作者：
Adam, J.*;Adamczyk, L.;Adams, J. R.;Adkins, J. K.;Agakishiev, G.;...
期刊：
PHYSICAL REVIEW C,2018年98(1) ISSN：2469-9985
通讯作者：
Adam, J.
作者机构：
[Adam, J.; Cherney, M.; Seger, J.] Creighton Univ, Omaha, NE 68178 USA.;[Sikora, R.; Fulek, L.; Przybycien, M.; Adamczyk, L.] AGH Univ Sci & Technol, FPACS, PL-30059 Krakow, Poland.;[Underwood, D. G.; Krueger, K.; Spinka, H. M.] Argonne Natl Lab, Argonne, IL 60439 USA.;[Ullrich, T.; Smirnov, D.; Chang, Z.; Todoroki, T.; Jia, J.; Ljubicic, T.; Fazio, S.; Xu, Z.; Ma, R.; Ogawa, A.; Ke, H. W.; Page, B. S.; Ruan, L.; Tang, A. H.; Videbaek, F.; Fisyak, Y.; Lauret, J.; Tribedy, P.; Bland, L. C.; Yang, S.; Aschenauer, E. C.; Longacre, R. S.; Webb, J. C.; Sorensen, P.; Christie, W.; Arkhipkin, D.; Lebedev, A.; Eyser, O.; Dunlop, J. C.; Landgraf, J. M.; Pak, R.; Yip, K.; Schmidke, W. B.; Chakaberia, I; Didenko, L.; Guryn, W.; Van Buren, G.; Lee, J. H.] Brookhaven Natl Lab, Upton, NY 11973 USA.;[Perkins, C.; Crawford, H. J.; Engelage, J.; Nelson, J. M.; Judd, E. G.] Univ Calif Berkeley, Berkeley, CA 94720 USA.
通讯机构：
[Adam, J.] C;Creighton Univ, Omaha, NE 68178 USA.
摘要：
Global polarization of Lambda hyperons has been measured to be of the order of a few tenths of a percentage in Au+Au collisions at root s(NN) = 200 GeV, with no significant difference between Lambda and (Lambda) over bar. These new results reveal the collision energy dependence of the global polarization together with the results previously observed at root s(NN) = 7.7-62.4 GeV and indicate noticeable vorticity of the medium created in noncentral heavy-ion collisions at the highest Relativistic Heavy Ion Collider collision energy. The signal is in rough quantitative agreement with the theoretical predictions from a hydrodynamic model and from a multi-phase transport model. The polarization is larger in more peripheral collisions, and depends weakly on the hyperon's transverse momentum and pseudorapidity eta(H) within vertical bar eta(H)vertical bar < 1. An indication of the polarization dependence on the event-by-event charge asymmetry is observed at the 2 sigma level, suggesting a possible contribution to the polarization from the axial current induced by the initial magnetic field.
作者机构：
[Bazavov, A.] Michigan State Univ, Dept Computat Math Sci & Engn, E Lansing, MI 48824 USA.;[Bazavov, A.] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA.;[Ding, H. -T.; Kaczmarek, O.] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Ding, H. -T.; Kaczmarek, O.] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Hegde, P.] Indian Inst Sci, Ctr High Energy Phys, Bangalore 560012, Karnataka, India.
通讯机构：
[Hegde, P.] I;Indian Inst Sci, Ctr High Energy Phys, Bangalore 560012, Karnataka, India.
摘要：
We calculated the QCD equation of state using Taylor expansions that include contributions from up to sixth order in the baryon, strangeness and electric charge chemical potentials. Calculations have been performed with the Highly Improved Staggered Quark action in the temperature range T∈[135 MeV,330 MeV] using up to four different sets of lattice cutoffs corresponding to lattices of size Nσ3×Nτ with aspect ratio Nσ/Nτ=4 and Nτ=6−16. The strange quark mass is tuned to its physical value, and we use two strange to light quark mass ratios ms/ml=20 and 27, which in the continuum limit correspond to a pion mass of about 160 and 140 MeV, respectively. Sixth-order results for Taylor expansion coefficients are used to estimate truncation errors of the fourth-order expansion. We show that truncation errors are small for baryon chemical potentials less then twice the temperature ( μB≤2T). The fourth-order equation of state thus is suitable for the modeling of dense matter created in heavy ion collisions with center-of-mass energies down to sNN∼12 GeV. We provide a parametrization of basic thermodynamic quantities that can be readily used in hydrodynamic simulation codes. The results on up to sixth-order expansion coefficients of bulk thermodynamics are used for the calculation of lines of constant pressure, energy and entropy densities in the T−μB plane and are compared with the crossover line for the QCD chiral transition as well as with experimental results on freeze-out parameters in heavy ion collisions. These coefficients also provide estimates for the location of a possible critical point. We argue that results on sixth-order expansion coefficients disfavor the existence of a critical point in the QCD phase diagram for μB/T≤2 and T/Tc(μB=0)>0.9.
