The Geometry and Moduli of K3 Surfaces

These notes will give an introduction to the theory of K3 surfaces. We begin with some general results on K3 surfaces, including the construction of their moduli space and some of its properties. We then move on to focus on the theory of polarized K3 surfaces, studying their moduli, degenerations and the compactification problem. This theory is then further enhanced to a discussion of lattice polarized K3 surfaces, which provide a rich source of explicit examples, including a large class of lattice polarizations coming from elliptic fibrations. Finally, we conclude by discussing the ample and Kahler cones of K3 surfaces, and give some of their applications.Comment: 34 pages, 2 figures. (R. Laza, M. Schutt and N. Yui, eds.

Small-angle fragmentation of carbon ions at 0.6 GeV/n: a comparison with models of ion-ion interactions

Momentum distributions of hydrogen and helium isotopes from 12C fragmentation at 3.5° were measured at 0.6 GeV/nucleon in the FRAGM experiment at ITEP TWA heavy ion accelerator. The fragments were selected by correlated time of flight and dE/dx measurements with a magnetic spectrometer with scintillation counters. The main attention was drawn to the high momentum region where the fragment velocity exceeds the velocity of the projectile nucleus. The momentum spectra of fragments span the region of the fragmentation peak as well as the cumulative region. The differential cross sections cover six orders of magnitude. The distributions measured are compared to the predictions of three ion-ion interaction models: BC, QMD and LAQGSM03.03. The kinetic energy spectra of fragments in the projectile rest frame have an exponential shape with two temperatures, being defined by their slope parameters

ПРОВЕРКА ВЗАИМОСВЯЗИ МЕЖДУ ДЕВЯТЬЮ ОДНОНУКЛЕОТИДНЫМИ ПОЛИМОРФИЗМАМИ И ИНФАРКТОМ МИОКАРДА НА СИБИРСКОЙ ПОПУЛЯЦИИ

Aim: to evaluate association between genetic polymorphism (SNPs) and myocardial infarction (identified in recent GWAS) as markers of high risk of myocardial infarction (MI) in Siberian population. Patients were divided into 2 groups — MI patients and control group (ratio 1:2) and presented the sapmle of population of Novosibirsk (9400 patients, 45–69 years) within international project HAPIEE (Health, Alcohol and Psychosocial factors In Eastern Europe). 200 patients with MI (129 men, 71 women) were included. Control group — individuals without MI (420) matched for age and sex. Genomic DNA was extracted from venous blood by phenol-chloroform extraction. Gene polymorphism of genes tested by real-time PCR according to protocol (probes TaqMan, Applied Biosystems, USA) with the use of ABI 7900HT. The following SNPs were studied: rs28711149, rs499818, rs619203, rs10757278 and rs1333049 (hr. 9), rs1376251, rs2549513, rs4804611, rs17465637. The association of SNP and MI was confirmed for 4 of 9 studied SNPs: rs1333049 (hr. 9), rs10757278 (hr. 9), rs499818 (hr. 6), rs619203 gene ROS1. Heart rate was associated with rs1333049 and rs10757278. Glucose level was associated with rs619203, rs28711149 and rs1376251. Total cholesterol and atherogenic index was associated with rs28711149. For the first time in Russian population the associations of GWAS with myocardial infarction SNPs was detected for rs619203, rs499818, rs1333049 and rs10757278. These genetic markers can be used for assessing the risk of myocardial infarction in Russian population. Цель исследования – проверить однонуклеотидные полиморфизмы, идентифицированные в недавних полногеномных ассоциативных исследованиях, на пригодность в качестве маркеров риска развития инфаркта миокарда в сибирской популяции. Группа больных инфарктом миокарда и контрольная группа (соотношение 1:2) были сформированы на основе популяционной выборки 45–69-летних жителей Новосибирска (9400 человек), созданной в рамках международного проекта HAPIEE (Health, Alcohol and Psychosocial factors In Eastern Europe). В исследование было включено 200 больных инфарктом миокарда (129 мужчин, 71 женщина), контрольную группу составили лица без инфаркта (420 человек), сопоставимые по половым и возрастным различиям. Геномную ДНК выделяли из венозной крови методом фенол-хлороформной экстракции. Полиморфизм генов тестировали посредством ПЦР в реальном времени в соответствии с протоколом фирмы производителя (зонды TaqMan, Applied Biosystems, США) на приборе ABI 7900HT. В исследование были включены следующие однонуклеотидные полиморфизмы: rs28711149, rs499818, rs619203, rs10757278 и rs1333049 (хр. 9), rs1376251, rs2549513, rs4804611, rs17465637. Для 4 из 9 исследованных однонуклеотидных полиморфизмов была подтверждена их ассоциация с инфарктом миокарда: rs1333049 (хр. 9), rs10757278 (хр. 9), rs499818 (хр. 6), rs619203 гена ROS1. С частотой сердечных сокращений были взаимосвязаны полиморфизмы rs1333049 и rs10757278, с уровнем глюкозы — rs619203, rs28711149 и rs1376251, с содержанием общего холестерина и индексом атерогенности плазмы — rs28711149. Впервые на российской популяции реплицированы результаты GWAS с инфарктом миокарда ОНП rs619203, rs499818, rs1333049 и rs10757278, Эти генетические маркеры могут использоваться для оценки риска развития инфаркта миокарда на российской популяции.

