Papers by vichot jongrungrot
Journal of High Energy Physics, 2014
A search for a standard model Higgs boson decaying into a pair of τ leptons is performed using ev... more A search for a standard model Higgs boson decaying into a pair of τ leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 fb −1 at a centre-of-mass energy of 7 TeV and 19.7 fb −1 at 8 TeV. Each τ lepton decays hadronically or leptonically to an electron or a muon, leading to six different final states for the τ-lepton pair, all considered in this analysis. An excess of events is observed over the expected background contributions, with a local significance larger than 3 standard deviations for m H values between 115 and 130 GeV. The best fit of the observed H → τ τ signal cross section times branching fraction for m H = 125 GeV is 0.78 ± 0.27 times the standard model expectation. These observations constitute evidence for the 125 GeV Higgs boson decaying to a pair of τ leptons.
Physical Review D, 2013
Measurements are presented of the production of primary K 0 S and à particles in proton-proton co... more Measurements are presented of the production of primary K 0 S and à particles in proton-proton collisions at ffiffi ffi s p ¼ 7 TeV in the region transverse to the leading charged-particle jet in each event. The average multiplicity and average scalar transverse momentum sum of K 0 S and à particles measured at pseudorapidities jj < 2 rise with increasing charged-particle jet p T in the range 1-10 GeV=c and saturate in the region 10-50 GeV=c. The rise and saturation of the strange-particle yields and transverse momentum sums in the underlying event are similar to those observed for inclusive charged particles, which confirms the impact-parameter picture of multiple parton interactions. The results are compared to recent tunes of the PYTHIA Monte Carlo event generator. The PYTHIA simulations underestimate the data by 15%-30% for K 0 S mesons and by about 50% for à baryons, a deficit similar to that observed for the inclusive strange-particle production in non-single-diffractive proton-proton collisions. The constant strange-to charged-particle activity ratios with respect to the leading jet p T and similar trends for mesons and baryons indicate that the multiparton-interaction dynamics is decoupled from parton hadronization, which occurs at a later stage.
Journal of High Energy Physics, 2014
Measurements of the tt charge asymmetry using the dilepton decay channel in pp collisions at √ s ... more Measurements of the tt charge asymmetry using the dilepton decay channel in pp collisions at √ s = 7 TeV The CMS collaboration
Journal of High Energy Physics, 2013
The first measurement of the electroweak production cross section of a Z boson with two jets (Zjj... more The first measurement of the electroweak production cross section of a Z boson with two jets (Zjj) in pp collisions at $ \sqrt{s}=7 $ TeV is presented, based on a data sample recorded by the CMS experiment at the LHC with an integrated luminosity of 5 fb−1. The cross section is measured for the ℓℓjj (ℓ = e, μ) final state in the kinematic region m ℓℓ > 50 GeV, m jj > 120 GeV, transverse momenta $ p_{\mathrm{T}}^{\mathrm{j}}>25 $ GeV and pseudorapidity |η j| < 4.0. The measurement, combining the muon and electron channels, yields σ = 154 ± 24 (stat.) ± 46 (exp. syst.) ± 27 (th. syst.) ± 3 (lum.) fb, in agreement with the theoretical cross section. The hadronic activity, in the rapidity interval between the jets, is also measured. These results establish an important foundation for the more general study of vector boson fusion processes, of relevance for Higgs boson searches and for measurements of electroweak gauge couplings and vector boson scattering.
Journal of High Energy Physics, 2013
The underlying event activity in proton-proton collisions at forward pseudo-rapidity (−6.6 < η... more The underlying event activity in proton-proton collisions at forward pseudo-rapidity (−6.6 < η < −5.2) is studied with the CMS detector at the LHC, using a novel observable: the ratio of the forward energy density, dE/dη, for events with a charged-particle jet produced at central pseudorapidity (|η jet| < 2) to the forward energy density for inclusive events. This forward energy density ratio is measured as a function of the central jet transverse momentum, p T, at three different pp centre-of-mass energies ( $ \sqrt{s}=0.9 $ , 2.76, and 7 TeV). In addition, the $ \sqrt{s} $ evolution of the forward energy density is studied in inclusive events and in events with a central jet. The results are compared to those of Monte Carlo event generators for pp collisions and are discussed in terms of the underlying event. Whereas the dependence of the forward energy density ratio on jet p T at each $ \sqrt{s} $ separately can be well reproduced by some models, all models fail to simul...
Journal of High Energy Physics, 2012
A search for microscopic black holes in pp collisions at a center-of-mass energy of 7 TeV is pres... more A search for microscopic black holes in pp collisions at a center-of-mass energy of 7 TeV is presented. The data sample corresponds to an integrated luminosity of 4.7 fb−1 recorded by the CMS experiment at the LHC in 2011. Events with large total transverse energy have been analyzed for the presence of multiple energetic jets, leptons, and photons, which are typical signals of evaporating semiclassical and quantum black holes, and string balls. Agreement with the expected standard model backgrounds, which are dominated by QCD multijet production, has been observed for various combined multiplicities of jets and other reconstructed objects in the final state. Model-independent limits are set on new physics processes producing high-multiplicity, energetic final states. In addition, new model-specific indicative limits are set excluding semiclassical and quantum black holes with masses below 3.8 to 5.3 TeV and string balls with masses below 4.6 to 4.8 TeV . The analysis has a substanti...
