scholarly journals Comparative study of charged multiplicities and moments in pp collisions at s=7  TeV in the forward region at the LHC

2020 ◽  
Vol 102 (5) ◽  
Author(s):  
R. Aggarwal ◽  
M. Kaur
2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Emily Nurse ◽  
Sercan Sen

In proton-proton (pp) collisions, any process involves exchanging the vacuum quantum numbers is known as diffractive process. A diffractive process with no largeQ2is called soft diffractive process. The diffractive processes are important for understanding nonperturbative QCD effects and they also constitute a significant fraction of the total pp cross section. The diffractive events are typically characterized by a region of the detector without particles, known as a rapidity gap. In order to observe diffractive events in this way, we consider the pseudorapidity acceptance in the forward region of the ATLAS and CMS detectors at the Large Hadron Collider (LHC) and discuss the methods to select soft diffractive dissociation for pp collisions ats=7 TeV. It is shown that, in the limited detector rapidity acceptance, it is possible to select diffractive dissociation events by requiring a rapidity gap in the event; however, without using forward detectors, it seems not possible to fully separate single and double diffractive dissociation events. The Zero Degree Calorimeters can be used to distinguish the type of the diffractive processes up to a certain extent.


2016 ◽  
Vol 40 ◽  
pp. 1660024
Author(s):  
Christopher J. Dilks

Longitudinally polarized [Formula: see text] scattering experiments provide access to gluon polarization via measurement of the double helicity asymmetry, [Formula: see text]. At the completion of the 2013 RHIC running period, a significant dataset of [Formula: see text]s corresponding to an integrated luminosity of 46 [Formula: see text] (2012) and 8 [Formula: see text] (2013) produced from polarized [Formula: see text] scattering at [Formula: see text] GeV with an average beam polarization of approximately [Formula: see text] was acquired. The [Formula: see text] kinematics were measured via isolation cones by the STAR Forward Meson Spectrometer, an electromagnetic calorimeter covering a forward pseudorapidity range of [Formula: see text]. The asymmetric [Formula: see text] subprocess becomes more dominant in this forward region than in the midrapidity region; furthermore, asymmetry measurements in the forward region are sensitive to low-[Formula: see text] gluons. Progress on [Formula: see text] determined from forward [Formula: see text] events, complementing previous midrapidity measurements, are presented.


2020 ◽  
Vol 44 (3) ◽  
pp. 034104
Author(s):  
Yu-Liang Yan ◽  
Ayut Limphirat ◽  
Dai-Mei Zhou ◽  
Pornrad Srisawad ◽  
Yupeng Yan ◽  
...  

2015 ◽  
Vol 2015 (1) ◽  
Author(s):  
R. Aaij ◽  
◽  
B. Adeva ◽  
M. Adinolfi ◽  
A. Affolder ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Swarnapratim Bhattacharyya ◽  
Maria Haiduc ◽  
Alina Tania Neagu ◽  
Elena Firu

A detailed study of energy dependence of K+/π+, K-/π- and total kaon to pion multiplicity ratio K++K-/π++π-=K/π has been carried out in proton-proton (pp) collisions at s=6.3, 17.3, 62.4, 200, and 900 GeV and also at s=2.76 TeV and 7 TeV in the framework of UrQMD and DPMJET III model. Dependence of K+/π+ and K-/π- on energy shows different behavior for UrQMD and DPMJET III model. The presence of the horn-like structure in the variation of K+/π+ and K-/π- with energy for the experimental data is supported by the DPMJET III model. Experimentally it has been observed that as energy increases, the total kaon to pion multiplicity ratio K++K-/π++π-=K/π increases systematically for pp collisions at lower energies and becomes independent of energy in LHC energy regime. Our analysis on total kaon to pion multiplicity ratio K++K-/π++π-=K/π with UrQMD data is well supported by the experimental results obtained by different collaborations in different times. In case of DPMJET III data, the saturation of K/π ratio at LHC region has not been observed.


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