Supersymmetry at the Tevatron ?

These lectures contain an introduction to the search for supersymmetry at hadron colliders. The Tevatron is one of high-energy physics most sophisticated tools. The high center-of-mass energy of its proton-antiproton collisions makes it an ideal place to search for physics beyond the Standard Model, such as supersymmetry. Two experiments, CDF and D\O, completed a long data taking period in summer of 1995, yielding over $100 p b^{-1}$ of proton-- antiproton interactions. The data recorded by the experiments are still being analysed. The lectures outline the strategies in the search for supersymmetry at the Tevatron and examine the major analyses in detail. Results obtained by the two experiments are included where available.Comment: 40 pages, 13 figure

Search for Higgs and New Phenomena at Colliders

The present status of searches for the Higgs boson(s) and new phenomena is reviewed. The focus is on analyses and results from the current runs of the HERA and Tevatron experiments. The LEP experiments have released their final combined MSSM Higgs results for this conference. Also included are results from sensitivity studies of the LHC experiments and lepton flavour violating searches from the B factories, KEKB and PEP-II.Comment: XXII International Symposium on Lepton-Photon Interactions at High Energy (11 pages, 16 figures, 2 tables

Identifikation eines dualen mesokortikolimbischen Dopaminsystems mit selektiven axonalen Projektionen in der adulten Maus (Mus musculus L.)

Dopaminerge (DA) Neurone sind im Mittelhirn hauptsächlich in zwei Nuklei lokalisiert: in der Substantia nigra (SN, A9) und Area tegmentalis ventralis (VTA, A10). Währene DA SN Neurone das dorsale Striatum innervieren, projizieren die DA VTA Neurone in kortikolimbische Hirnareale (u.a. präfrontaler Kortex (PFC), basolaterale Amygdala (BLA), Nukleus Accumbens (NAc) core/shell). Die eingehend charakterisierten klassischen mesostriatalen DA Neurone sind essentiell für die Ausführung von Willkürbewegungen und für die Vermittlung prädiktiver Belohnungssignale. Dagegen sind die elektrophysiologischen Eigenschaften der DA Neurone, die durch eine vornehmlich tonische Dopaminfreisetzung in kortikolimbischen Hirnarealen beispielsweise die Salienz appetitiver und aversiver Stimuli, sowie kognitive (working memory) und emotionale Funktionen vermitteln, weitgehend unbekannt. Im Rahmen der vorliegenden Arbeit wurde daher selektives retrogrades Tracing in Kombination mit elektrophysiologischen und immunhistochemischen Methoden durchgeführt, um die anatomischen, morphologischen und funktionellen Eigenschaften mesokortikolimbischer DA Neurone im Vergleich zu den klassischen mesostriatalen DA Neuronen in adulten C57Bl/6 Mäusen zu analysieren. In der vorliegenden Arbeit wurde herausgefunden, dass das mesokortikolimbische DA System anatomisch, molekular und funktionell von zwei unterschiedlichen Phänotypen DA Neurone gebildet wird. Dabei konnte neben dem klassischen Typ, erstmals die Existenz eines weiteren DA Phänotyps mit unkonventionellen elektrophysiologischen Eigenschaften beschrieben werden. Es konnte gezeigt werden, dass DA Neurone, die den PFC, die BLA und die core Subregion des NAc innervieren vor allem in der medialen VTA des intermediären Mittelhirn lokalisiert waren. Dagegen waren die DA