Abstract
Bose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at sqrt{s} = 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at sqrt{s} = 7 TeV, as well as with theoretical predictions.
Highlights
For the purpose of evaluating and removing such cluster effects, the one-dimensional opposite-sign (OS) SR correlation functions are fitted with the expression in eq (A.2), which describes the data in all kT and Ntorfflk ine ranges, C2(+−)(qinv) = c b 1 + √ exp σb 2π qi2nv 2σb2 (1 + qinv), (A.2)
In previous CMS analyses [4, 5], the presence of an anticorrelation in the BEC functions was reported in pp collisions with characteristics that did not show a clear dependence on the center-of-mass energy
Prior to its observation in pp collisions, this anticorrelation had been seen in e+e− collisions [69], with features compatible with a description provided by the τ -model [70], in which particle production has a broad distribution in proper time and the phase space distribution of the emitted particles is dominated by strong correlations of the spacetime coordinate and momentum components
Summary
The central feature of the CMS detector is a superconducting solenoid of 6 m internal diameter. In addition to the barrel and endcap detectors, quartz-fiber Cherenkov hadron forward (HF) calorimeters (3 < |η| < 5) complement the coverage provided by the barrel and endcap detectors on both sides of the interaction point. These HF calorimeters are azimuthally subdivided into 20◦ modular wedges and further segmented to form 0.175×0.175 (∆η×∆φ) “towers”. The silicon tracker measures charged particles within the pseudorapidity range |η| < 2.5 It consists of 1440 silicon pixel and 15 148 silicon strip detector modules. A detailed description of the CMS detector, together with a definition of the coordinate system and kinematic variables, can be found in ref. [29]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
