Exploiting h→W∗W∗h \to W^*W^* Decays at the Upgraded Fermilab Tevatron

We study the observability of a Standard Model-like Higgs boson at an upgraded Fermilab Tevatron via the mode $h \to W^*W^*$. We concentrate on the main channel $gg \to h \to W^*W^* \to l \nu l \nu$. We also find the mode $q\bar q'\to W h \to W W^*W^* \to l^\pm \nu l^\pm \nu jj$ useful. We perform detector level simulations by making use of a Monte Carlo program SHW. Optimized searching strategy and kinematical cuts are developed. We find that with a c.m. energy of 2 TeV and an integrated luminosity of 30 fb$^{-1}$ the signal should be observable at a 3$\sigma$ level or better for the mass range of 145 GeV < m_h < 180 GeV. For 95% confidence level exclusion, the mass reach is 135 GeV < m_h <190 GeV. We also present results of studying these channels with a model-independent parameterization. Further improvement is possible by including other channels. We conclude that the upgraded Fermilab Tevatron will have the potential to significantly advance our knowledge of Higgs boson physics.Comment: 23 pages; 15 figures; 5 table

Changes of concave and convex rib-vertebral angle, angle difference and angle ratio in patients with right thoracic adolescent idiopathic scoliosis

The aim of this study is to describe the radiological changes in rib-vertebral angles (RVAs), rib-vertebral angle differences (RVADs), and rib-vertebral angle ratios (RVARas) in patients with untreated right thoracic adolescent idiopathic scoliosis and to compare with the normal subjects. The concave and convex RVA from T1 to T12, the RVADs and the RVARas were measured on AP digital radiographs of 44 female patients with right convex idiopathic scoliosis and 14 normal females. Patients were divided into three groups: normal subjects (group 1), scoliotic patients with Cobb's angle equal or <30° (group 2) and scoliotic patients with Cobb's angle over 30° (group 3). Overall values (mean±SD) of the RVAs on the concave side were 90.5°±17° in group 1, 90.3°±15.8° in group 2 and 88.8°±15.4° in group 3. On the convex side, values were 90.0°±17.3° in group 1, 86.3°±13.7° in group 2 and 80.7°±14.4° in group 3. Overall values (mean±SD) of the RVADs at all levels were 0.5°±0.7° in group 1, 4.0°±4.8° in group 2 and 8.0°±4.0° in group 3. The RVARa values (mean±SD) at all levels was 1.008°±0.012° in group 1, 1.041°±0.061° in group 2 and 1.102°±0.151° in group 3. RVAD and RVARa values in the scoliotic segment were greater in patients with untreated scoliosis over 30° than in patients with an untreated deformity of <30° or normal subjects. A significant effect between groups was observed for the RVA, RVAD and RVARa variables. Measurement of RVA, RVAD and RVARa should not only be performed at and around the apex of a thoracic spinal deformity, but also extended to the whole thoracic spin

Cervical spine sagittal alignment variations following posterior spinal fusion and instrumentation for adolescent idiopathic scoliosis

The aim of this study is to quantify the changes in the sagittal alignment of the cervical spine in patients with adolescent idiopathic scoliosis following posterior spinal fusion. Patients eligible for study inclusion included those with a diagnosis of mainly thoracic adolescent idiopathic scoliosis treated by means of posterior multisegmented hook and screw instrumentation. Pre and post-operative anterior-posterior and lateral radiographs of the entire spine were reviewed to assess the changes of cervical sagittal alignment. Thirty-two patients (3 boys, 29 girls) met the inclusion criteria for the study. The average pre-operative cervical sagittal alignment (CSA) was 4.0°±12.3° (range −30° to 40°) of lordosis. Postoperatively, the average CSA was 1.7°±11.4° (range −24° to 30°). After surgery, it was less than 20° in 27 patients (84.4%) and between 20° and 40° in 5 patients (15.6%). The results of the present study suggest that even if rod precontouring is performed and postoperative thoracic sagittal alignment is restored, improved or remains unchanged after significant correction of the deformity on the frontal plane, the inherent rigidity of the cervical spine limits changes in the CSA as the cervical spine becomes rigid over tim

Les pâturages communaux du lac Saint-Pierre : de leur histoire et de leur actualité

