<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mi>K</mml:mi><mml:mo>*</mml:mo></mml:msup><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mn>892</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mo>±</mml:mo></mml:msup></mml:mrow></mml:math> resonance production in Pb-Pb collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:msub><mml:mi>s</mml:mi><mml:mrow><mml:mi>N</mml:mi><mml:mi>N</mml:mi></mml:mrow></mml:msub></mml:msqrt><mml:mo>=</mml:mo><mml:mn>5.02</mml:mn></mml:mrow></mml:math> TeV
S. Acharya, D. Adamová, G. Aglieri Rinella, M. Agnello, N. Agrawal, Z. Ahammed, S. Ahmad, S. U. Ahn, I. Ahuja, A. Akindinov, M. Al-Turany, D. Aleksandrov, B. Alessandro, H. M. Alfanda, R. Alfaro Molina, Bushra Ali, A. Alici, N. Alizadehvandchali, A. Alkin, J. Alme, G. Alocco, T. Alt, Anna Rita Altamura, I. Altsybeev, J. R. Alvarado, M. N. Anaam, C. Andrei, N. Andreou, A. Andronic, V. Anguelov, F. Antinori, P. Antonioli, N. Apadula, L. Aphecetche, H. Appelshäuser, C. Arata, S. Arcelli, M. Aresti, R. Arnaldi, Jhoao Gabriel Martins Campos Almeida Arneiro, I. C. Arsene, M. Arslandok, A. Augustinus, R. Averbeck, M. D. Azmi, H. Baba, A. Badalà, J. Bae, Y. W. Baek, X. Bai, R. Bailhache, Y. Bailung, A. Balbino, A. Baldisseri, Bartosz Baliś, D. Banerjee, Z. Banoo, R. Barbera, F. Barile, L. Barioglio, M. Barlou, Banajit Barman, G. G. Barnaföldi, L. S. Barnby, V. Barret, L. Barreto, C. Bartels, K. Barth, E. Bartsch, N. Bastid, S. Basu, G. Batigne, D. Battistini, B. Batyunya, D. Bauri, J. L. Bazo Alba, I. G. Bearden, C. Beattie, P. Becht, D. Behera, I. Belikov, A. D. C. Bell Hechavarria, F. Bellini, R. Bellwied, S. Belokurova, Yael Antonio Vásquez Beltran, G. Bencédi, S. Beolè, Y. Berdnikov, A. Berdnikova, L. Bergmann, Mihaela Gabriela Besoiu, L. Betev, Partha Pratim Bhaduri, A. Bhasin, M. A. Bhat, B. Bhattacharjee, L. Bianchi, N. Bianchi, J. Bielčík
Abstract
The production of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msup><a:mrow><a:mi>K</a:mi></a:mrow><a:mo>*</a:mo></a:msup><a:msup><a:mrow><a:mo>(</a:mo><a:mn>892</a:mn><a:mo>)</a:mo></a:mrow><a:mo>±</a:mo></a:msup></a:mrow></a:math> meson resonance is measured at midrapidity (<b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mo>|</b:mo><b:mi>y</b:mi><b:mo>|</b:mo><b:mo><</b:mo><b:mn>0.5</b:mn></b:mrow></b:math>) in <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mi>Pb</c:mi><c:mtext>−</c:mtext><c:mi>Pb</c:mi></c:mrow></c:math> collisions at <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mrow><d:msqrt><d:msub><d:mi>s</d:mi><d:mrow><d:mi>N</d:mi><d:mi>N</d:mi></d:mrow></d:msub></d:msqrt><d:mo>=</d:mo><d:mn>5.02</d:mn></d:mrow></d:math> TeV using the ALICE detector at the CERN Large Hadron Collider. The resonance is reconstructed via its hadronic decay channel <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mrow><e:msup><e:mrow><e:mi>K</e:mi></e:mrow><e:mo>*</e:mo></e:msup><e:msup><e:mrow><e:mo>(</e:mo><e:mn>892</e:mn><e:mo>)</e:mo></e:mrow><e:mo>±</e:mo></e:msup><e:mo>→</e:mo><e:mrow><e:msubsup><e:mi>K</e:mi><e:mi mathvariant="normal">S</e:mi><e:mn>0</e:mn></e:msubsup><e:msup><e:mi>π</e:mi><e:mo>±</e:mo></e:msup></e:mrow></e:mrow></e:math>. The transverse momentum distributions are obtained for various centrality intervals in the <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"><g:msub><g:mi>p</g:mi><g:mi mathvariant="normal">T</g:mi></g:msub></g:math> range of <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"><i:mrow><i:mn>0.4</i:mn><i:mtext>−</i:mtext><i:mn>16</i:mn></i:mrow><i:mo> </i:mo><i:mrow><i:mi>GeV</i:mi><i:mo>/</i:mo><i:mi>c</i:mi></i:mrow></i:math>. Measurements of integrated yields, mean transverse momenta, and particle yield ratios are reported and found to be consistent with previous ALICE measurements for <j:math xmlns:j="http://www.w3.org/1998/Math/MathML"><j:mrow><j:msup><j:mrow><j:mi>K</j:mi></j:mrow><j:mo>*</j:mo></j:msup><j:msup><j:mrow><j:mo>(</j:mo><j:mn>892</j:mn><j:mo>)</j:mo></j:mrow><j:mn>0</j:mn></j:msup></j:mrow></j:math> within uncertainties. The <k:math xmlns:k="http://www.w3.org/1998/Math/MathML"><k:msub><k:mi>p</k:mi><k:mi mathvariant="normal">T</k:mi></k:msub></k:math>-integrated yield ratio <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"><m:mrow><m:mn>2</m:mn><m:mspace width="0.16em"/><m:msup><m:mrow><m:mi>K</m:mi></m:mrow><m:mo>*</m:mo></m:msup><m:msup><m:mrow><m:mo>(</m:mo><m:mn>892</m:mn><m:mo>)</m:mo></m:mrow><m:mo>±</m:mo></m:msup><m:mrow><m:mo>/</m:mo><m:mo>(</m:mo></m:mrow><m:mrow><m:msup><m:mi>K</m:mi><m:mo>+</m:mo></m:msup><m:mo>+</m:mo><m:msup><m:mi>K</m:mi><m:mo>−</m:mo></m:msup></m:mrow></m:mrow></m:math>) in central <o:math xmlns:o="http://www.w3.org/1998/Math/MathML"><o:mrow><o:mi>Pb</o:mi><o:mtext>−</o:mtext><o:mi>Pb</o:mi></o:mrow></o:math> collisions shows a significant suppression at a level of <p:math xmlns:p="http://www.w3.org/1998/Math/MathML"><p:mrow><p:mn>9.3</p:mn><p:mi>σ</p:mi></p:mrow></p:math> relative to <q:math xmlns:q="http://www.w3.org/1998/Math/MathML"><q:mrow><q:mi>p</q:mi><q:mi>p</q:mi></q:mrow></q:math> collisions. Thermal model calculations result in an overprediction of the particle yield ratio. Although both hadron resonance gas in partial chemical equilibrium (HRG-PCE) and <r:math xmlns:r="http://www.w3.org/1998/Math/MathML"><r:mo>+</r:mo></r:math> simulations consider the hadronic phase, only HRG-PCE accurately represents the measurements, whereas <s:math xmlns:s="http://www.w3.org/1998/Math/MathML"><s:mo>+</s:mo></s:math> simulations tend to overpredict the particle yield ratio. These observations, along with the kinetic freeze-out temperatures