Exploring Lifetime Effects in Femtoscopy

We investigate the role of lifetime effects from resonances and emission duration tails in femtoscopy at RHIC in two Blast-Wave models. We find the non-Gaussian components compare well with published source imaged data, but the value of R_out obtained from Gaussian fits is not insensitive to the non-Gaussian contributions when realistic acceptance cuts are applied to models.Comment: 5 pages, 2 figure

Solution of the RHIC HBT puzzle with Gaussian initial conditions

It is argued that the consistent description of the transverse-momentum spectra, elliptic flow, and the HBT radii in the relativistic heavy-ion collisions studied at RHIC may be obtained within the hydrodynamic model if one uses the Gaussian profile for the initial energy density in the transverse plane. Moreover, we show that the results obtained in the scenario with an early start of hydrodynamics (at the proper time tau0 = 0.25 fm) are practically equivalent to the results obtained in the model where the hydrodynamics is preceded by the free-streaming stage of partons (in the proper time interval 0.25 fm < tau < 1 fm) which suddenly equilibrate and with the help of the Landau matching conditions are transformed into the hydrodynamic regime (at the proper time tau0 = 1 fm).Comment: talk presented by WF at SQM2008 Conferenc

Highly-anisotropic and strongly-dissipative hydrodynamics with transverse expansion

A recently formulated framework of highly-anisotropic and strongly-dissipative hydrodynamics (ADHYDRO) is used to describe the evolution of matter created in ultra-relativistic heavy-ion collisions. New developments of the model contain: the inclusion of asymmetric transverse expansion (combined with the longitudinal boost-invariant flow) and comparisons of the model results with the RHIC data, which have become possible after coupling of ADHYDRO with THERMINATOR. Various soft-hadronic observables (the transverse-momentum spectra, the elliptic flow coefficient v_2, and the HBT radii) are calculated for different initial conditions characterized by the value of the initial pressure asymmetry. We find that as long as the initial energy density profile is unchanged the calculated observables remain practically the same. This result indicates the insensitivity of the analyzed observables to the initial anisotropy of pressure and suggests that the complete thermalization of the system may be delayed to easily acceptable times of about 1 fm/c

Early dynamics of transversally thermalized matter

We argue that the idea that the parton system created in relativistic heavy-ion collisions is formed in a state with transverse momenta close to thermodynamic equilibrium and its subsequent dynamics at early times is dominated by pure transverse hydrodynamics of the perfect fluid is compatible with the data collected at RHIC. This scenario of early parton dynamics may help to solve the problem of early equilibration.Comment: 4 pages, 2 figures, Talk given by M. Chojnacki at Quark Matter 2008, Jaipur, Indi

Laboratory Characterization and Astrophysical Detection of Vibrationally Excited States of Vinyl Cyanide in Orion-KL

New laboratory data of CH$_2$CHCN (vinyl cyanide) in its ground and vibrationally excited states at the microwave to THz domain allow searching for these excited state transitions in the Orion-KL line survey. Frequency-modulated spectrometers combined into a single broadband 50-1900 GHz spectrum provided measurements of CH$_2$CHCN covering a spectral range of 18-1893 GHz, whose assignments was confirmed by Stark modulation spectra in the 18-40 GHz region and by ab-initio anharmonic force field calculations. For analyzing the emission lines of CH$_2$CHCN species detected in Orion-KL we used the excitation and radiative transfer code (MADEX) at LTE conditions. The rotational transitions of the ground state of this molecule emerge from four cloud components of hot core nature which trace the physical and chemical conditions of high mass star forming regions in the Orion-KL Nebula. The total column density of CH$_2$CHCN in the ground state is (3.0$\pm$0.9)x10$^{15}$ cm$^{-2}$. We report on the first interstellar detection of transitions in the v10=1/(v11=1,v15=1) dyad in space, and in the v11=2 and v11=3 states in Orion-KL. The lowest energy vibrationally excited states of vinyl cyanide such as v11=1 (at 328.5 K), v15=1 (at 478.6 K), v11=2 (at 657.8 K), the v10=1/(v11=1,v15=1) dyad (at 806.4/809.9 K), and v11=3 (at 987.9 K) are populated under warm and dense conditions, so they probe the hottest parts of the Orion-KL source. Column density and rotational and vibrational temperatures for CH$_2$CHCN in their ground and excited states, as well as for the isotopologues, have been constrained by means of a sample of more than 1000 lines in this survey. Moreover, we present the detection of methyl isocyanide (CH$_3$NC) for the first time in Orion-KL and a tentative detection of vinyl isocyanide (CH$_2$CHNC) and give column density ratios between the cyanide and isocyanide isomers.Comment: 46 pages, 22 figures, 14 tables, 9 online table

