Determinant representation for some transition probabilities in the TASEP with second class particles

We study the transition probabilities for the totally asymmetric simple exclusion process (TASEP) on the infinite integer lattice with a finite, but arbitrary number of first and second class particles. Using the Bethe ansatz we present an explicit expression of these quantities in terms of the Bethe wave function. In a next step it is proved rigorously that this expression can be written in a compact determinantal form for the case where the order of the first and second class particles does not change in time. An independent geometrical approach provides insight into these results and enables us to generalize the determinantal solution to the multi-class TASEP.Comment: Minor revision; journal reference adde

Chip-Firing and Rotor-Routing on Directed Graphs

We give a rigorous and self-contained survey of the abelian sandpile model and rotor-router model on finite directed graphs, highlighting the connections between them. We present several intriguing open problems.Comment: 34 pages, 11 figures. v2 has additional references, v3 corrects figure 9, v4 corrects several typo

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters

Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV

Isolated photon production is measured in proton-proton and lead-lead collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80 GeV with the CMS detector at the LHC. The measured ET spectra are found to be in good agreement with next-to-leading-order perturbative QCD predictions. The ratio of PbPb to pp isolated photon ET-differential yields, scaled by the number of incoherent nucleon-nucleon collisions, is consistent with unity for all PbPb reaction centralities.Comment: Submitted to Physics Letters

Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO

Effects of infection with Toxoplasma gondii oocysts on the intestinal wall and the myenteric plexus of chicken (Gallus gallus)

This paper aims to analyze the effects of the Toxoplasma gondii infection in the intestinal wall and myenteric plexus of chicken (Gallus gallus). Ten 36-day-old chickens were separated into two groups: control and experimental, orally inoculated with oocysts of the T. gondii strain M7741 genotype III. After 60 days the birds were submitted to euthanasia and had their duodenum removed. Part of the intestinal segments was submitted to histological routine, HE staining, PAS histochemical technique, and Alcian Blue. Qualitative analysis of the intestinal wall and comparative measurements among the groups with respect to total wall thickness, muscle tunic, mucosa, and tunica mucosa were carried out. Caliciform cells were quantified. The other part of the intestinal segments was fixed in formol acetic acid and dissected having the tunica mucosa and the tela submucosa removed. Neurons were stained with Giemsa, counted, and measured. Chickens from the experimental group presented diarrhea and inflammatory infiltrates in the tunica mucosa, thickness reduction of all the parameters assessed in the intestinal wall, and an increase of the number of caliciform cells. There was a ~70% reduction regarding the intensity of myenteric neurons; and the remaining cells presented a reduction of ~2.4% of the perikarion and ~40.5% of the nucleus (pO objetivo deste trabalho foi analisar os efeitos da infecção pelo Toxoplasma gondii sobre a parede intestinal e o plexo mientérico de Gallus gallus. Dez galinhas de 36 dias de idade separadas em dois grupos: controle e experimental inoculado com oocistos da cepa M7741 de T. gondii (genótipo III) pela via oral. Após 60 dias os animais foram submetidos à eutanásia e o duodeno coletado. Parte dos segmentos intestinais foi submetida à rotina histológica, coloração por HE e técnica histoquímica de PAS e Alcian Blue. Realizou-se uma avaliação qualitativa da parede intestinal e medidas comparativas entre os grupos da espessura da parede total, túnica muscular, muscular da mucosa e túnica mucosa. As células caliciformes foram quantificadas. Outra parte dos segmentos intestinais foi fixada em formol acético e dissecada retirando-se a túnica mucosa e a tela submucosa. Os neurônios foram corados pela técnica de Giemsa, contados e mensurados. Os animais do grupo experimental apresentaram diarréia e infiltrados inflamatórios na túnica mucosa, redução da espessura de todos os parâmetros avaliados da parede intestinal e aumento do número das células caliciformes. Houve uma redução de ~70% da densidade dos neurônios mientéricos e as células remanescentes sofreram redução de ~2,4% do pericário e ~40,5% do núcleo (p<0,05). A infecção crônica induzida por oocistos de T. gondii levou a atrofia da parede intestinal, aumento da secreção de mucinas, morte e atrofia dos neurônios do plexo mientérico de galinhas. A morte e atrofia dos neurônios do plexo mientérico podem estar envolvidas na causa da diarréia observada em galinhas com toxoplasmose

Measurement of the mass difference between top quark and antiquark in pp collisions at root s=8 TeV

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