373 research outputs found
Bottomonia Hadroproduction
We analyze Tevatron data of bottomonium hadroproduction in the framework of
the colour-octet model (COM) implemented in the event generator PYTHIA using
CTEQ4L PDF taking into account initial-state radiation of gluons and
Altarelli-Parisi evolution of final-state gluons. We obtain new values for the
colour-octet matrix elements relevant to this production process for the
Upsilon(nS) family (n=1,2,3), finding that the ^1S_0^{(8)}+^3P_J^{(8)}
contributions are not needed in the fit. We show the different contributions to
Upsilon(1S) production at Tevatron for p_T>8 GeV, comparing them with CDF data.
Finally we extrapolate to LHC energies to predict Upsilon(nS) production rates.Comment: Talk given at 4th International Conference on Hyperons, Charm and
Beauty Hadrons, Valencia, Spain, 27-30 Jun 2000. LaTeX, 4 pages, 4 EPS
figure
Bottomonium Production at the Tevatron and the LHC
Inclusive bottomonium hadroproduction at the Tevatron is firstly examined in
a Monte Carlo framework with the colour-octet mechanism implemented in the
event generation. We extract some NRQCD colour-octet matrix elements relevant
for hadroproduction. Remarkably we find a quite small
contribution (compatible with zero) from feeddown of states
produced through the colour-octet mechanism: indirect production
via decays should be mainly ascribed to the colour-singlet model.
Finally we extrapolate to LHC energies to predict prompt
production rates.Comment: LaTeX, 11 pages, 6 EPS figure
Extended HQEFT Lagrangian and currents
From the tree-level heavy quark effective Lagrangian keeping
particle-antiparticle mixed sectors we derive the vector current coupling to a
hard gluonic field allowing for heavy quark-antiquark pair annihilation and
creation.Comment: Talk given at 4th International Conference on Hyperons, Charm and
Beauty Hadrons, Valencia, Spain, 27-30 Jun 2000. LaTeX, 4 pages, 1 EPS figur
Results from Bottomonia Production at the Tevatron and Prospects for the LHC
We extend our previous analysis on inclusive heavy quarkonia hadroproduction
to the whole Upsilon(nS) (n=1,2,3) resonance family. We use a Monte Carlo
framework with the colour-octet mechanism implemented in the PYTHIA event
generator. We include in our study higher order QCD effects such as
initial-state emission of gluons and Altarelli-Parisi evolution of final-state
gluons. We extract some NRQCD colour-octet matrix elements relevant for
Upsilon(nS) (n=1,2,3) hadroproduction from CDF data at the Fermilab Tevatron.
Then we extrapolate to LHC energies to predict prompt bottomonia production
rates. Finally, we examine the prospect to probe the gluon density in protons
from heavy quarkonia inclusive hadroproduction at high transverse momentum and
its feasibility in LHC general-purpose experiments.Comment: LaTeX, 30 pages, 30 EPS figure
Searching for mesons in the ATLAS experiment at LHC
We discuss the feasibility of the observation of the signal from mesons
in the ATLAS experiment of the LHC collider at a luminosity of ${\approx}\
10^{33}^{-2}^{-1}B_c{\rightarrow}J/\psi \piJ/\psi{\rightarrow}\mu^+\mu^-B_c40B_c$ mass could be achieved
after one year of running.Comment: Latex,7 pages including 3 uuencoded Postscript figures appended at
the end of the latex fil
New extraction of color-octet NRQCD matrix elements from charmonium hadroproduction
We re-analyze Tavatron data on charmonium hadroproduction in the framework of the color-octet model implemented in the event generator PYTHIA taking into account initial-state radiation of gluons and Altarelli-Parisi evolution of final-state gluons fragmenting into cc¯ pairs. We obtain new values for the color-octet matrix elements relevant to this production process. We discuss the sensitivity of our results to the transverse momentum lower cut-off employed in the generation to avoid the problematic pt→0 region, arguing about the reliability of our previous extraction of the NRQCD matrix elements for the 3S(8)1 and 1S(8)0+3P(8)J contributions. Finally we extrapolate to LHC energies to get predictions on the J/ψ direct production rate
Oral lichen planus and diabetes mellitus. A clinico-phatological study
A study was made of 72 patients with oral lichen planus associated (n = 28) or not with diabetes mellitus (n = 44). No significant differences were observed between both groups in terms of the location of the lichen planus lesions on the buccal mucosa, palate, gums or floor of the mouth. On the other hand, the diabetics exhibited a greater frequency of oral lichen planus on the tongue. Atrophic-erosive lesions were more common in patients with lichen planus associated with diabetes. Finally, no differences were observed between the two groups in terms of absolute inflammatory infiltrate in the connective tissue of the oral lichen planus lesions.Nous avons effectué une étude sur deux groupes de patients atteints de lichen plan buccal, le premier associé au diabètes sucré (N = 28) et le second (N = 44) sans cette association. Nous n’observons pas de différences significatives entre eux, en ce qui concerne la localisation du lichen plan dans la muqueuse buccale, le palais, les gencives ou le plancher bouche. Nous trouvons cependant une plus grande fréquence de la localisation au niveau de la langue dans le lichen plan avec diabètes. Mais en même temps, nous détectons une fréquence plus importante de lésions atrophiques-érosives dans le premier groupe que dans le second.En dernier lieu, il n’existe pas de différences entre les deux, en ce qui concerne la quantité, en valeur absolue, de l’infiltration inflammatoire dans les tissus conjonctifs des lésions buccales du lichen plan