Search for narrow resonances in e+ e- annihilation between 1.85 and 3.1 GeV with the KEDR Detector

We report results of a search for narrow resonances in e+ e- annihilation at center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR detector at the VEPP-4M e+ e- collider. The upper limit on the leptonic width of a narrow resonance Gamma(R -> ee) Br(R -> hadr) < 120 eV has been obtained (at 90 % C.L.)

Measurement of main parameters of the \psi(2S) resonance

A high-precision determination of the main parameters of the \psi(2S) resonance has been performed with the KEDR detector at the VEPP-4M e^{+}e^{-} collider in three scans of the \psi(2S) -- \psi(3770) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the \psi(2S) we obtained the mass value M = 3686.114 +- 0.007 +- 0.011 ^{+0.002}_{-0.012} MeV and the product of the electron partial width by the branching fraction into hadrons \Gamma_{ee}*B_{h} = 2.233 +- 0.015 +- 0.037 +- 0.020 keV. The third error quoted is an estimate of the model dependence of the result due to assumptions on the interference effects in the cross section of the single-photon e^{+}e^{-} annihilation to hadrons explicitly considered in this work. Implicitly, the same assumptions were employed to obtain the charmonium leptonic width and the absolute branching fractions in many experiments. Using the result presented and the world average values of the electron and hadron branching fractions, one obtains the electron partial width and the total width of the \psi(2S): \Gamma_{ee} =2.282 +- 0.015 +- 0.038 +- 0.021 keV, \Gamma = 296 +- 2 +- 8 +- 3 keV. These results are consistent with and more than two times more precise than any of the previous experiments

Measurement of RudsR_{\text{uds}} and RR between 3.12 and 3.72 GeV at the KEDR detector

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have measured the values of $R_{\text{uds}}$ and $R$ at seven points of the center-of-mass energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or better than $3.3\%$ at most of energy points with a systematic uncertainty of about $2.1\%$. At the moment it is the most accurate measurement of $R(s)$ in this energy range

Changes in the middle and upper atmosphere parameters during the January 2013 sudden stratospheric warming

We present the results of complex obser-vations of various parameters of the middle and upper atmosphere over Siberia in December 2012 – January 2013, during a major sudden stratospheric warming (SSW) event. We analyze variations in ozone concentration from microwave measurements, in stratosphere and lower mesosphere temperatures from lidar and satellite measurements, in the F2-layer critical frequency (foF2), in the total electron content (TEC), as well as in the ratio of concentrations of atomic oxygen to molecular nitrogen (O/N2) in the thermosphere. To interpret the observed disturbances in the upper atmosphere, the experimental measurements are compared with the results of model calculations obtained with the Global Self-consistent Model of Thermosphere—Ionosphere—Protonosphere (GSM TIP). The response of the upper atmosphere to the SSW event is shown to be a decrease in foF2 and TEC during the evolution of the warming event and a prolonged increase in O/N2, foF2, and TEC after the SSW maximum. For the first time, we observe the relation between the increase in stratospheric ozone, thermospheric O/N2, and ionospheric electron density for a fairly long time (up to 20 days) after the SSW maximum at midlatitudes

Measurement of \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-) and \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)

The products of the electron width of the J/\psi meson and the branching fraction of its decays to the lepton pairs were measured using data from the KEDR experiment at the VEPP-4M electron-positron collider. The results are \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-)=(0.3323\pm0.0064\pm0.0048) keV, \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)=(0.3318\pm0.0052\pm0.0063) keV. Their combinations \Gamma_{ee}\times(\Gamma_{ee}+\Gamma_{\mu\mu})/\Gamma=(0.6641\pm0.0082\pm0.0100) keV, \Gamma_{ee}/\Gamma_{\mu\mu}=1.002\pm0.021\pm0.013 can be used to improve theaccuracy of the leptonic and full widths and test leptonic universality. Assuming e\mu universality and using the world average value of the lepton branching fraction, we also determine the leptonic \Gamma_{ll}=5.59\pm0.12 keV and total \Gamma=94.1\pm2.7 keV widths of the J/\psi meson.Comment: 7 pages, 6 figure

New precise determination of the \tau lepton mass at KEDR detector

The status of the experiment on the precise $\tau$ lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the $\tau^+\tau^-$ cross section behaviour around the production threshold. The preliminary result based on 6.7 pb$^{-1}$ of data is $m_{\tau}=1776.80^{+0.25}_{-0.23} \pm 0.15$ MeV. Using 0.8 pb$^{-1}$ of data collected at the $\psi'$ peak the preliminary result is also obtained: $\Gamma_{ee}B_{\tau\tau}(\psi') = 7.2 \pm 2.1$ eV.Comment: 6 pages, 8 figures; The 9th International Workshop on Tau-Lepton Physics, Tau0