This paper presents the energy dependence of multiplicity and net-electric charge fluctuations in p+p interactions at beam momenta 20, 31, 40, 80, and 158 Ge V /c . Results are corrected for the experimental biases and quantified with the use of cumulants and factorial cumulants. Cumulant ratios are an essential tool in the search for the critical point of strongly interacting matter in heavy ion collisions. Measurements performed in p+p interactions provide a vital baseline estimation in these studies. The measured signals are compared with the string hadronic models Epos1.99 and FTFP-BERT.

Measurements of K_S^0 meson production via its π^+π^- decay mode in inelastic p+p interactions at incident projectile momenta of 31, 40 and 80 GeV/c (√(s_NN)=7.7, 8.8 and 12.3 GeV, respectively) are presented. The data were recorded by the NA61/SHINE spectrometer at the CERN Super Proton Synchrotron. Double-differential distributions were obtained in transverse momentum and rapidity. The mean multiplicities of K_S^0 mesons were determined to be (5.95 ± 0.19 (stat) ± 0.22 (sys)) × 10^-2 at 31 GeV/c, (7.61 ± 0.13 (stat) ± 0.31 (sys)) × 10^-2 at 40 GeV/c and (11.58 ± 0.12 (stat) ± 0.37 (sys)) × 10^-2 at 80 GeV/c. The results on K^0_S production are compared with model calculations (Epos1.99, SMASH 2.0 and PHSD) as well as with published data from other experiments.

Abstract The yields of $$K^0_S$$ K S 0 mesons have been measured in inelastic p+p interactions at incident projectile momenta of 31, 40 and 80 $$\text {Ge}\hspace{-1.00006pt}\text {V}\!/\!c$$ Ge V / c ( $$\sqrt{s_{NN}}=7.7, 8.8$$ s NN = 7.7 , 8.8 and 12.3 $$\text {Ge}\hspace{-1.00006pt}\text {V}$$ Ge V , respectively). The data were recorded by the NA61 $$/$$ / SHINE spectrometer at the CERN Super Proton Synchrotron and the $$K^0_S$$ K S 0 mesons identified via their decays into $$\pi ^{+} \pi ^{-}$$ π + π - pairs. Double-differential distributions are presented as function of transverse momentum and rapidity. The mean multiplicities of $$K^0_S$$ K S 0 mesons were determined to be $$(5.95 \pm 0.19 (stat) \pm 0.30 (sys)) \times 10^{-2}$$ ( 5.95 ± 0.19 ( s t a t ) ± 0.30 ( s y s ) ) × 10 - 2 at 31 $$\text {Ge}\hspace{-1.00006pt}\text {V}\!/\!c$$ Ge V / c , $$(7.61 \pm 0.13 (stat) \pm 0.43 (sys)) \times 10^{-2}$$ ( 7.61 ± 0.13 ( s t a t ) ± 0.43 ( s y s ) ) × 10 - 2 at 40 $$\text {Ge}\hspace{-1.00006pt}\text {V}\!/\!c$$ Ge V / c and $$(11.58 \pm 0.12 (stat) \pm 0.55 (sys)) \times 10^{-2}$$ ( 11.58 ± 0.12 ( s t a t ) ± 0.55 ( s y s ) ) × 10 - 2 at 80 $$\text {Ge}\hspace{-1.00006pt}\text {V}\!/\!c$$ Ge V / c . The results on $$K^{0}_{S}$$ K S 0 production are compared with the production of charged kaons in corresponding reactions and with model calculations (Epos1.99, SMASH 2.0 and PHSD) as well as with published data from other experiments.

The NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of π ^± , K^± , p and p̅ produced in ^40Ar+^45Sc collisions at beam momenta of 13A, 19A, 30A, 40A, 75A and 150A Ge V /c . The analysis uses the 10 K^± / π ^± ratios as well as of inverse slope parameters of the K^± transverse mass distributions are placed in between those found in inelastic p+p and central Pb + Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical or dynamical models.

The yields of K^0_S mesons have been measured in inelastic p+p interactions at incident projectile momenta of 31, 40 and 80 GeV/c ( √(s_NN)=7.7, 8.8 and 12.3 GeV , respectively). The data were recorded by the NA61 / SHINE spectrometer at the CERN Super Proton Synchrotron and the K^0_S mesons identified via their decays into π ^+π ^- pairs. Double-differential distributions are presented as function of transverse momentum and rapidity. The mean multiplicities of K^0_S mesons were determined to be (5.95 ± 0.19 (stat) ± 0.30 (sys)) × 10^-2 at 31 GeV/c , (7.61 ± 0.13 (stat) ± 0.43 (sys)) × 10^-2 at 40 GeV/c and (11.58 ± 0.12 (stat) ± 0.55 (sys)) × 10^-2 at 80 GeV/c . The results on K^0_S production are compared with the production of charged kaons in corresponding reactions and with model calculations (Epos1.99, SMASH 2.0 and PHSD) as well as with published data from other experiments.

