http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Adare, A.,Aidala, C.,Ajitanand, N. N.,Akiba, Y.,Alfred, M.,Andrieux, V.,Aoki, K.,Apadula, N.,Asano, H.,Ayuso, C.,Azmoun, B.,Babintsev, V.,Bai, M.,Bandara, N. S.,Bannier, B.,Barish, K. N.,Bathe, S.,Baz American Physical Society 2017 Physical Review C Vol.95 No.3
<P>The PHENIX Collaboration has measured the ratio of the yields of psi(2S) to psi(1S) mesons produced in p + p, p + Al, p + Au, and He-3+Au collisions at root S-NN = 200 GeV over the forward and backward rapidity intervals 1.2 < | y | < 2.2. We find that the ratio in p + p collisions is consistent with measurements at other collision energies. In collisions with nuclei, we find that in the forward (p-going or He-3-going) direction, the relative yield of psi(2S) mesons to psi(1S) mesons is consistent with the value measured in p + p collisions. However, in the backward (nucleus-going) direction, the psi(2S) meson is preferentially suppressed by a factor of similar to 2. This suppression is attributed in some models to the breakup of the weakly bound psi(2S) meson through final-state interactions with comoving particles, which have a higher density in the nucleus-going direction. These breakup effects may compete with color screening in a deconfined quark-gluon plasma to produce sequential suppression of excited quarkonia states.</P>
Direct Observation of Sequential Weak Decay of a Double Hypernucleus
AOKI, S.,BAHK, S. Y.,CHUNG, K. S.,CHUNG, S. H.,FUNAHASHI, H.,HAHN, C. H.,HARA, T.,HIRATA, S.,HOSHINO, K.,IEIRI, M.,IIJIMA, T.,IMAI, K.,ISHIGAMI, T.,ITOW, Y.,KAZUNO, M.,KIKUCHI, K.,KIM, C. O.,KIM, D. C 國立昌原大學校 基礎科學硏究所 1992 基礎科學硏究所論文集 Vol.3 No.-
We have studied stars in nuclear emulsion due to the capture at rest of the ??? hyperons produced in the(???) reaction. The sequential weak decay of a double hypernucleus(nucleus with S= -2) has been directly observed. The double hypernucleus is assigned as either ???? or ????. This assignment excludes the existence of the H dibaryon lighter than 2203.7±0.7 MeV/c².
Adare, A.,Afanasiev, S.,Aidala, C.,Ajitanand, N. N.,Akiba, Y.,Akimoto, R.,Al-Bataineh, H.,Alexander, J.,Alfred, M.,Al-Ta'ani, H.,Angerami, A.,Aoki, K.,Apadula, N.,Aphecetche, L.,Aramaki, Y.,Armendariz American Physical Society 2016 Physical review. C Vol.93 No.2
<P>Measurements of the fractional momentum loss (S-loss = delta p(T) / p(T)) of high-transverse-momentum-identified hadrons in heavy-ion collisions are presented. Using pi(0) in Au + Au and Cu + Cu collisions at root s(NN) = 62.4 and 200 GeV measured by the PHENIX experiment at the Relativistic Heavy Ion Collider and and charged hadrons in Pb + Pb collisions measured by the ALICE experiment at the Large Hadron Collider, we studied the scaling properties of S-loss as a function of a number of variables: the number of participants, N-part, the number of quark participants, N-qp, the charged-particle density, dN(ch)/d(eta), and the Bjorken energy density times the equilibration time, epsilon(Bj)tau(0). We find that the p(T), where S-loss has its maximum, varies both with centrality and collision energy. Above the maximum, S-loss tends to follow a power-law function with all four scaling variables. The data at root s(NN) = 200 GeV and 2.76 TeV, for sufficiently high particle densities, have a common scaling of S-loss with dN(ch)/d(eta) and epsilon(Bj)tau(0), lending insight into the physics of parton energy loss.</P>
Search for the H Dibaryon in (K^-,K^+) Reactions
Aoki, S.,Chung, K.S.,Park, I.G.,Song, J. S. 慶尙大學校 기초과학연구소 1990 基礎科學硏究所報 Vol.6 No.-
We have studied (K^-,K^+) reactions from an emulsion target. The S=-2H dibaryon has been searched for by the analysis of the K^+ momentum spectrum together with emulsion data. No evidence of H production was observed in the mass range of 1.90-2.16 GeV/C^2. Upper limits for the production cross section of the H are (0.2-0.6)% of that for the quasifree≡^- production at the 90% confidence level.
