DILEPTON ANALYSIS IN THE HADES SPECTROMETER FOR 12C+12C AT 2 AGEV

The identification of the light mesons in the HADES spectrometer is based on an invariant mass reconstruction of their decay into e+e- pairs. In the dilepton (e+e-) signal reconstruction, particularly important is the reduction of a huge combinatorial background arising from wrong combinations of e+ and e- to unlike sign pairs. Methods of the dilepton signal and combinatorial background reconstruction in the HADES spectrometer will be presented.

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Improved Event Mixing for Resonance Yield Extraction

Proceedings ◽

10.3390/proceedings2019010026 ◽

2019 ◽

Vol 10 (1) ◽

pp. 26

Author(s):

Adrian Fereydon Nassirpour

Keyword(s):

Invariant Mass ◽

New Method ◽

Combinatorial Background ◽

Proton Proton ◽

Proton Collisions ◽

Particle Pairs ◽

Proton Proton Collisions

Resonance particles, such as the K*(892) meson, are reconstructed from the invariant mass (M i n v ) distribution of possible particle pairs. To extract the yield with the highest precision, the combinatorial background must be determined as precisely as possible. An event-mixed M i n v distribution is often used to describe the combinatorial background. However, this distribution will not contain the mini-jet-like structures present inside an event. This analysis introduces a new re-weighing scheme, where two M i n v distributions of like-sign particles in the same-event and in mixed-events are used to correct the mixed-event background estimate for the mini-jet-like structure. Using PYTHIA 8.2 generated proton-proton collisions at s NN = 5.02 TeV, it is shown that the new method can be used to more accurately describe the combinatorial background.

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Invariant mass reconstruction of theηmeson in the decay channelπ+π−π0with the REDTOP experiment

Journal of Physics Conference Series ◽

10.1088/1742-6596/912/1/012034 ◽

2017 ◽

Vol 912 ◽

pp. 012034

Author(s):

S. D. Escobar Martínez ◽

B. Fabela Enríquez ◽

M. I. Pedraza Morales ◽

Keyword(s):

Invariant Mass ◽

Mass Reconstruction

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PROJECTION OF A MEASUREMENT OF THE NONPHOTONIC ELECTRON v2 IN Au + Au COLLISIONS AT STAR

International Journal of Modern Physics E ◽

10.1142/s0218301311019507 ◽

2011 ◽

Vol 20 (08) ◽

pp. 1701-1708

Author(s):

BING-CHU HUANG ◽

YI-FEI ZHANG ◽

ZI-PING ZHANG ◽

ZHANG-BU XU ◽

XIN DONG

Keyword(s):

Invariant Mass ◽

Time Projection Chamber ◽

Time Of Flight ◽

Heavy Flavor ◽

Combinatorial Background ◽

Plane Method ◽

Event Plane ◽

Quark Decays ◽

Time Projection ◽

Star Detector

We present a method of measuring the elliptic flow (v2) of nonphotonic electrons from heavy flavor quark decays using the STAR detector at RHIC in Au + Au collisions at [Formula: see text]. Inclusive electrons are identified in the pT range 0.5–4 GeV /c at mid-rapidity -1 < η < 0 by the STAR time projection chamber (TPC) and time-of-flight detector. Photonic e+e- pairs with characteristic low invariant mass are reconstructed in the TPC and their v2 is measured using the standard event plane method by subtracting the combinatorial background in the dN/dΔϕ distributions in each pT bin. The nonphotonic electron v2 and its propagated error can be derived from the inclusive and photonic electron v2. We estimate the necessary statistics and errors of nonphotonic electron v2 for a more recent RHIC run.

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SHORT LIVED RESONANCES IN ALICE

International Journal of Modern Physics E ◽

10.1142/s0218301307008100 ◽

2007 ◽

Vol 16 (07n08) ◽

pp. 2463-2469 ◽

Cited By ~ 1

Author(s):

A. BADALÀ ◽

R. BARBERA ◽

F. BLANCO ◽

A. PULVIRENTI ◽

F. RIGGI ◽

...

Keyword(s):

Invariant Mass ◽

Decay Product ◽

Hadronic Decay ◽

Particle Identification ◽

Combinatorial Background ◽

Mass Analysis

The ability of the ALICE detector to reconstruct the K*(892)0 resonance in p – p and Pb – Pb collisions at LHC energies has been investigated, by means of a detailed study of simulated events. PYTHIA events for p – p collisions and HIJING events for Pb – Pb collisions have been generated and fully reconstructed. The K*(892)0 was identified by its hadronic decay into Kπ through invariant mass analysis. The combinatorial background has been estimated using an event-mixing technique for p – p events and a like-sign technique for the Pb – Pb ones. The role of the particle identification of the decay product is also discussed.

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