Event-shape and multiplicity dependence of freeze-out radii in pp collisions at √s = 7 TeV

Standard

Event-shape and multiplicity dependence of freeze-out radii in pp collisions at √s = 7 TeV. / ALICE Collaboration ; Феофилов, Григорий Александрович.

In: Journal of High Energy Physics, Vol. 2019, No. 9, 108, 01.09.2019.

Research output: Contribution to journal › Article › peer-review

BibTeX

@article{c274dfce4c5e4a91bf051871afe02dbb,

title = "Event-shape and multiplicity dependence of freeze-out radii in pp collisions at √s = 7 TeV",

abstract = "Two-particle correlations in high-energy collision experiments enable the extraction of particle source radii by using the Bose-Einstein enhancement of pion production at low relative momentum q proportional to 1/R. It was previously observed that in pp collisions at root s = 7 TeV the average pair transverse momentum k(T) range of such analyses is limited due to large background correlations which were attributed to mini-jet phenomena. To investigate this further, an event-shape dependent analysis of Bose-Einstein correlations for pion pairs is performed in this work. By categorizing the events by their transverse sphericity S-T into spherical (S-T > 0.7) and jet-like (S-T <0.3) events a method was developed that allows for the determination of source radii for much larger values of k(T) for the first time. Spherical events demonstrate little or no background correlations while jet-like events are dominated by them. This observation agrees with the hypothesis of a mini-jet origin of the non-femtoscopic background correlations and gives new insight into the physics interpretation of the k(T) dependence of the radii. The emission source size in spherical events shows a substantially diminished k(T) dependence, while jet-like events show indications of a negative trend with respect to k(T) in the highest multiplicity events. Regarding the emission source shape, the correlation functions for both event sphericity classes show good agreement with an exponential shape, rather than a Gaussian one.",

keywords = "Heavy Ion Experiments, Particle correlations and fluctuations, INTERFEROMETRY",

author = "{ALICE Collaboration} and S. Acharya and D. Adamova and Adhya, {S. P.} and A. Adler and J. Adolfsson and Aggarwal, {M. M.} and Rinella, {G. Aglieri} and M. Agnello and N. Agrawal and Z. Ahammed and S. Ahmad and Ahn, {S. U.} and S. Aiola and A. Akindinov and M. Al-Turany and Alam, {S. N.} and Albuquerque, {D. S. D.} and D. Aleksandrov and B. Alessandro and Alfanda, {H. M.} and Molina, {R. Alfaro} and Y. Ali and A. Alici and A. Alkin and J. Alme and T. Alt and L. Altenkamper and I. Altsybeev and Anaam, {M. N.} and C. Andrei and D. Andreou and Andrews, {H. A.} and A. Andronic and M. Angeletti and V. Anguelov and C. Anson and T. Anticic and F. Antinori and P. Antonioli and R. Anwar and N. Apadula and L. Aphecetche and Auser, {H. Appelsh} and S. Arcelli and A. Erokhin and V. Kovalenko and T. Lazareva and V. Vechernin and A. Zarochentsev and V. Zherebchevskii and Феофилов, {Григорий Александрович}",

year = "2019",

month = sep,

day = "1",

doi = "10.1007/JHEP09(2019)108",

language = "Английский",

volume = "2019",

journal = "Journal of High Energy Physics",

issn = "1126-6708",

publisher = "Springer Nature",

number = "9",

}

RIS

TY - JOUR

T1 - Event-shape and multiplicity dependence of freeze-out radii in pp collisions at √s = 7 TeV

AU - ALICE Collaboration

AU - Acharya, S.

AU - Adamova, D.

AU - Adhya, S. P.

AU - Adler, A.

AU - Adolfsson, J.

AU - Aggarwal, M. M.

AU - Rinella, G. Aglieri

AU - Agnello, M.

AU - Agrawal, N.

AU - Ahammed, Z.

AU - Ahmad, S.

AU - Ahn, S. U.

AU - Aiola, S.

AU - Akindinov, A.

