A measurement of the first four moments of the hadronic mass distribution in
B->Xc lv decays is presented for minimum lepton momenta varying between 0.9 and
1.6 GeV, using data recorded with the ...BaBar detector. Furthermore, a
measurement of the inclusive electron energy spectrum for semileptonic B decays
together with a measurement of its first, second and third moments for minimum
electron energies between 0.6 and 1.5 GeV is reported. We determine the
inclusive B->Xc lv branching fraction, B_clv, the CKM matrix element |V_cb|,
and other heavy-quark parameters from a simultaneous fit to the measured
moments.
Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, neutralino_1, assumed here to be the LSP and thus the Dark Matter ...(DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly-degenerate next-to-lightest supersymmetric particle (NLSP) such as the lighter stau (stau_1), stop (stop_1) or chargino (chargino_1), resonant annihilation via direct-channel heavy Higgs bosons H/A, the light Higgs boson h or the Z boson, and enhanced annihilation via a larger Higgsino component of the LSP in the focus-point region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2 and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the stau_1 coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be explored at the LHC via searches for missing E_T events and long-lived charged particles, whereas their H/A funnel, focus-point and chargino_1 coannihilation regions can largely be explored by the LZ and Darwin DM direct detection experiments. We find that the dominant DM mechanism in our pMSSM10 analysis is chargino_1 coannihilation: {parts of its parameter space can be explored by the LHC, and a larger portion by future direct DM searches.
The pMSSM10 after LHC Run 1 de Vries, K J; Bagnaschi, E A; Buchmueller, O ...
arXiv.org,
04/2015
Paper, Journal Article
Odprti dostop
We present a frequentist analysis of the parameter space of the pMSSM10, in which the following 10 soft SUSY-breaking parameters are specified independently at the mean scalar top mass scale Msusy = ...SqrtM_stop1 M_stop2: the gaugino masses M_{1,2,3}, the 1st-and 2nd-generation squark masses M_squ1 = M_squ2, the third-generation squark mass M_squ3, a common slepton mass M_slep and a common trilinear mixing parameter A, the Higgs mixing parameter mu, the pseudoscalar Higgs mass M_A and tan beta. We use the MultiNest sampling algorithm with 1.2 x 10^9 points to sample the pMSSM10 parameter space. A dedicated study shows that the sensitivities to strongly-interacting SUSY masses of ATLAS and CMS searches for jets, leptons + MET signals depend only weakly on many of the other pMSSM10 parameters. With the aid of the Atom and Scorpion codes, we also implement the LHC searches for EW-interacting sparticles and light stops, so as to confront the pMSSM10 parameter space with all relevant SUSY searches. In addition, our analysis includes Higgs mass and rate measurements using the HiggsSignals code, SUSY Higgs exclusion bounds, the measurements B-physics observables, EW precision observables, the CDM density and searches for spin-independent DM scattering. We show that the pMSSM10 is able to provide a SUSY interpretation of (g-2)_mu, unlike the CMSSM, NUHM1 and NUHM2. As a result, we find (omitting Higgs rates) that the minimum chi^2/dof = 20.5/18 in the pMSSM10, corresponding to a chi^2 probability of 30.8 %, to be compared with chi^2/dof = 32.8/24 (31.1/23) (30.3/22) in the CMSSM (NUHM1) (NUHM2). We display 1-dimensional likelihood functions for SUSY masses, and show that they may be significantly lighter in the pMSSM10 than in the CMSSM, NUHM1 and NUHM2. We discuss the discovery potential of future LHC runs, e+e- colliders and direct detection experiments.
The NUHM2 after LHC Run 1 Buchmueller, O; Cavanaugh, R; Citron, M ...
arXiv.org,
08/2014
Paper, Journal Article
Odprti dostop
We 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, \(m^2_{H_{u,d}}\), vary ...independently from the universal soft SUSY-breaking contributions \(m^2_0\) to the masses of squarks and sleptons. Our analysis uses the MultiNest sampling algorithm with over \(4 \times 10^8\) points to sample the NUHM2 parameter space. It includes the ATLAS and CMS Higgs mass measurements as well as their searches for supersymmetric jets + MET signals using the full LHC Run~1 data, the measurements of \(B_s \to \mu^+ \mu^-\) 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 for squarks and sleptons, \(m_0^2 < 0\), as well as \(m^2_{H_u} < m^2_{H_d} < 0\). The tension present in the CMSSM and NUHM1 between the supersymmetric interpretation of \(g_\mu - 2\) and the absence to date of SUSY at the LHC is not significantly alleviated in the NUHM2. We find that the minimum \(\chi^2 = 32.5\) with 21 degrees of freedom (dof) in the NUHM2, to be compared with \(\chi^2/{\rm dof} = 35.0/23\) in the CMSSM, and \(\chi^2/{\rm dof} = 32.7/22\) 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.
A measurement of the first four moments of the hadronic mass distribution in B->Xc lv decays is presented for minimum lepton momenta varying between 0.9 and 1.6 GeV, using data recorded with the ...BaBar detector. Furthermore, a measurement of the inclusive electron energy spectrum for semileptonic B decays together with a measurement of its first, second and third moments for minimum electron energies between 0.6 and 1.5 GeV is reported. We determine the inclusive B->Xc lv branching fraction, B_clv, the CKM matrix element |V_cb|, and other heavy-quark parameters from a simultaneous fit to the measured moments.
In view of the imminent start of the LHC experimental programme, we use the available indirect experimental and cosmological information to estimate the likely range of parameters of the constrained ...minimal supersymmetric extension of the Standard Model (CMSSM), using a Markov-chain Monte Carlo (MCMC) technique to sample the parameter space. The 95% confidence-level area in the (m_0, m_1/2) plane of the CMSSM lies largely within the region that could be explored with 1/fb of integrated luminosity at 14 TeV, and much of the 68% confidence-level area lies within the region that could be explored with 50/pb of integrated luminosity at 10 TeV. A same-sign dilepton signal could well be visible in most of the 68% confidence-level area with 1/fb of integrated luminosity at 14 TeV. We discuss the sensitivities of the preferred ranges to variations in the most relevant indirect experimental and cosmological constraints and also to deviations from the universality of the supersymmetry-breaking contributions to the masses of the Higgs bosons.
This article reports world averages for measurements of b-hadron and c-hadron properties obtained by the Heavy Flavor Averaging Group (HFAG) using the results available at the end of 2007. For the ...averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, and parameters of semileptonic decays.
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