The Baryon Oscillation Spectroscopic Survey of SDSS-III
Dawson, Kyle S; Ahn, Christopher P; Anderson, Scott F; Aubourg, Eric; Bailey, Stephen; Barkhouser, Robert H; Bautista, Julian E; Beifiori, Alessandra; Berlind, Andreas A; Bhardwaj, Vaishali; Bizyaev, Dmitry; Blake, Cullen H; Blanton, Michael R; Blomqvist, Michael; Bolton, Adam S; Borde, Arnaud; Bovy, Jo; Brandt, W N; Brewington, Howard; Brinkmann, Jon; Brown, Peter J; Brownstein, Joel R; Bundy, Kevin; Busca, N G; Carithers, William; Carnero, Aurelio R; Carr, Michael A; Chen, Yanmei; Comparat, Johan; Connolly, Natalia; Cope, Frances; Croft, Rupert A C; Cuesta, Antonio J; da Costa, Luiz N; Davenport, James R A; Delubac, Timothee; de Putter, Roland; Dhital, Saurav; Ealet, Anne; Ebelke, Garrett L; Eisenstein, Daniel J; Escoffier, S; Fan, Xiaohui; Ak, N Filiz; Finley, Hayley; Font-Ribera, Andreu; Genova-Santos, R; Gunn, James E; Guo, Hong; Haggard, Daryl; Hall, Patrick B; Hamilton, Jean-Christophe; Harris, Ben; Harris, David W; Ho, Shirley; Hogg, David W; Holder, Diana; Honscheid, Klaus; Huehnerhoff, Joe; Jordan, Beatrice; Jordan, Wendell P; Kauffmann, Guinevere; Kazin, Eyal A; Kirkby, David; Klaene, Mark A; Kneib, Jean-Paul; Goff, Jean-Marc Le; Lee, Khee-Gan; Long, Daniel C; Loomis, Craig P; Lundgren, Britt; Lupton, Robert H; Maia, Marcio A G; Makler, Martin; Malanushenko, Elena; Malanushenko, Viktor; Mandelbaum, Rachel; Manera, Marc; Maraston, Claudia; Margala, Daniel; Masters, Karen L; McBride, Cameron K; McDonald, Patrick; McGreer, Ian D; Mena, Olga; Miralda-Escude, Jordi; Montero-Dorta, Antonio D; Montesano, Francesco; Muna, Demitri; Myers, Adam D; Naugle, Tracy; Nichol, Robert C; Noterdaeme, Pasquier; Olmstead, Matthew D; Oravetz, Audrey; Oravetz, Daniel J; Owen, Russell; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John K; Paris, Isabelle; Percival, Will J; Perez-Fournon, Ismael; Perez-Rafols, Ignasi; Petitjean, Patrick; Pfaffenberger, Robert; Pforr, Janine; Pieri, Matthew M; Prada, Francisco; Price-Whelan, Adrian M; Raddick, M Jordan; Rebolo, Rafael; Rich, James; Richards, Gordon T; Rockosi, Constance M; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Rossi, Graziano; Rubino-Martin, J A; Samushia, Lado; Sanchez, Ariel G; Sayres, Conor; Schmidt, Sarah J; Schneider, Donald P; Scoccola, C G; Seo, Hee-Jong; Shelden, Alaina; Sheldon, Erin; Shen, Yue; Shu, Yiping; Slosar, Anze; Smee, Stephen A; Snedden, Stephanie A; Stauffer, Fritz; Steele, Oliver; Strauss, Michael A; Suzuki, Nao; Swanson, Molly E C; Tal, Tomer; Tanaka, Masayuki; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Tremonti, Christy A; Magana, M Vargas; Verde, Licia; Viel, Matteo; Wake, David A; Watson, Mike; Weaver, Benjamin A; Weinberg, David H; Weiner, Benjamin J; West, Andrew A; White, Martin; Wood-Vasey, W M; Yeche, Christophe; Zehavi, Idit; Zhao, Gong-Bo; Zheng, Zheng
2012-01-01
The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses luminous galaxies to measure BAO to redshifts z<0.7 and observations of neutral hydrogen in the Lyman alpha forest in quasar spectra to constrain BAO over the redshift range 2.15
Ross, Ashley J; Chuang, Chia-Hsun; Pellejero-Ibanez, Marcos; Seo, Hee-Jong; Vargas-Magana, Mariana; Cuesta, Antonio J; Percival, Will J; Burden, Angela; Sanchez, Ariel G; Grieb, Jan Niklas; Reid, Beth; Brownstein, Joel R; Dawson, Kyle S; Eisenstein, Daniel J; Ho, Shirley; Kitaura, Francisco-Shu; Nichol, Robert C; Olmstead, Matthew D; Prada, Francisco; Rodriguez-Torres, Sergio A; Saito, Shun; Salazar-Albornoz, Salvador; Schneider, Donald P; Thomas, Daniel; Tinker, Jeremy; Tojeiro, Rita; Wang, Yuting; White, Martin; Zhao, Gong-bo
2016-01-01
We present baryon acoustic oscillation (BAO) scale measurements determined from the clustering of 1.2 million massive galaxies with redshifts 0.2 < z < 0.75 distributed over 9300 square degrees, as quantified by their redshift-space correlation function. In order to facilitate these measurements, we define, describe, and motivate the selection function for galaxies in the final data release (DR12) of the SDSS III Baryon Oscillation Spectroscopic Survey (BOSS). This includes the observational footprint, masks for image quality and Galactic extinction, and weights to account for density relationships intrinsic to the imaging and spectroscopic portions of the survey. We simulate the observed systematic trends in mock galaxy samples and demonstrate that they impart no bias on baryon acoustic oscillation (BAO) scale measurements and have a minor impact on the recovered statistical uncertainty. We measure transverse and radial BAO distance measurements in 0.2 < z < 0.5, 0.5 < z < 0.75, and (overla...
Anderson, Lauren; Bailey, Stephen; Bizyaev, Dmitry; Blanton, Michael; Bolton, Adam S; Brinkmann, J; Brownstein, Joel R; Burden, Angela; Cuesta, Antonio J; da Costa, Luiz N A; Dawson, Kyle S; de Putter, Roland; Eisenstein, Daniel J; Gunn, James E; Guo, Hong; Hamilton, Jean-Christophe; Harding, Paul; Ho, Shirley; Honscheid, Klaus; Kazin, Eyal; Kirkby, D; Kneib, Jean-Paul; Labatie, Antione; Loomis, Craig; Lupton, Robert H; Malanushenko, Elena; Malanushenko, Viktor; Mandelbaum, Rachel; Manera, Marc; Maraston, Claudia; McBride, Cameron K; Mehta, Kushal T; Mena, Olga; Montesano, Francesco; Muna, Demetri; Nichol, Robert C; Nuza, Sebastian E; Olmstead, Matthew D; Oravetz, Daniel; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John; Paris, Isabelle; Percival, Will J; Petitjean, Patrick; Prada, Francisco; Reid, Beth; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Samushia, Lado; Sanchez, Ariel G; Schneider, David J Schlegel Donald P; Scoccola, Claudia G; Seo, Hee-Jong; Sheldon, Erin S; Simmons, Audrey; Skibba, Ramin A; Strauss, Michael A; Swanson, Molly E C; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Magana, Mariana Vargas; Verde, Licia; Wagner, Christian; Wake, David A; Weaver, Benjamin A; Weinberg, David H; White, Martin; Xu, Xiaoying; Yeche, Christophe; Zehavi, Idit; Zhao, Gong-Bo
2012-01-01
We present measurements of galaxy clustering from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey III (SDSS-III). These use the Data Release 9 (DR9) CMASS sample, which contains 264,283 massive galaxies covering 3275 square degrees with an effective redshift z=0.57 and redshift range 0.43 < z < 0.7. Assuming a concordance Lambda-CDM cosmological model, this sample covers an effective volume of 2.2 Gpc^3, and represents the largest sample of the Universe ever surveyed at this density, n = 3 x 10^-4 h^-3 Mpc^3. We measure the angle-averaged galaxy correlation function and power spectrum, including density-field reconstruction of the baryon acoustic oscillation (BAO) feature. The acoustic features are detected at a significance of 5\\sigma in both the correlation function and power spectrum. Combining with the SDSS-II Luminous Red Galaxy Sample, the detection significance increases to 6.7\\sigma. Fitting for the position of the acoustic features measures the ...
The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Overview and Early Data
Dawson, Kyle S; Percival, Will J; Alam, Shadab; Albareti, Franco D; Anderson, Scott F; Armengaud, Eric; Aubourg, Eric; Bailey, Stephen; Bautista, Julian E; Berlind, Andreas A; Bershady, Matthew A; Beutler, Florian; Bizyaev, Dmitry; Blanton, Michael R; Blomqvist, Michael; Bolton, Adam S; Bovy, Jo; Brandt, W N; Brinkmann, Jon; Brownstein, Joel R; Burtin, Etienne; Busca, N G; Cai, Zheng; Chuang, Chia-Hsun; Clerc, Nicolas; Comparat, Johan; Cope, Frances; Croft, Rupert A C; Cruz-Gonzalez, Irene; da Costa, Luiz N; Cousinou, Marie-Claude; Darling, Jeremy; de la Torre, Sylvain; Delubac, Timothee; Bourboux, Helion du Mas des; Dwelly, Tom; Ealet, Anne; Eisenstein, Daniel J; Eracleous, Michael; Escoffier, S; Fan, Xiaohui; Finoguenov, Alexis; Font-Ribera, Andreu; Frinchaboy, Peter; Gaulme, Patrick; Georgakakis, Antonis; Green, Paul; Guo, Hong; Guy, Julien; Ho, Shirley; Holder, Diana; Huehnerhoff, Joe; Hutchinson, Timothy; Jing, Yipeng; Jullo, Eric; Kamble, Vikrant; Kinemuchi, Karen; Kirkby, David; Kitaura, Francisco-Shu; Klaene, Mark A; Laher, Russ R; Lang, Dustin; Laurent, Pierre; Goff, Jean-Marc Le; Li, Cheng; Liang, Yu; Lima, Marcos; Lin, Qiufan; Lin, Weipeng; Lin, Yen-Ting; Long, Daniel C; Lundgren, Britt; MacDonald, Nicholas; Maia, Marcio Antonio Geimba; Malanushenko, Elena; Malanushenko, Viktor; Mariappan, Vivek; McBride, Cameron K; McGreer, Ian D; Menard, Brice; Merloni, Andrea; Meza, Andres; Montero-Dorta, Antonio D; Muna, Demitri; Myers, Adam D; Nandra, Kirpal; Naugle, Tracy; Newman, Jeffrey A; Noterdaeme, Pasquier; Nugent, Peter; Ogando, Ricardo; Olmstead, Matthew D; Oravetz, Audrey; Oravetz, Daniel J; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John K; Paris, Isabelle; Peacock, John A; Petitjean, Patrick; Pieri, Matthew M; Pisani, Alice; Prada, Francisco; Prakash, Abhishek; Raichoor, Anand; Reid, Beth; Rich, James; Ridl, Jethro; Rodriguez-Torres, Sergio; Rosell, Aurelio Carnero; Ross, Ashley J; Rossi, Graziano; Ruan, John; Salvato, Mara; Sayres, Conor; Schneider, Donald P; Schlegel, David J; Seljak, Uros; Seo, Hee-Jong; Sesar, Branimir; Shandera, Sarah; Shu, Yiping; Slosar, Anze; Sobreira, Flavia; Strauss, Michael A; Streblyanska, Alina; Suzuki, Nao; Tao, Charling; Tinker, Jeremy L; Tojeiro, Rita; Vargas-Magana, Mariana; Wang, Yuting; Weaver, Benjamin A; Weinberg, David H; White, Martin; Wood-Vasey, W M; Yeche, Christophe; Zhai, Zhongxu; Zhao, Cheng; Zhao, Gong-bo; Zheng, Zheng; Zhu, Guangtun Ben; Zou, Hu
2015-01-01
The Extended Baryon Oscillation Spectroscopic Survey (eBOSS) will conduct novel cosmological observations using the BOSS spectrograph at Apache Point Observatory. Observations will be simultaneous with the Time Domain Spectroscopic Survey (TDSS) designed for variability studies and the Spectroscopic Identification of eROSITA Sources (SPIDERS) program designed for studies of X-ray sources. eBOSS will use four different tracers to measure the distance-redshift relation with baryon acoustic oscillations (BAO) in the clustering of matter. Using more than 250,000 new, spectroscopically confirmed luminous red galaxies at a median redshift z=0.72, we project that eBOSS will yield measurements of $d_A(z)$ to an accuracy of 1.2% and measurements of H(z) to 2.1% when combined with the z>0.6 sample of BOSS galaxies. With ~195,000 new emission line galaxy redshifts, we expect BAO measurements of $d_A(z)$ to an accuracy of 3.1% and H(z) to 4.7% at an effective redshift of z= 0.87. A sample of more than 500,000 spectroscop...
The SDSS-IV extended Baryonic Oscillation Spectroscopic Survey: Quasar Target Selection
Myers, Adam D; Prakash, Abhishek; Pâris, Isabelle; Yeche, Christophe; Dawson, Kyle S; Bovy, Jo; Lang, Dustin; Schlegel, David J; Newman, Jeffrey A; Petitjean, Patrick; Kneib, Jean Paul; Laurent, Pierre; Percival, Will J; Ross, Ashley J; Seo, Hee-Jong; Tinker, Jeremy L; Armengaud, Eric; Brownstein, Joel; Burtin, Etienne; Cai, Zheng; Comparat, Johan; Kasliwal, Mansi; Kulkarni, Shrinivas R; Laher, Russ; Levitan, David; McBride, Cameron K; McGreer, Ian D; Miller, Adam A; Nugent, Peter; Ofek, Eran; Rossi, Graziano; Ruan, John; Schneider, Donald P; Sesar, Branimir; Streblyanska, Alina; Surace, Jason
2015-01-01
As part of the SDSS-IV the extended Baryon Oscillation Spectroscopic Survey (eBOSS) will perform measurements of the cosmological distance scale via application of the Baryon Acoustic Oscillation (BAO) method to samples of quasars and galaxies. Quasar surveys are particularly useful in the BAO context as they can trace extremely large volumes back to moderately high redshift. eBOSS will adopt two approaches to target quasars over a 7500 sq. deg. area. First, z > 2.1 quasars will be targeted to improve BAO measurements in the Lyman-Alpha Forest. Second, a homogeneously selected "CORE" sample of quasars at 0.9 2.1 quasars. A supplemental selection based on variability of quasars in multi-epoch imaging from the Palomar Transient Factory should recover an additional ~3-4 per sq. deg. z > 2.1 quasars to g 500,000 new spectroscopically confirmed quasars and > 500,000 uniformly selected spectroscopically confirmed 0.9 < z < 2.2 quasars. At the conclusion of SDSS-IV, the SDSS will have provided unique spectra...
Anderson, Lauren; Bailey, Stephen; Beutler, Florian; Bhardwaj, Vaishali; Blanton, Michael; Bolton, Adam S; Brinkmann, J; Brownstein, Joel R; Burden, Angela; Chuang, Chia-Hsun; Cuesta, Antonio J; Dawson, Kyle S; Eisenstein, Daniel J; Escoffier, Stephanie; Gunn, James E; Guo, Hong; Ho, Shirley; Honscheid, Klaus; Howlett, Cullan; Kirkby, David; Lupton, Robert H; Manera, Marc; Maraston, Claudia; McBride, Cameron K; Mena, Olga; Montesano, Francesco; Nichol, Robert C; Nuza, Sebastian E; Olmstead, Matthew D; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Parejko, John; Percival, Will J; Petitjean, Patrick; Prada, Francisco; Price-Whelan, Adrian M; Reid, Beth; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Sabiu, Cristiano G; Saito, Shun; Samushia, Lado; Sanchez, Ariel G; Schlegel, David J; Schneider, Donald P; Scoccola, Claudia G; Seo, Hee-Jong; Skibba, Ramin A; Strauss, Michael A; Swanson, Molly E C; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Magana, Mariana Vargas; Verde, Licia; Wake, David A; Weaver, Benjamin A; Weinberg, David H; White, Martin; Xu, Xiaoying; Yeche, Christophe; Zehavi, Idit; Zhao, Gong-Bo
2013-01-01
We present a one per cent measurement of the cosmic distance scale from the detections of the baryon acoustic oscillations in the clustering of galaxies from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey III (SDSS-III). Our results come from the Data Release 11 (DR11) sample, containing nearly one million galaxies and covering approximately 8500 square degrees and the redshift range $0.2
The Multi-Object, Fiber-Fed Spectrographs for SDSS and the Baryon Oscillation Spectroscopic Survey
Smee, Stephen; Uomoto, Alan; Roe, Natalie; Schlegel, David; Rockosi, Constance M; Carr, Michael A; Leger, French; Dawson, Kyle S; Olmstead, Matthew D; Brinkmann, Jon; Owen, Russell; Barkhouser, Robert H; Honscheid, Klaus; Harding, Paul; Long, Dan; Lupton, Robert H; Loomis, Craig; Anderson, Lauren; Annis, James; Bernardi, Mariangela; Bhardwaj, Vaishali; Bizyaev, Dmitry; Bolton, Adam S; Brewington, Howard; Briggs, John W; Burles, Scott; Burns, James G; Castander, Francisco; Connolly, Andrew; Davenport, James R; Ebelke, Garrett; Epps, Harland; Feldman, Paul D; Friedman, Scott; Frieman, Joshua; Heckman, Timothy; Hull, Charles L; Knapp, Gillian R; Lawrence, David M; Loveday, Jon; Mannery, Edward J; Malanushenko, Elena; Malanushenko, Viktor; Merrelli, Aronne; Muna, Demitri; Newman, Peter; Nichol, Robert C; Oravetz, Daniel; Pan, Kaike; Pope, Adrian C; Ricketts, Paul G; Shelden, Alaina; Sandford, Dale; Siegmund, Walter; Simmons, Audrey; Smith, D; Snedden, Stephanie; Schneider, Donald P; Strauss, Michael; SubbaRao, Mark; Tremonti, Christy; Waddell, Patrick; York, Donald G
2012-01-01
We present the design and performance of the multi-object fiber spectrographs for the Sloan Digital Sky Survey (SDSS) and their upgrade for the Baryon Oscillation Spectroscopic Survey (BOSS). Originally commissioned in Fall 1999 on the 2.5-m aperture Sloan Telescope at Apache Point Observatory, the spectrographs produced more than 1.5 million spectra for the SDSS and SDSS-II surveys, enabling a wide variety of Galactic and extra-galactic science including the first observation of baryon acoustic oscillations in 2005. The spectrographs were upgraded in 2009 and are currently in use for BOSS, the flagship survey of the third-generation SDSS-III project. BOSS will measure redshifts of 1.35 million massive galaxies to redshift 0.7 and Lyman-$\\alpha$ absorption of 160,000 high redshift quasars over 10,000 square degrees of sky, making percent level measurements of the absolute cosmic distance scale of the Universe and placing tight constraints on the equation of state of dark energy. The twin multi-object fiber sp...
Ross, Nicholas P; White, Martin; Richards, Gordon T; Myers, Adam D; Palanque-Delabrouille, Nathalie; Strauss, Michael A; Anderson, Scott F; Shen, Yue; Brandt, W N; Yeche, Christophe; Swanson, Molly E C; Aubourg, Eric; Bailey, Stephen; Bizyaev, Dmitry; Bovy, Jo; Brewington, Howard; Brinkmann, J; DeGraf, Colin; Di Matteo, Tiziana; Ebelke, Garrett; Fan, Xiaohui; Ge, Jian; Malanushenko, Elena; Malanushenko, Viktor; Mandelbaum, Rachel; Maraston, Claudia; Muna, Demitri; Oravetz, Daniel; Pan, Kaike; Paris, Isabelle; Petitjean, Patrick; Schawinski, Kevin; Schlegel, David J; Schneider, Donald P; Silverman, John D; Simmons, Audrey; Snedden, Stephanie; Streblyanska, Alina; Suzuki, Nao; Weinberg, David H; York, Donald
2012-01-01
We present a new measurement of the optical Quasar Luminosity Function (QLF), using data from the Sloan Digital Sky Survey-III: Baryon Oscillation Spectroscopic Survey (SDSS-III: BOSS). From the SDSS-III Data Release Nine (DR9), we select a uniform sample of 22,301 i<=21.8 quasars over an area of 2236 sq. deg with confirmed spectroscopic redshifts between 2.2
The SDSS-IV extended Baryonic Oscillation Spectroscopic Survey: Luminous Red Galaxy Target Selection
Prakash, Abhishek; Newman, Jeffrey A; Ross, Ashley J; Myers, Adam D; Dawson, Kyle S; Kneib, Jean-Paul; Percival, Will J; Bautista, Julian E; Comparat, Johan; Tinker, Jeremy L; Schlegel, David J; Tojeiro, Rita; Ho, Shirley; Lang, Dustin; Rao, Sandhya M; McBride, Cameron K; Zhu, Guangtun Ben; Brownstein, Joel R; Bailey, Stephen; Bolton, Adam S; Delubac, Timothee; Mariappan, Vivek; Blanton, Michael R; Reid, Beth; Schneider, Donald P; Seo, Hee-Jong; Rosell, Aurelio Carnero; Prada, Francisco
2015-01-01
We describe the algorithm used to select the Luminous Red Galaxy (LRG) sample for the extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey IV (SDSS-IV) using photometric data from both the SDSS and the Wide-Field Infrared Survey Explorer (WISE). LRG targets are required to meet a set of color selection criteria and have z-band and i-band MODEL magnitudes z < 19.95 and 19.9 < i < 21.8, respectively. Our algorithm selects roughly 50 LRG targets per square degree, the great majority of which lie in the redshift range 0.6 < z < 1.0 (median redshift 0.71). We demonstrate that our methods are highly effective at eliminating stellar contamination and lower-redshift galaxies. We perform a number of tests using spectroscopic data from SDSS-III/BOSS to determine the redshift reliability of our target selection and its ability to meet the science requirements of eBOSS. The SDSS spectra are of high enough signal-to-noise ratio that at least 89% of the target sample yield...
Beutler, Florian; Ross, Ashley J; McDonald, Patrick; Saito, Shun; Bolton, Adam S; Brownstein, Joel R; Chuang, Chia-Hsun; Cuesta, Antonio J; Eisenstein, Daniel J; Font-Ribera, Andreu; Grieb, Jan Niklas; Hand, Nick; Kitaura, Francisco-Shu; Modi, Chirag; Nichol, Robert C; Percival, Will J; Prada, Francisco; Rodriguez-Torres, Sergio; Roe, Natalie A; Ross, Nicholas P; Salazar-Albornoz, Salvador; Sánchez, Ariel G; Schneider, Donald P; Slosar, Anže; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magaña, Mariana; Vazquez, Jose A
2016-01-01
We analyse the Baryon Acoustic Oscillation (BAO) signal of the final Baryon Oscillation Spectroscopic Survey (BOSS) data release (DR12). Our analysis is performed in Fourier-space, using the power spectrum monopole and quadrupole. The dataset includes $1\\,198\\,006$ galaxies over the redshift range $0.2 < z < 0.75$. We divide this dataset into three (overlapping) redshift bins with the effective redshifts $\\zeff = 0.38$, $0.51$ and $0.61$. We demonstrate the reliability of our analysis pipeline using N-body simulations as well as $\\sim 1000$ MultiDark-Patchy mock catalogues, which mimic the BOSS-DR12 target selection. We apply density field reconstruction to enhance the BAO signal-to-noise ratio. By including the power spectrum quadrupole we can separate the line-of-sight and angular modes, which allows us to constrain the angular diameter distance $D_A(z)$ and the Hubble parameter $H(z)$ separately. We obtain two independent $1.6\\%$ and $1.5\\%$ constraints on $D_A(z)$ and $2.9\\%$ and $2.3\\%$ constraints...
Vargas-Magaña, Mariana; Cuesta, Antonio J; O'Connell, Ross; Ross, Ashley J; Eisenstein, Daniel J; Percival, Will J; Grieb, Jan Niklas; Sánchez, Ariel G; Tinker, Jeremy L; Tojeiro, Rita; Beutler, Florian; Chuang, Chia-Hsun; Kitaura, Francisco-Shu; Prada, Francisco; Rodríguez-Torres, Sergio A; Rossi, Graziano; Seo, Hee-Jong; Brownstein, Joel R; Olmstead, Matthew; Thomas, Daniel
2016-01-01
We investigate the potential sources of theoretical systematics in the anisotropic Baryon Acoustic Oscillation (BAO) distance scale measurements from the clustering of galaxies in configuration space using the final Data Release (DR12) of the Baryon Oscillation Spectroscopic Survey (BOSS). We perform a detailed study of the impact on BAO measurements from choices in the methodology such as fiducial cosmology, clustering estimators, random catalogues, fitting templates, and covariance matrices. The theoretical systematic uncertainties in BAO parameters are found to be 0.002 in in the isotropic dilation $\\alpha$ and 0.003 in in the quadrupolar dilation $\\epsilon$. We also present BAO-only distance scale constraints from the anisotropic analysis of the correlation function. Our constraints on the angular diameter distance $D_A(z)$ and the Hubble parameter $H(z)$ including both statistical and theoretical systematic uncertainties are 1.5% and 2.8% at $z_{\\rm eff}=0.38$, 1.4% and 2.4% at $z_{\\rm eff}=0.51$, and 1....
THE SDSS-IV EXTENDED BARYON OSCILLATION SPECTROSCOPIC SURVEY: OVERVIEW AND EARLY DATA
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Dawson, Kyle S.; Bautista, Julian E. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Kneib, Jean-Paul [Laboratoire dástrophysique, Ecole Polytechnique Fédérale de Lausanne Observatoire de Sauverny, 1290 Versoix (Switzerland); Percival, Will J. [Institute of Cosmology and Gravitation, Dennis Sciama Building, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Alam, Shadab [Bruce and Astrid McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA 15213 (United States); Albareti, Franco D. [Instituto de Física Teórica, (UAM/CSIC), Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Armengaud, Eric [CEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette (France); Aubourg, Éric [APC, University of Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite (France); Bailey, Stephen; Beutler, Florian [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720 (United States); Berlind, Andreas A. [Department of Physics and Astronomy, Vanderbilt University, PMB 401807, 2401 Vanderbilt Place, Nashville, TN 37240 (United States); Bershady, Matthew A. [University of Wisconsin-Madison, Department of Astronomy, 475 N. Charter St., Madison WI 53703 (United States); Bizyaev, Dmitry [Apache Point Observatory, P.O. Box 59, sunspot, NM 88349 (United States); Blanton, Michael R., E-mail: kdawson@astro.utah.edu [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); and others
2016-02-15
In a six-year program started in 2014 July, the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) will conduct novel cosmological observations using the BOSS spectrograph at Apache Point Observatory. These observations will be conducted simultaneously with the Time Domain Spectroscopic Survey (TDSS) designed for variability studies and the Spectroscopic Identification of eROSITA Sources (SPIDERS) program designed for studies of X-ray sources. In particular, eBOSS will measure with percent-level precision the distance-redshift relation with baryon acoustic oscillations (BAO) in the clustering of matter. eBOSS will use four different tracers of the underlying matter density field to vastly expand the volume covered by BOSS and map the large-scale-structures over the relatively unconstrained redshift range 0.6 < z < 2.2. Using more than 250,000 new, spectroscopically confirmed luminous red galaxies at a median redshift z = 0.72, we project that eBOSS will yield measurements of the angular diameter distance d{sub A}(z) to an accuracy of 1.2% and measurements of H(z) to 2.1% when combined with the z > 0.6 sample of BOSS galaxies. With ∼195,000 new emission line galaxy redshifts, we expect BAO measurements of d{sub A}(z) to an accuracy of 3.1% and H(z) to 4.7% at an effective redshift of z = 0.87. A sample of more than 500,000 spectroscopically confirmed quasars will provide the first BAO distance measurements over the redshift range 0.9 < z < 2.2, with expected precision of 2.8% and 4.2% on d{sub A}(z) and H(z), respectively. Finally, with 60,000 new quasars and re-observation of 60,000 BOSS quasars, we will obtain new Lyα forest measurements at redshifts z > 2.1; these new data will enhance the precision of d{sub A}(z) and H(z) at z > 2.1 by a factor of 1.44 relative to BOSS. Furthermore, eBOSS will provide improved tests of General Relativity on cosmological scales through redshift-space distortion measurements, improved tests for non
Narrow C IV absorption doublets on quasar spectra of the Baryon Oscillation Spectroscopic Survey
Chen, Zhi-Fu; Gu, Qiu-Sheng; Zhou, Luwenjia; Chen, Yan-Mei
2016-11-01
In this paper, we extend our work of Papers I and II, which are assigned to systematically survey C IV λλ1548,1551 narrow absorption lines (NALs) with zabs ≪ zem on quasar spectra of the Baryon Oscillation Spectroscopic Survey (BOSS) to collect C IV NALs with zabs ≈ zem from blue to red wings of C IV λ1549 emission lines. Together with Papers I and II, we have collected a total number of 41 479 C IV NALs with 1.4544 ≤ zabs ≤ 4.9224 in surveyed spectral region redward of Lyα until red wing of C IV λ1549 emission line. We find that the stronger C IV NALs tend to be the more saturated absorptions, and associated systems (zabs ≈ zem) seem to have larger absorption strengths when compared to intervening ones (zabs ≪ zem). The redshift density evolution behaviour of absorbers (the number of absorbers per redshift path) is similar to the history of the cosmic star formation. When compared to the quasar-frame velocity (β) distribution of Mg II absorbers, the β distribution of C IV absorbers is broader at β ≈ 0, shows longer extended tail, and exhibits a larger dispersion for environmental absorptions. In addition, for associated C IV absorbers, we find that low-luminosity quasars seem to exhibit smaller β and stronger absorptions when compared to high-luminosity quasars.
Narrow C IV absorption doublets on quasar spectra of the Baryon Oscillation Spectroscopic Survey
Zhi-fu, Chen; Luwenjia, Zhou; Yanmei, Chen
2016-01-01
In this paper, we extend our works of Papers I and II, which are assigned to systematically survey \\CIVab\\ narrow absorption lines (NALs) with \\zabs$\\ll$\\zem\\ on quasar spectra of the Baryon Oscillation Spectroscopic Survey (BOSS), to collect \\CIV\\ NALs with \\zabs$\\approx$\\zem\\ from blue to red wings of \\CIVwave\\ emission lines. Together with Papers I and II, we have collected a total number of 41,479 \\CIV\\ NALs with $1.4544\\le$\\zabs$\\le4.9224$ in surveyed spectral region redward of \\lya\\ until red wing of \\CIVwave\\ emission line. We find that the stronger \\CIV\\ NALs tend to be the more saturated absorptions, and associated systems (\\zabs$\\approx$\\zem) seem to have larger absorption strengths when compared to intervening ones (\\zabs$\\ll$\\zem). The redshift density evolution behavior of absorbers (the number of absorbers per redshift path) is similar to the history of the cosmic star formation. When compared to the quasar-frame velocity ($\\beta$) distribution of \\MgII\\ absorbers, the $\\beta$ distribution of \\C...
The extended Baryon Oscillation Spectroscopic Survey (eBOSS): a cosmological forecast
Zhao, Gong-Bo; Ross, Ashley J; Shandera, Sarah; Percival, Will J; Dawson, Kyle S; Kneib, Jean-Paul; Myers, Adam D; Brownstein, Joel R; Comparat, Johan; Delubac, Timothée; Gao, Pengyuan; Hojjati, Alireza; Koyama, Kazuya; McBride, Cameron K; Meza, Andrés; Newman, Jeffrey A; Palanque-Delabrouille, Nathalie; Pogosian, Levon; Prada, Francisco; Rossi, Graziano; Schneider, Donald P; Seo, Hee-Jong; Tao, Charling; Wang, Dandan; Yèche, Christophe; Zhang, Hanyu; Zhang, Yuecheng; Zhou, Xu; Zhu, Fangzhou; Zou, Hu
2015-01-01
We present a science forecast for the eBOSS survey, part of the SDSS-IV project, which is a spectroscopic survey using multiple tracers of large-scale structure, including luminous red galaxies (LRGs), emission line galaxies (ELGs) and quasars (both as a direct probe of structure and through the Ly-$\\alpha$ forest). Focusing on discrete tracers, we forecast the expected accuracy of the baryonic acoustic oscillation (BAO), the redshift-space distortion (RSD) measurements, the $f_{\\rm NL}$ parameter quantifying the primordial non-Gaussianity, the dark energy and modified gravity parameters. We also use the line-of-sight clustering in the Ly-$\\alpha$ forest to constrain the total neutrino mass. We find that eBOSS LRGs ($0.60.6$), ELGs ($0.6
Bolton, Adam S; Aubourg, Eric; Bailey, Stephen; Bhardwaj, Vaishali; Brownstein, Joel R; Burles, Scott; Chen, Yan-Mei; Gunn, James E; Dawson, Kyle; Eisenstein, Daniel J; Knapp, G R; Loomis, Craig P; Lupton, Robert H; Maraston, Claudia; Muna, Demitri; Myers, Adam D; Olmstead, Matthew D; Padmanabhan, Nikhil; Paris, Isabelle; Percival, Will J; Petitjean, Patrick; Rockosi, Constance M; Ross, Nicholas P; Schneider, Donald P; Shu, Yiping; Strauss, Michael A; Thomas, Daniel; Tremonti, Christy A; Wake, David A; Weaver, Benjamin A; Wood-Vasey, W Michael
2012-01-01
(abridged) We describe the automated spectral classification, redshift determination, and parameter measurement pipeline in use for the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III (SDSS-III) as of Data Release 9, encompassing 831,000 moderate-resolution optical spectra. We give a review of the algorithms employed, and describe the changes to the pipeline that have been implemented for BOSS relative to previous SDSS-I/II versions, including new sets of stellar, galaxy, and quasar redshift templates. For the color-selected CMASS sample of massive galaxies at redshift 0.4 <~ z <~ 0.8 targeted by BOSS for the purposes of large-scale cosmological measurements, the pipeline achieves an automated classification success rate of 98.7% and confirms 95.4% of unique CMASS targets as galaxies (with the balance being mostly M stars). Based on visual inspections of a subset of BOSS galaxies, we find that ~0.2% of confidently reported CMASS sample classifications and redshifts are...
Bolton, Adam S.; Schlegel, David J.; Aubourg, Éric; Bailey, Stephen; Bhardwaj, Vaishali; Brownstein, Joel R.; Burles, Scott; Chen, Yan-Mei; Dawson, Kyle; Eisenstein, Daniel J.; Gunn, James E.; Knapp, G. R.; Loomis, Craig P.; Lupton, Robert H.; Maraston, Claudia; Muna, Demitri; Myers, Adam D.; Olmstead, Matthew D.; Padmanabhan, Nikhil; Pâris, Isabelle; Percival, Will J.; Petitjean, Patrick; Rockosi, Constance M.; Ross, Nicholas P.; Schneider, Donald P.; Shu, Yiping; Strauss, Michael A.; Thomas, Daniel; Tremonti, Christy A.; Wake, David A.; Weaver, Benjamin A.; Wood-Vasey, W. Michael
2012-11-01
We describe the automated spectral classification, redshift determination, and parameter measurement pipeline in use for the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III (SDSS-III) as of the survey's ninth data release (DR9), encompassing 831,000 moderate-resolution optical spectra. We give a review of the algorithms employed, and describe the changes to the pipeline that have been implemented for BOSS relative to previous SDSS-I/II versions, including new sets of stellar, galaxy, and quasar redshift templates. For the color-selected "CMASS" sample of massive galaxies at redshift 0.4 visual inspections of a subset of BOSS galaxies, we find that approximately 0.2% of confidently reported CMASS sample classifications and redshifts are incorrect, and about 0.4% of all CMASS spectra are objects unclassified by the current algorithm which are potentially recoverable. The BOSS pipeline confirms that ~51.5% of the quasar targets have quasar spectra, with the balance mainly consisting of stars and low signal-to-noise spectra. Statistical (as opposed to systematic) redshift errors propagated from photon noise are typically a few tens of km s-1 for both galaxies and quasars, with a significant tail to a few hundreds of km s-1 for quasars. We test the accuracy of these statistical redshift error estimates using repeat observations, finding them underestimated by a factor of 1.19-1.34 for galaxies and by a factor of two for quasars. We assess the impact of sky-subtraction quality, signal-to-noise ratio, and other factors on galaxy redshift success. Finally, we document known issues with the BOSS DR9 spectroscopic data set and describe directions of ongoing development.
Beutler, Florian; Seo, Hee-Jong; Ross, Ashley J.; McDonald, Patrick; Saito, Shun; Bolton, Adam S.; Brownstein, Joel R.; Chuang, Chia-Hsun; Cuesta, Antonio J.; Eisenstein, Daniel J.; Font-Ribera, Andreu; Grieb, Jan Niklas; Hand, Nick; Kitaura, Francisco-Shu; Modi, Chirag; Nichol, Robert C.; Percival, Will J.; Prada, Francisco; Rodriguez-Torres, Sergio; Roe, Natalie A.; Ross, Nicholas P.; Salazar-Albornoz, Salvador; Sánchez, Ariel G.; Schneider, Donald P.; Slosar, Anže; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magaña, Mariana; Vazquez, Jose A.
2017-01-01
We analyse the baryon acoustic oscillation (BAO) signal of the final Baryon Oscillation Spectroscopic Survey (BOSS) data release (DR12). Our analysis is performed in the Fourier space, using the power spectrum monopole and quadrupole. The data set includes 1198 006 galaxies over the redshift range 0.2 < z < 0.75. We divide this data set into three (overlapping) redshift bins with the effective redshifts zeff = 0.38, 0.51 and 0.61. We demonstrate the reliability of our analysis pipeline using N-body simulations as well as ˜1000 MultiDark-Patchy mock catalogues that mimic the BOSS-DR12 target selection. We apply density field reconstruction to enhance the BAO signal-to-noise ratio. By including the power spectrum quadrupole we can separate the line of sight and angular modes, which allows us to constrain the angular diameter distance DA(z) and the Hubble parameter H(z) separately. We obtain two independent 1.6 and 1.5 per cent constraints on DA(z) and 2.9 and 2.3 per cent constraints on H(z) for the low (zeff = 0.38) and high (zeff = 0.61) redshift bin, respectively. We obtain two independent 1 and 0.9 per cent constraints on the angular averaged distance DV(z), when ignoring the Alcock-Paczynski effect. The detection significance of the BAO signal is of the order of 8σ (post-reconstruction) for each of the three redshift bins. Our results are in good agreement with the Planck prediction within Λ cold dark matter. This paper is part of a set that analyses the final galaxy clustering data set from BOSS. The measurements and likelihoods presented here are combined with others in Alam et al. to produce the final cosmological constraints from BOSS.
Sanchez, Ariel G; Salazar-Albornoz, Salvador; Alam, Shadab; Beutler, Florian; Ross, Ashley J; Brownstein, Joel R; Chuang, Chia-Hsun; Cuesta, Antonio J; Eisenstein, Daniel J; Kitaura, Francisco-Shu; Percival, Will J; Prada, Francisco; Rodriguez-Torres, Sergio; Seo, Hee-Jong; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magana, Mariana; Vazquez, Jose A; Zhao, Gong-Bo
2016-01-01
The cosmological information contained in anisotropic galaxy clustering measurements can often be compressed into a small number of parameters whose posterior distribution is well described by a Gaussian. We present a general methodology to combine these estimates into a single set of consensus constraints that encode the total information of the individual measurements, taking into account the full covariance between the different methods. We illustrate this technique by applying it to combine the results obtained from different clustering analyses, including measurements of the signature of baryon acoustic oscillations (BAO) and redshift-space distortions (RSD), based on a set of mock catalogues of the final SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). Our results show that the region of the parameter space allowed by the consensus constraints is smaller than that of the individual methods, highlighting the importance of performing multiple analyses on galaxy surveys even when the measurements a...
