A Search for Dark Higgs Bosons

Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb-1 of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the Standard Model-dark sector mixing angle and the dark sector coupling constant.Comment: 7 pages, 5 postscript figures, published version with improved plots for b/w printin

B0 meson decays to rho0 K*0, f0 K*0, and rho-K*+, including higher K* resonances

We present branching fraction measurements for the decays B0 -> rho0 K*0, B0 -> f0 K*0, and B0 -> rho- K*+, where K* is an S-wave (K pi)_0* or a K*(892) meson; we also measure B0 -> f0 K_2*(1430)^0. For the K*(892) channels, we report measurements of longitudinal polarization fractions (for rho final states) and direct CP-violation asymmetries. These results are obtained from a sample of (471.0 +/- 2.8) x 10^6 BBbar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+ e- collider at the SLAC National Accelerator Laboratory. We observe rho0 K*(892)^0, rho0 (K pi)_0^{*0}, f0 K*(892)^0, and rho- K*(892)+ with greater than 5 sigma significance, including systematics. We report first evidence for f0 (K pi)_0^{*0} and f0 K_2*(1430)^0, and place an upper limit on rho- (K pi)_0^{*+}. Our results in the K*(892) channels are consistent with no direct CP-violation.Comment: 17 pages, 6 postscript figures, submitted to Phys. Rev.

Measurement of the t(t)over-bar production cross section in pp collisions at √s=7 TeV with lepton plus jets final states

This is the pre-print version of the Article. The official published can be accessed from the link below. Copyright @ 2013 ElsevierA measurement of the tt¯ production cross section in pp collisions at √s=7 TeV is presented. The results are based on data corresponding to an integrated luminosity of 2.3 fb−1 collected by the CMS detector at the LHC. Selected events are required to have one isolated, high transverse momentum electron or muon, large missing transverse energy, and hadronic jets, at least one of which must be consistent with having originated from a b quark. The measured cross section is 158.1 ± 2.1 (stat.) ± 10.2(syst.) ± 3.5 (lum.) pb, in agreement with standard model predictions.This study is funded by the: BMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MEYS (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Republic of Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MSI (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MON, RosAtom, RAS and RFBR (Russia); MSTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEPCenter, IPST and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA)

Measurement of B(B)over-bar angular correlations based on secondary vertex reconstruction at √s =7 TeV

This is the pre-print version of the Published Article, which can be accessed from the link below - Copyright @ 2011 Springer VerlagA measurement of the angular correlations between beauty and anti-beauty hadrons (B B-bar) produced in pp collisions at a centre-of-mass energy of 7 TeV at the CERN LHC is presented, probing for the first time the region of small angular separation. The B hadrons are identified by the presence of displaced secondary vertices from their decays. The B hadron angular separation is reconstructed from the decay vertices and the primary-interaction vertex. The differential B B-bar production cross section, measured from a data sample collected by CMS and corresponding to an integrated luminosity of 3.1 inverse picobarns, shows that a sizable fraction of the B B-bar pairs are produced with small opening angles. These studies provide a test of QCD and further insight into the dynamics of b b-bar production

The Case On Assessment Of Spilled Oil With Mixed Free Product In Seoul

The purpose of this study is to assess sources of contamination by analyzing the free product and oil compounds in groundwater near the Subway Station, located adjacent to the Yongsan Garrison in Seoul, Republic of Korea. All of the samples collected twice were groundwater and free product in a monitoring well. Analysis items are TPH fingerprinting, pristine/phytane ratio, alkylbenzene pattern, PAH&alkyl PAH, antioxidant, icing inhibitor, PIANO, element(C, N, H), and sulfur. Using ratio of pristine/phytane, we were able to distinguished fuel type between kerosene and JP-8 samples, which was impossible by GC/FID pattern. Alkyl benzene pattern was very effective in distinguishing between JP-8 and kerosene. It is very important that 2,4-dimethyl-6-tert-butyl phenol, an antioxidant used only for JP-8, was detected in free product samples. The concentration of sulfur in kerosene fuel is much lower than that of JP-8, and the total contents of sulfur in environmental samples can be used to differentiate the fuel type of spilled oil between kerosene and JP-8. In conclusion, according to the result of a variety of analytical methods to find the source of spilled fuel, it had been found that the fuel type detected in the tunnel of subway station and monitoring wells outside of Yongsan Garrison and the monitoring wells inside of Yongsan Garrison are the same

Search for CP violation in the decay τ^{-}→π^{-}K_{s}^{0}(≥Oπ^{0})ν_{τ}

We report a search for CP violation in the decay τ-→π-KS0(≥0π0)ντ using a data set of 437×106 τ-lepton pairs, corresponding to an integrated luminosity of 476  fb-1, collected with the BABAR detector at the PEP-II asymmetric-energy e+e- storage rings. The CP-violating decay-rate asymmetry is determined to be (-0.36±0.23±0.11)% approximately 2.8 standard deviations from the standard model prediction of (0.36±0.01)%

Search for excited leptons in pp collisions at root s=7 TeV

Results are presented of a search for compositeness in electrons and muons using a data sample of pp collisions at a center-of-mass energy root s = 7 TeV collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 5.0 fb(-1). Excited leptons (l*) are assumed to be produced via contact interactions in conjunction with a standard model lepton and to decay via l* -> l gamma, yielding a final state with two energetic leptons and a photon. The number of events observed in data is consistent with that expected from the standard model. The 95% confidence upper limits for the cross section for the production and decay of excited electrons (muons), with masses ranging from 0.6 to 2 TeV, are 1.48 to 1.24 fb (1.31 to 1.11 fb). Excited leptons with masses below 1.9 TeV are excluded for the case where the contact interaction scale equals the excited lepton mass. The limits on the cross sections are the most stringent ones published to date. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved

Measurement of the t(t)over-bar production cross section in pp collisions at root s=7 TeV with lepton plus jets final states

A measurement of the a production cross section in pp collisions at root s = 7 TeV is presented. The results are based on data corresponding to an integrated luminosity of 2.3 fb(-1) collected by the CMS detector at the LHC. Selected events are required to have one isolated, high transverse momentum electron or muon, large missing transverse energy, and hadronic jets, at least one of which must be consistent with having originated from a b quark. The measured cross section is 158.1 +/- 2.1 (stat.) +/- 10.2 (syst.) +/- 3.5 (lum.) pb, in agreement with standard model predictions. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved

Angular analysis and branching fraction measurement of the decay B-0 -> K*(0)mu(+)mu(-)

The angular distributions and the differential branching fraction of the decay B-0 -> K*(892)(0)mu(+)mu(-) are studied using a data sample corresponding to an integrated luminosity of 5.2 fb(-1) collected with the CMS detector at the LHC in pp collisions at root s = 7 TeV. From more than 400 signal decays, the forward-backward asymmetry of the muons, the K*(892)(0) longitudinal polarization fraction, and the differential branching fraction are determined as a function of the square of the dimuon invariant mass. The measurements are in good agreement with standard model predictions. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved