1,610 research outputs found
Gaussian limits for multidimensional random sequential packing at saturation (extended version)
Consider the random sequential packing model with infinite input and in any
dimension. When the input consists of non-zero volume convex solids we show
that the total number of solids accepted over cubes of volume is
asymptotically normal as . We provide a rate of
approximation to the normal and show that the finite dimensional distributions
of the packing measures converge to those of a mean zero generalized Gaussian
field. The method of proof involves showing that the collection of accepted
solids satisfies the weak spatial dependence condition known as stabilization.Comment: 31 page
On recurrence and ergodicity for geodesic flows on noncompact periodic polygonal surfaces
We study the recurrence and ergodicity for the billiard on noncompact
polygonal surfaces with a free, cocompact action of or . In the
-periodic case, we establish criteria for recurrence. In the more difficult
-periodic case, we establish some general results. For a particular
family of -periodic polygonal surfaces, known in the physics literature
as the wind-tree model, assuming certain restrictions of geometric nature, we
obtain the ergodic decomposition of directional billiard dynamics for a dense,
countable set of directions. This is a consequence of our results on the
ergodicity of \ZZ-valued cocycles over irrational rotations.Comment: 48 pages, 12 figure
Vicious Walkers and Hook Young Tableaux
We consider a generalization of the vicious walker model. Using a bijection
map between the path configuration of the non-intersecting random walkers and
the hook Young diagram, we compute the probability concerning the number of
walker's movements. Applying the saddle point method, we reveal that the
scaling limit gives the Tracy--Widom distribution, which is same with the limit
distribution of the largest eigenvalues of the Gaussian unitary ensemble.Comment: 23 pages, 5 figure
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Search for lepton-flavour-violating decays of Higgs-like bosons.
