scholarly journals Electroweak measurements from W, Z and photon final states

2014 ◽  
Vol 31 ◽  
pp. 1460276
Author(s):  
Hang Yin ◽  
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Z Boson ◽  
W Boson ◽  
Charge Asymmetry ◽  
Distribution Functions ◽  
Boson Mass ◽  
Electroweak Theory ◽  
Final States ◽  
Parton Distribution Functions

We present the most recent precision electroweak measurements of single W and Z boson cross section and properties from the LHC and Tevatron colliders, analyzing data collected by ATLAS, CDF, CMS, D0, and LHCb detectors. The results include the measurement of the single W and Z boson cross section at LHC, the differential cross section measurements, the measurement of W boson mass, the measurement of W and Z charge asymmetry. These measurements provide precision tests on the electroweak theory, high order predictions and the information can be used to constraint parton distribution functions.

scholarly journals Determination of αs in NNLO QCD using H1 jet cross section measurements

2019 ◽  
Vol 206 ◽  
pp. 01002
Author(s):  
Vladimir Chekelian
Keyword(s):  
Strong Coupling ◽  
Cross Section ◽  
Cross Sections ◽  
Neutral Current ◽  
Distribution Functions ◽  
Boson Mass ◽  
Parton Distribution Functions ◽  
Inclusive Jet ◽  
Using Data ◽  
Jet Cross Sections

Measurements of jet cross sections in neutral current deep-inelastic scattering (NC DIS) using data taken with the H1 detector at HERA are accomplished by the precision measurement of double-differential inclusive jet, dijet and trijet cross sections at low photon virtualities 5.5 < Q2 < 80 GeV2, and by extending previous inclusive jet measurements in the range 150 < Q2 < 15000 GeV2 to low transverse jet momenta 5 < PT < 7 GeV. The strong coupling constant at the Z-boson mass, αs(mZ), is determined in next-to-next-to-leading order (NNLO) QCD using H1 inclusive jet and dijet cross section measurements. Complementary, αs(mZ) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with the QCD expectations.

AN ELECTROWEAK FACTORIZATION THEOREM

1989 ◽  
Vol 04 (12) ◽  
pp. 2977-2994
Author(s):  
S. LAKSHMIBALA ◽  
G. RAJASEKARAN
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Z Boson ◽  
Single Photon ◽  
Tree Level ◽  
Electroweak Theory ◽  
Factorization Property ◽  
Photon Exchange ◽  
Boson Exchange ◽  
Linearly Polarized

We prove a factorization property relating the photon exchange, the Z boson exchange and the electroweak interference terms of the differential cross-section for the process fermion+ antifermion→bosons occurring through the exchange of a single photon and a single Z boson. The property holds at tree-level when the bosons are unpolarized or linearly polarized and the fermions are unpolarized or longitudinally polarized. We have illustrated the factorization property with examples in the standard electroweak theory as well as its extensions and modifications.

scholarly journals Measurement of the cross-section and charge asymmetry of W bosons produced in proton–proton collisions at $$\sqrt{s}=8~\text {TeV}$$ with the ATLAS detector

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
O. Abdinov ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Charge Asymmetry ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Proton Proton ◽  
Proton Collisions ◽  
The Cross ◽  
Proton Proton Collisions ◽  
Integrated Luminosity

Abstract This paper presents measurements of the $$W^+ \rightarrow \mu ^+\nu $$W+→μ+ν and $$W^- \rightarrow \mu ^-\nu $$W-→μ-ν cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton–proton collisions at a centre-of-mass energy of 8 $$\text {TeV}$$TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of $$20.2~\text{ fb }^{-1}$$20.2fb-1. The precision of the cross-section measurements varies between 0.8 and 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.

scholarly journals Determination of the transverse momentum of W bosons in hadronic collisions via forward folding techniques

2016 ◽  
Vol 31 (14) ◽  
pp. 1650069
Author(s):  
Jakub Cuth ◽  
Kyrylo Merkotan ◽  
Matthias Schott ◽  
Samuel Webb
Keyword(s):  
Transverse Momentum ◽  
Z Boson ◽  
W Boson ◽  
W Bosons ◽  
Boson Mass ◽  
Final States ◽  
Transverse Momentum Spectrum ◽  
Systematic Uncertainties ◽  
Hadronic Collisions

The measurement of the transverse momentum of W bosons in hadron collisions provides not only an important test of quantum chromodynamic (QCD) calculations, but also is a crucial input for the precision measurement of the W boson mass. While the measurement of the Z boson transverse momentum is experimentally well under control, the available unfolding techniques for the W boson final states lead generically to relatively large uncertainties. In this paper, we present a new methodology to estimate the W boson transverse momentum spectrum, significantly improving the systematic uncertainties of current approaches.

scholarly journals Z-boson production in p-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ = 8.16 TeV and Pb-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ = 5.02 TeV

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
S. Acharya ◽  
◽  
D. Adamová ◽  
A. Adler ◽  
J. Adolfsson ◽  
...  
Keyword(s):  
Z Boson ◽  
Decay Channel ◽  
Theoretical Calculations ◽  
Center Of Mass ◽  
Laboratory Frame ◽  
Distribution Functions ◽  
Boson Production ◽  
Free Nucleon ◽  
Parton Distribution Functions ◽  
Nuclear Modifications