Ross, Ashley J.; Beutler, Florian; Chuang, Chia-Hsun; Pellejero-Ibanez, Marcos; Seo, Hee-Jong; Vargas-Magaña, Mariana; Cuesta, Antonio J.; Percival, Will J.; Burden, Angela; Sánchez, Ariel G.; Grieb, Jan Niklas; Reid, Beth; Brownstein, Joel R.; Dawson, Kyle S.; Eisenstein, Daniel J.; Ho, Shirley; Kitaura, Francisco-Shu; Nichol, Robert C.; Olmstead, Matthew D.; Prada, Francisco; Rodríguez-Torres, Sergio A.; Saito, Shun; Salazar-Albornoz, Salvador; Schneider, Donald P.; Thomas, Daniel; Tinker, Jeremy; Tojeiro, Rita; Wang, Yuting; White, Martin; Zhao, Gong-bo
2017-01-01
We present baryon acoustic oscillation (BAO) scale measurements determined from the clustering of 1.2 million massive galaxies with redshifts 0.2 image quality and Galactic extinction, and weights to account for density relationships intrinsic to the imaging and spectroscopic portions of the survey. We simulate the observed systematic trends in mock galaxy samples and demonstrate that they impart no bias on BAO scale measurements and have a minor impact on the recovered statistical uncertainty. We measure transverse and radial BAO distance measurements in 0.2 < z < 0.5, 0.5 < z < 0.75, and (overlapping) 0.4 < z < 0.6 redshift bins. In each redshift bin, we obtain a precision that is 2.7 per cent or better on the radial distance and 1.6 per cent or better on the transverse distance. The combination of the redshift bins represents 1.8 per cent precision on the radial distance and 1.1 per cent precision on the transverse distance. This paper is part of a set that analyses the final galaxy clustering data set from BOSS. The measurements and likelihoods presented here are combined with others in Alam et al. to produce the final cosmological constraints from BOSS.
Raichoor, A; Delubac, T; Kneib, J -P; Yèche, C; Zou, H; Abdalla, F B; Dawson, K; Fan, X; Fan, Z; Jiang, Z; Jing, Y; Jouvel, S; Lang, D; Lesser, M; Li, C; Ma, J; Newman, J A; Nie, J; Olszewski, E; Palanque-Delabrouille, N; Percival, W; Prada, F; Shen, S; Wang, J; Wu, Z; Zhang, T; Zhou, X; Zhou, Z
2015-01-01
We present a new selection technique to produce spectroscopic target catalogues for massive spectroscopic surveys for cosmology. This work was conducted in the context of the extended Baryon Oscillation Spectroscopic Survey (eBOSS), which will use 200,000 emission line galaxies (ELGs) at 0.6
Hernández-Monteagudo, Carlos; Ross, Ashley J.; Cuesta, Antonio; Génova-Santos, Ricardo; Xia, Jun-Qing; Prada, Francisco; Rossi, Graziano; Neyrinck, Mark; Viel, Matteo; Rubiño-Martin, Jose-Alberto; Scóccola, Claudia G.; Zhao, Gongbo; Schneider, Donald P.; Brownstein, Joel R.; Thomas, Daniel; Brinkmann, Jonathan V.
2014-02-01
In the context of the study of the integrated Sachs-Wolfe (ISW) effect, we construct a template of the projected density distribution up to redshift z ≃ 0.7 by using the luminous galaxies (LGs) from the Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8). We use a photometric redshift catalogue trained with more than a hundred thousand galaxies from the Baryon Oscillation Spectroscopic Survey (BOSS) in the SDSS DR8 imaging area covering nearly one-quarter of the sky. We consider two different LG samples whose selection matches that of SDSS-III/BOSS: the low-redshift sample (LOWZ, z ∈ [0.15, 0.5]) and the constant mass sample (CMASS, z ∈ [0.4, 0.7]). When building the galaxy angular density templates we use the information from star density, survey footprint, seeing conditions, sky emission, dust extinction and airmass to explore the impact of these artefacts on each of the two LG samples. In agreement with previous studies, we find that the CMASS sample is particularly sensitive to Galactic stars, which dominate the contribution to the auto-angular power spectrum below ℓ = 7. Other potential systematics affect mostly the very low multipole range (ℓ ∈ [2, 7]), but leave fluctuations on smaller scales practically unchanged. The resulting angular power spectra in the multipole range ℓ ∈ [2, 100] for the LOWZ, CMASS and LOWZ+CMASS samples are compatible with linear Λ cold dark matter (ΛCDM) expectations and constant bias values of b = 1.98 ± 0.11, 2.08 ± 0.14 and 1.88 ± 0.11, respectively, with no traces of non-Gaussianity signatures, i.e. f_NL^local=59± 75 at 95 per cent confidence level for the full LOWZ+CMASS sample in the multipole range ℓ ∈ [4, 100]. After cross-correlating Wilkinson Microwave Anisotropy Probe 9-year data with the LOWZ+CMASS LG projected density field, the ISW signal is detected at the level of 1.62-1.69σ. While this result is in close agreement with theoretical expectations and predictions from realistic Monte Carlo
Raichoor, A.; Comparat, J.; Delubac, T.; Kneib, J.-P.; Yèche, Ch.; Zou, H.; Abdalla, F. B.; Dawson, K.; de la Macorra, A.; Fan, X.; Fan, Z.; Jiang, Z.; Jing, Y.; Jouvel, S.; Lang, D.; Lesser, M.; Li, C.; Ma, J.; Newman, J. A.; Nie, J.; Palanque-Delabrouille, N.; Percival, W. J.; Prada, F.; Shen, S.; Wang, J.; Wu, Z.; Zhang, T.; Zhou, X.; Zhou, Z.
2016-01-01
We present a new selection technique of producing spectroscopic target catalogues for massive spectroscopic surveys for cosmology. This work was conducted in the context of the extended Baryon Oscillation Spectroscopic Survey (eBOSS), which will use ~200 000 emission line galaxies (ELGs) at 0.6 ≤ zspec ≤ 1.0 to obtain a precise baryon acoustic oscillation measurement. Our proposed selection technique is based on optical and near-infrared broad-band filter photometry. We used a training sample to define a quantity, the Fisher discriminant (linear combination of colours), which correlates best with the desired properties of the target: redshift and [Oii] flux. The proposed selections are simply done by applying a cut on magnitudes and this Fisher discriminant. We used public data and dedicated SDSS spectroscopy to quantify the redshift distribution and [Oii] flux of our ELG target selections. We demonstrate that two of our selections fulfil the initial eBOSS/ELG redshift requirements: for a target density of 180 deg-2, ~70% of the selected objects have 0.6 ≤ zspec ≤ 1.0 and only ~1% of those galaxies in the range 0.6 ≤ zspec ≤ 1.0 are expected to have a catastrophic zspec estimate. Additionally, the stacked spectra and stacked deep images for those two selections show characteristic features of star-forming galaxies. The proposed approach using the Fisher discriminant could, however, be used to efficiently select other galaxy populations, based on multi-band photometry, providing that spectroscopic information isavailable. This technique could thus be useful for other future massive spectroscopic surveys such as PFS, DESI, and 4MOST.
Reid, Beth; Padmanabhan, Nikhil; Percival, Will J; Tinker, Jeremy; Tojeiro, Rita; White, Martin; Eisenstein, Daniel J; Maraston, Claudia; Ross, Ashley J; Sanchez, Ariel G; Schlegel, David; Sheldon, Erin; Strauss, Michael A; Thomas, Daniel; Wake, David; Beutler, Florian; Bizyaev, Dmitry; Bolton, Adam S; Brownstein, Joel R; Chuang, Chia-Hsun; Dawson, Kyle; Harding, Paul; Kitaura, Francisco-Shu; Leauthaud, Alexie; Masters, Karen; McBride, Cameron K; More, Surhud; Olmstead, Matthew D; Oravetz, Daniel; Nuza, Sebastian E; Pan, Kaike; Parejko, John; Pforr, Janine; Prada, Francisco; Rodriguez-Torres, Sergio; Salazar-Albornoz, Salvador; Samushia, Lado; Schneider, Donald P; Scoccola, Claudia G; Simmons, Audrey; Vargas-Magana, Mariana
2015-01-01
The Baryon Oscillation Spectroscopic Survey (BOSS), part of the Sloan Digital Sky Survey (SDSS) III project, has provided the largest survey of galaxy redshifts available to date, in terms of both the number of galaxy redshifts measured by a single survey, and the effective cosmological volume covered. Key to analysing the clustering of these data to provide cosmological measurements is understanding the detailed properties of this sample. Potential issues include variations in the target catalogue caused by changes either in the targeting algorithm or properties of the data used, the pattern of spectroscopic observations, the spatial distribution of targets for which redshifts were not obtained, and variations in the target sky density due to observational systematics. We document here the target selection algorithms used to create the galaxy samples that comprise BOSS. We also present the algorithms used to create large scale structure catalogues for the final Data Release (DR12) samples and the associated ...
Beutler, Florian; Seo, Hee-Jong; Saito, Shun; Chuang, Chia-Hsun; Cuesta, Antonio J.; Eisenstein, Daniel J.; Gil-Marín, Héctor; Grieb, Jan Niklas; Hand, Nick; Kitaura, Francisco-Shu; Modi, Chirag; Nichol, Robert C.; Olmstead, Matthew D.; Percival, Will J.; Prada, Francisco; Sánchez, Ariel G.; Rodriguez-Torres, Sergio; Ross, Ashley J.; Ross, Nicholas P.; Schneider, Donald P.; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magaña, Mariana
2017-04-01
We investigate the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 sample, which consists of 1198 006 galaxies in the redshift range 0.2 measure redshift-space distortions simultaneously with the Alcock-Paczynski effect and the baryon acoustic oscillation scale. We include the power-spectrum monopole, quadrupole and hexadecapole in our analysis and compare our measurements with a perturbation-theory-based model, while properly accounting for the survey window function. To evaluate the reliability of our analysis pipeline, we participate in a mock challenge, which results in systematic uncertainties significantly smaller than the statistical uncertainties. While the high-redshift constraint on fσ8 at zeff = 0.61 indicates a small (∼1.4σ) deviation from the prediction of the Planck ΛCDM (Λ cold dark matter) model, the low-redshift constraint is in good agreement with Planck ΛCDM. This paper is part of a set that analyses the final galaxy clustering data set from BOSS. The measurements and likelihoods presented here are combined with others in Alam et al. to produce the final cosmological constraints from BOSS.
Sánchez, Ariel G.; Grieb, Jan Niklas; Salazar-Albornoz, Salvador; Alam, Shadab; Beutler, Florian; Ross, Ashley J.; Brownstein, Joel R.; Chuang, Chia-Hsun; Cuesta, Antonio J.; Eisenstein, Daniel J.; Kitaura, Francisco-Shu; Percival, Will J.; Prada, Francisco; Rodríguez-Torres, Sergio; Seo, Hee-Jong; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magaña, Mariana; Vazquez, Jose A.; Zhao, Gong-Bo
2017-01-01
The cosmological information contained in anisotropic galaxy clustering measurements can often be compressed into a small number of parameters whose posterior distribution is well described by a Gaussian. We present a general methodology to combine these estimates into a single set of consensus constraints that encode the total information of the individual measurements, taking into account the full covariance between the different methods. We illustrate this technique by applying it to combine the results obtained from different clustering analyses, including measurements of the signature of baryon acoustic oscillations and redshift-space distortions, based on a set of mock catalogues of the final SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). Our results show that the region of the parameter space allowed by the consensus constraints is smaller than that of the individual methods, highlighting the importance of performing multiple analyses on galaxy surveys even when the measurements are highly correlated. This paper is part of a set that analyses the final galaxy clustering data set from BOSS. The methodology presented here is used in Alam et al. to produce the final cosmological constraints from BOSS.
Bautista, Julian E; Font-Ribera, Andreu; Pieri, Matthew M; Busca, Nicolás G; Miralda-Escudé, Jordi; Palanque-Delabrouille, Nathalie; Rich, James; Dawson, Kyle; Feng, Yu; Ge, Jian; Gontcho, Satya Gontcho A; Ho, Shirley; Goff, Jean Marc Le; Noterdaeme, Pasquier; Pâris, Isabelle; Rossi, Graziano; Schlegel, David
2014-01-01
We describe mock data-sets generated to simulate the high-redshift quasar sample in Data Release 11 (DR11) of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). The mock spectra contain Ly{\\alpha} forest correlations useful for studying the 3D correlation function including Baryon Acoustic Oscillations (BAO). They also include astrophysical effects such as quasar continuum diversity and high-density absorbers, instrumental effects such as noise and spectral resolution, as well as imperfections introduced by the SDSS pipeline treatment of the raw data. The Ly{\\alpha} forest BAO analysis of the BOSS collaboration, described in Delubac et al. 2014, has used these mock data-sets to develop and cross-check analysis procedures prior to performing the BAO analysis on real data, and for continued systematic cross checks. Tests presented here show that the simulations reproduce sufficiently well important characteristics of real spectra. These mock data-sets will be made available together with the data at t...
Ross, Ashley J; Sanchez, Ariel G; Samushia, Lado; Ho, Shirley; Kazin, Eyal; Manera, Marc; Reid, Beth; White, Martin; Tojeiro, Rita; McBride, Cameron K; Xu, Xiaoying; Wake, David A; Strauss, Michael A; Montesano, Francesco; Swanson, Molly E C; Bailey, Stephen; Bolton, Adam S; Dorta, Antonio Montero; Eisenstein, Daniel J; Guo, Hong; Hamilton, Jean-Christophe; Nichol, Robert C; Padmanabhan, Nikhil; Prada, Francisco; Schlegel, David J; Magana, Mariana Vargas; Zehavi, Idit; Blanton, Michael; Bizyaev, Dmitry; Brewington, Howard; Cuesta, Antonio J; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Parejko, John; Pan, Kaike; Shelden, Donald P Schneider Alaina; Simmons, Audrey; Snedden, Stephanie; Zhao, Gong-bo
2012-01-01
We analyze the density field of galaxies observed by the Sloan Digital Sky Survey (SDSS)-III Baryon Oscillation Spectroscopic Survey (BOSS) included in the SDSS Data Release Nine (DR9). DR9 includes spectroscopic redshifts for over 400,000 galaxies spread over a footprint of 3,275 deg^2. We identify, characterize, and mitigate the impact of sources of systematic uncertainty on large-scale clustering measurements, both for angular moments of the redshift-space correlation function and the spherically averaged power spectrum, P(k), in order to ensure that robust cosmological constraints will be obtained from these data. A correlation between the projected density of stars and the higher redshift (0.43 120h^-1Mpc or k < 0.01hMpc^-1. We find that these errors can be ameliorated by weighting galaxies based on their surface brightness and the local stellar density. We use mock galaxy catalogs that simulate the CMASS selection function to determine that randomly selecting galaxy redshifts in order to simulate th...
Guo, Hong; Zheng, Zheng; Weinberg, David H; Berlind, Andreas A; Blanton, Michael; Chen, Yanmei; Eisenstein, Daniel J; Ho, Shirley; Kazin, Eyal; Manera, Marc; Maraston, Claudia; McBride, Cameron K; Nuza, Sebastian E; Padmanabhan, Nikhil; Parejko, John K; Percival, Will J; Ross, Ashley J; Ross, Nicholas P; Samushia, Lado; Sanchez, Ariel G; Schlegel, David J; Schneider, Donald P; Skibba, Ramin A; Swanson, Molly E C; Tinker, Jeremy L; Tojeiro, Rita; Wake, David A; White, Martin; Bahcall, Neta A; Bizyaev, Dmitry; Brewington, Howard; Bundy, Kevin; da Costa, Luiz N A; Ebelke, Garrett; Malanushenko, Viktor; Malanushenko, Elena; Oravetz, Daniel; Rossi, Graziano; Simmons, Audrey; Snedden, Stephanie; Streblyanska, Alina; Thomas, Daniel
2012-01-01
We measure the luminosity and color dependence and the redshift evolution of galaxy clustering in the Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey Ninth Data Release. We focus on the projected two-point correlation function (2PCF) of subsets of its CMASS sample, which includes about 260,000 galaxies over ~3,300 sq. deg in the redshift range 0.43
Shekoyan, V.; Dehipawala, S.; Liu, Ernest; Tulsee, Vivek; Armendariz, R.; Tremberger, G.; Holden, T.; Marchese, P.; Cheung, T.
2012-10-01
Digital solar image data is available to users with access to standard, mass-market software. Many scientific projects utilize the Flexible Image Transport System (FITS) format, which requires specialized software typically used in astrophysical research. Data in the FITS format includes photometric and spatial calibration information, which may not be useful to researchers working with self-calibrated, comparative approaches. This project examines the advantages of using mass-market software with readily downloadable image data from the Solar Dynamics Observatory for comparative analysis over with the use of specialized software capable of reading data in the FITS format. Comparative analyses of brightness statistics that describe the solar disk in the study of magnetic energy using algorithms included in mass-market software have been shown to give results similar to analyses using FITS data. The entanglement of magnetic energy associated with solar eruptions, as well as the development of such eruptions, has been characterized successfully using mass-market software. The proposed algorithm would help to establish a publicly accessible, computing network that could assist in exploratory studies of all FITS data. The advances in computer, cell phone and tablet technology could incorporate such an approach readily for the enhancement of high school and first-year college space weather education on a global scale. Application to ground based data such as that contained in the Baryon Oscillation Spectroscopic Survey is discussed.
Alam, Shadab; Vargas-Magaña, Mariana; Schneider, Donald P
2015-01-01
The measured redshift ($z$) of an astronomical object is a combination of Hubble recession, gravitational redshift and peculiar velocity. In particular, the line of sight distance to a galaxy inferred from redshift is affected by the peculiar velocity component of galaxy redshift, which can also be observed as an anisotropy in the correlation function. This anisotropy allows us to measure the linear growth rate of matter ($f\\sigma_8$). In this paper, we measure the linear growth rate of matter ($f\\sigma_8$) at $z=0.57$ using the CMASS sample from Data Release 11 of Sloan Digital Sky Survey III (SDSS III) Baryon Oscillations Spectroscopic Survey (BOSS). The galaxy sample consists of 690,826 Luminous Red Galaxies (LRGs) in the redshift range 0.43 to 0.7 covering 8498 deg$^2$. Here we report the first measurement of $f\\sigma_8$ and cosmology using Convolution Lagrangian Perturbation Theory (CLPT) with Gaussian streaming model (GSRSD). We arrive at a constraint of $f\\sigma_8=0.462\\pm0.041$ (9\\% accuracy) at effec...
Chiang, Chi-Ting; Sánchez, Ariel G; Schmidt, Fabian; Komatsu, Eiichiro
2015-01-01
We report on the first measurement of the position-dependent correlation function from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 10 CMASS sample. This new observable measures the correlation between two-point functions of galaxy pairs within different subvolumes, $\\hat{\\xi}({\\rm r},{\\rm r}_L)$, where ${\\rm r}_L$ is the location of a subvolume, and the corresponding mean overdensities, $\\bar{\\delta}({\\rm r}_L)$. This correlation, which we call the "integrated three-point function", $i\\zeta(r)=\\langle\\hat{\\xi}({\\rm r},{\\rm r}_L)\\bar{\\delta}({\\rm r}_L)\\rangle$, measures a three-point function of two short- and one long-wavelength modes, and is generated by nonlinear gravitational evolution and possibly also by the physics of inflation. The $i\\zeta(r)$ measured from the BOSS data lies within the scatter of those from the mock galaxy catalogs in redshift space, yielding a ten-percent-level determination of the amplitude of $i\\zeta(r)$. The tree-level perturbation theory in redshift s...
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Ahn, Christopher P.; Anderton, Timothy [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Alexandroff, Rachael; Blake, Cullen H. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Allende Prieto, Carlos [Instituto de Astrofisica de Canarias (IAC), C/Via Lactea, s/n, E-38200 La Laguna, Tenerife (Spain); Anderson, Scott F.; Barnes, Rory; Bhardwaj, Vaishali; Bochanski, John J. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Andrews, Brett H. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Aubourg, Eric; Bautista, Julian [APC, University of Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite, F-75205 Paris (France); Bailey, Stephen [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720 (United States); Balbinot, Eduardo [Instituto de Fisica, UFRGS, Caixa Postal 15051, Porto Alegre, RS-91501-970 (Brazil); Beers, Timothy C. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Beifiori, Alessandra [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Berlind, Andreas A. [Department of Physics and Astronomy, Vanderbilt University, VU Station 1807, Nashville, TN 37235 (United States); Bizyaev, Dmitry [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Blanton, Michael R. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Blomqvist, Michael [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); and others
2012-12-15
The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z {approx} 0.52), 102,100 new quasar spectra (median z {approx} 2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T{sub eff} < 5000 K and in metallicity estimates for stars with [Fe/H] > -0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SEGUE-2. The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the APOGEE along with another year of data from BOSS, followed by the final SDSS-III data release in 2014 December.
Ahn, Christopher P; Prieto, Carlos Allende; Anderson, Scott F; Anderton, Timothy; Andrews, Brett H; Bailey, Éric Aubourg Stephen; Barnes, Rory; Bautista, Julian; Beers, Timothy C; Beifiori, Alessandra; Berlind, Andreas A; Bhardwaj, Vaishali; Bizyaev, Dmitry; Blake, Cullen H; Blanton, Michael R; Blomqvist, Michael; Bochanski, John J; Bolton, Adam S; Borde, Arnaud; Bovy, Jo; Brandt, W N; Brinkmann, J; Brown, Peter J; Brownstein, Joel R; Bundy, Kevin; Busca, N G; Carithers, William; Carnero, Aurelio R; Carr, Michael A; Casetti-Dinescu, Dana I; Chen, Yanmei; Chiappini, Cristina; Comparat, Johan; Connolly, Natalia; Crepp, Justin R; Cristiani, Stefano; Croft, Rupert A C; Cuesta, Antonio J; da Costa, Luiz N; Davenport, James R A; Dawson, Kyle S; de Putter, Roland; De Lee, Nathan; Delubac, Timothée; Dhital, Saurav; Ealet, Anne; Ebelke, Garrett L; Edmondson, Edward M; Eisenstein, Daniel J; Escoffier, S; Esposito, Massimiliano; Evans, Michael L; Fan, Xiaohui; Castellá, Bruno Femení a; Alvar, Emma Fernández; Ferreira, Leticia D; Ak, N Filiz; Finley, Hayley; Fleming, Scott W; Font-Ribera, Andreu; Frinchaboy, Peter M; García-Hernández, D A; Pérez, A E García; Ge, Jian; Génova-Santos, R; Gillespie, Bruce A; Girardi, Léo; Hernández, Jonay I González; Grebel, Eva K; Gunn, James E; Haggard, Daryl; Hamilton, Jean-Christophe; Harris, David W; Hawley, Suzanne L; Hearty, Frederick R; Ho, Shirley; Hogg, David W; Holtzman, Jon A; Honscheid, Klaus; Huehnerhoff, J; Ivans, Inese I; Ivezić, Zeljko; Jacobson, Heather R; Jiang, Linhua; Johansson, Jonas; Johnson, Jennifer A; Kauffmann, Guinevere; Kirkby, David; Kirkpatrick, Jessica A; Klaene, Mark A; Knapp, Gillian R; Kneib, Jean-Paul; Goff, Jean-Marc Le; Leauthaud, Alexie; Lee, Khee-Gan; Lee, Young Sun; Long, Daniel C; Loomis, Craig P; Lucatello, Sara; Lundgren, Britt; Lupton, Robert H; Ma, Bo; Ma, Zhibo; MacDonald, Nicholas; Mahadevan, Suvrath; Maia, Marcio A G; Majewski, Steven R; Makler, Martin; Malanushenko, Elena; Malanushenko, Viktor; Manchado, A; Mandelbaum, Rachel; Manera, Marc; Maraston, Claudia; Margala, Daniel; Martell, Sarah L; McBride, Cameron K; McGreer, Ian D; McMahon, Richard G; Ménard, Brice; Meszaros, Sz; Miralda-Escudé, Jordi; Montero-Dorta, Antonio D; Montesano, Francesco; Morrison, Heather L; Muna, Demitri; Munn, Jeffrey A; Murayama, Hitoshi; Myers, Adam D; Neto, A F; Nguyen, Duy Cuong; Nichol, Robert C; Nidever, David L; Noterdaeme, Pasquier; Ogando, Ricardo L C; Olmstead, Matthew D; Oravetz, Daniel J; Owen, Russell; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John K; Parihar, Prachi; Pâris, Isabelle; Pattarakijwanich, Petchara; Pepper, Joshua; Percival, Will J; Pérez-Fournon, Ismael; Pérez-Ráfols, Ignasi; Petitjean, Patrick; Pforr, Janine; Pieri, Matthew M; Pinsonneault, Marc H; de Mello, G F Porto; Prada, Francisco; Price-Whelan, Adrian M; Raddick, M Jordan; Rebolo, Rafael; Rich, James; Richards, Gordon T; Robin, Annie C; Rocha-Pinto, Helio J; Rockosi, Constance M; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Rubiño-Martin, J A; Samushia, Lado; Almeida, J Sanchez; Sánchez, Ariel G; Santiago, Basílio; Sayres, Conor; Schlegel, David J; Schlesinger, Katharine J; Schmidt, Sarah J; Schneider, Donald P; Schwope, Axel D; Scóccola, C G; Seljak, Uros; Sheldon, Erin; Shen, Yue; Shu, Yiping; Simmerer, Jennifer; Simmons, Audrey E; Skibba, Ramin A; Slosar, A; Sobreira, Flavia; Sobeck, Jennifer S; Stassun, Keivan G; Steele, Oliver; Steinmetz, Matthias; Strauss, Michael A; Swanson, Molly E C; Tal, Tomer; Thakar, Aniruddha R; Thomas, Daniel; Thompson, Benjamin A; Tinker, Jeremy L; Tojeiro, Rita; Tremonti, Christy A; Magaña, M Vargas; Verde, Licia; Viel, Matteo; Vikas, Shailendra K; Vogt, Nicole P; Wake, David A; Wang, Ji; Weaver, Benjamin A; Weinberg, David H; Weiner, Benjamin J; West, Andrew A; White, Martin; Wilson, John C; Wisniewski, John P; Wood-Vasey, W M; Yanny, Brian; Yèche, Christophe; York, Donald G; Zamora, O; Zasowski, Gail; Zehavi, Idit; Zhao, Gong-Bo; Zheng, Zheng; Zhu, Guangtun; Zinn, Joel C
2012-01-01
The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has...
Cuesta, Antonio J; Beutler, Florian; Bolton, Adam S; Brownstein, Joel R; Eisenstein, Daniel J; Gil-Marín, Héctor; Ho, Shirley; McBride, Cameron K; Maraston, Claudia; Padmanabhan, Nikhil; Percival, Will J; Reid, Beth A; Ross, Ashley J; Ross, Nicholas P; Sánchez, Ariel G; Schlegel, David J; Schneider, Donald P; Thomas, Daniel; Tinker, Jeremy; Tojeiro, Rita; Verde, Licia; White, Martin
2015-01-01
We present distance scale measurements from the baryon acoustic oscillation signal in the CMASS and LOWZ samples from the Data Release 12 of the Baryon Oscillation Spectroscopic Survey (BOSS). The total volume probed is 14.5 Gpc$^3$, a 10% increment from Data Release 11. From an analysis of the spherically averaged correlation function, we infer a distance to $z=0.57$ of $D_V(z)r^{\\rm fid}_{\\rm d}/r_ {\\rm d}=2028\\pm19$ Mpc and a distance to $z=0.32$ of $D_V(z)r^{\\rm fid}_{\\rm d}/r_{\\rm d}=1263\\pm21$ Mpc assuming a cosmology in which $r^{\\rm fid}_{\\rm d}=147.10$ Mpc. From the anisotropic analysis, we find an angular diameter distance to $z=0.57$ of $D_{\\rm A}(z)r^{\\rm fid}_{\\rm d}/r_{\\rm d}=1401\\pm19$ Mpc and a distance to $z=0.32$ of $981\\pm20$ Mpc, a 1.4% and 2.0% measurement respectively. The Hubble parameter at $z=0.57$ is $H(z)r_{\\rm d}/r^{\\rm fid}_{\\rm d}=100.3\\pm3.4$ km s$^{-1}$ Mpc$^{-1}$ and its value at $z=0.32$ is $79.2\\pm5.5$ km s$^{-1}$ Mpc$^{-1}$, a 3.4% and 6.9% measurement respectively. These c...
Prakash, Abhishek; SDSS-IV/eBOSS
2017-01-01
SDSS-IV/eBOSS survey will allow a ˜1% measurement of the Baryon Acoustic Oscillation (BAO) scale and a 4.0%Redshift Space Distortion (RSD) measurement using a relatively uniform set of luminous, early-type galaxies in the redshift range 0.6 image both wider areas and deeper volumes than would be possible with spectroscopy, allowing one to probe both larger scales and larger volumes. The ability to make precise clustering measurements with photometric data has been well demonstrated by Padmanabhan et al. (2007).
Ross, Ashley J; Burden, Angela; Percival, Will J; Tojeiro, Rita; Manera, Marc; Beutler, Florian; Brinkmann, J; Brownstein, Joel R; Carnero, Aurelio; da Costa, Luiz A N; Eisenstein, Daniel J; Guo, Hong; Ho, Shirley; Maia, Marcio A G; Montesano, Francesco; Muna, Demitri; Nichol, Robert C; Nuza, Sebastian E; Sanchez, Ariel G; Schneider, Donald P; Skibba, Ramin A; Sobreira, Flavia; Streblyanska, Alina; Swanson, Molly E C; Thomas, Daniel; Tinker, Jeremy L; Wake, David A; Zehavi, Idit; Zhao, Gong-bo
2013-01-01
We study the clustering of galaxies, as a function of their colour, from Data Release Ten (DR10) of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). We select 122,967 galaxies with 0.43 < z < 0.7 into a "Blue" sample and 131,969 into a "Red" sample based on k+e corrected (to z=0.55) r-i colours and i band magnitudes. The samples are chosen to each contain more than 100,000 galaxies, have similar redshift distributions, and maximize the difference in clustering amplitude. The Red sample has a 40% larger bias than the Blue (b_Red/b_Blue = 1.39+-0.04), implying the Red galaxies occupy dark matter halos with an average mass that is 0.5 log Mo greater. Spherically averaged measurements of the correlation function, \\xi 0, and the power spectrum are used to locate the position of the baryon acoustic oscillation (BAO) feature of both samples. Using \\xi 0, we obtain distance scales, relative to our reference LCDM cosmology, of 1.010+-0.027 for the Red sample and 1.005+-0.031 for the Blue. After apply...
Zhao, Gong-Bo; Saito, Shun; Wang, Dandan; Ross, Ashley J; Beutler, Florian; Grieb, Jan Niklas; Chuang, Chia-Hsun; Kitaura, Francisco-Shu; Rodriguez-Torres, Sergio; Percival, Will J; Brownstein, Joel R; Cuesta, Antonio J; Eisenstein, Daniel J; Gil-Marín, Héctor; Kneib, Jean-Paul; Nichol, Robert C; Olmstead, Matthew D; Prada, Francisco; Rossi, Graziano; Salazar-Albornoz, Salvador; Samushia, Lado; Sánchez, Ariel G; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Weinberg, David H; Zhu, Fangzhou
2016-01-01
We perform a tomographic baryon acoustic oscillations (BAO) analysis using the monopole, quadrupole and hexadecapole of the redshift-space galaxy power spectrum measured from the pre-reconstructed combined galaxy sample of the completed Sloan Digital Sky Survey (SDSS-III) Baryon Oscillation Spectroscopic Survey (BOSS) Data Release (DR)12 covering the redshift range of $0.20
Alam, Shadab; Bailey, Stephen; Beutler, Florian; Bizyaev, Dmitry; Blazek, Jonathan A; Bolton, Adam S; Brownstein, Joel R; Burden, Angela; Chuang, Chia-Hsun; Comparat, Johan; Cuesta, Antonio J; Dawson, Kyle S; Eisenstein, Daniel J; Escoffier, Stephanie; Gil-Marín, Héctor; Grieb, Jan Niklas; Hand, Nick; Ho, Shirley; Kinemuchi, Karen; Kirkby, David; Kitaura, Francisco; Malanushenko, Elena; Malanushenko, Viktor; Maraston, Claudia; McBride, Cameron K; Nichol, Robert C; Olmstead, Matthew D; Oravetz, Daniel; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Pellejero-Ibanez, Marcos; Percival, Will J; Petitjean, Patrick; Prada, Francisco; Price-Whelan, Adrian M; Reid, Beth A; Rodríguez-Torres, Sergio A; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Rossi, Graziano; Rubiño-Martín, Jose Alberto; Sánchez, Ariel G; Saito, Shun; Salazar-Albornoz, Salvador; Samushia, Lado; Satpathy, Siddharth; Scóccola, Claudia G; Schlegel, David J; Schneider, Donald P; Seo, Hee-Jong; Simmons, Audrey; Slosar, Anže; Strauss, Michael A; Swanson, Molly E C; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Magaña, Mariana Vargas; Vazquez, Jose Alberto; Verde, Licia; Wake, David A; Wang, Yuting; Weinberg, David H; White, Martin; Wood-Vasey, W Michael; Yèche, Christophe; Zehavi, Idit; Zhai, Zhongxu; Zhao, Gong-Bo
2016-01-01
We present cosmological results from the final galaxy clustering data set of the Baryon Oscillation Spectroscopic Survey, part of the Sloan Digital Sky Survey III. Our combined galaxy sample comprises 1.2 million massive galaxies over an effective area of 9329 deg^2 and volume of 18.7 Gpc^3, divided into three partially overlapping redshift slices centred at effective redshifts 0.38, 0.51, and 0.61. We measure the angular diameter distance DM and Hubble parameter H from the baryon acoustic oscillation (BAO) method after applying reconstruction to reduce non-linear effects on the BAO feature. Using the anisotropic clustering of the pre-reconstruction density field, we measure the product DM*H from the Alcock-Paczynski (AP) effect and the growth of structure, quantified by f{\\sigma}8(z), from redshift-space distortions (RSD). We combine measurements presented in seven companion papers into a set of consensus values and likelihoods, obtaining constraints that are tighter and more robust than those from any one m...
Gil-Marín, Héctor; Cuesta, Antonio J; Brownstein, Joel R; Chuang, Chia-Hsun; Ho, Shirley; Kitaura, Francisco-Shu; Maraston, Claudia; Prada, Francisco; Rodríguez-Torres, Sergio; Ross, Ashely J; Schlegel, David J; Schneider, Donald P; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Magaña, Mariana Vargas; Zhao, Gong-Bo
2015-01-01
[abridged] We present an anisotropic analysis of the baryonic acoustic oscillation (BAO) scale in the twelfth and final data release of the Baryonic Oscillation Spectroscopic Survey (BOSS). We independently analyse the LOWZ and CMASS galaxy samples: the LOWZ sample contains contains 361\\,762 galaxies with an effective redshift of $z_{\\rm LOWZ}=0.32$, and the CMASS sample consists of 777\\,202 galaxies with an effective redshift of $z_{\\rm CMASS}=0.57$. We extract the BAO peak position from the monopole power spectrum moment, $\\alpha_0$, and from the $\\mu^2$ moment, $\\alpha_2$. We report $H(z_{\\rm LOWZ})r_s(z_d)=(11.64\\pm0.62)\\cdot10^3\\,{\\rm km}s^{-1}$ and $D_A(z_{\\rm LOWZ})/r_s(z_d)=6.85\\pm0.17$ with a cross-correlation coefficient of $r_{HD_A}=0.42$, for the LOWZ sample; and $H(z_{\\rm CMASS})r_s(z_d)=(14.56\\pm0.38)\\cdot10^3\\,{\\rm km}s^{-1}$ and $D_A(z_{\\rm CMASS})/r_s(z_d)=9.42\\pm0.13$ with a cross-correlation coefficient of $r_{HD_A}=0.51$, for the CMASS sample. We combine these results with the measurements...
Beutler, Florian; Saito, Shun; Chuang, Chia-Hsun; Cuesta, Antonio J; Eisenstein, Daniel J; Gil-Marín, Héctor; Grieb, Jan Niklas; Hand, Nick; Kitaura, Francisco-Shu; Modi, Chirag; Nichol, Robert C; Olmstead, Matthew D; Percival, Will J; Prada, Francisco; Sánchez, Ariel G; Rodriguez-Torres, Sergio; Ross, Ashley J; Ross, Nicholas P; Schneider, Donald P; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magaña, Mariana
2016-01-01
We investigate the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12) sample, which consists of $1\\,198\\,006$ galaxies in the redshift range $0.2 < z < 0.75$ and a sky coverage of $10\\,252\\,$deg$^2$. We analyse this dataset in Fourier space, using the power spectrum multipoles to measure Redshift-Space Distortions (RSD) simultaneously with the Alcock-Paczynski (AP) effect and the Baryon Acoustic Oscillation (BAO) scale. We include the power spectrum monopole, quadrupole and hexadecapole in our analysis and compare our measurements with a perturbation theory based model, while properly accounting for the survey window function. To evaluate the reliability of our analysis pipeline we participate in a mock challenge, which resulted in systematic uncertainties significantly smaller than the statistical uncertainties. While the high-redshift constraint on $f\\sigma_8$ at $z_{\\rm eff}=0.61$ indicates a small ($\\sim 1.4\\sigma$) deviation from the prediction of th...
Kitaura, Francisco-Shu; Chuang, Chia-Hsun; Zhao, Cheng; Prada, Francisco; Gil-Marin, Hector; Guo, Hong; Yepes, Gustavo; Klypin, Anatoly; Scoccola, Claudia G; Tinker, Jeremy; McBride, Cameron; Reid, Beth; Sanchez, Ariel G; Salazar-Albornoz, Salvador; Grieb, Jan Niklas; Vargas-Magana, Mariana; Cuesta, Antonio J; Neyrinck, Mark; Beutler, Florian; Comparat, Johan; Percival, Will; Ross, Ashley
2015-01-01
We reproduce the galaxy clustering catalogue from the SDSS-III Baryon Oscillations Spectroscopic Survey Data Release 12 (BOSS DR12) with high fidelity on all relevant scales in order to allow a robust analysis of baryon acoustic oscillations and redshift space distortions. We have generated 12,288 MultiDark patchy light-cones corresponding to an effective volume of ~192,000 [Gpc/h]^3 (the largest ever simulated volume), including cosmic evolution in the range from 0.15 to 0.75. The mocks have been calibrated using a reference galaxy catalogue based on the Halo Abundance Matching modelling of the BOSS DR12 galaxy clustering data and on the data themselves. The production of the MultiDark PATCHY BOSS DR12 mocks follows three steps. First, we apply the PATCHY-code to generate a dark matter field and an object distribution including nonlinear stochastic galaxy bias. Second, we run the halo/stellar distribution reconstruction HADRON-code to assign masses to the various objects. This step uses the mass distribution...
Zhao, Gong-Bo; Wang, Yuting; Saito, Shun; Wang, Dandan; Ross, Ashley J.; Beutler, Florian; Grieb, Jan Niklas; Chuang, Chia-Hsun; Kitaura, Francisco-Shu; Rodriguez-Torres, Sergio; Percival, Will J.; Brownstein, Joel R.; Cuesta, Antonio J.; Eisenstein, Daniel J.; Gil-Marín, Héctor; Kneib, Jean-Paul; Nichol, Robert C.; Olmstead, Matthew D.; Prada, Francisco; Rossi, Graziano; Salazar-Albornoz, Salvador; Samushia, Lado; Sánchez, Ariel G.; Thomas, Daniel; Tinker, Jeremy L.; Tojeiro, Rita; Weinberg, David H.; Zhu, Fangzhou
2017-04-01
We perform a tomographic baryon acoustic oscillations (BAO) analysis using the monopole, quadrupole and hexadecapole of the redshift-space galaxy power spectrum measured from the pre-reconstructed combined galaxy sample of the completed Sloan Digital Sky Survey Baryon Oscillation Spectroscopic Survey (BOSS) Data Release12 covering the redshift range of 0.20 < z < 0.75. By allowing for overlap between neighbouring redshift slices, we successfully obtained the isotropic and anisotropic BAO distance measurements within nine redshift slices to a precision of 1.5-3.4 per cent for DV/rd, 1.8-4.2 per cent for DA/rd and 3.7-7.5 per cent for H rd, depending on effective redshifts. We provide our BAO measurement of DA/rd and H rd with the full covariance matrix, which can be used for cosmological implications. Our measurements are consistent with those presented in Alam et al., in which the BAO distances are measured at three effective redshifts. We constrain dark energy parameters using our measurements and find an improvement of the Figure-of-Merit of dark energy in general due to the temporal BAO information resolved. This paper is a part of a set that analyses the final galaxy clustering data set from BOSS.
