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

Kód výsledku v 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>

Nalezeny alternativní kódy

RIV/68407700:21340/20:00346310

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Journal of High Energy Physics

ISSN

1029-8479

e-ISSN

—

Svazek periodika

2020

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

46

Strana od-do

178

Kód UT WoS článku

000553028400001

EID výsledku v databázi Scopus

2-s2.0-85089773182