extracted from the yields measured for light-flavored hadrons using the HRG-PCE model, indicate a finite hadronic phase lifetime, which decreases with increasing collision centrality percentile. The <t:math xmlns:t="http://www.w3.org/1998/Math/MathML"><t:msub><t:mi>p</t:mi><t:mi mathvariant="normal">T</t:mi></t:msub></t:math>-differential yield ratios <v:math xmlns:v="http://www.w3.org/1998/Math/MathML"><v:mrow><v:mn>2</v:mn><v:mspace width="0.16em"/><v:msup><v:mrow><v:mi>K</v:mi></v:mrow><v:mo>*</v:mo></v:msup><v:msup><v:mrow><v:mo>(</v:mo><v:mn>892</v:mn><v:mo>)</v:mo></v:mrow><v:mo>±</v:mo></v:msup><v:mrow><v:mo>/</v:mo><v:mo>(</v:mo></v:mrow><v:mrow><v:msup><v:mi>K</v:mi><v:mo>+</v:mo></v:msup><v:mo>+</v:mo><v:msup><v:mi>K</v:mi><v:mo>−</v:mo></v:msup></v:mrow></v:mrow></v:math>) and <x:math xmlns:x="http://www.w3.org/1998/Math/MathML"><x:mrow><x:mn>2</x:mn><x:mspace width="0.16em"/><x:msup><x:mrow><x:mi>K</x:mi></x:mrow><x:mo>*</x:mo></x:msup><x:msup><x:mrow><x:mo>(</x:mo><x:mn>892</x:mn><x:mo>)</x:mo></x:mrow><x:mo>±</x:mo></x:msup><x:mrow><x:mo>/</x:mo><x:mo>(</x:mo></x:mrow><x:mrow><x:msup><x:mi>π</x:mi><x:mo>+</x:mo></x:msup><x:mo>+</x:mo><x:msup><x:mi>π</x:mi><x:mo>−</x:mo></x:msup></x:mrow></x:mrow></x:math>) are presented and compared with measurements in pp collisions at <z:math xmlns:z="http://www.w3.org/1998/Math/MathML"><z:mrow><z:msqrt><z:mi>s</z:mi></z:msqrt><z:mo>=</z:mo><z:mn>5.02</z:mn></z:mrow></z:math> TeV. Both particle ratios are found to be suppressed by up to a factor of five at <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML"><ab:mrow><ab:msub><ab:mi>p</ab:mi><ab:mi mathvariant="normal">T</ab:mi></ab:msub><ab:mo><</ab:mo><ab:mn>2.0</ab:mn></ab:mrow><ab:mo> </ab:mo><ab:mrow><ab:mi>GeV</ab:mi><ab:mo>/</ab:mo><ab:mi>c</ab:mi></ab:mrow></ab:math> in central <cb:math xmlns:cb="http://www.w3.org/1998/Math/MathML"><cb:mrow><cb:mi>Pb</cb:mi><cb:mtext>−</cb:mtext><cb:mi>Pb</cb:mi></cb:mrow></cb:math> collisions and are qualitatively consistent with expectations for rescattering effects in the hadronic phase. The nuclear modification factor (<db:math xmlns:db="http://www.w3.org/1998/Math/MathML"><db:msub><db:mi>R</db:mi><db:mi>AA</db:mi></db:msub></db:math>) shows a smooth evolution with centrality and is found to be below unity at <eb:math xmlns:eb="http://www.w3.org/1998/Math/MathML"><eb:mrow><eb:msub><eb:mi>p</eb:mi><eb:mi mathvariant="normal">T</eb:mi></eb:msub><eb:mo>></eb:mo><eb:mn>8</eb:mn></eb:mrow><eb:mo> </eb:mo><eb:mrow><eb:mi>GeV</eb:mi><eb:mo>/</eb:mo><eb:mi>c</eb:mi></eb:mrow></eb:math>, consistent with measurements for other light-flavored hadrons. The smallest values are observed in most central collisions, indicating larger energy loss of partons traversing the dense medium. ©2024 CERN, for the ALICE Collaboration 2024 CERN