A measurement of the $CP$ asymmetry difference in $\varLambda_{c}^{+} \to pK^{-}K^{+}$ and $p\pi^{-}\pi^{+}$ decays

• Published in: The journal of high energy physics 2018, Vol.3
• Main Authors: Aaij, R., Adeva, Bernardo, Adinolfi, Marco, Ajaltouni, Ziad, Akar, Simon, Albrecht, Johannes, Alessio, Federico, Alexander, Michael, Alfonso Albero, Alejandro, Ali, Suvayu, Alkhazov, Georgy, Alvarez Cartelle, Paula, Alves, Antonio Augusto, Amato, Sandra, Amerio, Silvia, Amhis, Yasmine, An, Liupan, Anderlini, Lucio, Andreassi, Guido, Andreotti, Mirco, Andrews, Jason, Appleby, Robert, Archilli, Flavio, d'Argent, Philippe, Arnau Romeu, Joan, Artamonov, Alexander, Artuso, Marina, Aslanides, Elie, Atzeni, Michele, Auriemma, Giulio, Baalouch, Marouen, Babuschkin, Igor, Bachmann, Sebastian, Back, John, Badalov, Alexey, Baesso, Clarissa, Baker, Sophie, Balagura, Vladislav, Baldini, Wander, Baranov, Alexander, Barlow, Roger, Barschel, Colin, Barsuk, Sergey, Barter, William, Baryshnikov, Fedor, Batozskaya, Varvara, Battista, Vincenzo, Bay, Aurelio, Beaucourt, Leo, Beddow, John, Bedeschi, Franco, Bediaga, Ignacio, Beiter, Andrew, Bel, Lennaert, Beliy, Nikita, Bellee, Violaine, Belloli, Nicoletta, Belous, Konstantin, Belyaev, Ivan, Ben-Haim, Eli, Bencivenni, Giovanni, Benson, Sean, Beranek, Sarah, Berezhnoy, Alexander, Bernet, Roland, Berninghoff, Daniel, Bertholet, Emilie, Bertolin, Alessandro, Betancourt, Christopher, Betti, Federico, Bettler, Marc-Olivier, van Beuzekom, Martinus, Bezshyiko, Iaroslava, Bifani, Simone, Billoir, Pierre, Birnkraut, Alex, Bizzeti, Andrea, Bjørn, Mikkel, Blake, Thomas, Blanc, Frederic, Blusk, Steven, Bocci, Valerio, Boettcher, Thomas, Bondar, Alexander, Bondar, Nikolay, Bordyuzhin, Igor, Borghi, Silvia, Borisyak, Maxim, Borsato, Martino, Bossu, Francesco, Boubdir, Meriem, Bowcock, Themistocles, Bowen, Espen Eie, Bozzi, Concezio, Braun, Svende, Brodzicka, Jolanta, Brundu, Davide, Buchanan, Emma, Burr, Christopher, Bursche, Albert
• Format: Article
• Language: English
• Subjects: High Energy Physics - Experiment; Physics
• ISSN: 1126-6708; 1029-8479
• DOI: 10.1007/JHEP03(2018)182

The difference between the CP asymmetries in the decays Λ$_{c}^{+}$  → pK$^{−}$K$^{+}$ and Λ$_{c}^{+}$  → pπ$^{−}$π$^{+}$ is presented. Proton-proton collision data taken at centre-of-mass energies of 7 and 8 TeV collected by the LHCb detector in 2011 and 2012 are used, corresponding to an integrated luminosity of 3 fb$^{−1}$. The Λ$_{c}^{+}$ candidates are reconstructed as part of the Λ$_{b}^{0}$  → Λ$_{c}^{+}$ μ$^{−}$X decay chain. In order to maximize the cancellation of production and detection asymmetries in the difference, the final-state kinematic distributions of the two samples are aligned by applying phase-space-dependent weights to the Λ$_{c}^{+}$  → pπ$^{−}$π$^{+}$ sample. This alters the definition of the integrated CP asymmetry to A$_{CP}^{wgt}$ (pπ$^{−}$π$^{+}$). Both samples are corrected for reconstruction and selection efficiencies across the five-dimensional Λ$_{c}^{+}$ decay phase space. The difference in CP asymmetries is found to be