Journal of High Energy Physics, 2013
A study of proton-proton collisions in which two b hadrons are produced in association with a Z b... more A study of proton-proton collisions in which two b hadrons are produced in association with a Z boson is reported. The collisions were recorded at a centre-of-mass energy of 7 TeVwith the CMS detector at the LHC, for an integrated luminosity of 5.2 fb−1. The b hadrons are identified by means of displaced secondary vertices, without the use of reconstructed jets, permitting the study of b-hadron pair production at small angular separation. Differential cross sections are presented as a function of the angular separation of the b hadrons and the Z boson. In addition, inclusive measurements are presented. For both the inclusive and differential studies, different ranges of Z boson momentum are considered, and each measurement is compared to the predictions from different event generators at leading-order and next-to-leading-order accuracy.
Journal of High Energy Physics, 2013
Results of searches for heavy stable charged particles produced in pp collisions at $ \sqrt{s} $ ... more Results of searches for heavy stable charged particles produced in pp collisions at $ \sqrt{s} $ = 7 and 8 TeV are presented corresponding to an integrated luminosity of 5.0 fb−1 and 18.8 fb−1, respectively. Data collected with the CMS detector are used to study the momentum, energy deposition, and time-of-flight of signal candidates. Leptons with an electric charge between e/3 and 8e, as well as bound states that can undergo charge exchange with the detector material, are studied. Analysis results are presented for various combinations of signatures in the inner tracker only, inner tracker and muon detector, and muon detector only. Detector signatures utilized are long time-of-flight to the outer muon system and anomalously high (or low) energy deposition in the inner tracker. The data are consistent with the expected background, and upper limits are set on the production cross section of long-lived gluinos, scalar top quarks, and scalar τ leptons, as well as pair produced long-liv...
Journal of High Energy Physics, 2013
A search for exclusive or quasi-exclusive W+W− production by photon-photon interactions, pp → p(*... more A search for exclusive or quasi-exclusive W+W− production by photon-photon interactions, pp → p(*)W+W−p(*), at $ \sqrt{s}=7 $ TeV is reported using data collected by the CMS detector with an integrated luminosity of 5.05 fb−1. Events are selected by requiring a μ ±e∓ vertex with no additional associated charged tracks and dilepton transverse momentum p T(μ ±e∓) > 30 GeV. Two events passing all selection requirements are observed in the data, compared to a standard model expectation of 2.2 ± 0.4 signal events with 0.84 ± 0.15 background. The tail of the dilepton p T distribution is studied for deviations from the standard model. No events are observed with p T > 100 GeV. Model-independent upper limits are computed and compared to predictions involving anomalous quartic gauge couplings. The limits on the parameters $ {{{a_{0,C}^W}} \left/ {{{\varLambda^2}}} \right.} $ with a dipole form factor and an energy cutoff Λcutoff = 500 GeV are of the order of 10−4.
Physical Review Letters, 2013
A study is presented of the mass and spin-parity of the new boson recently observed at the LHC at... more A study is presented of the mass and spin-parity of the new boson recently observed at the LHC at a mass near 125 GeV. An integrated luminosity of 17.3 fb −1 , collected by the CMS experiment in proton-proton collisions at center-of-mass energies of 7 and 8 TeV, is used. The measured mass in the ZZ channel, where both Z bosons decay to e or µ pairs, is 126.2 ± 0.6 (stat.) ± 0.2 (syst.) GeV. The angular distributions of the lepton pairs in this channel are sensitive to the spin-parity of the boson. Under the assumption of spin 0, the present data are consistent with the pure scalar hypothesis, while disfavoring the pure pseudoscalar hypothesis.
Physical Review Letters, 2014
Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symm... more Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top quark (the top squark) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 fb −1 of proton-proton collision data at √ s = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the top squark mass below 360 to 410 GeV, depending on the higgsino mass.
Physical Review Letters, 2012
A search for new physics is performed in events with two same-sign isolated leptons, hadronic jet... more A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4:98 fb À1 produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.
Physical Review D, 2012
Results are presented on the production of jets of particles in association with a Z= Ã boson, in... more Results are presented on the production of jets of particles in association with a Z= Ã boson, in protonproton collisions at ffiffi ffi s p ¼ 7 TeV with the ATLAS detector. The analysis includes the full 2010 data set, collected with a low rate of multiple proton-proton collisions in the accelerator, corresponding to an integrated luminosity of 36 pb À1. Inclusive jet cross sections in Z= Ã events, with Z= Ã decaying into electron or muon pairs, are measured for jets with transverse momentum p T > 30 GeV and jet rapidity jyj < 4:4. The measurements are compared to next-to-leading-order perturbative QCD calculations, and to predictions from different Monte Carlo generators implementing leading-order matrix elements supplemented by parton showers.
