438 research outputs found
Implications of improved Higgs mass calculations for supersymmetric models
No full textBuchmueller, O. et al.We discuss the allowed parameter spaces of supersymmetric scenarios in light of improved Higgs mass predictions provided by FeynHiggs 2.10.0. The Higgs mass predictions combine Feynman-diagrammatic results with a resummation of leading and subleading logarithmic corrections from the stop/top sector, which yield a significant improvement in the region of large stop masses. Scans in the pMSSM parameter space show that, for given values of the soft supersymmetry-breaking parameters, the new logarithmic contributions beyond the two-loop order implemented in FeynHiggs tend to give larger values of the light CP-even Higgs mass, Mh , in the region of large stop masses than previous predictions that were based on a fixed-order Feynman-diagrammatic result, though the differences are generally consistent with the previous estimates of theoretical uncertainties. We re-analyse the parameter spaces of the CMSSM, NUHM1 and NUHM2, taking into account also the constraints from CMS and LHCb measurements of BR(Bs→μ+μ−) and ATLAS searches for /ET events using 20/fb of LHC data at 8 TeV. Within the CMSSM, the Higgs mass constraint disfavours tanβ≲10 , though not in the NUHM1 or NUHM2.The work of J.E. was supported in part by the London Centre for Terauniverse Studies (LCTS), using funding from the European Research Council via the Advanced Investigator Grant 267352. The work of K.A.O. was supported in part by DOE grant DEFG02- 94ER-40823 at the University ofMinnesota. The work of S.H. is supported in part by CICYT (Grant FPA 2010-22163C02-01) and by the Spanish MICINN’s Consolider-Ingenio 2010 Program under grant MultiDark CSD2009-00064. The work of G.W. was supported by the Collaborative Research Center SFB676 of the DFG, “Particles, Strings, and the early Universe”.Peer reviewe
Impact of CMS Silicon Tracker Misalignment on Track and Vertex Reconstruction
No full textinfo:eu-repo/semantics/publishe
Kinematische Rekonstruktion von WW-Ereignissen bei LEP2
No full textThis thesis describes the measurement of the W-boson mass from its decay products in semileptonic channels WW#->#e#nu#qq and WW#->##mu##nu#qq. The data sample used in this analysis was recorded with the detector ALEPH at a center-of-mass energy of #sq root#(s)=183 GeV during 1997. Selection and reconstruction algorithms of the semileptonic W decay are applied to define the samples. To improve the mass resolution, a constrained kinematic fit package has been developed. A fit of a Breit-Wigner function to the one-dimensional mass distribution after calibration leads to the result: M_W=80.21#+-#0.19(stat.)#+-#0.04(syst.) GeV/c"2. In order to improve the confidence into this measurement, seven additional mass extraction methods are developed and extensively tested for consistency. (orig.)Available from TIB Hannover: RR 1607(99-03) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
The CMSSM and NUHM1 after LHC Run 1
No full textWe analyze the impact of data from the full Run 1 of the LHC at 7 and 8 TeV on the CMSSM with μ > 0 and 0, incorporating the constraints imposed by other experiments such as precision electroweak measurements, flavour measurements, the cosmological density of cold dark matter and the direct search for the scattering of dark matter particles in the LUX experiment. We use the following results from the LHC experiments: ATLAS searches for events with
The NUHM2 after LHC Run 1
No full textWe make a frequentist analysis of the parameter space of the NUHM2, in which the soft supersymmetry (SUSY)-breaking contributions to the masses of the two Higgs multiplets, (Formula presented.), vary independently from the universal soft SUSY-breaking contributions (Formula presented.) to the masses of squarks and sleptons. Our analysis uses the MultiNest sampling algorithm with over (Formula presented.) points to sample the NUHM2 parameter space. It includes the ATLAS and CMS Higgs mass measurements as well as the ATLAS search for supersymmetric jets + (Formula presented.) signals using the full LHC Run 1 data, the measurements of (Formula presented.) by LHCb and CMS together with other B-physics observables, electroweak precision observables and the XENON100 and LUX searches for spin-independent dark-matter scattering. We find that the preferred regions of the NUHM2 parameter space have negative SUSY-breaking scalar masses squared at the GUT scale for squarks and sleptons, (Formula presented.). The tension present in the CMSSM and NUHM1 between the supersymmetric interpretation of (Formula presented.) and the absence to date of SUSY at the LHC is not significantly alleviated in the NUHM2. We find that the minimum (Formula presented.) with 21 degrees of freedom (dof) in the NUHM2, to be compared with (Formula presented.) in the CMSSM, and (Formula presented.) in the NUHM1. We find that the one-dimensional likelihood functions for sparticle masses and other observables are similar to those found previously in the CMSSM and NUHM1
Prediction for the Lightest Higgs Boson Mass in the CMSSM using Indirect Experimental Constraints
No full textMeasurements at low energies provide interesting indirect information about masses of particles that are (so far) too heavy to be produced directly. Motivated by recent progress in consistently and rigorously calculating electroweak precision observables and flavour related observables, we derive the *preferred* value for m_h in the Constrained Minimal Supersymmetric Standard Model (CMSSM), obtained from a fit taking into account electroweak precision data, flavour physics observables and the abundance of Cold Dark Matter. No restriction is imposed on m_h itself: the experimental bound from direct Higgs boson search at LEP is not included in the fit. A multi-parameter chi^2 is minimized with respect to the free parameters of the CMSSM, M_0, , A_0, tan\beta. A statistical comparison with the Standard Model fit to the electroweak precision data is made. The preferred value for the lightest Higgs boson mass in the CMSSM is found to be = (exp.)