# PH-EP Articles

Senast inlagda poster:
2015-09-03
07:55
 Measurement of forward $J/\psi$ production cross-sections in $pp$ collisions at $\sqrt{s}=13$ TeV / LHCb collaboration The production of $J/\psi$ mesons in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=13$ TeV is studied with the LHCb detector. Cross-section measurements are performed as a function of the transverse momentum $p_\mathrm{T}$ and the rapidity $y$ of the $J/\psi$ meson in the region $p_\mathrm{T}<14 \mathrm{GeV}/c$ and $2.0 < y < 4.5$, for both prompt $J/\psi$ mesons and $J/\psi$ mesons from $b$-hadron decays. [...] arXiv:1509.00771; LHCB-PAPER-2015-037; CERN-PH-EP-2015-222.- Geneva : CERN, 2015 - 33 p. - Published in : J. High Energy Phys. 10 (2015) 172 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint

2015-09-02
08:54
 First measurement of the differential branching fraction and $C\!P$ asymmetry of the $B^\pm\to\pi^\pm\mu^+\mu^-$ decay / LHCb collaboration The differential branching fraction with respect to the dimuon invariant mass squared, and the $C\!P$ asymmetry of the $B^\pm\to\pi^\pm\mu^+\mu^-$ decay are measured for the first time. The CKM matrix elements $|V_{td}|$ and $|V_{ts}|$, and the ratio $|V_{td}/V_{ts}|$ are determined. [...] arXiv:1509.00414; LHCB-PAPER-2015-035; CERN-PH-EP-2015-219.- Geneva : CERN, 2015 - 22 p. - Published in : J. High Energy Phys. 10 (2015) 034 Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2015-09-02
08:53
 Measurement of ${C\!P}$ violation parameters and polarisation fractions in ${B_s^0\to J/\psi \overline{K}^{*0}}$ decays / LHCb collaboration The first measurement of ${C\!P}$ asymmetries in the decay ${B_s^0\to J/\psi \overline{K}^{*}(892)^{0}}$ and an updated measurement of its branching fraction and polarisation fractions are presented. The results are obtained using data corresponding to an integrated luminosity of $3.0\,fb^{-1}$ of proton-proton collisions recorded with the LHCb detector at centre-of-mass energies of $7$ and $8\,\mathrm{TeV}$. [...] arXiv:1509.00400; CERN-PH-EP-2015-224; LHCB-PAPER-2015-034.- Geneva : CERN, 2015 - 39 p. - Published in : J. High Energy Phys. 11 (2015) 082 Fulltext: PDF; Related data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint

2015-08-27
07:54
 Measurement of the time-integrated $CP$ asymmetry in $D^0 \to K^0_S K^0_S$ decays / LHCb collaboration The time-integrated $CP$ asymmetry in the decay $D^0 \to K^0_S K^0_S$ is measured using $3 fb^{-1}$ of proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The flavour of the $D^0$ meson is determined by use of the decay $D^{*+} \to D^0 \pi^+$ and its charge conjugate mode. [...] arXiv:1508.06087; CERN-PH-EP-2015-215; LHCB-PAPER-2015-030.- Geneva : CERN, 2015 - 16 p. - Published in : J. High Energy Phys. 10 (2015) 055 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint

2015-08-26
17:44
 Summary of the ATLAS experiment's sensitivity to supersymmetry after LHC Run 1 - interpreted in the phenomenological MSSM / ATLAS Collaboration A summary of the constraints from the ATLAS experiment on $R$-parity conserving supersymmetry is presented. Results from 22 separate ATLAS searches are considered, each based on analysis of up to 20.3 fb$^{-1}$ of proton-proton collision data at the centre-of-mass energy of $\sqrt{s}$ = 7 and 8 TeV at the Large Hadron Collider.  The results are interpreted in the context of the 19-parameter phenomenological minimal supersymmetric standard model, in which the lightest supersymmetric particle is a neutralino, taking into account constraints from previous precision electroweak and flavour measurements as well as from dark matter related measurements.  The results are presented in terms of constraints on supersymmetric particle masses and are compared to limits from simplified models. [...] arXiv:1508.06608; CERN-PH-EP-2015-214.- Geneva : CERN, 2015 - 58 p. - Published in : J. High Energy Phys. 10 (2015) 134 Fulltext: PDF; External links: Previous draft version; Preprint

