Download or read book Associated Production of W Charm in 13 TeV Proton Proton Collisions Measured with CMS and Determination of the Strange Quark Content of the Proton written by Svenja Karen Pflitsch and published by Springer Nature. This book was released on 2020-08-18 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The associated production of a W boson and a single charm quark (W+c) is the only process in proton-proton collisions that directly probes the strange quark content of the proton. In this thesis, W+charm production is measured in proton-proton collisions at the LHC at 13 TeV, as recorded by the Compact Muon Solenoid (CMS) experiment. The analysis focuses on the identification of W bosons in their leptonic decay to a muon and a neutrino and charm quarks are tagged via the full reconstruction of D*-Mesons. The measured cross sections of W+c production are used, in combination with other relevant CMS results and the most precise HERA DIS data, in a QCD analysis to determine the strange quark content of the proton. The resulting strange quark distribution and suppression, with respect to the other light sea quarks, are in good agreement with those obtained in neutrino scattering experiments and extend their kinematic reach.

Download or read book Measurement of Associated Production of a W Boson and a Charm Quark in Proton proton Collisions at s written by Albert M. Sirunyan and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Associated Production of AW Boson and a Charm Quark in Proton protoncollisions at s written by Sergio Sánchez Navas and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific knowledge experienced an age of explosion during the XX century, fruitful in discoveries that radically changed the perspective we had of Nature. Our current quest is, however, to continue questioning the fundamental aspects of everything that surrounds us, to test until the very end how far the great theories can go, and to pursue with the undeniable task of human restlessness to answer the question “and why is that?”. In the specific topic of this work, we will make use of the largest machine ever built to obtain information about some of the smallest elements of matter, measuring with the best precision up to date the cross section of a process that could shed some light on the mystery of fundamental asymmetry between matter and antimatter in the Universe. Our mind demands symmetry...

Download or read book Measurement of Associated W Charm Production in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements are presented of the associated production of a W boson and a charm-quark jet (W + c) in pp collisions at a center-of-mass energy of 7 TeV. The analysis is conducted with a data sample corresponding to a total integrated luminosity of 5 inverse femtobarns, collected by the CMS detector at the LHC. W boson candidates are identified by their decay into a charged lepton (muon or electron) and a neutrino. The W + c measurements are performed for charm-quark jets in the kinematic region $p_T^{jet} \gt$ 25 GeV, $

Download or read book Measurement of Associated Z Boson and Charm Quark Production in Proton proton Collisions at Square Root of S Equals to 13 TeV written by Luis Pinto Cabrera and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "This thesis presents the measurements of the differential production cross-sections of a Z boson in association with at least one charm-quark-initiated jet, where the Z boson decays leptonically into a muon-antimuon pair. Data recorded in proton-proton collisions by the ATLAS detector at the Large Hadron Collider (LHC) during the years of 2015 to 2018 is utilised, when the LHC was running at a center of mass energy of 13 TeV. The studied data corresponds to a total integrated luminosity of 139 fb^-1. The measurements are compared to simulated data produced at next-to-leading-order and normalized to theoretical predictions at next-to-next-leading order. The results show that predictions underestimate the total number of events by 50% but display a good modelling of all distribution shapes of the chosen observables in data. The discrepancy can be attributed to a problem in the normalisation but further studies need to be made to settle the issue"--

Download or read book Search for Associated Production of a Z Boson with a Single Top Quark and for TZ Flavour changing Interactions in Pp Collisions at sqrt s written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the production of a single top quark in association with a Z boson is presented, both to identify the expected standard model process and to search for flavour-changing neutral current interactions. The data sample corresponds to an integrated luminosity of 19.7 inverse-femtobarns recorded by the CMS experiment at the LHC in proton-proton collisions at $\sqrt{s}$ = 8 TeV. Final states with three leptons (electrons or muons) and at least one jet are investigated. An events yield compatible with tZq standard model production is observed, and the corresponding cross section is measured to be sigma(p p -> t Z q -> l nu b l+ l- q) = 10 +8/-7 fb with a significance of 2.4 standard deviations. No presence of flavour-changing neutral current production of tZq is observed. Exclusion limits at 95% confidence level on the branching fractions of a top quark decaying to a Z boson and an up or a charm quark are found to be B(t -> Z u) 0.022% and B(t - Z c)

Download or read book First Measurement of the Production of a W Boson in Association with a Single Charm Quark in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present the first measurement of the production cross section of a W boson with a single charm quark (c) in p{bar p} collisions at √s = 1.96 TeV, using soft muon tagging of c jets. In a data sample of ≈ 1.8 fb−1, recorded with the CDF II detector at the Fermilab Tevatron, they select events with W + 1 or 2 jets. They use the charge correlation between the W and the muon from the semileptonic decay of a charm hadron to extract the We signal. They measure [sigma]{sub Wc} (p{sub Tc} > 20 GeV/c,

