Physics Commons^™

Search For Standard Model Production Of Four Top Quarks In The Lepton + Jets Channel In Pp Collisions At S√=8 Tev, The Cms Collaboration, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

A search is presented for standard model (SM) production of four top quarks (t¯tt¯t) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6 fb−1 recorded at a centre-of-mass energy of 8TeV with the CMS detector at the CERN LHC. The expected cross section for SM t¯tt¯t production is SM t¯tt¯t 1 fb. A combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal and large background. The data are consistent with expectations of the SM, and an upper limit of 32 fb is set at a …

Rratum: Search For The Associated Production Of The Higgs Boson With A Top-Quark Pair, The Cms Collaboration, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

Erratum:

The x-axis of figure 2, lower left panel (“Lepton + >- 6 jets + 2 b-tags”) should be replaced with “3rd highest CSV output”.

Measurement Of Prompt J/Ψ Pair Production In Pp Collisions At S√ = 7 Tev, The Cms Collaboration, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

Production of prompt J/ψ meson pairs in proton-proton collisions at s" role="presentation" style="box-sizing: inherit; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; text-wrap: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">s√� = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb⁻¹. The two J/ψ mesons are fully reconstructed via their decays into μ ⁺ μ ⁻ pairs. This observation provides for the first time access to the …

Modulation Of Galactic Cosmic Rays During The Unusual Solar Minimum Between Cycles 23 And 24, L.-L. Zhao, G. Qin, Ming Zhang, B. Heber

Aerospace, Physics, and Space Science Faculty Publications

During the recent solar minimum between cycles 23 and 24 (solar minimum P23∕24), the intensity of galactic cosmic rays (GCR) measured at the Earth was the highest ever recorded since space age. It is the purpose of this paper to resolve the most plausible mechanism for this unusually high intensity. A GCR transport model in three-dimensional heliosphere based on a simulation of Markov stochastic process is used to find the relation of cosmic ray modulation to various transport parameters, including solar wind (SW) speed, distance of heliospheric boundary, magnitude of interplanetary magnetic field (IMF) at the Earth, tilt angle of …

Search For Pair Production Of Excited Top Quarks In The Lepton + Jets Final State, The Cms Collaboration, S. Chatrchyan, V. Khachatryan, Marc M. Baarmand, B. Dorney, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

A search is performed for pair-produced spin-3/2 excited top quarks (t∗t¯∗)" role="presentation" style="box-sizing: inherit; display: inline-block; line-height: normal; font-size: 16.7111px; word-spacing: normal; overflow-wrap: normal; text-wrap: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">(t∗t¯∗), each decaying to a top quark and a gluon. The search uses data collected with the CMS detector from pp collisions at a center-of-mass energy of s" role="presentation" style="box-sizing: inherit; display: inline-block; line-height: normal; font-size: 16.7111px; word-spacing: normal; overflow-wrap: normal; text-wrap: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: …

Measurements Of The Tt- Charge Asymmetry Using The Dilepton Decay Channel In Pp Collisions At Square Root S = 7 Tev, The Cms Collaboration, S. Chatrchyan, V. Khachatryan, Marc M. Baarmand, B. Dorney, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

The t¯t charge asymmetry in proton-proton collisions at p s = 7TeV is measured using the dilepton decay channel (ee, eμ, or μμ). The data correspond to a total integrated luminosity of 5.0 fb−1, collected by the CMS experiment at the LHC. The t¯t and lepton charge asymmetries, defined as the differences in absolute values of the rapidities between the reconstructed top quarks and antiquarks and of the pseudorapidities between the positive and negative leptons, respectively, are measured to be AC = −0.010 ± 0.017 (stat.) ± 0.008 (syst.) and Alep C = 0.009 ± 0.010 (stat.) ± 0.006 (syst.). …