scholarly journals Femtoscopic and Nonfemtoscopic Two-Particle Correlations inA+Aandp+pCollisions at RHIC and LHC Energies

2013 ◽  
Vol 2013 ◽  
pp. 1-23 ◽  
Author(s):  
Yu. M. Sinyukov ◽  
S. V. Akkelin ◽  
Iu. A. Karpenko ◽  
V. M. Shapoval
Keyword(s):  
Correlation Function ◽  
Simple Model ◽  
Proton Proton ◽  
Proton Collisions ◽  
Basic Model ◽  
Kaon Interferometry ◽  
Bose Einstein ◽  
Proton Proton Collisions ◽  
Theoretical Results ◽  
Einstein Correlation

The theoretical review of the last femtoscopy results for the systems created in ultrarelativisticA+A,p+p, andp+Pbcollisions is presented. The basic model, allowing to describe the interferometry data at SPS, RHIC, and LHC, is the hydrokinetic model. The model allows one to avoid the principal problem of the particlization of the medium at nonspace-like sites of transition hypersurfaces and switch to hadronic cascade at a space-like hypersurface with nonequilibrated particle input. The results for pion and kaon interferometry scales inPb+PbandAu+Aucollisions at LHC and RHIC are presented for different centralities. The new theoretical results as for the femtoscopy of small sources with sizes of 1-2 fm or less are discussed. The uncertainty principle destroys the standard approach of completely chaotic sources: the emitters in such sources cannot radiate independently and incoherently. As a result, the observed femtoscopy scales are reduced, and the Bose-Einstein correlation function is suppressed. The results are applied for the femtoscopy analysis ofp+pcollisions ats=7 TeV LHC energy andp+Pbones ats=5.02 TeV. The behavior of the corresponding interferometry volumes on multiplicity is compared with what is happening for centralA+Acollisions. In addition the nonfemtoscopic two-pion correlations in proton-proton collisions at the LHC energies are considered, and a simple model that takes into account correlations induced by the conservation laws and minijets is analyzed.

scholarly journals Timepix3 Luminosity Determination of 13 TeV Proton-Proton Collisions at the ATLAS Experiment

2020 ◽  
Vol 225 ◽  
pp. 01002
Author(s):  
Andreé Sopczak
Keyword(s):  
Simple Model ◽  
Number Of Clusters ◽  
Proton Proton ◽  
Proton Collisions ◽  
Atlas Experiment ◽  
Long Term Stability ◽  
Counting Methods ◽  
Proton Proton Collisions

Medipix and Timepix devices, installed in the ATLAS cavern at the LHC, have provided valuable complementary luminosity information. Results are presented from measurements with Timepix3 (TPX3) detectors. In contrast with previously employed frame-based data acquisition, the TPX3 detector remains active continuously, sending information on pixel hits as they occur. Hit- and cluster-counting methods were used for the luminosity determination of the LHC protonproton collisions. The LHC luminosity versus time is determined using these two methods and fitted to a simple model, which incorporates luminosity reduction from single bunch and beam-beam interactions. The precision of the luminosity determination could be improved by counting the number of clusters, instead of just pixel hits. The internal precision and long-term stability of the TPX3 luminosity measurement are below 0.5%. TPX3, owing to its 1.56 ns time-tagging, is able to resolve the time structure of the luminosity due to the collisions of individual proton bunches when integrated over an LHC fill.

scholarly journals Tensor pomeron, vector odderon and diffractive production of meson and baryon pairs in proton-proton collisions

2019 ◽  
Vol 206 ◽  
pp. 06005 ◽  
Author(s):  
Piotr Lebiedowicz ◽  
Otto Nachtmann ◽  
Antoni Szczurek
Keyword(s):  
Experimental Data ◽  
High Energy ◽  
Proton Proton ◽  
Proton Collisions ◽  
High Energies ◽  
Energy Proton ◽  
Diffractive Production ◽  
Proton Proton Collisions ◽  
Theoretical Results ◽  
The Continuum

