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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.


Papers
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Albert M. Sirunyan1, Armen Tumasyan1, Wolfgang Adam, Federico Ambrogi  +2227 moreInstitutions (143)
TL;DR: In this paper, a search for resonance-like structures in the Bs0π± invariant mass spectrum was performed using proton-proton collision data collected by the CMS experiment at the LHC at s=8.7
Abstract: A search for resonancelike structures in the Bs0π± invariant mass spectrum is performed using proton-proton collision data collected by the CMS experiment at the LHC at s=8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The Bs0 mesons are reconstructed in the decay chain Bs0→J/ψϕ, with J/ψ→μ+μ- and ϕ→K+K-. The Bs0π± invariant mass distribution shows no statistically significant peaks for different selection requirements on the reconstructed Bs0 and π± candidates. Upper limits are set on the relative production rates of the X(5568) and Bs0 states times the branching fraction of the decay X(5568)±→Bs0π±. In addition, upper limits are obtained as a function of the mass and the natural width of possible exotic states decaying into Bs0π±.

52 citations

Journal ArticleDOI
TL;DR: A search for the Higgs boson decaying to two oppositely charged muons is presented using data recorded by the CMS experiment at the CERN LHC in 2016, and the background-only expected upper limit improves to 2.2 times the standard model value with a standard model expected significance of 1.0 standard deviation.
Abstract: A search for the Higgs boson decaying to two oppositely charged muons is presented using data recorded by the CMS experiment at the CERN LHC in 2016 at a center-of-mass energy s=13 TeV, corresponding to an integrated luminosity of 35.9 fb-1. Data are found to be compatible with the predicted background. For a Higgs boson with a mass of 125.09 GeV, the 95% confidence level observed (background-only expected) upper limit on the production cross section times the branching fraction to a pair of muons is found to be 3.0 (2.5) times the standard model expectation. In combination with data recorded at center-of-mass energies s=7 and 8 TeV, the background-only expected upper limit improves to 2.2 times the standard model value with a standard model expected significance of 1.0 standard deviation. The corresponding observed upper limit is 2.9 with an observed significance of 0.9 standard deviation. This corresponds to an observed upper limit on the standard model Higgs boson branching fraction to muons of 6.4×10-4 and to an observed signal strength of 1.0±1.0(stat)±0.1(syst).

51 citations

Journal ArticleDOI
TL;DR: The epidermal growth factor receptor/ligand system appears to be involved in tumor development and tumor progression of colorectal carcinomas, with prognostic implication especially in patients with invasive rectal cancer.
Abstract: PURPOSE: The epidermal growth factor receptor and its various ligands (epidermal growth factor, transforming growth factor-alpha, amphiregulin, heparin-binding epidermal growth factor, heregulin, and betacellulin) have been implicated in growth and regeneration of intestinal mucosa and might be related to the development and progression of gastrointestinal tumors. Although some studies have investigated levels of epidermal growth factor receptor by radioligand binding studies, none of them have further analyzed these levels in patients with rectal cancer and investigated their prognostic value. METHODS: We quantitatively determined tumor epidermal growth factor receptor levels in 38 patients with colorectal cancer compared with adjacent normal mucosa by iodine-125–labeled epidermal growth factor binding studies and Scatchard analysis. Patients were followed up for 49.5 ± 32.2 (range, 2–120) months. RESULTS: Epidermal growth factor receptor capacity was increased in invasive colorectal carcinomas according to T classification (P < 0.001), tumors with lymph node infiltration (P = 0.038), and advanced International Union Against Cancer stage (P < 0.001). Survival of colorectal cancer was reduced in patients with advanced International Union Against Cancer stage (P < 0.001), tumors with positive lymph nodes (P < 0.001), and tumors with elevated epidermal growth factor receptor levels (P = 0.024). In rectal cancer patients, poor prognosis was associated with advanced International Union Against Cancer stage (P = 0.029), tumors with lymph node infiltration (P = 0.040), and increased epidermal growth factor receptor levels (P = 0.002). Multivariate Cox regression analysis indicated that elevated levels of epidermal growth factor receptor were an independent predictor of reduced survival in patients with rectal cancer (P = 0.005). CONCLUSION: The epidermal growth factor receptor/ligand system appears to be involved in tumor development and tumor progression of colorectal carcinomas, with prognostic implication especially in patients with invasive rectal carcinomas. These patients might take advantage of therapies that specifically block epidermal growth factor receptor–mediated signal transduction.

51 citations

Journal ArticleDOI
TL;DR: In this article, a measurement of the b-hadron production cross section in proton-proton collisions at 7 TeV was presented, corresponding to 85 inverse nanobarns, using a low-threshold single-muon trigger.
Abstract: A measurement of the b-hadron production cross section in proton-proton collisions at sqrt(s)=7 TeV is presented. The dataset, corresponding to 85 inverse nanobarns, was recorded with the CMS experiment at the LHC using a low-threshold single-muon trigger. Events are selected by the presence of a muon with transverse momentum greater than 6 GeV with respect to the beam direction and pseudorapidity less than 2.1. The transverse momentum of the muon with respect to the closest jet discriminates events containing b hadrons from background. The inclusive b-hadron production cross section is presented as a function of muon transverse momentum and pseudorapidity. The measured total cross section in the kinematic acceptance is sigma(pp to b+X to mu + X') =1.32 +/- 0.01 (stat) +/- 0.30 (syst) +/- 0.15 (lumi) microbarns.

51 citations

Journal ArticleDOI
TL;DR: In this paper, the results of a search for the bottomonium counterpart, denoted as Xb, of the exotic charmonium state X(3872), were presented.

51 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
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 …

33,785 citations

Journal ArticleDOI
01 Apr 1988-Nature
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
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

9,929 citations

01 Jan 2014
TL;DR: 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.
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.

9,618 citations

Journal ArticleDOI
Georges Aad1, T. Abajyan2, Brad Abbott3, Jalal Abdallah4  +2964 moreInstitutions (200)
TL;DR: In this article, a search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7×10−9.

9,282 citations