Au début de la colonie on trouvait des pâturages communaux dans un tiers à la moitié des seigneuries de la vallée du Saint-Laurent. Peu d'entre eux ont survécu aux vicissitudes de l'histoire et il semble que les cinq pâturages communaux du lac Saint-Pierre comptent parmi les seuls en existence aujourd'hui au Québec. Parmi les facteurs permettant d'expliquer la survivance de ces pâturages communaux, appelés ici communes, les plus évidents semblent relever du domaine de l'environnement. En effet, les communes du lac Saint-Pierre se trouvent dans des terres riveraines, basses et inondables. Elles peuvent profiter ainsi d'une certaine fertilisation naturelle à la suite des inondations printanières et, de par leur position souvent insulaire, semblent ne nécessiter qu'une clôturation limitée. Cependant, à l'examen des documents historiques concernant les communes au Québec depuis l'établissement des seigneuries au XVIIe siècle, il semble que les cinq communes encore en existence au lac Saint-Pierre aient fait l'objet d'un très grand nombre de litiges, entre les seigneurs (avant le régime anglais) ou la corporation des syndics d'une part, et les censitaires ou utilisateurs de la commune d'autre part. À ce titre d'ailleurs, elles comptent parmi les plus contestées. De plus, la cause de ces différends semble presque toujours reliée aux conditions même de l'environnement. En effet, les utilisateurs se sont toujours plaints de la maigre qualité des pâturages et du mauvais drainage des communes. Les inondations n'entraînent pas ces seuls problèmes mais peuvent également, par l'entremise des glaces errantes du printemps, arracher les quelques clôtures limitant les communes. Si de tels problèmes ont été à la source de la disparition des autres communes, pourquoi celles du lac Saint-Pierre — où ces problèmes sont particulièrement aigus — ont-elles survécu ?Les communes jouent encore aujourd'hui un rôle économique important puisqu'à chaque printemps, près de trois cents agriculteurs provenant d'un hinterland d'une soixantaine de milles de rayon viennent y mener au total près de trois mille bovins, chevaux et moutons. Cette pérennité de l'utilisation des communes ne peut cependant pas seulement s'expliquer par les avantages naturels des pâturages des pays du lac Saint-Pierre. Il semble maintenant évident que des critères d'ordre économique et même socio-psychologique particuliers à la région doivent contribuer à expliquer la survivance, à travers trois siècles d'histoire, de ces formes originales de mise en valeur agricole. C'est ce que des enquêtes actuellement en cours auprès des utilisateurs devraient permettre de mieux mesurer.During the early days of the French regime, common pastures were established on a third to a half of all the seigneuries in the St. Lawrence valley. Only a few have survived and it seems that besides the five commons in the lake St. Peter region very few are still in existence. Among the factors that contribute to explain the survival of these commons, the more obvious ones appear to be related to the local natural environment. The common pastures of lake St. Peter are located on low grounds easily covered by the spring floods. As a result they benefit from natural fertilisation and, because of their generally insular position, only need to be partly fenced. However, the historicaldocuments concerning common pastures in Québec province indicate a great number of legal disputes between the seigneurs (in pre-conquest days) or the corporation, on the one hand, and the censitaires or farmers making use of their rights on the other. Indeed, these particular commons appear to have been marred by a long series of disputes generally related to problems of the natural environment. The farmers have always complained about the poor quality of the pasture and the inadequate drainage System of the fields. These are not the only problems related to the spring floods, for even the limited fencing heavily damaged by the moving ice blocks tumbling down the St. Lawrence. If such problems have contributed to the abandonment of other commons, why have the commons of lake St. Peter — where these problems are apparently even more frequent — survived ?The commons of lake St. Peter continue to play an important economic role. Every spring nearly three hundred farmers, from sixty miles around, lead nearly three thousand cattle, horses and sheep to these pastures. The perennial character of these commons cannot be explained solely by the relative advantages of the natural pastures in the low regions bordering the lake. Reasons of an economic nature and even perhaps of a socio-psychological nature, particular to this region, contribute to explain the survival of such original but « outdated » forms of agricultural land use. Survey research, already being carried out among the users, should help solve this question

Cosmic ray tests of the D0 preshower detector

The D0 preshower detector consists of scintillator strips with embedded wavelength-shifting fibers, and a readout using Visible Light Photon Counters. The response to minimum ionizing particles has been tested with cosmic ray muons. We report results on the gain calibration and light-yield distributions. The spatial resolution is investigated taking into account the light sharing between strips, the effects of multiple scattering and various systematic uncertainties. The detection efficiency and noise contamination are also investigated.Comment: 27 pages, 24 figures, submitted to NIM