Nervenzellen, die in den lateralen shell des NAc sowie in das dorsolaterale Striatum projizieren und präferentiell in der lateralen VTA in der SN und in der Area retrorubralis (A8) lokalisiert. Die topographische Dualität des mesokortikolimbischen DA Systems konnte auch in einer differentiellen Proteinexpression wiedergefunden werden. Mesokortikale, mesoamygdaläre und mesolimbische core DA Neurone waren im Vergleich zu mesolimbischen shell und mesostriatalen DA Neuronen durch eine geringe Expression des Dopamintransporters (DAT) gekennzeichnet. Ferner konnte gezeigt werden, dass das Markerprotein Calbindin nur bedingt für die Differenzierung des DA Mittelhirnsystems geeignet ist. Die maximale Feuerungsrate der mesostriatalen und mesolimbischen shell DA Neurone lag stets unterhalb von 10 Hz und war ebenso wie weitere elektophysiologische Parameter (Aktionspotentialdauer, Nachhyperpolarisation) konsistent mit den in der Literatur beschriebenen klassischen DA SN Neuronen in vivo und in vitro. Im unterschwelligen Bereich eines Aktionspotentials war eine schnelle Inaktivierung eines spannungabhängigen Kaliumauswärtsstroms (A-Strom) charakteristisch. Bei Injektion hyperpolarisierender Ströme wiesen diese Zellen eine für DA Neurone typische zeitabhängige Verringerung des korrespondierenden Membranpotentials auf (sag Amplitude, vermittelt über HCN Kanälen). Die Applikation von 100 µM Dopamin führte zu einer über somatodendritische D2 Autorezeptoren vermittelten kompletten und persistierenden Inhibition der Spontanaktivität. Im Gegensatz hierzu waren mesokortikale, mesoamygdaläre und mesolimbische core DA Neurone durch unkonventionelle elektrophysiologische Eigenschaften gekennzeichnet. Diese Zellen konnten ungewöhnlich hohe maximale Feuerungsraten von etwa 20-30 Hz erreichen. Die Aktionspotentialdauer war signifikant länger und die Amplitude der Nachhyperpolarisation signifkant niedriger. Weiterhin gab es keine Hinweise auf das Vorhandensein von HCN Kanälen und die Inaktivierung des A-Typ Kanals war signifikant langsamer. Die Applikation von Dopamin führte entweder zu keiner (mesokortikale DA Neurone) oder nur zu einer transienten (mesoamygdaläre, mesolimbische core DA Neurone) Inhibition der Spontanaktivität. Ferner konnte gezeigt werden, dass GIRK2 Kanäle, die durch somatodendritische D2 Autorezeptoren aktiviert werden, signifikant niedriger in den unkonventionellen DA Neuronen exprimiert sind. Der funktionelle Dualismus des mesokortikolimbischen DA System konnte anhand einer hierarchischen Clusteranalyse statistisch bestätigt werden. Die unkonventionellen elektrophysiologischen Eigenschaften machen die mesokortikalen, mesoamygdalären und mesolimbischen core DA Neuronen zu geeigneten Kandidaten für die Vermittlung tonischer Dopaminfreisetzung in vivo und haben somit eine wichtige Funktion bei der Vermittlung kognitiver, motivationaler und emotionaler Fähigkeiten. Der in der vorliegenden Arbeit vorgestellte anatomische, morphologische, funktionelle und molekulare Dualismus des mesokortikolimbischen DA Systems liefert die zelluläre Basis für die selektive Modulation DA Subpopulationen und ist somit von besonderer Bedeutung für die Entwicklung neuer spezifischer, nebenwirkungsarmer Arzneimittel in der Therapie neurologischer Erkrankungen wie beispielsweise Schizophrenie, Morbus Parkinson und ADHS