PHENIX Collaboration,Afanasiev, S.,Aidala, C.,Ajitanand, N.N.,Akiba, Y.,Alexander, J.,Al-Jamel, A.,Aoki, K.,Aphecetche, L.,Armendariz, R.,Aronson, S.H.,Averbeck, R.,Awes, T.C.,Azmoun, B.,Babintsev, V. North-Holland Pub. Co 2009 Physics letters: B Vol.679 No.4
We present the first measurement of photoproduction of J/ψ and of two-photon production of high-mass e<SUP>+</SUP>e<SUP>-</SUP> pairs in electromagnetic (or ultra-peripheral) nucleus-nucleus interactions, using Au+Au data at s<SUB>NN</SUB>=200 GeV. The events are tagged with forward neutrons emitted following Coulomb excitation of one or both Au<SUP>@</SUP>? nuclei. The event sample consists of 28 events with m<SUB>e<</SUB>SUP><SUB><</SUB>/SUP>+<SUB>e<</SUB>SUP><SUB><</SUB>/SUP>->2 GeV/c<SUP>2</SUP> with zero like-sign background. The measured cross sections at midrapidity of dσ/dy(J/ψ+Xn,y=0)=76+/-33(stat)+/-11(syst) μb and d<SUP>2</SUP>σ/dmdy(e<SUP>+</SUP>e<SUP>-</SUP>+Xn,y=0)=86+/-23(stat)+/-16(syst) μb/(GeV/c<SUP>2</SUP>) for m<SUB>e<</SUB>SUP><SUB><</SUB>/SUP>+<SUB>e<</SUB>SUP><SUB><</SUB>/SUP>-@?[2.0,2.8] GeV/c<SUP>2</SUP> have been compared and found to be consistent with models for photoproduction of J/ψ and QED based calculations of two-photon production of e<SUP>+</SUP>e<SUP>-</SUP> pairs.
Abazov, V.M.,Abbott, B.,Acharya, B.S.,Adams, M.,Adams, T.,Alexeev, G.D.,Alkhazov, G.,Alton, A.,Alverson, G.,Aoki, M.,Askew, A.,Atkins, S.,Augsten, K.,Avila, C.,Badaud, F.,Bagby, L.,Baldin, B.,Bandurin Elsevier 2012 Physics letters: B Vol.714 No.1
<P><B>Abstract</B></P><P>We present measurements of the differential cross section dσ/dpTγ for the inclusive production of a photon in association with a <I>b</I>-quark jet for photons with rapidities |<SUP>yγ</SUP>|<1.0 and 30<pTγ<300?GeV, as well as for photons with 1.5<|<SUP>yγ</SUP>|<2.5 and 30<pTγ<200?GeV, where pTγ is the photon transverse momentum. The <I>b</I>-quark jets are required to have <SUB>pT</SUB>>15 GeV and rapidity |<SUP>yjet</SUP>|<1.5. The results are based on data corresponding to an integrated luminosity of 8.7 fb<SUP>−1</SUP>, recorded with the D0 detector at the Fermilab Tevatron pp¯ Collider at s=1.96?TeV. The measured cross sections are compared with next-to-leading order perturbative QCD calculations using different sets of parton distribution functions as well as to predictions based on the <SUB>kT</SUB>-factorization QCD approach, and those from the <SMALL>SHERPA</SMALL> and <SMALL>PYTHIA</SMALL> Monte Carlo event generators.</P>
Dilepton mass spectra in p+p collisions at s=200 GeV and the contribution from open charm
PHENIX Collaboration,Adare, A.,Afanasiev, S.,Aidala, C.,Ajitanand, N.N.,Akiba, Y.,Al-Bataineh, H.,Alexander, J.,Aoki, K.,Aphecetche, L.,Armendariz, R.,Aronson, S.H.,Asai, J.,Atomssa, E.T.,Averbeck, R. North-Holland Pub. Co 2009 Physics letters: B Vol.670 No.4
<P>PHENIX has measured the electron-positron pair mass spectrum from 0 to 8 GeV/c(2) in p + p collisions at root s = 200 GeV. The contributions from light meson decays to e(+)e(-) pairs have been determined based on measurements of hadron production cross sections by PHENIX. Within the systematic uncertainty of similar to 20% they account for all e(+)e(-) pairs in the mass region below similar to 1 GeV/c(2). The e(+)e(-) pair yield remaining after subtracting these contributions is dominated by semileptonic decays of charmed hadrons correlated through flavor conservation. Using the spectral shape predicted by PYTHIA, we estimate the charm production cross section to be 544 +/- 39(stat) +/- 142(syst) +/- 200(model) pb. which is consistent with QCD calculations and measurements of single leptons by PHENIX. (C) 2008 Elsevier BV. All rights reserved.</P>