A search is presented for a Higgs-like boson with mass in the range 45 to 195 GeV/c2 decaying into a muon and a tau lepton. The dataset consists of proton-proton interactions at a centre-of-mass energy of 8 TeV , collected by the LHCb experiment, corresponding to an integrated luminosity of 2 fb-1 . The tau leptons are reconstructed in both leptonic and hadronic decay channels. An upper limit on the production cross-section multiplied by the branching fraction at 95% confidence level is set and ranges from 22 pb for a boson mass of 45 GeV/c2 to 4 pb for a mass of 195 GeV/c2
ĐĐĐĐĐ ĐĐĄĐĐĐĐЧĐĐĄĐĐĐŻ ĐĐХйРĐĐĐąĐĐĐĐŻ ĐĄ ĐĐźĐĐĐĐХйРĐĐĐĐĐĄĐąĐĐĐĐ
The arm of the research. To develop a way to perform the laparoscopic total gastrectomy with jejunal interposition (Longmireâs procedure).Material and methods. The study presents the technology of laparoscopic total gastrectomy with a lymph node dissection D1α and jejunal interposition. After removal of the gaster with the tumor through a mini-laparotomy (2 inch), the jejunum was cut approximately45 cm distally to the ligament of Treitz. A circular stapler was used to perform an esophago-jejunostomy with Roux-en-Y reconstruction using a standard technology. The second stage is forming a segment of the small intestine for jejunal interposition. The third stage is entering the head of the circular stapling apparatus into the stump of the duodenum on a probe retrogradely through the afferent loop of the small intestine. The fourth stage is stapled anastomosis between a free segment of the jejunum and the duodenum with the circular stapler. The procedure is finalized with hand-sewn anastomosis between the afferent and efferent loops of the small intestine.Results. The presented technology was used to perform surgery on one patient. The increase in operative time did not lead to increased intraoperative blood loss and longer post-operative bed-days. After 1 year the patient shows no evidence of a tumor progression, manifestations of reflux esophagitis, and dumping syndrome. Conclusion. The proposed technology allows laparoscopic total gastrectomy with jejunal interposition via a mini-invasive technology.Â ĐŠĐ”Đ»Ń ĐžŃŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐžŃ â ŃĐ°Đ·ŃĐ°Đ±ĐŸŃĐ°ŃŃ ŃĐżĐŸŃĐŸĐ± ĐČŃĐżĐŸĐ»ĐœĐ”ĐœĐžŃ Đ»Đ°ĐżĐ°ŃĐŸŃĐșĐŸĐżĐžŃĐ”ŃĐșĐŸĐč гаŃŃŃŃĐșŃĐŸĐŒĐžĐž Ń ŃĐŸŃ
