Measurement of the time-integrated CP asymmetry in D 0 → K S 0 K S 0 decays

• Published in: The journal of high energy physics 2018-11, Vol.2018 (11), p.1-19
• Main Authors: Adeva, B, P Alvarez Cartelle, Amato, S, Andrews, J E, Aslanides, E, Baldini, W, Bay, A, Belous, K, Bertolin, A, Bursche, A, Calladine, R, K Carvalho Akiba, Chubykin, A, Ciezarek, G, Clarke, P E L, Coco, V, C D’Ambrosio, Dalseno, J, De Bruyn, K, De Miranda, J M, Dordei, F, Dovbnya, A, Durante, P, Dziurda, A, Dzyuba, A, P Fernandez Declara, A Fernandez Prieto, Fleuret, F, J Garra Tico, Gershon, T, Ghez, Ph, Giubega, L, Gotti, C, Yu Guz, Hennessy, K, Henry, L, Hulsbergen, W, Joram, C, Ketel, T, Khurewathanakul, C, Lacarrere, D, Lancierini, D, Lefrançois, J, Likhomanenko, T, Lisovskyi, V, Loi, A, M Lucio Martinez, Lupton, O, Maddrell-Mander, S, Marks, J, Martinelli, M, Merli, A, Mitzel, D S, Mombächer, T, Morello, G, Müller, J, Nasteva, I, Neubert, S, Nieswand, S, D P O’Hanlon, Pais, P R, Patrignani, C, Perazzini, S, Petridis, K, Pinzino, J, Pisani, F, Poluektov, A, Polukhina, N, Price, E, Prouve, C, Quintana, B, Ren, Z, A Romero Vidal, B Sanmartin Sedes, Santacesaria, R, Sarti, A, Satta, A, Schael, S, Stagni, F, Sun, J, Sun, L, Tonelli, D, Tran, M T, Tsaregorodtsev, A, Ustyuzhanin, A, Vacca, C, Valenti, G, P Vazquez Regueiro, M van Veghel, Verlage, T A, Vieira, D, Voneki, B, Vorobyev, V, de Vries, J A, Wicht, J, Williams, M, Witek, M, Zavertyaev, M, Zhukov, V, Zonneveld, J B
• Format: Article
• Language: English
• Subjects: Asymmetry; Charm physics; CP violation; Decay; Flavor physics; Hadron-Hadron scattering (experiments); High energy physics; Luminosity; Time measurement
• ISSN: 1029-8479
• DOI: 10.1007/JHEP11(2018)048

A measurement of the time-integrated CP asymmetry in D0 → KS0KS0 decays is reported. The data correspond to an integrated luminosity of about 2 fb−1 collected in 2015–2016 by the LHCb collaboration in pp collisions at a centre-of-mass energy of 13 TeV. The D0 candidate is required to originate from a D*+ → D0π+ decay, allowing the determination of the flavour of the D0 meson using the pion charge. The D0 → K+K− decay, which has a well measured CP asymmetry, is used as a calibration channel. The CP asymmetryfor D0 → KS0KS0 is measured to beACPD0→KS0KS0=4.3±3.4±1.0%,\[ {\mathcal{A}}^{CP}\left({D}^0\to {K}_S^0{K}_S^0\right)=\left(4.3\pm 3.4\pm 1.0\right)\%, \]where the first uncertainty is statistical and the second is systematic. This result is combined with the previous LHCb measurement at lower centre-of-mass energies to obtainACPD0→KS0KS0=2.3±2.8±0.9%.\[ {\mathcal{A}}^{CP}\left({D}^0\to {K}_S^0{K}_S^0\right)=\left(2.3\pm 2.8\pm 0.9\right)\%. \]