We review some selected results of the tensor-pomeron and vectorodderon model of soft high-energy proton-proton scattering and central exclusive production of meson and baryon pairs in proton-proton collisions. We discuss the theoretical aspects of this approach and consider the phenomenological implications in a variety of processes at high energies, comparing to existing experimental data. We consider the diffractive dipion and dikaon production including the continuum and the dominant scalar and tensor resonance contributions as well as the photoproduction processes. The theoretical results are compared with existing CDF experimental data and predictions for planned or current LHC experiments, ALICE, ATLAS, CMS, LHCb are presented.

scholarly journals First Measurement of Bose-Einstein Correlations in Proton-Proton Collisions ats=0.9and 2.36 TeV at the LHC

2010 ◽  
Vol 105 (3) ◽  
Author(s):  
V. Khachatryan ◽  
A. M. Sirunyan ◽  
A. Tumasyan ◽  
W. Adam ◽  
T. Bergauer ◽  
...  
Keyword(s):  
Proton Proton ◽  
Proton Collisions ◽  
Bose Einstein ◽  
Proton Proton Collisions

η PRODUCTION IN PROTON-PROTON COLLISIONS AT 72 MeV EXCESS ENERGY

2009 ◽  
Vol 24 (02n03) ◽  
pp. 446-449
Author(s):  
◽  
H. PETTERSSON ◽  
M. BASHKANOV ◽  
D. BOGOSLOWSKY ◽  
H. CALÉN ◽  
...  
Keyword(s):  
Simple Model ◽  
Strong Influence ◽  
Excess Energy ◽  
Exchange Model ◽  
Final States ◽  
Proton Proton ◽  
Proton Collisions ◽  
Boson Exchange ◽  
Proton Proton Collisions ◽  
Better Than

The production of η mesons at an excess energy of 72 MeV has been studied in the reaction pp → pp(η)γγ. It is shown that a simple model with Pp final states included reproduces observed differential distributions better than the same model restricted to Ss , Sd and Ds final states. The strong influence of the Pp states could be taken as an indication of ρ dominance within an one boson exchange model for the excitation of N *(1535).

η MESON PRODUCTION IN PROTON-PROTON COLLISIONS AT 40 AND 72 MeV EXCESS ENERGY

2011 ◽  
Vol 26 (03n04) ◽  
pp. 681-682
Author(s):  
◽  
HENRIK PETRÉN
Keyword(s):  
Angular Momentum ◽  
Simple Model ◽  
Cross Sections ◽  
Meson Production ◽  
Excess Energy ◽  
Proton Proton ◽  
Proton Collisions ◽  
Mass Distributions ◽  
Partial Waves ◽  
Proton Proton Collisions

Differential cross sections for η production in proton-proton collisions at 40 and 72 MeV above threshold show that higher partial waves are necessary to describe the reaction. A simple model assuming constant production amplitudes and including most partial waves up to two units of angular momentum reproduces the data rather well, and also describes the invariant mass distributions found at 15.5 MeV excess energy.

scholarly journals Central exclusive production of K+K− pairs in proton-proton collisions

2019 ◽  
Vol 199 ◽  
pp. 03005
Author(s):  
Piotr Lebiedowicz ◽  
Antoni Szczurek ◽  
Otto Nachtmann
Keyword(s):  
Experimental Data ◽  
Pseudoscalar Meson ◽  
Interference Effects ◽  
Central Exclusive Production ◽  
Proton Proton ◽  
Proton Collisions ◽  
Exclusive Production ◽  
Diffractive Production ◽  
Proton Proton Collisions ◽  
Theoretical Results

We discuss central exclusive diffractive production of light mesons in the reactions $pp \to pp{\pi ^ + }{\pi ^ - }$ and $pp \to pp{K^ + }{K^ - }$. The calculation is based on a tensor-pomeron approach. We include a purely diffractive dipion continuum, and the scalar f0(980), f0(1500), f0(1710) and tensor f2(1770), ${f^{\prime}_2}(1525)$ resonances decaying into pseudoscalar meson pairs. We include also photoproduction mechanisms for the nonresonant (Drell-Söding) and the ϕ(1020) resonance contributions. The theoretical results are compared with existing CDF experimental data and predictions for being carried out LHC experiments are presented. The distributions in dimeson invariant mass and in a special "glueball filter variable" including the interference effects of resonance and dimeson continuum are presented.

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