Altering the properties of graphene on Cu(111) by intercalation of potassium bromide

The catalytic growth on transition metal surfaces provides a clean and controllable route to obtain defect-free, monocrystalline graphene. However, graphene's optical and electronic properties are diminished by the interaction with the metal substrate. One way to overcome this obstacle is the intercalation of atoms and molecules decoupling the graphene and restoring its electronic structure. We applied noncontact atomic force microscopy to study the structural and electric properties of graphene on clean Cu(111) and after the adsorption of KBr or NaCl. By means of Kelvin probe force microscopy, a change in graphene's work function has been observed after the deposition of KBr, indicating a changed graphene-substrate interaction. Further measurements of single-electron charging events as well as X-ray photoelectron spectroscopy confirmed an electronic decoupling of the graphene islands by KBr intercalation. The results have been compared with density functional theory calculations, supporting our experimental findings

Exploring Lifetime Effects in Femtoscopy

We investigate the role of lifetime effects from resonances and emission duration tails in femtoscopy at RHIC in two Blast-Wave models. We find the non-Gaussian components compare well with published source imaged data, but the value of R{sub out} obtained from Gaussian fits is not insensitive to the non-Gaussian contributions when realistic acceptance cuts are applied to models

Solid-state reference electrodes based on carbon nanotubes and polyacrylate membranes

A novel potentiometric solid-state reference electrode containing single-walled carbon nanotubes as the transducer layer between a polyacrylate membrane and the conductor is reported here. Single-walled carbon nanotubes act as an efficient transducer of the constant potentiometric signal originating from the reference membrane containing the Ag/AgCl/Cl− ions system, and they are needed to obtain a stable reference potentiometric signal. Furthermore, we have taken advantage of the light insensitivity of single-walled carbon nanotubes to improve the analytical performance characteristics of previously reported solid-state reference electrodes. Four different polyacrylate polymers have been selected in order to identify the most efficient reservoir for the Ag/AgCl system. Finally, two different arrangements have been assessed: (1) a solid-state reference electrode using photo-polymerised n-butyl acrylate polymer and (2) a thermo-polymerised methyl methacrylate:n-butyl acrylate (1:10) polymer. The sensitivity to various salts, pH and light, as well as time of response and stability, has been tested: the best results were obtained using single-walled carbon nanotubes and photo-polymerised n-butyl acrylate polymer. Water transport plays an important role in the potentiometric performance of acrylate membranes, so a new screening test method has been developed to qualitatively assess the difference in water percolation between the polyacrylic membranes studied. The results presented here open the way for the true miniaturisation of potentiometric systems using the excellent properties of single-walled carbon nanotubes

Simultaneous measurement of the muon neutrino charged-current cross section on oxygen and carbon without pions in the final state at T2K