2015-08-18
07:49
 Search for hidden-sector bosons in $B^0 \!\to K^{*0}\mu^+\mu^-$ decays / LHCb collaboration A search is presented for hidden-sector bosons, $\chi$, produced in the decay ${B^0\!\to K^*(892)^0\chi}$, with $K^*(892)^0\!\to K^{+}\pi^{-}$ and $\chi\!\to\mu^+\mu^-$. The search is performed using $pp$-collision data corresponding to 3.0 fb$^{-1}$ collected with the LHCb detector. [...] arXiv:1508.04094; CERN-PH-EP-2015-202; LHCB-PAPER-2015-036.- Geneva : CERN, 2015 - 21 p. - Published in : Phys. Rev. Lett. 115 (2015) 161802 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; External link: Preprint

2015-08-06
05:14
 Measurement of transverse energy-energy correlations in multi-jet events in $pp$ collisions at $\sqrt{s} = 7$ TeV using the ATLAS detector and determination of the strong coupling constant $\alpha_{\mathrm{s}}(m_Z)$ / ATLAS Collaboration High transverse momentum jets produced in pp collisions at a centre of mass energy of 7 TeV are used to measure the transverse energy--energy correlation function and its associated azimuthal asymmetry. The data were recorded with the ATLAS detector at the LHC in the year 2011 and correspond to an integrated luminosity of 158 $\mathrm{pb}^{-1}$. [...] arXiv:1508.01579; CERN-PH-EP-2015-177.- Geneva : CERN, 2015 - 19 p. - Published in : Phys. Lett. B 750 (2015) 427-447 Elsevier Open Access article: PDF; Fulltext: PDF; External links: Previous draft version; Preprint

2015-08-05
08:25
 Measurement of the $B_s^0 \to \phi \phi$ branching fraction and search for the decay $B^0 \to \phi \phi$ / LHCb collaboration Using a dataset corresponding to an integrated luminosity of 3.0 fb$^{-1}$ collected in $pp$ collisions at centre-of-mass energies of 7 and 8 TeV, the $B_s^0 \to \phi \phi$ branching fraction is measured to be $\mathcal{B}(B_s^0 \to \phi \phi) = ( 1.84 \pm 0.05 (\text{stat}) \pm 0.07 (\text{syst}) \pm 0.11 (f_s/f_d) \pm 0.12 (\text{norm}) ) \times 10^{-5},$ where $f_s/f_d$ represents the ratio of the $B_s^0$ to $B^0$ production cross-sections, and the $B^0 \to \phi K^*(892)^0$ decay mode is used for normalization. This is the most precise measurement of this branching fraction to date, representing a factor five reduction in the statistical uncertainty compared with the previous best measurement. [...] arXiv:1508.00788; LHCB-PAPER-2015-028; CERN-PH-EP-2015-198.- Geneva : CERN, 2015 - 20 p. - Published in : J. High Energy Phys. 10 (2015) 053 Fulltext: PDF; Related data file(s): ZIP; External link: Preprint

2015-07-30
07:53
 $B$ flavour tagging using charm decays at the LHCb experiment / LHCb collaboration An algorithm is described for tagging the flavour content at production of neutral $B$ mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a $B$ meson with the charge of a reconstructed secondary charm hadron from the decay of the other $b$ hadron produced in the proton-proton collision. [...] arXiv:1507.07892; CERN-PH-EP-2015-193; LHCB-PAPER-2015-027.- Geneva : CERN, 2015 - 19 p. - Published in : J. Instrum. 10 (2015) P10005 Fulltext: PDF; Related data file(s): ZIP; Related supplementary data file(s): ZIP; External link: Preprint

2015-07-29
16:44
 Measurement of the branching ratio $\Gamma(\Lambda_b^0 \rightarrow \psi(2S)\Lambda^0)/\Gamma(\Lambda_b^0 \rightarrow J/\psi\Lambda^0)$ with the ATLAS detector / ATLAS Collaboration An observation of the $\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0$ decay and a comparison of its branching fraction with that of the $\Lambda_b^0 \rightarrow J/\psi \Lambda^0$ decay has been made with the ATLAS detector in proton--proton collisions at $\sqrt{s}=8\,$TeV at the LHC using an integrated luminosity of $20.6\,$fb$^{-1}$. The $J/\psi$ and $\psi(2S)$ mesons are reconstructed in their decays to a muon pair, while the $\Lambda^0\rightarrow p\pi^-$ decay is exploited for the $\Lambda^0$ baryon reconstruction. [...] arXiv:1507.08202; CERN-PH-EP-2015-164.- Geneva : CERN, 2015 - 12 p. - Published in : Phys. Lett. B 751 (2015) 63-80 Fulltext: PDF; External links: Previous draft version; Preprint