ŃĐ°ĐœĐ”ĐœĐžĐ”ĐŒ паŃŃажа ĐżĐŸ ĐĐĐ ĐżŃŃŃĐŒ плаŃŃĐžĐșĐž ŃĐ”ĐłĐŒĐ”ĐœŃĐŸĐŒ ŃĐŸĐœĐșĐŸĐč ĐșĐžŃĐșĐž бДз ŃĐŸŃĐŒĐžŃĐŸĐČĐ°ĐœĐžŃ ŃДзДŃĐČŃĐ°ŃĐ°.ĐĐ°ŃĐ”ŃОал Đž ĐŒĐ”ŃĐŸĐŽŃ. ĐŃДЎŃŃĐ°ĐČĐ»Đ”ĐœĐ° ŃĐ”Ń
ĐœĐŸĐ»ĐŸĐłĐžŃ Đ»Đ°ĐżĐ°ŃĐŸŃĐșĐŸĐżĐžŃĐ”ŃĐșĐŸĐč гаŃŃŃŃĐșŃĐŸĐŒĐžĐž Ń Đ»ĐžĐŒŃĐŸĐŽĐžŃŃĐ”ĐșŃОДĐč Đ1α Đž плаŃŃĐžĐșĐŸĐč жДлŃĐŽĐșĐ° ŃĐ”ĐłĐŒĐ”ĐœŃĐŸĐŒ ŃĐŸĐœĐșĐŸĐč ĐșĐžŃĐșĐž Ń ĐČĐșĐ»ŃŃĐ”ĐœĐžĐ”ĐŒ ĐČ ĐżĐ°ŃŃаж ĐŽĐČĐ”ĐœĐ°ĐŽŃĐ°ŃОпДŃŃŃĐœĐŸĐč ĐșĐžŃĐșĐž бДз ŃĐŸŃĐŒĐžŃĐŸĐČĐ°ĐœĐžŃ ŃДзДŃĐČŃĐ°ŃĐ°. ĐŃĐŸĐžĐ·ĐČĐŸĐŽĐžŃŃŃ Đ»Đ°ĐżĐ°ŃĐŸŃĐșĐŸĐżĐžŃĐ”ŃĐșĐ°Ń ĐłĐ°ŃŃŃŃĐșŃĐŸĐŒĐžŃ. ĐĐŸŃлД ŃĐŽĐ°Đ»Đ”ĐœĐžŃ ĐżŃДпаŃĐ°ŃĐ° ŃĐ”ŃДз ĐŒĐžĐœĐžĐŽĐŸŃŃŃĐż пДŃĐČŃĐŒ ŃŃĐ°ĐżĐŸĐŒ ĐœĐ°ĐșлаЎŃĐČĐ°Đ”ŃŃŃ ŃĐžŃĐșŃĐ»ŃŃĐœŃĐŒ аппаŃĐ°ŃĐŸĐŒ ŃĐ·ĐŸŃĐ°ĐłĐŸŃĐœŃĐ”ŃĐŸĐ°ĐœĐ°ŃŃĐŸĐŒĐŸĐ· ĐœĐ° Đ Ń-пДŃлД ĐżĐŸ ŃŃĐ°ĐœĐŽĐ°ŃŃĐœĐŸĐč ŃĐ”Ń
ĐœĐŸĐ»ĐŸĐłĐžĐž. ĐŃĐŸŃŃĐŒ ŃŃĐ°ĐżĐŸĐŒ ŃĐŸŃĐŒĐžŃŃĐ”ŃŃŃ ĐžĐœŃĐ”ŃĐżĐŸĐœĐžŃŃĐ”ĐŒŃĐč ŃĐ”ĐłĐŒĐ”ĐœŃ ŃĐŸĐœĐșĐŸĐč ĐșĐžŃĐșĐž Оз Đ ŃпДŃлО. ĐąŃĐ”ŃŃĐžĐŒ ŃŃĐ°ĐżĐŸĐŒ ĐČ ĐșŃĐ»ŃŃŃ ĐŽĐČĐ”ĐœĐ°ĐŽŃĐ°ŃОпДŃŃŃĐœĐŸĐč ĐșĐžŃĐșĐž ĐČĐČĐŸĐŽĐžŃŃŃ ĐłĐŸĐ»ĐŸĐČĐșĐ° ŃĐžŃĐșŃĐ»ŃŃĐœĐŸĐłĐŸ ŃŃĐžĐČĐ°ŃŃĐ”ĐłĐŸ аппаŃĐ°ŃĐ° ŃĐ”ŃŃĐŸĐłŃĐ°ĐŽĐœĐŸ ĐœĐ° Đ·ĐŸĐœĐŽĐ” ŃĐ”ŃДз ĐżŃĐžĐČĐŸĐŽŃŃŃŃ ĐżĐ”ŃĐ»Ń ŃĐŸĐœĐșĐŸĐč ĐșĐžŃĐșĐž. ЧДŃĐČŃŃŃŃĐŒ ŃŃĐ°ĐżĐŸĐŒ ĐœĐ°ĐșлаЎŃĐČĐ°Đ”ŃŃŃ Đ°ĐżĐżĐ°ŃĐ°ŃĐœŃĐč Đ”ŃĐœĐŸĐŽŃĐŸĐŽĐ”ĐœĐŸĐ°ĐœĐ°ŃŃĐŸĐŒĐŸĐ· ĐŒĐ”Đ¶ĐŽŃ ŃĐ”ĐłĐŒĐ”ĐœŃĐŸĐŒ ŃĐŸĐœĐșĐŸĐč ĐșĐžŃĐșĐž Đž ĐŽĐČĐ”ĐœĐ°ĐŽŃĐ°ŃОпДŃŃŃĐœĐŸĐč ĐșĐžŃĐșĐŸĐč. ĐпДŃĐ°ŃĐžŃ Đ·Đ°ĐČĐ”ŃŃĐ°Đ”ŃŃŃ ĐœĐ°Đ»ĐŸĐ¶Đ”ĐœĐžĐ”ĐŒ Đ°ĐœĐ°ŃŃĐŸĐŒĐŸĐ·Đ° ĐŒĐ”Đ¶ĐŽŃ ĐżŃĐžĐČĐŸĐŽŃŃĐ”Đč Đž ĐŸŃĐČĐŸĐŽŃŃĐ”Đč пДŃĐ»ŃĐŒĐž ŃĐŸĐœĐșĐŸĐč ĐșĐžŃĐșĐž.РДзŃĐ»ŃŃĐ°ŃŃ. ĐĐŸ ĐŸĐżĐžŃĐ°ĐœĐœĐŸĐč ŃĐ”Ń
ĐœĐŸĐ»ĐŸĐłĐžĐž ĐżŃĐŸĐŸĐżĐ”ŃĐžŃĐŸĐČĐ°Đœ ĐŸĐŽĐžĐœ паŃĐžĐ”ĐœŃ. ĐŁĐČДлОŃĐ”ĐœĐžĐ” ĐČŃĐ”ĐŒĐ”ĐœĐž ĐŸĐżĐ”ŃĐ°ŃОО ĐœĐ” ĐżŃĐžĐČĐ”Đ»ĐŸ Đș ŃĐČДлОŃĐ”ĐœĐžŃ ĐžĐœŃŃĐ°ĐŸĐżĐ”ŃĐ°ŃĐžĐŸĐœĐœĐŸĐč ĐșŃĐŸĐČĐŸĐżĐŸŃĐ”ŃĐž Đž ŃĐŽĐ»ĐžĐœĐ”ĐœĐžŃ ĐżĐŸŃĐ»Đ”ĐŸĐżĐ”ŃĐ°ŃĐžĐŸĐœĐœĐŸĐłĐŸ ĐșĐŸĐčĐșĐŸ-ĐŽĐœŃ. ЧДŃДз 1 ĐłĐŸĐŽ Ń Đ±ĐŸĐ»ŃĐœĐŸĐłĐŸ ĐœĐ”Ń ĐżŃĐžĐ·ĐœĐ°ĐșĐŸĐČ ĐŸĐżŃŃ
ĐŸĐ»Đ”ĐČĐŸĐłĐŸ ĐżŃĐŸĐłŃĐ”ŃŃĐžŃĐŸĐČĐ°ĐœĐžŃ, ĐżŃĐŸŃĐČĐ»Đ”ĐœĐžĐč ŃĐ”ŃĐ»ŃĐșŃ-ŃĐ·ĐŸŃагОŃĐ° Đž ĐŽĐ”ĐŒĐżĐžĐœĐł-ŃĐžĐœĐŽŃĐŸĐŒĐ°.ĐĐ°ĐșĐ»ŃŃĐ”ĐœĐžĐ”. ĐŃĐ”ĐŽĐ»Đ°ĐłĐ°Đ”ĐŒĐ°Ń ŃŃ
Đ”ĐŒĐ° лапаŃĐŸŃĐșĐŸĐżĐžŃĐ”ŃĐșĐŸĐč гаŃŃŃŃĐșŃĐŸĐŒĐžĐž ĐżĐŸĐ·ĐČĐŸĐ»ŃĐ”Ń ĐČŃĐżĐŸĐ»ĐœĐžŃŃ ĐŸĐżĐ”ŃĐ°ŃĐžŃ Ń Đ”ŃĐœĐŸĐłĐ°ŃŃŃĐŸĐżĐ»Đ°ŃŃĐžĐșĐŸĐč ĐżĐŸ ĐŒĐžĐœĐž-ĐžĐœĐČĐ°Đ·ĐžĐČĐœĐŸĐč ŃĐ”Ń
ĐœĐŸĐ»ĐŸĐłĐžĐž.