Authors: K. Abe,56 N. Akhlaq,45 R. Akutsu,57 A. Ali,32 C. Alt,11 C. Andreopoulos,54,34 L. Anthony,21 M. Antonova,19 S. Aoki,31 A. Ariga,2 T. Arihara,59 Y. Asada,69 Y. Ashida,32 E. T. Atkin,21 Y. Awataguchi,59 S. Ban,32 M. Barbi,46 G. J. Barker,66 G. Barr,42 D. Barrow,42 M. Batkiewicz-Kwasniak,15 A. Beloshapkin,26 F. Bench,34 V. Berardi,22 L. Berns,58 S. Bhadra,70 S. Bienstock,53 S. Bolognesi,6 T. Bonus,68 B. Bourguille,18 S. B. Boyd,66 A. Bravar,13 D. Bravo Berguño,1 C. Bronner,56 S. Bron,13 A. Bubak,51 M. Buizza Avanzini ,10 T. Campbell,7 S. Cao,16 S. L. Cartwright,50 M. G. Catanesi,22 A. Cervera,19 D. Cherdack,17 N. Chikuma,55 G. Christodoulou,12 M. Cicerchia,24,† J. Coleman,34 G. Collazuol,24 L. Cook,42,28 D. Coplowe,42 A. Cudd,7 A. Dabrowska,15 G. De Rosa,23 T. Dealtry,33 S. R. Dennis,34 C. Densham,54 F. Di Lodovico,30 N. Dokania,39 S. Dolan,12 T. A. Doyle,33 O. Drapier,10 J. Dumarchez,53 P. Dunne,21 A. Eguchi,55 L. Eklund,14 S. Emery-Schrenk,6 A. Ereditato,2 A. J. Finch,33 G. Fiorillo,23 C. Francois,2 M. Friend,16,‡ Y. Fujii,16,‡ R. Fujita,55 D. Fukuda,40 R. Fukuda,60 Y. Fukuda,37 K. Fusshoeller,11 C. Giganti,53 M. Gonin,10 A. Gorin,26 M. Guigue,53 D. R. Hadley,66 J. T. Haigh,66 P. Hamacher-Baumann,49 M. Hartz,62,28 T. Hasegawa,16,‡ S. Hassani,6 N. C. Hastings,16 Y. Hayato,56,28 A. Hiramoto,32 M. Hogan,8 J. Holeczek,51 N. T. Hong Van,20,27 T. Honjo,41 F. Iacob,24 A. K. Ichikawa,32 M. Ikeda,56 T. Ishida,16,‡ M. Ishitsuka,60 K. Iwamoto,55 A. Izmaylov,26 N. Izumi,60 M. Jakkapu,16 B. Jamieson,67 S. J. Jenkins,50 C. Jesús-Valls,18 M. Jiang,32 P. Jonsson,21 C. K. Jung,39,§ X. Junjie,57 P. B. Jurj,21 M. Kabirnezhad,42 A. C. Kaboth,48,54 T. Kajita,57,§ H. Kakuno,59 J. Kameda,56 D. Karlen,63,62 S. P. Kasetti,35 Y. Kataoka,56 Y. Katayama,69 T. Katori,30 Y. Kato,56 E. Kearns,3,28,§ M. Khabibullin,26 A. Khotjantsev,26 T. Kikawa,32 H. Kikutani,55 H. Kim,41 S. King,30 J. Kisiel,51 A. Knight,66 T. Kobata,41 T. Kobayashi,16,‡ L. Koch,42 T. Koga,55 A. Konaka,62 L. L. Kormos,33 Y. Koshio,40,§ A. Kostin,26 K. Kowalik,38 H. Kubo,32 Y. Kudenko,26,∥ N. Kukita,41 S. Kuribayashi,32 R. Kurjata,65 T. Kutter,35 M. Kuze,58 L. Labarga,1 J. Lagoda,38 M. Lamoureux,24 D. Last,43 M. Lawe,33 M. Licciardi,10 R. P. Litchfield,14 S. L. Liu,39 X. Li,39 A. Longhin,24 L. Ludovici,25 X. Lu,42 T. Lux,18 L. N. Machado,23 L. Magaletti,22 K. Mahn,36 M. Malek,50 S. Manly,47 L. Maret,13 A. D. Marino,7 L. Marti-Magro,56,28 T. Maruyama,16,‡ T. Matsubara,16 K. Matsushita,55 V. Matveev,26 C. Mauger,43 K. Mavrokoridis,34 E. Mazzucato,6 N. McCauley,34 J. McElwee,50 K. S. McFarland,47 C. McGrew,39 A. Mefodiev,26 C. Metelko,34 M. Mezzetto,24 A. Minamino,69 O. Mineev,26 S. Mine,5 M. Miura,56,§ L. Molina Bueno,11 S. Moriyama,56,§ Th. A. Mueller,10 L. Munteanu,6 S. Murphy,11 Y. Nagai,7 T. Nakadaira,16,‡ M. Nakahata,56,28 Y. Nakajima,56 A. Nakamura,40 K. Nakamura,28,16,‡ S. Nakayama,56,28 T. Nakaya,32,28 