Measurement of Prompt <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi mathvariant="normal">Λ</mml:mi><mml:mi>c</mml:mi><mml:mo>+</mml:mo></mml:msubsup></mml:math>, and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi mathvariant="normal">Σ</mml:mi><mml:mi>c</mml:mi><mml:mrow><mml:mn>0</mml:mn><mml:mo>,</mml:mo><mml:mo>+</mml:mo><mml:mo>+</mml:mo></mml:mrow></mml:msubsup><mml:mo stretchy="false">(</mml:mo><mml:mn>2455</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math> Production in Proton-Proton Collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:math>
S. Acharya, D. Adamová, A. Adler, J. Adolfsson, G. Aglieri Rinella, M. Agnello, N. Agrawal, Z. Ahammed, S. Ahmad, S. U. Ahn, I. Ahuja, Zaenal Akbar, A. Akindinov, M. Al-Turany, S. N. Alam, D. Aleksandrov, B. Alessandro, H. M. Alfanda, R. Alfaro Molina, B. Ali, Y. Ali, A. Alici, N. Alizadehvandchali, A. Alkin, J. Alme, T. Alt, L. Altenkamper, I. Altsybeev, M. N. Anaam, C. Andrei, D. Andreou, A. Andronic, M. Angeletti, V. Anguelov, F. Antinori, P. Antonioli, C. Anuj, N. Apadula, L. Aphecetche, H. Appelshäuser, S. Arcelli, R. Arnaldi, I. C. Arsene, M. Arslandok, A. Augustinus, R. Averbeck, S. Aziz, M. D. Azmi, A. Badalà, Y. W. Baek, Xiaozhi Bai, R. Bailhache, Y. Bailung, R. Bala, A. Balbino, A. Baldisseri, Bartosz Baliś, M. Ball, D. Banerjee, R. Barbera, L. Barioglio, M. Barlou, G. G. Barnaföldi, L. S. Barnby, V. Barret, C. Bartels, K. Barth, E. Bartsch, F. Baruffaldi, N. Bastid, S. Basu, G. Batigne, B. Batyunya, D. Bauri, J. L. Bazo Alba, I. G. Bearden, C. Beattie, I. Belikov, A. D. C. Bell Hechavarria, F. Bellini, R. Bellwied, S. Belokurova, V. Belyaev, G. Bencedi, S. Beolè, A. Bercuci, Y. Berdnikov, A. Berdnikova, L. Bergmann, M. G. Besoiu, L. Betev, P. P. Bhaduri, A. Bhasin, M. A. Bhat, B. Bhattacharjee, P. Bhattacharya, L. Bianchi, N. Bianchi, J. Bielčík, J. Bielčíková
Abstract
The ${p}_{T}$-differential production cross sections of prompt ${D}^{0}$, ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$, and ${\mathrm{\ensuremath{\Sigma}}}_{c}^{0,++}(2455)$ charmed hadrons are measured at midrapidity ($|y|<0.5$) in $pp$ collisions at $\sqrt{s}=13\text{ }\text{ }\mathrm{TeV}$. This is the first measurement of ${\mathrm{\ensuremath{\Sigma}}}_{c}^{0,++}$ production in hadronic collisions. Assuming the same production yield for the three ${\mathrm{\ensuremath{\Sigma}}}_{c}^{0,+,++}$ isospin states, the baryon-to-meson cross section ratios ${\mathrm{\ensuremath{\Sigma}}}_{c}^{0,+,++}/{D}^{0}$ and ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}/{D}^{0}$ are calculated in the transverse momentum (${p}_{T}$) intervals $2<{p}_{T}<12$ and $1<{p}_{T}<24\text{ }\mathrm{GeV}/c$. Values significantly larger than in ${e}^{+}{e}^{\ensuremath{-}}$ collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the ${\mathrm{\ensuremath{\Sigma}}}_{c}$. The feed-down contribution to ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$ production from ${\mathrm{\ensuremath{\Sigma}}}_{c}^{0,+,++}$ is also reported and is found to be larger than in ${e}^{+}{e}^{\ensuremath{-}}$ collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronization mechanisms implemented in the models.