Grieb, Jan Niklas; Salazar-Albornoz, Salvador; Scoccimarro, Román; Crocce, Martín; Vecchia, Claudio Dalla; Montesano, Francesco; Gil-Marín, Héctor; Ross, Ashley J; Beutler, Florian; Rodríguez-Torres, Sergio; Chuang, Chia-Hsun; Prada, Francisco; Kitaura, Francisco-Shu; Cuesta, Antonio J; Eisenstein, Daniel J; Percival, Will J; Vargas-Magana, Mariana; Tinker, Jeremy L; Tojeiro, Rita; Brownstein, Joel R; Maraston, Claudia; Nichol, Robert C; Olmstead, Matthew D; Samushia, Lado; Seo, Hee-Jong; Streblyanska, Alina; Zhao, Gong-bo
2016-01-01
We extract cosmological information from the anisotropic power spectrum measurements from the recently completed Baryon Oscillation Spectroscopic Survey (BOSS), extending the concept of clustering wedges to Fourier space. Making use of new FFT-based estimators, we measure the power spectrum clustering wedges of the BOSS sample by filtering out the information of Legendre multipoles l > 4. Our modelling of these measurements is based on novel approaches to describe non-linear evolution, bias, and redshift-space distortions, which we test using synthetic catalogues based on large-volume N-body simulations. We are able to include smaller scales than in previous analyses, resulting in tighter cosmological constraints. Using three overlapping redshift bins, we measure the angular diameter distance, the Hubble parameter, and the cosmic growth rate, and explore the cosmological implications of our full shape clustering measurements in combination with CMB and SN Ia data. Assuming a {\\Lambda}CDM cosmology, we constra...
Gil-Marín, Héctor; Brownstein, Joel R; Chuang, Chia-Hsun; Grieb, Jan Niklas; Ho, Shirley; Kitaura, Francisco-Shu; Maraston, Claudia; Prada, Francisco; Rodríguez-Torres, Sergio; Ross, Ashley J; Samushia, Lado; Schlegel, David J; Thomas, Daniel; Tinker, Jeremy L; Zhao, Gong-Bo
2015-01-01
We measure and analyse the clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) relative to the line-of-sight (LOS), for LOWZ and CMASS galaxy samples drawn from the final Data Release 12 (DR12). The LOWZ sample contains 361\\,762 galaxies with an effective redshift of $z_{\\rm lowz}=0.32$, and the CMASS sample 777\\,202 galaxies with an effective redshift of $z_{\\rm cmass}=0.57$. From the power spectrum monopole and quadrupole moments around the LOS, we measure the growth of structure parameter $f$ times the amplitude of dark matter density fluctuations $\\sigma_8$ by modeling the Redshift-Space Distortion signal. When the geometrical Alcock-Paczynski effect is also constrained from the same data, we find joint constraints on $f\\sigma_8$, the product of the Hubble constant and the comoving sound horizon at the baryon drag epoch $H(z)r_s(z_d)$, and the angular distance parameter divided by the sound horizon $D_A(z)/r_s(z_d)$. We find $f(z_{\\rm lowz})\\sigma_8(z_{\\rm lowz})=0.394\\pm0.062$, $D_A(z_{\\rm l...
Gil-Marín, Héctor; Verde, Licia; Brownstein, Joel R; Chuang, Chia-Hsun; Kitaura, Francisco-Shu; Rodríguez-Torres, Sergio A; Olmstead, Matthew D
2016-01-01
We measure and analyse the bispectrum of the final, Data Release 12, galaxy sample provided by the Baryon Oscillation Spectroscopic Survey, splitting by selection algorithm into LOWZ and CMASS galaxies. The LOWZ sample contains 361762 galaxies with an effective redshift of $z_{\\rm LOWZ}=0.32$, and the CMASS sample 777202 galaxies with an effective redshift of $z_{\\rm CMASS}=0.57$. Combining the power spectrum, measured relative to the line-of-sight, with the spherically averaged bispectrum, we are able to constrain the product of the growth of structure parameter, $f$, and the amplitude of dark matter density fluctuations, $\\sigma_8$, along with the geometric Alcock-Paczynski parameters, the product of the Hubble constant and the comoving sound horizon at the baryon drag epoch, $H(z)r_s(z_d)$, and the angular distance parameter divided by the sound horizon, $D_A(z)/r_s(z_d)$. We find $f(z_{\\rm LOWZ})\\sigma_8(z_{\\rm LOWZ})=0.460\\pm 0.066$, $D_A(z_{\\rm LOWZ})/r_s(z_d)=6.74 \\pm 0.22$, $H(z_{\\rm LOWZ})r_s(z_d)=(1...
Gil-Marín, Héctor; Percival, Will J.; Verde, Licia; Brownstein, Joel R.; Chuang, Chia-Hsun; Kitaura, Francisco-Shu; Rodríguez-Torres, Sergio A.; Olmstead, Matthew D.
2017-02-01
We measure and analyse the bispectrum of the final data release 12 (DR12), galaxy sample provided by the Baryon Oscillation Spectroscopic Survey, splitting by selection algorithm into LOWZ and CMASS galaxies. The LOWZ sample contains 361 762 galaxies with an effective redshift of zLOWZ = 0.32, and the CMASS sample contains 777 202 galaxies with an effective redshift of zCMASS = 0.57. Combining the power spectrum, measured relative to the line of sight, with the spherically averaged bispectrum, we are able to constrain the product of the growth of structure parameter, f, and the amplitude of dark matter density fluctuations, σ8, along with the geometric Alcock-Paczynski parameters, the product of the Hubble constant and the comoving sound horizon at the baryon drag epoch, H(z)rs(zd), and the angular distance parameter divided by the sound horizon, DA(z)/rs(zd). After combining pre-reconstruction RSD analyses of the power spectrum monopole, quadrupole and bispectrum monopole with post-reconstruction analysis of the BAO power spectrum monopole and quadrupole, we find f(zLOWZ)σ8(zLOWZ) = 0.427 ± 0.056, DA(zLOWZ)/rs(zd) = 6.60 ± 0.13, H(zLOWZ)rs(zd) = (11.55 ± 0.38)103 km s-1 for the LOWZ sample, and f(zCMASS)σ8(zCMASS) = 0.426 ± 0.029, DA(zCMASS)/rs(zd) = 9.39 ± 0.10, H(zCMASS)rs(zd) = (14.02 ± 0.22)103 km s-1 for the CMASS sample. We find general agreement with previous Baryon Oscillation Spectroscopic Survey DR11 and DR12 measurements. Combining our data set with Planck15 we perform a null test of General Relativity through the γ-parametrization finding γ =0.733^{+0.068}_{-0.069}, which is ∼2.7σ away from the General Relativity predictions.
Schaan, Emmanuel; Ferraro, Simone; Vargas-Magaña, Mariana; Smith, Kendrick M.; Ho, Shirley; Aiola, Simone; Battaglia, Nicholas; Bond, J. Richard; De Bernardis, Francesco; Calabrese, Erminia; Cho, Hsiao-Mei; Devlin, Mark J.; Dunkley, Joanna; Gallardo, Patricio A.; Hasselfield, Matthew; Henderson, Shawn; Hill, J. Colin; Hincks, Adam D.; Hlozek, Renée; Hubmayr, Johannes; Hughes, John P.; Irwin, Kent D.; Koopman, Brian; Kosowsky, Arthur; Li, Dale; Louis, Thibaut; Lungu, Marius; Madhavacheril, Mathew; Maurin, Loïc; McMahon, Jeffrey John; Moodley, Kavilan; Naess, Sigurd; Nati, Federico; Newburgh, Laura; Niemack, Michael D.; Page, Lyman A.; Pappas, Christine G.; Partridge, Bruce; Schmitt, Benjamin L.; Sehgal, Neelima; Sherwin, Blake D.; Sievers, Jonathan L.; Spergel, David N.; Staggs, Suzanne T.; van Engelen, Alexander; Wollack, Edward J.; ACTPol Collaboration
2016-04-01
We use microwave temperature maps from two seasons of data from the Atacama Cosmology Telescope at 146 GHz, together with the "Constant Mass" CMASS galaxy sample from the Baryon Oscillation Spectroscopic Survey to measure the kinematic Sunyaev-Zel'dovich (kSZ) effect over the redshift range z =0.4 - 0.7 . We use galaxy positions and the continuity equation to obtain a reconstruction of the line-of-sight velocity field. We stack the microwave temperature at the location of each halo, weighted by the corresponding reconstructed velocity. We vary the size of the aperture photometry filter used, thus probing the free electron profile of these halos from within the virial radius out to three virial radii, on the scales relevant for investigating the missing baryons problem. The resulting best fit kSZ model is preferred over the no-kSZ hypothesis at 3.3 and 2.9 σ for two independent velocity reconstruction methods, using 25,537 galaxies over 660 square degrees. The data suggest that the baryon profile is shallower than the dark matter in the inner regions of the halos probed here, potentially due to energy injection from active galactic nucleus or supernovae. Thus, by constraining the gas profile on a wide range of scales, this technique will be useful for understanding the role of feedback in galaxy groups and clusters. The effect of foregrounds that are uncorrelated with the galaxy velocities is expected to be well below our signal, and residual thermal Sunyaev-Zel'dovich contamination is controlled by masking the most massive clusters. Finally, we discuss the systematics involved in converting our measurement of the kSZ amplitude into the mean free electron fraction of the halos in our sample.
Chuang, Chia-Hsun; Beutler, Florian; Eisenstein, Daniel J; Escoffier, Stephanie; Ho, Shirley; Kneib, Jean-Paul; Manera, Marc; Nuza, Sebastian E; Schlegel, David J; Schneider, Donald P; Weaver, Benjamin A; Brownstein, Joel R; Dawson, Kyle S; Maraston, Claudia; Thomas, Daniel
2013-01-01
With the largest spectroscopic galaxy survey volume drawn from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), we can extract cosmological constraints from the measurements of redshift and geometric distortions at quasi-linear scales (e.g. above 50 Mpc/h), which can be modeled by perturbation theory. We analyze the broad-range shape of the monopole and quadrupole correlation functions of the BOSS Data Release 11 (DR11) CMASS galaxy sample, at the effective redshift z=0.57, to obtain constraints on the Hubble expansion rate H(z), the angular-diameter distance D_A(z), the normalized growth rate f(z)\\sigma_8(z), and the physical matter density \\Omega_mh^2. We provide accurate measurements on {H^{-1}R_{fid}^{-1.0}, D_A R_{fid}^{-0.96}, f\\sigma_8(\\Omega_m h^2)^{0.45}}, where R_{fid}\\equiv r_s/r_{s,fid}, r_s is the comoving sound horizon at the drag epoch, and r_{s,fid} is the sound scale of the fiducial cosmology used in this study. We also extract cosmological constraints from BOSS DR11 LOWZ sample, ...
Sánchez, Ariel G.; Scoccimarro, Román; Crocce, Martín; Grieb, Jan Niklas; Salazar-Albornoz, Salvador; Dalla Vecchia, Claudio; Lippich, Martha; Beutler, Florian; Brownstein, Joel R.; Chuang, Chia-Hsun; Eisenstein, Daniel J.; Kitaura, Francisco-Shu; Olmstead, Matthew D.; Percival, Will J.; Prada, Francisco; Rodríguez-Torres, Sergio; Ross, Ashley J.; Samushia, Lado; Seo, Hee-Jong; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magaña, Mariana; Wang, Yuting; Zhao, Gong-Bo
2017-01-01
We explore the cosmological implications of anisotropic clustering measurements in configuration space of the final galaxy samples from Data Release 12 of the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey. We implement a new detailed modelling of the effects of non-linearities, bias and redshift-space distortions that can be used to extract unbiased cosmological information from our measurements for scales s ≳ 20 h-1 Mpc. We combined the information from Baryon Oscillation Spectroscopic Survey (BOSS) with the latest cosmic microwave background (CMB) observations and Type Ia supernovae samples and found no significant evidence for a deviation from the Λ cold dark matter (ΛCDM) cosmological model. In particular, these data sets can constrain the dark energy equation-of-state parameter to wDE = -0.996 ± 0.042 when to be assumed time independent, the curvature of the Universe to Ωk = -0.0007 ± 0.0030 and the sum of the neutrino masses to ∑mν < 0.25 eV at 95 per cent confidence levels. We explore the constraints on the growth rate of cosmic structures assuming f(z) = Ωm(z)γ and obtain γ = 0.609 ± 0.079, in good agreement with the predictions of general relativity of γ = 0.55. We compress the information of our clustering measurements into constraints on the parameter combinations DV(z)/rd, FAP(z) and fσ8(z) at zeff = 0.38, 0.51 and 0.61 with their respective covariance matrices and find good agreement with the predictions for these parameters obtained from the best-fitting ΛCDM model to the CMB data from the Planck satellite. This paper is part of a set that analyses the final galaxy clustering data set from BOSS. The measurements and likelihoods presented here are combined with others by Alam et al. to produce the final cosmological constraints from BOSS.
Reid, Beth A; White, Martin; Percival, Will J; Manera, Marc; Padmanabhan, Nikhil; Ross, Ashley J; Sánchez, Ariel G; Bailey, Stephen; Bizyaev, Dmitry; Bolton, Adam S; Brewington, Howard; Brinkmann, J; Brownstein, Joel R; Cuesta, Antonio J; Eisenstein, Daniel J; Gunn, James E; Honscheid, Klaus; Malanushenko, Elena; Malanushenko, Viktor; Maraston, Claudia; McBride, Cameron K; Muna, Demitri; Nichol, Robert C; Oravetz, Daniel; Pan, Kaike; de Putter, Roland; Roe, N A; Ross, Nicholas P; Schlegel, David J; Schneider, Donald P; Seo, Hee-Jong; Shelden, Alaina; Sheldon, Erin S; Simmons, Audrey; Skibba, Ramin A; Snedden, Stephanie; Swanson, Molly E C; Thomas, Daniel; Tinker, Jeremy; Tojeiro, Rita; Verde, Licia; Wake, David A; Weaver, Benjamin A; Weinberg, David H; Zehavi, Idit; Zhao, Gong-Bo
2012-01-01
We analyze the anisotropic clustering of massive galaxies from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) sample, which consists of 264,283 galaxies in the redshift range 0.43 0.57, and when combined imply \\Omega_{\\Lambda} = 0.74 +/- 0.016, independent of the Universe's evolution at z<0.57. In our companion paper (Samushia et al. prep), we explore further cosmological implications of these observations.
Guo, Hong; Zehavi, Idit; Xu, Haojie; Eisenstein, Daniel J; Weinberg, David H; Bahcall, Neta A; Berlind, Andreas A; Comparat, Johan; McBride, Cameron K; Ross, Ashley J; Schneider, Donald P; Skibba, Ramin A; Swanson, Molly E C; Tinker, Jeremy L; Tojeiro, Rita; Wake, David A
2014-01-01
We investigate the luminosity and colour dependence of clustering of CMASS galaxies in the Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey Tenth Data Release. The halo occupation distribution framework is adopted to model the projected two-point correlation function measurements on small and intermediate scales (from $0.02$ to $60\\,h^{-1}{\\rm {Mpc}}$) and to interpret the observed trends and infer the connection of galaxies to dark matter halos. We find that luminous red galaxies reside in massive halos of mass $M{\\sim}10^{13}$--$10^{14}\\,h^{-1}{\\rm M_\\odot}$ and more luminous galaxies are more clustered and hosted by more massive halos. The strong small-scale clustering requires a fraction of these galaxies to be satellites in massive halos, with the fraction at the level of 5--8 per cent and decreasing with luminosity. The characteristic mass of a halo hosting on average one satellite galaxy above a luminosity threshold is about a factor $8.7$ larger than that of a halo hosting a centra...
Wiegand, Alexander
2016-01-01
We probe the higher-order clustering of the galaxies in the final data release (DR12) of the Sloan Digital Sky Survey Baryon Oscillation Spectroscopic Survey (BOSS) using the method of germ-grain Minkowski Functionals (MFs). Our sample consists of 410,615 BOSS galaxies from the northern Galactic cap in the redshift range 0.450--0.595. We show the MFs to be sensitive to contributions up to the six-point correlation function for this data set. We ensure with a custom angular mask that the results are more independent of boundary effects than in previous analyses of this type. We extract the higher-order part of the MFs and quantify the difference to the case without higher-order correlations. The resulting $\\chi^{2}$ value of over 10,000 for a modest number of degrees of freedom, O(200), indicates a 100-sigma deviation and demonstrates that we have a highly significant signal of the non-Gaussian contributions to the galaxy distribution. This statistical power can be useful in testing models with differing highe...
Sanchez, Ariel G; Crocce, Martin; Grieb, Jan Niklas; Salazar-Albornoz, Salvador; DallaVecchia, Claudio; Lippich, Martha; Beutler, Florian; Brownstein, Joel R; Chuang, Chia-Hsun; Eisenstein, Daniel J; Kitaura, Francisco-Shu; Olmstead, Matthew D; Percival, Will J; Prada, Francisco; Rodriguez-Torres, Sergio; Ross, Ashley J; Samushia, Lado; Seo, Hee-Jong; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magana, Mariana; Wang, Yuting; Zhao, Gong-Bo
2016-01-01
We explore the cosmological implications of anisotropic clustering measurements in configuration space of the final galaxy samples from Data Release 12 of the SDSS-III Baryon Oscillation Spectroscopic Survey. We implement a new detailed modelling of the effects of non-linearities, galaxy bias and redshift-space distortions that can be used to extract unbiased cosmological information from our measurements for scales $s \\gtrsim 20\\,h^{-1}{\\rm Mpc}$. We combined the galaxy clustering information from BOSS with the latest cosmic microwave background (CMB) observations and Type Ia supernovae samples and found no significant evidence for a deviation from the $\\Lambda$CDM cosmological model. In particular, these data sets can constrain the dark energy equation of state parameter to $w_{\\rm DE}=-0.996\\pm0.042$ when assumed time-independent, the curvature of the Universe to $\\Omega_{k}=-0.0007\\pm 0.0030$ and the sum of the neutrino masses to $\\sum m_{\
Ata, Metin; Chuang, Chia-Hsun; Rodríguez-Torres, Sergio; Angulo, Raul E; Ferraro, Simone; McDonald, Patrick; Monteagudo, Carlos Hernández; Müller, Volker; Yepes, Gustavo; Baumgarten, Falk; Beutler, Florian; Brownstein, Joel R; Burden, Angela; Eisenstein, Daniel J; Guo, Hong; Ho, Shirley; McBride, Cameron; Neyrinck, Mark; Olmstead, Matthew D; Padmanabhan, Nikhil; Perciva, Will J; Prada, Francisco; Rossi, Graziano; Sánchez, Ariel G; Schlege, David; Schneider, Donald P; Seo, Hee-Jong; Streblyanska, Alina; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magana, Mariana
2016-01-01
We present a Bayesian phase space reconstruction of the cosmic large-scale matter density and velocity fields from the SDSS-III Baryon Oscillations Spectroscopic Survey Data Release 12 (BOSS DR12) CMASS galaxy clustering catalogue. We rely on a given $\\Lambda$CDM cosmology, a mesh resolution in the range of 6-10 $h^{-1}$ Mpc, and a lognormal-Poisson model with a redshift dependent nonlinear bias. The bias parameters are derived from the data and a general renormalised perturbation theory approach. We use combined Gibbs and Hamiltonian sampling, implemented in the \\textsc{argo} code, to iteratively reconstruct the dark matter density field and the coherent peculiar velocities of individual galaxies, correcting hereby for coherent redshift space distortions (RSD). Our tests relying on accurate $N$-body based mock galaxy catalogues, show unbiased real space power spectra of the nonlinear density field up to $k\\sim0.2\\, h$ Mpc$^{-1}$, and vanishing quadrupoles down to $\\sim20\\,h^{-1}$ Mpc. We also demonstrate tha...
Grieb, Jan Niklas; Sánchez, Ariel G.; Salazar-Albornoz, Salvador; Scoccimarro, Román; Crocce, Martín; Dalla Vecchia, Claudio; Montesano, Francesco; Gil-Marín, Héctor; Ross, Ashley J.; Beutler, Florian; Rodríguez-Torres, Sergio; Chuang, Chia-Hsun; Prada, Francisco; Kitaura, Francisco-Shu; Cuesta, Antonio J.; Eisenstein, Daniel J.; Percival, Will J.; Vargas-Magaña, Mariana; Tinker, Jeremy L.; Tojeiro, Rita; Brownstein, Joel R.; Maraston, Claudia; Nichol, Robert C.; Olmstead, Matthew D.; Samushia, Lado; Seo, Hee-Jong; Streblyanska, Alina; Zhao, Gong-bo
2017-01-01
We extract cosmological information from the anisotropic power spectrum measurements from the recently completed Baryon Oscillation Spectroscopic Survey (BOSS), extending the concept of clustering wedges to Fourier space. Making use of new FFT-based estimators, we measure the power spectrum clustering wedges of the BOSS sample by filtering out the information of Legendre multipoles ℓ > 4. Our modelling of these measurements is based on novel approaches to describe non-linear evolution, bias, and redshift-space distortions, which we test using synthetic catalogues based on large-volume N-body simulations. We are able to include smaller scales than in previous analyses, resulting in tighter cosmological constraints. Using three overlapping redshift bins, we measure the angular diameter distance, the Hubble parameter, and the cosmic growth rate, and explore the cosmological implications of our full shape clustering measurements in combination with CMB and SN Ia data. Assuming a ΛCDM cosmology, we constrain the matter density to Ω M= 0.311_{-0.010}^{+0.009} and the Hubble parameter to H_0 = 67.6_{-0.6}^{+0.7} km s^{-1} Mpc^{-1}, at a confidence level (CL) of 68 per cent. We also allow for non-standard dark energy models and modifications of the growth rate, finding good agreement with the ΛCDM paradigm. For example, we constrain the equation-of-state parameter to w = -1.019_{-0.039}^{+0.048}. This paper is part of a set that analyses the final galaxy clustering dataset from BOSS. The measurements and likelihoods presented here are combined with others in Alam et al. (2016) to produce the final cosmological constraints from BOSS.
Ata, Metin; Kitaura, Francisco-Shu; Chuang, Chia-Hsun; Rodríguez-Torres, Sergio; Angulo, Raul E.; Ferraro, Simone; Gil-Marín, Hector; McDonald, Patrick; Monteagudo, Carlos Hernández; Müller, Volker; Yepes, Gustavo; Autefage, Mathieu; Baumgarten, Falk; Beutler, Florian; Brownstein, Joel R.; Burden, Angela; Eisenstein, Daniel J.; Guo, Hong; Ho, Shirley; McBride, Cameron; Neyrinck, Mark; Olmstead, Matthew D.; Padmanabhan, Nikhil; Percival, Will J.; Prada, Francisco; Rossi, Graziano; Sánchez, Ariel G.; Schlegel, David; Schneider, Donald P.; Seo, Hee-Jong; Streblyanska, Alina; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magana, Mariana
2017-01-01
We present a Bayesian phase-space reconstruction of the cosmic large-scale matter density and velocity fields from the SDSS-III Baryon Oscillations Spectroscopic Survey Data Release 12 (BOSS DR12) CMASS galaxy clustering catalogue. We rely on a given ΛCDM cosmology, a mesh resolution in the range of 6-10 h-1 Mpc, and a lognormal-Poisson model with a redshift dependent nonlinear bias. The bias parameters are derived from the data and a general renormalised perturbation theory approach. We use combined Gibbs and Hamiltonian sampling, implemented in the ARGO code, to iteratively reconstruct the dark matter density field and the coherent peculiar velocities of individual galaxies, correcting hereby for coherent redshift space distortions (RSD). Our tests relying on accurate N-body based mock galaxy catalogues, show unbiased real space power spectra of the nonlinear density field up to k ˜ 0.2 h Mpc-1, and vanishing quadrupoles down to r ˜ 20 h-1 Mpc. We also demonstrate that the nonlinear cosmic web can be obtained from the tidal field tensor based on the Gaussian component of the reconstructed density field. We find that the reconstructed velocities have a statistical correlation coefficient compared to the true velocities of each individual lightcone mock galaxy of r ˜ 0.68 including about 10% of satellite galaxies with virial motions (about r = 0.75 without satellites). The power spectra of the velocity divergence agree well with theoretical predictions up to k ˜ 0.2 h Mpc-1. This work will be especially useful to improve, e.g. BAO reconstructions, kinematic Sunyaev-Zeldovich (kSZ), integrated Sachs-Wolfe (ISW) measurements, or environmental studies.
Chuang, Chia-Hsun; Prada, Francisco; Pellejero-Ibanez, Marcos; Beutler, Florian; Cuesta, Antonio J.; Eisenstein, Daniel J.; Escoffier, Stephanie; Ho, Shirley; Kitaura, Francisco-Shu; Kneib, Jean-Paul; Manera, Marc; Nuza, Sebastián E.; Rodríguez-Torres, Sergio; Ross, Ashley; Rubiño-Martín, J. A.; Samushia, Lado; Schlegel, David J.; Schneider, Donald P.; Wang, Yuting; Weaver, Benjamin A.; Zhao, Gongbo; Brownstein, Joel R.; Dawson, Kyle S.; Maraston, Claudia; Olmstead, Matthew D.; Thomas, Daniel
2016-10-01
With the largest spectroscopic galaxy survey volume drawn from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), we can extract cosmological constraints from the measurements of redshift and geometric distortions at quasi-linear scales (e.g. above 50 h-1 Mpc). We analyse the broad-range shape of the monopole and quadrupole correlation functions of the BOSS Data Release 12 (DR12) CMASS galaxy sample, at the effective redshift z = 0.59, to obtain constraints on the Hubble expansion rate H(z), the angular- diameter distance DA(z), the normalized growth rate f(z)σ8(z), and the physical matter density Ωm h2. We obtain robust measurements by including a polynomial as the model for the systematic errors, and find it works very well against the systematic effects, e.g. ones induced by stars and seeing. We provide accurate measurements {DA(0.59)rs,fid/rs, H(0.59)rs/rs,fid, f(0.59)σ8(0.59), Ωm h2} = {1427 ± 26 Mpc, 97.3 ± 3.3 km s-1 Mpc-1, 0.488 ± 0.060, 0.135 ± 0.016}, where rs is the comoving sound horizon at the drag epoch and rs,fid = 147.66 Mpc is the sound scale of the fiducial cosmology used in this study. The parameters which are not well constrained by our galaxy clustering analysis are marginalized over with wide flat priors. Since no priors from other data sets, e.g. cosmic microwave background (CMB), are adopted and no dark energy models are assumed, our results from BOSS CMASS galaxy clustering alone may be combined with other data sets, i.e. CMB, SNe, lensing or other galaxy clustering data to constrain the parameters of a given cosmological model. The uncertainty on the dark energy equation of state parameter, w, from CMB+CMASS is about 8 per cent. The uncertainty on the curvature fraction, Ωk, is 0.3 per cent. We do not find deviation from flat ΛCDM.
Kazin, Eyal A; Cuesta, Antonio J; Beutler, Florian; Chuang, Chia-Hsun; Eisenstein, Daniel J; Manera, Marc; Padmanabhan, Nikhil; Percival, Will J; Prada, Francisco; Ross, Ashley J; Seo, Hee-Jong; Tinker, Jeremy; Tojeiro, Rita; Xu, Xiaoying; Brinkmann, J; Joel, Brownstein; Nichol, Robert C; Schlegel, David J; Schneider, Donald P; Thomas, Daniel
2013-01-01
We analyze the 2D correlation function of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) CMASS sample of massive galaxies of the ninth data release to measure cosmic expansion H and the angular diameter distance D_A at a mean redshift of = 0.57. We apply, for the first time, a new correlation function technique called clustering wedges. Using a physically motivated model, the anisotropic baryonic acoustic feature in the galaxy sample is detected at a significance level of 4.7 sigma compared to a featureless model. The baryonic acoustic feature is used to obtain model independent constraints cz/H/r_s = 12.28 +- 0.82 (6.7 per-cent accuracy) and D_A/r_s = 9.05 +- 0.27 (3.0 per-cent) with a correlation coefficient of -0.5, where r_s is the sound horizon scale at the end of the baryonic drag era. We conduct thorough tests on the data and 600 simulated realizations, finding robustness of the results regardless of the details of the analysis method. Combining with r_s constraints from the Cosmic Microw...
Tojeiro, Rita; Burden, Angela; Samushia, Lado; Manera, Marc; Percival, Will J; Beutler, Florian; Cuesta, Antonio J; Dawson, Kyle; Eisenstein, Daniel J; Ho, Shirley; Howett, Cullan; McBride, Cameron K; Montesano, Francisco; Parejko, John K; Reid, Beth; Sánchez, Ariel G; Schlegel, David J; Schneider, Donald P; Tinker, Jeremy L; Magaña, Mariana Vargas; White, Martin
2014-01-01
We present the distance measurement to z = 0.32 using the 11th data release of the Sloan Digital Sky Survey-III Baryon Acoustic Oscillation Survey (BOSS). We use 313,780 galaxies of the low-redshift (LOWZ) sample over 7,341 square-degrees to compute $D_V = (1264 \\pm 25)(r_d/r_{d,fid})$ - a sub 2% measurement - using the baryon acoustic feature measured in the galaxy two-point correlation function and power-spectrum. We compare our results to those obtained in DR10. We study observational systematics in the LOWZ sample and quantify potential effects due to photometric offsets between the northern and southern Galactic caps. We find the sample to be robust to all systematic effects found to impact on the targeting of higher-redshift BOSS galaxies, and that the observed north-south tensions can be explained by either limitations in photometric calibration or by sample variance, and have no impact on our final result. Our measurement, combined with the baryonic acoustic scale at z = 0.57, is used in Anderson et a...
C P -violating baryon oscillations
McKeen, David; Nelson, Ann E.
2016-10-01
We enumerate the conditions necessary for C P violation to be manifest in n -n ¯ oscillations and build a simple model that can give rise to such effects. We discuss a possible connection between neutron oscillations and dark matter, provided the mass of the latter lies between mp-me and mp+me. We apply our results to a possible baryogenesis scenario involving C P violation in the oscillations of the Ξ0.
Rodríguez-Torres, Sergio A.; Chuang, Chia-Hsun; Prada, Francisco; Guo, Hong; Klypin, Anatoly; Behroozi, Peter; Hahn, Chang Hoon; Comparat, Johan; Yepes, Gustavo; Montero-Dorta, Antonio D.; Brownstein, Joel R.; Maraston, Claudia; McBride, Cameron K.; Tinker, Jeremy; Gottlöber, Stefan; Favole, Ginevra; Shu, Yiping; Kitaura, Francisco-Shu; Bolton, Adam; Scoccimarro, Román; Samushia, Lado; Schlegel, David; Schneider, Donald P.; Thomas, Daniel
2016-08-01
We present a study of the clustering and halo occupation distribution of Baryon Oscillation Spectroscopic Survey (BOSS) CMASS galaxies in the redshift range 0.43 body simulation of a flat Λ cold dark matter Planck cosmology. We compare the observational data with the simulated ones on a light cone constructed from 20 subsequent outputs of the simulation. Observational effects such as incompleteness, geometry, veto masks and fibre collisions are included in the model, which reproduces within 1σ errors the observed monopole of the two-point correlation function at all relevant scales: from the smallest scales, 0.5 h-1 Mpc, up to scales beyond the baryon acoustic oscillation feature. This model also agrees remarkably well with the BOSS galaxy power spectrum (up to k ˜ 1 h Mpc-1), and the three-point correlation function. The quadrupole of the correlation function presents some tensions with observations. We discuss possible causes that can explain this disagreement, including target selection effects. Overall, the standard HAM model describes remarkably well the clustering statistics of the CMASS sample. We compare the stellar-to-halo mass relation for the CMASS sample measured using weak lensing in the Canada-France-Hawaii Telescope Stripe 82 Survey with the prediction of our clustering model, and find a good agreement within 1σ. The BigMD-BOSS light cone including properties of BOSS galaxies and halo properties is made publicly available.
Wang, Yuting; Chuang, Chia-Hsun; Ross, Ashley J; Percival, Will J; Gil-Marín, Héctor; Cuesta, Antonio J; Kitaura, Francisco-Shu; Rodriguez-Torres, Sergio; Brownstein, Joel R; Eisenstein, Daniel J; Ho, Shirley; Kneib, Jean-Paul; Olmstead, Matt; Prada, Francisco; Rossi, Graziano; Sánchez, Ariel G; Salazar-Albornoz, Salvador; Thomas, Daniel; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magaña, Mariana; Zhu, Fangzhou
2016-01-01
We perform a tomographic baryon acoustic oscillations analysis using the two-point galaxy correlation function measured from the combined sample of BOSS DR12, which covers the redshift range of $0.2
Flavour Oscillations in Dense Baryonic Matter
Filip, Peter
2017-01-01
We suggest that fast neutral meson oscillations may occur in a dense baryonic matter, which can influence the balance of s/¯s quarks in the nucleus-nucleus and proton-nucleus interactions, if primordial multiplicities of neutral K 0, mesons are sufficiently asymmetrical. The phenomenon can occur even if CP symmetry is fully conserved, and it may be responsible for the enhanced sub-threshold production of multi-strange hyperons observed in the low-energy A+A and p+A interactions.
Redshift uncertainties and baryonic acoustic oscillations
Chaves-Montero, Jonás; Hernández-Monteagudo, Carlos
2016-01-01
In the upcoming era of high-precision galaxy surveys, it becomes necessary to understand the impact of uncertain redshift estimators on cosmological observables. In this paper we present a detailed exploration of the galaxy clustering and baryonic acoustic oscillation (BAO) signal under the presence of redshift errors. We provide analytic expressions for how the monopole and the quadrupole of the redshift-space power spectrum (together with their covariances) are affected. Additionally, we discuss the modifications in the shape, signal to noise, and cosmological constraining power of the BAO signature. We show how and why the BAO contrast is $\\mathit{enhanced}$ with small redshift uncertainties, and explore in detail how the cosmological information is modulated by the interplay of redshift-space distortions, redshift errors, and the number density of the sample. We validate our results by comparing them with measurements from a ensemble of $N$-body simulations with $8100h^{-3}\\text{Gpc}^3$ aggregated volume....
Pellejero-Ibanez, Marcos; Rubiño-Martín, J A; Cuesta, Antonio J; Wang, Yuting; Zhao, Gong-bo; Ross, Ashley J; Rodríguez-Torres, Sergio; Prada, Francisco; Slosar, Anže; Vazquez, Jose A; Alam, Shadab; Beutler, Florian; Eisenstein, Daniel J; Gil-Marín, Héctor; Grieb, Jan Niklas; Ho, Shirley; Kitaura, Francisco-Shu; Percival, Will J; Rossi, Graziano; Salazar-Albornoz, Salvador; Samushia, Lado; Sánchez, Ariel G; Satpathy, Siddharth; Seo, Hee-Jong; Tinker, Jeremy L; Tojeiro, Rita; Vargas-Magaña, Mariana; Brownstein, Joel R; Nichol, Robert C; Olmstead, Matthew D
2016-01-01
We develop a new methodology called double-probe analysis with the aim of minimizing informative priors in the estimation of cosmological parameters. We extract the dark-energy-model-independent cosmological constraints from the joint data sets of Baryon Oscillation Spectroscopic Survey (BOSS) galaxy sample and Planck cosmic microwave background (CMB) measurement. We measure the mean values and covariance matrix of $\\{R$, $l_a$, $\\Omega_b h^2$, $n_s$, $log(A_s)$, $\\Omega_k$, $H(z)$, $D_A(z)$, $f(z)\\sigma_8(z)\\}$, which give an efficient summary of Planck data and 2-point statistics from BOSS galaxy sample, where $R=\\sqrt{\\Omega_m H_0^2}\\,r(z_*)$, and $l_a=\\pi r(z_*)/r_s(z_*)$, $z_*$ is the redshift at the last scattering surface, and $r(z_*)$ and $r_s(z_*)$ denote our comoving distance to $z_*$ and sound horizon at $z_*$ respectively. The advantage of this method is that we do not need to put informative priors on the cosmological parameters that galaxy clustering is not able to constrain well, i.e. $\\Omega_b...
Satpathy, Siddharth; Ho, Shirley; White, Martin; Bahcall, Neta A; Beutler, Florian; Brownstein, Joel R; Chuang, Chia-Hsun; Eisenstein, Daniel J; Grieb, Jan Niklas; Kitaura, Francisco; Olmstead, Matthew D; Percival, Will J; Salazar-Albornoz, Salvador; Sánchez, Ariel G; Seo, Hee-Jong; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita
2016-01-01
We present a measurement of the linear growth rate of structure, \\textit{f} from the Sloan Digital Sky Survey III (SDSS III) Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12) using Convolution Lagrangian Perturbation Theory (CLPT) with Gaussian Streaming Redshift-Space Distortions (GSRSD) to model the two point statistics of BOSS galaxies in DR12. The BOSS-DR12 dataset includes 1,198,006 massive galaxies spread over the redshift range $0.2 < z < 0.75$. These galaxy samples are categorized in three redshift bins. Using CLPT-GSRSD in our analysis of the combined sample of the three redshift bins, we report measurements of $f \\sigma_8$ for the three redshift bins. We find $f \\sigma_8 = 0.430 \\pm 0.054$ at $z_{\\rm eff} = 0.38$, $f \\sigma_8 = 0.452 \\pm 0.057$ at $z_{\\rm eff} = 0.51$ and $f \\sigma_8 = 0.457 \\pm 0.052$ at $z_{\\rm eff} = 0.61$. Our results are consistent with the predictions of Planck $\\Lambda$CDM-GR. Our constraints on the growth rates of structure in the Universe at differ...
Baryon Acoustic Oscillations reconstruction with pixels
Obuljen, Andrej; Castorina, Emanuele; Viel, Matteo
2016-01-01
Gravitational non-linear evolution induces a shift in the position of the baryon acoustic oscillations (BAO) peak together with a damping and broadening of its shape that bias and degrades the accuracy with which the position of the peak can be determined. BAO reconstruction is a technique developed to undo part of the effect of non-linearities. We present a new reconstruction method that consists in displacing pixels instead of galaxies and whose implementation is easier than the standard reconstruction method. We show that our method is equivalent to the standard reconstruction technique in the limit where the number of pixels becomes very large. This method is particularly useful in surveys where individual galaxies are not resolved, as in 21cm intensity mapping observations. We validate our method by reconstructing mock pixelated maps, that we build from the distribution of matter and halos in real- and redshift-space, from a large set of numerical simulations. We find that our method is able to decrease ...
Supersonic Relative Velocity Effect on the Baryonic Acoustic Oscillation Measurements
Yoo, Jaiyul; Seljak, Uros
2011-01-01
We investigate the effect of supersonic relative velocities between baryons and dark matter, recently shown to arise generically at high redshift, on baryonic acoustic oscillation (BAO) measurements at low redshift. The amplitude of the relative velocity effect at low redshift is model-dependent, but can be parameterized by using an unknown bias. We find that if unaccounted, the relative velocity effect can shift the BAO peak position and bias estimates of the dark energy equation-of-state due to its non-smooth, out-of-phase oscillation structure around the BAO scale. Fortunately, the relative velocity effect can be easily modeled in constraining cosmological parameters without substantially inflating the error budget. We also demonstrate that the presence of the relative velocity effect gives rise to a unique signature in the galaxy bispectrum, which can be utilized to isolate this effect. Future dark energy surveys can accurately measure the relative velocity effect and subtract it from the power spectrum a...
