At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP)(1). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed(2-6). Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions(7), is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton-proton (pp) collisions(8,9), but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton-proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p-Pb collision results(10,11), indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb-Pb collisions, where a QGP is formed.

Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions / Adam, J., Adamova, D., Aggarwal, M.M., Rinella, G.A., Agnello, M., Agrawal, N., Ahammed, Z., Ahmad, S., Ahn, S.U., Aiola, S., Akindinov, A., Alam, S.N., Albuquerque, D.S.D., Aleksandrov, D., Alessandro, B., Alexandre, D., Molina, R.A., Alici, A., Alkin, A., Alme, J., et al.. - In: NATURE PHYSICS. - ISSN 1745-2473. - 13:6(2017), pp. 535-539. [10.1038/NPHYS4111]

Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions

Cunqueiro, L.;Meddi, F.;
2017

Abstract

At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP)(1). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed(2-6). Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions(7), is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton-proton (pp) collisions(8,9), but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton-proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p-Pb collision results(10,11), indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb-Pb collisions, where a QGP is formed.
2017
P-pb collisions; range angular-correlations; heavy-ion collisions; root-S(NN)=5.02 TEV; long-range; energy-dependence baryon production mid-rapidity; PPB; LHC
01 Pubblicazione su rivista::01a Articolo in rivista
Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions / Adam, J., Adamova, D., Aggarwal, M.M., Rinella, G.A., Agnello, M., Agrawal, N., Ahammed, Z., Ahmad, S., Ahn, S.U., Aiola, S., Akindinov, A., Alam, S.N., Albuquerque, D.S.D., Aleksandrov, D., Alessandro, B., Alexandre, D., Molina, R.A., Alici, A., Alkin, A., Alme, J., et al.. - In: NATURE PHYSICS. - ISSN 1745-2473. - 13:6(2017), pp. 535-539. [10.1038/NPHYS4111]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1077240
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