Download or read book Electroweak Physics at the LHC written by Matthias U. Mozer and published by Springer. This book was released on 2016-03-24 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book discusses the recent experimental results obtained at the LHC that involve electroweak bosons. The results are placed into an appropriate theoretical and historical context. The work pays special attention to the rising subject of hadronically decaying bosons with high boosts, documenting the state-of-the-art identification techniques and highlighting typical results. The text is not limited to electroweak physics in the strict sense, but also discusses the use of electroweak vector-bosons as tool in the study of other subjects in particle physics, such as determinations of the proton structure or the search for new exotic particles. The book is particularly well suited for graduate students, starting their thesis work on topics that involve electroweak bosons, as the book provides a comprehensive description of phenomena observable at current accelerators as well as a summary of the most relevant experimental techniques.

Download or read book Towards Global Interpretation of LHC Data written by Toni Mäkelä and published by Springer Nature. This book was released on 2023-05-16 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the first global interpretation of measurements of jet and top quark production at the Large Hadron Collider, including a simultaneous extraction of the standard model parameters together with constraints on new physics, unbiased from the assumptions on the standard model parameters. As a long-standing problem, any hadron collider search for new physics depends on parton distribution functions, which cannot be predicted but are extracted experimentally. However, performing the extraction in the same kinematic region where physics beyond the standard model is expected to manifest causes the risk of absorbing the new physics effects into the parton distributions. In this book, the issue is addressed by extending the standard model by effective contributions from quark contact interactions describing new physics and extracting the parton distributions and standard model parameters simultaneously with setting limits on the contact interactions. In the process, the most precise single measurement of the strong coupling constant at the LHC is performed, to date. Furthermore, the book details the first investigation of the mass renormalization scale dependence of the top quark mass, highlighting the importance of a proper scale choice for obtaining robust predictions and improving the precision of experimental analyses. The initial chapters provide the reader with a succinct yet accessible introduction to the relevant theoretical and experimental topics. The presented investigations are at the edge of precision in the phenomenology of high-energy physics and serve to pave the road toward a global interpretation of LHC data.

Download or read book First Measurement of the Production of a W Boson in Association with a Single Charm Quark in P Anti p Collisions at S written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present the first measurement of the production cross section of a W boson with a single charm quark (c) in p{bar p} collisions at √s = 1.96 TeV, using soft muon tagging of c jets. In a data sample of ≈ 1.8 fb−1, recorded with the CDF II detector at the Fermilab Tevatron, they select events with W + 1 or 2 jets. They use the charge correlation between the W and the muon from the semileptonic decay of a charm hadron to extract the We signal. They measure?{sub Wc} (p{sub Tc}> 20 GeV/c,

Download or read book Search for Single Production of Vector like Quarks Decaying Into a B Quark and a W Boson in Proton proton Collisions at sqrt s written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is presented for a heavy vector-like quark, decaying into a b quark and a W boson, which is produced singly in association with a light flavor quark and a b quark. The analysis is performed using a data sample of proton-proton collisions at a center-of-mass energy of $\sqrt{s} = $ 13 TeV collected at the LHC in 2015. The data set used in the analysis corresponds to an integrated luminosity of 2.3 inverse-femtobarns. The search is carried out using events containing one electron or muon, at least one b-tagged jet with large transverse momentum, at least one jet in the forward region of the detector, and missing transverse momentum. No excess over the standard model prediction is observed. Upper limits are placed on the production cross section of heavy exotic quarks: a T quark with a charge of 2/3, and a Y quark with a charge of -4/3. For Y quarks with coupling of 0.5 and B(Y to bW) = 100%, the observed (expected) lower mass limits are 1.40 (1.0) TeV. This is the most stringent limit to date on the single production of the Y vector-like quark.

Download or read book Measurement of the Associated Production of a Vector Boson W Z and Top Quark Pair in the Opposite Sign Dilepton Channel with Pp Collisions at s written by and published by . This book was released on 2014 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: The heaviest known elementary particle predicted by the Standard Model (SM), the top quark, was discovered in 1995 by the CDF and D0 collaborations. The large top quark mass translates into a coupling to the Higgs boson close to unity and, therefore, it is expected that the top quark may play a special role in electroweak symmetry breaking. Among its various properties, the study of the coupling between the top quark and the Z-boson would allow to test the SM prediction, and search for any deviations caused by possible new physics signals. The first step towards the measurement of such a co...

