Study of the Λ–Λ interaction with femtoscopy correlations in pp and p–Pb collisions at the LHC

• Published in: Physics letters. B Vol. 797
• Main Authors: Acharya, S., Adler, A., Ali, Y., Andreou, D., Antinori, F., Antonioli, P., Bagnasco, S., Barioglio, L., Barnaföldi, G.G., Batyunya, B., Batzing, P.C., Betev, L., Bhatt, H., Bhattacharjee, B., Cheshkov, C., Christensen, C.H., Chujo, T., Cortese, P., Damas, F.P.A., Dash, A., Dönigus, B., Dordic, O., Ehlers, R.J., Eum, J., Faivre, J., Feldkamp, L., Feofilov, G., Fernández Téllez, A., Fronze, G.G., Furget, C., Giubilato, P., Gotovac, S., Grosse-Oetringhaus, J.F., Hamar, G., Harton, A., Herghelegiu, A., Huang, C., Iddon, J.P., Inaba, M., Jadlovsky, J., Jakubowska, M.J., Jones, P.G., Karavicheva, T., Khabanova, Z., Kim, D., Kim, J., Kim, T., Krzewicki, M., Kumar, L., Lapidus, K., Lehner, S., Lim, B., Lisa, M.A., Llope, W.J., Loizides, C., López Torres, E., Malinina, L., Martínez García, G., Mrnjavac, T., Murray, S., Nania, R., Negrao De Oliveira, R.A., Nomokonov, P., Nowakowski, P., Oyama, K., Pan, J., Parmar, S., Passfeld, A., Pezzi, R.P., Planinic, M., Pliquett, F., Pochybova, S., Rami, F., Rath, R., Read, K.F., Roslon, K., Roukoutakis, F., Roy, A., Ryabinkin, E., Ryabov, Y., Sahu, P.K., Schmidt, M.O., Sett, P., Shaikh, W., Sheikh, A.I., Shigaki, K., Stachel, J., Sugitate, T., Suleymanov, M., Tauro, A., Tikhonov, A., Tropp, L., Tumkin, A., Umaka, E.N., van der Kolk, N., Vargyas, M., Vernet, R., Volpe, G., Wilk, G., Zhou, D.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10-10-2019; Elsevier
• Subjects: Fysik; Natural Sciences; Naturvetenskap; Physical Sciences; Subatomic Physics; Subatomär fysik
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2019.134822

This work presents new constraints on the existence and the binding energy of a possible Λ–Λ bound state, the H-dibaryon, derived from Λ–Λ femtoscopic measurements by the ALICE collaboration. The results are obtained from a new measurement using the femtoscopy technique in ▪ collisions at s=13 TeV and p–Pb collisions at sNN=5.02 TeV, combined with previously published results from ▪ collisions at s=7 TeV. The Λ–Λ scattering parameter space, spanned by the inverse scattering length f0−1 and the effective range d0, is constrained by comparing the measured Λ–Λ correlation function with calculations obtained within the Lednický model. The data are compatible with hypernuclei results and lattice computations, both predicting a shallow attractive interaction, and permit to test different theoretical approaches describing the Λ–Λ interaction. The region in the (f0−1,d0) plane which would accommodate a Λ–Λ bound state is substantially restricted compared to previous studies. The binding energy of the possible Λ–Λ bound state is estimated within an effective-range expansion approach and is found to be BΛΛ=3.2−2.4+1.6(stat)−1.0+1.8(syst) MeV.