genetic merit (Estimated Breeding Value, EBV percentile) Hereford bulls were used than Angus for growth and puberty, but they were similar for fat and reproduction. Days to calving BREEDPLAN EBVs of the sires were related to puberty and reproduction. Scrotal size BREEDPLAN EBVs of the sires were related to attainment of puberty genomic EBVs calculated. In summary, breed differences in growth and puberty were due to heterosis, but there was an advantage of Hereford genes for reproductive performance. Ongoing emphasis on selection for reduced days to calving and estimation of multi-breed EBVs is important

    Measurement of pion, kaon and proton production in proton–proton collisions at s=7\sqrt{s} = 7 s = 7 TeV

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    The measurement of primary pi(+/-), K-+/-, p and (p) over bar production at mid-rapidity (|y| < 0.5) in proton-proton collisions at root s = 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ionisation energy-loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/c for pions, from 0.2 up to 6 GeV/c for kaons and from 0.3 up to 6 GeV/c for protons. The measured spectra and particle ratios are compared with quantum chromodynamics-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies

    Forward-backward multiplicity correlations in pp collisions at s s \sqrt{s} = 0.9, 2.76 and 7 TeV

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    The strength of forward-backward (FB) multiplicity correlations is measured by the ALICE detector in proton-proton (pp) collisions at 1as = 0.9, 2.76 and 7TeV. The measurement is performed in the central pseudorapidity region (|\u3b7| 0.3GeV/c. Two separate pseudorapidity windows of width (\u3b4\u3b7) ranging from 0.2 to 0.8 are chosen symmetrically around \u3b7 = 0. The multiplicity correlation strength (bcorr) is studied as a function of the pseudorapidity gap (\u3b7gap) between the two windows as well as the width of these windows. The correlation strength is found to decrease with increasing \u3b7gap and shows a non-linear increase with \u3b4\u3b7. A sizable increase of the correlation strength with the collision energy, which cannot be explained exclusively by the increase of the mean multiplicity inside the windows, is observed. The correlation coefficient is also measured for multiplicities in different configurations of two azimuthal sectors selected within the symmetric FB \u3b7-windows. Two different contributions, the short-range (SR) and the long-range (LR), are observed. The energy dependence of bcorr is found to be weak for the SR component while it is strong for the LR component. Moreover, the correlation coefficient is studied for particles belonging to various transverse momentum intervals chosen to have the same mean multiplicity. Both SR and LR contributions to bcorr are found to increase with pT in this case. Results are compared to PYTHIA and PHOJET event generators and to a string-based phenomenological model. The observed dependencies of bcorr add new constraints on phenomenological models

    Inclusive photon production at forward rapidities in proton–proton collisions at s\mathbf {\sqrt{s}} s = 0.9, 2.76 and 7 TeV

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    Forward-backward multiplicity correlations in pp collisions at s s \sqrt{s} = 0.9, 2.76 and 7 TeV

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    Multiplicity dependence of the average transverse momentum in pp, p–Pb, and Pb–Pb collisions at the LHC

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