Download or read book Measurement of Associated Production of Z Bosons with Charm Quark Jets in Ppbar Collisions at Sqrt s written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Top Quark antiquark Pair Production in Association with a W Or Z Boson in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the cross section for the production of top quark-antiquark pairs (${\mathrm {t}}\overline{{\mathrm {t}}}$) in association with a vector boson V (W or Z) in proton-proton collisions at $\sqrt{s} = 8$ $\, \text {TeV}$ is presented. The results are based on a dataset corresponding to an integrated luminosity of 19.5 fb$^{-1}$ recorded with the CMS detector at the LHC. The measurement is performed in three leptonic (e and $\mu$) channels: a same-sign dilepton analysis targeting ${\mathrm {t}}\overline{{\mathrm {t}}} \mathrm {W} $ events, and trilepton and four-lepton analyses designed for ${\mathrm {t}}\overline{{\mathrm {t}}} {\mathrm {Z}} $ events. In the same-sign dilepton channel, the ${\mathrm {t}}\overline{{\mathrm {t}}} \mathrm {W} $ cross section is measured as $\sigma _{{\mathrm {t}}\overline{{\mathrm {t}}} \mathrm {W}} = 170 ^{+90-80}\, \text {(stat)} \pm 70\, \text {(syst)} \, \text {fb} $, corresponding to a significance of 1.6 standard deviations over the background-only hypothesis. Combining the trilepton and four-lepton channels, a direct measurement of the ${\mathrm {t}}\overline{{\mathrm {t}}} {\mathrm {Z}} $ cross section, $\sigma _{{\mathrm {t}}\overline{{\mathrm {t}}} {\mathrm {Z}}} = 200 ^{+80-70}\, \text {(stat)} ^{+40-30}\, \text {(syst)} \mathrm{fb}^{-1} $, is obtained with a significance of 3.1 standard deviations. The measured cross sections are compatible with standard model predictions within their experimental uncertainties. The inclusive ${\mathrm {t}}\overline{{\mathrm {t}}} {\mathrm {V}} $ process is observed with a significance of 3.7 standard deviations from the combination of all three leptonic channels.

Download or read book Measurement of the Production Rate of the Charm Jet Recoiling Against the W Boson Using the D0 Detector at the Fermilab Tevatron Collider written by and published by . This book was released on 2008 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes a measurement of the rate of associated production of the W boson with the charm jet in the proton and anti-proton collisions at the center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider. The measurement has direct sensitivity to the strange quark content inside the proton. A direct measurement of the momentum distribution of the strange quark inside the proton is essential for a reliable calculation of new physics signal as well as the background processes at the collider experiments. The identification of events containing a W boson and a charm jet is based on the leptonic decays of the W boson together with a tagging technique for the charm jet identification based on the semileptonic decay of the charm quark into the muon. The charm jet recoiling against the W boson must have a minimum transverse momentum of 20 GeV and an absolute value of pseudorapidity less than 2.5. This measurement utilizes the data collected by the D0 detector at the Fermilab Collider. The measured rate of the charm jet production in association with the W boson in the inclusive jet production with the W boson is 0.074 ± 0.023, which is in agreement with the theoretical predictions at the leading order in Quantum Chromodynamics.

Download or read book Observation of the Associated Production of a Single Top Quark and a W Boson in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for New Heavy Charged Bosons and Measurement of High Mass Drell Yan Production in Proton Proton Collisions written by Markus Zinser and published by Springer. This book was released on 2018-09-25 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents two analyses, the first of which involves the search for a new heavy charged gauge boson, a so-called W' boson. This new gauge boson is predicted by some theories extending the Standard Model gauge group to solve some of its conceptual problems. Decays of the W' boson in final states with a lepton (l± = e± , μ±) and the corresponding (anti-)neutrino are considered. Data collected by the ATLAS experiment in 2015 at a center of mass energy of √s =13 TeV is used for the analysis. In turn, the second analysis presents a measurement of the double-differential cross section of the process pp->Z/gamma^* + X -> l^+l^- + X, including a gamma gamma induced contribution, at a center of mass energy of sqrt{s} = 8 TeV. The measurement is performed in an invariant mass region of 116 GeV to 1500 GeV as a function of invariant mass and absolute rapidity of the l^+l^-- pair, and as a function of invariant mass and pseudorapidity separation of the l^+l^-- pair. The data analyzed was recorded by the ATLAS experiment in 2012 and corresponds to an integrated luminosity of 20.3/fb. It is expected that the measured cross sections are sensitive to the PDFs at very high values of the Bjorken-x scaling variable, and to the photon structure of the proton.