Influence of hadronic interaction models and the cosmic ray spectrum on the high energy atmospheric muon and neutrino flux

The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A reviewed calculation of lepton spectra produced in cosmic-ray induced extensive air showers is carried out with a primary cosmic-ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to derive the inclusive differential spectra (yields) of muons, muon neutrinos and electron neutrinos at the surface for energies between 80 GeV and hundreds of PeV. The air shower simulator {\sc corsika} 6.990 was used for showering and propagation of the secondary particles through the atmosphere, employing the established high-energy hadronic interaction models {\sc sibyll} 2.1, {\sc qgsjet-01} and {\sc qgsjet-ii 03}. We show that the performance of the interaction models allows makes it possible to predict the spectra within experimental uncertainties, while {\sc sibyll} generally yields a higher flux at the surface than the qgsjet models. The calculation of the flavor and charge ratios has lead to inconsistent results, mainly influenced by the different representations of the K/$\pi$ ratio within the models. Furthermore, we could quantify systematic uncertainties of atmospheric muon- and neutrino fluxes, associated to the models of the primary cosmic-ray spectrum and the interaction models. For most recent parametrizations of the cosmic-ray primary spectrum, atmospheric muons can be determined with an uncertainty smaller than $^{+15}_{-13}$% of the average flux. Uncertainties of the muon- and electron neutrino fluxes can be calculated within an average error of $^{+32}_{-22}$% and $^{+25}_{-19}$%, respectively.Comment: 16 pages, 10 figures, version 2 includes analytic approximatio

Lp Fourier multipliers on compact Lie groups

In this paper we prove Lp multiplier theorems for invariant and non-invariant operators on compact Lie groups in the spirit of the well-known Hormander-Mikhlin theorem on Rn and its variants on tori Tn. We also give applications to a-priori estimates for non-hypoelliptic operators. Already in the case of tori we get an interesting refinement of the classical multiplier theorem.Comment: 22 pages; minor correction

de Branges-Rovnyak spaces: basics and theory

For $S$ a contractive analytic operator-valued function on the unit disk ${\mathbb D}$, de Branges and Rovnyak associate a Hilbert space of analytic functions ${\mathcal H}(S)$ and related extension space ${\mathcal D(S)}$ consisting of pairs of analytic functions on the unit disk ${\mathbb D}$. This survey describes three equivalent formulations (the original geometric de Branges-Rovnyak definition, the Toeplitz operator characterization, and the characterization as a reproducing kernel Hilbert space) of the de Branges-Rovnyak space ${\mathcal H}(S)$, as well as its role as the underlying Hilbert space for the modeling of completely non-isometric Hilbert-space contraction operators. Also examined is the extension of these ideas to handle the modeling of the more general class of completely nonunitary contraction operators, where the more general two-component de Branges-Rovnyak model space ${\mathcal D}(S)$ and associated overlapping spaces play key roles. Connections with other function theory problems and applications are also discussed. More recent applications to a variety of subsequent applications are given in a companion survey article

Three-body correlations in direct reactions: Example of 6^{6}Be populated in (p,n)(p,n) reaction

The $^{6}$Be continuum states were populated in the charge-exchange reaction $^1$H($^{6}$Li,$^{6}$Be)$n$ collecting very high statistics data ($\sim 5 \times 10^6$ events) on the three-body $\alpha$+$p$+$p$ correlations. The $^{6}$Be excitation energy region below $\sim 3$ MeV is considered, where the data are dominated by contributions from the $0^+$ and $2^+$ states. It is demonstrated how the high-statistics few-body correlation data can be used to extract detailed information on the reaction mechanism. Such a derivation is based on the fact that highly spin-aligned states are typically populated in the direct reactions.Comment: submitted to Physical Review

New insight into the low-energy 9^9He spectrum

The spectrum of $^9$He was studied by means of the $^8$He($d$,$p$)$^9$He reaction at a lab energy of 25 MeV/n and small center of mass (c.m.) angles. Energy and angular correlations were obtained for the $^9$He decay products by complete kinematical reconstruction. The data do not show narrow states at $\sim$1.3 and $\sim$2.4 MeV reported before for $^9$He. The lowest resonant state of $^9$He is found at about 2 MeV with a width of $\sim$2 MeV and is identified as $1/2^-$. The observed angular correlation pattern is uniquely explained by the interference of the $1/2^-$ resonance with a virtual state $1/2^+$ (limit on the scattering length is obtained as $a > -20$ fm), and with the $5/2^+$ resonance at energy $\geq 4.2$ MeV.Comment: 5 pages, 4 figures, 2 table

10He low-lying states structure uncovered by correlations

The 0+ ground state of the 10He nucleus produced in the 3H(8He,p)10He reaction was found at about $2.1\pm0.2$ MeV (\Gamma ~ 2 MeV) above the three-body 8He+n+n breakup threshold. Angular correlations observed for 10He decay products show prominent interference patterns allowing to draw conclusions about the structure of low-energy excited states. We interpret the observed correlations as a coherent superposition of the broad 1- state having a maximum at energy 4-6 MeV and the 2+ state above 6 MeV, setting both on top of the 0+ state "tail". This anomalous level ordering indicates that the breakdown of the N=8 shell known in 12Be thus extends also to the 10He system.Comment: 5 pages, 5 figure

8.5. Cyclic vectors in spaces of analytic functions

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41570/1/10958_2005_Article_BF01221529.pd

The 6^{6}H states studied in the d(8He,α)d(^8\text{He},\alpha) reaction and evidence of extremely correlated character of the 5^{5}H ground state

