Jet substructure as a new Higgs search channel at the LHC

It is widely considered that, for Higgs boson searches at the Large Hadron Collider, WH and ZH production where the Higgs boson decays to b anti-b are poor search channels due to large backgrounds. We show that at high transverse momenta, employing state-of-the-art jet reconstruction and decomposition techniques, these processes can be recovered as promising search channels for the standard model Higgs boson around 120 GeV in mass.Comment: 4 pages, 3 figure

Electroweak 2 -> 2 amplitudes for electron-positron annihilation at TeV energies

The non-radiative scattering amplitudes for electron-positron annihilation into quark and lepton pairs in the TeV energy range are calculated in the double-logarithmic approximation. The expressions for the amplitudes are obtained using infrared evolution equations with different cut-offs for virtual photons and for W and Z bosons, and compared with previous results obtained with an universal cut-off.Comment: Revtex4, 17 pages, 7 figures. Some minor changes made, more refs adde

QCD factorization for forward hadron scattering at high energies

We consider the QCD factorization of DIS structure functions at small x and amplitudes of 2->2 -hadronic forward scattering at high energy. We show that both collinear and k_T-factorization for these processes can be obtained approximately as reductions of a more general (totally unintegrated) form of the factorization. The requirement of ultraviolet and infrared stability of the factorization convolutions allows us to obtain restrictions on the fits for the parton distributions in k_T- and collinear factorization.Comment: 18 pages, 10 figures In the present version misprints found in the prevcious version are corrected and some more details are explaine

Breeding and selection of mini-pigs in the ICG SB RAS

The article considers methods used for breeding and selection of mini-pigs in the ICG, SB RAS, the theoretical justifcation of these methods and the purposes for which they are used. We showed the genealogical structure of the herd and the contribution of inbreeding to the genetic similarity of modern representatives of genealogical lines and families with the founders of the breeding group. We characterized the phenotypic diversity of the ICG mini-pigs in colours, weight categories, types of growth and features of constitution. We listed measures supporting genetic diversity in the herd of the ICG mini-pigs. We explained the possibility of using similarity indices calculated by using portions of the ancestors’ blood (genome) for the selection of parental pairs and the evaluation of genetic consolidation of the herd. We showed that the average index of similarity between males and females, calculated by using portions of the ancestors’ blood, in the ICG minipigs is close to the limit value. It turned out that effective evaluation of the genetic potential of mini-pigs in growth rate and fnal size of individuals is only possible under the condition of a rich and full feeding of young animals. The time scale of estimation of growth of live weight of the ICG mini-pigs for three weight categories allocated in the selection group is presented. The types of growth and development of mini-pigs observed in the ICG breeding group and the type inherent to individuals in the small weight category are considered. We justifed the minimum live weight of a newborn piglet in the herd of the ICG mini-pigs. Values of optimal multiple pregnancy for the three categories of ICG mini-pig sows were calculated

The heat capacity of nitrogen chains in grooves of single-walled carbon nanotube bundles

The heat capacity of bundles of closed-cap single-walled carbon nanotubes (SWNT) with one-dimensional chains of nitrogen molecules adsorbed in the grooves has been first experimentally studied at temperatures from 2K to 40K using an adiabatic calorimeter. The contribution of nitrogen C(T) to the total heat capacity has been separated. In the region 2-8K the behaviour of the curve C(T) is qualitatively similar to the theoretical prediction of the phonon heat capacity of 1D chains of krypton (Kr) atoms localized in the grooves of SWNT bundles. Below 3K the dependence C(T) is linear. Above 8K the dependence C(T) becomes steeper in comparison with the case of Kr atoms. This behaviour of the heat capacity C(T) is due to the contribution of the rotational degrees of freedom of the nitrogen molecules.Comment: 15 pages, 4 figure

Роль возникновения задней отслойки стекловидного тела в патогенезе первичной закрытоугольной глаукомы