Rodríguez-Torres, Sergio A; Chuang, Chia-Hsun; Guo, Hong; Klypin, Anatoly; Behroozi, Peter; Hahn, Chang Hoon; Comparat, Johan; Yepes, Gustavo; Montero-Dorta, Antonio D; Brownstein, Joel R; Maraston, Claudia; McBride, Cameron K; Tinker, Jeremy; Gottlöber, Stefan; Favole, Ginevra; Shu, Yiping; Kitaura, Francisco-Shu; Bolton, Adam; Scoccimarro, Román; Samushia, Lado; Schlegel, David; Schneider, Donald P; Thomas, Daniel
2015-01-01
We present a study of the clustering and halo occupation distribution of BOSS CMASS galaxies in the redshift range 0.43 < z < 0.7 drawn from the Final SDSS-III Data Release. We compare the BOSS results with the predictions of a halo abundance matching (HAM) clustering model that assigns galaxies to dark matter halos selected from the large BigMultiDark N-body simulation of a flat $\\Lambda$CDM Planck cosmology. We compare the observational data with the simulated ones on a light-cone constructed from 20 subsequent outputs of the simulation. Observational effects such as incompleteness, geometry, veto masks and fiber collisions are included in the model, which reproduces within 1-$\\sigma$ errors the observed monopole of the 2-point correlation function at all relevant scales{: --} from the smallest scales, 0.5 $h^{-1}$Mpc , up to scales beyond the Baryonic Acoustic Oscillation feature. This model also agrees remarkably well with the BOSS galaxy power spectrum (up to $k\\sim1$ $h$ Mpc$^{-1}$), and the three...
Baryon Acoustic Oscillation Intensity Mapping of Dark Energy
Chang, Tzu-Ching; Pen, Ue-Li; Peterson, Jeffrey B.; McDonald, Patrick
2008-03-01
The expansion of the Universe appears to be accelerating, and the mysterious antigravity agent of this acceleration has been called “dark energy.” To measure the dynamics of dark energy, baryon acoustic oscillations (BAO) can be used. Previous discussions of the BAO dark energy test have focused on direct measurements of redshifts of as many as 109 individual galaxies, by observing the 21 cm line or by detecting optical emission. Here we show how the study of acoustic oscillation in the 21 cm brightness can be accomplished by economical three-dimensional intensity mapping. If our estimates gain acceptance they may be the starting point for a new class of dark energy experiments dedicated to large angular scale mapping of the radio sky, shedding light on dark energy.
Efficient Reconstruction of Linear Baryon Acoustic Oscillations in Galaxy Surveys
Burden, Angela; Manera, Marc; Cuesta, Antonio J; Magana, Mariana Vargas; Ho, Shirley
2014-01-01
Reconstructing an estimate of linear Baryon Acoustic Oscillations (BAO) from an evolved galaxy field has become a standard technique in recent analyses. By partially removing non-linear damping caused by bulk motions, the real-space BAO peak in the correlation function is sharpened, and oscillations in the power spectrum are visible to smaller scales. In turn these lead to stronger measurements of the BAO scale. Future surveys are being designed assuming that this improvement has been applied, and this technique is therefore of critical importance for future BAO measurements. A number of reconstruction techniques are available, but the most widely used is a simple algorithm that decorrelates large-scale and small-scale modes approximately removing the bulk-flow displacements by moving the overdensity field (Eisenstein et al. 2007; Padmanabhan, White & Cohn 2009). We consider the practical implementation of this algorithm, looking at the efficiency of reconstruction as a function of the assumptions made fo...
Streaming Velocities and the Baryon Acoustic Oscillation Scale.
Blazek, Jonathan A; McEwen, Joseph E; Hirata, Christopher M
2016-03-25
At the epoch of decoupling, cosmic baryons had supersonic velocities relative to the dark matter that were coherent on large scales. These velocities subsequently slow the growth of small-scale structure and, via feedback processes, can influence the formation of larger galaxies. We examine the effect of streaming velocities on the galaxy correlation function, including all leading-order contributions for the first time. We find that the impact on the baryon acoustic oscillation (BAO) peak is dramatically enhanced (by a factor of ∼5) over the results of previous investigations, with the primary new effect due to advection: if a galaxy retains memory of the primordial streaming velocity, it does so at its Lagrangian, rather than Eulerian, position. Since correlations in the streaming velocity change rapidly at the BAO scale, this advection term can cause a significant shift in the observed BAO position. If streaming velocities impact tracer density at the 1% level, compared to the linear bias, the recovered BAO scale is shifted by approximately 0.5%. This new effect, which is required to preserve Galilean invariance, greatly increases the importance of including streaming velocities in the analysis of upcoming BAO measurements and opens a new window to the astrophysics of galaxy formation.
Quasar-Lyman $\\alpha$ Forest Cross-Correlation from BOSS DR11 : Baryon Acoustic Oscillations
Font-Ribera, Andreu; Busca, Nicolas; Miralda-Escudé, Jordi; Ross, Nicholas P; Slosar, Anže; Aubourg, Éric; Bailey, Stephen; Bhardwaj, Vaishali; Bautista, Julian; Beutler, Florian; Bizyaev, Dmitry; Blomqvist, Michael; Brewington, Howard; Brinkmann, Jon; Brownstein, Joel R; Carithers, Bill; Dawson, Kyle S; Delubac, Timothée; Ebelke, Garrett; Eisenstein, Daniel J; Ge, Jian; Kinemuchi, Karen; Lee, Khee-Gan; Malanushenko, Viktor; Malanushenko, Elena; Marchante, Moses; Margala, Daniel; Muna, Demitri; Myers, Adam D; Noterdaeme, Pasquier; Oravetz, Daniel; Palanque-Delabrouille, Nathalie; Pâris, Isabelle; Petitjean, Patrick; Pieri, Matthew M; Rossi, Graziano; Schneider, Donald P; Simmons, Audrey; Viel, Matteo; Yeche, Christophe; York, Donald G
2013-01-01
We measure the large-scale cross-correlation of quasars with the Lyman alpha forest absorption, using over 164,000 quasars from Data Release 11 of the SDSS-III Baryon Oscillation Spectroscopic Survey. We extend the previous study of roughly 60,000 quasars from Data Release 9 to larger separations, allowing a measurement of the Baryonic Acoustic Oscillation (BAO) scale along the line of sight $c/(H(z=2.36) ~ r_s) = 9.0 \\pm 0.3$ and across the line of sight $D_A(z=2.36)~ / ~ r_s = 10.8 \\pm 0.4$, consistent with CMB and other BAO data. Using the best fit value of the sound horizon from Planck data ($r_s=147.49 Mpc$), we can translate these results to a measurement of the Hubble parameter of $H(z=2.36) = 226 \\pm 8 km/s$ and of the angular diameter distance of $D_A(z=2.36) = 1590 \\pm 60 Mpc$. The measured cross-correlation function and an update of the code to fit the BAO scale (baofit) are made publicly available.
The BOSS-WiggleZ overlap region I: Baryon Acoustic Oscillations
Beutler, Florian; Koda, Jun; Marin, Felipe; Seo, Hee-Jong; Cuesta, Antonio J; Schneider, Donald P
2015-01-01
We study the large-scale clustering of galaxies in the overlap region of the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS sample and the WiggleZ Dark Energy Survey. We calculate the auto-correlation and cross-correlation functions in the overlap region of the two datasets and detect a Baryon Acoustic Oscillation (BAO) signal in each of them. The BAO measurement from the cross-correlation function represents the first such detection between two different galaxy surveys. After applying density-field reconstruction we report distance-scale measurements $D_V r_s^{\\rm fid} / r_s = (1970 \\pm 47, 2132 \\pm 67, 2100 \\pm 200)$ Mpc from CMASS, the cross-correlation and WiggleZ, respectively. We use correlated mock realizations to calculate the covariance between the three BAO constraints. The distance scales derived from the two datasets are consistent, and are also robust against switching the displacement fields used for reconstruction between the two surveys. This approach can be used to construct a correlati...
The BOSS-WiggleZ overlap region - I. Baryon acoustic oscillations
Beutler, Florian; Blake, Chris; Koda, Jun; Marín, Felipe A.; Seo, Hee-Jong; Cuesta, Antonio J.; Schneider, Donald P.
2016-01-01
We study the large-scale clustering of galaxies in the overlap region of the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS sample and the WiggleZ Dark Energy Survey. We calculate the auto-correlation and cross-correlation functions in the overlap region of the two data sets and detect a Baryon Acoustic Oscillation (BAO) signal in each of them. The BAO measurement from the cross-correlation function represents the first such detection between two different galaxy surveys. After applying density-field reconstruction we report distance-scale measurements D_V r_s^fid / r_s = (1970 ± 45, 2132 ± 65, 2100 ± 200) Mpc from CMASS, the cross-correlation and WiggleZ, respectively. The distance scales derived from the two data sets are consistent, and are also robust against switching the displacement fields used for reconstruction between the two surveys. We use correlated mock realizations to calculate the covariance between the three BAO constraints. This approach can be used to construct a correlation matrix, permitting for the first time a rigorous combination of WiggleZ and CMASS BAO measurements. Using a volume-scaling technique, our result can also be used to combine WiggleZ and future CMASS DR12 results. Finally, we show that the relative velocity effect, a possible source of systematic uncertainty for the BAO technique, is consistent with zero for our samples.
Redshift Weights for Baryon Acoustic Oscillations : Application to Mock Galaxy Catalogs
Zhu, Fangzhou; White, Martin; Ross, Ashley J; Zhao, Gongbo
2016-01-01
Large redshift surveys capable of measuring the Baryon Acoustic Oscillation (BAO) signal have proven to be an effective way of measuring the distance-redshift relation in cosmology. Building off the work in Zhu et al. (2015), we develop a technique to directly constrain the distance-redshift relation from BAO measurements without splitting the sample into redshift bins. We parametrize the distance-redshift relation, relative to a fiducial model, as a quadratic expansion. We measure its coefficients and reconstruct the distance-redshift relation from the expansion. We apply the redshift weighting technique in Zhu et al. (2015) to the clustering of galaxies from 1000 QuickPM (QPM) mock simulations after reconstruction and achieve a 0.75% measurement of the angular diameter distance $D_A$ at $z=0.64$ and the same precision for Hubble parameter H at $z=0.29$. These QPM mock catalogs are designed to mimic the clustering and noise level of the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12). W...
Measuring the distance-redshift relation with the baryon acoustic oscillations of galaxy clusters
Veropalumbo, Alfonso; Moscardini, Lauro; Moresco, Michele; Cimatti, Andrea
2015-01-01
We analyse the largest spectroscopic samples of galaxy clusters to date, and provide observational constraints on the distance-redshift relation from baryon acoustic oscillations. The cluster samples considered in this work have been extracted from the Sloan Digital Sky Survey at three median redshifts, $z=0.2$, $z=0.3$, and $z=0.5$. The number of objects is $12910$, $42215$, and $11816$, respectively. We detect the peak of baryon acoustic oscillations for all the three samples. The derived distance constraints are: $r_s/D_V(z=0.2)=0.18 \\pm 0.01$, $r_s/D_V(z=0.3)=0.124 \\pm 0.004$ and $r_s/D_V(z=0.5)=0.080 \\pm 0.002$. Combining these measurements, we obtain robust constraints on cosmological parameters. Our results are in agreement with the standard $\\Lambda$ cold dark matter model. Specifically, we constrain the Hubble constant in a $\\Lambda$CDM model, $H_0 = 64_{-9}^{+14} \\, \\mathrm{km} \\, \\mathrm{s}^{-1}\\mathrm{Mpc}^{-1}$, the density of curvature energy, in the $o\\Lambda$CDM context, $\\Omega_K = -0.015_{-0...
Baryon Acoustic Oscillations in the Ly{\\alpha} forest of BOSS DR11 quasars
Delubac, Timothée; Busca, Nicolás G; Rich, James; Kirkby, David; Bailey, Stephen; Font-Ribera, Andreu; Slosar, Anže; Lee, Khee-Gan; Pieri, Matthew M; Hamilton, Jean-Christophe; Aubourg, Éric; Blomqvist, Michael; Bovy, Jo; Brinkmann, J; Carithers, William; Dawson, Kyle S; Eisenstein, Daniel J; Kneib, Jean-Paul; Goff, J -M Le; Margala, Daniel; Miralda-Escudé, Jordi; Myers, Adam D; Nichol, Robert C; Noterdaeme, Pasquier; O'Connell, Ross; Olmstead, Matthew D; Palanque-Delabrouille, Nathalie; Pâris, Isabelle; Petitjean, Patrick; Ross, Nicholas P; Rossi, Graziano; Schlegel, David J; Schneider, Donald P; Weinberg, David H; Yèche, Christophe; York, Donald G
2014-01-01
We report a detection of the baryon acoustic oscillation (BAO) feature in the flux-correlation function of the Ly{\\alpha} forest of high-redshift quasars with a statistical significance of five standard deviations. The study uses 137,562 quasars in the redshift range $2.1\\le z \\le 3.5$ from the Data Release 11 (DR11) of the Baryon Oscillation Spectroscopic Survey (BOSS) of SDSS-III. This sample contains three times the number of quasars used in previous studies. The measured position of the BAO peak determines the angular distance, $D_A(z=2.34)$ and expansion rate, $H(z=2.34)$, both on a scale set by the sound horizon at the drag epoch, $r_d$. We find $D_A/r_d=11.28\\pm0.65(1\\sigma)^{+2.8}_{-1.2}(2\\sigma)$ and $D_H/r_d=9.18\\pm0.28(1\\sigma)\\pm0.6(2\\sigma)$ where $D_H=c/H$. The optimal combination, $\\sim D_H^{0.7}D_A^{0.3}/r_d$ is determined with a precision of $\\sim2\\%$. For the value $r_d=147.4~{\\rm Mpc}$, consistent with the CMB power spectrum measured by Planck, we find $D_A(z=2.34)=1662\\pm96(1\\sigma)~{\\rm M...
Measuring the 2D baryon acoustic oscillation signal of galaxies in WiggleZ: cosmological constraints
Hinton, Samuel R.; Kazin, Eyal; Davis, Tamara M.; Blake, Chris; Brough, Sarah; Colless, Matthew; Couch, Warrick J.; Drinkwater, Michael J.; Glazebrook, Karl; Jurek, Russell J.; Parkinson, David; Pimbblet, Kevin A.; Poole, Gregory B.; Pracy, Michael; Woods, David
2017-02-01
We present results from the 2D anisotropic baryon acoustic oscillation (BAO) signal present in the final data set from the WiggleZ Dark Energy Survey. We analyse the WiggleZ data in two ways: first using the full shape of the 2D correlation function and secondly focusing only on the position of the BAO peak in the reconstructed data set. When fitting for the full shape of the 2D correlation function we use a multipole expansion to compare with theory. When we use the reconstructed data we marginalize over the shape and just measure the position of the BAO peak, analysing the data in wedges separating the signal along the line of sight from that parallel to the line of sight. We verify our method with mock data and find the results to be free of bias or systematic offsets. We also redo the pre-reconstruction angle-averaged (1D) WiggleZ BAO analysis with an improved covariance and present an updated result. The final results are presented in the form of Ωc h2, H(z), and DA(z) for three redshift bins with effective redshifts z = 0.44, 0.60, and 0.73. Within these bins and methodologies, we recover constraints between 5 and 22 per cent error. Our cosmological constraints are consistent with flat ΛCDM cosmology and agree with results from the Baryon Oscillation Spectroscopic Survey.
Baryon Acoustic Oscillations in the Ly-\\alpha\\ forest of BOSS quasars
Busca, Nicolás G; Rich, James; Bailey, Stephen; Font-Ribera, Andreu; Kirkby, David; Goff, J -M Le; Pieri, Matthew M; Slosar, Anze; Aubourg, Éric; Bautista, Julian E; Bizyaev, Dmitry; Blomqvist, Michael; Bolton, Adam S; Bovy, Jo; Brewington, Howard; Borde, Arnaud; Brinkmann, J; Carithers, Bill; Croft, Rupert A C; Dawson, Kyle S; Ebelke, Garrett; Eisenstein, Daniel J; Hamilton, Jean-Christophe; Ho, Shirley; Hogg, David W; Honscheid, Klaus; Lee, Khee-Gan; Lundgren, Britt; Malanushenko, Elena; Malanushenko, Viktor; Margala, Daniel; Maraston, Claudia; Mehta, Kushal; Miralda-Escudé, Jordi; Myers, Adam D; Nichol, Robert C; Noterdaeme, Pasquier; Olmstead, Matthew D; Oravetz, Daniel; Palanque-Delabrouille, Nathalie; Pan, Kaike; Pâris, Isabelle; Percival, Will J; Petitjean, Patrick; Roe, N A; Rollinde, Emmanuel; Ross, Nicholas P; Rossi, Graziano; Schlegel, David J; Schneider, Donald P; Shelden, Alaina; Sheldon, Erin S; Simmons, Audrey; Snedden, Stephanie; Tinker, Jeremy L; Viel, Matteo; Weaver, Benjamin A; Weinberg, David H; White, Martin; Yèche, Christophe; York, Donald G; Zhao, Gong-Bo
2012-01-01
We report a detection of the baryon acoustic oscillation (BAO) feature in the three-dimensional correlation function of the transmitted flux fraction in the \\Lya forest of high-redshift quasars. The study uses 48,640 quasars in the redshift range $2.1\\le z \\le 3.5$ from the Baryon Oscillation Spectroscopic Survey (BOSS) of the third generation of the Sloan Digital Sky Survey (SDSS-III). At a mean redshift $z=2.3$, we measure the monopole and quadrupole components of the correlation function for separations in the range $20\\hMpc
The baryon acoustic oscillation peak: a flexible standard ruler
Roukema, Boudewijn F
2016-01-01
For about a decade, the baryon acoustic oscillation (BAO) peak at about 105 Mpc/h has provided a standard ruler test of the LCDM cosmological model, a member of the Friedmann--Lemaitre--Robertson--Walker (FLRW) family of cosmological models---according to which comoving space is rigid. However, general relativity does not require comoving space to be rigid. During the virialisation epoch, when the most massive structures form by gravitational collapse, it should be expected that comoving space evolves inhomogeneous curvature as structure grows. The BAO peak standard ruler should also follow this inhomogeneous evolution if the comoving rigidity assumption is false. This "standard" ruler has now been detected to be flexible, as expected under general relativity.
Baryon Acoustic Oscillations in the Lyman Alpha Forest
Norman, Michael L; Harkness, Robert
2009-01-01
We use hydrodynamic cosmological simulations in a (600 Mpc)^3 volume to study the observability of baryon acoustic oscillations (BAO) in the intergalactic medium as probed by Lyman alpha forest (LAF) absorption. The large scale separation between the wavelength of the BAO mode (~150 Mpc) and the size of LAF absorbers (~100 kpc) makes this a numerically challenging problem. We report on several 2048^3 simulations of the LAF using the ENZO code. We adopt WMAP5 concordance cosmological parameters and power spectrum including BAO perturbations. 5000 synthetic HI absorption line spectra are generated randomly piercing the box face. We calculate the cross-correlation function between widely separated pairs. We detect the BAO signal at z=3 where theory predicts to moderate statistical significance.
Measuring baryon acoustic oscillations with future SKA surveys
Bull, Philip; Raccanelli, Alvise; Blake, Chris; Ferreira, Pedro G; Santos, Mario G; Schwarz, Dominik J
2015-01-01
The imprint of baryon acoustic oscillations (BAO) in large-scale structure can be used as a standard ruler for mapping out the cosmic expansion history, and hence for testing cosmological models. In this article we briefly describe the scientific background to the BAO technique, and forecast the potential of the Phase 1 and 2 SKA telescopes to perform BAO surveys using both galaxy catalogues and intensity mapping, assessing their competitiveness with current and future optical galaxy surveys. We find that a 25,000 sq. deg. intensity mapping survey on a Phase 1 array will preferentially constrain the radial BAO, providing a highly competitive 2% constraint on the expansion rate at z ~ 2. A 30,000 sq. deg. galaxy redshift survey on SKA2 will outperform all other planned experiments for z < 1.4.
Is the baryon acoustic oscillation peak a cosmological standard ruler?
Roukema, Boudewijn F; Fujii, Hirokazu; Ostrowski, Jan J
2016-01-01
In the standard model of cosmology, the Universe is static in comoving coordinates; expansion occurs homogeneously and is represented by a global scale factor. The baryon acoustic oscillation (BAO) peak location is a statistical tracer that represents, in the standard model, a fixed comoving-length standard ruler. Recent gravitational collapse should modify the metric, rendering the effective scale factor, and thus the BAO standard ruler, spatially inhomogeneous. Using the Sloan Digital Sky Survey, we show to high significance (P < 0.001) that the spatial compression of the BAO peak location increases as the spatial paths' overlap with superclusters increases. Detailed observational and theoretical calibration of this BAO peak location environment dependence will be needed when interpreting the next decade's cosmological surveys.
Systematic treatment of non-linear effects in Baryon Acoustic Oscillations
Ivanov, Mikhail M
2016-01-01
In this contribution we will discuss the non-linear effects in the baryon acoustic oscillations and present a systematic and controllable way to account for them within time-sliced perturbation theory.
A New Statistic for Analyzing Baryon Acoustic Oscillations
Xu, X; Padmanabhan, N; Eisenstein, D; Eckel, J; Mehta, K; Metchnik, M; Pinto, P; Seo, H -J
2010-01-01
We introduce a new statistic omega_l for measuring and analyzing large-scale structure and particularly the baryon acoustic oscillations. omega_l is a band-filtered, configuration space statistic that is easily implemented and has advantages over the traditional power spectrum and correlation function estimators. Unlike these estimators, omega_l can localize most of the acoustic information into a single dip at the acoustic scale while also avoiding sensitivity to the poorly constrained large scale power (i.e., the integral constraint) through the use of a localized and compensated filter. It is also sensitive to anisotropic clustering through pair counting and does not require any binning. We measure the shift in the acoustic peak due to nonlinear effects using the monopole omega_0 derived from subsampled dark matter catalogues as well as from mock galaxy catalogues created via halo occupation distribution (HOD) modeling. All of these are drawn from 44 realizations of 1024^3 particle dark matter simulations ...
Non-Gaussian errors of baryonic acoustic oscillations
Ngan, Wai-Hin Wayne; Pen, Ue-Li; McDonald, Patrick; MacDonald, Ilana
2011-01-01
We revisit the uncertainty in baryon acoustic oscillation (BAO) forecasts and data analyses. In particular, we study how much the error on the measured mean and uncertainty on the dilation scale are affected by the non-Gaussianity of the non-linear density field. We examine two possible impacts of non-Gaussian analysis: 1. we derive the distance estimators from Gaussian theory, but use 1000 N-Body simulations to measure the actual errors, and compare this to the Gaussian prediction, and 2. we compute new optimal estimators, which requires the inverse of the non-Gaussian covariance matrix of the matter power spectrum. Obtaining an accurate and precise inversion is challenging, and we opted for a noise reduction technique applied on the covariance matrices. By measuring the bootstrap error on the inverted matrix, this work quantifies for the first time the significance of the non-Gaussian error corrections on the BAO dilation scale. We find that the variance (error squared) on distance measurements can deviate ...
Cosmological implications of two types of baryon acoustic oscillation data
Hu, Yazhou; Li, Nan; Wang, Shuang
2015-01-01
Aims: We explore the cosmological implications of two types of baryon acoustic oscillation (BAO) data that are extracted by using the spherically averaged one-dimensional galaxy clustering (GC) statistics (hereafter BAO1) and the anisotropic two-dimensional GC statistics (hereafter BAO2), respectively. Methods: Firstly, making use of the BAO1 and the BAO2 data, as well as the SNLS3 type Ia supernovae sample and the Planck distance priors data, we constrain the parameter spaces of the $\\Lambda$CDM, the $w$CDM, and the Chevallier-Polarski-Linder (CPL) model. Then, we discuss the impacts of different BAO data on parameter estimation, equation of state $w$, figure of merit and deceleration-acceleration transition redshift. At last, we use various dark energy diagnosis, including Hubble diagram $H(z)$, deceleration diagram $q(z)$, statefinder hierarchy $\\{S^{(1)}_3, S^{(1)}_4\\}$, composite null diagnosic (CND) $\\{S^{(1)}_3, \\epsilon(z)\\}$ and $\\{S^{(1)}_4, \\epsilon(z)\\}$, to distinguish the differences between the...
Cosmological implications of baryon acoustic oscillation (BAO) measurements
Aubourg, Éric; Bautista, Julian E; Beutler, Florian; Bhardwaj, Vaishali; Bizyaev, Dmitry; Blanton, Michael; Blomqvist, Michael; Bolton, Adam S; Bovy, Jo; Brewington, Howard; Brinkmann, J; Brownstein, Joel R; Burden, Angela; Busca, Nicolás G; Carithers, William; Chuang, Chia-Hsun; Comparat, Johan; Cuesta, Antonio J; Dawson, Kyle S; Delubac, Timothée; Eisenstein, Daniel J; Font-Ribera, Andreu; Ge, Jian; Goff, J -M Le; Gontcho, Satya Gontcho A; Gott, J Richard; Gunn, James E; Guo, Hong; Guy, Julien; Hamilton, Jean-Christophe; Ho, Shirley; Honscheid, Klaus; Howlett, Cullan; Kirkby, David; Kitaura, Francisco S; Kneib, Jean-Paul; Lee, Khee-Gan; Long, Dan; Lupton, Robert H; Magaña, Mariana Vargas; Malanushenko, Viktor; Malanushenko, Elena; Manera, Marc; Maraston, Claudia; Margala, Daniel; McBride, Cameron K; Miralda-Escudé, Jordi; Myers, Adam D; Nichol, Robert C; Noterdaeme, Pasquier; Nuza, Sebastián E; Olmstead, Matthew D; Oravetz, Daniel; Pâris, Isabelle; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Pellejero-Ibanez, Marcos; Percival, Will J; Petitjean, Patrick; Pieri, Matthew M; Prada, Francisco; Reid, Beth; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Rossi, Graziano; Rubiño-Martín, Jose Alberto; Sánchez, Ariel G; Samushia, Lado; Santos, Ricardo Tanausú Génova; Scóccola, Claudia G; Schlegel, David J; Schneider, Donald P; Seo, Hee-Jong; Sheldon, Erin; Simmons, Audrey; Skibba, Ramin A; Slosar, Anže; Strauss, Michael A; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Vazquez, Jose Alberto; Viel, Matteo; Wake, David A; Weaver, Benjamin A; Weinberg, David H; Wood-Vasey, W M; Yèche, Christophe; Zehavi, Idit; Zhao, Gong-Bo
2014-01-01
We derive constraints on cosmological parameters and tests of dark energy models from the combination of baryon acoustic oscillation (BAO) measurements with cosmic microwave background (CMB) and Type Ia supernova (SN) data. We take advantage of high-precision BAO measurements from galaxy clustering and the Ly-alpha forest (LyaF) in the BOSS survey of SDSS-III. BAO data alone yield a high confidence detection of dark energy, and in combination with the CMB angular acoustic scale they further imply a nearly flat universe. Combining BAO and SN data into an "inverse distance ladder" yields a 1.7% measurement of $H_0=67.3 \\pm1.1$ km/s/Mpc. This measurement assumes standard pre-recombination physics but is insensitive to assumptions about dark energy or space curvature, so agreement with CMB-based estimates that assume a flat LCDM cosmology is an important corroboration of this minimal cosmological model. For open LCDM, our BAO+SN+CMB combination yields $\\Omega_m=0.301 \\pm 0.008$ and curvature $\\Omega_k=-0.003 \\pm ...
Measuring Baryon Acoustic Oscillations from the clustering of voids
Liang, Yu; Chuang, Chia-Hsun; Kitaura, Francisco-Shu; Tao, Charling
2015-01-01
We investigate the necessary methodology to optimally measure the baryon acoustic oscillation (BAO) signal, from voids based on galaxy redshift catalogues. To this end, we study the dependency of the BAO signal on the population of voids classified by their sizes. We find for the first time the characteristic features of the correlation function of voids including the first robust detection of BAOs in mock galaxy catalogues. These show an anti-correlation around the scale corresponding to the smallest size of voids in the sample (the void exclusion effect), and dips at both sides of the BAO peak, which can be used to determine the significance of the BAO signal without any priori model. Furthermore, our analysis demonstrates that there is a scale dependent bias for different populations of voids depending on the radius, with the peculiar property that the void population with the largest BAO significance corresponds to tracers with approximately zero bias on the largest scales. We further investigate the meth...
Impact of finite density on spectroscopic parameters of decuplet baryons
Azizi, K; Sundu, H
2016-01-01
The decuplet baryons, $\\Delta$, $\\Sigma^{*}$, $\\Xi^{*}$ and $\\Omega^{-}$, are studied in nuclear matter by using the in-medium QCD sum rules. By fixing the three momentum of the particles under consideration at the rest frame of the medium, the negative energy contributions are removed. It is obtained that the parameters of the $\\Delta$ baryon are more affected by the medium against the $\\Omega^{-}$ state, containing three strange quarks, whose mass and residue do not affected by the medium, considerably. We also find the vector and scalar self energies of these baryons in nuclear matter. By the recent progresses at $\\bar{P}$ANDA experiment at FAIR it may be possible to study the in-medium properties of such states even the multi-strange $\\Xi^{*}$ and $\\Omega^{-}$ systems in near future.
The Alcock Paczy'nski test with Baryon Acoustic Oscillations: systematic effects for future surveys
Lepori, Francesca; Di Dio, Enea; Viel, Matteo; Baccigalupi, Carlo; Durrer, Ruth
2017-02-01
We investigate the Alcock Paczy'nski (AP) test applied to the Baryon Acoustic Oscillation (BAO) feature in the galaxy correlation function. By using a general formalism that includes relativistic effects, we quantify the importance of the linear redshift space distortions and gravitational lensing corrections to the galaxy number density fluctuation. We show that redshift space distortions significantly affect the shape of the correlation function, both in radial and transverse directions, causing different values of galaxy bias to induce offsets up to 1% in the AP test. On the other hand, we find that the lensing correction around the BAO scale modifies the amplitude but not the shape of the correlation function and therefore does not introduce any systematic effect. Furthermore, we investigate in details how the AP test is sensitive to redshift binning: a window function in transverse direction suppresses correlations and shifts the peak position toward smaller angular scales. We determine the correction that should be applied in order to account for this effect, when performing the test with data from three future planned galaxy redshift surveys: Euclid, the Dark Energy Spectroscopic Instrument (DESI) and the Square Kilometer Array (SKA).
Babu, K S
2016-01-01
We point out that if the baryon number violating neutron-antineutron oscillation is discovered, it would impose strong limits on the departure from Einstein's equivalence principle at a level of one part in $10^{19}$. If this departure owes its origin to the existence of long-range forces coupled to baryon number $B$ (or $B-L$), it would imply very stringent constraints on the strength of gauge bosons coupling to baryon number current. For instance, if the force mediating baryon number has strength $\\alpha_B$ and its range is larger than a megaparsec, we find the limit to be $\\alpha_B \\leq 2\\times 10^{-57}$, which is much stronger than all other existing bounds. For smaller range for the force, we get slightly weaker, but still stringent bounds by considering the potential of the Earth and the Sun.
Directory of Open Access Journals (Sweden)
Nasrin Salehi
2016-01-01
Full Text Available The spectrum of ground state and excited baryons (N, Δ, Λ, Σ, Ξ, and Ω particles has been investigated by using nonrelativistic quantum mechanics under the Killingbeck plus isotonic oscillator potentials. Using the Jacobi coordinates, anzast method, and generalized Gürsey Radicati (GR mass formula the three-body-wave equation is solved to calculate the different states of the considered baryons. A comparison between our calculations and the available experimental data shows that the position of the Roper resonances of the nucleon, the ground states, and the excited multiplets up to three GeV are in general well reproduced. Also one can conclude that the interaction between the quark constituents of baryon resonances could be described adequately by using the combination of Killingbeck and isotonic oscillator potentials form.
Sumiyoshi, Masanao; Oshige, Shunsuke; Glazebrook, Karl; Akiyama, Masayuki; Morokuma, Tomoki; Motohara, Kentaro; Shimasaku, Kazuhiro; Hayashi, Masao; Yoshida, Makiko; Kashikawa, Nobunari; Kodama, Tadayuki
2009-01-01
Efficient selection of emission line galaxies at z > 1 by photometric information in wide field surveys is one of the keys for future spectroscopic surveys to constrain dark energy using the baryon acoustic oscillation (BAO) signature. Here we estimate the H alpha and [O II] line luminosity functions of galaxies at z = 0.5-1.7 using a novel approach where multi-wavelength imaging data is used to jointly estimate both photometric redshifts and star-formation rates. These photometric estimates of line luminosities at high-redshift use the large data sets of the Subaru Deep Field and Subaru XMM-Newton Deep Field (covering \\sim 1 deg^2) and are calibrated with the spectroscopic data of the local Sloan Digital Sky Survey galaxies. The derived luminosity functions (especially H alpha) are in reasonable agreement with the past estimates based on spectroscopic or narrow-band-filter surveys. This dataset is useful for examining the photometric selection of target galaxies for BAO surveys because of the large cosmologi...
Time-Sliced Perturbation Theory II: Baryon Acoustic Oscillations and Infrared Resummation
Blas, Diego; Ivanov, Mikhail M; Sibiryakov, Sergey
2016-01-01
We use time-sliced perturbation theory (TSPT) to give an accurate description of the infrared non-linear effects affecting the baryonic acoustic oscillations (BAO) present in the distribution of matter at very large scales. In TSPT this can be done via a systematic resummation that has a simple diagrammatic representation and does not involve uncontrollable approximations. We discuss the power counting rules and derive explicit expressions for the resummed matter power spectrum up to next-to leading order and the bispectrum at the leading order. The two-point correlation function agrees well with N-body data at BAO scales. The systematic approach also allows to reliably assess the shift of the baryon acoustic peak due to non-linear effects.
Simulations of Baryon Acoustic Oscillations I: Growth of Large-Scale Density Fluctuations
Takahashi, Ryuichi; Matsubara, Takahiko; Sugiyama, Naoshi; Kayo, Issha; Nishimichi, Takahiro; Shirata, Akihito; Taruya, Atsushi; Saito, Shun; Yahata, Kazuhiro; Suto, Yasushi
2008-01-01
We critically examine how well the evolution of large-scale density perturbations is followed in cosmological $N$-body simulations. We first run a large volume simulation and perform a mode-by-mode analysis in three-dimensional Fourier space. We show that the growth of large-scale fluctuations significantly deviates from linear theory predictions. The deviations are caused by {\\it nonlinear} coupling with a small number of modes at largest scales owing to finiteness of the simulation volume. We then develop an analytic model based on second-order perturbation theory to quantify the effect. Our model accurately reproduces the simulation results. For a single realization, the second-order effect appears typically as ``zig-zag'' patterns around the linear-theory prediction, which imprints artificial ``oscillations'' that lie on the real baryon-acoustic oscillations. Although an ensemble average of a number of realizations approaches the linear theory prediction, the dispersions of the realizations remain large e...
Pober, Jonathan C; DeBoer, David R; McDonald, Patrick; McQuinn, Matthew; Aguirre, James E; Ali, Zaki; Bradley, Richard F; Chang, Tzu-Ching; Morales, Miguel F
2012-01-01
This work describes a new instrument optimized for a detection of the neutral hydrogen 21cm power spectrum between redshifts of 0.5-1.5: the Baryon Acoustic Oscillation Broadband and Broad-beam (BAOBAB) Array. BAOBAB will build on the efforts of a first generation of 21cm experiments which are targeting a detection of the signal from the Epoch of Reionization at z ~ 10. At z ~ 1, the emission from neutral hydrogen in self-shielded overdense halos also presents an accessible signal, since the dominant, synchrotron foreground emission is considerably fainter than at redshift 10. The principle science driver for these observations are Baryon Acoustic Oscillations in the matter power spectrum which have the potential to act as a standard ruler and constrain the nature of dark energy. BAOBAB will fully correlate dual-polarization antenna tiles over the 600-900MHz band with a frequency resolution of 300 kHz and a system temperature of 50K. The number of antennas will grow in staged deployments, and reconfigurations...
Hütsi, Gert; Kolodzig, Alexander; Sunyaev, Rashid
2014-01-01
We investigate the potential of large X-ray selected AGN samples for detecting baryonic acoustic oscillations (BAO). Though AGN selection in X-ray band is very clean and efficient, it does not provide us redshift information, and thus needs to be complemented with an optical follow-up. The main focus of this study is: (i) to find necessary requirements to the quality of the optical follow-up and (ii) to formulate the optimal strategy of the X-ray survey, in order to detect the BAO. We demonstrate that redshift accuracy of sigma_0=10^{-2} and the catastrophic failure rate of <~30% are sufficient for a reliable detection of BAO in future X-ray surveys. Spectroscopic quality redshifts combined with negligible fraction of catastrophic failures will boost the confidence level of the BAO detection by a factor of ~2. For the meaningful detection of BAO, X-ray surveys of moderate depth of F_lim ~ few 10^{-15} erg/s/cm^2 covering sky area from a ~few hundred to ~ten thousand square degrees are required. The optimal...
Baryon oscillations in galaxy and matter power-spectrum covariance matrices
Neyrinck, Mark C
2007-01-01
We investigate large-amplitude baryon acoustic oscillations (BAO's) in off-diagonal entries of cosmological power-spectrum covariance matrices. These covariance-matrix BAO's describe the increased attenuation of power-spectrum BAO's caused by upward fluctuations in large-scale power. We derive an analytic approximation to covariance-matrix entries in the BAO regime, and check the analytical predictions using N-body simulations. These BAO's look much stronger than the BAO's in the power spectrum, but seem detectable only at about a one-sigma level in gigaparsec-scale galaxy surveys. In estimating cosmological parameters using matter or galaxy power spectra, including the covariance-matrix BAO's can have a several-percent effect on error-bar widths for some parameters directly related to the BAO's, such as the baryon fraction. Also, we find that including the numerous galaxies in small haloes in a survey can reduce error bars in these cosmological parameters more than the simple reduction in shot noise might su...
A CROSS-CHECK FOR H0 FROM LYMAN- α FOREST AND BARYON ACOUSTIC OSCILLATIONS
Directory of Open Access Journals (Sweden)
V. C. Busti
2016-01-01
Full Text Available A new method is proposed to infer the Hubble constant H0 through the observed mean transmitted flux from high-redshift quasars and the baryon acoustic oscillations (BAOs. A semi-analytical model for the cosmological-independent volume density distribution function was adopted; it allowed us to obtain constraints on the cosmological parameters once a moderate knowledge of the Inter Galactic Medium (IGM parameters is assumed. Our analysis, based on two different samples of Lyman-α forest and the BAO measurement, restricts (h, Ωm to the intervals 0.19 ≤ Ωm ≤ 0.23 and 0.53 ≤ h ≤ 0.82 (1σ. Although the constraints are weaker compared with other estimates, we point out that, with a bigger sample and a better knowledge of the IGM, this method could provide complementary results to measure the Hubble constant independently of the cosmic distance ladder.
Baryon Acoustic Oscillations in 2D: Modeling Redshift-space Power Spectrum from Perturbation Theory
Taruya, Atsushi; Saito, Shun
2010-01-01
We present an improved prescription for matter power spectrum in redshift space taking a proper account of both the non-linear gravitational clustering and redshift distortion, which are of particular importance for accurately modeling baryon acoustic oscillations (BAOs). Contrary to the models of redshift distortion phenomenologically introduced but frequently used in the literature, the new model includes the corrections arising from the non-linear coupling between the density and velocity fields associated with two competitive effects of redshift distortion, i.e., Kaiser and Finger-of-God effects. Based on the improved treatment of perturbation theory for gravitational clustering, we compare our model predictions with monopole and quadrupole power spectra of N-body simulations, and an excellent agreement is achieved over the scales of BAOs. Potential impacts on constraining dark energy and modified gravity from the redshift-space power spectrum are also investigated based on the Fisher-matrix formalism. We...