K. Nakayoshi,16,‡ C. E. R. Naseby,21 T. V. Ngoc,20,¶ K. Niewczas,68 K. Nishikawa,16,* Y. Nishimura,29 E. Noah,13 T. S. Nonnenmacher,21 F. Nova,54 P. Novella,19 J. Nowak,33 J. C. Nugent,14 H. M. O’Keeffe,33 L. O’Sullivan,50 T. Odagawa,32 T. Ogawa,16 R. Okada,40 K. Okumura,57,28 T. Okusawa,41 S. M. Oser,4,62 R. A. Owen,45 Y. Oyama,16,‡ V. Palladino,23 V. Paolone,44 M. Pari,24 W. C. Parker,48 S. Parsa,13 J. Pasternak,21 M. Pavin,62 D. Payne,34 G. C. Penn,34 L. Pickering,36 C. Pidcott,50 G. Pintaudi,69 C. Pistillo,2 B. Popov,53,** K. Porwit,51 M. Posiadala-Zezula,64 A. Pritchard,34 B. Quilain,10 T. Radermacher,49 E. Radicioni,22 B. Radics,11 P. N. Ratoff,33 C. Riccio,39 E. Rondio,38 S. Roth,49 A. Rubbia,11 A. C. Ruggeri,23 C. Ruggles,14 A. Rychter,65 K. Sakashita,16,‡ F. Sánchez,13 G. Santucci,70 C. M. Schloesser,11 K. Scholberg,9,§ M. Scott,21 Y. Seiya,41,†† T. Sekiguchi,16,‡ H. Sekiya,56,28,§ D. Sgalaberna,11 A. Shaikhiev,26 A. Shaykina,26 M. Shiozawa,56,28 W. Shorrock,21 A. Shvartsman,26 M. Smy,5 J. T. Sobczyk,68 H. Sobel,5,28 F. J. P. Soler,14 Y. Sonoda,56 S. Suvorov,26,6 A. Suzuki,31 S. Y. Suzuki,16,‡ Y. Suzuki,28 A. A. Sztuc,21 M. Tada,16,‡ M. Tajima,32 A. Takeda,56 Y. Takeuchi,31,28 H. K. Tanaka,56,§ H. A. Tanaka,52,61 S. Tanaka,41 Y. Tanihara,69 N. Teshima,41 L. F. Thompson,50 W. Toki,8 C. Touramanis,34 T. Towstego,61 K. M. Tsui,34 T. Tsukamoto,16,‡ M. Tzanov,35 Y. Uchida,21 M. Vagins,28,5 S. Valder,66 Z. Vallari,39 D. Vargas,18 G. Vasseur,6 W. G. S. Vinning,66 T. Vladisavljevic,54 V. V. Volkov,26 T. Wachala,15 J. Walker,67 J. G. Walsh,33 Y. Wang,39 D. Wark,54,42 M. O. Wascko,21 A. Weber,54,42 R. Wendell,32,§ M. J. Wilking,39 C. Wilkinson,2 J. R. Wilson,30 K. Wood,39 C. Wret,47 K. Yamamoto,41,†† C. Yanagisawa,39,‡‡ G. Yang,39 T. Yano,56 K. Yasutome,32 N. Yershov,26 M. Yokoyama,55,§ T. Yoshida,58 M. Yu,70 A. Zalewska,15 J. Zalipska,38 K. Zaremba,65 G. Zarnecki,38 M. Ziembicki,65 E. D. Zimmerman,7 M. Zito,53 S. Zsoldos,30 and A. Zykova26 (T2K Collaboration)This paper reports the first simultaneous measurement of the double differential muon neutrino chargedcurrent cross section on oxygen and carbon without pions in the final state as a function of the outgoing muon kinematics, made at the ND280 off-axis near detector of the T2K experiment. The ratio of the oxygen and carbon cross sections is also provided to help validate various models’ ability to extrapolate between carbon and oxygen nuclear targets, as is required in T2K oscillation analyses. The data are taken using a neutrino beam with an energy spectrum peaked at 0.6 GeV. The extracted measurement is compared with the prediction from different Monte Carlo neutrino-nucleus interaction event generators, showing particular model separation for very forward-going muons. Overall, of the models tested, the result is best described using local Fermi gas descriptions of the nuclear ground state with RPA suppression