# PH-EP Articles

Последно добавени:
2017-01-09
11:13
 Observation of $B_{c}^{+} \rightarrow D^{0} K^{+}$ decays / LHCb Collaboration Using proton-proton collision data corresponding to an integrated luminosity of 3.0 fb$^{-1}$, recorded by the LHCb detector at centre-of-mass energies of 7 and 8 TeV, the $B_{c}^{+} \rightarrow D^{0} K^{+}$ decay is observed with a statistical significance of 5.1 standard deviations. By normalising to $B^{+} \rightarrow \bar{D}^{0} \pi^{+}$ decays, a measurement of the branching fraction multiplied by the production rates for $B_{c}^{+}$ relative to $B^{+}$ mesons in the LHCb acceptance is obtained, $R_{D^{0} K} = \frac{f_{c}}{f_{u}} \times \mathcal{B}(B_{c}^{+} \rightarrow D^{0} K^{+}) = (9.3\,^{+2.8}_{-2.5} \pm 0.6) \times 10^{-7}$ , where the first uncertainty is statistical and the second is systematic. [...] LHCB-PAPER-2016-058; CERN-EP-2016-314; arXiv:1701.01856; LHCB-PAPER-2016-058.- Geneva : CERN, 2017 - 15 p. - Published in : Phys. Rev. Lett. 118 (2017) 111803 APS Open Access article: PDF; Fulltext: LHCb-PAPER-2016-058-submitted - PDF; 10.1103_PhysRevLett.118.111803 - PDF; arXiv:1701.01856 - PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP;

2017-01-09
07:28
 Search for dark matter and unparticles in events with a Z boson and missing transverse momentum in proton-proton collisions at $\sqrt{s} =$ 13 TeV / CMS Collaboration A search for dark matter and unparticle production at the LHC has been performed using events containing two charged leptons (electrons or muons), consistent with the decay of a Z boson, and large missing transverse momentum. This study is based on data collected with the CMS detector in 2015, corresponding to an integrated luminosity of 2.3 fb$^{-1}$ of proton-proton collisions at the LHC, at a center-of-mass energy of 13 TeV. [...] CMS-EXO-16-010; CERN-EP-2016-309; arXiv:1701.02042; CMS-EXO-16-010.- Geneva : CERN, 2017 - 42 p. - Published in : J. High Energy Phys. 1703 (2017) 061 Fulltext: fermilab-pub-17-011-cms - PDF; cms-exo-16-010-arxiv - PDF; arXiv:1701.02042 - PDF; Springer Open Access article: PDF; External link: FERMILABPUB

2016-12-23
07:36
 Observation of $B_{c}^{+} \to J/\psi D^{(*)} K^{(*)}$ decays / LHCb Collaboration A search for the decays $B_c^+ \to J/\psi D^{(*)0} K^+$ and $B_c^+ \to J/\psi D^{(*)+} K^{*0}$ is performed with data collected at the LHCb experiment corresponding to an integrated luminosity of 3 fb$^{-1}$. The decays $B_c^+ \to J/\psi D^0 K^+$ and $B_c^+ \to J/\psi D^{*0} K^+$ are observed for the first time, while first evidence is reported for the $B_c^+ \to J/\psi D^{*+} K^{*0}$ and $B_c^+ \to J/\psi D^+ K^{*0}$ decays. [...] CERN-EP-2016-303; LHCB-PAPER-2016-055; arXiv:1612.07421.- Geneva : CERN, 2017 - 20 p. - Published in : Phys. Rev. 95 (2017) 032005 APS Open Access article: PDF; Fulltext: 10.1103_PhysRevD.95.032005 - PDF; arXiv:1612.07421 - PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP;

2016-12-21
07:51
 Measurement of the ratio of branching fractions and difference in $CP$ asymmetries of the decays $B^+\to J/\psi\pi^+$ and $B^+\to J/\psi K^+$ / LHCb Collaboration The ratio of branching fractions and the difference in $CP$ asymmetries of the decays $B^+\to J/\psi \pi^+$ and $B^+\to J/\psi K^+$ are measured using a data sample of $pp$ collisions collected by the LHCb experiment, corresponding to an integrated luminosity of $3~{{\,\mbox{fb}^{-1}}}$ at centre-of-mass energies of 7 and $8~\mathrm{\,Te\kern -0.1em V}$. The results are \begin{equation*} {\mathcal{B}(B^+\to J/\psi \pi^+)\over\mathcal{B}(B^+\to J/\psi K^+)}=(3.83\pm0.03\pm0.03)\times10^{-2}\,, \end{equation*} \begin{equation*} \mathcal{A}^{CP}(B^+\to J/\psi \pi^+)-\mathcal{A}^{CP}(B^+\to J/\psi K^+)=(1.82\pm0.86\pm0.14)\times10^{-2}, \end{equation*} where the first uncertainties are statistical and the second are systematic [...] LHCB-PAPER-2016-051; CERN-EP-2016-298; arXiv:1612.06116.- Geneva : CERN, 2017 - 18 p. - Published in : J. High Energy Phys. 1703 (2017) 036 Fulltext: PDF; Springer Open Access article: PDF;