Measuring baryon acoustic oscillations with angular two-point correlation function
Alcaniz, Jailson S; Bernui, Armando; Carvalho, Joel C; Benetti, Micol
2016-01-01
The Baryon Acoustic Oscillations (BAO) imprinted a characteristic correlation length in the large-scale structure of the universe that can be used as a standard ruler for mapping out the cosmic expansion history. Here, we discuss the application of the angular two-point correlation function, $w(\\theta)$, to a sample of luminous red galaxies of the Sloan Digital Sky Survey (SDSS) and derive two new measurements of the BAO angular scale at $z = 0.235$ and $z = 0.365$. Since noise and systematics may hinder the identification of the BAO signature in the $w - \\theta$ plane, we also introduce a potential new method to localize the acoustic bump in a model-independent way. We use these new measurements along with previous data to constrain cosmological parameters of dark energy models and to derive a new estimate of the acoustic scale $r_s$.
Ma, Cong
2016-01-01
We use cosmological luminosity distance ($d_L$) from the JLA Type Ia supernovae compilation and angular-diameter distance ($d_A$) based on BOSS and WiggleZ baryon acoustic oscillation measurements to test the distance-duality relation $\\eta \\equiv d_L / [ (1 + z)^2 d_A ] = 1$. The $d_L$ measurements are matched to $d_A$ redshift by a statistically-motivated compression procedure. By means of Monte Carlo methods, non-trivial and correlated distributions of $\\eta$ can be explored in a straightforward manner without resorting to a particular evolution template $\\eta(z)$. Assuming Planck cosmological parameter uncertainty, we find 5% constraints in favor of $\\eta = 1$, consistent with the weaker 7--10% constraints obtained using WiggleZ data. These results stand in contrast to previous claims that $\\eta < 1$ has been found close to or above $1\\sigma$ level.
Xu, Lixin
2012-01-01
In this paper, the holographic dark energy (HDE) model, where the future event horizon is taken as an IR cut-off, is confronted by using currently available cosmic observational data sets which include type Ia supernovae, baryon acoustic oscillation and cosmic microwave background radiation from full information of WMAP-7yr. Via the Markov Chain Monte Carlo method, we obtain the values of model parameter $c= 0.696_{- 0.0737- 0.132- 0.190}^{+ 0.0736+ 0.159+ 0.264}$ with $1,2,3\\sigma$ regions. Therefore one can conclude that at lest $3\\sigma$ level the future Universe will be dominated by phantom like dark energy. It is not consistent with positive energy condition, however this condition must be satisfied to derive the holographic bound. It implies that the current cosmic observational data points disfavor the HDE model.
A cross-check for H0 from Lyman-α Forest and Baryon Acoustic Oscillations
Busti, V. C.; Guimarães, R. N.; Lima, J. A. S.
2016-04-01
A new method is proposed to infer the Hubble constant H0 through the observed mean transmitted flux from high-redshift quasars and the baryon acoustic oscillations (BAOs). A semi-analytical model for the cosmological-independent volume density distribution function was adopted; it allowed us to obtain constraints on the cosmological parameters once a moderate knowledge of the Inter Galactic Medium (IGM) parameters is assumed. Our analysis, based on two different samples of Lyman-α forest and the BAO measurement, restricts (h, Ωm) to the intervals 0.19 ≤ Ωm ≤ 0.23 and 0.53 ≤ h ≤ 0.82 (1σ). Although the constraints are weaker compared with other estimates, we point out that, with a bigger sample and a better knowledge of the IGM, this method could provide complementary results to measure the Hubble constant independently of the cosmic distance ladder.
Energy Technology Data Exchange (ETDEWEB)
Pober, Jonathan C.; Parsons, Aaron R.; McQuinn, Matthew; Ali, Zaki [Astronomy Department, University of California, Berkeley, CA (United States); DeBoer, David R. [Radio Astronomy Laboratory, University of California, Berkeley, CA (United States); McDonald, Patrick [Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Aguirre, James E. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA (United States); Bradley, Richard F. [Astronomy Department and Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA (United States); Chang, Tzu-Ching [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan (China); Morales, Miguel F. [Department of Physics, University of Washington, Seattle, WA (United States)
2013-03-15
This work describes a new instrument optimized for a detection of the neutral hydrogen 21 cm power spectrum between redshifts of 0.5 and 1.5: the Baryon Acoustic Oscillation Broadband and Broad-beam (BAOBAB) array. BAOBAB will build on the efforts of a first generation of 21 cm experiments that are targeting a detection of the signal from the Epoch of Reionization at z {approx} 10. At z {approx} 1, the emission from neutral hydrogen in self-shielded overdense halos also presents an accessible signal, since the dominant, synchrotron foreground emission is considerably fainter than at redshift 10. The principle science driver for these observations are baryon acoustic oscillations in the matter power spectrum which have the potential to act as a standard ruler and constrain the nature of dark energy. BAOBAB will fully correlate dual-polarization antenna tiles over the 600-900 MHz band with a frequency resolution of 300 kHz and a system temperature of 50 K. The number of antennas will grow in staged deployments, and reconfigurations of the array will allow for both traditional imaging and high power spectrum sensitivity operations. We present calculations of the power spectrum sensitivity for various array sizes, with a 35 element array measuring the cosmic neutral hydrogen fraction as a function of redshift, and a 132 element system detecting the BAO features in the power spectrum, yielding a 1.8% error on the z {approx} 1 distance scale, and, in turn, significant improvements to constraints on the dark energy equation of state over an unprecedented range of redshifts from {approx}0.5 to 1.5.
Future prospects of baryon istability search in p-decay and n n(bar) oscillation experiments
Energy Technology Data Exchange (ETDEWEB)
Ball, S.J.; Kamyshkov, Y.A. [ed.
1996-11-01
These proceedings contain thirty-one papers which review both the theoretical and the experimental status and near future of baryon instability research. Baryon instability is investigated from the vantage point of supersymmetric and unified theories. The interplay between baryogenesis and antimatter is examined. Double beta decay experiments are discussed. The huge Icarus experiment is described with its proton decay capabilities. Neutron-antineutron oscillations investigations are presented, especially efforts with ultra-cold neutrons. Individual papers are indexed separately on the Energy Data Base.
Probing Dark Energy with Baryonic Acoustic Oscillations from Future Large Galaxy Redshift Surveys
Eisenstein, D J
2003-01-01
We show that the measurement of the baryonic acoustic oscillations in large high redshift galaxy surveys offers a precision route to the measurement of dark energy. The cosmic microwave background provides the scale of the oscillations as a standard ruler that can be measured in the clustering of galaxies, thereby yielding the Hubble parameter and angular diameter distance as a function of redshift. This, in turn, enables one to probe dark energy. We use a Fisher matrix formalism to study the statistical errors for redshift surveys up to z=3 and report errors on cosmography while marginalizing over a large number of cosmological parameters including a time-dependent equation of state. With redshifts surveys combined with cosmic microwave background satellite data, we achieve errors of 0.037 on Omega_x, 0.10 on w(z=0.8), and 0.28 on dw(z)/dz for cosmological constant model. Models with less negative w(z) permit tighter constraints. We test and discuss the dependence of performance on redshift, survey condition...
Model independent evidence for dark energy evolution from Baryon Acoustic Oscillations
Sahni, Varun; Starobinsky, Alexei A
2014-01-01
Baryon Acoustic Oscillations (BAO) allow us to determine the expansion history of the Universe, thereby shedding light on the nature of dark energy. Recent observations of BAO's in the SDSS DR9 and DR11 have provided us with statistically independent measurements of $H(z)$ at redshifts of 0.57 and 2.34, respectively. We show that these measurements can be used to test the cosmological constant hypothesis in a model independent manner by means of an improved version of the $Om$ diagnostic. Our results indicate that the SDSS DR11 measurement of $H(z) = 222 \\pm 7$ km/sec/Mpc at $z = 2.34$, when taken in tandem with measurements of $H(z)$ at lower redshifts, imply considerable tension with the standard $\\Lambda$CDM model. Our estimation of the new diagnostic $Omh^2$ from SDSS DR9 and DR11 data, namely $Omh^2 \\approx 0.122 \\pm 0.01$, which is equivalent to $\\Omega_{0m}h^2$ for the spatially flat $\\Lambda$CDM model, is in tension with the value $\\Omega_{0m}h^2 = 0.1426 \\pm 0.0025$ determined for $\\Lambda$CDM from P...
A detection of Baryon Acoustic Oscillations from the distribution of galaxy clusters
Hong, Tao; Wen, Z L
2015-01-01
We calculate the correlation function of 79,091 galaxy clusters in the redshift region of $0.05 \\leq z \\leq 0.5$ selected from the WH15 cluster catalog. With a weight of cluster mass, a significant baryon acoustic oscillation (BAO) peak is detected on the correlation function with a significance of $3.9 \\sigma$. By fitting the correlation function with a $\\Lambda$CDM model curve, we find $D_v(z = 0.331) r_d^{fid}/r_d = 1269.4 \\pm 58$ Mpc which is consistent with the Planck 2015 cosmology. We find that the correlation functions of the higher mass sub-samples show a higher amplitude at small scales of $r < 80~h^{-1}{\\rm Mpc}$, which is consistent with our precious result. We find a clear signal of the `Finger-of-God' effect on the 2D correlation function of the whole sample, which indicates the random peculiar motion of central bright galaxies in the gravitation potential well of clusters.
Simulations of Baryon Acoustic Oscillations II: Covariance matrix of the matter power spectrum
Takahashi, Ryuichi; Takada, Masahiro; Matsubara, Takahiko; Sugiyama, Naoshi; Kayo, Issha; Nishizawa, Atsushi J; Nishimichi, Takahiro; Saito, Shun; Taruya, Atsushi
2009-01-01
We use 5000 cosmological N-body simulations of 1(Gpc/h)^3 box for the concordance LCDM model in order to study the sampling variances of nonlinear matter power spectrum. We show that the non-Gaussian errors can be important even on large length scales relevant for baryon acoustic oscillations (BAO). Our findings are (1) the non-Gaussian errors degrade the cumulative signal-to-noise ratios (S/N) for the power spectrum amplitude by up to a factor of 2 and 4 for redshifts z=1 and 0, respectively. (2) There is little information on the power spectrum amplitudes in the quasi-nonlinear regime, confirming the previous results. (3) The distribution of power spectrum estimators at BAO scales, among the realizations, is well approximated by a Gaussian distribution with variance that is given by the diagonal covariance component. (4) For the redshift-space power spectrum, the degradation in S/N by non-Gaussian errors is mitigated due to nonlinear redshift distortions. (5) For an actual galaxy survey, the additional shot...
The C IV Forest as a Probe of Baryon Acoustic Oscillations
Pieri, Matthew M
2014-01-01
In light of recent successes in measuring baryon acoustic oscillations in quasar absorption using the Lyman-alpha (Ly-alpha) transition, I explore the possibility of using the 1548 Ang transition of triply-ionized carbon (C IV) as a tracer. While the Ly-alpha forest is a more sensitive tracer of intergalactic gas, it is limited by the fact that it can only be measured in the optical window at redshifts z > 2. Quasars are challenging to identify and observe at these high-redshifts, but the C IV forest can be probed down to redshifts z = 1.3, taking full advantage of the peak in the redshift distribution of quasars that can be targeted with high efficiency. I explore the strength of the C IV absorption signal and show that the absorbing population on the red side of the Ly-alpha emission line is dominated by C IV. As a consequence, I argue that forthcoming surveys will have a sufficient increase in quasar number density to offset the lower sensitivity of the C IV forest and provide competitive precision using b...
Testing cosmic transparency with the latest baryon acoustic oscillations and type Ia supernovae data
Institute of Scientific and Technical Information of China (English)
Jun Chen; Pu-Xun Wu; Hong-Wei Yu; Zheng-Xiang Li
2013-01-01
Observations show that Type Ia supernovae (SNe Ia) are dimmer than expected from a matter dominated Universe.It has been suggested that this observed phenomenon can also be explained using light absorption instead of dark energy.However,there is a serious degeneracy between the cosmic absorption parameter and the present matter density parameter Ωm when one tries to place constraints on the cosmic opacity using SNe Ia data.We combine the latest baryon acoustic oscillation (BAO) and Union2 SNe Ia data in order to break this degeneracy.Assuming a flat ACDM model,we find that,although an opaque Universe is favored by SNe Ia+BAO since the best fit value of the cosmic absorption parameter is larger than zero,Ωm =1 is ruled out at the 99.7％ confidence level.Thus,cosmic opacity is not sufficient to account for the present observations and dark energy or modified gravity is still required.
The 6dF Galaxy Survey: Baryon Acoustic Oscillations and the Local Hubble Constant
Beutler, Florian; Colless, Matthew; Jones, D Heath; Staveley-Smith, Lister; Campbell, Lachlan; Parker, Quentin; Saunders, Will; Watson, Fred
2011-01-01
We analyse the large-scale correlation function of the 6dF Galaxy Survey (6dFGS) and detect a Baryon Acoustic Oscillation (BAO) signal. The 6dFGS BAO detection allows us to constrain the distance-redshift relation at z_{\\rm eff} = 0.106. We achieve a distance measure of D_V(z_{\\rm eff}) = 456\\pm27 Mpc and a measurement of the distance ratio, r_s(z_d)/D_V(z_{\\rm eff}) = 0.336\\pm0.015 (4.5% precision), where r_s(z_d) is the sound horizon at the drag epoch z_d. The low effective redshift of 6dFGS makes it a competitive and independent alternative to Cepheids and low-z supernovae in constraining the Hubble constant. We find a Hubble constant of H_0 = 67\\pm3.2 km s^{-1} Mpc^{-1} (4.8% precision) that depends only on the WMAP-7 calibration of the sound horizon and on the galaxy clustering in 6dFGS. Compared to earlier BAO studies at higher redshift, our analysis is less dependent on other cosmological parameters. The sensitivity to H_0 can be used to break the degeneracy between the dark energy equation of state pa...
Hunting down systematics in baryon acoustic oscillations after cosmic high noon
Prada, Francisco; Chuang, Chia-Hsun; Yepes, Gustavo; Klypin, Anatoly A; Kitaura, Francisco-Shu; Gottlober, Stefan
2014-01-01
Future dark energy experiments will require better and more accurate theoretical predictions for the baryonic acoustic oscillations (BAO) signature in the spectrum of cosmological perturbations. Here, we use large N-body simulations of the \\LambdaCDM Planck cosmology to study any possible systematic shifts and damping in BAO due to the impact of nonlinear gravitational growth of structure, scale dependent and non-local bias, and redshift-space distortions. The effect of cosmic variance is largely reduced by dividing the tracer power spectrum by that from a BAO-free simulation starting with the same phases. This permits us to study with unprecedented accuracy (better than 0.02% for dark matter and 0.07% for low-bias halos) small shifts of the pristine BAO wavenumbers towards larger k, and non-linear damping of BAO wiggles in the power spectrum of dark matter and halo populations in the redshift range z=0-1. For dark matter, we provide an accurate parametrization of the evolution of \\alpha as a function of the ...
Keselman, J. A.; Nusser, A.
2017-01-01
NoAM for "No Action Method" is a framework for reconstructing the past orbits of observed tracers of the large scale mass density field. It seeks exact solutions of the equations of motion (EoM), satisfying initial homogeneity and the final observed particle (tracer) positions. The solutions are found iteratively reaching a specified tolerance defined as the RMS of the distance between reconstructed and observed positions. Starting from a guess for the initial conditions, NoAM advances particles using standard N-body techniques for solving the EoM. Alternatively, the EoM can be replaced by any approximation such as Zel'dovich and second order perturbation theory (2LPT). NoAM is suitable for billions of particles and can easily handle non-regular volumes, redshift space, and other constraints. We implement NoAM to systematically compare Zel'dovich, 2LPT, and N-body dynamics over diverse configurations ranging from idealized high-res periodic simulation box to realistic galaxy mocks. Our findings are (i) Non-linear reconstructions with Zel'dovich, 2LPT, and full dynamics perform better than linear theory only for idealized catalogs in real space. For realistic catalogs, linear theory is the optimal choice for reconstructing velocity fields smoothed on scales {buildrel > over {˜}} 5 h^{-1}{Mpc}.(ii) all non-linear back-in-time reconstructions tested here, produce comparable enhancement of the baryonic oscillation signal in the correlation function.
Galaxy Bias and its Effects on the Baryon Acoustic Oscillations Measurements
Mehta, Kushal T; Eckel, Jonathan; Eisenstein, Daniel J; Metchnik, Marc; Pinto, Philip; Xu, Xiaoying
2011-01-01
The baryon acoustic oscillation (BAO) feature in the clustering of matter in the universe serves as a robust standard ruler and hence can be used to map the expansion history of the universe. We use high force resolution simulations to analyze the effects of galaxy bias on the measurements of the BAO signal. We apply a variety of Halo Occupation Distributions (HODs) and produce biased mass tracers to mimic different galaxy populations. We investigate whether galaxy bias changes the non-linear shifts on the acoustic scale relative to the underlying dark matter distribution presented by Seo et al (2009). For the less biased HOD models (b 3) show a shift at moderate significance (0.79% \\pm 0.31% for the most extreme case). We test the one-step reconstruction technique introduced by Eisenstein et al. (2007) in the case of realistic galaxy bias and shot noise. The reconstruction scheme increases the correlation between the initial and final (z = 1) density fields achieving an equivalent level of correlation at ne...
Measuring the 2D Baryon Acoustic Oscillation signal of galaxies in WiggleZ: Cosmological constraints
Hinton, Samuel R; Davis, Tamara M; Blake, Chris; Brough, Sarah; Colless, Matthew; Couch, Warrick J; Drinkwater, Michael J; Glazebrook, Karl; Jurek, Russel J; Parkinson, David; Pimbblet, Kevin A; Poole, Gregory B; Pracy, Michael; Woods, David
2016-01-01
We present results from the 2D anisotropic Baryon Acoustic Oscillation (BAO) signal present in the final dataset from the WiggleZ Dark Energy Survey. We analyse the WiggleZ data in two ways: firstly using the full shape of the 2D correlation function and secondly focussing only on the position of the BAO peak in the reconstructed data set. When fitting for the full shape of the 2D correlation function we use a multipole expansion to compare with theory. When we use the reconstructed data we marginalise over the shape and just measure the position of the BAO peak, analysing the data in wedges separating the signal along the line of sight from that parallel to the line of sight. We verify our method with mock data and find the results to be free of bias or systematic offsets. We also redo the pre-reconstruction angle averaged (1D) WiggleZ BAO analysis with an improved covariance and present an updated result. The final results are presented in the form of $\\Omega_c h^2$, $H(z)$, and $D_A(z)$ for three redshift ...
Valiviita, Jussi
2015-01-01
We employ the Planck 2013 CMB temperature anisotropy and lensing data, and baryon acoustic oscillation (BAO) data to constrain a phenomenological $w$CDM model, where dark matter and dark energy interact. We assume time-dependent equation of state parameter for dark energy, and treat dark matter and dark energy as fluids whose energy-exchange rate is proportional to the dark-matter density. The CMB data alone leave a strong degeneracy between the interaction rate and the physical CDM density parameter today, $\\omega_c$, allowing a large interaction rate $|\\Gamma| \\sim H_0$. However, as has been known for a while, the BAO data break this degeneracy. Moreover, we exploit the CMB lensing potential likelihood, which probes the matter perturbations at redshift $z \\sim 2$ and is very sensitive to the growth of structure, and hence one of the tools for discerning between the $\\Lambda$CDM model and its alternatives. However, we find that in the non-phantom models ($w_{\\mathrm{de}}>-1$), the constraints remain unchange...
An accurate determination of the Hubble constant from Baryon Acoustic Oscillation datasets
Cheng, Cheng
2014-01-01
Even though the Hubble constant cannot be significantly determined by the low-redshift Baryon Acoustic Oscillation (BAO) data alone, it can be tightly constrained once the high-redshift BAO data are combined. Combining BAO data from 6dFGS, BOSS DR11 clustering of galaxies, WiggleZ and $z=2.34$ from BOSS DR11 quasar Lyman-$\\alpha$ forest lines, we get $H_0=68.17^{+1.55}_{-1.56}$ km s$^{-1}$ Mpc$^{-1}$. In addition, adopting the the simultaneous measurements of $H(z)$ and $D_A(z)$ from the two-dimensional two-point correlation function from BOSS DR9 CMASS sample and two-dimensional matter power spectrum from SDSS DR7 sample, we obtain $H_0=68.11\\pm1.69$ km s$^{-1}$ Mpc$^{-1}$. Finally, combining all of the BAO datasets, we conclude $H_0=68.11\\pm 0.86$ km s$^{-1}$ Mpc$^{-1}$, a 1.3% determination.
Baryonic acoustic oscillations from 21cm intensity mapping: the Square Kilometre Array case
Villaescusa-Navarro, Francisco; Viel, Matteo
2016-01-01
We quantitatively investigate the possibility of detecting baryonic acoustic oscillations (BAO) using single-dish 21cm intensity mapping observations in the post-reionization era. We show that the telescope beam smears out the isotropic BAO signature and, in the case of the Square Kilometer Array (SKA) instrument, makes it undetectable at redshifts $z\\gtrsim1$. We however demonstrate that the BAO peak can still be detected in the radial 21cm power spectrum and describe a method to make this type of measurements. By means of numerical simulations, containing the 21cm cosmological signal as well as the most relevant Galactic and extra-Galactic foregrounds and basic instrumental effect, we quantify the precision with which the radial BAO scale can be measured in the 21cm power spectrum. We systematically investigate the signal-to-noise and the precision of the recovered BAO signal as a function of cosmic variance, instrumental noise, angular resolution and foreground contamination. We find that the expected nois...
Blake, Chris; Beutler, Florian; Davis, Tamara; Parkinson, David; Brough, Sarah; Colless, Matthew; Contreras, Carlos; Couch, Warrick; Croom, Scott; Croton, Darren; Drinkwater, Michael J; Forster, Karl; Gilbank, David; Gladders, Mike; Glazebrook, Karl; Jelliffe, Ben; Jurek, Russell J; Li, I-hui; Madore, Barry; Martin, Chris; Pimbblet, Kevin; Poole, Gregory; Pracy, Michael; Sharp, Rob; Wisnioski, Emily; Woods, David; Wyder, Ted; Yee, Howard
2011-01-01
We present measurements of the baryon acoustic peak at redshifts z = 0.44, 0.6 and 0.73 in the galaxy correlation function of the final dataset of the WiggleZ Dark Energy Survey. We combine our correlation function with lower-redshift measurements from the 6-degree Field Galaxy Survey and Sloan Digital Sky Survey, producing a stacked survey correlation function in which the statistical significance of the detection of the baryon acoustic peak is 4.9-sigma relative to a zero-baryon model with no peak. We fit cosmological models to this combined baryon acoustic oscillation (BAO) dataset comprising six distance-redshift data points, and compare the results to similar fits to the latest compilation of supernovae (SNe) and Cosmic Microwave Background (CMB) data. The BAO and SNe datasets produce consistent measurements of the equation-of-state w of dark energy, when separately combined with the CMB, providing a powerful check for systematic errors in either of these distance probes. Combining all datasets we determ...
Galaxy bias and its effects on the Baryon acoustic oscillations measurements
Energy Technology Data Exchange (ETDEWEB)
Mehta, Kushal T. [Univ. of Arizona, Tucson, AZ (United States); Seo, Hee -Jong [Univ. of California, Berkeley, CA (United States); Fermi National Accelerator Lab., Batavia, IL (United States); Eckel, Jonathan [Univ. of Arizona, Tucson, AZ (United States); Eisenstein, Daniel J. [Univ. of Arizona, Tucson, AZ (United States); Harvard Univ., Cambridge, MA (United States); Metchnik, Marc [Univ. of Arizona, Tucson, AZ (United States); Pinto, Philip [Univ. of Arizona, Tucson, AZ (United States); Xu, Xiaoying [Univ. of Arizona, Tucson, AZ (United States)
2011-05-31
The baryon acoustic oscillation (BAO) feature in the clustering of matter in the universe serves as a robust standard ruler and hence can be used to map the expansion history of the universe. We use high force resolution simulations to analyze the effects of galaxy bias on the measurements of the BAO signal. We apply a variety of Halo Occupation Distributions (HODs) and produce biased mass tracers to mimic different galaxy populations. We investigate whether galaxy bias changes the non-linear shifts on the acoustic scale relative to the underlying dark matter distribution presented by Seo et al. (2009). For the less biased HOD models (b < 3), we do not detect any shift in the acoustic scale relative to the no-bias case, typically 0.10% ± 0.10%. However, the most biased HOD models (b > 3) show a shift at moderate significance (0.79% ± 0.31% for the most extreme case). We test the one-step reconstruction technique introduced by Eisenstein et al. (2007) in the case of realistic galaxy bias and shot noise. The reconstruction scheme increases the correlation between the initial and final (z = 1) density fields achieving an equivalent level of correlation at nearly twice the wavenumber after reconstruction. Reconstruction reduces the shifts and errors on the shifts. We find that after reconstruction the shifts from the galaxy cases and the dark matter case are consistent with each other and with no shift. The 1σ systematic errors on the distance measurements inferred from our BAO measurements with various HODs after reconstruction are about 0.07%-0.15%.
MODEL-INDEPENDENT EVIDENCE FOR DARK ENERGY EVOLUTION FROM BARYON ACOUSTIC OSCILLATIONS
Energy Technology Data Exchange (ETDEWEB)
Sahni, V. [Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India); Shafieloo, A. [Asia Pacific Center for Theoretical Physics, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Starobinsky, A. A., E-mail: varun@iucaa.ernet.in, E-mail: arman@apctp.org, E-mail: alstar@landau.ac.ru [Landau Institute for Theoretical Physics RAS, Moscow 119334 (Russian Federation)
2014-10-01
Baryon acoustic oscillations (BAOs) allow us to determine the expansion history of the universe, thereby shedding light on the nature of dark energy. Recent observations of BAOs in the Sloan Digital Sky Survey (SDSS) DR9 and DR11 have provided us with statistically independent measurements of H(z) at redshifts of 0.57 and 2.34, respectively. We show that these measurements can be used to test the cosmological constant hypothesis in a model-independent manner by means of an improved version of the Om diagnostic. Our results indicate that the SDSS DR11 measurement of H(z) = 222 ± 7 km s{sup –1} Mpc{sup –1} at z = 2.34, when taken in tandem with measurements of H(z) at lower redshifts, imply considerable tension with the standard ΛCDM model. Our estimation of the new diagnostic Omh {sup 2} from SDSS DR9 and DR11 data, namely, Omh {sup 2} ≈ 0.122 ± 0.01, which is equivalent to Ω{sub 0m} h {sup 2} for the spatially flat ΛCDM model, is in tension with the value Ω{sub 0m} h {sup 2} = 0.1426 ± 0.0025 determined for ΛCDM from Planck+WP. This tension is alleviated in models in which the cosmological constant was dynamically screened (compensated) in the past. Such evolving dark energy models display a pole in the effective equation of state of dark energy at high redshifts, which emerges as a smoking gun test for these theories.
Baryonic acoustic oscillations from 21 cm intensity mapping: the Square Kilometre Array case
Villaescusa-Navarro, Francisco; Alonso, David; Viel, Matteo
2017-04-01
We quantitatively investigate the possibility of detecting baryonic acoustic oscillations (BAO) using single-dish 21 cm intensity mapping observations in the post-reionization era. We show that the telescope beam smears out the isotropic BAO signature and, in the case of the Square Kilometre Array (SKA) instrument, makes it undetectable at redshifts z ≳ 1. We however demonstrate that the BAO peak can still be detected in the radial 21 cm power spectrum and describe a method to make this type of measurements. By means of numerical simulations, containing the 21 cm cosmological signal as well as the most relevant Galactic and extra-Galactic foregrounds and basic instrumental effect, we quantify the precision with which the radial BAO scale can be measured in the 21 cm power spectrum. We systematically investigate the signal to noise and the precision of the recovered BAO signal as a function of cosmic variance, instrumental noise, angular resolution and foreground contamination. We find that the expected noise levels of SKA would degrade the final BAO errors by ∼5 per cent with respect to the cosmic-variance limited case at low redshifts, but that the effect grows up to ∼65 per cent at z ∼ 2-3. Furthermore, we find that the radial BAO signature is robust against foreground systematics, and that the main effect is an increase of ∼20 per cent in the final uncertainty on the standard ruler caused by the contribution of foreground residuals as well as the reduction in sky area needed to avoid high-foreground regions. We also find that it should be possible to detect the radial BAO signature with high significance in the full redshift range. We conclude that a 21 cm experiment carried out by the SKA should be able to make direct measurements of the expansion rate H(z) with measure the expansion with competitive per cent level precision on redshifts z ≲ 2.5.
Nishimichi, Takahiro; Nakamichi, Masashi; Taruya, Atsushi; Yahata, Kazuhiro; Shirata, Akihito; Saito, Shun; Nomura, Hidenori; Yamamoto, Kazuhiro; Suto, Yasushi
2007-01-01
An acoustic oscillation of the primeval photon-baryon fluid around the decoupling time imprints a characteristic scale in the galaxy distribution today, known as the baryon acoustic oscillation (BAO) scale. Several on-going and/or future galaxy surveys aim at detecting and precisely determining the BAO scale so as to trace the expansion history of the universe. We consider nonlinear and redshift-space distortion effects on the shifts of the BAO scale in $k$-space using perturbation theory. The resulting shifts are indeed sensitive to different choices of the definition of the BAO scale, which needs to be kept in mind in the data analysis. We present a toy model to explain the physical behavior of the shifts. We find that the BAO scale defined as in Percival et al. (2007) indeed shows very small shifts ($\\lesssim$ 1%) relative to the prediction in {\\it linear theory} in real space. The shifts can be predicted accurately for scales where the perturbation theory is reliable.
Hoeneisen, B
2016-01-01
We define Baryon Acoustic Oscillation (BAO) distances $\\hat{d}_\\alpha(z, z_c)$, $\\hat{d}_z(z, z_c)$, and $\\hat{d}_/(z, z_c)$ that do not depend on cosmological parameters. These BAO distances are measured as a function of redshift $z$ with the Sloan Digital Sky Survey (SDSS) data release DR12. From these BAO distances alone, or together with the correlation angle $\\theta_\\textrm{MC}$ of the Cosmic Microwave Background (CMB), we constrain the cosmological parameters in several scenarios. We find $4.3 \\sigma$ tension between the BAO plus $\\theta_\\textrm{MC}$ data and a cosmology with flat space and constant dark energy density $\\Omega_\\textrm{DE}(a)$. Releasing one and/or the other of these constraints obtains agreement with the data. We measure $\\Omega_\\textrm{DE}(a)$ as a function of $a$.
Moldenhauer, Jacob; Thompson, John; Easson, Damien A
2010-01-01
We consider recently proposed higher order gravity models where the action is built from the Einstein-Hilbert action plus a function f(G) of the Gauss-Bonnet invariant. The models were previously shown to pass physical acceptability conditions as well as solar system tests. In this paper, we compare the models to combined data sets of supernovae, baryon acoustic oscillations, and constraints from the CMB surface of last scattering. We find that the models provide fits to the data that are close to those of the LCDM concordance model. The results provide a pool of higher order gravity models that pass these tests and need to be compared to constraints from large scale structure and full CMB analysis.
Energy Technology Data Exchange (ETDEWEB)
Kirkby, David; Margala, Daniel; Blomqvist, Michael [Department of Physics and Astronomy, University of California, Irvine, 92697 (United States); Slosar, Anže [Brookhaven National Laboratory, Blgd 510, Upton NY 11375 (United States); Bailey, Stephen; Carithers, Bill [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Busca, Nicolás G.; Bautista, Julian E. [APC, Université Paris Diderot-Paris 7, CNRS/IN2P3, CEA, Observatoire de Paris, 10, rue A. Domon and L. Duquet, Paris (France); Delubac, Timothée; Rich, James; Palanque-Delabrouille, Nathalie [CEA, Centre de Saclay, IRFU, F-91191 Gif-sur-Yvette (France); Brownstein, Joel R.; Dawson, Kyle S. [Department of Physics and Astronomy, University of Utah, 115 S 1400 E, Salt Lake City, UT 84112 (United States); Croft, Rupert A.C. [Bruce and Astrid McWilliams Center for Cosmology, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Font-Ribera, Andreu [Institute of Theoretical Physics, University of Zurich, 8057 Zurich (Switzerland); Miralda-Escudé, Jordi [Institució Catalana de Recerca i Estudis Avançats, Barcelona, Catalonia (Spain); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Nichol, Robert C. [Institute of Cosmology and Gravitation, Dennis Sciama Building, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Pâris, Isabelle; Petitjean, Patrick, E-mail: dkirkby@uci.edu [Université Paris 6 et CNRS, Institut d' Astrophysique de Paris, 98bis blvd. Arago, 75014 Paris (France); and others
2013-03-01
We describe fitting methods developed to analyze fluctuations in the Lyman-α forest and measure the parameters of baryon acoustic oscillations (BAO). We apply our methods to BOSS Data Release 9. Our method is based on models of the three-dimensional correlation function in physical coordinate space, and includes the effects of redshift-space distortions, anisotropic non-linear broadening, and broadband distortions. We allow for independent scale factors along and perpendicular to the line of sight to minimize the dependence on our assumed fiducial cosmology and to obtain separate measurements of the BAO angular and relative velocity scales. Our fitting software and the input files needed to reproduce our main BOSS Data Release 9 results are publicly available.
Kitaura, Francisco-Shu; Chuang, Chia-Hsun; Liang, Yu; Zhao, Cheng; Tao, Charling; Rodríguez-Torres, Sergio; Eisenstein, Daniel J.; Gil-Marín, Héctor; Kneib, Jean-Paul; McBride, Cameron; Percival, Will J.; Ross, Ashley J.; Sánchez, Ariel G.; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magana, Mariana; Zhao, Gong-Bo
2016-04-01
Sound waves from the primordial fluctuations of the Universe imprinted in the large-scale structure, called baryon acoustic oscillations (BAOs), can be used as standard rulers to measure the scale of the Universe. These oscillations have already been detected in the distribution of galaxies. Here we propose to measure BAOs from the troughs (minima) of the density field. Based on two sets of accurate mock halo catalogues with and without BAOs in the seed initial conditions, we demonstrate that the BAO signal cannot be obtained from the clustering of classical disjoint voids, but it is clearly detected from overlapping voids. The latter represent an estimate of all troughs of the density field. We compute them from the empty circumsphere centers constrained by tetrahedra of galaxies using Delaunay triangulation. Our theoretical models based on an unprecedented large set of detailed simulated void catalogues are remarkably well confirmed by observational data. We use the largest recently publicly available sample of luminous red galaxies from SDSS-III BOSS DR11 to unveil for the first time a >3 σ BAO detection from voids in observations. Since voids are nearly isotropically expanding regions, their centers represent the most quiet places in the Universe, keeping in mind the cosmos origin and providing a new promising window in the analysis of the cosmological large-scale structure from galaxy surveys.
Kitaura, Francisco-Shu; Chuang, Chia-Hsun; Liang, Yu; Zhao, Cheng; Tao, Charling; Rodríguez-Torres, Sergio; Eisenstein, Daniel J; Gil-Marín, Héctor; Kneib, Jean-Paul; McBride, Cameron; Percival, Will J; Ross, Ashley J; Sánchez, Ariel G; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magana, Mariana; Zhao, Gong-Bo
2016-04-29
Sound waves from the primordial fluctuations of the Universe imprinted in the large-scale structure, called baryon acoustic oscillations (BAOs), can be used as standard rulers to measure the scale of the Universe. These oscillations have already been detected in the distribution of galaxies. Here we propose to measure BAOs from the troughs (minima) of the density field. Based on two sets of accurate mock halo catalogues with and without BAOs in the seed initial conditions, we demonstrate that the BAO signal cannot be obtained from the clustering of classical disjoint voids, but it is clearly detected from overlapping voids. The latter represent an estimate of all troughs of the density field. We compute them from the empty circumsphere centers constrained by tetrahedra of galaxies using Delaunay triangulation. Our theoretical models based on an unprecedented large set of detailed simulated void catalogues are remarkably well confirmed by observational data. We use the largest recently publicly available sample of luminous red galaxies from SDSS-III BOSS DR11 to unveil for the first time a >3σ BAO detection from voids in observations. Since voids are nearly isotropically expanding regions, their centers represent the most quiet places in the Universe, keeping in mind the cosmos origin and providing a new promising window in the analysis of the cosmological large-scale structure from galaxy surveys.
Hernandez-Monteagudo, Carlos; Cuesta, Antonio; Genova-Santos, Ricardo; Prada, Francisco; Rossi, Graziano; Neyrinck, Mark; Viel, Matteo; Rubino-Martin, Jose-Alberto; Scoccola, Claudia G; Zhao, Gongbo; Schneider, Donald P; Brownstein, Joel R; Thomas, Daniel; Brinkmann, Jonathan V
2013-01-01
In the context of the study of the Integrated Sachs Wolfe effect (ISW), we construct a template of the projected density distribution up to $z\\simeq 0.7$ by using the Luminous Galaxies (LGs) from the Sloan Digital Sky Survey DR8. We use a photo-z catalogue trained with more than a hundred thousand galaxies from BOSS in the SDSS DR8 imaging area. We consider two different LG samples whose selection matches that of SDSS-III/BOSS: the LOWZ sample ($z\\in [0.15,0.5]$) and the CMASS sample ($z\\in[0.4,0.7]$). When building the LG density maps we use the information from star density, survey footprint, seeing conditions, sky emission, dust extinction and airmass to explore the impact of these artifacts on the two LG samples. In agreement with previous studies, we find that the CMASS sample is particularly sensitive to Galactic stars, which dominate the contribution to the auto-angular power spectrum below $\\ell=7$. Other potential systematics affect mostly the low multipole range ($\\ell\\in[2,7]$), but leave fluctuati...
New constraints on H_0 and Omega_M from SZE/X-RAY data and Baryon Acoustic Oscillations
Holanda, R F L; Lima, J A S
2008-01-01
The Hubble constant, $H_0$, sets the scale of the size and age of the Universe and its determination from independent methods is still worthwhile to be investigated. In this article, by using the Sunyaev-Zel`dovich effect and X-ray surface brightness data from 38 galaxy clusters observed by Bonamente {\\it{et al.}} (2006), we obtain a new estimate of $H_0$ in the context of a flat $\\Lambda$CDM model. There is a degeneracy on the mass density parameter ($\\Omega_{m}$) which is broken by applying a joint analysis involving the baryon acoustic oscillations (BAO) as given by Sloan Digital Sky Survey (SDSS). This happens because the BAO signature does not depend on $H_0$. Our basic finding is that a joint analysis involving these tests yield $H_0= 0.765^{+0.035}_{-0.033}$ km s$^{-1}$ Mpc$^{-1}$ and $\\Omega_{m}=0.27^{+0.03}_{-0.02}$. Since the hypothesis of spherical geometry assumed by Bonamente {\\it {et al.}} is questionable, we have also compared the above results to a recent work where a sample of triaxial galaxy...
Directory of Open Access Journals (Sweden)
S. N. Gninenko
2012-01-01
Full Text Available Standard Model fails to explain neutrino oscillations, dark matter, and baryon asymmetry of the Universe. All these problems can be solved with three sterile neutrinos added to SM. Quite remarkably, if sterile neutrino masses are well below the electroweak scale, this modification—Neutrino Minimal Standard Model (νMSM—can be tested experimentally. We discuss a new experiment on search for decays of GeV-scale sterile neutrinos, which are responsible for the matter-antimatter asymmetry generation and for the active neutrino masses. If lighter than 2 GeV, these particles can be produced in decays of charm mesons generated by high energy protons in a target, and subsequently decay into SM particles. To fully explore this sector of νMSM, the new experiment requires data obtained with at least 1020 incident protons on target (achievable at CERN SPS in future and a big volume detector constructed from a large amount of identical single modules, with a total sterile neutrino decay length of few kilometers. The preliminary feasibility study for the proposed experiment shows that it has sensitivity which may either lead to the discovery of new particles below the Fermi scale—right-handed partners of neutrinos—or rule out seesaw sterile neutrinos with masses below 2 GeV.
Diode pumped solid-state laser oscillators for spectroscopic applications
Byer, R. L.; Basu, S.; Fan, T. Y.; Kozlovsky, W. J.; Nabors, C. D.; Nilsson, A.; Huber, G.
1987-01-01
The rapid improvement in diode laser pump sources has led to the recent progress in diode laser pumped solid state lasers. To date, electrical efficiencies of greater than 10 percent were demonstrated. As diode laser costs decrease with increased production volume, diode laser and diode laser array pumped solid state lasers will replace the traditional flashlamp pumped Nd:YAG laser sources. The use of laser diode array pumping of slab geometry lasers will allow efficient, high peak and average power solid state laser sources to be developed. Perhaps the greatest impact of diode laser pumped solid state lasers will be in spectroscopic applications of miniature, monolithic devices. Single-stripe diode-pumped operation of a continuous-wave 946 nm Nd:YAG laser with less than 10 m/w threshold was demonstrated. A slope efficiency of 16 percent near threshold was shown with a projected slope efficiency well above a threshold of 34 percent based on results under Rhodamine 6G dye-laser pumping. Nonlinear crystals for second-harmonic generation of this source were evaluated. The KNbO3 and periodically poled LiNbO3 appear to be the most promising.
Babu, K S; Al-Binni, U; Banerjee, S; Baxter, D V; Berezhiani, Z; Bergevin, M; Bhattacharya, S; Brice, S; Brock, R; Burgess, T W; Castellanos, L; Chattopadhyay, S; Chen, M-C; Church, E; Coppola, C E; Cowen, D F; Cowsik, R; Crabtree, J A; Davoudiasl, H; Dermisek, R; Dolgov, A; Dutta, B; Dvali, G; Ferguson, P; Perez, P Fileviez; Gabriel, T; Gal, A; Gallmeier, F; Ganezer, K S; Gogoladze, I; Golubeva, E S; Graves, V B; Greene, G; Handler, T; Hartfiel, B; Hawari, A; Heilbronn, L; Hill, J; Jaffe, D; Johnson, C; Jung, C K; Kamyshkov, Y; Kerbikov, B; Kopeliovich, B Z; Kopeliovich, V B; Korsch, W; Lachenmaier, T; Langacker, P; Liu, C-Y; Marciano, W J; Mocko, M; Mohapatra, R N; Mokhov, N; Muhrer, G; Mumm, P; Nath, P; Obayashi, Y; Okun, L; Pati, J C; Pattie, R W; Phillips, D G; Quigg, C; Raaf, J L; Raby, S; Ramberg, E; Ray, A; Roy, A; Ruggles, A; Sarkar, U; Saunders, A; Serebrov, A; Shafi, Q; Shimizu, H; Shiozawa, M; Shrock, R; Sikdar, A K; Snow, W M; Soha, A; Spanier, S; Stavenga, G C; Striganov, S; Svoboda, R; Tang, Z; Tavartkiladze, Z; Townsend, L; Tulin, S; Vainshtein, A; Van Kooten, R; Wagner, C E M; Wang, Z; Wehring, B; Wilson, R J; Wise, M; Yokoyama, M; Young, A R
2013-01-01
This report, prepared for the Community Planning Study - Snowmass 2013 - summarizes the theoretical motivations and the experimental efforts to search for baryon number violation, focussing on nucleon decay and neutron-antineutron oscillations. Present and future nucleon decay search experiments using large underground detectors, as well as planned neutron-antineutron oscillation search experiments with free neutron beams are highlighted.
Energy Technology Data Exchange (ETDEWEB)
Frederick, B.deB. [California Univ., Berkeley, CA (United States)]|[Lawrence Berkeley Lab., CA (United States)
1994-12-01
Nuclear magnetic resonance (NMR) spectroscopic imaging of {sup 23}Na holds promise as a non-invasive method of mapping Na{sup +} distributions, and for differentiating pools of Na{sup +} ions in biological tissues. However, due to NMR relaxation properties of {sup 23}Na in vivo, a large fraction of Na{sup +} is not visible with conventional NMR imaging methods. An alternate imaging method, based on stochastic excitation and oscillating gradients, has been developed which is well adapted to measuring nuclei with short T{sub 2}. Contemporary NMR imaging techniques have dead times of up to several hundred microseconds between excitation and sampling, comparable to the shortest in vivo {sup 23}Na T{sub 2} values, causing significant signal loss. An imaging strategy based on stochastic excitation has been developed which greatly reduces experiment dead time by reducing peak radiofrequency (RF) excitation power and using a novel RF circuit to speed probe recovery. Continuously oscillating gradients are used to eliminate transient eddy currents. Stochastic {sup 1}H and {sup 23}Na spectroscopic imaging experiments have been performed on a small animal system with dead times as low as 25{mu}s, permitting spectroscopic imaging with 100% visibility in vivo. As an additional benefit, the encoding time for a 32x32x32 spectroscopic image is under 30 seconds. The development and analysis of stochastic NMR imaging has been hampered by limitations of the existing phase demodulation reconstruction technique. Three dimensional imaging was impractical due to reconstruction time, and design and analysis of proposed experiments was limited by the mathematical intractability of the reconstruction method. A new reconstruction method for stochastic NMR based on Fourier interpolation has been formulated combining the advantage of a several hundredfold reduction in reconstruction time with a straightforward mathematical form.
Samanta, T; Sindhuja, G; Banerjee, D
2015-01-01
During the total solar eclipse of 11 July 2010, multi-slit spectroscopic observations of the solar corona were performed from Easter Island, Chile. To search for high-frequency waves, observations were taken at a high cadence in the green line at 5303 A due to [Fe xiv] and the red line at 6374 A due to [Fe x]. The data are analyzed to study the periodic variations in the intensity, Doppler velocity and line width using wavelet analysis. The data with high spectral and temporal resolution enabled us to study the rapid dynamical changes within coronal structures. We find that at certain locations each parameter shows significant oscillation with periods ranging from 6 - 25 s. For the first time, we could detect damping of high-frequency oscillations with periods of the order of 10 s. If the observed damped oscillations are due to magnetohydrodynamic (MHD) waves then they can contribute significantly in the heating of the corona. From a statistical study we try to characterize the nature of the observed oscillat...
Page, P R
2003-01-01
We review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modelled by both the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.
Oset, E; Sun, Bao Xi; Vacas, M J Vicente; Ramos, A; Gonzalez, P; Vijande, J; Torres, A Martinez; Khemchandani, K
2009-01-01
In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the $\\Lambda(1405)$ resonance, as well as the prediction of one $1/2^+$ baryon state around 1920 MeV which might have been seen in the $\\gamma p \\to K^+ \\Lambda$ reaction.
Energy Technology Data Exchange (ETDEWEB)
Oset, E. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Sarkar, S. [Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064 (India); Sun Baoxi [Institute of Theoretical Physics, College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China); Vicente Vacas, M.J. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Ramos, A. [Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, 08028 Barcelona (Spain); Gonzalez, P. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Vijande, J. [Departamento de Fisica Atomica Molecular y Nuclear and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Martinez Torres, A. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Khemchandani, K. [Centro de Fisica Computacional, Departamento de Fisica, Universidade de Coimbra, P-3004-516 Coimbra (Portugal)
2010-04-01
In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the {lambda}(1405) resonance, as well as the prediction of one 1/2{sup +} baryon state around 1920 MeV which might have been seen in the {gamma}p{yields}K{sup +}{lambda} reaction.
Slepian, Zachary; Brownstein, Joel R; Chuang, Chia-Hsun; Gil-Marín, Héctor; Ho, Shirley; Kitaura, Francisco-Shu; Percival, Will J; Ross, Ashley J; Rossi, Graziano; Seo, Hee-Jong; Slosar, Anže; Vargas-Magaña, Mariana
2016-01-01
We present the large-scale 3-point correlation function (3PCF) of the SDSS DR12 CMASS sample of $777,202$ Luminous Red Galaxies, the largest-ever sample used for a 3PCF or bispectrum measurement. We make the first high-significance ($4.5\\sigma$) detection of Baryon Acoustic Oscillations (BAO) in the 3PCF. Using these acoustic features in the 3PCF as a standard ruler, we measure the distance to $z=0.57$ to $1.7\\%$ precision (statistical plus systematic). We find $D_{\\rm V}= 2024\\pm29\\;{\\rm Mpc\\;(stat)}\\pm20\\;{\\rm Mpc\\;(sys)}$ for our fiducial cosmology (consistent with Planck 2015) and bias model. This measurement extends the use of the BAO technique from the 2-point correlation function (2PCF) and power spectrum to the 3PCF and opens an avenue for deriving additional cosmological distance information from future large-scale structure redshift surveys such as DESI. Our measured distance scale from the 3PCF is fairly independent from that derived from the pre-reconstruction 2PCF and is equivalent to increasing ...
Hoeneisen, B
2016-01-01
We define Baryon Acoustic Oscillation (BAO) observables $\\hat{d}_\\alpha(z, z_c)$, $\\hat{d}_z(z, z_c)$, and $\\hat{d}_/(z, z_c)$ that do not depend on any cosmological parameter. From each of these observables we recover the BAO correlation length $d_\\textrm{BAO}$ with its respective dependence on cosmological parameters. These BAO observables are measured as a function of redshift $z$ with the Sloan Digital Sky Survey (SDSS) data release DR12. From the BAO measurements alone, or together with the correlation angle $\\theta_\\textrm{MC}$ of the Cosmic Microwave Background (CMB), we constrain the curvature parameter $\\Omega_k$ and the dark energy density $\\Omega_\\textrm{DE}(a)$ as a function of the expansion parameter $a$ in several scenarios. These observables are further constrained with external measurements of $h$ and $\\Omega_\\textrm{b} h^2$. We find some tension between the data and a cosmology with flat space and constant dark energy density $\\Omega_\\textrm{DE}(a)$.
Xu, Lixin
2013-01-01
In this paper, we use the joint measurement of geometry and growth rate from matter density perturbations to constrain the holographic dark energy model. The geometry measurement includes type Ia supernovae (SN Ia) Union2.1, full information of cosmic microwave background (CMB) from WMAP-7yr and baryon acoustic oscillation (BAO). For the growth rate of matter density perturbations, the results $f(z)\\sigma_8(z)$ measured from the redshift-space distortion (RSD) in the galaxy power spectrum are employed. Via the Markov Chain Monte Carlo method, we try to constrain the model parameters space. The jointed constraint shows that $c=0.750_{- 0.0999- 0.173- 0.226}^{+ 0.0976+ 0.215+ 0.319}$ and $\\sigma_8=0.763_{- 0.0465- 0.0826- 0.108}^{+ 0.0477+ 0.0910+ 0.120}$ with $1,2,3\\sigma$ regions. After marginalizing the other irrelevant model parameters, we show the evolution of the equation of state of HDE with respect to the redshift $z$. Though the current cosmic data points favor a phantom like HDE Universe for the mean ...
Soumagnac, M T; Sabiu, C G; Loeb, A; Ross, A J; Abdalla, F B; Balan, S T; Lahav, O
2016-01-01
Baryon Acoustic Oscillations (BAOs) in the early Universe are predicted to leave an as yet undetected signature on the relative clustering of total mass versus luminous matter. A detection of this effect would provide an important confirmation of the standard cosmological paradigm and constrain alternatives to dark matter as well as non-standard fluctuations such as Compensated Isocurvature Perturbations (CIPs). We conduct the first observational search for this effect, by comparing the number-weighted and luminosity-weighted correlation functions, using the SDSS-III BOSS Data Release 10 CMASS sample. When including CIPs in our model, we formally obtain evidence at $3.2\\sigma$ of the relative clustering signature and a limit that matches the existing upper limits on the amplitude of CIPs. However, various tests suggest that these results are not yet robust, perhaps due to systematic biases in the data. The method developed in this Letter, used with more accurate future data such as that from DESI, is likely t...
Energy Technology Data Exchange (ETDEWEB)
Farooq, Omer, E-mail: omer@phys.ksu.edu; Ratra, Bharat, E-mail: ratra@phys.ksu.edu
2013-06-10
We use the Busca et al. (2012) [11] measurement of the Hubble parameter at redshift z=2.3 in conjunction with 21 lower z measurements, from Simon, Verde, and Jimenez (2005) [81], Gaztañaga, Cabré, and Hui (2009) [33], Stern et al. (2010) [85], and Moresco et al. (2012) [52], to place constraints on model parameters of constant and time-evolving dark energy cosmological models. The inclusion of the new Busca et al. (2012) [11] measurement results in H(z) constraints significantly more restrictive than those derived by Farooq, Mania, and Ratra (2013) [31]. These H(z) constraints are now more restrictive than those that follow from current Type Ia supernova (SNIa) apparent magnitude measurements Suzuki et al. (2012) [86]. The H(z) constraints by themselves require an accelerating cosmological expansion at about 2 σ confidence level, depending on cosmological model and Hubble constant prior used in the analysis. A joint analysis of H(z), baryon acoustic oscillation peak length scale, and SNIa data favors a spatially-flat cosmological model currently dominated by a time-independent cosmological constant but does not exclude slowly-evolving dark energy density.
Beck, P G; Hillen, M; Corsaro, E; Van Winckel, H; Moravveji, E; De Ridder, J; Bloemen, S; Saesen, S; Mathias, P; Degroote, P; Kallinger, T; Verhoelst, T; Ando, H; Carrier, F; Acke, B; Oreiro, R; Miglio, A; Eggenberger, P; Sato, B; Zwintz, K; Pápics, P I; Marcos-Arenal, P; Fuentes, S A Sans; Schmid, V S; Waelkens, C; Østensen, R; Matthews, J M; Yoshida, M; Izumiura, H; Koyano, H; Nagayama, S; Shimizu, Y; Okada, N; Okita, K; Sakamoto, A; Yamamuro, T; Aerts, C
2014-01-01
Red giants are evolved stars which exhibit solar-like oscillations. Although a multitude of stars have been observed with space telescopes, only a handful of red-giant stars were targets of spectroscopic asteroseismic observing projects. We search for solar-like oscillations in the two bright red-giant stars $\\gamma$ Psc and $\\theta^1$ Tau from time series of ground-based spectroscopy and determine the frequency of the excess of oscillation power $\
Energy Technology Data Exchange (ETDEWEB)
Mukhopadhyay, N.C.
1986-01-01
The status of the theory of the low-energy approach to hadron structure is reviewed briefly by surveying a few relevant models. A few examples of tests needed to sort out the predictions of different models pertaining to the quark-gluon structure of hadrons are discussed, and given the resulting physics objectives, a few experimental options for excited baryon research at CFBAF are suggested. (LEW)
Gudnason, Sven Bjarke
2014-01-01
We study a Skyrme-type model with a potential term motivated by Bose-Einstein condensates (BECs), which we call the BEC Skyrme model. We consider two flavors of the model, the first is the Skyrme model and the second has a sixth-order derivative term instead of the Skyrme term; both with the added BEC-motivated potential. The model contains toroidally shaped Skyrmions and they are characterized by two integers P and Q, representing the winding numbers of two complex scalar fields along the toroidal and poloidal cycles of the torus, respectively. The baryon number is B=PQ. We find stable Skyrmion solutions for P=1,2,3,4,5 with Q=1, while for P=6 and Q=1 it is only metastable. We further find that configurations with higher Q>1 are all unstable and split into Q configurations with Q=1.
Energy Technology Data Exchange (ETDEWEB)
Wang, Yimeng; Zhang, Xinping, E-mail: Zhangxinping@bjut.edu.cn; Zhang, Jian; Liu, Hongmei [Institute of Information Photonics Technology and College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China)
2014-07-07
We investigate stretching-induced microscopic deformations spatially distributed in a flexible plate of polydimethylsiloxane (PDMS) and their applications in the broadening of the output spectrum of a femtosecond optical parametric oscillator. The hologram of the stretched PDMS plate was used to evaluate indirectly the microscopic deformations. The experimental results show that these deformations exhibit weak scattering and diffraction of light and induce negligible cavity loss, ensuring practical applications of the PDMS plate as an intracavity device for lasers. In combination with the thickness reduction of the PDMS plate through stretching, the distributed deformations enable smooth tuning of the output spectrum.
Arpin, Paul C; Turner, Daniel B; McClure, Scott D; Jumper, Chanelle C; Mirkovic, Tihana; Challa, J Reddy; Lee, Joohyun; Teng, Chang Ying; Green, Beverley R; Wilk, Krystyna E; Curmi, Paul M G; Hoef-Emden, Kerstin; McCamant, David W; Scholes, Gregory D
2015-08-06
The first step of photosynthesis is the absorption of light by antenna complexes. Recent studies of light-harvesting complexes using two-dimensional electronic spectroscopy have revealed interesting coherent oscillations. Some contributions to those coherences are assigned to electronic coherence and therefore have implications for theories of energy transfer. To assign these femtosecond data and to gain insight into the interplay among electronic and vibrational resonances, we need detailed information on vibrations and coherences in the excited electronic state compared to the ground electronic state. Here, we used broad-band transient absorption and femtosecond stimulated Raman spectroscopies to record ground- and excited-state coherences in four related photosynthetic proteins: PC577 from Hemiselmis pacifica CCMP706, PC612 from Hemiselmis virescens CCAC 1635 B, PC630 from Chroomonas CCAC 1627 B (marine), and PC645 from Chroomonas mesostigmatica CCMP269. Two of those proteins (PC630 and PC645) have strong electronic coupling while the other two proteins (PC577 and PC612) have weak electronic coupling between the chromophores. We report vibrational spectra for the ground and excited electronic states of these complexes as well as an analysis of coherent oscillations observed in the broad-band transient absorption data.
Fukushima, Kenji
2014-01-01
We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.
Chuang, Chia-Hsun; Rodríguez-Torres, Sergio; Ross, Ashley J; Zhao, Gong-bo; Wang, Yuting; Cuesta, Antonio J; Rubiño-Martín, J A; Prada, Francisco; Alam, Shadab; Beutler, Florian; Eisenstein, Daniel J; Gil-Marín, Héctor; Grieb, Jan Niklas; Ho, Shirley; Kitaura, Francisco-Shu; Percival, Will J; Rossi, Graziano; Salazar-Albornoz, Salvador; Samushia, Lado; Sánchez, Ariel G; Satpathy, Siddharth; Slosar, Anže; Tinker, Jeremy L; Tojeiro, Rita; Vargas-Magaña, Mariana; Vazquez, Jose A; Brownstein, Joel R; Nichol, Robert C; Olmstead, Matthew D
2016-01-01
We analyse the broad-range shape of the monopole and quadrupole correlation functions of the BOSS Data Release 12 (DR12) CMASS and LOWZ galaxy sample to obtain constraints on the Hubble expansion rate $H(z)$, the angular-diameter distance $D_A(z)$, the normalised growth rate $f(z)\\sigma_8(z)$, and the physical matter density $\\Omega_mh^2$. We adopt wide and flat priors on all model parameters in order to ensure the results are those of a `single-probe' galaxy clustering analysis. We also marginalise over three nuisance terms that account for potential observational systematics affecting the measured monopole. However, such Monte Carlo Markov Chain analysis is computationally expensive for advanced theoretical models, thus we develop a new methodology to speed up our analysis. We obtain $\\{D_A(z)r_{s,fid}/r_s$Mpc, $H(z)r_s/r_{s,fid}$kms$^{-1}$Mpc$^{-1}$, $f(z)\\sigma_8(z)$, $\\Omega_m h^2\\}$ = $\\{956\\pm28$ , $75.0\\pm4.0$ , $0.397 \\pm 0.073$, $0.143\\pm0.017\\}$ at $z=0.32$ and $\\{1421\\pm23$, $96.7\\pm2.7$ , $0.497 ...
Vargas-Magaña, Mariana; Ho, Shirley; Fromenteau, Sebastien.; Cuesta, Antonio. J.
2017-01-01
The reconstruction algorithm introduced by Eisenstein et al. (2007), which is widely used in clustering analysis, is based on the inference of the first order Lagrangian displacement field from the Gaussian smoothed galaxy density field in redshift space. The 2smoothing scale applied to the density field affects the inferred displacement field that is used to move the galaxies, and partially 2erases the nonlinear evolution of the density field. In this article, we explore this crucial step 2in the reconstruction algorithm. We study the performance of the reconstruction technique using two metrics: first, we study the performance using the anisotropic clustering, extending previous studies focused on isotropic clustering; second, we study its effect on the displacement field. We find that smoothing has a strong effect in the quadrupole of the correlation function and affects the accuracy and precision 2with which we can measure DA(z) and H(z). We find that the optimal smoothing scale to use in the reconstruction algorithm applied to BOSS-CMASS is between 5-10 h-1Mpc. Varying from the "usual" 15h-1Mpc to 5h-1Mpc 2shows ˜ 0.3% variations in DA(z) and ˜ 0.4% H(z) and uncertainties are also reduced by 40% and 30% respectively. We also find that the accuracy of velocity field reconstruction depends strongly on the smoothing scale used for the density field. We measure the bias and uncertainties associated with different choices of smoothing length.
Salazar-Albornoz, Salvador; Grieb, Jan Niklas; Crocce, Martin; Scoccimarro, Roman; Alam, Shadab; Beutler, Florian; Brownstein, Joel R; Chuang, Chia-Hsun; Kitaura, Francisco-Shu; Olmstead, Matthew D; Percival, Will J; Prada, Francisco; Rodríguez-Torres, Sergio; Samushia, Lado; Tinker, Jeremy; Thomas, Daniel; Tojeiro, Rita; Wang, Yuting; Zhao, Gong-bo
2016-01-01
We investigate the cosmological implications of studying galaxy clustering using a tomographic approach applied to the final BOSS DR12 galaxy sample, including both auto- and cross-correlation functions between redshift shells. We model the signal of the full shape of the angular correlation function, $\\omega(\\theta)$, in redshift bins using state-of-the-art modelling of non-linearities, bias and redshift-space distortions. We present results on the redshift evolution of the linear bias of BOSS galaxies, which cannot be obtained with traditional methods for galaxy-clustering analysis. We also obtain constraints on cosmological parameters, combining this tomographic analysis with measurements of the cosmic microwave background (CMB) and type Ia supernova (SNIa). We explore a number of cosmological models, including the standard $\\Lambda$CDM model and its most interesting extensions, such as deviations from $w_\\rm{DE} = -1$, non-minimal neutrino masses, spatial curvature and deviations from general relativity u...
Ogilvy, Stephen
2015-01-01
The vast amount of $c\\overline{c}$ production that can be recorded by the LHCb detector makes it an ideal environment to study the hadronic production of charmed baryons, along with the properties of their decays. We briefly describe the LHCb experiment and the triggering mechanisms it uses for recording charm production. Previous charmed baryon results from LHCb are detailed, with a description of the future plans for the charmed baryon programme.
Naik, Paras
2016-01-01
The LHCb detector is an excellent instrument for studying the production and decay of charmed baryons in $pp$ collisions, due to efficient triggering mechanisms that capture the copious production of $c\\overline{c}$ at the Large Hadron Collider. The LHCb experiment and its charmed baryon results from LHCb are detailed, with a description of our future plans.
Kubis, B; Meißner, Ulf G; Mei{\\ss}ner, Ulf-G.
1999-01-01
We calculate the form factors of the baryon octet in the framework of heavy baryon chiral perturbation theory. The calculated charge radius of the show that kaon loop effects can play a significant role in the neutron electric form factor. Furthermore. we derive generalized Caldi-Pagels relations between various charge radii which are free of chiral loop effects.
Baryogenesis via Particle-Antiparticle Oscillations
Ipek, Seyda
2016-01-01
CP violation, which is crucial for producing the baryon asymmetry of the Universe, is enhanced in particle-antiparticle oscillations. We study particle-antiparticle oscillations (of a particle with mass O(100 GeV)) with CP violation in the early Universe in the presence of interactions with O(ab-fb) cross-sections. We show that, if baryon-number-violating interactions exist, a baryon asymmetry can be produced via out-of-equilibrium decays of oscillating particles. As a concrete example we study a $U(1)_R$-symmetric, R-parity-violating SUSY model with pseudo-Dirac gauginos, which undergo particle-antiparticle oscillations. Taking bino to be the lightest $U(1)_R$-symmetric particle, and assuming it decays via baryon-number-violating interactions, we show that bino-antibino oscillations can produce the baryon asymmetry of the Universe.
Charmed baryons on the lattice
Padmanath, M
2015-01-01
We discuss the significance of charm baryon spectroscopy in hadron physics and review the recent developments of the spectra of charmed baryons in lattice calculations. Special emphasis is given on the recent studies of highly excited charm baryon states. Recent precision lattice measurements of the low lying charm and bottom baryons are also reviewed.
Indian Academy of Sciences (India)
Torsten Leddig
2012-11-01
From inclusive measurements, it is known that about 7% of all mesons decay into final states with baryons. In these decays, some striking features become visible compared to mesonic decays. The largest branching fractions come with quite moderate multiplicities of 3–4 hadrons. We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon–antibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.
Page, P R
2000-01-01
We discuss whether a low-lying hybrid baryon should be defined as a three quark - gluon bound state or as three quarks moving on an excited adiabatic potential. We show that the latter definition becomes exact, not only for very heavy quarks, but also for specific dynamics. We review the literature on the signatures of hybrid baryons, with specific reference to strong hadronic decays, electromagnetic couplings, diffractive production and production in psi decay.
Institute of Scientific and Technical Information of China (English)
詹想; 崔建华; 王宝泉; 翟忠旭; 张同杰
2014-01-01
Radial Baryon Acoustic Oscillation (RBAO)measurements,distant type Ia supernovae (SNe Ia),the observational H(z)data (OHD)and the Cosmic Microwave Background (CMB)shift parameter data are used to constrain cosmological parameters ofΛCDM and XCDM cosmologies and to further examine the role of OHD and SNe Ia data in cosmological constraints.The likelihood function over h is marginalized by integrating the probability density P∝e(-χ2/2)to obtain best fitting results and confidence regions in theΩm-ΩΛplane.Combination analysis for bothΛCDM and XCDM models reveal that confidence regions of 68.3%, 95.4% and 99.7% levels using OHD+RBAO+CMB data are in good agreement with that of SNe Ia+RBAO+CMB data which is consistent with data from Lin et al.(2009).With more OHD data,it may be possible to constrain cosmological parameters using OHD data instead of SNe Ia data in the future.%使用径向重子声学振荡(RBAO)测量遥远的 Ia型超新星(SNe Ia)、观测哈勃参量数据(OHD)和宇宙微波背景(CMB)位移参数数据来限制ΛCDM和 XCDM宇宙的宇宙学参量,进一步检查了 OHD和 SNe Ia 数据对宇宙学的约束作用.我们对似然函数的归化哈勃参数h进行了边缘化,即积分概率密度P∝e-Χ2/2,以在Ωm-ΩΛ平面获得最佳的拟合结果和置信区域.依据ΛCDM和 XCDM模型的组合分析,我们发现在置信区域为68.3%、95.4%和99.7%的置信水平上,OHD+RBAO+CMB数据和 SNe Ia+RBAO+CMB数据符合得很好.随着越来越多的 OHD数据的获得,我们或许在将来可以使用 OHD数据代替 SNe Ia数据来限制宇宙学参量.
The Dark Energy Spectroscopic Instrument (DESI)
Flaugher, Brenna; Bebek, Chris
2014-07-01
The Dark Energy Spectroscopic Instrument (DESI) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar spectroscopic redshift survey. The DESI instrument consists of a new wide-field (3.2 deg. linear field of view) corrector plus a multi-object spectrometer with up to 5000 robotically positioned optical fibers and will be installed at prime focus on the Mayall 4m telescope at Kitt Peak, Arizona. The fibers feed 10 three-arm spectrographs producing spectra that cover a wavelength range from 360-980 nm and have resolution of 2000-5500 depending on the wavelength. The DESI instrument is designed for a 14,000 sq. deg. multi-year survey of targets that trace the evolution of dark energy out to redshift 3.5 using the redshifts of luminous red galaxies (LRGs), emission line galaxies (ELGs) and quasars. DESI is the successor to the successful Stage-III BOSS spectroscopic redshift survey and complements imaging surveys such as the Stage-III Dark Energy Survey (DES, currently operating) and the Stage-IV Large Synoptic Survey Telescope (LSST, planned start early in the next decade).
Baryon Spectroscopy and Resonances
Energy Technology Data Exchange (ETDEWEB)
Robert Edwards
2011-12-01
A short review of current efforts to determine the highly excited state spectrum of QCD, and in particular baryons, using lattice QCD techniques is presented. The determination of the highly excited spectrum of QCD is a major theoretical and experimental challenge. The experimental investigation of the excited baryon spectrum has been a long-standing element of the hadronic-physics program, an important component of which is the search for so-called 'missing resonances', baryonic states predicted by the quark model based on three constituent quarks but which have not yet been observed experimentally. Should such states not be found, it may indicate that the baryon spectrum can be modeled with fewer effective degrees of freedom, such as in quark-diquark models. In the past decade, there has been an extensive program to collect data on electromagnetic production of one and two mesons at Jefferson Lab, MIT-Bates, LEGS, MAMI, ELSA, and GRAAL. To analyze these data, and thereby refine our knowledge of the baryon spectrum, a variety of physics analysis models have been developed at Bonn, George Washington University, Jefferson Laboratory and Mainz. To provide a theoretical determination and interpretation of the spectrum, ab initio computations within lattice QCD have been used. Historically, the calculation of the masses of the lowest-lying states, for both baryons and mesons, has been a benchmark calculation of this discretized, finite-volume computational approach, where the aim is well-understood control over the various systematic errors that enter into a calculation; for a recent review. However, there is now increasing effort aimed at calculating the excited states of the theory, with several groups presenting investigations of the low-lying excited baryon spectrum, using a variety of discretizations, numbers of quark flavors, interpolating operators, and fitting methodologies. Some aspects of these calculations remain unresolved and are the subject of
Charmed Bottom Baryon Spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Brown, Zachary S; Detmold, William; Meinel, Stefan; Orginos, Kostas
2014-11-01
The spectrum of doubly and triply heavy baryons remains experimentally unexplored to a large extent. Although the detection of such heavy particle states may lie beyond the reach of exper- iments for some time, it is interesting compute this spectrum from QCD and compare results between lattice calculations and continuum theoretical models. Several lattice calculations ex- ist for both doubly and triply charmed as well as doubly and triply bottom baryons. Here, we present preliminary results from the first lattice calculation of doubly and triply heavy baryons including both charm and bottom quarks. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. We present preliminary results for the ground state spectrum.
Baryonic Spectroscopy at BESIII
Liu, Fang
Based on 106 million Ψ(3686) events collected with BESIII detector at BEPCII, some results on excited baryons from the partial wave analysis are presented. In the decay of ψ(3686) to pbar{p}π 0, two new baryonic excited states, Jpc = 1/2 + N(2300) and Jpc = 5/2 - N(2570) are significant, and additional 5 well known N* excited states are observed. In ψ(3686) to pbar{p}η , an excited-nucleon state N(1535) is dominant. In ψ(3686) to K - Λ bar{Ξ} + + c.c., two hyperons Ξ(1690) and Ξ(1820) are observed. In ψ(3686) to Λ bar{Σ }π + c.c., some excited strange baryons bar{Λ }* and Σ* are measured on the Σ+π- and Λπ- mass spectra.
Liu, Keh-Fei
2016-01-01
The relevance of chiral symmetry in baryons is highlighted in three examples in the nucleon spectroscopy and structure. The first one is the importance of chiral dynamics in understanding the Roper resonance. The second one is the role of chiral symmetry in the lattice calculation of $\\pi N \\sigma$ term and strangeness. The third one is the role of chiral $U(1)$ anomaly in the anomalous Ward identity in evaluating the quark spin and the quark orbital angular momentum. Finally, the chiral effective theory for baryons is discussed.
(Hybrid) Baryons Symmetries and Masses
Page, P R
1999-01-01
We construct (hybrid) baryons in the flux-tube model of Isgur and Paton. In the limit of adiabatic quark motion, we build proper eigenstates of orbital angular momentum and construct the flavour, spin and J^P of hybrid baryons from the symmetries of the system. The lowest mass hybrid baryon is estimated at approximately 2 GeV.
Problems in baryon spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Capstick, S. [Florida State Univ., Tallahassee, FL (United States)
1994-04-01
Current issues and problems in the physics of ground- and excited-state baryons are considered, and are classified into those which should be resolved by CEBAF in its present form, and those which may require CEBAF to undergo an energy upgrade to 8 GeV or more. Recent theoretical developments designed to address these problems are outlined.
Spontaneous Baryogenesis without Baryon Isocurvature
De Simone, Andrea
2016-01-01
We propose a new class of spontaneous baryogenesis models that does not produce baryon isocurvature perturbations. The baryon chemical potential in these models is independent of the field value of the baryon-generating scalar, hence the scalar field fluctuations are blocked from propagating into the baryon isocurvature. We demonstrate this mechanism in simple examples where spontaneous baryogenesis is driven by a non-canonical scalar field. The suppression of the baryon isocurvature allows spontaneous baryogenesis to be compatible even with high-scale inflation.
Combining Spectroscopic and Photometric Surveys: Same or different sky?
Eriksen, Martin
2014-01-01
This article looks at the combined constraints from a photometric and spectroscopic survey. These surveys will measure cosmology using weak lensing (WL), galaxy cluster- ing, baryon acoustic oscillations (BAO) and redshift space distortions (RSD). We find, contrary to some findings in the recent literature, that overlapping surveys can give important benefits when measuring dark energy. We therefore try to clarify the status of this issue with a full forecast of two stage-IV surveys using a new approach to prop- erly account for covariance between the different probes in the overlapping samples. The benefit of the overlapping survey can be traced back to two factors: additional observables and sample variance cancellation. Both needs to be taken into account and contribute equally when combining 3D power spectrum and 2D correlations for lensing. With an analytic example we also illustrate that for optimal constraints, one should minimize the (Pearson) correlation coefficient between cosmological and nui- sanc...
Excited state mass spectra of singly charmed baryons
Energy Technology Data Exchange (ETDEWEB)
Shah, Zalak; Kumar Rai, Ajay [Sardar Vallabhbhai National Institute of Technology, Department of Applied Physics, Surat, Gujarat (India); Thakkar, Kaushal [GIDC Degree Engineering College, Department of Applied Sciences and Humanities, Abrama (India); Vinodkumar, P.C. [Sardar Patel University, Department of Physics, V.V. Nagar (India)
2016-10-15
Mass spectra of excited states of the singly charmed baryons are calculated using the hypercentral description of the three-body system. The baryons consist of a charm quark and light quarks (u, d and s) are studied in the framework of QCD motivated constituent quark model. The form of the confinement potential is hyper-Coloumb plus power potential with potential index ν, varying from 0.5 to 2.0. The first-order correction to the confinement potential is also incorporated in this approach. The radial as well as orbital excited state masses of Σ{sub c}{sup ++}, Σ{sub c}{sup +}, Σ{sub c}{sup 0}, Ξ{sub c}{sup +}, Ξ{sub c}{sup 0}, Λ{sub c}{sup +}, Ω{sub c}{sup 0} baryons, are reported in this paper. We have incorporated spin-spin, spin-orbit and tensor interactions perturbatively in the present study. The semi-electronic decay of Ω{sub c} and Ξ{sub c} are also calculated using the spectroscopic parameters of these baryons. The computed results are compared with other theoretical predictions as well as with the available experimental observations. We also construct the Regge trajectory in (n{sub r},M{sup 2}) and (J,M{sup 2}) planes for these baryons. (orig.)
Soberman, R K; Soberman, Robert K.; Dubin, Maurice
2001-01-01
A comet-like, but magnitudes smaller, extremely low albedo interstellar meteoroid population of fragile aggregates with solar type composition, measured in space and terrestrially, is most probably the universal dark matter. Although non-baryonic particles cannot be excluded, only "Big Bang" cosmology predicts an appreciable fraction of such alternate forms. As more counter-physics hypotheses are added to fit observation to the expanding universe assumption, a classical physics alternative proffers dark matter interactive red shifts normally correlated with distance. The cosmic microwave background results from size-independent thermal plateau radiation that emanates from dark matter gravitationally drawn into the Galaxy.
Dynamical Structure of Baryons
Aleksejevs, A
2013-01-01
Compton scattering offers a unique opportunity to study the dynamical structure of hadrons over a wide kinematic range, with polarizabilities characterizing the hadron active internal degrees of freedom. We present calculations and detailed analysis of electric and magnetic and the spin-dependent dynamical polarizabilities for the lowest in mass SU(3) octet of baryons. These extensive calculations are made possible by the recent implementation of semi-automatized calculations in chiral perturbation theory which allows evaluating polarizabilities from Compton scattering up to next-to-the-leading order. The dependencies for the range of photon energies covering the majority of the meson photoproduction channels are analyzed.
Pati, Jogesh C.; Salam, Abdus
We suggest that baryon-number conservation may not be absolute and that an integrally charged quark may disintegrate into two leptons and an antilepton with a coupling strength G Bmp2≲ 10-9. On the other hand, if quarks are much heavier than low-lying hadrons, the decay of a three-quark system like the proton is highly forbidden (proton lifetime ≳ 1028 y). Motivation for these ideas appears to arise within a unified theory of hadrons and leptons and their gauge interactions. We emphasize the consequences of such a possibility for real quark searches.
Stochastic isocurvature baryon fluctuations, baryon diffusion, and primordial nucleosynthesis
Kurki-Suonio, H; Mathews, G J; Kurki-Suonio, Hannu; Jedamzik, Karsten; Mathews, Grant J
1996-01-01
We examine effects on primordial nucleosynthesis from a truly random spatial distribution in the baryon-to-photon ratio (\\eta). We generate stochastic fluctuation spectra characterized by different spectral indices and root-mean-square fluctuation amplitudes. For the first time we explicitly calculate the effects of baryon diffusion on the nucleosynthesis yields of such stochastic fluctuations. We also consider the collapse instability of large-mass-scale inhomogeneities. Our results are generally applicable to any primordial mechanism producing fluctuations in \\eta which can be characterized by a spectral index. In particular, these results apply to primordial isocurvature baryon fluctuation (PIB) models. The amplitudes of scale-invariant baryon fluctuations are found to be severely constrained by primordial nucleosynthesis. However, when the \\eta distribution is characterized by decreasing fluctuation amplitudes with increasing length scale, surprisingly large fluctuation amplitudes on the baryon diffusion ...
Anomalous Dimensions of Conformal Baryons
DEFF Research Database (Denmark)
Pica, Claudio; Sannino, Francesco
2016-01-01
We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within...
Bijker, R; Leviatan, A
1993-01-01
We propose an algebraic description of the geometric structure of baryons in terms of the algebra $U(7)$. We construct a mass operator that preserves the threefold permutational symmetry and discuss a collective model of baryons with the geometry of an oblate top.
Anomalous Dimensions of Conformal Baryons
DEFF Research Database (Denmark)
Pica, Claudio; Sannino, Francesco
2016-01-01
We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within the $...
Primordial Lepton Oscillations and Baryogenesis
Hamada, Yuta
2016-01-01
The baryon asymmetry of the Universe should have been produced after the inflation era. We consider the possibility that the asymmetry is generated by the flavor oscillations in the reheating process after inflation, so that the baryon asymmetry is realized already at the beginning of the radiation dominated era. In the seesaw model, we show that the propagators of the left-handed leptons generically have flavor mixings in the thermal background, that can generate flavor-dependent lepton asymmetry through the $CP$ violation in the oscillation phenomena. The flavor dependent rates for the wash-out process can leave the net asymmetry today.
Primordial lepton oscillations and baryogenesis
Hamada, Yuta; Kitano, Ryuichiro
2016-11-01
The baryon asymmetry of the Universe should have been produced after the inflation era. We consider the possibility that the asymmetry is generated by the flavor oscillations in the reheating process after inflation, so that the baryon asymmetry is realized already at the beginning of the radiation dominated era. In the seesaw model, we show that the propagators of the left-handed leptons generically have flavor mixings in the thermal background, that can generate flavor-dependent lepton asymmetry through the CP violation in the oscillation phenomena. The flavor dependent rates for the wash-out process can leave the net asymmetry today.
