Open charm measurements in NA61/SHINE at CERN SPS

The measurements of open charm production was proposed as an important tool to investigate the properties of the hot and dense matter formed in nucleus-nucleus collisions as well as to provide the means for model independent interpretation of the existing data on J/ψ suppression. Recently, the experimental setup of the NA61/SHINE experiment was supplemented with a Vertex Detector which was motivated by the importance and the possibility of the first direct measurements of open charm meson production in heavy ion collisions at SPS energies. First test data taken in December 2016 on Pb+Pb collisions at 150A GeV/c allowed to validate the general concept of D0 meson detection via its D0 → π+ + K− decay channel and delivered a first indication of open charm production. The physics motivation of open charm measurements at SPS energies, pilot results on open charm production, and finally, the future plans of open charm measurements in the NA61/SHINE experiment after LS2 are presented

Measurements of π±\pi ^\pm , K±K^\pm , p and pˉ\bar{p} spectra in 7^7Be+9^9Be collisions at beam momenta from 19A to 150A GeV ⁣/ ⁣c{\mathrm{Ge} \mathrm{V}}\!/\!c with the NA61/SHINE spectrometer at the CERN SPS

The NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) studies the onset of deconfinement in hadron matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of π ± π± , K ± K± , p and p ¯ p¯ produced in the 20% most central 7 7 Be+ 9 9 Be collisions at beam momenta of 19A, 30A, 40A, 75A and 150A GeV/c GeV/c . The energy dependence of the K ± K± /π ± π± ratios as well as of inverse slope parameters of the K ± K± transverse mass distributions are close to those found in inelastic p+p reactions. The new results are compared to the world data on p+p and Pb+Pb collisions as well as to predictions of the Epos, Urqmd, Ampt, Phsd and Smash models

Proton-proton interactions and onset of deconfinement

The experiment of the NA61/SHINE Collaboration at the CERN SPS is performing a unique study of the phase diagram of strongly interacting matter by varying collision energy and nuclear mass number of colliding nuclei. In central Pb+Pb collisions, the experiment of the NA49 Collaboration found structures in the energy dependence of several observables in the energy range of the CERN SPS that had been predicted for the transition to a deconfined phase. New measurements of the NA61/SHINE Collaboration find intriguing similarities in p+p interactions for which no deconfinement transition is expected at the energies of the SPS. Possible implications will be discussed

Measurements of hadron production in π⁺ + C and π⁺ + Be interactions at 60 GeV/c

Precise knowledge of hadron production rates in the generation of neutrino beams is necessary for accelerator-based neutrino experiments to achieve their physics goals. NA61/SHINE, a large-acceptance hadron spectrometer, has recorded hadron + nucleus interactions relevant to ongoing and future longbaseline neutrino experiments at Fermi National Accelerator Laboratory. This paper presents three analyses of interactions of 60 GeV/c π⁺ with thin, fixed carbon and beryllium targets. Integrated production and inelastic cross sections were measured for both of these reactions. In an analysis of strange, neutral hadron production, differential production multiplicities of K0/S, Λ and Λ̄ were measured. Lastly, in an analysis of charged hadron production, differential production multiplicities of π⁺, π⁻, K⁺, K⁻ and protons were measured. These measurements will enable long-baseline neutrino experiments to better constrain predictions of their neutrino flux in order to achieve better precision on their neutrino cross section and oscillation measurements

Measurements of π±\pi ^\pm , K±K^\pm , p and pˉ\bar{p} spectra in 7^7Be+9^9Be collisions at beam momenta from 19A to 150A GeV ⁣/ ⁣c{\mathrm{Ge} \mathrm{V}}\!/\!c with the NA61/SHINE spectrometer at the CERN SPS

The NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) studies the onset of deconfinement in hadron matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of π ± π± , K ± K± , p and p ¯ p¯ produced in the 20% most central 7 7 Be+ 9 9 Be collisions at beam momenta of 19A, 30A, 40A, 75A and 150A GeV/c GeV/c . The energy dependence of the K ± K± /π ± π± ratios as well as of inverse slope parameters of the K ± K± transverse mass distributions are close to those found in inelastic p+p reactions. The new results are compared to the world data on p+p and Pb+Pb collisions as well as to predictions of the Epos, Urqmd, Ampt, Phsd and Smash models

Hidden strangeness shines in NA61/SHINE

Preliminary results on the ϕ (1020) meson production in inelastic proton-proton collisions measured by the NA61/SHINE experiment at the CERN SPS are presented in these proceedings. The results include the first ever differential pT and y measurements at beam momenta of 40 and 80 GeV and the most ever detailed experimental data at 158GeV. The comparison of p + p to Pb + Pb results shows a non-trivial system size dependence of the widths of the rapidity distributions for ϕ mesons, contrasting with that of other hadrons. The results are furthermore compared to the world data on ϕ meson production, demonstrating the better accuracy achieved by the NA61/SHINE experiment, and to several models. None of the models is found to be able to describe simultaneously the shape of transverse momentum spectra, the shape of rapidity distribution and the total yield

Measurements of π−\pi ^- production in 7^7Be + 9^9Be collisions at beam momenta from 19A to 150A GeV ⁣/ ⁣cA\,\text{ GeV }\!/\!c in the NA61/SHINE experiment at the CERN SPS

The NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) studies the onset of deconfinement in hadron matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of $\pi ^\pm$, $K^\pm$, p and $\bar{p}$ produced in the 20% most central$^7$Be+$^9$Be collisions at beam momenta of 19A, 30A, 40A, 75A and 150A ${\mathrm{Ge} \mathrm{V}}\!/\!c$. The energy dependence of the $K^\pm$/$\pi ^\pm$ ratios as well as of inverse slope parameters of the $K^\pm$ transverse mass distributions are close to those found in inelastic p+p reactions. The new results are compared to the world data on p+p and Pb+Pb collisions as well as to predictions of the Epos, Urqmd, Ampt, Phsd and Smash models

Search for the critical point by the NA61/SHINE experiment

NA61/SHINE is a fixed target experiment operating at CERN SPS. Its main goals are to search for the critical point of stronglyinteractingmatterandtostudytheonsetofdeconfinement. Forthesegoalsascanofthetwodimensionalphase diagram (T-μB) is being performed at the SPS by measurements of hadron production in proton-proton, proton-nucleus and nucleus-nucleus interactions as a function of collision energy. In this paper the status of the search for the critical point of strongly interacting matter by the NA61/SHINE Collaboration is presented including recent results on proton intermittency, strongly intensive fluctuation observables of multiplicity and transverse momentum fluctuations. These measurements are expected to be sensitive to the correlation length and, therefore, have the ability to reveal the existence of the critical point via possible non-monotonic behavior. The new NA61/SHINE results are compared to the model predictions