Input-specific control of reward and aversion in the ventral tegmental area

Ventral tegmental area (VTA) dopamine neurons have important roles in adaptive and pathological brain functions related to reward and motivation. However, it is unknown whether subpopulations of VTA dopamine neurons participate in distinct circuits that encode different motivational signatures, and whether inputs to the VTA differentially modulate such circuits. Here we show that, because of differences in synaptic connectivity, activation of inputs to the VTA from the laterodorsal tegmentum and the lateral habenula elicit reward and aversion in mice, respectively. Laterodorsal tegmentum neurons preferentially synapse on dopamine neurons projecting to the nucleus accumbens lateral shell, whereas lateral habenula neurons synapse primarily on dopamine neurons projecting to the medial prefrontal cortex as well as on GABAergic (γ-aminobutyric-acid-containing) neurons in the rostromedial tegmental nucleus. These results establish that distinct VTA circuits generate reward and aversion, and thereby provide a new framework for understanding the circuit basis of adaptive and pathological motivated behaviours.National Institutes of Health (U.S.) (Grant NIH NS069375)JPB FoundationNational Institute of Mental Health (U.S.

Different Neutralization Profiles After Primary SARS-CoV-2 Omicron BA.1 and BA.2 Infections

Background and MethodsThe SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) Omicron (B.1.1.529) variant is the antigenically most distinct variant to date. As the heavily mutated spike protein enables neutralization escape, we studied serum-neutralizing activities of naïve and vaccinated individuals after Omicron BA.1 or BA.2 sub-lineage infections in live virus neutralization tests with Omicron BA.1, Omicron BA.2, wildtype (WT, B1.1), and Delta (B.1.617.2) strains. Serum samples obtained after WT infections and three-dose mRNA vaccinations with and without prior infection were included as controls.ResultsPrimary BA.1 infections yielded reduced neutralizing antibody levels against WT, Delta, and Omicron BA.2, while samples from BA.2-infected individuals showed almost no cross-neutralization against the other variants. Serum neutralization of Omicron BA.1 and BA.2 variants was detectable after three-dose mRNA vaccinations, but with reduced titers. Vaccination-breakthrough infections with either Omicron BA.1 or BA.2, however, generated equal cross-neutralizing antibody levels against all SARS-CoV-2 variants tested.ConclusionsOur study demonstrates that although Omicron variants are able to enhance cross-neutralizing antibody levels in pre-immune individuals, primary infections with BA.1 or BA.2 induced mostly variant-specific neutralizing antibodies, emphasizing the differently shaped humoral immunity induced by the two Omicron variants. These data thus contribute substantially to the understanding of antibody responses induced by primary Omicron infections or multiple exposures to different SARS-CoV-2 variants and are of particular importance for developing vaccination strategies in the light of future emerging variants

HEP Science Network Requirements--Final Report

The Energy Sciences Network (ESnet) is the primary provider of network connectivity for the US Department of Energy Office of Science, the single largest supporter of basic research in the physical sciences in the United States. In support of the Office of Science programs, ESnet regularly updates and refreshes its understanding of the networking requirements of the instruments, facilities, scientists, and science programs that it serves. This focus has helped ESnet to be a highly successful enabler of scientific discovery for over 20 years. In August 2009 ESnet and the Office of High Energy Physics (HEP), of the DOE Office of Science, organized a workshop to characterize the networking requirements of the programs funded by HEP. The International HEP community has been a leader in data intensive science from the beginning. HEP data sets have historically been the largest of all scientific data sets, and the communty of interest the most distributed. The HEP community was also the first to embrace Grid technologies. The requirements identified at the workshop are summarized below, and described in more detail in the case studies and the Findings section: (1) There will be more LHC Tier-3 sites than orginally thought, and likely more Tier-2 to Tier-2 traffic than was envisioned. It it not yet known what the impact of this will be on ESnet, but we will need to keep an eye on this traffic. (2) The LHC Tier-1 sites (BNL and FNAL) predict the need for 40-50 Gbps of data movement capacity in 2-5 years, and 100-200 Gbps in 5-10 years for HEP program related traffic. Other key HEP sites include LHC Tier-2 and Tier-3 sites, many of which are located at universities. To support the LHC, ESnet must continue its collaborations with university and international networks. (3) While in all cases the deployed 'raw' network bandwidth must exceed the user requirements in order to meet the data transfer and reliability requirements, network engineering for trans-Atlantic connectivity is more complex than network engineering for intra-US connectivity. This is because transoceanic circuits have lower reliability and longer repair times when compared with land-based circuits. Therefore, trans-Atlantic connectivity requires greater deployed bandwidth and diversity to ensure reliability and service continuity of the user-level required data transfer rates. (4) Trans-Atlantic traffic load and patterns must be monitored, and projections adjusted if necessary. There is currently a shutdown planned for the LHC in 2012 that may affect projections of trans-Atlantic bandwidth requirements. (5) There is a significant need for network tuning and troubleshooting during the establishment of new LHC Tier-2 and Tier-3 facilities. ESnet will work with the HEP community to help new sites effectively use the network. (6) SLAC is building the CCD camera for the LSST. This project will require significant bandwidth (up to 30Gbps) to NCSA over the next few years. (7) The accelerator modeling program at SLAC could require the movement of 1PB simulation data sets from the Leadership Computing Facilities at Argonne and Oak Ridge to SLAC. The data sets would need to be moved overnight, and moving 1PB in eight hours requires more than 300Gbps of throughput. This requirement is dependent on the deployment of analysis capabilities at SLAC, and is about five years away. (8) It is difficult to achieve high data transfer throughput to sites in China. Projects that need to transfer data in or out of China are encouraged to deploy test and measurement infrastructure (e.g. perfSONAR) and allow time for performance tuning

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV