scholarly journals STUDY OF THE PRODUCTION MECHANISM OF THE η MESON BY MEANS OF ANALYSING POWER MEASUREMENTS

2007 ◽  
Vol 22 (02n03) ◽  
pp. 518-522
Author(s):  
◽  
R. Czyżykiewicz ◽  
P. Moskal ◽  
H.-H. Adam ◽  
A. Budzanowski ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Meson Exchange ◽  
Production Mechanism ◽  
Dominance Model ◽  
Proton Proton ◽  
Proton Collisions ◽  
Theoretical Predictions ◽  
Vector Meson Exchange ◽  
Power Measurements ◽  
Proton Proton Collisions

Information about the production mechanism of the η meson in proton-proton collisions can be inferred by confronting the experimental studies on the analysing power for the [Formula: see text] reaction with the theoretical predictions of this observable. The determined analysing powers for Q =10 MeV and Q =36 MeV are consistent with zero. Results show that the predictions of pure pseudoscalar meson exchange model fairly describe the experimental data, while the predictions of pure vector meson exchange dominance model disagree with the data at the level of 4.3 σ.

scholarly journals Multiplicity dependence of (multi-)strange hadron production in proton-proton collisions at $$\sqrt{s}$$ = 13 TeV

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
S. Acharya ◽  
◽  
D. Adamová ◽  
S. P. Adhya ◽  
A. Adler ◽  
...  
Keyword(s):  
Charged Particle ◽  
Charged Particles ◽  
General Purpose ◽  
Particle Multiplicity ◽  
Charged Particle Multiplicity ◽  
Production Rates ◽  
Proton Proton ◽  
Proton Collisions ◽  
Strange Hadron ◽  
Proton Proton Collisions

Abstract The production rates and the transverse momentum distribution of strange hadrons at mid-rapidity ($$\left| y\right| < 0.5$$y<0.5) are measured in proton-proton collisions at $$\sqrt{s}$$s = 13 TeV as a function of the charged particle multiplicity, using the ALICE detector at the LHC. The production rates of $$\mathrm{K}^{0}_{S}$$KS0, $$\Lambda $$Λ, $$\Xi $$Ξ, and $$\Omega $$Ω increase with the multiplicity faster than what is reported for inclusive charged particles. The increase is found to be more pronounced for hadrons with a larger strangeness content. Possible auto-correlations between the charged particles and the strange hadrons are evaluated by measuring the event-activity with charged particle multiplicity estimators covering different pseudorapidity regions. When comparing to lower energy results, the yields of strange hadrons are found to depend only on the mid-rapidity charged particle multiplicity. Several features of the data are reproduced qualitatively by general purpose QCD Monte Carlo models that take into account the effect of densely-packed QCD strings in high multiplicity collisions. However, none of the tested models reproduce the data quantitatively. This work corroborates and extends the ALICE findings on strangeness production in proton-proton collisions at 7 TeV.

scholarly journals Search for new phenomena in photon+jet events collected in proton–proton collisions at s=8 TeV with the ATLAS detector

2014 ◽  
Vol 728 ◽  
pp. 562-578 ◽  
Author(s):  
G. Aad ◽  
T. Abajyan ◽  
B. Abbott ◽  
J. Abdallah ◽  
S. Abdel Khalek ◽  
...  
Keyword(s):  
Atlas Detector ◽  
Proton Proton ◽  
Proton Collisions ◽  
New Phenomena ◽  
Proton Proton Collisions
Sign in / Sign up

Export Citation Format

Share Document