+-3(theo.) GeV/c^2, where the first uncertainty is experimental and the second uncertainty is theoretical. This value is compatible with the limit from direct Higgs boson search at LEP.Measurements at low energies provide interesting indirect information about masses of particles that are (so far) too heavy to be produced directly. Motivated by recent progress in consistently and rigorously calculating electroweak precision observables and flavour related observables, we derive the preferred value for mh in the Constrained Minimal Supersymmetric Standard Model (CMSSM), obtained from a fit taking into account electroweak precision data, flavour physics observables and the abundance of cold dark matter. No restriction is imposed on mh itself: the experimental bound from direct Higgs boson search at LEP is not included in the fit. A multi-parameter χ2 is minimized with respect to the free parameters of the CMSSM, M0 , M1/2 , A0 , tanβ . A statistical comparison with the Standard Model fit to the electroweak precision data is made. The preferred value for the lightest Higgs boson mass in the CMSSM is found to be mhCMSSM=110−10+8(exp.)±3(theo.) GeV/c2 , where the first uncertainty is experimental and the second uncertainty is theoretical. This value is compatible with the limit from direct Higgs boson search at LEP.Measurements at low energies provide interesting indirect information about masses of particles that are (so far) too heavy to be produced directly. Motivated by recent progress in consistently and rigorously calculating electroweak precision observables and flavour related observables, we derive the preferred value for m_h in the Constrained Minimal Supersymmetric Standard Model (CMSSM), obtained from a fit taking into account electroweak precision data, flavour physics observables and the abundance of Cold Dark Matter. No restriction is imposed on m_h itself: the experimental bound from direct Higgs boson search at LEP is not included in the fit. A multi-parameter chi^2 is minimized with respect to the free parameters of the CMSSM, M_0, M_1/2, A_0, tan(beta). A statistical comparison with the Standard Model fit to the electroweak precision data is made. The preferred value for the lightest Higgs boson mass in the CMSSM is found to be m_h^CMSSM = 110+8-10(exp.)+-3(theo.) GeV/c^2, where the first uncertainty is experimental and the second uncertainty is theoretical. This value is in agreement with the limit from direct Higgs boson search at LEP
Predictions for Supersymmetric Particle Masses using Indirect Experimental and Cosmological Constraints
No full textThe influence of supplementary health insurance on switching behaviour: evidence on Swiss data
No full textThis paper focuses on the switching behaviour of sickness fund enrolees in the Swiss health insurance system. Even though the new Federal Law on Social Health Insurance (LAMal) was implemented in 1996 to promote competition among health insurers in basic insurance, there still remains large premium variations within cantons. This indicates that competition has not been able so far to lead to a single price, and reveals some inertia among consumers who seem reluctant to switch to less expensive funds. We investigate one possible barrier to switching behaviour, namely the influence of the supplementary insurance. Our aim is to analyse two decisions (switching decision in basic insurance, subscription to supplementary insurance contracts). We use survey data on health plan choice and import some market data related to the sickness funds (number of enrollees, premiums). The decision to switch and the decision to subscribe to a supplementary contract are estimated both separately and jointly. The results suggest that holding a supplementary insurance contract substantially decreases the propensity to switch. However the impact of supplementary insurance is not significant when the individual assesses his/her health as "very good" ; to the contrary, holding a supplementary contract significantly reduces the propensity to switch when the indivual's subjective health status deteriorates. Futhermore, the switching decision is positively influenced by the expected gain of switching. In comparison with the range of the premium difference, the limitations to switch due to the supplementary insurance is moderate, though non negligible. As for the decision to subscribe a supplementary contract, the results show that the income level has a direct positive influence on the propensity to buy a supplementary insurance. Our results suggest that a major mechanism is going on in relation to supplementary insurance: holding a supplementary contract might stop individuals from switching when the individual thinks that she/he could be regarded as a bad risk due to the selection practices that are allowed in supplementary insurance markets. This result bears major policy implications concerning the regulation of basic and supplementary insurance markets.competition in health insurance ; switching behaviour ; premium convergence ; influence of supplementary insurance
Regulating Private Health Insurance in France : New Challenges for Employer-Based Complementary Health Insurance
No full textIn France, people obtain basic health insurance coverage through a public health insurance system. Although public coverage is comprehensive, substantial co-payments and deductibles are more and more required and individuals become increasingly dependant on private complementary health insurance, to be better reimbursed. In the context of strengthened constraints to control public health spending, the market for complementary cover is indeed likely to develop. This expansion has several implications for the regulation of private health insurance. Starting in the early 2000s, public policies have emphasized tools that directly motivate employers to provide group-insurance schemes. These include subsidies to employers for offering complulsory, supplementary coverage, and mandating social partners to negociate the implementation of health coverage in every compagny, whatever its size or activity. Such changes tend, to some extent, to "re-couple" health insurance with companies. This paper explores the implications of this experience for France.Private health care insurance, complementary employer-provided health insurance.
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