The extremely neutron-rich system $^{6}$H was studied in the direct $^2\text{H}(^8\text{He},{^4\text{He}})^{6}$H transfer reaction with a 26 $A$ MeV secondary $^{8}$He beam. The measured missing mass spectrum shows a resonant state in $^{6}$H at $6.8(3)$ MeV relative to the $^3$H+$3n$ threshold. The population cross section of the presumably $p$-wave states in the energy range from 4 to 8 MeV is $d\sigma/d\Omega_{\text{c.m.}} \simeq 190(40)$ $\mu$b/sr in the angular range $5^{\circ}<\theta_{\text{c.m.}}<16^{\circ}$. The obtained missing mass spectrum is free of the $^{6}$H events below 3.5 MeV ($d\sigma/d\Omega_{\text{c.m.}} \lesssim 3$ $\mu$b/sr in the same angular range). The steep rise of the $^{6}$H missing mass spectrum at 3 MeV allows to show that $4.5(3)$ MeV is the lower limit for the possible resonant state energy in $^{6}$H tolerated by our data. According to paring energy estimates, such a $4.5(3)$ MeV resonance is a realistic candidate for the $^{6}$H ground state (g.s.). The obtained results confirm that the decay mechanism of the $^{7}$H g.s.\ (located at 2.2 MeV above the $^{3}$H+$4n$ threshold) is the ``true'' (or simultaneous) $4n$ emission. The resonance energy profiles and the momentum distributions of the sequential $^{6}$H \,\rightarrow \, ^5H(g.s.)+n\, \rightarrow \, ^3H+$3n$ decay fragments were analyzed by the theoretically-updated direct four-body-decay and sequential-emission mechanisms. The measured momentum distributions of the $^{3}$H fragments in the $^{6}$H rest frame indicate very strong ``dineutron-type'' correlations in the $^{5}$H ground state decay.Comment: 9 pages, 11 figure

Способ хирургического лечения острого флотирующего тромбоза илеофеморального сегмента глубоких вен нижних конечностей у пациентов ортопедического профиля

Introduction. The incidence rate of vein thrombosis stands at 180 cases per 100 thousand per year and reaches 200 cases per 100 thousand in older age population.This study aims to assess the efficacy and safety of the proposed method of retrograde vacuum aspiration performed under the conditions of increased intra-abdominal pressure in patients with iliofemoral deep vein thrombosis.Materials and methods. The analysis of surgical treatment of acute floating iliofemoral deep vein thrombosis in 52 orthopedic surgery patients following hip and knee arthroplasty. Acute floating iliofemoral deep vein thrombosis was identified in the postoperative period where the length of the floating part exceeded 4 cm. Patients received emergency treatment in the form of either the surgical prophylaxis of pulmonary embolism (study group n = 18) or a vena cava filter implantation in the infrarenal segment of the vein (control group n = 34).Results and discussion. Patency of the iliofemoral segment was completely restored after the surgery in all the 18 patients in the study group. In the control group, however,, all the 34 patients (px2 &lt; 0.001) retained thrombotic masses in the iliofemoral segment even at the time of discharge from hospital . The length of hospital stay was also different between the comparison groups, amounting to 7 ± 0.74 days for the study group and the patients without thromboembolic complications, and to 21 ± 1.5 days (pm u — 0.0124) for the control.Conclusions 1. The new surgical method proposed for the treatment of acute floating iliofemoral deep vein thrombosis makes it possible to highly effectively restore the full patency of the vein in the shortest possible timeframe. This method is safe and more cost-effective than the classic surgical approach to the treatment of this pathology. 2. Further research into the efficacy and safety of the method proposed is needed as well as a longer term follow up on a larger number of patients.Введение. Эпидемиология тромбозов венозной системы достигает 180 случаев на 100 тыс. населения в год и увеличивается у возрастных пациентов до 200 случаев на 100 тыс. населения.Цель — изучить эффективность и безопасность предложенной методики ретроградной вакуум-аспирации в условиях повышенного внутрибрюшного давления при тромбозе илеофеморального сегмента глубоких вен нижних конечностей.Материалы и методы. Проведен анализ хирургического лечения острого флотирующего тромбоза илеофеморального сегмента глубоких вен нижних конечностей у 52 пациентов ортопедического профиля после эндопротезирования тазобедренных и коленных суставов. В послеоперационном периоде был выявлен острый флотирующий тромбоз илеофеморального сегмента глубоких вен с длиной флотирующей части более 4 см. В срочном порядке пациентам выполнена хирургическая профилактика ТЭЛА, (группа исследования n = 18) и имплантация кава-фильтра в инфраренальный отдел нижней полой вены (контрольная группа n = 34).Результаты и обсуждение. У всех 18 пациентов исследуемой группы после операции наблюдалась полная проходимость илеофеморального сегмента, в то время как в группе сравнения даже к моменту выписки тромботические массы в илеофеморальном сегменте сохранялись у всех 34 пациентов (рх2 &lt; 0,001). Сроки госпитализации пациентов также отличались в группах сравнения: в исследуемой группе — 7 ± 0,74 дня, так же как у пациентов без тромбоэмболических осложнений, а у пациентов группы сравнения составили 21 ± 1,5 дня (pm u — 0,0124).Выводы. 1. Предложенный способ хирургического лечения острого флотирующего тромбоза илеофеморального сегмента глубоких вен нижних конечностей позволяет в кратчайшие сроки с высокой эффективностью полностью восстановить проходимость просвета вен, является безопасным и экономически выгодным по сравнению с классическим подходом хирургического лечения данной патологии. 2. Необходимо продолжить исследование эффективности, безопасности и отдаленных результатов предложенной методики с вовлечением большего количества пациентов