Andreas Pfeiffer

Bio: Andreas Pfeiffer is an academic researcher from CERN. The author has contributed to research in topics: Large Hadron Collider & Lepton. The author has an hindex of 149, co-authored 1756 publications receiving 131080 citations. Previous affiliations of Andreas Pfeiffer include Heidelberg University & Paul Scherrer Institute.

Search for narrow resonances in dilepton mass spectra in pp collisions at s=7TeV

Abstract: A search for narrow, high-mass resonances decaying to electron or muon pairs has been performed using pp collision data collected at sqrt(s)=7 TeV by the CMS experiment in 2011. The data sample corresponds to an integrated luminosity of approximately 5 inverse femtobarns. The event yields observed in the signal regions are consistent with predictions of the standard model backgrounds, and upper limits on the cross section times branching fraction for a resonance decaying to dileptons are extracted from a shape analysis of the dilepton invariant mass distribution. The resulting mass limits at 95% confidence level are 2330 GeV for the Z' in the Sequential Standard Model, 2000 GeV for the superstring-inspired Z'(psi) resonance, 890 (540) GeV for the Stueckelberg extension Z'(St) with the mass parameter epsilon=0.06 (0.04), and 2140 (1810) GeV for Kaluza--Klein gravitons with the coupling parameter k/Mbar(Pl) of 0.10 (0.05). These limits are the most stringent to date.

Searches for supersymmetry using the M-T2 variable in hadronic events produced in pp collisions at 8 TeV

Abstract: Searches for supersymmetry (SUSY) are performed using a sample of hadronic events produced in 8 TeV pp collisions at the CERN LHC. The searches are based on the MT2 variable, which is a measure of the transverse momentum imbalance in an event. The data were collected with the CMS detector and correspond to an integrated luminosity of 19.5 inverse femtobarns. Two related searches are performed. The first is an inclusive search based on signal regions defined by the value of the MT2 variable, the hadronic energy in the event, the jet multiplicity, and the number of jets identified as originating from bottom quarks. The second is a search for a mass peak corresponding to a Higgs boson decaying to a bottom quark-antiquark pair, where the Higgs boson is produced as a decay product of a SUSY particle. For both searches, the principal backgrounds are evaluated with data control samples. No significant excess over the expected number of background events is observed, and exclusion limits on various SUSY models are derived.

Search for new phenomena with the $M_{\mathrm {T2}}$ variable in the all-hadronic final state produced in proton-proton collisions at $\sqrt{s} = 13$ $\,\text {TeV}

Abstract: A search for new phenomena is performed using events with jets and significant transverse momentum imbalance, as inferred through the $M_{\mathrm {T2}}$ variable The results are based on a sample of proton–proton collisions collected in 2016 at a center-of-mass energy of 13 $\,\text {TeV}$ with the CMS detector and corresponding to an integrated luminosity of 359 $\,\text {fb}^\text {-1}$ No excess event yield is observed above the predicted standard model background, and the results are interpreted as exclusion limits at 95% confidence level on the masses of predicted particles in a variety of simplified models of R-parity conserving supersymmetry Depending on the details of the model, 95% confidence level lower limits on the gluino (light-flavor squark) masses are placed up to 2025 (1550) $\,\text {GeV}$ Mass limits as high as 1070 (1175) $\,\text {GeV}$ are set on the masses of top (bottom) squarks Information is provided to enable re-interpretation of these results, including model-independent limits on the number of non-standard model events for a set of simplified, inclusive search regions

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Standards of Medical Care in Diabetes

Abstract: XI. STRATEGIES FOR IMPROVING DIABETES CARE D iabetes is a chronic illness that requires continuing medical care and patient self-management education to prevent acute complications and to reduce the risk of long-term complications. Diabetes care is complex and requires that many issues, beyond glycemic control, be addressed. A large body of evidence exists that supports a range of interventions to improve diabetes outcomes. These standards of care are intended to provide clinicians, patients, researchers, payors, and other interested individuals with the components of diabetes care, treatment goals, and tools to evaluate the quality of care. While individual preferences, comorbidities, and other patient factors may require modification of goals, targets that are desirable for most patients with diabetes are provided. These standards are not intended to preclude more extensive evaluation and management of the patient by other specialists as needed. For more detailed information, refer to Bode (Ed.): Medical Management of Type 1 Diabetes (1), Burant (Ed): Medical Management of Type 2 Diabetes (2), and Klingensmith (Ed): Intensive Diabetes Management (3). The recommendations included are diagnostic and therapeutic actions that are known or believed to favorably affect health outcomes of patients with diabetes. A grading system (Table 1), developed by the American Diabetes Association (ADA) and modeled after existing methods, was utilized to clarify and codify the evidence that forms the basis for the recommendations. The level of evidence that supports each recommendation is listed after each recommendation using the letters A, B, C, or E.