AU - Al-Turany, M.

AU - Alam, S. N.

AU - Albuquerque, D. S. D.

AU - Aleksandrov, D.

AU - Alessandro, B.

AU - Alfanda, H. M.

AU - Molina, R. Alfaro

AU - Ali, Y.

AU - Alici, A.

AU - Alkin, A.

AU - Alme, J.

AU - Alt, T.

AU - Altenkamper, L.

AU - Altsybeev, I.

AU - Anaam, M. N.

AU - Andrei, C.

AU - Andreou, D.

AU - Andrews, H. A.

AU - Andronic, A.

AU - Angeletti, M.

AU - Anguelov, V.

AU - Anson, C.

AU - Anticic, T.

AU - Antinori, F.

AU - Antonioli, P.

AU - Anwar, R.

AU - Apadula, N.

AU - Aphecetche, L.

AU - Auser, H. Appelsh

AU - Arcelli, S.

AU - Erokhin, A.

AU - Kovalenko, V.

AU - Lazareva, T.

AU - Vechernin, V.

AU - Zarochentsev, A.

AU - Zherebchevskii, V.

AU - Феофилов, Григорий Александрович

PY - 2019/9/1

Y1 - 2019/9/1

N2 - Two-particle correlations in high-energy collision experiments enable the extraction of particle source radii by using the Bose-Einstein enhancement of pion production at low relative momentum q proportional to 1/R. It was previously observed that in pp collisions at root s = 7 TeV the average pair transverse momentum k(T) range of such analyses is limited due to large background correlations which were attributed to mini-jet phenomena. To investigate this further, an event-shape dependent analysis of Bose-Einstein correlations for pion pairs is performed in this work. By categorizing the events by their transverse sphericity S-T into spherical (S-T > 0.7) and jet-like (S-T <0.3) events a method was developed that allows for the determination of source radii for much larger values of k(T) for the first time. Spherical events demonstrate little or no background correlations while jet-like events are dominated by them. This observation agrees with the hypothesis of a mini-jet origin of the non-femtoscopic background correlations and gives new insight into the physics interpretation of the k(T) dependence of the radii. The emission source size in spherical events shows a substantially diminished k(T) dependence, while jet-like events show indications of a negative trend with respect to k(T) in the highest multiplicity events. Regarding the emission source shape, the correlation functions for both event sphericity classes show good agreement with an exponential shape, rather than a Gaussian one.

AB - Two-particle correlations in high-energy collision experiments enable the extraction of particle source radii by using the Bose-Einstein enhancement of pion production at low relative momentum q proportional to 1/R. It was previously observed that in pp collisions at root s = 7 TeV the average pair transverse momentum k(T) range of such analyses is limited due to large background correlations which were attributed to mini-jet phenomena. To investigate this further, an event-shape dependent analysis of Bose-Einstein correlations for pion pairs is performed in this work. By categorizing the events by their transverse sphericity S-T into spherical (S-T > 0.7) and jet-like (S-T <0.3) events a method was developed that allows for the determination of source radii for much larger values of k(T) for the first time. Spherical events demonstrate little or no background correlations while jet-like events are dominated by them. This observation agrees with the hypothesis of a mini-jet origin of the non-femtoscopic background correlations and gives new insight into the physics interpretation of the k(T) dependence of the radii. The emission source size in spherical events shows a substantially diminished k(T) dependence, while jet-like events show indications of a negative trend with respect to k(T) in the highest multiplicity events. Regarding the emission source shape, the correlation functions for both event sphericity classes show good agreement with an exponential shape, rather than a Gaussian one.

KW - Heavy Ion Experiments

KW - Particle correlations and fluctuations

KW - INTERFEROMETRY

UR - http://www.scopus.com/inward/record.url?scp=85074488241&partnerID=8YFLogxK

U2 - 10.1007/JHEP09(2019)108

DO - 10.1007/JHEP09(2019)108

M3 - статья

VL - 2019

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1126-6708

IS - 9

M1 - 108

ER -

ID: 48561365