scholarly journals Production and electromagnetic decay of hyperons: a feasibility study with HADES as a phase-0 experiment at FAIR

2021 ◽  
Vol 57 (4) ◽  
Author(s):  
J. Adamczewski-Musch ◽  
◽  
A. Belyaev ◽  
A. Blanco ◽  
C. Blume ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Feasibility Study ◽  
Cross Sections ◽  
Production Cross ◽  
Electromagnetic Decay ◽  
Electromagnetic Decays ◽  
Detector Acceptance ◽  
Phase 0 ◽  
Forward Detector ◽  
Expected Signal

AbstractA feasibility study has been performed in order to investigate the performance of the HADES  detector to measure the electromagnetic decays of the hyperon resonances $$\Sigma (1385)^{0}$$ Σ ( 1385 ) 0 ,  $$\Lambda (1405)$$ Λ ( 1405 )   and $$\Lambda (1520)$$ Λ ( 1520 )   as well as the production of double strange baryon systems $$\Xi ^{-}$$ Ξ -  and $$\Lambda $$ Λ $$\Lambda $$ Λ  in p + p reactions at a beam kinetic energy of $$4.5\,{\mathrm{GeV}}$$ 4.5 GeV . The existing HADES  detector will be upgraded by a new Forward Detector, which extends the detector acceptance into a range of polar angles that plays a crucial role for these investigations. The analysis of each channel is preceded by a consideration of the production cross-sections. Afterwards the expected signal count rates using a target consisting of either liquid hydrogen or polyethylene are summarized.

Spallation of 32S ions at ultra-relativistic energies in nuclear emulsion

2004 ◽  
Vol 82 (4) ◽  
pp. 263-275 ◽  
Author(s):  
M El-Nadi ◽  
A Abdelsalam ◽  
E A Shaat ◽  
N Ali Mossa ◽  
Z Abou Moussa ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Energy Dependence ◽  
Cross Sections ◽  
Nuclear Emulsion ◽  
Rest Frame ◽  
Production Cross ◽  
Combined Model ◽  
200 Gev ◽  
Nuclear Events ◽  
Good Agreement

Partial production cross sections of electromagnetic breakup of 32S projectiles at two widely differing energies were measured using an emulsion target. The electromagnetic dissociation represents about 6% and 17% of the total number of nuclear events at Elab/A = 3.7 and 200 GeV, respectively. The experimental electromagnetic cross sections σexpEMD show an energy dependence that is well reproduced by the Weizsacker–Williams approximation. The value of σexpEMD at 200A GeV (with γ >> 1) shows a good agreement with that predicted by the combined model of Pshenichnov et al. Examination of the reactions (γ, p) and (γ, He) reveals that the ratio of 1 p/1 He cross sections is close to unity at Dubna energy (3.7A GeV), while it rapidly increases to 3.0 ± 0.6 at CERN energy (200A GeV). In most of the observed dissociation modes, the total kinetic energy of the fragments in the projectile rest frame is lower than 50 MeV. Nevertheless, it is possible that the contribution of excitation modes of the different multipolarities is determining in this region. PACS No.: 25.70

scholarly journals Study of excited $$\varvec{\varXi }$$ baryons with the $$\overline{\text{ P }}$$ANDA detector

2021 ◽  
Vol 57 (4) ◽  
Author(s):  
G. Barucca ◽  
F. Davì ◽  
G. Lancioni ◽  
P. Mengucci ◽  
L. Montalto ◽  
...  
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Direct Access ◽  
Final States ◽  
Excitation Spectra ◽  
Decay Modes ◽  
Baryon Spectrum ◽  
Detector Acceptance ◽  
Independent Information ◽  
Insight Into

AbstractThe study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards $$N^*$$ N ∗ and $$\varDelta $$ Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the $$N^*$$ N ∗ and $$\varDelta $$ Δ spectra. The future antiproton experiment $$\overline{\text{ P }}$$ P ¯ ANDA will provide direct access to final states containing a $${\overline{\varXi }}\varXi $$ Ξ ¯ Ξ pair, for which production cross sections up to $$\mu \text{ b }$$ μ b are expected in $$\bar{\text{ p }}$$ p ¯ p reactions. With a luminosity of $$L=10^{31}$$ L = 10 31 cm$$^{-2}$$ - 2 s$$^{-1}$$ - 1 in the first phase of the experiment, the expected cross sections correspond to a production rate of $$\sim 10^6\, \text{ events }/\text{day }$$ ∼ 10 6 events / day . With a nearly $$4\pi $$ 4 π detector acceptance, $$\overline{\text{ P }}$$ P ¯ ANDA will thus be a hyperon factory. In this study, reactions of the type $$\bar{\text{ p }}$$ p ¯ p $$\rightarrow $$ → $${\overline{\varXi }}^{+}$$ Ξ ¯ + $$\varXi ^{*-}$$ Ξ ∗ - as well as $$\bar{\text{ p }}$$ p ¯ p $$\rightarrow $$ → $${\overline{\varXi }}^{*+}$$ Ξ ¯ ∗ + $$\varXi ^{-}$$ Ξ - with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking.

scholarly journals Measurement of $$W^{\pm }$$-boson and Z-boson production cross-sections in pp collisions at $$\sqrt{s}=2.76$$ TeV with the ATLAS detector

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
O. Abdinov ◽  
...  
Keyword(s):  
Cross Sections ◽  
Z Boson ◽  
Production Cross ◽  
Centre Of Mass ◽  
Mass Energy ◽  
Decay Channels ◽  
Atlas Data ◽  
Full Phase Space ◽  
Systematic Uncertainties ◽  
Detector Acceptance

Abstract The production cross-sections for $$W^{\pm }$$W± and Z bosons are measured using ATLAS data corresponding to an integrated luminosity of 4.0 pb$$^{-1}$$-1 collected at a centre-of-mass energy $$\sqrt{s}=2.76$$s=2.76 TeV. The decay channels $$W \rightarrow \ell \nu $$W→ℓν and $$Z \rightarrow \ell \ell $$Z→ℓℓ are used, where $$\ell $$ℓ can be an electron or a muon. The cross-sections are presented for a fiducial region defined by the detector acceptance and are also extrapolated to the full phase space for the total inclusive production cross-section. The combined (average) total inclusive cross-sections for the electron and muon channels are: $$\begin{aligned} \sigma ^{\text {tot}}_{W^{+}\rightarrow \ell \nu }= & {} 2312 \pm 26\ (\text {stat.})\\&\pm 27\ (\text {syst.}) \pm 72\ (\text {lumi.}) \pm 30\ (\text {extr.})~\text {pb} , \\ \sigma ^{\text {tot}}_{W^{-}\rightarrow \ell \nu }= & {} 1399 \pm 21\ (\text {stat.})\ \pm 17\ (\text {syst.}) \\&\pm 43\ (\text {lumi.}) \pm 21\ (\text {extr.})~\text {pb} , \\ \sigma ^{\text {tot}}_{Z \rightarrow \ell \ell }= & {} 323.4 \pm 9.8\ (\text {stat.}) \pm 5.0\ (\text {syst.})\\&\pm 10.0\ (\text {lumi.}) \pm 5.5 (\text {extr.}) ~\text {pb} . \end{aligned}$$σW+→ℓνtot=2312±26(stat.)±27(syst.)±72(lumi.)±30(extr.)pb,σW-→ℓνtot=1399±21(stat.)±17(syst.)±43(lumi.)±21(extr.)pb,σZ→ℓℓtot=323.4±9.8(stat.)±5.0(syst.)±10.0(lumi.)±5.5(extr.)pb.Measured ratios and asymmetries constructed using these cross-sections are also presented. These observables benefit from full or partial cancellation of many systematic uncertainties that are correlated between the different measurements.