Observation of an Excited Bc+ State
Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+Ï+Ï- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bcâ(2S31)+ state reconstructed without the low-energy photon from the Bcâ(1S31)+âBc+Îł decay following Bcâ(2S31)+âBcâ(1S31)+Ï+Ï-. A second state is seen with a global (local) statistical significance of 2.2Ï (3.2Ï) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date
Bose-Einstein correlations of same-sign charged pions in the forward region in pp collisions at âs=7 TeV
Bose-Einstein correlations of same-sign charged pions, produced in protonproton collisions at a 7 TeV centre-of-mass energy, are studied using a data sample collected
by the LHCb experiment. The signature for Bose-Einstein correlations is observed in the
form of an enhancement of pairs of like-sign charged pions with small four-momentum
difference squared. The charged-particle multiplicity dependence of the Bose-Einstein correlation parameters describing the correlation strength and the size of the emitting source
is investigated, determining both the correlation radius and the chaoticity parameter. The
measured correlation radius is found to increase as a function of increasing charged-particle
multiplicity, while the chaoticity parameter is seen to decreas
Study of J /Ï production in Jets
The production of J/Ï mesons in jets is studied in the forward region of proton-proton collisions using data collected with the LHCb detector at a center-of-mass energy of 13 TeV. The fraction of the jet transverse momentum carried by the J/Ï meson, z(J/Ï)âĄpT(J/Ï)/pT(jet), is measured using jets with pT(jet)>20 GeV in the pseudorapidity range 2.5<η(jet)<4.0. The observed z(J/Ï)distribution for J/Ï mesons produced in b-hadron decays is consistent with expectations. However, the results for prompt J/Ï production do not agree with predictions based on fixed-order nonrelativistic QCD. This is the first measurement of the pT fraction carried by prompt J/Ï mesons in jets at any experiment
Study of charmonium production in b -hadron decays and first evidence for the decay Bs0
Using decays to Ï-meson pairs, the inclusive production of charmonium states in b-hadron decays is studied with pp collision data corresponding to an integrated luminosity of 3.0 fbâ1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting byBC ⥠B(b â C X) Ă B(C â ÏÏ) the inclusive branching fraction of a b hadron to a charmonium state C that decays into a pair of Ï mesons, ratios RC1C2 ⥠BC1 /BC2 are determined as RÏc0ηc(1S) = 0.147 ± 0.023 ± 0.011, RÏc1ηc(1S) =0.073 ± 0.016 ± 0.006, RÏc2ηc(1S) = 0.081 ± 0.013 ± 0.005,RÏc1 Ïc0 = 0.50 ± 0.11 ± 0.01, RÏc2 Ïc0 = 0.56 ± 0.10 ± 0.01and Rηc(2S)ηc(1S) = 0.040 ± 0.011 ± 0.004. Here and below the first uncertainties are statistical and the second systematic.Upper limits at 90% confidence level for the inclusive production of X(3872), X(3915) and Ïc2(2P) states are obtained as RX(3872)Ïc1 < 0.34, RX(3915)Ïc0 < 0.12 andRÏc2(2P)Ïc2 < 0.16. Differential cross-sections as a function of transverse momentum are measured for the ηc(1S) andÏc states. The branching fraction of the decay B0s â ÏÏÏ is measured for the first time, B(B0s â ÏÏÏ) = (2.15±0.54±0.28±0.21B)Ă10â6. Here the third uncertainty is due to the branching fraction of the decay B0s â ÏÏ, which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse Ï polarization is observed.The measurements allow the determination of the ratio of the branching fractions for the ηc(1S) decays to ÏÏ and p p asB(ηc(1S)â ÏÏ)/B(ηc(1S)â p p) = 1.79 ± 0.14 ± 0.32
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