摘要：
We present measurements of bulk properties of the matter produced in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 11.5, 19.6, 27, and 39 GeV using identified hadrons ($\pi^\pm$, $K^\pm$, $p$ and $\bar{p}$) from the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity ($|y|<$0.1) results for multiplicity densities $dN/dy$, average transverse momenta $\langle p_T \rangle$ and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.
作者机构：
[Luo, Xiaofeng; Xu, Nu] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;[Luo, Xiaofeng; Xu, Nu] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;[Luo, Xiaofeng] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.;[Xu, Nu] Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA.
通讯机构：
[Luo, Xiaofeng] C;[Luo, Xiaofeng] U;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.;Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
关键词：
QCD critical point;Fluctuations and correlations;Relativistic heavy-ion collisions;Conserved charges
摘要：
Fluctuations of conserved quantities, such as baryon, electric charge, and strangeness number, are sensitive observables in relativistic heavy-ion collisions to probe the QCD phase transition and search for the QCD critical point. In this paper, we review the experimental measurements of the cumulants (up to fourth order) of event-byevent net-proton (proxy for net-baryon), net-charge and netkaon (proxy for net-strangeness) multiplicity distributions in Au+Au collisions at sNN~(1/2) = 7.7,11.5,14.5,19.6, 27, 39, 62.4, 200 GeV from the first phase of beam energy scan program at the relativistic heavy-ion collider (RHIC). We also summarize the data analysis methods of suppressing the volume fluctuations, auto-correlations, and the unified description of efficiency correction and error estimation. Based on theoretical and model calculations, we will discuss the characteristic signatures of critical point as well as backgrounds for the fluctuation observables in heavy-ion collisions. The physics implications and the future second phase of the beam energy scan (2019–2020) at RHIC will also be discussed.
作者机构：
[Jia, Ya; Lu, Lulu; Yang, Lijian] Cent China Normal Univ, Inst Biophys, Wuhan 430079, Hubei, Peoples R China.;[Jia, Ya; Lu, Lulu; Yang, Lijian] Cent China Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.;[Liu, Wangheng] Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Jia, Ya] C;Cent China Normal Univ, Inst Biophys, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Dept Phys, Wuhan 430079, Hubei, Peoples R China.
期刊：
Journal of High Energy Physics,2017年2017(8):1-31 ISSN：1029-8479
通讯作者：
S. Bifani
作者机构：
[Di Canto, A.; Durante, P.; Ferro-Luzzi, M.; Bozzi, C.; Fontana, M.; Kvaratskheliya, T.; Ponce, S.; Karacson, M.; Merli, A.; Byczynski, W.; Hatch, M.; Rih, M.; Forty, R.; Corti, G.; McCann, M.; Schmidt, B.; Gaspar, C.; Perez, D. H. Campora; Roiser, S.; Wyllie, K.; Dordei, F.; Contu, A.; Lacarrere, D.; Leflat, A.; Cattaneo, M.; Jost, B.; Farber, C.; Dungs, K.; Siddi, B. G.; Lindner, R.; Dijkstra, H.; Thomas, E.; Funk, W.; Palutan, M.; Golutvin, A.; Lemaitre, F.; Collins, P.; Jacobsson, R.; Neufeld, N.; Buytaert, J.; Frei, C.; Aaij, R.; Mathe, Z.; Grillo, L.; Stagni, F.; Pearce, A.; Teubert, F.; Lupton, O.; Perazzini, S.; Gys, T.; Wilkinson, G.; Frank, M.; Clemencic, M.; Williams, M.; Valassi, A.; Alessio, F.; Trisovic, A.; Fohl, K.; Popov, D.; Matev, R.; Cardoso, L. A. Granado; Joram, C.; Altarelli, M. Pepe; Barschel, C.; Charpentier, Ph.; Ruf, T.; Neri, N.; Poikela, T.; Whitehead, M.; Stahl, S.; Bettler, M. -O.; Gruber, L.; Schopper, A.; Couturier, B.; Cavallero, G.; Vagner, A.; Salzgeber, M. Ravonel; Schindler, H.; Haen, C.; Barbosa, J. V. Viana; Dziurda, A.; Johnson, D.; Schwemmer, R.; Vagnoni, V.; D'Ambrosio, C.; Declara, P. Fernandez; Closier, J.; van Herwijnen, E.; Coombs, G.; Valat, S.; Sridharan, S.; Colombo, T.] European Org Nucl Res CERN, Geneva, Switzerland.;[Tourinho Jadallah Aoude, R.; Massafferri, A.; De Miranda, J. M.; Salustino Guimaraes, V.; Soares Lavra, I.; Gomes, A.; Molina Rodriguez, J.; Bediaga, I.; Rodrigues, A. B.; dos Reis, A. C.] CBPF, Rio De Janeiro, Brazil.;[Lopes, J. H.; Martins Tostes, D.; Goicochea, J. M. Otalora; Polycarpo, E.; Souza De Paula, B.; Gandelman, M.; Rangel, M. S.; Ferreira Rodrigues, F.; Hicheur, A.; Carvalho Akiba, K.; Potterat, C.; Silva de Oliveira, L.; De Paula, L.; Nasteva, I.; Da Cunha Marinho, F.; Amato, S.] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil.;[Gao, Y.; Yang, Z.; Jiang, F.; Li, T.; Zhu, X.; An, L.; Davis, A.; Zhang, L.; Liu, X.] Tsinghua Univ, Ctr High Energy Phys, Beijing, Peoples R China.;[Chefdeville, M.; Decamp, D.; Tourneur, S.; Reboud, M.; Beaucourt, L.; T'Jampens, S.; Marchand, J. F.; Tisserand, V.; Xu, Z.; Ghez, Ph.; Pietrzyk, B.; Minard, M. -N.; Deleage, N.] Univ Savoie Mont Blanc, CNRS, LAPP, IN2P3, Annecy Le Vieux, France.