Baryon stopping probes deconfinement
Wolschin, Georg
2016-08-01
Stopping and baryon transport in central relativistic Pb + Pb and Au + Au collisions are reconsidered with the aim to find indications for the transition from hadronic to partonic processes. At energies reached at the CERN Super Proton Synchrotron ( √{s_{NN}} = 6.3-17.3 GeV) and at RHIC (62.4 GeV) the fragmentation-peak positions as obtained from the data depend linearly on the beam rapidity and are in agreement with earlier results from a QCD-based approach that accounts for gluon saturation. No discontinuities in the net-proton fragmentation peak positions occur in the expected transition region from partons to hadrons at 6-10GeV. In contrast, the mean rapidity loss is predicted to depend linearly on the beam rapidity only at high energies beyond the RHIC scale. The combination of both results offers a clue for the transition from hard partonic to soft hadronic processes in baryon stopping. NICA results could corroborate these findings.
Electromagnetic properties of baryons
Energy Technology Data Exchange (ETDEWEB)
Haupt, C.
2006-07-01
Static observables of bound state systems in field theoretic descriptions are usually extracted from form factors in the limit of vanishing squared four-momentum transfer of the probing exchange particle. On the other hand, static properties in nonrelativistic quantum mechanics can be formulated by means of expectation values involving essentially scalar products of wave functions. The main objective of this work is to show that a synthesis of both approaches is indeed possible - at least if certain restrictions are made to the kind of interactions between the constituents of the bound system - leading to new insights into the structure of static properties. The focus lies especially on the charge radii and magnetic moments of baryons described within a covariant constituent quark model having its field theoretic foundations in the Bethe-Salpeter equation. The current matrix element in the Breit frame between the vertex functions is derived. The charge radius and magnetic moment of a bound three-fermion system is then derived by starting from their usual definition from form factors and in case of the charge radius also from the well-known radius of a charge distribution in classical electrodynamics. In both cases the static limit at the photon point is taken analytically and subsequently the integration over the relative energy variables is done. Finally the vertex functions are replaced by Salpeter amplitudes and the expression is symmetrized over the three fermions. The final results express the charge radius and magnetic moment of the three-fermion system as expectation values with respect to Salpeter amplitudes. The numerical implementation of the analytic results is done within a covariant constituent quark model with quark confinement and a residual instanton interaction accounting for the fine structure of the observed mass spectra. The Salpeter amplitudes which where obtained by solving the Salpeter equation are used to compute the expectation values of
Progress Toward Understanding Baryon Resonances
Crede, Volker
2013-01-01
The composite nature of baryons manifests itself in the existence of a rich spectrum of excited states, in particular in the important mass region 1-2 GeV for the light-flavoured baryons. The properties of these resonances can be identified by systematic investigations using electromagnetic and strong probes, primarily with beams of electrons, photons, and pions. After decades of research, the fundamental degrees of freedom underlying the baryon excitation spectrum are still poorly understood. The search for hitherto undiscovered but predicted resonances continues at many laboratories around the world. Recent results from photo- and electroproduction experiments provide intriguing indications for new states and shed light on the structure of some of the known nucleon excitations. The continuing study of available data sets with consideration of new observables and improved analysis tools have also called into question some of the earlier findings in baryon spectroscopy. Other breakthrough measurements have be...
Anomalous Dimensions of Conformal Baryons
Pica, Claudio
2016-01-01
We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small for a wide range of number of flavours. We also find that this is always smaller than the anomalous dimension of the fermion mass operator. These findings challenge the partial compositeness paradigm.
Algebraic Approach to Baryon Structure
Leviatan, A
1996-01-01
We present an algebraic approach to the internal structure of baryons in terms of three constituents. We investigate a collective model in which the nucleon is regarded as a rotating and vibrating oblate top with a prescribed distribution of charges and magnetization. We contrast the collective and single-particle descriptions of baryons and compare the predictions of the model with existing data on masses, electromagnetic elastic and transition form factors and strong decays widths.
Baryon spectrum and chiral dynamics
Glozman, L Ya
1995-01-01
New results on baryon structure and spectrum developed in collaboration with Dan Riska [1-4] are reported. The main idea is that beyond the chiral symmetry spontaneous breaking scale light and strange baryons should be considered as systems of three constituent quarks with an effective confining interaction and a chiral interaction that is mediated by the octet of Goldstone bosons (pseudoscalar mesons) between the constituent quarks.
Galaxy Cluster Baryon Fractions Revisited
Gonzalez, Anthony H; Zabludoff, Ann I; Zaritsky, Dennis
2013-01-01
We measure the baryons contained in both the stellar and hot gas components for twelve galaxy clusters and groups at z~0.1 with M=1-5e14 Msun. This paper improves upon our previous work through the addition of XMM data, enabling measurements of the total mass and masses of each major baryonic component --- ICM, intracluster stars, and stars in galaxies --- for each system. We recover a relation for the stellar mass versus halo mass consistent with our previous result. We confirm that the partitioning of baryons between the stellar and hot gas components is a strong function of M500; the fractions of total mass in stars and X-ray gas within r500 scale as M500^-0.45 and M500^0.26, respectively. We also confirm that the combination of the BCG and intracluster stars is an increasingly important contributor to the stellar baryon budget in lower halo masses. We find a weak, but statistically significant, dependence of the total baryon fraction upon halo mass, scaling as M500^0.16. For M500>2e14, the total baryon fr...
Tian, Hui; McIntosh, Scott W.; Wang, Tongjiang; Offman, Leon; De Pontieu, Bart; Innes, Davina E.; Peter, Hardi
2012-01-01
Using data obtained by the EUV Imaging Spectrometer on board Hinode, we have performed a survey of obvious and persistent (without significant damping) Doppler shift oscillations in the corona. We have found mainly two types of oscillations from February to April in 2007. One type is found at loop footpoint regions, with a dominant period around 10 minutes. They are characterized by coherent behavior of all line parameters (line intensity, Doppler shift, line width, and profile asymmetry), and apparent blueshift and blueward asymmetry throughout almost the entire duration. Such oscillations are likely to be signatures of quasi-periodic upflows (small-scale jets, or coronal counterpart of type-II spicules), which may play an important role in the supply of mass and energy to the hot corona. The other type of oscillation is usually associated with the upper part of loops. They are most clearly seen in the Doppler shift of coronal lines with formation temperatures between one and two million degrees. The global wavelets of these oscillations usually peak sharply around a period in the range of three to six minutes. No obvious profile asymmetry is found and the variation of the line width is typically very small. The intensity variation is often less than 2%. These oscillations are more likely to be signatures of kink/Alfv´en waves rather than flows. In a few cases, there seems to be a p/2 phase shift between the intensity and Doppler shift oscillations, which may suggest the presence of slow-mode standing waves according to wave theories. However, we demonstrate that such a phase shift could also be produced by loops moving into and out of a spatial pixel as a result of Alfv´enic oscillations. In this scenario, the intensity oscillations associated with Alfv´enic waves are caused by loop displacement rather than density change. These coronal waves may be used to investigate properties of the coronal plasma and magnetic field.
Molecular dynamics simulation for the baryon-quark phase transition at finite baryon density
Energy Technology Data Exchange (ETDEWEB)
Akimura, Y. [Saitama University, Department of physics, Sakura-Ku, Saitama City (Japan); Japan Atomic Energy Research Institute, Advanced Science Research Center, Tokai (Japan); Maruyama, T.; Chiba, S. [Japan Atomic Energy Research Institute, Advanced Science Research Center, Tokai (Japan); Yoshinaga, N. [Saitama University, Department of physics, Sakura-Ku, Saitama City (Japan)
2005-09-01
We study the baryon-quark phase transition in the molecular dynamics (MD) of the quark degrees of freedom at finite baryon density. The baryon state at low baryon density, and the deconfined quark state at high baryon density are reproduced. We investigate the equations of state of matters with different u-d-s compositions. It is found that the baryon-quark transition is sensitive to the quark width. (orig.)
The Dark Energy Spectroscopic Instrument (DESI): Science from the DESI Survey
Eisenstein, Daniel; DESI Collaboration
2015-01-01
The Dark Energy Spectroscopic Instrument (DESI) will enable an ambitious redshift survey to probe dark energy by the baryon acoustic oscillation and redshift-space distortion methods. The same data set will serve numerous other goals in cosmology and astrophysics. Using a new 5000-fiber instrument and 8 square degree field of view at the Mayall telescope, the DESI survey plans to cover 14,000 square degrees and about 25 million high-redshift objects. The targets include 4M luminous red galaxies (redshift 0.4-1.0), 18M emission line galaxies (redshift 0.6-1.6), and 2.4M quasars, including 0.7M Lyman-alpha forest sight lines. With this, DESI can map the expansion history of the Universe to redshift 3, achieving unprecedented performance from the baryon acoustic oscillation method. We will describe the present state of the survey design and the cosmological forecasts for dark energy, inflation, and neutrino physics. We also give an update on the DESI Science Collaboration.
Baryons and baryonic matter in four-fermion interaction models
Energy Technology Data Exchange (ETDEWEB)
Urlichs, K.
2007-02-23
In this work we discuss baryons and baryonic matter in simple four-fermion interaction theories, the Gross-Neveu model and the Nambu-Jona-Lasinio model in 1+1 and 2+1 space-time dimensions. These models are designed as toy models for dynamical symmetry breaking in strong interaction physics. Pointlike interactions (''four-fermion'' interactions) between quarks replace the full gluon mediated interaction of quantum chromodynamics. We consider the limit of a large number of fermion flavors, where a mean field approach becomes exact. This method is formulated in the language of relativistic many particle theory and is equivalent to the Hartree-Fock approximation. In 1+1 dimensions, we generalize known results on the ground state to the case where chiral symmetry is broken explicitly by a bare mass term. For the Gross-Neveu model, we derive an exact self-consistent solution for the finite density ground state, consisting of a one-dimensional array of equally spaced potential wells, a baryon crystal. For the Nambu- Jona-Lasinio model we apply the derivative expansion technique to calculate the total energy in powers of derivatives of the mean field. In a picture akin to the Skyrme model of nuclear physics, the baryon emerges as a topological soliton. The solution for both the single baryon and dense baryonic matter is given in a systematic expansion in powers of the pion mass. The solution of the Hartree-Fock problem is more complicated in 2+1 dimensions. In the massless Gross-Neveu model we derive an exact self-consistent solution by extending the baryon crystal of the 1+1 dimensional model, maintaining translational invariance in one spatial direction. This one-dimensional configuration is energetically degenerate to the translationally invariant solution, a hint in favor of a possible translational symmetry breakdown by more general geometrical structures. In the Nambu-Jona-Lasinio model, topological soliton configurations induce a finite baryon
SPIDERS: the spectroscopic follow-up of X-ray selected clusters of galaxies in SDSS-IV
Clerc, Nicolas; Zhang, Yu-Ying; Finoguenov, Alexis; Dwelly, Tom; Nandra, Kirpal; Collins, Chris A; Dawson, Kyle; Kneib, Jean-Paul; Rozo, Eduardo; Rykoff, Eli; Sadibekova, Tatyana; Brownstein, Joel R; Lin, Yen-Ting; Ridl, Jethro; Salvato, Mara; Schwope, Axel; Steinmetz, Matthias; Seo, Hee-Jong; Tinker, Jeremy
2016-01-01
SPIDERS (The SPectroscopic IDentification of eROSITA Sources) is a program dedicated to the homogeneous and complete spectroscopic follow-up of X-ray AGN and galaxy clusters over a large area ($\\sim$7500 deg$^2$) of the extragalactic sky. SPIDERS is part of the SDSS-IV project, together with the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) and the Time-Domain Spectroscopic Survey (TDSS). This paper describes the largest project within SPIDERS before the launch of eROSITA: an optical spectroscopic survey of X-ray selected, massive ($\\sim 10^{14}$ to $10^{15}~M_{\\odot}$) galaxy clusters discovered in ROSAT and XMM-Newton imaging. The immediate aim is to determine precise ($\\Delta_z \\sim 0.001$) redshifts for 4,000-5,000 of these systems out to $z \\sim 0.6$. The scientific goal of the program is precision cosmology, using clusters as probes of large-scale structure in the expanding Universe. We present the cluster samples, target selection algorithms and observation strategies. We demonstrate the eff...
Quark confinement mechanism for baryons
Goncharov, Yu P
2013-01-01
The confinement mechanism proposed earlier and then successfully applied to meson spectroscopy by the author is extended over baryons. For this aim the wave functions of baryons are built as tensorial products of those corresponding to the 2-body problem underlying the confinement mechanism of two quarks. This allows one to obtain the Hamiltonian of the quark interactions in a baryon and, accordingly, the possible energy spectrum of the latter. Also one may construct the electric and magnetic form factors of baryon in a natural way which entails the expressions for the root-mean-square radius and anomalous magnetic moment. To ullustrate the formalism in the given Chapter for the sake of simplicity only symmetrical baryons (i.e., composed from three quarks of the same flavours) $\\Delta^{++}$, $\\Delta^{-}$, $\\Omega^-$ are considered. For them the masses, the root-mean-square radii and anomalous magnetic moments are expressed in an explicit analytical form through the parameters of the confining SU(3)-gluonic fi...
Baryon Transition in Holographic QCD
Li, Siwen
2015-01-01
We propose a mechanism of holographic baryon transition in the Sakai-Sugimoto (SS) model: baryons in this model can jump to different states under the mediated effect of gravitons (or glueballs by holography). We consider a time-dependent gravitational perturbation from M5-brane solution of D=11 supergravity and by employing the relations between 11D M-theory and IIA string theory, we get its 10 dimensional counterpart in the SS model. Such a perturbation is received by the D4-branes wrapped on the $S^{4}$ part of the 10D background, namely the baryon vertex. Technically, baryons in the SS model are described by BPST instanton ansatz and their dynamics can be analyzed using the quantum mechanical system in the instanton's moduli space. In this way, different baryonic states are marked by quantum numbers of moduli space quantum mechanics. By holographic spirit, the gravitational perturbation enters the Hamiltonian as a time-dependent perturbation and it is this time-dependent perturbative Hamiltonian produces ...
THE TIME DOMAIN SPECTROSCOPIC SURVEY: VARIABLE SELECTION AND ANTICIPATED RESULTS
Energy Technology Data Exchange (ETDEWEB)
Morganson, Eric; Green, Paul J. [Harvard Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Anderson, Scott F.; Ruan, John J. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Eracleous, Michael; Brandt, William Nielsen [Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Kelly, Brandon [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106-9530 (United States); Badenes, Carlos [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O’Hara St, Pittsburgh, PA 15260 (United States); Bañados, Eduardo [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Blanton, Michael R. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Bershady, Matthew A. [Department of Astronomy, University of Wisconsin, 475 N. Charter St., Madison, WI 53706 (United States); Borissova, Jura [Instituto de Física y Astronomía, Universidad de Valparaíso, Av. Gran Bretaña 1111, Playa Ancha, Casilla 5030, and Millennium Institute of Astrophysics (MAS), Santiago (Chile); Burgett, William S. [GMTO Corp, Suite 300, 251 S. Lake Ave, Pasadena, CA 91101 (United States); Chambers, Kenneth, E-mail: emorganson@cfa.harvard.edu [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); and others
2015-06-20
We present the selection algorithm and anticipated results for the Time Domain Spectroscopic Survey (TDSS). TDSS is an Sloan Digital Sky Survey (SDSS)-IV Extended Baryon Oscillation Spectroscopic Survey (eBOSS) subproject that will provide initial identification spectra of approximately 220,000 luminosity-variable objects (variable stars and active galactic nuclei across 7500 deg{sup 2} selected from a combination of SDSS and multi-epoch Pan-STARRS1 photometry. TDSS will be the largest spectroscopic survey to explicitly target variable objects, avoiding pre-selection on the basis of colors or detailed modeling of specific variability characteristics. Kernel Density Estimate analysis of our target population performed on SDSS Stripe 82 data suggests our target sample will be 95% pure (meaning 95% of objects we select have genuine luminosity variability of a few magnitudes or more). Our final spectroscopic sample will contain roughly 135,000 quasars and 85,000 stellar variables, approximately 4000 of which will be RR Lyrae stars which may be used as outer Milky Way probes. The variability-selected quasar population has a smoother redshift distribution than a color-selected sample, and variability measurements similar to those we develop here may be used to make more uniform quasar samples in large surveys. The stellar variable targets are distributed fairly uniformly across color space, indicating that TDSS will obtain spectra for a wide variety of stellar variables including pulsating variables, stars with significant chromospheric activity, cataclysmic variables, and eclipsing binaries. TDSS will serve as a pathfinder mission to identify and characterize the multitude of variable objects that will be detected photometrically in even larger variability surveys such as Large Synoptic Survey Telescope.
Fujiwara, Y; Suzuki, Y
2006-01-01
We calculate Lambda alpha, Sigma alpha and Xi alpha potentials from the nuclear-matter G-matrices of the SU6 quark-model baryon-baryon interaction. The alpha-cluster wave function is assumed to be a simple harmonic-oscillator shell-model wave function. A new method is proposed to derive the direct and knock-on terms of the interaction Born kernel from the hyperon-nucleon G-matrices, with explicit treatments of the nonlocality and the center-of-mass motion between the hyperon and alpha. We find that the SU6 quark-model baryon-baryon interactions, FSS and fss2, yield a reasonable bound-state energy for 5 He Lambda, -3.18 -- -3.62 MeV, in spite of the fact that they give relatively large depths for the Lambda single-particle potentials, 46 -- 48 MeV, in symmetric nuclear matter. An equivalent local potential derived from the Wigner transform of the nonlocal Lambda alpha kernel shows a strong energy dependence for the incident Lambda-particle, indicating the importance of the strangeness-exchange process in the o...
Baryon Number Violating Scalar Diquarks at the LHC
Baldes, Iason; Volkas, Raymond R
2011-01-01
Baryon number violating (BNV) processes are heavily constrained by experiments searching for nucleon decay and neutron-antineutron oscillations. If the baryon number violation occurs via the third generation quarks, however, we may be able to avoid the nucleon stability constraints, thus making such BNV interactions accessible at the LHC. In this paper we study a specific class of BNV extensions of the standard model (SM) involving diquark and leptoquark scalars. After an introduction to these models we study one promising extension in detail, being interested in particles with mass of O(TeV). We calculate limits on the masses and couplings from neutron-antineutron oscillations and dineutron decay for couplings to first and third generation quarks. We explore the possible consequences of such a model on the matter-antimatter asymmetry. We shall see that for models which break the global baryon minus lepton number symmetry, (B-L), the most stringent constraints come from the need to preserve a matter-antimatte...
Density-dependent effective baryon-baryon interaction from chiral three-baryon forces
Petschauer, Stefan; Haidenbauer, Johann; Kaiser, Norbert; Meißner, Ulf-G.; Weise, Wolfram
2017-01-01
A density-dependent effective potential for the baryon-baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon-nucleon interaction. Explicit expressions for the ΛN in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the three-body force in symmetric nuclear matter and pure neutron matter on the ΛN interaction. A moderate repulsion that increases with density is found in comparison to the free ΛN interaction.
Density-dependent effective baryon-baryon interaction from chiral three-baryon forces
Petschauer, Stefan; Kaiser, Norbert; Meißner, Ulf-G; Weise, Wolfram
2016-01-01
A density-dependent effective potential for the baryon-baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon-nucleon interaction. Explicit expressions for the Lambda-nucleon in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the ...
Dilatons in Dense Baryonic Matter
Lee, Hyun Kyu
2013-01-01
We discuss the role of dilaton, which is supposed to be representing a special feature of scale symmetry of QCD, trace anomaly, in dense baryonic matter. The idea that the scale symmetry breaking of QCD is responsible for the spontaneous breaking of chiral symmetry is presented along the similar spirit of Freund-Nambu model. The incorporation of dilaton field in the hidden local symmetric parity doublet model is briefly sketched with the possible role of dilaton at high density baryonic matter, the emergence of linear sigma model in dilaton limit.
Decuplet baryons in hot medium
Azizi, K
2016-01-01
The thermal properties of the light decuplet baryons are investigated in the framework of the thermal QCD sum rules. In particular, the behavior of the mass and residue of the $\\Delta$, $\\Sigma^{*}$, $\\Xi^{*}$ and $\\Omega$ baryons with respect to temperature are analyzed taking into account the additional operators coming up in the Wilson expansion at finite temperature. It is found that the mass and residue of these particles remain overall unaffected up to $T\\simeq150~MeV$ but, after this point, they start to diminish, considerably.
Deforming baryons into confining strings
Hartnoll, S A; Hartnoll, Sean A.; Portugues, Ruben
2004-01-01
We find explicit probe D3-brane solutions in the infrared of the Maldacena-Nunez background. The solutions describe deformed baryon vertices: q external quarks are separated in spacetime from the remaining N-q. As the separation is taken to infinity we recover known solutions describing infinite confining strings in ${\\mathcal{N}}=1$ gauge theory. We present results for the mass of finite confining strings as a function of length. We also find probe D2-brane solutions in a confining type IIA geometry, the reduction of a G_2 holonomy M theory background. The interpretation of these solutions as deformed baryons/confining strings is not as straightforward.
Tian, Hui; Wang, Tongjiang; Ofman, Leon; De Pontieu, Bart; Innes, Davina E; Peter, Hardi
2012-01-01
Using data obtained by the EUV Imaging Spectrometer (EIS) onboard Hinode, we have per- formed a survey of obvious and persistent (without significant damping) Doppler shift oscillations in the corona. We have found mainly two types of oscillations from February to April in 2007. One type is found at loop footpoint regions, with a dominant period around 10 minutes. They are characterized by coherent behavior of all line parameters (line intensity, Doppler shift, line width and profile asymmetry), apparent blue shift and blueward asymmetry throughout almost the en- tire duration. Such oscillations are likely to be signatures of quasi-periodic upflows (small-scale jets, or coronal counterpart of type-II spicules), which may play an important role in the supply of mass and energy to the hot corona. The other type of oscillation is usually associated with the upper part of loops. They are most clearly seen in the Doppler shift of coronal lines with forma- tion temperatures between one and two million degrees. The ...
Predictions for Excited Strange Baryons
Energy Technology Data Exchange (ETDEWEB)
Fernando, Ishara P.; Goity, Jose L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2016-04-01
An assessment is made of predictions for excited hyperon masses which follow from flavor symmetry and consistency with a 1/N c expansion of QCD. Such predictions are based on presently established baryonic resonances. Low lying hyperon resonances which do not seem to fit into the proposed scheme are discussed.
Algebraic model of baryon resonances
Bijker, R
1997-01-01
We discuss recent calculations of electromagnetic form factors and strong decay widths of nucleon and delta resonances. The calculations are done in a collective constituent model of the nucleon, in which the baryons are interpreted as rotations and vibrations of an oblate top.
Bijker, R; Leviatan, A
1997-01-01
We study strong decays of nonstrange baryons by making use of the algebraic approach to hadron structure. Within this framework we derive closed expressions for decay widths in an elementary-meson emission model and use these to analyze the experimental data for $N^* \\rightarrow N + \\pi$, $N^* + \\pi$, $\\Delta^* \\rightarrow \\Delta + \\pi$ and $\\Delta^* \\rightarrow \\Delta +
Baryon Number Current in Chiral Soliton Model
Institute of Scientific and Technical Information of China (English)
LiXiguo
2003-01-01
Last year two exotic and narrow baryons, θ+(1540) and Ξ3/2--(1862), which are pentaquark states have been reported by several group. Their minimal quark content are uudds and ddssu, respectively. The θ+(1540) baryon was observed in few independent experiments. Its hypercharge, Y=2. The exotic baryon is an isosinglet. The Ξ3/2--(1862) baryon was also observed in the Ξ-π- invariant mass spectrum in proton-proton scattering at the CERN SPS . The search of exotic baryons was motivated by the flavor SU(3) extension of
Energy Technology Data Exchange (ETDEWEB)
Hoeye, Gudrun Kristine
1999-07-01
We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l (>{sub )} 4) f-modes we were also able to derive a formula that determines II{sub l+1} from II{sub l} and II{sub l-1} to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n{sub c}, while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)
SPIDERS: the spectroscopic follow-up of X-ray selected clusters of galaxies in SDSS-IV
Clerc, N.; Merloni, A.; Zhang, Y.-Y.; Finoguenov, A.; Dwelly, T.; Nandra, K.; Collins, C.; Dawson, K.; Kneib, J.-P.; Rozo, E.; Rykoff, E.; Sadibekova, T.; Brownstein, J.; Lin, Y.-T.; Ridl, J.; Salvato, M.; Schwope, A.; Steinmetz, M.; Seo, H.-J.; Tinker, J.
2016-12-01
SPIDERS (The SPectroscopic IDentification of eROSITA Sources) is a programme dedicated to the homogeneous and complete spectroscopic follow-up of X-ray active galactic nuclei and galaxy clusters over a large area (˜7500 deg2) of the extragalactic sky. SPIDERS is part of the Sloan Digital Sky Survey (SDSS)-IV project, together with the Extended Baryon Oscillation Spectroscopic Survey and the Time-Domain Spectroscopic Survey. This paper describes the largest project within SPIDERS before the launch of eROSITA: an optical spectroscopic survey of X-ray-selected, massive (˜1014-1015 M⊙) galaxy clusters discovered in ROSAT and XMM-Newton imaging. The immediate aim is to determine precise (Δz ˜ 0.001) redshifts for 4000-5000 of these systems out to z ˜ 0.6. The scientific goal of the program is precision cosmology, using clusters as probes of large-scale structure in the expanding Universe. We present the cluster samples, target selection algorithms and observation strategies. We demonstrate the efficiency of selecting targets using a combination of SDSS imaging data, a robust red-sequence finder and a dedicated prioritization scheme. We describe a set of algorithms and work-flow developed to collate spectra and assign cluster membership, and to deliver catalogues of spectroscopically confirmed clusters. We discuss the relevance of line-of-sight velocity dispersion estimators for the richer systems. We illustrate our techniques by constructing a catalogue of 230 spectroscopically validated clusters (0.031 applications of the SPIDERS sample: the study of the X-ray luminosity-velocity dispersion (LX-σ) relation and the building of stacked phase-space diagrams.
SPIDERS: the spectroscopic follow-up of X-ray selected clusters of galaxies in SDSS-IV
Clerc, N.; Merloni, A.; Zhang, Y.-Y.; Finoguenov, A.; Dwelly, T.; Nandra, K.; Collins, C.; Dawson, K.; Kneib, J.-P.; Rozo, E.; Rykoff, E.; Sadibekova, T.; Brownstein, J.; Lin, Y.-T.; Ridl, J.; Salvato, M.; Schwope, A.; Steinmetz, M.; Seo, H.-J.; Tinker, J.
2016-09-01
SPIDERS (The SPectroscopic IDentification of eROSITA Sources) is a program dedicated to the homogeneous and complete spectroscopic follow-up of X-ray AGN and galaxy clusters over a large area (˜7500 deg2) of the extragalactic sky. SPIDERS is part of the SDSS-IV project, together with the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) and the Time-Domain Spectroscopic Survey (TDSS). This paper describes the largest project within SPIDERS before the launch of eROSITA: an optical spectroscopic survey of X-ray selected, massive (˜1014 to 1015~M⊙) galaxy clusters discovered in ROSAT and XMM-Newton imaging. The immediate aim is to determine precise (Δz ˜ 0.001) redshifts for 4,000-5,000 of these systems out to z ˜ 0.6. The scientific goal of the program is precision cosmology, using clusters as probes of large-scale structure in the expanding Universe. We present the cluster samples, target selection algorithms and observation strategies. We demonstrate the efficiency of selecting targets using a combination of SDSS imaging data, a robust red-sequence finder and a dedicated prioritization scheme. We describe a set of algorithms and work-flow developed to collate spectra and assign cluster membership, and to deliver catalogues of spectroscopically confirmed clusters. We discuss the relevance of line-of-sight velocity dispersion estimators for the richer systems. We illustrate our techniques by constructing a catalogue of 230 spectroscopically validated clusters (0.031 < z < 0.658), found in pilot observations. We discuss two potential science applications of the SPIDERS sample: the study of the X-ray luminosity-velocity dispersion (LX - σ) relation and the building of stacked phase-space diagrams.
Heavy Baryon Production and Decay
Dunietz, Isard
1998-01-01
The branching ratio B(Lambda_c -> p K- pi+) normalizes the production and decay of charmed and bottom baryons. At present, this crucial branching ratio is extracted dominantly from B.bar -> baryons analyses. This note questions several of the underlying assumptions and predicts sizable B.bar -> D(*) N N'.bar X transitions, which were traditionally neglected. It predicts B(Lambda_c -> p K- pi+) to be significantly larger (0.07 +/- 0.02) than the world average. Some consequences are briefly mentioned. Several techniques to measure B(Lambda_c -> p K- pi+) are outlined with existing or soon available data samples. By equating two recent CLEO results, an appendix obtains B(D0 -> K- pi+)= 0.035 +/- 0.002, which is somewhat smaller than the current world average.
Mathur, Smita; Williams, Rik J
2007-01-01
We review our attempts to discover lost baryons at low redshift with ``X-ray forest'' of absorption lines from the warm-hot intergalactic medium. We discuss the best evidence to date along the Mrk 421 sightline. We then discuss the missing baryons in the Local Group and the significance of the z=0 absorption systems in X-ray spectra. We argue that the debate over the Galactic vs. extragalactic origin of the z=0 systems is premature as these systems likely contain both components. Observations with next generation X-ray missions such as Constellation-X and XEUS will be crucial to map out the warm-hot intergalactic medium.
Algebraic model of baryon structure
Bijker, R
2000-01-01
We discuss properties of baryon resonances belonging to the Nucleon, Delta, Sigma, Lambda, Xi and Omega families in a collective string-like model for the nucleon, in which the radial excitations are interpreted as rotations and vibrations of the string configuration. We find good overall agreement with the available data. The main discrepancies are found for low lying S-wave states, in particular N(1535), N(1650), Sigma(1750), Lambda*(1405), Lambda(1670) and Lambda(1800).
Transport coefficients of heavy baryons
Tolos, Laura; Torres-Rincon, Juan M.; Das, Santosh K.
2016-08-01
We compute the transport coefficients (drag and momentum diffusion) of the low-lying heavy baryons Λc and Λb in a medium of light mesons formed at the later stages of high-energy heavy-ion collisions. We employ the Fokker-Planck approach to obtain the transport coefficients from unitarized baryon-meson interactions based on effective field theories that respect chiral and heavy-quark symmetries. We provide the transport coefficients as a function of temperature and heavy-baryon momentum, and analyze the applicability of certain nonrelativistic estimates. Moreover we compare our outcome for the spatial diffusion coefficient to the one coming from the solution of the Boltzmann-Uehling-Uhlenbeck transport equation, and we find a very good agreement between both calculations. The transport coefficients for Λc and Λb in a thermal bath will be used in a subsequent publication as input in a Langevin evolution code for the generation and propagation of heavy particles in heavy-ion collisions at LHC and RHIC energies.
Light Lepton Number Violating Sneutrinos and the Baryon Number of the Universe
Klapdor-Kleingrothaus, H V; Kuzmin, V A; Kolb, St.
2000-01-01
Recent results of neutrino oscillation experiments point to a nonvanishing neutrino mass. Neutrino mass models favour Majorana-type neutrinos. In such circumstances it is natural that the supersymmetric counterpart of the neutrino, the sneutrino, bears also lepton number violating properties. On the other hand, the fact that the universe exhibits an asymmetry in the baryon and antibaryon numbers poses constraints on the extent of lepton number violation in the light sneutrino sector. From the requirement that the Baryon Asymmetry of the Universe should not be washed out by sneutrino induced lepton number violating interactions we find that the mass splitting of the light sneutrino states is restricted to be very small.
Heavy Baryons and QCD Sum Rules
Yakovlev, O I
1996-01-01
We discuss an application of QCD sum rules to the heavy baryons $\\Lambda_Q$ and $\\Sigma_Q$. The predictions for the masses of heavy baryons, residues and Isgur-Wise function are presented. The new results on two loop anomalous dimensions of baryonic currents and QCD radiative corrections (two- and three- loop contributions) to the first two Wilson coefficients in OPE are explicitly presented.
Hadronic molecules in the heavy baryon spectrum
Entem, D. R.; Ortega, P. G.; Fernández, F.
2016-01-01
We study possible baryon molecules in the non-strange heavy baryon spectrum. We include configurations with a heavy-meson and a light baryon. We find several structures, in particular we can understand the Λc(2940) as a D*N molecule with JP = 3/2- quantum numbers. We also find D(*)Δ candidates for the recently discovered Xc(3250) resonance.
Gaztañaga, E; Castander, F; Crocce, M; Fosalba, P
2008-01-01
We present the 3-point function $\\xi_3$ and $Q_3=\\xi_3/\\xi_2^2$ for a spectroscopic volume limited sample of 40,000 luminous red galaxies (LRG) from the Sloan Digital Sky Survey DR6. We find a strong (S/N>6) detection of Q_3 on scales of 55-125 Mpc/h, with a well defined peak around 105 Mpc/h in all $\\xi_2$, $\\xi_3$ and Q_3, in excellent agreement with the predicted shape and location of the imprint of the baryon acoustic oscillations (BAO). We use very large simulations (from a cubic box of L=7680 Mpc/h) to asses and test the significance of our measurement. This detection demonstrates the non-linear growth of structure by gravitational instability between z=1000 and the present. Our measurements show the expected shape for Q_3 as a function of the triangular configuration. This provides a first direct measurement of the non-linear mode coupling coefficients of density and velocity fluctuations which, on these large scales, are independent of cosmic time, the amplitude of fluctuations or cosmological paramet...
Baryon Number Violation and String Topologies
Sjöstrand, Torbjörn
2003-01-01
In supersymmetric scenarios with broken R-parity, baryon number violating sparticle decays become possible. In order to search for such decays, a good understanding of expected event properties is essential. We here develop a complete framework that allows detailed studies. Special attention is given to the hadronization phase, wherein the baryon number violating vertex is associated with the appearance of a junction in the colour confinement field. This allows us to tell where to look for the extra (anti)baryon directly associated with the baryon number violating decay.
McKellar, A R W; Xu, Yunjie; Jäger, Wolfgang
2007-08-09
High-resolution spectra of HeN-OCS clusters with N up to 39 in the microwave region and up to 72 in the infrared region were observed with apparatus-limited line widths of about 15 kHz and 0.001 cm(-1), respectively. The cold (approximately 0.2 K) clusters were produced in pulsed supersonic jet expansions of very dilute OCS + He mixtures and probed using a microwave Fourier transform spectrometer or a tunable infrared diode laser spectrometer. Consistent analyses of the microwave and infrared data yield band origins for the carbonyl stretching vibration, together with rotational parameters for the ground and excited vibrational states. The rotational constant, B, passes through a minimum at N = 9 and then rises as the He atoms uncouple from the OCS rotational motion as a result of superfluid effects. There are broad unexpected oscillations in B, with maxima at N = 24 and 47 and minima at N = 36 and 62. The change in B upon vibrational excitation, which is negative for the OCS molecule, converges to positive values for N > 15. These results help to bridge the gap between individual molecules and bulk matter with atom-by-atom resolution over a significant range of cluster sizes.
Baryon Form Factors at Threshold
Energy Technology Data Exchange (ETDEWEB)
Baldini Ferroli, Rinaldo [Museo Storico della Fisica e Centro Studi e Ricerche ' E. Fermi' , Rome (Italy); INFN, Laboratori Nazionali di Frascati, Frascati (Italy); Pacetti, Simone [INFN and Dipartimento di Fisica, Universita di Perugia, Perugia (Italy)
2012-04-15
An extensive study of the e{sup +}e{sup -}{yields}pp{sup Macron }BABAR cross section data is presented. Two unexpected outcomes have been found: the modulus of the proton form factor is normalized to one at threshold, i.e.: |G{sup p}(4M{sub p}{sup 2})|=1, as a pointlike fermion, and the resummation factor in the Sommerfeld formula is not needed. Other e{sup +}e{sup -} {yields} baryon-antibaryon cross sections show a similar behavior near threshold.
Leptogenesis from Oscillations of Heavy Neutrinos with Large Mixing Angles
Drewes, Marco; Gueter, Dario; Klaric, Juraj
2016-01-01
The extension of the Standard Model by heavy right-handed neutrinos can simultaneously explain the observed neutrino masses via the seesaw mechanism and the baryon asymmetry of the Universe via leptogenesis. If the mass of the heavy neutrinos is below the electroweak scale, they may be found at LHCb, BELLE II, the proposed SHiP experiment or a future high-energy collider. In this mass range, the baryon asymmetry is generated via $CP$-violating oscillations of the heavy neutrinos during their production. We study the generation of the baryon asymmetry of the Universe in this scenario from first principles of non-equilibrium quantum field theory, including spectator processes and feedback effects. We eliminate several uncertainties from previous calculations and find that the baryon asymmetry of the Universe can be explained with larger heavy neutrino mixing angles, increasing the chance for an experimental discovery. For the limiting cases of fast and strongly overdamped oscillations of right-handed neutrinos,...
Baryon and lepton violation in astrophysics.
Kolb, E. W.
The cosmological and astrophysical significance of baryon and lepton number violating process is the subject of this paper. The possibility of baryon-number violating processes in the electroweak transition in the early universe is reviewed. The implications of lepton-number violation via Nambu-Goldstone bosons are discussed in detail.
Baryon spectroscopy and the omega minus
Energy Technology Data Exchange (ETDEWEB)
Samios, N.P.
1994-12-31
In this report, I will mainly discuss baryon resonances with emphasis on the discovery of the {Omega}{sup {minus}}. However, for completeness, I will also present some data on the meson resonances which together with the baryons led to the uncovering of the SU(3) symmetry of particles and ultimately to the concept of quarks.
Baryon number violation in future accelerators
Energy Technology Data Exchange (ETDEWEB)
Tracas, N.D.; Zoupanos, G.
1989-03-30
As a demonstration of the possibility to observe baryon number violation in the next generation of accelerators we present a semirealistic GUT in which proton decay is forbidden and the unification scale is at approx. = 10/sup 3-4/ TeV, leading therefore to observable baryon number violating processes.
Exactly solvable models of baryon structure
Bijker, R
1998-01-01
We present a qualitative analysis of the gross features of baryon spectroscopy (masses and form factors) in terms of various exactly solvable models. It is shown that a collective model, in which baryon resonances are interpreted as rotations and vibrations of an oblate symmetric top, provides a good starting point for a more detailed quantitative study.
Exactly solvable models of baryon structure
Energy Technology Data Exchange (ETDEWEB)
Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico. Apartado Postal 70-543, 04510 Mexico D.F. (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University. Jerusalem 91904, Israel (Israel)
1998-12-31
We present a qualitative analysis of the gross features of baryon spectroscopy (masses and form factors) in terms of various exactly solvable models. It is shown that a collective model, in which baryon resonances are interpreted as rotations and vibrations of an oblate symmetric top, provides a good starting point for a more detailed quantitative study. (Author)
(Hybrid) Baryons Quantum Numbers and Adiabatic Potentials
Page, P R
1999-01-01
We construct (hybrid) baryons in the flux-tube model of Isgur and Paton. In the limit of adiabatic quark motion, we build proper eigenstates of orbital angular momentum and indicate the flavour, spin, chirality and J^P of (hybrid) baryons. The adiabatic potential is calculated as a function of the quark positions.
Pathways to Rare Baryonic B Decays
Hou Wei Shu; Hou, Wei-Shu
2001-01-01
We point out new ways to search for charmless baryonic B decays: baryon pair production in association with $\\eta^\\prime$ is very likely as large as or even a bit larger than two body $K\\pi/\\pi\\pi$ modes. We extend our argument, in weaker form, to $B\\to \\gamma + X_s$ and $\\ell\
A rotating string model versus baryon spectra
Sonnenschein, Jacob
2014-01-01
We continue our program of describing hadrons as rotating strings with massive endpoints. In this paper we propose models of baryons and confront them with the baryon Regge trajectories. We show that these are best fitted by a model of a single string with a quark at one endpoint and a diquark at the other. This model is preferred over the Y-shaped string model with a quark at each endpoint. We show how the model follows from a stringy model of the holographic baryon which includes a baryonic vertex connected with $N_c$ strings to flavor probe branes. From fitting to baryonic data we find that there is no clear evidence for a non-zero baryonic vertex mass, but if there is such a mass it should be located at one of the string endpoints. The available baryon trajectories in the angular momentum plane $(J,M^2)$, involving light, strange, and charmed baryons, are rather well fitted when adding masses to the string endpoints, with a single universal slope $\\alp = 0.95$ GeV$^{-2}$. Most of the results for the quark...