Abstract The critical point of strongly interacting matter is searched for at the CERN SPS by the NA61/SHINE experiment in central $$^{40}$$ 40 Ar + $$^{45}$$ 45 Sc collisions at 13 A, 19 A, 30 A, 40 A, and 75 A GeV/c. The dependence of the second-order scaled factorial moments of proton multiplicity distributions on the number of subdivisions in transverse momentum space is measured. The intermittency analysis uses statistically independent data sets for every subdivision in transverse and cumulative-transverse momentum variables. The results obtained do not indicate the searched intermittent pattern. An upper limit on the fraction of correlated protons and the intermittency index is obtained based on a comparison with the Power-law Model.

AbstractThe NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of $$\pi ^\pm $$ π ± , $$K^\pm $$ K ± , p and $$\bar{p}$$ p ¯ produced in $$^{40}\hbox {Ar+}^{45}\hbox {Sc}$$ 40 Ar+ 45 Sc collisions at beam momenta of 13A, 19A, 30A, 40A, 75A and 150A $$\text{ Ge }\hspace{-1.00006pt}\text{ V }\!/\!c$$ Ge V / c . The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. The energy dependence of the $$K^\pm $$ K ± /$$\pi ^\pm $$ π ± ratios as well as of inverse slope parameters of the $$K^\pm $$ K ± transverse mass distributions are placed in between those found in inelastic $$p+p$$ p + p and central Pb + Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical or dynamical models.

The critical point of strongly interacting matter is searched for at the CERN SPS by the NA61/SHINE experiment in central $^{40}$Ar +$^{45}$Sc collisions at 13$A$, 19$A$, 30$A$, 40$A$, and 75$A$ GeV/$c$. The dependence of the second-order scaled factorial moments of proton multiplicity distributions on the number of subdivisions in transverse momentum space is measured. The intermittency analysis uses statistically independent data sets for every subdivision in transverse and cumulative-transverse momentum variables. The results obtained do not indicate the searched intermittent pattern. An upper limit on the fraction of correlated protons and the intermittency index is obtained based on a comparison with the Power-law Model.

Abstract The NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of $$\pi ^\pm $$ π ± , $$K^\pm $$ K ± , p and $$\bar{p}$$ p ¯ produced in $$^{40}\hbox {Ar+}^{45}\hbox {Sc}$$ 40 Ar+ 45 Sc collisions at beam momenta of 13A, 19A, 30A, 40A, 75A and 150A $$\text{ Ge }\hspace{-1.00006pt}\text{ V }\!/\!c$$ Ge V / c . The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. The energy dependence of the $$K^\pm $$ K ± / $$\pi ^\pm $$ π ± ratios as well as of inverse slope parameters of the $$K^\pm $$ K ± transverse mass distributions are placed in between those found in inelastic $$p+p$$ p + p and central Pb + Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical or dynamical models.

The critical point of strongly interacting matter is searched for at the CERN SPS by the NA61/SHINE experiment in central Ar-40 +Sc-45 collisions at 13A, 19A, 30A, 40A, and 75A GeV/c. The dependence of the second-order scaled factorial moments of proton multiplicity distributions on the number of subdivisions in transverse momentum space is measured. The intermittency analysis uses statistically independent data sets for every subdivision in transverse and cumulative-transverse momentum variables. The results obtained do not indicate the searched intermittent pattern. An upper limit on the fraction of correlated protons and the intermittency index is obtained based on a comparison with the Power-law Model

AbstractThe yields of $$K^0_S$$ K S 0 mesons have been measured in inelastic p+p interactions at incident projectile momenta of 31, 40 and 80 $$\text {Ge}\hspace{-1.00006pt}\text {V}\!/\!c$$ Ge V / c ($$\sqrt{s_{NN}}=7.7, 8.8$$ s NN = 7.7 , 8.8 and 12.3 $$\text {Ge}\hspace{-1.00006pt}\text {V}$$ Ge V , respectively). The data were recorded by the NA61$$/$$ / SHINE spectrometer at the CERN Super Proton Synchrotron and the $$K^0_S$$ K S 0 mesons identified via their decays into $$\pi ^{+} \pi ^{-}$$ π + π - pairs. Double-differential distributions are presented as function of transverse momentum and rapidity. The mean multiplicities of $$K^0_S$$ K S 0 mesons were determined to be $$(5.95 \pm 0.19 (stat) \pm 0.30 (sys)) \times 10^{-2}$$ ( 5.95 ± 0.19 ( s t a t ) ± 0.30 ( s y s ) ) × 10 - 2 at 31 $$\text {Ge}\hspace{-1.00006pt}\text {V}\!/\!c$$ Ge V / c , $$(7.61 \pm 0.13 (stat) \pm 0.43 (sys)) \times 10^{-2}$$ ( 7.61 ± 0.13 ( s t a t ) ± 0.43 ( s y s ) ) × 10 - 2 at 40 $$\text {Ge}\hspace{-1.00006pt}\text {V}\!/\!c$$ Ge V / c and $$(11.58 \pm 0.12 (stat) \pm 0.55 (sys)) \times 10^{-2}$$ ( 11.58 ± 0.12 ( s t a t ) ± 0.55 ( s y s ) ) × 10 - 2 at 80 $$\text {Ge}\hspace{-1.00006pt}\text {V}\!/\!c$$ Ge V / c . The results on $$K^{0}_{S}$$ K S 0 production are compared with the production of charged kaons in corresponding reactions and with model calculations (Epos1.99, SMASH 2.0 and PHSD) as well as with published data from other experiments.

The NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. 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 $^{40}$Ar+$^{45}$Sc collisions at beam momenta of 13$A$, 19$A$, 30$A$, 40$A$, 75$A$ and 150$A$ GeV/$c$. The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. 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 placed in between those found in inelastic $p$+$p$ and central Pb+Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical (SMES, HRG) or dynamical (EPOS, UrQMD, PHSD, SMASH) models.

The critical point of dense, strongly interacting matter is searched for at the CERN SPS in 40Ar + 45Sc collisions at 150A Ge V /c. The dependence of second-order scaled factorial moments of proton multiplicity distribution on the number of subdivisions of transverse momentum space is measured. The intermittency analysis is performed using both transverse momentum and cumulative transverse momentum. For the first time, statistically independent data sets are used for each subdivision number. The obtained results do not indicate any statistically significant intermittency pattern. An upper limit on the fraction of correlated proton pairs and the power of the correlation function is obtained based on a comparison with the Power-law Model developed for this purpose.

We present a measurement of the momentum spectra of ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${\mathrm{K}}^{\ifmmode\pm\else\textpm\fi{}}$, ${\mathrm{p}}^{\ifmmode\pm\else\textpm\fi{}}$, $\mathrm{\ensuremath{\Lambda}}$, $\overline{\mathrm{\ensuremath{\Lambda}}}$, and ${\mathrm{K}}_{\mathrm{S}}^{0}$ produced in interactions of negatively charged pions with carbon nuclei at beam momenta of 158 and $350\text{ }\text{ }\mathrm{GeV}/c$. The total production cross sections are measured as well. The data were collected with the large-acceptance spectrometer of the fixed target experiment NA61/SHINE at the CERN SPS. The obtained double-differential $p\text{\ensuremath{-}}{p}_{\mathrm{T}}$ spectra provide a unique reference dataset with unprecedented precision and large phase-space coverage to tune models used for the simulation of particle production in extensive air showers in which pions are the most numerous projectiles.

This paper presents multiplicity measurements of K0S, A, and A over bar produced in 120 GeV=c proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment during two different periods. Decays of these neutral hadrons impact the measured x+, x-, p and p over bar multiplicities in the 120 GeV=c proton-carbon reaction, which are crucial inputs for long-baseline neutrino experiment predictions of neutrino beam flux. The double-differential multiplicities presented here will be used to more precisely measure charged-hadron multiplicities in this reaction, and to reweight neutral hadron production in neutrino beam Monte Carlo simulations.

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 ^± , K^± , p and p̅ produced in the 20

This paper reports measurements of two-pion femtoscopic correlations in Be+Be collisions at a beam momentum of 150 A GeV/c (energy available in the center-of-mass system for nucleon pair √(s_NN) = 16.84 GeV) by the NA61/SHINE experiment at the CERN SPS accelerator. The obtained momentum space correlation functions can be well described by a Lévy distributed source model. The transverse mass dependence of the Lévy source parameters is presented, and their possible theoretical interpretations are discussed. The results show that the Lévy exponent α is approximately constant as a function of m_T , and far from both the Gaussian case of α = 2 or the conjectured value at the critical endpoint, α = 0.5 . The radius scale parameter R shows a slight decrease in m_T , which can be explained as a signature of transverse flow. Finally, an approximately constant trend of the intercept parameter λ as a function of m_T was observed, similar to previous NA44 S + Pb results (obtained with a Gaussian approximation, but unlike RHIC results).

We present a measurement of the momentum spectra of $\pi^\pm$, K$^\pm$, p$^\pm$, $\Lambda$, $\bar{\Lambda}$ and K$^{0}_{S}$ produced in interactions of negatively charged pions with carbon nuclei at beam momenta of 158 and 350 GeV/c. The total production cross sections are measured as well. The data were collected with the large-acceptance spectrometer of the fixed target experiment NA61/SHINE at the CERN SPS. The obtained double-differential $p$-$p_T$ spectra provide a unique reference data set with unprecedented precision and large phase-space coverage to tune models used for the simulation of particle production in extensive air showers in which pions are the most numerous projectiles.