Physical Review D, 2013
Results are presented of a search for the production of new particles decaying to pairs of parton... more Results are presented of a search for the production of new particles decaying to pairs of partons (quarks, antiquarks, or gluons), in the dijet mass spectrum in proton-proton collisions at ffiffi ffi s p ¼ 8 TeV. The data sample corresponds to an integrated luminosity of 4:0 fb À1 , collected with the CMS detector at the LHC in 2012. No significant evidence for narrow resonance production is observed. Upper limits are set at the 95% confidence level on the production cross section of hypothetical new particles decaying to quarkquark, quark-gluon, or gluon-gluon final states. These limits are then translated into lower limits on the masses of new resonances in specific scenarios of physics beyond the standard model. The limits reach up to 4.8 TeV, depending on the model, and extend previous exclusions from similar searches performed at lower collision energies. For the first time mass limits are set for the Randall-Sundrum graviton model in the dijet channel.
The European Physical Journal C, 2013
A search for a standard-model-like Higgs boson in the H → WW and H → ZZ decay channels is reporte... more A search for a standard-model-like Higgs boson in the H → WW and H → ZZ decay channels is reported, for Higgs boson masses in the range 145 < m H < 1000 GeV. The search is based upon proton-proton collision data samples corresponding to an integrated luminosity of up to 5.1 fb −1 at √ s = 7 TeV and up to 5.3 fb −1 at √ s = 8 TeV, recorded by the CMS experiment at the LHC. The combined upper limits at 95 % confidence level on products of the cross section and branching fractions exclude a standard-model-like Higgs boson in the range 145 < m H < 710 GeV, thus extending the mass region excluded by CMS from 127-600 GeV up to 710 GeV.
Agricultural & Natural Resource Economics eJournal, 2021
Goat raising in Thailand is not different in practices from other types of agriculture in terms o... more Goat raising in Thailand is not different in practices from other types of agriculture in terms of its small-scale household owned and diversity of activities. This study was conducted on 5 farmers practiced different 5 systems in Satun province, Thailand. Many farmers have built economic resilience in the agricultural farming systems under risks and uncertainties brought by changing government policies. This study seeks to examine the resilience of the economy through the scenario building in an integrated goat-other agricultural activities farming system adapted by farmers when facing external threats. This study found that the total annual margin of raising goats, with large diversity from 2.27 to 30.51 percent and in terms of cost and benefits of 5 plots in 2018 showed a gross margin of between 49,002 to 306,313 baht per year and plot 2 was an interesting farming system with higher net profits than the other plots. Since, the goat has low operation cost, it plays an important ro...
This study aimed to determine the definition of Agroforestry and the functions of Agroforestry Sy... more This study aimed to determine the definition of Agroforestry and the functions of Agroforestry System that could be modified to strengthen agrarian communities. The methodology of this study consisted of literature review and data analysis by content analysis technique. The results indicated that the definition of agroforestry could be shown in easy formula: Agriculture + Forestry = Agroforestry or building forests through agriculture. By cultivating crops in a condition similar to nature, it is possible to bring diversity back to fields and achieve sustainable production of crops that were previously mono-cultural. This study found three functions of Agroforestry System: 1) economic functions, composed of the four sub-functions of various, even and resilient incomes, production efficiency, expenditure reduction and economic immunity; 2) environmental functions, composed of the seven sub-functions of land conservation, sedimentary reduction, flood and droughty relief, storm resistan...
BOIS & FORETS DES TROPIQUES
Le caoutchouc est une culture de rente importante pour la plupart des petits agri- culteurs. En T... more Le caoutchouc est une culture de rente importante pour la plupart des petits agri- culteurs. En Thaïlande, plus de 95 % du caoutchouc est produit par les petits agri- culteurs qui cultivent principalement l’hé- véa en monoculture (90 % des planta- tions). Mais du fait de la fluctuation des prix, la monoculture est de plus en plus souvent remplacée par des systèmes agroforestiers à base d’hévéa (SAF- hévéa). Cette étude a pour objectif d’éva- luer les principales trajectoires des agri- culteurs qui passent de la monoculture au SAF-hévéa. Les résultats montrent qu’ils suivent quatre trajectoires : conversion de leur verger de fruitiers en SAF-hévéa ; conversion de leur parcelle forestière en SAF-hévéa ; conversion de leur monocul- ture d’hévéa en SAF-hévéa ; création d’un SAF-hévéa dès la plantation. Il est égale- ment constaté que les planteurs prati- quent sept types d’association en fonc- tion de l’utilisation économique des arbres intercalaires. L’étude économique a été complétée ...
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Papers by vichot jongrungrot