2016-12-16
09:33
 Measurement of the $b$-quark production cross-section in 7 and 13 TeV $pp$ collisions / LHCb Collaboration Measurements of the cross-section for producing $b$ quarks in the reaction $pp \to b\overline{b}X$ are reported in $7$ and $13 TeV$ collisions at the LHC as a function of the pseudorapidity $\eta$ in the range $2<\eta<5$ covered by the acceptance of the LHCb experiment. The measurements are done using semileptonic decays of b-flavored hadrons decaying into a ground-state charmed hadron in association with a muon. [...] arXiv:1612.05140; LHCB-PAPER-2016-031; CERN-EP-2016-201.- Geneva : CERN, 2017 - 21 p. - Published in : Phys. Rev. Lett. 118 (2017) 052002 Fulltext: arXiv:1612.05140 - PDF; 10.1103_PhysRevLett.118.052002 - PDF; Related data file(s): ZIP;

2016-12-12
09:41
 Measurements of top-quark pair to $Z$-boson cross-section ratios at $\sqrt s = 13, 8, 7$TeV with the ATLAS detector / ATLAS Collaboration Ratios of top-quark pair to $Z$-boson cross sections measured from proton--proton collisions at the LHC centre-of-mass energies of $\sqrt s=13$TeV, 8TeV, and 7TeV are presented by the ATLAS Collaboration. Single ratios, at a given $\sqrt s$ for the two processes and at different $\sqrt s$ for each process, as well as double ratios of the two processes at different $\sqrt s$, are evaluated. [...] CERN-EP-2016-271; arXiv:1612.03636.- Geneva : CERN, 2017 - 55 p. - Published in : J. High Energy Phys. 1702 (2017) 117 Fulltext: ttbarZpaper_merged - PDF; arXiv:1612.03636 - PDF; Springer Open Access article: PDF;

2016-12-09
09:49
 Measurement of the prompt $J/\psi$ pair production cross-section in pp collisions at $\sqrt{s} = 8$ TeV with the ATLAS detector / ATLAS Collaboration The production of two prompt $J/\psi$ mesons, each with transverse momenta $p_{\mathrm{T}}>8.5$ GeV and rapidity $|y| < 2.1$, is studied using a sample of proton-proton collisions at $\sqrt{s} = 8$ TeV, corresponding to an integrated luminosity of 11.4 fb$^{-1}$ collected in 2012 with the ATLAS detector at the LHC. The differential cross-section, assuming unpolarised $J/\psi$ production, is measured as a function of the transverse momentum of the lower-$p_{\mathrm{T}}$ $J/\psi$ meson, di-$J/\psi$ $p_{\mathrm{T}}$ and mass, the difference in rapidity between the two $J/\psi$ mesons, and the azimuthal angle between the two $J/\psi$ mesons. [...] CERN-EP-2016-211; arXiv:1612.02950.- Geneva : CERN, 2017 - 53 p. - Published in : Eur. Phys. J. C 77 (2017) 76 Fulltext: arXiv:1612.02950 - PDF; BPHY-2015-02 - PDF; Springer Open Access article: PDF;

2016-12-09
07:44
 Observation of the decay $\Xi_b^- \to p K^-K^-$ / LHCb Collaboration Decays of the $\Xi_b^-$ and $\Omega_b^-$ baryons to the charmless final states $p h^{-}h^{\prime -}$, where $h^{(\prime)}$ denotes a kaon or pion, are searched for with the LHCb detector. The analysis is based on a sample of proton-proton collision data collected at centre-of-mass energies $\sqrt{s} = 7$ and $8 TeV$, corresponding to an integrated luminosity of $3 {\rm fb}^{-1}$. [...] CERN-EP-2016-294; LHCB-PAPER-2016-050; arXiv:1612.02244; LHCB-PAPER-2016-050; CERN-EP-2016-294.- Geneva : CERN, 2017 - 11 p. - Published in : Phys. Rev. Lett. 118 (2017) 071801 Fulltext: 10.1103_PhysRevLett.118.071801 - PDF; arXiv:1612.02244 - PDF; Related data file(s): TAR.GZ;

2016-12-05
09:52
 Search for heavy neutrinos or third-generation leptoquarks in final states with two hadronically decaying $\tau$ leptons and two jets in proton-proton collisions at $\sqrt{s} =$ 13 TeV / CMS Collaboration A search for new particles has been conducted using events with two high transverse momentum ($p_{\mathrm{T}}$) $\tau$ leptons that decay hadronically, at least two high-$p_{\mathrm{T}}$ jets, and missing transverse energy from the $\tau$ lepton decays. The analysis is performed using data from proton-proton collisions, collected by the CMS experiment in 2015 at $\sqrt{s} =$ 13 TeV, corresponding to an integrated luminosity of 2.1 fb$^{-1}$. [...] CMS-EXO-16-016; CERN-EP-2016-286; arXiv:1612.01190; CMS-EXO-16-016.- Geneva : CERN, 2017 - 34 p. - Published in : J. High Energy Phys. 1703 (2017) 077 Fulltext: cms-exo-16-016-arxiv - PDF; arXiv:1612.01190 - PDF; Springer Open Access article: PDF;

2016-12-02
12:44
 Search for decays of neutral beauty mesons into four muons / LHCb Collaboration A search for the non-resonant decays $B^0_s \rightarrow \mu^{+}\mu^{-}\mu^{+}\mu^{-}$ and $B^0 \rightarrow \mu^{+}\mu^{-}\mu^{+}\mu^{-}$ is presented. The measurement is performed using the full Run 1 data set collected in proton-proton collisions by the LHCb experiment at the LHC [...] LHCB-PAPER-2016-043; CERN-EP-2016-276; arXiv:1611.07704; LHCB-PAPER-2016-043; CERN-EP-2016-276.- Geneva : CERN, 2017 - 19 p. - Published in : J. High Energy Phys. 1703 (2017) 001 Fulltext: PDF; Springer Open Access article: PDF;