Abstract Measurement of Z-boson production in p-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ s NN = 8.16 TeV and Pb-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ s NN = 5.02 TeV is reported. It is performed in the dimuon decay channel, through the detection of muons with pseudorapidity −4 < ημ< −2.5 and transverse momentum $$ {p}_{\mathrm{T}}^{\mu } $$ p T μ > 20 GeV/c in the laboratory frame. The invariant yield and nuclear modification factor are measured for opposite-sign dimuons with invariant mass 60 < mμμ< 120 GeV/c2 and rapidity 2.5 <$$ {y}_{\mathrm{cms}}^{\mu \mu} $$ y cms μμ < 4. They are presented as a function of rapidity and, for the Pb-Pb collisions, of centrality as well. The results are compared with theoretical calculations, both with and without nuclear modifications to the Parton Distribution Functions (PDFs). In p-Pb collisions the center-of-mass frame is boosted with respect to the laboratory frame, and the measurements cover the backward (−4.46 <$$ {y}_{\mathrm{cms}}^{\mu \mu} $$ y cms μμ < −2.96) and forward (2.03 <$$ {y}_{\mathrm{cms}}^{\mu \mu} $$ y cms μμ < 3.53) rapidity regions. For the p-Pb collisions, the results are consistent within experimental and theoretical uncertainties with calculations that include both free-nucleon and nuclear-modified PDFs. For the Pb-Pb collisions, a 3.4σ deviation is seen in the integrated yield between the data and calculations based on the free-nucleon PDFs, while good agreement is found once nuclear modifications are considered.

scholarly journals HIGGS PRODUCTION IN ASSOCIATION WITH BOTTOM QUARKS AT HADRON COLLIDERS

2006 ◽  
Vol 21 (02) ◽  
pp. 89-109 ◽  
Author(s):  
S. DAWSON ◽  
C. B. JACKSON ◽  
L. REINA ◽  
D. WACKEROTH
Keyword(s):  
Standard Model ◽  
Cross Sections ◽  
Hadron Collider ◽  
Distribution Functions ◽  
Bottom Quarks ◽  
Final States ◽  
Leading Order ◽  
Hadron Colliders ◽  
Parton Distribution Functions ◽  
Model Case

We review the present status of the QCD corrected cross-sections and kinematic distributions for the production of a Higgs boson in association with bottom quarks at the Fermilab Tevatron and CERN Large Hadron Collider. Results are presented for the Minimal Supersymmetric Standard Model where, for large tan β, these production modes can be greatly enhanced compared to the Standard Model case. The next-to-leading order QCD results are much less sensitive to the renormalization and factorization scales than the lowest order results, but have a significant dependence on the choice of the renormalization scheme for the bottom quark Yukawa coupling. We also investigate the uncertainties coming from the Parton Distribution Functions and find that these uncertainties can be comparable to the uncertainties from the remaining scale dependence of the next-to-leading order results. We present results separately for the different final states depending on the number of bottom quarks identified.

INELASTIC PHOTOPRODUCTION OF W-BOSON

1998 ◽  
Vol 13 (25) ◽  
pp. 2013-2020
Author(s):  
S. M. KHAIRUL ALAM ◽  
A. M. HARUN AR RASHID
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
W Boson ◽  
Electric Quadrupole ◽  
Parton Model ◽  
High Energy ◽  
Electric Quadrupole Moment ◽  
Photoproduction Process ◽  
Quark Parton Model ◽  
High Energy Collider

We study the WWγ vertex through the process γq→Wq′ where q denotes the quark at a future high energy collider. The differential cross-section for the photoproduction process γq→Wq′ is computed with both anomalous magnetic moment κ and electric quadrupole moment λ for the W-boson. The deep inelastic photoproduction of W± is also calculated in a quark-parton model.

Accurate prediction of the Drell-Yan φ∗ η distribution in wide dilepton mass and rapidity ranges in pp collisions through NNLO+N3LL

2021 ◽  
Author(s):  
Kadir Ocalan
Keyword(s):  
Cross Sections ◽  
Good Description ◽  
Neutral Current ◽  
Mass Range ◽  
Theoretical Description ◽  
Distribution Functions ◽  
Boson Mass ◽  
Pp Collisions ◽  
Parton Distribution Functions ◽  
Central Detector

Abstract This paper presents high-accuracy predictions for the differential cross sections as a function of the key observable φ*η of the neutral-current Drell-Yan (DY) dilepton production in proton-proton (pp) collisions. The differential distributions for the φ*η are presented by using the state-of-the-art predictions from the combined calculations of fixed-order perturbative QCD corrections at next-to-next-to-leading order (NNLO) accuracy and resummation of large logarithmic terms at next-to-next-to-leading logarithmic (NNLL) and next-to-NNLL (N3LL) accuracies, i.e., NNLO+NNLL and NNLO+N3LL, respectively. The predicted distributions are reported for a thorough set of the DY dilepton invariant mass mll ranges, spanning a wide kinematic region of 50 < mll< 1000 GeV both near and away from the Z-boson mass peak, and rapidity yll ranges in the central detector acceptance region of |yll| < 2.4. The differential φ*η distributions in the wide mll and yll ranges offer stringent tests to assess the reliability of the predictions, where the mll and yll are closely correlated with the parton distribution functions (PDFs) of the incoming partons. The merged predictions through NNLO+N3LL are observed to provide good description of the 13 TeV pp collision data for the φ*η (including the dilepton transverse momentum pll T as well) distributions in almost the entire mll and yll ranges, apart from the intermediate- to high-φ*η region in the lowest mass range 50–76 GeV which is assessed to constitute a challenge for the presented predictions. The merged predictions at NNLO+N3LL are also reported at 14 TeV for the upcoming high-luminosity running era of the LHC, in which increasing amount of data is expected to require more accurate and precise theoretical description. The most recent PDF models MSHT20 and CT18 are tested for the first time in addition to the NNPDF3.1 exploiting the merged φ*η predictions.

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