scholarly journals ω AND η MESON PRODUCTION IN p+p REACTIONS AT Ekin = 3.5 GeV

2011 ◽  
Vol 26 (03n04) ◽  
pp. 694-696 ◽  
Author(s):  
◽  
KHALED TEILAB
Keyword(s):  
Angular Distribution ◽  
Kinetic Energy ◽  
Cross Sections ◽  
Energy Production ◽  
Production Cross ◽  
Meson Production ◽  
Angular Distributions ◽  
Exclusive Production ◽  
Relative Contribution ◽  
Dalitz Plots

We report on the exclusive production of ω and η mesons in p + p reactions at 3.5 GeV beam kinetic energy. Production cross sections, angular distributions and Dalitz plots of both mesons were determined. Moreover, the relative contribution of the N(1535) resonance in η production at this energy was evaluated. We conclude that η mesons produced via N(1535) exihibit an isotropic angular distribution, whereas those produced directly show a strong anisotropic distribition. ω mesons show a slightly anisotropic angular distribition.

scholarly journals Collinear expansion for color singlet cross sections

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Markus A. Ebert ◽  
Bernhard Mistlberger ◽  
Gherardo Vita
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Production Cross ◽  
Gluon Fusion ◽  
Building Blocks ◽  
Color Singlet ◽  
Final State ◽  
Beam Function ◽  
Kinematic Limit ◽  
State Radiation

Abstract We demonstrate how to efficiently expand cross sections for color-singlet production at hadron colliders around the kinematic limit of all final state radiation being collinear to one of the incoming hadrons. This expansion is systematically improvable and applicable to a large class of physical observables. We demonstrate the viability of this technique by obtaining the first two terms in the collinear expansion of the rapidity distribution of the gluon fusion Higgs boson production cross section at next-to-next-to leading order (NNLO) in QCD perturbation theory. Furthermore, we illustrate how this technique is used to extract universal building blocks of scattering cross section like the N-jettiness and transverse momentum beam function at NNLO.

scholarly journals Heavy-flavor hadro-production with heavy-quark masses renormalized in the $$ \overline{\mathrm{MS}} $$, MSR and on-shell schemes

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
M. V. Garzelli ◽  
L. Kemmler ◽  
S. Moch ◽  
O. Zenaiev
Keyword(s):  
Heavy Quark ◽  
Cross Sections ◽  
Top Quark ◽  
Quark Mass ◽  
Production Cross ◽  
Hadron Collider ◽  
Distribution Functions ◽  
Heavy Flavor ◽  
Parton Distribution Functions ◽  
Heavy Quark Mass

Abstract We present predictions for heavy-quark production at the Large Hadron Collider making use of the $$ \overline{\mathrm{MS}} $$ MS ¯ and MSR renormalization schemes for the heavy-quark mass as alternatives to the widely used on-shell renormalization scheme. We compute single and double differential distributions including QCD corrections at next-to-leading order and investigate the renormalization and factorization scale dependence as well as the perturbative convergence in these mass renormalization schemes. The implementation is based on publicly available programs, MCFM and xFitter, extending their capabilities. Our results are applied to extract the top-quark mass using measurements of the total and differential $$ t\overline{t} $$ t t ¯ production cross-sections and to investigate constraints on parton distribution functions, especially on the gluon distribution at low x values, from available LHC data on heavy-flavor hadro-production.

scholarly journals Charged current Drell-Yan production at N3LO

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Claude Duhr ◽  
Falko Dulat ◽  
Bernhard Mistlberger
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Production Cross Section ◽  
Production Cross ◽  
Hadron Collider ◽  
Charge Asymmetry ◽  
Charged Current ◽  
Leading Order ◽  
Neutrino Pair ◽  
The Impact

Abstract We present the production cross section for a lepton-neutrino pair at the Large Hadron Collider computed at next-to-next-to-next-to-leading order (N3LO) in QCD perturbation theory. We compute the partonic coefficient functions of a virtual W± boson at this order. We then use these analytic functions to study the progression of the perturbative series in different observables. In particular, we investigate the impact of the newly obtained corrections on the inclusive production cross section of W± bosons, as well as on the ratios of the production cross sections for W+, W− and/or a virtual photon. Finally, we present N3LO predictions for the charge asymmetry at the LHC.

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