Measurement of the central exclusive production of charged particle pairs in proton-proton collisions at root s=200 GeV with the STAR detector at RHIC

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F20%3A00531567" target="_blank" >RIV/61389005:_____/20:00531567 - isvavai.cz</a>

Alternative codes found

RIV/68407700:21340/20:00346310

Result on the web

<a href="https://doi.org/10.1007/JHEP07(2020)178" target="_blank" >https://doi.org/10.1007/JHEP07(2020)178</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/JHEP07(2020)178" target="_blank" >10.1007/JHEP07(2020)178</a>

Result language

angličtina

Original language name

Measurement of the central exclusive production of charged particle pairs in proton-proton collisions at root s=200 GeV with the STAR detector at RHIC

Original language description

We report on the measurement of the Central Exclusive Production of charged particle pairs h(+)h(-) (h = pi, K, p) with the STAR detector at RHIC in proton-proton collisions at root s = 200 GeV. The charged particle pairs produced in the reaction pp -> p' + h(+) h(-) + p' are reconstructed from the tracks in the central detector and identified using the specific energy loss and the time of flight method, while the forward-scattered protons are measured in the Roman Pot system. Exclusivity of the event is guaranteed by requiring the transverse momentum balance of all four final-state particles. Differential cross sections are measured as functions of observables related to the central hadronic final state and to the forward-scattered protons. They are measured in a fiducial region corresponding to the acceptance of the STAR detector and determined by the central particles' transverse momenta and pseudorapidities as well as by the forward-scattered protons' momenta. This fiducial region roughly corresponds to the square of the four-momentum transfers at the proton vertices in the range 0:04 GeV2 < -t(1), -t(2) < 0:2 GeV2, invariant masses of the charged particle pairs up to a few GeV and pseudorapidities of the centrallyproduced hadrons in the range vertical bar eta vertical bar < 0:7. The measured cross sections are compared to phenomenological predictions based on the Double Pomeron Exchange (DPE) model. Structures observed in the mass spectra of pi(+)pi(-) and K+K- pairs are consistent with the DPE model, while angular distributions of pions suggest a dominant spin-0 contribution to pi(+)pi(-)production. For pi(+)pi(-) production, the fiducial cross section is extrapolated to the Lorentz-invariant region, which allows decomposition of the invariant mass spectrum into continuum and resonant contributions. The extrapolated cross section is well described by the continuum production and at least three resonances, the f(0) (980), f(2) (1270) and f(0)(1500), with a possible small contribution from the f(0)(1370). Fits to the extrapolated differential cross section as a function of t(1) and t(2) enable extraction of the exponential slope parameters in several bins of the invariant mass of pi(+)pi(-) pairs. These parameters are sensitive to the size of the interaction region.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10303 - Particles and field physics

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of High Energy Physics

ISSN

1029-8479

e-ISSN

—

Volume of the periodical

2020

Issue of the periodical within the volume

7

Country of publishing house

US - UNITED STATES

Number of pages

46

Pages from-to

178

UT code for WoS article

000553028400001

EID of the result in the Scopus database

2-s2.0-85089773182