PURPOSE: Study of changes in the posterior part of eyes predisposed to primary angle-closure glaucoma (PACG) that contribute to patient's conversion from risk group to the disease. METHODS: 135 patients (223 eyes) anatomically predisposed to PACG development (37-88 years old, 87 females, 48 males) were studied and monitored for 4 years. PACG diagnosis had not been verified previous to the study. 176 eyes were pair eyes of 88 patients; in other 47 cases only one eye of the patient was studied because PACG had already been diagnosed in the second eye. Apart from standard ophthalmological study all patients underwent ß-scan ocular ultrasound and prone-position provocative test for angle-closure glaucoma (Hyams test), during which the patients lay in prone position for 1 hour and IOP was measured before and right after the test. RESULTS: The eyes were divided into 2 groups depending on the Hyams test results: the 1-st group included patients with positive test results (IOP increase >5 mmHg) and the 2-nd group (risk group) - patients with negative test results (IOP increaseЦЕЛЬ. Изучение в заднем отрезке глаза изменений, участвующих в переходе глаз, предрасположенных к первичной закрытоугольной глаукоме (ПЗУГ), из группы риска в реальную форму заболевания. МЕТОДЫ. В течение 4 лет обследовано 223 глаза (135 пациентов в возрасте от 37 до 88 лет, из них 87 женщин и 48 мужчин) с анатомической предрасположенностью к ПЗУГ, находящихся в группе риска, но пока еще без зафиксированных подъемов внутриглазного давления (ВГД) и без верифицированного диагноза ПЗУГ. 176 глаз были парными глазами у 88 пациентов. У 47 пациентов исследовался только один глаз, а второй не соответствовал критериям исследования, поскольку ранее на нем уже была диагностирована ПЗУГ и назначено лечение. Среди методов исследования делали акцент на проведение нагрузочной пробы Хеймса (с укладкой пациента вниз лицом на 1 час и контролем ВГД до и после пробы) и на ультразвуковое В-сканирование заднего отрезка глаза. РЕЗУЛЬТАТЫ. После проведения пробы Хеймса пациенты были разделены на 2 группы: 1-я группа с положительным результатом пробы (подъем ВГД более 5 мм) и 2-я - с отрицательным результатом пробы. Положительный результат пробы Хеймса рассматривался как решающий фактор для установления диагноза ПЗУГ и назначения необходимого лазерного или медикаментозного лечения, а случаи с отрицательной пробой Хеймса оставляли в группе риска с последующим мониторингом и контрольными исследованиями 1 раз в 6 месяцев. У 31 пациента, когда исследовались оба глаза, на одном глазу проба Хеймса была положительной, а на другом - отрицательной. Выявлено, что проба Хеймса была положительной только на тех глазах (67,7%), на которых эхографически зафиксировано наличие задней отслойки стекловидного тела (ЗОСТ). При отсутствии ЗОСТ, несмотря на узкий УПК, проба Хеймса всегда была отрицательной. В 27 глазах в процессе динамического мониторинга была выявлена трансформация нагрузочной пробы Хеймса из отрицательной в положительную, что трактовали как переход глаза из группы риска в группу с реальной формой ПЗУГ. Во всех случаях трансформация результатов пробы сопровождалась обнаружением ЗОСТ, которая в этих глазах отсутствовала в начале мониторингового наблюдения. ЗАКЛЮЧЕНИЕ. Представленные наблюдения позволяют предположить существование связи между возникновением ЗОСТ и переходом глаз с анатомической предрасположенностью к ПЗУГ из группы риска в реальную форму заболевания. Сделано предположение, что возникновение ЗОСТ нарушает стабильность положения СТ в витреальной полости, что при неблагоприятных условиях приводит к микроэкскурсиям СТ и смещению кпереди иридохрусталиковой диафрагмы. Это провоцирует возникновение гидродинамических блоков и повышение ВГД по закрытоугольному типу

Monte Carlo simulation for jet fragmentation in SUSY-QCD

We present results from a new Monte Carlo simulation for jet fragmentation in QCD and SUSY QCD for large primary energies $\sqrt s$ up to $10^{16}$ GeV. In the case of SUSY QCD the simulation takes into account not only gluons and quarks as cascading particles, but also their supersymmetric partners. A new model-independent hadronization scheme is developed, in which the hadronization functions are found from LEP data. An interesting feature of SUSY QCD is the prediction of a sizeable flux of the lightest supersymmetric particles (LSPs), if R-parity is conserved. About 10% of the jet energy is transferred to LSPs which, owing to their harder spectra, constitute an important part of the spectra for large $x=E/E_{jet}$. Spectra of protons and of secondary particles, photons and neutrinos, are also calculated. These results have implications for the decay of superheavy particles with masses up to the GUT scale, which have been suggested as a source of ultrahigh energy cosmic rays.Comment: latex, 25 pages with 17 eps figure

Small x behavior of parton distributions. A study of higher twist effects

Higher twist corrections to the structure function F_2 at small x are studied for the case of a flat initial condition for the twist-two QCD evolution in the next-to-leading order approximation. We present an analytical parameterization of the contributions from the twist-two and higher twist operators of the Wilson operator product expansion. Higher twist terms are evaluated using two different approaches, one motivated by BFKL and the other motivated by the renormalon formalism. The results of the latter approach are in very good agreement with deep inelastic scattering data from HERA.Comment: 46 pages, 9 figures, typeset using REVTeX. Misprints corrected, new results, discussions, references and acknowledgements added, 2 pictures replaced. The conclusions remain unchange

A Catching Trap for All Antiproton Seasons

We describe the origin, development, and status of the Los Alamos antiproton catching trap. Originally designed for the antiproton gravity experiment, it now is clear that this device can be a source of low-energy antiprotons for a wide range of physics, both on site, at CERN, and also off site.Comment: 18 pages, LaTeX, 6 figures available upon request, In honor of Herbert Walthe