Measurement of the Groomed Jet Radius and Momentum Splitting Fraction in pp and Pb-Pb Collisions at sNN =5.02 TeV

Standard

Measurement of the Groomed Jet Radius and Momentum Splitting Fraction in pp and Pb-Pb Collisions at sNN =5.02 TeV. / ALICE Collaboration.

In: Physical Review Letters, Vol. 128, No. 10, 102001, 11.03.2022.

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

BibTeX

@article{cd29bbfced3f4fbb801ca7a20e18bbfd,

title = "Measurement of the Groomed Jet Radius and Momentum Splitting Fraction in pp and Pb-Pb Collisions at sNN =5.02 TeV",

abstract = "This article presents groomed jet substructure measurements in pp and Pb-Pb collisions at sNN=5.02 TeV with the ALICE detector. The soft drop grooming algorithm provides access to the hard parton splittings inside a jet by removing soft wide-angle radiation. We report the groomed jet momentum splitting fraction, zg, and the (scaled) groomed jet radius, θg. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with resolution parameters R=0.2 and R=0.4. In heavy-ion collisions, the large underlying event poses a challenge for the reconstruction of groomed jet observables, since fluctuations in the background can cause groomed parton splittings to be misidentified. By using strong grooming conditions to reduce this background, we report these observables fully corrected for detector effects and background fluctuations for the first time. A narrowing of the θg distribution in Pb-Pb collisions compared to pp collisions is seen, which provides direct evidence of the modification of the angular structure of jets in the quark-gluon plasma. No significant modification of the zg distribution in Pb-Pb collisions compared to pp collisions is observed. These results are compared with a variety of theoretical models of jet quenching, and provide constraints on jet energy-loss mechanisms and coherence effects in the quark-gluon plasma.",

author = "{ALICE Collaboration} and S. Acharya and D. Adamov{\'a} and A. Adler and {Aglieri Rinella}, G. and M. Agnello and N. Agrawal and Z. Ahammed and S. Ahmad and Ahn, {S. U.} and I. Ahuja and Z. Akbar and A. Akindinov and M. Al-Turany and Alam, {S. N.} and D. Aleksandrov and B. Alessandro and Alfanda, {H. M.} and {Alfaro Molina}, R. and B. Ali and Y. Ali and A. Alici and N. Alizadehvandchali 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 A. Andronic and M. Angeletti and V. Anguelov and F. Antinori and P. Antonioli and C. Anuj and N. Apadula and L. Aphecetche and H. Appelsh{\"a}user and S. Arcelli and R. Arnaldi and S. Belokurova and A. Erokhin and G. Feofilov and V. Kovalenko and T. Lazareva and D. Nesterov and V. Vechernin and A. Zarochentsev and V. Zherebchevskii",

note = "Publisher Copyright: {\textcopyright} 2022 CERN.",

year = "2022",

month = mar,

day = "11",

doi = "10.1103/PhysRevLett.128.102001",

language = "English",

volume = "128",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "10",

}

RIS

TY - JOUR

T1 - Measurement of the Groomed Jet Radius and Momentum Splitting Fraction in pp and Pb-Pb Collisions at sNN =5.02 TeV

AU - ALICE Collaboration

AU - Acharya, S.

AU - Adamová, D.

AU - Adler, A.

AU - Aglieri Rinella, G.

AU - Agnello, M.

AU - Agrawal, N.

AU - Ahammed, Z.

AU - Ahmad, S.

AU - Ahn, S. U.

AU - Ahuja, I.

AU - Akbar, Z.

AU - Akindinov, A.

AU - Al-Turany, M.

AU - Alam, S. N.

AU - Aleksandrov, D.

AU - Alessandro, B.

AU - Alfanda, H. M.

AU - Alfaro Molina, R.

AU - Ali, B.

AU - Ali, Y.

AU - Alici, A.

AU - Alizadehvandchali, N.

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 - Andronic, A.

AU - Angeletti, M.

AU - Anguelov, V.

AU - Antinori, F.

AU - Antonioli, P.

AU - Anuj, C.

AU - Apadula, N.

AU - Aphecetche, L.

AU - Appelshäuser, H.

AU - Arcelli, S.

AU - Arnaldi, R.

AU - Belokurova, S.

AU - Erokhin, A.

AU - Feofilov, G.

AU - Kovalenko, V.

AU - Lazareva, T.

AU - Nesterov, D.

AU - Vechernin, V.

AU - Zarochentsev, A.

AU - Zherebchevskii, V.

PY - 2022/3/11

Y1 - 2022/3/11

N2 - This article presents groomed jet substructure measurements in pp and Pb-Pb collisions at sNN=5.02 TeV with the ALICE detector. The soft drop grooming algorithm provides access to the hard parton splittings inside a jet by removing soft wide-angle radiation. We report the groomed jet momentum splitting fraction, zg, and the (scaled) groomed jet radius, θg. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with resolution parameters R=0.2 and R=0.4. In heavy-ion collisions, the large underlying event poses a challenge for the reconstruction of groomed jet observables, since fluctuations in the background can cause groomed parton splittings to be misidentified. By using strong grooming conditions to reduce this background, we report these observables fully corrected for detector effects and background fluctuations for the first time. A narrowing of the θg distribution in Pb-Pb collisions compared to pp collisions is seen, which provides direct evidence of the modification of the angular structure of jets in the quark-gluon plasma. No significant modification of the zg distribution in Pb-Pb collisions compared to pp collisions is observed. These results are compared with a variety of theoretical models of jet quenching, and provide constraints on jet energy-loss mechanisms and coherence effects in the quark-gluon plasma.

AB - This article presents groomed jet substructure measurements in pp and Pb-Pb collisions at sNN=5.02 TeV with the ALICE detector. The soft drop grooming algorithm provides access to the hard parton splittings inside a jet by removing soft wide-angle radiation. We report the groomed jet momentum splitting fraction, zg, and the (scaled) groomed jet radius, θg. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with resolution parameters R=0.2 and R=0.4. In heavy-ion collisions, the large underlying event poses a challenge for the reconstruction of groomed jet observables, since fluctuations in the background can cause groomed parton splittings to be misidentified. By using strong grooming conditions to reduce this background, we report these observables fully corrected for detector effects and background fluctuations for the first time. A narrowing of the θg distribution in Pb-Pb collisions compared to pp collisions is seen, which provides direct evidence of the modification of the angular structure of jets in the quark-gluon plasma. No significant modification of the zg distribution in Pb-Pb collisions compared to pp collisions is observed. These results are compared with a variety of theoretical models of jet quenching, and provide constraints on jet energy-loss mechanisms and coherence effects in the quark-gluon plasma.

UR - http://www.scopus.com/inward/record.url?scp=85126714754&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.128.102001

DO - 10.1103/PhysRevLett.128.102001

M3 - Article

C2 - 35333086

AN - SCOPUS:85126714754

VL - 128

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 10

M1 - 102001

ER -

ID: 94895350