Results on ϕ meson production in inelastic p+p collisions at CERN SPS energies are presented. They are derived from data collected by the NA61/SHINE fixed target experiment, by means of invariant ...mass spectra fits in the ϕ→K+K- decay channel. They include the first ever measured double differential spectra of ϕ mesons as a function of rapidity y and transverse momentum pT for proton beam momenta of 80GeV/c and 158GeV/c, as well as single differential spectra of y or pT for beam momentum of 40GeV/c. The corresponding total ϕ yields per inelastic p+p event are obtained. These results are compared with existing data on ϕ meson production in p+p collisions. The comparison shows consistency but superior accuracy of the present measurements. The emission of ϕ mesons in p+p reactions is confronted with that occurring in Pb+Pb collisions, and the experimental results are compared with model predictions. It appears that none of the considered models can properly describe all the experimental observations.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract The measurement of $$K^{*}(892)^0$$ K∗(892)0 resonance production via its $$K^{+}\pi ^{-}$$ K+π- decay mode in inelastic p+p collisions at beam momentum 158 $$\text{ Ge }\text{ V }\!/\!c$$ ...GeV/c ($$\sqrt{s_{NN}}=17.3$$ sNN=17.3 $$\text{ Ge }\text{ V }$$ GeV ) is presented. The data were recorded by the NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The template method was used to extract the $$K^{*}(892)^0$$ K∗(892)0 signal and double-differential transverse momentum and rapidity spectra were obtained. The full phase-space mean multiplicity of $$K^{*}(892)^0$$ K∗(892)0 mesons was found to be $$(78.44 \pm 0.38 \mathrm {(stat)} \pm 6.0 \mathrm {(sys)) \cdot 10^{-3}}$$ (78.44±0.38(stat)±6.0(sys))·10-3 . The NA61/SHINEresults are compared with the Epos1.99 and Hadron Resonance Gas models as well as with world data from p+p and nucleus–nucleus collisions.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Results on $$\phi $$ ϕ meson production in inelastic $$p + p$$ p+p collisions at CERN SPS energies are presented. They are derived from data collected by the NA61/SHINE fixed target ...experiment, by means of invariant mass spectra fits in the $$\phi \rightarrow K^+ K^- $$ ϕ→K+K- decay channel. They include the first ever measured double differential spectra of $$\phi $$ ϕ mesons as a function of rapidity $$y$$ y and transverse momentum $$p_{\text {T}}$$ pT for proton beam momenta of $$80 \, \hbox {GeV}/c$$ 80GeV/c and $$158 \, \hbox {GeV}/c$$ 158GeV/c , as well as single differential spectra of $$y$$ y or $$p_{\text {T}}$$ pT for beam momentum of $$40 \, \hbox {GeV}/c$$ 40GeV/c . The corresponding total $$\phi $$ ϕ yields per inelastic $$p + p$$ p+p event are obtained. These results are compared with existing data on $$\phi $$ ϕ meson production in $$p + p$$ p+p collisions. The comparison shows consistency but superior accuracy of the present measurements. The emission of $$\phi $$ ϕ mesons in $$p + p$$ p+p reactions is confronted with that occurring in $$\mathrm{Pb} + \mathrm{Pb}$$ Pb+Pb collisions, and the experimental results are compared with model predictions. It appears that none of the considered models can properly describe all the experimental observations.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
An algorithm is presented for track reconstruction in the large angle spectrometer of a high energy fixed target experiment. Pattern recognition is provided by the association of segments found on ...both sides of the deflecting magnet within a variable roadwidth tuned to the characteristics of the experimental layout. Curved tracks swept away by the magnet are also searched for in the upstream telescope. The procedure has been tested on various sets of simulated data from the COMPASS experiment at CERN. The obtained track reconstruction efficiency reaches 85% for momenta above
2.5
GeV
and is about 50% at
1
GeV
, fulfilling one of the basic requirements of this experiment for the analysis of charmed meson decays.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Measurements of the Formula omitted, Formula omitted, and proton double differential yields emitted from the surface of the 90- Formula omitted-long carbon target (T2K replica) were performed for the ...incoming Formula omitted Formula omitted protons with the NA61/SHINE spectrometer at the CERN SPS using data collected during 2010 run. The double differential Formula omitted yields were measured with increased precision compared to the previously published NA61/SHINE results, while the Formula omitted and proton yields were obtained for the first time. A strategy for dealing with the dependence of the results on the incoming proton beam profile is proposed. The purpose of these measurements is to reduce significantly the (anti)neutrino flux uncertainty in the T2K long-baseline neutrino experiment by constraining the production of (anti)neutrino ancestors coming from the T2K target.
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Abstract Measurements of the $$\pi ^\pm $$ π± , $$K^\pm $$ K± , and proton double differential yields emitted from the surface of the 90-$$\hbox {cm}$$ cm -long carbon target (T2K replica) were ...performed for the incoming $$31\,$$ 31 $$\hbox {GeV}\!/\!c$$ GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS using data collected during 2010 run. The double differential $$\pi ^\pm $$ π± yields were measured with increased precision compared to the previously published NA61/SHINE results, while the $$K^\pm $$ K± and proton yields were obtained for the first time. A strategy for dealing with the dependence of the results on the incoming proton beam profile is proposed. The purpose of these measurements is to reduce significantly the (anti)neutrino flux uncertainty in the T2K long-baseline neutrino experiment by constraining the production of (anti)neutrino ancestors coming from the T2K target.
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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.
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Abstract This paper reports measurements of two-pion femtoscopic correlations in Be+Be collisions at a beam momentum of 150 $$A\,\hbox {GeV}\!/\!c$$ A GeV / c (energy available in the center-of-mass ...system for nucleon pair $$\sqrt{s_{\text {NN}}} = 16.84$$ 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 $$\alpha $$ α is approximately constant as a function of $$m_{\text {T}}$$ m T , and far from both the Gaussian case of $$\alpha = 2$$ α = 2 or the conjectured value at the critical endpoint, $$\alpha = 0.5$$ α = 0.5 . The radius scale parameter R shows a slight decrease in $$m_{\text {T}}$$ m T , which can be explained as a signature of transverse flow. Finally, an approximately constant trend of the intercept parameter $$\lambda $$ λ as a function of $$m_{\text {T}}$$ m T was observed, similar to previous NA44 S + Pb results (obtained with a Gaussian approximation, but unlike RHIC results).
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This document reports on a series of experimental and theoretical studies conducted to assess the astro-particle physics potential of three future large-scale particle detectors proposed in Europe as ...next generation underground observatories. The proposed apparatus employ three different and, to some extent, complementary detection techniques: GLACIER (liquid Argon TPC), LENA (liquid scintillator) and MEMPHYS (\WC), based on the use of large mass of liquids as active detection media. The results of these studies are presented along with a critical discussion of the performance attainable by the three proposed approaches coupled to existing or planned underground laboratories, in relation to open and outstanding physics issues such as the search for matter instability, the detection of astrophysical- and geo-neutrinos and to the possible use of these detectors in future high-intensity neutrino beams.
Measurements of inclusive spectra and mean multiplicities of π±, K±, p and p¯ produced in inelastic p + p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c (s= 6.3, 7.7, ...8.8, 12.3 and 17.3 GeV, respectively) were performed at the CERN Super Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer. Spectra are presented as function of rapidity and transverse momentum and are compared to predictions of current models. The measurements serve as the baseline in the NA61/SHINE study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter.
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