Search for pair production of first-generation leptoquarks in pp¯ collisions at s=1.96 TeV
Abazov, V.M.,Abbott, B.,Abolins, M.,Acharya, B.S.,Adams, M.,Adams, T.,Aguilo, E.,Ahsan, M.,Alexeev, G.D.,Alkhazov, G.,Alton, A.,Alverson, G.,Alves, G.A.,Ancu, L.S.,Andeen, T.,Anzelc, M.S.,Aoki, M.,Arn Elsevier 2009 Physics letters: B Vol.681 No.3
<P><B>Abstract</B></P><P>A search for pair production of first-generation leptoquarks (<I>LQ</I>) is performed with data collected by the DØ experiment in pp¯ collisions at s=1.96 TeV at the Fermilab Tevatron Collider. In a sample of data corresponding to ∼1<SUP> fb−1</SUP> the search has been performed on the final states with two electrons and two jets or one electron, two jets and missing transverse energy. We find our data consistent with standard model expectations. The results are combined with those found in a previous analysis of events with two jets and missing transverse energy to obtain scalar <I>LQ</I> mass limits. We set 95% C.L. lower limits on a scalar <I>LQ</I> mass of 299 GeV, 284 GeV and 216 GeV for β=1, β=0.5 and β=0.02 respectively, where <I>β</I> is the <I>LQ</I> branching ratio in the <I>eq</I> channel. This improves the results obtained with a lower luminosity sample from Run II of the Tevatron. Lower limits on vector <I>LQ</I> masses with different couplings from 357 GeV to 464 GeV for β=0.5 are also set using this analysis.</P>
D0 Collaboration,Abazov, V.M.,Abbott, B.,Acharya, B.S.,Adams, M.,Adams, T.,Alexeev, G.D.,Alkhazov, G.,Alton, A.,Alverson, G.,Alves, G.A.,Ancu, L.S.,Aoki, M.,Arnoud, Y.,Arov, M.,Askew, A.,Asman, B.,Atr North-Holland Pub. Co 2011 Physics letters: B Vol.698 No.2
Data recorded by the D0 experiment at the Fermilab Tevatron Collider are analyzed to search for neutral Higgs bosons produced in association with b quarks. The search is performed in the three-b-quark channel using multijet-triggered events corresponding to an integrated luminosity of 5.2 fb<SUP>-1</SUP>. In the absence of any significant excess above background, limits are set on the cross section multiplied by the branching ratio in the Higgs boson mass range 90 to 300 GeV, extending the excluded regions in the parameter space of the minimal supersymmetric standard model.
Abazov, V.M.,Abbott, B.,Abolins, M.,Acharya, B.S.,Adams, M.,Adams, T.,Aguilo, E.,Ahsan, M.,Alexeev, G.D.,Alkhazov, G.,Alton, A.,Alverson, G.,Alves, G.A.,Ancu, L.S.,Andeen, T.,Anzelc, M.S.,Aoki, M.,Arn Elsevier 2009 Physics letters: B Vol.680 No.1
<P><B>Abstract</B></P><P>A search for supersymmetric partners of quarks is performed in the topology of multijet events accompanied by at least one tau lepton decaying hadronically and large missing transverse energy. Approximately 1 fb<SUP>−1</SUP> of pp¯ collision data from the Fermilab Tevatron Collider at a center of mass energy of 1.96 TeV recorded by the DØ detector is analyzed. Results are combined with the previously published DØ inclusive search for squarks and gluinos. No evidence of physics beyond the Standard Model is found and lower limits on the squark mass up to 410 GeV are derived in the framework of minimal supergravity with tanβ=15, <SUB>A0</SUB>=−2<SUB>m0</SUB> and μ<0, in the region where decays to tau leptons dominate. Gaugino masses <SUB>m1/2</SUB> are excluded up to 172 GeV.</P>