Parity nonconserving two-pion exchange in elastic proton-proton scattering

Parity nonconserving two-pion exchange in elastic pp scattering is investigated in the presence of phenomenological strong distortions in various models. Parity violation is included in the nucleon-pion vertex considering NN and N Delta(1232) intermediate states in box and crossed box diagrams. Using the derived parity nonconserving two-pion exchange potential we calculate the longitudinal analyzing power A_L in elastic $pp$ scattering. The predicted effect is of the same order as vector meson exchanges.Comment: 13 pages, 8 eps figure

Positive pion absorption on 3He using modern trinucleon wave functions

We study pion absorption on 3He employing trinucleon wave functions calculated from modern realistic NN interactions (Paris, CD Bonn). Even though the use of the new wave functions leads to a significant improvement over older calculations with regard to both cross section and polarization data, there are hints that polarization data with quasifree kinematics cannot be described by just two-nucleon absorption mechanisms.Comment: 14 pages, 6 figure

Exact solutions of the isoholonomic problem and the optimal control problem in holonomic quantum computation

The isoholonomic problem in a homogeneous bundle is formulated and solved exactly. The problem takes a form of a boundary value problem of a variational equation. The solution is applied to the optimal control problem in holonomic quantum computer. We provide a prescription to construct an optimal controller for an arbitrary unitary gate and apply it to a $k$-dimensional unitary gate which operates on an $N$-dimensional Hilbert space with $N \geq 2k$. Our construction is applied to several important unitary gates such as the Hadamard gate, the CNOT gate, and the two-qubit discrete Fourier transformation gate. Controllers for these gates are explicitly constructed.Comment: 19 pages, no figures, LaTeX2

Electronic cooling of a submicron-sized metallic beam

We demonstrate electronic cooling of a suspended AuPd island using superconductor-insulator-normal metal tunnel junctions. This was achieved by developing a simple fabrication method for reliably releasing narrow submicron sized metal beams. The process is based on reactive ion etching and uses a conducting substrate to avoid charge-up damage and is compatible with e.g. conventional e-beam lithography, shadow-angle metal deposition and oxide tunnel junctions. The devices function well and exhibit clear cooling; up to factor of two at sub-kelvin temperatures.Comment: 4 pages, 3 figure

Complete next-to-leading order calculation for pion production in nucleon-nucleon collisions at threshold

Based on a counting scheme that explicitly takes into account the large momentum sqrt(M m_pi) characteristic for pion production in nucleon-nucleon collisions we calculate all diagrams for the reaction NN --> NN pi at threshold up to next-to-leading order. At this order there are no free parameters and the size of the next-to-leading order contributions is in line with the expectation from power counting. The sum of loop corrections at that order vanishes for the process pp --> pp pi^0 at threshold. The total contribution at next-to-leading order from loop diagrams that include the delta degree of freedom vanishes at threshold in both reaction channels pp --> pp pi^0, pn pi^+.Comment: 9 pages, 4 figure

Mortonin jalan ja Freibergin taudin yleisyyden ja variaation arviointi Pohjois-Suomen 1966 syntymäkohortista

Tiivistelmä. Mortonin jalka tarkoittaa jalkaterän anatomista poikkeavuutta, jossa ensimmäisen varpaan metatarsaali (jalkapöydänluu) on lyhyt suhteessa toisen varpaan metatarsaaliin. Mortonin jalka on väestössä yleinen anatominen variaatio. Sen esiintyvyys vaihtelee eri maissa muutamasta prosentista kymmeniin prosentteihin. Freibergin taudilla tarkoitetaan väestössä suhteellisen harvinaista jalan toisen (harvemmin myös kolmannen tai neljännen) metatarsaalin distaalipään nivelpinnan nekrotisoitumista ja sitä seuraavaa kiputilaa. Tauti on yleisempi naisilla kuin miehillä (suhteessa 5:1). Tässä tutkimuksessa luokiteltiin Pohjois-Suomen syntymäkohortti 1966 osaotoksen jalkateräröntgenaineistoa ja selvitettiin metatarsaalien pituuksia ja Freibergin taudin yleisyyttä ja variaatiota, sekä sitä, lisääkö pitkä toinen metatarsaali Freibergin taudin kehittymisen riskiä. Yleisesti vakiintunutta menetelmää metatarsaalien pituuksien mittaamiseen ei ole, joten tutkimuksen alussa vertailtiin kolmea toisistaan poikkeavaa menetelmää; Hardy-Clapham, Maestron ja Coughlinin menetelmiä. Lukijan sisäisen ja lukijoiden välisen toistettavuuden mittauksissa yhtäpitävimmäksi ja siten lopulliseksi luokitusmenetelmäksi valikoitui Coughlinin menetelmä, jolla mittaukset aineistoon suoritettiin. Tutkimus osoitti, että Freibergin tauti on suomalaisessa väestössä hyvin harvinainen, ja ettei toisen metatarsaalin pituus korreloi Freibergin taudin esiintyvyyden kanssa

A framework for overall sustainability assessment of local small-scale energy production - demonstration of an approach

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Unitarity constraint for threshold coherent pion photoproduction on the deuteron and chiral perturbation theory

The contribution of the two-step process gamma + d -> p + n -> pi0 + d to the imaginary part of the amplitude for coherent pion production on the deuteron is calculated exploiting unitarity constraints. The result shows that this absorptive process is not negligible and has to be considered in an extraction of the elementary neutron production amplitude from the gamma + d -> pi0 + d cross section at threshold. In addition, it is argued that a consistent calculation of gamma + d -> pi0 + d in baryon chiral perturbation theory beyond next-to-leading order requires the inclusion of this absorptive process.Comment: 11 pages revtex including 2 postscript figure

Re-analysis of the Levanluhta skeletal material : Sex and stature estimation of individuals in an Iron Age water burial in Finland

Levanluhta, an Iron Age water burial site in Finland, and its material consisting of commingled skeletal remains and artifacts, has been studied by several researchers over the past 100 years, resulting in multiple interpretations of the people and the site. Previous skeletal analyses have concluded that the majority of the individuals represented in the remains were females and children and were of relatively short stature, so possibly nutritionally deprived. This study re-analyzed the commingled adult human remains with updated methods. The methods applied in this study to estimate sex and stature were based on more representative European reference samples than the previously applied methods. The methods included morphology, osteometrics, and computed tomography (CT) scans. Our results indicated that depending on the reference data, the majority of the individual adult bones including os coxae (73%, n = 45) and long bones (humerus 83%-89%, n = 52; radius 72%-89%, n = 47; ulna 50%-65%, n = 58; femur 92%-100%, n = 25; tibia 77%-85%, n = 26) were classified as females based on their size and morphology. The cross-sectional bone properties of humerii, femora, and tibiae visualized using CT scanning also supported these findings. However, the cranial morphology did not show as clear female-biased sex ratio as other methods (42% females, 33% males, 24% undetermined, n = 33). In females, the mean stature based on the tibia (155.3 cm, n = 10) was within the range of the coeval European females and did not necessarily indicate nutritional deprivation, which is in line with previously published stable isotope findings from the site. The mean stature based on the tibia suggested that the Levanluhta males were short (164.0 cm, n = 3), but final interpretations were limited due to the small number of male individuals. The current study affirmed that the Levanluhta skeletal assemblage was female biased and gave new insights into interpretation of the stature.Peer reviewe