Hormonal responses to competition
S p o rts competitions have been employed to analy ze the influence of social confro n t ations on hormonal levels. Howeve r, results have been inconsistent. Seve ral va ri ables such as outcome, phy s i c a l exe rtion, mood and causal at t ri bution have been considered as important mediat o rs of this infl u e nc e. Our aim was to examine their role in the testosterone and cortisol responses to a real confro n t ation. To this end, twe l ve judoists who part i c i p ated in a competition between clubs we re studied. Results showed non significant diffe rences depending on outcome in hormones, physical exe rtion, mood and causal at t ri bution; only sat i s faction with the outcome being significant. Intere s t i n g ly, testoste rone response was positive ly associated with self-ap p raisal of perfo rmance and at t ri bution of outcome to personal effo rt. Cortisol response showed a ve ry consistent re l ationship with negat ive moo d. These findings support a clear association of competition-induced hormonal responses with cogni t ive and emotional aspects rather than with objective (outcome or physical exe rtion) ch a ra c t e ri stics of the situat i o n
J/psi Production at the LHC
We firstly examine hadroproduction of prompt J/psi's at the Fermilab Tevatron
in a Monte Carlo Framework by means of the event generator PYTHIA 5.7 in which
those colour-octet matrix elements processes relevant for charmonium production
have been implemented accordingly. We find that colour-octet matrix elements
presented in literature from p-pbar collider data are systematically
overestimated due to overlooking of the effective primordial transverse
momentum of partons (i.e. including higher-order QCD effects). We estimate the
size of these effects using different parton distribution functions. Finally,
after normalization to Tevatron data, we extrapolate up to LHC energies making
a prediction on the expected pt differential cross-section for charmonium.Comment: 4 pages, LaTex, 3 Figures included in the text, Contribution to the
2nd Int. Conference on Hyperons, charm and beauty hadrons (Montreal, Aug
27-30, 1996
Oral lichen planus. An evolutive clinical and histological study of 45 patients followed up on for five years
A study is made of 45 patients clinically and histologically diagnosed of oral lichen planus, and followed up on for 5 years. The course of the disease was monitored after three months and one, two and five years. The patients were classified in terms of lesion evolution (healed, improved, stationary or worse). Two evolutive groups were established for statistical purposes: (a) favorable (healed or improved lesions) and unfavorable cases (stationary or worsened oral lesions); and (b) healed and non-healed cases. Statistical correlations were established between these evolutive groups and different clinical and histological parameters, in an attempt to identify parameters of predictive value in the course of the disease. No statistically significant results were obtained, with the exception of inflammatory infiltrate. Thus, the depth of this infiltrate was found to be greater in patients with an unfavorable evolution (p = 0.02) than in those with a favorable course. Likewise, the inflammatory infiltrate was greater in non-healed than in healed cases.Dans ce travail, nous présentons une série de 45 patients, suivis pendant 5 ans, diagnostiqués cliniquement et histologiquement de lichen plan oral. Des contrôles évolutifs réalisés au bout de 3 mois, un an, deux ans et au bout de cinq ans ont classé les patients en fonction de l’évolution qu’ils présentaient en cas qui avaient guéri de leurs lésions, qui s’étaient améliorés, qui continuaient pareil et finalement ceux qui avaient empiré. Vis-à-vis des statistiques 2 groupes évolutifs se sont faits: 1) cas favorables (les guéris et ceux qui s’étaient améliorés), cas défavorables (ceux qui ne présentaient aucun changement ou ceux qui avaient empiré de leurs lésions intraorales) et 2) cas guéris, cas non-guéris. Diverses corrélations statistiques se sont établies entre ces groupes évolutifs et une série de variables cliniques et histologiques pour trouver un paramètre ayant une valeur de prédiction dans l’évolution de la maladie. Nous n’avons trouvé aucune donnée significativement statistique si l’on excepte une infiltration inflammatoire. Ainsi, nous démontrons une plus grande profondité moyenne de celle-ci dans les cas qui présentent une évolution défavorable (p = 0.02) que dans les cas favorables. De la même façon, nous trouvons une plus grande infiltration dans les cas non-guéris que dans les guéris
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