通讯机构：
[S. Bifani] U;University of Birmingham, Birmingham, United Kingdom
关键词：
B physics;Branching fraction;Hadron-Hadron scattering (experiments);Rare decay
摘要：
A test of lepton universality, performed by measuring the ratio of the branching fractions of the B
0 → K
*0
μ
+
μ
− and B
0 → K
*0
e
+
e
− decays,
$$ {R}_{K^{*0}} $$
, is presented. The K
*0 meson is reconstructed in the final state K
+
π
−, which is required to have an invariant mass within 100 MeV/c
2 of the known K
*(892)0 mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ratio is measured in two regions of the dilepton invariant mass squared, q
2, to be
$$ {R}_{K^{*0}}=\left\{\begin{array}{l}{0.66_{-}^{+}}_{0.07}^{0.11}\left(\mathrm{stat}\right)\pm 0.03\left(\mathrm{syst}\right)\kern1em \mathrm{f}\mathrm{o}\mathrm{r}\kern1em 0.045<{q}^2<1.1\kern0.5em {\mathrm{GeV}}^2/{c}^4,\hfill \\ {}{0.69_{-}^{+}}_{0.07}^{0.11}\left(\mathrm{stat}\right)\pm 0.05\left(\mathrm{syst}\right)\kern1em \mathrm{f}\mathrm{o}\mathrm{r}\kern1em 1.1<{q}^2<6.0\kern0.5em {\mathrm{GeV}}^2/{c}^4.\hfill \end{array}\right. $$
The corresponding 95.4% confidence level intervals are [0.52, 0.89] and [0.53, 0.94]. The results, which represent the most precise measurements of
$$ {R}_{K^{*0}} $$
to date, are compatible with the Standard Model expectations at the level of 2.1–2.3 and 2.4–2.5 standard deviations in the two q
2 regions, respectively.
期刊：
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,2017年139(9):3513-3521 ISSN：0002-7863
通讯作者：
Wang, Jianfang;Zhang, Lizhi
作者机构：
[Wang, Jianfang; Li, Hao; Cui, Ximin; Qin, Feng] Chinese Univ Hong Kong, Dept Phys, Shatin, Hong Kong, Peoples R China.;[Zhang, Lizhi; Yang, Zhiping; Li, Hao] Cent China Normal Univ, Inst Environm Chem, Coll Chem, Key Lab Pesticide & Chem Biol,Minist Educ, Wuhan 430079, Peoples R China.
通讯机构：
[Wang, Jianfang; Zhang, Lizhi] C;Chinese Univ Hong Kong, Dept Phys, Shatin, Hong Kong, Peoples R China.;Cent China Normal Univ, Inst Environm Chem, Coll Chem, Key Lab Pesticide & Chem Biol,Minist Educ, Wuhan 430079, Peoples R China.
摘要：
Selective organic transformation under mild conditions constitutes a challenge in green chemistry, especially for alcohol oxidation, which typically requires environmentally unfriendly oxidants. Here, we report a new plasmonic catalyst of Au supported on BiOCl containing oxygen vacancies. It photocatalyzes selective benzyl alcohol oxidation with O-2 under visible light through synergistic action of plasmonic hot electrons and holes. Oxygen vacancies on BiOCl facilitate the trapping and transfer of plasmonic hot electrons to adsorbed O-2, producing center dot O-2(-) radicals, while plasmonic hot holes remaining on the Au surface mildly oxidize benzyl alcohol to corresponding carbon-centered radicals. The hypothesized concerted ring addition between these two radical species on the BiOCI surface highly favors the production of benzaldehyde along with an unexpected oxygen atom transfer from O-2 to the product. The results and understanding acquired in this study, based on the full utilization of hot charge carriers in a plasmonic metal deposited on a rationally designed support, will contribute to the development of more active and/or selective plasmonic catalysts for a wide variety of organic transformations.
摘要：
Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (
$\sqrt{s_{NN}}=$
2.7--4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (
$\mu_B > 500$
MeV), effects of chiral symmetry, and the equation of state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2024, in the context of the worldwide efforts to explore high-density QCD matter.