Baryon form factors in chiral perturbation theory
Kubis, B; Kubis, Bastian; Meissner, Ulf-G.
2001-01-01
We analyze the electromagnetic form factors of the ground state baryon octet to fourth order in relativistic baryon chiral perturbation theory. Predictions for the \\Sigma^- charge radius and the \\Lambda-\\Sigma^0 transition moment are found to be in excellent agreement with the available experimental information. Furthermore, the convergence behavior of the hyperon charge radii is shown to be more than satisfactory.
Exploring the simplest purely baryonic decay processes
Geng, C Q; Rodrigues, Eduardo
2016-01-01
We propose to search for purely baryonic decay processes at the LHCb experiment. In particular, we concentrate on the decay $\\Lambda_b^0\\to p\\bar pn$, which is the simplest purely baryonic decay mode, with solely spin-1/2 baryons involved. We predict its decay branching ratio to be ${\\cal B}(\\Lambda_b^0\\to p\\bar pn)=(2.0^{+0.3}_{-0.2})\\times 10^{-6}$, which is sufficiently large to make the decay mode accessible to LHCb. Though not considered in general, purely baryonic decays could shed light on the puzzle of the baryon number asymmetry in the universe by means of a better understanding of the baryonic nature of our matter world. As such, they constitute a yet unexplored class of decay processes worth investigating. Our study can be extended to the purely baryonic decays of $\\Lambda_b^0\\to p\\bar p \\Lambda$, $\\Lambda_b^0\\to \\Lambda \\bar p\\Lambda$ and $\\Lambda_b^0\\to \\Lambda\\bar \\Lambda\\Lambda$, as well as other similar anti-triplet $b$-baryon decays, such as $\\Xi_b^{0,-}$.
Baryon symmetric big bang cosmology
Stecker, F. W.
1978-01-01
Both the quantum theory and Einsteins theory of special relativity lead to the supposition that matter and antimatter were produced in equal quantities during the big bang. It is noted that local matter/antimatter asymmetries may be reconciled with universal symmetry by assuming (1) a slight imbalance of matter over antimatter in the early universe, annihilation, and a subsequent remainder of matter; (2) localized regions of excess for one or the other type of matter as an initial condition; and (3) an extremely dense, high temperature state with zero net baryon number; i.e., matter/antimatter symmetry. Attention is given to the third assumption, which is the simplest and the most in keeping with current knowledge of the cosmos, especially as pertains the universality of 3 K background radiation. Mechanisms of galaxy formation are discussed, whereby matter and antimatter might have collided and annihilated each other, or have coexisted (and continue to coexist) at vast distances. It is pointed out that baryon symmetric big bang cosmology could probably be proved if an antinucleus could be detected in cosmic radiation.
The Dark Energy Spectroscopic Instrument (DESI) instrument mechanism control systems
Coker, Carl T.; Pappalardo, Daniel; Pogge, Richard; Martini, Paul; Derwent, Mark; O'Brien, Thomas P.; Honscheid, Klaus
2016-08-01
The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 40 million galaxies over 14,000 sq deg will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5,000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. We present the design details of the instrument mechanism control systems for the spectrographs. Each spectrograph has a stand-alone mechanism control box that operates the unit's four remotely-operated mechanisms (two shutters and two Hartmannn doors), and provides a suite of temperature and humidity sensors. Each control box is highly modular, and is operated by a dedicated on-board Linux computer to provide all of the control and monitoring functions. We describe our solution for integrating a number of network-connected devices within each unit spectrograph, and describe the basic software architecture.
Pion mean fields and heavy baryons
Yang, Ghil-Seok; Polyakov, Maxim V; Praszałowicz, Michał
2016-01-01
We show that the masses of the lowest-lying heavy baryons can be very well described in a pion mean-field approach. We consider a heavy baryon as a system consisting of the $N_c-1$ light quarks that induce the pion mean field, and a heavy quark as a static color source under the influence of this mean field. In this approach we derive a number of \\textit{model-independent} relations and calculate the heavy baryon masses using those of the lowest-lying light baryons as input. The results are in remarkable agreement with the experimental data. In addition, the mass of the $\\Omega_b^*$ baryon is predicted.
Strangeness in the baryon ground states
Semke, A
2012-01-01
We compute the strangeness content of the baryon ground states based on an analysis of recent lattice simulations of the BMW, PACS, LHPC and HSC groups for the pion-mass dependence of the baryon masses. Our results rely on the relativistic chiral Lagrangian and large-$N_c$ sum rule estimates of the counter terms relevant for the baryon masses at N$^3$LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. A simultaneous description of the lattice results of the BMW, LHPC, PACS and HSC groups is achieved. We predict the pion- and strangeness sigma terms and the pion-mass dependence of the octet and decuplet ground states at different strange quark masses.
Baryons and baryonic matter in the large Nc and heavy quark limits
Cohen, Thomas D; Ndousse, Kamal K
2011-01-01
This paper explores properties of baryons and finite density baryonic matter in an artificial world in which Nc, the number of colors, is large and the quarks of all species are degenerate and much larger than {\\Lambda}_QCD. It has long been known that in large Nc QCD, baryons composed entirely of heavy quarks are accurately described in the mean-field approximation. However, the detailed properties of baryons in the combined large Nc and heavy quark limits have not been fully explored. Here some basic properties of baryons are computed using a variational approach. At leading order in both the large Nc and heavy quark expansions the baryon mass is computed explicitly as is the baryon form factor. Baryonic matter, the analog of nuclear matter in this artificial world, should also be well described in the mean-field approximation. In the special case where all baryons have an identical spin flavor structure, it is shown that in the formal heavy quark and large Nc limit interactions between baryons are strictly...
Light baryons and their excitations
Eichmann, Gernot; Fischer, Christian S.; Sanchis-Alepuz, Hèlios
2016-11-01
We study ground states and excitations of light octet and decuplet baryons within the framework of Dyson-Schwinger and Faddeev equations. We improve upon similar approaches by explicitly taking into account the momentum-dependent dynamics of the quark-gluon interaction that leads to dynamical chiral symmetry breaking. We perform calculations in both the three-body Faddeev framework and the quark-diquark approximation in order to assess the impact of the latter on the spectrum. Our results indicate that both approaches agree well with each other. The resulting spectra furthermore agree one-to-one with experiment, provided well-known deficiencies of the rainbow-ladder approximation are compensated for. We also discuss the mass evolution of the Roper and the excited Δ with varying pion mass and analyze the internal structure in terms of their partial wave decompositions.
Diffuse baryonic matter beyond 2020
Markevitch, M; Nulsen, P; Rasia, E; Vikhlinin, A; Kravtsov, A; Forman, W; Brunetti, G; Sarazin, C; Elvis, M; Fabbiano, G; Hornschemeier, A; Brissenden, R
2009-01-01
The hot, diffuse gas that fills the largest overdense structures in the Universe -- clusters of galaxies and a web of giant filaments connecting them -- provides us with tools to address a wide array of fundamental astrophysical and cosmological questions via observations in the X-ray band. Clusters are sensitive cosmological probes. To utilize their full potential for precision cosmology in the following decades, we must precisely understand their physics -- from their cool cores stirred by jets produced by the central supermassive black hole (itself fed by inflow of intracluster gas), to their outskirts, where the infall of intergalactic medium (IGM) drives shocks and accelerates cosmic rays. Beyond the cluster confines lies the virtually unexplored warm IGM, believed to contain most of the baryonic matter in the present-day Universe. As a depository of all the matter ever ejected from galaxies, it carries unique information on the history of energy and metal production in the Universe. Currently planned ma...
Holography, charge and baryon asymmetry
Mongan, T R
2009-01-01
The holographic principle indicates the finite number of bits of information available on the particle horizon describes all physics within the horizon. Linking information on the horizon with Standard Model particles requires a holographic model describing constituents (preons) of Standard Model particles in terms of bits of information on the horizon. Standard Model particles have charges 0, 1/3, 2/3 or 1 in units of the electron charge e, so bits in a preon model must be identified with fractional charge. Energy must be transferred to change the state of a bit, and labeling the low energy state of a bit e/3n and the high energy state -e/3n amounts to defining electric charge. Any such charged preon model will produce more protons than anti-protons at the time of baryogenesis and require baryon asymmetry. It will also produce more positrons than electrons, as suggested by astrophysical measurements.
Baryon-Baryon Interactions ---Nijmegen Extended-Soft-Core Models---
Rijken, T. A.; Nagels, M. M.; Yamamoto, Y.
We review the Nijmegen extended-soft-core (ESC) models for the baryon-baryon (BB) interactions of the SU(3) flavor-octet of baryons (N, Lambda, Sigma, and Xi). The interactions are basically studied from the meson-exchange point of view, in the spirit of the Yukawa-approach to the nuclear force problem [H. Yukawa, ``On the interaction of Elementary Particles I'', Proceedings of the Physico-Mathematical Society of Japan 17 (1935), 48], using generalized soft-core Yukawa-functions. These interactions are supplemented with (i) multiple-gluon-exchange, and (ii) structural effects due to the quark-core of the baryons. We present in some detail the most recent extended-soft-core model, henceforth referred to as ESC08, which is the most complete, sophisticated, and successful interaction-model. Furthermore, we discuss briefly its predecessor the ESC04-model [Th. A. Rijken and Y. Yamamoto, Phys. Rev. C 73 (2006), 044007; Th. A. Rijken and Y. Yamamoto, Ph ys. Rev. C 73 (2006), 044008; Th. A. Rijken and Y. Yamamoto, nucl-th/0608074]. For the soft-core one-boson-exchange (OBE) models we refer to the literature [Th. A. Rijken, in Proceedings of the International Conference on Few-Body Problems in Nuclear and Particle Physics, Quebec, 1974, ed. R. J. Slobodrian, B. Cuec and R. Ramavataram (Presses Universitè Laval, Quebec, 1975), p. 136; Th. A. Rijken, Ph. D. thesis, University of Nijmegen, 1975; M. M. Nagels, Th. A. Rijken and J. J. de Swart, Phys. Rev. D 17 (1978), 768; P. M. M. Maessen, Th. A. Rijken and J. J. de Swart, Phys. Rev. C 40 (1989), 2226; Th. A. Rijken, V. G. J. Stoks and Y. Yamamoto, Phys. Rev. C 59 (1999), 21; V. G. J. Stoks and Th. A. Rijken, Phys. Rev. C 59 (1999), 3009]. All ingredients of these latter models are also part of ESC08, and so a description of ESC08 comprises all models so far in principle. The extended-soft-core (ESC) interactions consist of local- and non-local-potentials due to (i) one-boson-exchanges (OBE), which are the members of nonets of
Holographic heavy ion collisions with baryon charge
Casalderrey-Solana, Jorge; van der Schee, Wilke; Triana, Miquel
2016-01-01
We numerically simulate collisions of charged shockwaves in Einstein-Maxwell theory in anti-de Sitter space as a toy model of heavy ion collisions with non-zero baryon charge. The stress tensor and the baryon current become well described by charged hydrodynamics at roughly the same time. The effect of the charge density on generic observables is typically no larger than 15\\%. %The rapidity profile of the charge is wider than the profile of the local energy density. We find significant stopping of the baryon charge and compare our results with those in heavy ion collision experiments.
More about the light baryon spectrum
Eichmann, Gernot
2016-01-01
We discuss the light baryon spectrum obtained from a recent quark-diquark calculation, implementing non-pointlike diquarks that are self-consistently calculated from their Bethe-Salpeter equations. We examine the orbital angular momentum content in the baryons' rest frame and highlight the fact that baryons carry all possible values of L compatible with their spin, without the restriction P=(-1)^L which is only valid nonrelativistically. We furthermore investigate the meaning of complex conjugate eigenvalues of Bethe-Salpeter equations, their possible connection with 'anomalous' states, and we propose a method to eliminate them from the spectrum.
More About the Light Baryon Spectrum
Eichmann, Gernot
2017-03-01
We discuss the light baryon spectrum obtained from a recent quark-diquark calculation, implementing non-pointlike diquarks that are self-consistently calculated from their Bethe-Salpeter equations. We examine the orbital angular momentum content in the baryons' rest frame and highlight the fact that baryons carry all possible values of L compatible with their spin, without the restriction P=(-1)^L which is only valid nonrelativistically. We furthermore investigate the meaning of complex conjugate eigenvalues of Bethe-Salpeter equations, their possible connection with `anomalous' states, and we propose a method to eliminate them from the spectrum.
Pire, Bernard; Szymanowski, Lech
2010-01-01
We construct a spectral representation for the transition distribution amplitudes (TDAs), i.e. matrix elements of three quark correlators which arise e.g. in the description of baryon to meson and baryon to photon transitions within the factorization approach to hard exclusive reactions. We generalize for these quantities the notion of double distributions introduced in the context of generalized parton distributions. We propose the generalization of A.Radyushkin's factorized Ansatz for the case of baryon to meson and baryon to photon TDAs. Our construction opens the way to modeling of baryon to meson and baryon to photon TDAs in their complete domain of definition and quantitative estimates of cross-sections for various hard exclusive reactions.
Landau Damping of Baryon Structure Formation in the Post Reionization Epoch
Chang, Feng-Yin
2010-01-01
It has been suggested by Chen and Lai that the proper description of the large scale structure formation of the universe in the post-reionization era, which is conventionally characterized via gas hydrodynamics, should include the plasma collective effects in the formulation. Specifically, it is the combined pressure from the baryon thermal motions and the residual long-range electrostatic potentials resulted from the imperfect Debye shielding, that fights against the gravitational collapse. As a result, at small-scales the baryons would oscillate at the ion-acoustic, instead of the conventional neutral acoustic, frequency. In this paper we extend and improve the Chen-Lai formulation with the attention to the Landau damping of the ion-acoustic oscillations. Since T_e \\sim T_i in the post-reionization era, the ion acoustic oscillations would inevitably suffer the Landau damping which severely suppresses the baryon density spectrum in the regimes of intermediate and high wavenumber k. To describe this Landau-da...
Masses and magnetic moments of ground-state baryons in covariant baryon chiral perturbation theory
Geng, L S; Alvarez-Ruso, L; Vicente-Vacas, M J
2012-01-01
We report on some recent developments in our understanding of the light-quark mass dependence and the SU(3) flavor symmetry breaking corrections to the magnetic moments of the ground-state baryons in a covariant formulation of baryon chiral perturbation theory, the so-called EOMS formulation. We show that this covariant ChPT exhibits some promising features compared to its heavy-baryon and infrared counterparts.
Semileptonic Decays of Heavy Omega Baryons in a Quark Model
Pervin, M; Capstick, S; Pervin, Muslema
2006-01-01
The semileptonic decays of $\\Omega_c$ and $\\Omega_b$ are treated in the framework of a constituent quark model developed in a previous paper on the semileptonic decays of heavy $\\Lambda$ baryons. Analytic results for the form factors for the decays to ground states and a number of excited states are evaluated. For $\\Omega_b$ to $\\Omega_c$ the form factors obtained are shown to satisfy the relations predicted at leading order in the heavy-quark effective theory at the non-recoil point. A modified fit of nonrelativistic and semirelativistic Hamiltonians generates configuration-mixed baryon wave functions from the known masses and the measured $\\lcle$ rate, with wave functions expanded in both harmonic oscillator and Sturmian bases. Decay rates of $\\ob$ to pairs of ground and excited $\\omc$ states related by heavy-quark symmetry calculated using these configuration-mixed wave functions are in the ratios expected from heavy-quark effective theory, to a good approximation. Our predictions for the semileptonic elas...
Suppression of Baryon Diffusion and Transport in a Baryon Rich Strongly Coupled Quark-Gluon Plasma.
Rougemont, Romulo; Noronha, Jorge; Noronha-Hostler, Jacquelyn
2015-11-13
Five dimensional black hole solutions that describe the QCD crossover transition seen in (2+1)-flavor lattice QCD calculations at zero and nonzero baryon densities are used to obtain predictions for the baryon susceptibility, baryon conductivity, baryon diffusion constant, and thermal conductivity of the strongly coupled quark-gluon plasma in the range of temperatures 130 MeV≤T≤300 MeV and baryon chemical potentials 0≤μ(B)≤400 MeV. Diffusive transport is predicted to be suppressed in this region of the QCD phase diagram, which is consistent with the existence of a critical end point at larger baryon densities. We also calculate the fourth-order baryon susceptibility at zero baryon chemical potential and find quantitative agreement with recent lattice results. The baryon transport coefficients computed in this Letter can be readily implemented in state-of-the-art hydrodynamic codes used to investigate the dense QGP currently produced at RHIC's low energy beam scan.
Baryon asymmetry from primordial black holes
Hamada, Yuta
2016-01-01
We propose a new scenario of the baryogenesis from primordial black holes (PBH). Assuming presence of a microscopic baryon (or lepton) number violation and a CP violating operator such as $\\partial_\\alpha F(\\mathcal{R_{....}} ) J^\\alpha$ where $F(\\mathcal{R_{....}})$ is a scalar function of the Riemann tensor, time evolution of an evaporating black hole generates baryonic (leptonic) chemical potential at the horizon; consequently PBH enumerates asymmetric Hawking radiation between baryons (leptons) and anti-baryons (leptons). Though the operator is higher dimensional and largely suppressed by a high mass scale $M_*$, we show that sufficient amount of asymmetry can be generated for wide range of parameters of the PBH mass $M_{\\rm PBH}$, its abundance $\\Omega_{\\rm PBH}$, and the scale $M_*$.
Baryonic torii: Toroidal baryons in a generalized Skyrme model
Gudnason, Sven Bjarke; Nitta, Muneto
2015-02-01
We study a Skyrme-type model with a potential term motivated by Bose-Einstein condensates (BECs), which we call the BEC Skyrme model. We consider two flavors of the model: the first is the Skyrme model, and the second has a sixth-order derivative term instead of the Skyrme term, both with the added BEC-motivated potential. The model contains toroidally shaped Skyrmions, and they are characterized by two integers P and Q , representing the winding numbers of two complex scalar fields along the toroidal and poloidal cycles of the torus, respectively. The baryon number is B =P Q . We find stable Skyrmion solutions for P =1 ,2 ,3 ,4 ,5 with Q =1 , while for P =6 and Q =1 , it is only metastable. We further find that configurations with higher Q >1 are all unstable and split into Q configurations with Q =1 . Finally we discover a phase transition, possibly of first order, in the mass parameter of the potential under study.
Heavy Flavor Baryons at the Tevatron
Energy Technology Data Exchange (ETDEWEB)
Kuhr, Thomas
2011-09-01
The Tevatron experiments CDF and D0 have filled many empty spots in the spectrum of heavy baryons over the last few years. The most recent results are described in this article: The first direct observation of the {Xi}{sub b}{sup 0}, improved measurements of {Sigma}{sub b} properties, a new measurement of the {Lambda}{sub b} {yields} J/{psi}{Lambda} branching ratio, and a high-statistics study of charm baryons.
Discriminating Majorana Neutrino Textures in the light of Baryon Asymmetry
Borah, Manikanta; Das, Mrinal Kumar
2015-01-01
We study all possible texture zeros in the Majorana neutrino mass matrix which are allowed from neutrino oscillation as well as cosmology data when the charged lepton mass matrix is assumed to take the diagonal form. Considering two different possible values of the lightest neutrino mass giving rise to quasi-degenerate and hierarchical light neutrino mass spectrum respectively, we write down the Majorana CP phases as a function of the Dirac CP phase using the constraints coming from vanishing or equality of elements in a particular texture zero mass matrix. We constrain texture zero mass matrices from the requirement of producing correct baryon asymmetry through the mechanism of leptogenesis. Adopting a type I seesaw framework, we consider the CP violating out of equilibrium decay of the lightest right handed neutrino as the source of lepton asymmetry. Apart from discriminating between the texture zero mass matrices and light neutrino mass hierarchy, we also constrain the Dirac CP phase so that the observed b...
The baryon spectrum and the hypercentral Constituent Quark Model
Giannini, M M
2015-01-01
The description of the baryon spectrum is performed using the hypercentral Consituent Quark Model (hCQM), mainly in comparison with the harmonic oscillator (h.o.). Recentlly many new states, at various levels of confidence have been observed, leading to a softening of the missing resonance problem in the case of positive parity states. However, the number of negative states is higher that predicted by the commonly used h.o. scheme and therefore one is forced to take into account also the higher energy shells, which contain an overall number of states much greater than the observed one. It is shown that, thanks to the peculiar level scheme of the hCQM, the recently observed negative parity states can be considered as belonging to the lower shells, keeping the missing resonance problem within more acceptable limits.
The baryon content of the Cosmic Web
Eckert, Dominique; Jauzac, Mathilde; Shan, HuanYuan; Kneib, Jean-Paul; Erben, Thomas; Israel, Holger; Jullo, Eric; Klein, Matthias; Massey, Richard; Richard, Johan; Tchernin, Céline
2015-01-01
Big-Bang nucleosynthesis indicates that baryons account for 5% of the Universe’s total energy content[1]. In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two[2,3]. Cosmological simulations indicate that the missing baryons have not yet condensed into virialised halos, but reside throughout the filaments of the cosmic web: a low-density plasma at temperature 105–107 K known as the warm-hot intergalactic medium (WHIM)[3,4,5,6]. There have been previous claims of the detection of warm baryons along the line of sight to distant blazars[7,8,9,10] and hot gas between interacting clusters[11,12,13,14]. These observations were however unable to trace the large-scale filamentary structure, or to estimate the total amount of warm baryons in a representative volume of the Universe. Here we report X-ray observations of filamentary structures of ten-million-degree gas associated with the galaxy cluster Abell 2744. Previous observations of this cluster[15] were unable to resolve and remove coincidental X-ray point sources. After subtracting these, we reveal hot gas structures that are coherent over 8 Mpc scales. The filaments coincide with over-densities of galaxies and dark matter, with 5-10% of their mass in baryonic gas. This gas has been heated up by the cluster's gravitational pull and is now feeding its core. PMID:26632589
Spin-flavor composition of excited baryons
Fernando, Ishara; Goity, Jose
2015-10-01
The excited baryon masses are analyzed in the framework of the 1 /Nc expansion using the available physical masses and also the masses obtained in lattice QCD for different quark masses. The baryon states are organized into irreducible representations of SU (6) × O (3) , where the [ 56 ,lP =0+ ] ground state and excited baryons, and the [ 56 ,2+ ] and [ 70 ,1- ] excited states are analyzed. The analyses are carried out to O 1 /Nc and first order in the quark masses. The issue of state identifications is discussed. Numerous parameter independent mass relations result at those orders, among them the well known Gell-Mann-Okubo and Equal Spacing relations, as well as additional relations involving baryons with different spins. It is observed that such relations are satisfied at the expected level of precision. Predictions for physically unknown states for each multiplet are obtained. From the quark-mass dependence of the coefficients in the baryon mass formulas an increasingly simpler picture of the spin-flavor composition of the baryons is observed with increasing pion mass (equivalently, increasing mu , d masses), as measured by the number of significant mass operators. This work was supported in part by DOE Contract No. DE-AC05-06OR23177 under which JSA operates the Thomas Jefferson National Accelerator Facility (J. L. G.), and by the NSF (USA) through Grant PHY-0855789 and PHY-1307413 (I. P. F and J. L. G).
Semileptonic Decays of Heavy Omega Baryons in a Quark Model
Energy Technology Data Exchange (ETDEWEB)
Muslema Pervin; Winston Roberts; Simon Capstick
2006-03-24
The semileptonic decays of {Omega}{sub c} and {Omega}{sub b} are treated in the framework of a constituent quark model developed in a previous paper on the semileptonic decays of heavy {Lambda} baryons. Analytic results for the form factors for the decays to ground states and a number of excited states are evaluated. For {Omega}{sub b} to {Omega}{sub c} the form factors obtained are shown to satisfy the relations predicted at leading order in the heavy-quark effective theory at the non-recoil point. A modified fit of nonrelativistic and semirelativistic Hamiltonians generates configuration-mixed baryon wave functions from the known masses and the measured {Lambda}{sub c}{sup +} {yields} {Lambda}e{sup +}{nu} rate, with wave functions expanded in both harmonic oscillator and Sturmian bases. Decay rates of {Omega}{sub b} to pairs of ground and excited {Omega}{sub c} states related by heavy-quark symmetry calculated using these configuration-mixed wave functions are in the ratios expected from heavy-quark effective theory, to a good approximation. Our predictions for the semileptonic elastic branching fraction of {Omega}{sub Q} vary minimally within the models we use. We obtain an average value of (84 {+-} 2%) for the fraction of {Omega}{sub c} {yields} {Xi}{sup (*)} decays to ground states, and 91% for the fraction of {Omega}{sub c} {yields} {Omega}{sup (*)} decays to the ground state {Omega}. The elastic fraction of {Omega}{sub b} {yields} {Omega}{sub c} ranges from about 50% calculated with the two harmonic-oscillator models, to about 67% calculated with the two Sturmian models.
Semileptonic Decays of Heavy Lambda Baryons in a Quark Model
Energy Technology Data Exchange (ETDEWEB)
Winston Roberts; Muslema Pervin; Simon Capstick
2005-03-01
The semileptonic decays of {Lambda}{sub c} and {Lambda}{sub b} are treated in the framework of a constituent quark model. Both nonrelativistic and semirelativistic Hamiltonians are used to obtain the baryon wave functions from a fit to the spectra, and the wave functions are expanded in both the harmonic oscillator and Sturmian bases. The latter basis leads to form factors in which the kinematic dependence on q{sup 2} is in the form of multipoles, and the resulting form factors fall faster as a function of q{sup 2} in the available kinematic ranges. As a result, decay rates obtained in the two models using the Sturmian basis are significantly smaller than those obtained using the harmonic oscillator basis. In the case of the {Lambda}{sub c}, decay rates calculated using the Sturmian basis are closer to the experimentally reported rates. However, we find a semileptonic branching fraction for the {Lambda}{sub c} to decay to excited {Lambda}* states of 11% to 19%, in contradiction with what is assumed in available experimental analyses. Our prediction for the {Lambda}{sub b} semileptonic decays is that decays to the ground state {Lambda}{sub c} provide a little less than 70% of the total semileptonic decay rate. For the decays {Lambda}{sub b} {yields} {Lambda}{sub c}, the analytic form factors we obtain satisfy the relations expected from heavy-quark effective theory at the non-recoil point, at leading and next-to-leading orders in the heavy-quark expansion. In addition, some features of the heavy-quark limit are shown to naturally persist as the mass of the heavy quark in the daughter baryon is decreased.
Disentanglement of Electromagnetic Baryon Properties
Sadasivan, Daniel; Doring, Michael
2017-01-01
Through recent advances in experimental techniques, the precise extraction of the spectrum of baryonic resonances and their properties becomes possible. Helicity couplings at the resonance pole are fundamental parameters describing the electromagnetic properties of resonances and enabling the comparison of theoretical models with data. We have extracted them from experiments carried out at Jefferson Lab and other facilities using a multipole analysis within the Julich-Bonn framework. Special attention has been paid to the uncertainties and correlations of helicity couplings. Using the world data on the reaction γp -> ηp , we have calculated, for the first time, the covariance matrix. Our results are useful in several ways. They quantify uncertainties but also correlations of helicity couplings. Second, they can tell us quantitatively how useful a given polarization measurement is. Third, they can tell us how the measurement of a new observable would constrain and disentangle the resonance properties which could be helpful in the design of new experiments. Finally, on the subject of the missing resonance problem, model selection techniques and statistical tests allow us to quantify the significance of whether a resonance exists. Supported by NSF CAREER Grant No. PHY-1452055, NSF PIF Grant No. 1415459, by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177, and by Research Center Julich through the HPC grant jikp07.
Search for doubly charmed baryons and study of charmed strange baryons at Belle
Energy Technology Data Exchange (ETDEWEB)
Kato, Y.; Iijima, T.; Adachi, I.; Aihara, H.; Asner, D. M.; Aushev, T.; Bakich, A. M.; Bala, A.; Ban, Y.; Bhardwaj, V.; Bhuyan, B.; Bobrov, A.; Bonvicini, G.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, K.; Chobanova, V.; Choi, Y.; Cinabro, D.; Dalseno, J.; Danilov, M.; Doležal, Z.; Drásal, Z.; Drutskoy, A.; Dutta, D.; Dutta, K.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Gaur, V.; Gabyshev, N.; Ganguly, S.; Garmash, A.; Gillard, R.; Goh, Y. M.; Golob, B.; Haba, J.; Hayasaka, K.; Hayashii, H.; He, X. H.; Horii, Y.; Hoshi, Y.; Hou, W. -S.; Hsiung, Y. B.; Inami, K.; Ishikawa, A.; Iwasaki, Y.; Iwashita, T.; Jaegle, I.; Julius, T.; Kang, J. H.; Kato, E.; Kawasaki, T.; Kiesling, C.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, J. H.; Kim, M. J.; Kim, Y. J.; Klucar, J.; Ko, B. R.; Kodyš, P.; Korpar, S.; Krokovny, P.; Kuhr, T.; Kuzmin, A.; Kwon, Y. -J.; Lee, S. -H.; Li, J.; Li, Y.; Li Gioi, L.; Libby, J.; Liu, Y.; Liventsev, D.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Moll, A.; Muramatsu, N.; Mussa, R.; Nagasaka, Y.; Nakano, E.; Nakao, M.; Nakazawa, H.; Nayak, M.; Nedelkovska, E.; Ng, C.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Nitoh, O.; Ogawa, S.; Okuno, S.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Park, H.; Park, H. K.; Pedlar, T. K.; Peng, T.; Pestotnik, R.; Petrič, M.; Piilonen, L. E.; Ritter, M.; Röhrken, M.; Rostomyan, A.; Sahoo, H.; Saito, T.; Sakai, Y.; Sandilya, S.; Santelj, L.; Sanuki, T.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Semmler, D.; Senyo, K.; Seon, O.; Shapkin, M.; Shen, C. P.; Shibata, T. -A.; Shiu, J. -G.; Shwartz, B.; Sibidanov, A.; Sohn, Y. -S.; Sokolov, A.; Solovieva, E.; Stanič, S.; Starič, M.; Steder, M.; Sumihama, M.; Sumiyoshi, T.; Tamponi, U.; Tanida, K.; Tatishvili, G.; Teramoto, Y.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Van Hulse, C.; Vanhoefer, P.; Varner, G.; Vinokurova, A.; Vorobyev, V.; Wagner, M. N.; Wang, C. H.; Wang, M. -Z.; Wang, P.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yamashita, Y.; Yashchenko, S.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.
2014-03-17
We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider.
Gaztanaga, Enrique; Hui, Lam
2008-01-01
This is the 4th paper in a series where we study the clustering of LRG galaxies in the latest spectroscopic SDSS data release, DR6, which has 75000 LRG galaxies sampling 1.1 (Gpc/h)^3 to z=0.47. Here we study the 2-point correlation function, separated in perpendicular (sigma) and line-of-sight (pi) directions. We find a significant detection of a peak at r=110 Mpc/h, which shows as a circular ring in the sigma-pi plane. There is also a significant detection of the peak along the line-of-sight (LOS) direction both in sub-samples at low, z=0.15-30, and high redshifts, z=0.40-0.47. The overall shape and location of the peak is consistent with baryon acoustic oscillations (BAO). The amplitude in the line-of-sight direction, however, is larger than conventional expectations. We argue this is due to magnification bias. Because the data is shot noise dominated, a lensing boost in signal translates into a boost in S/N. We take advantage of this high S/N to produce, for the first time, a direct measurement of the Hub...
Baryon-baryon bound states in a (2+1)-dimensional lattice QCD model
Faria da Veiga, Paulo A.; O'Carroll, Michael; Schor, Ricardo
2003-08-01
We consider bound states of two baryons (antibaryons) in lattice QCD in a Euclidean formulation. For simplicity, we analyze an SU(3) theory with a single flavor in 2+1 dimensions and two-dimensional Dirac matrices. For a small hopping parameter 0<κ≪1 and large glueball mass, we recently showed the existence of a (anti)baryonlike particle, with an asymptotic mass of the order of -3 ln κ and with an isolated dispersion curve, i.e., an upper gap property persisting up to near the meson-baryon threshold, which is of order -5 ln κ. Here, we show that there is no baryon-baryon (or antibaryon-antibaryon) bound state solution to the Bethe-Salpeter equation up to the two-baryon threshold, which is approximately -6 ln κ.
Energy Technology Data Exchange (ETDEWEB)
Ahn, Christopher P.; Anderton, Timothy [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Alexandroff, Rachael [Center for Astrophysical Sciences, Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Allende Prieto, Carlos [Instituto de Astrofísica de Canarias (IAC), C/Vía Láctea, s/n, E-38200, La Laguna, Tenerife (Spain); Anders, Friedrich [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Anderson, Scott F.; Bhardwaj, Vaishali [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Andrews, Brett H. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Aubourg, Éric; Bautista, Julian E. [APC, University of Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cité, F-75205 Paris (France); Bailey, Stephen; Beutler, Florian [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720 (United States); Bastien, Fabienne A.; Berlind, Andreas A.; Bird, Jonathan C. [Department of Physics and Astronomy, Vanderbilt University, VU Station 1807, Nashville, TN 37235 (United States); Beers, Timothy C. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Beifiori, Alessandra [Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstraße, D-85748 Garching (Germany); Bender, Chad F. [Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Bizyaev, Dmitry [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Blake, Cullen H. [Department of Physics and Astronomy, University of Pennsylvania, 219 S. 33rd St., Philadelphia, PA 19104 (United States); and others
2014-04-01
The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the Tenth Public Data Release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R ∼ 22,500 300 fiber spectrograph covering 1.514-1.696 μm. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included. DR10 also roughly doubles the number of BOSS spectra over those included in the Ninth Data Release. DR10 includes a total of 1,507,954 BOSS spectra comprising 927,844 galaxy spectra, 182,009 quasar spectra, and 159,327 stellar spectra selected over 6373.2 deg{sup 2}.
Ahn, Christopher P; Prieto, Carlos Allende; Anders, Friedrich; Anderson, Scott F; Anderton, Timothy; Andrews, Brett H; Aubourg, Éric; Bailey, Stephen; Bastien, Fabienne A; Bautista, Julian E; Beers, Timothy C; Beifiori, Alessandra; Bender, Chad F; Berlind, Andreas A; Beutler, Florian; Bhardwaj, Vaishali; Bird, Jonathan C; Bizyaev, Dmitry; Blake, Cullen H; Blanton, Michael R; Blomqvist, Michael; Bochanski, John J; Bolton, Adam S; Borde, Arnaud; Bovy, Jo; Bradley, Alaina Shelden; Brandt, W N; Brauer, Dorothée; Brinkmann, J; Brownstein, Joel R; Busca, Nicolás G; Carithers, William; Carlberg, Joleen K; Carnero, Aurelio R; Carr, Michael A; Chiappini, Cristina; Chojnowski, S Drew; Chuang, Chia-Hsun; Comparat, Johan; Crepp, Justin R; Cristiani, Stefano; Croft, Rupert A C; Cuesta, Antonio J; Cunha, Katia; da Costa, Luiz N; Dawson, Kyle S; De Lee, Nathan; Dean, Janice D R; Delubac, Timothée; Deshpande, Rohit; Dhital, Saurav; Ealet, Anne; Ebelke, Garrett L; Edmondson, Edward M; Eisenstein, Daniel J; Epstein, Courtney R; Escoffier, Stephanie; Esposito, Massimiliano; Evans, Michael L; Fabbian, D; Fan, Xiaohui; Favole, Ginevra; Castellá, Bruno Femen\\'\\ia; Alvar, Emma Fernández; Feuillet, Diane; Ak, Nurten Filiz; Finley, Hayley; Fleming, Scott W; Font-Ribera, Andreu; Frinchaboy, Peter M; Galbraith-Frew, J G; Garc\\'\\ia-Hernández, D A; Pérez, Ana E Garc\\'\\ia; Ge, Jian; Génova-Santos, R; Gillespie, Bruce A; Girardi, Léo; Hernández, Jonay I González; Gott, J Richard; Gunn, James E; Guo, Hong; Halverson, Samuel; Harding, Paul; Harris, David W; Hasselquist, Sten; Hawley, Suzanne L; Hayden, Michael; Hearty, Frederick R; Ho, Shirley; Hogg, David W; Holtzman, Jon A; Honscheid, Klaus; Huehnerhoff, Joseph; Ivans, Inese I; Jackson, Kelly M; Jiang, Peng; Johnson, Jennifer A; Kirkby, David; Kinemuchi, K; Klaene, Mark A; Kneib, Jean-Paul; Koesterke, Lars; Lan, Ting-Wen; Lang, Dustin; Goff, Jean-Marc Le; Lee, Khee-Gan; Lee, Young Sun; Long, Daniel C; Loomis, Craig P; Lucatello, Sara; Lupton, Robert H; Ma, Bo; Mahadevan, Suvrath; Maia, Marcio A G; Majewski, Steven R; Malanushenko, Elena; Malanushenko, Viktor; Manchado, A; Manera, Marc; Maraston, Claudia; Margala, Daniel; Martell, Sarah L; Masters, Karen L; McBride, Cameron K; McGreer, Ian D; McMahon, Richard G; Ménard, Brice; Mészáros, Sz; Miralda-Escudé, Jordi; Miyatake, Hironao; Montero-Dorta, Antonio D; Montesano, Francesco; More, Surhud; Morrison, Heather L; Muna, Demitri; Munn, Jeffrey A; Myers, Adam D; Nguyen, Duy Cuong; Nichol, Robert C; Nidever, David L; Noterdaeme, Pasquier; Nuza, Sebastián E; O'Connell, Julia E; O'Connell, Robert W; O'Connell, Ross; Olmstead, Matthew D; Oravetz, Daniel J; Owen, Russell; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John K; Pâris, Isabelle; Pepper, Joshua; Percival, Will J; Pérez-Ràfols, Ignasi; Perottoni, Hélio Dotto; Petitjean, Patrick; Pieri, Matthew M; Pinsonneault, M H; Prada, Francisco; Price-Whelan, Adrian M; Raddick, M Jordan; Rahman, Mubdi; Rebolo, Rafael; Reid, Beth A; Richards, Jonathan C; Riffel, Rogério; Robin, Annie C; Rocha-Pinto, H J; Rockosi, Constance M; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Rossi, Graziano; Roy, Arpita; Rubiño-Martin, J A; Sabiu, Cristiano G; Sánchez, Ariel G; Santiago, Basílio; Sayres, Conor; Schiavon, Ricardo P; Schlegel, David J; Schlesinger, Katharine J; Schmidt, Sarah J; Schneider, Donald P; Schultheis, Mathias; Sellgren, Kris; Shen, Yue; Shetrone, Matthew; Shu, Yiping; Simmons, Audrey E; Skrutskie, M F; Slosar, Anže; Smith, Verne V; Snedden, Stephanie A; Sobeck, Jennifer S; Sobreira, Flavia; Stassun, Keivan G; Steinmetz, Matthias; Strauss, Michael A; Streblyanska, Alina; Suzuki, Nao; Swanson, Molly E C; Terrien, Ryan C; Thakar, Aniruddha R; Thomas, Daniel; Thompson, Benjamin A; Tinker, Jeremy L; Tojeiro, Rita; Troup, Nicholas W; Vandenberg, Jan; Magaña, Mariana Vargas; Viel, Matteo; Vogt, Nicole P; Wake, David A; Weaver, Benjamin A; Weinberg, David H; Weiner, Benjamin J; White, Martin; White, Simon D M; Wilson, John C; Wisniewski, John P; Wood-Vasey, W M; Yèche, Christophe; York, Donald G; Zamora, O; Zasowski, Gail; Zehavi, Idit; Zheng, Zheng; Zhu, Guangtun
2013-01-01
The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the tenth public data release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R~22,500 300-fiber spectrograph covering 1.514--1.696 microns. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included.DR10 also roughly doubles the number of BOSS spectra over those included in the ninth data r...
Energy Technology Data Exchange (ETDEWEB)
Eisenstein, Daniel J.; /Arizona U., Astron. Dept. - Steward Observ. /Harvard U., Phys. Dept.; Weinberg, David H.; /Ohio State U.; Agol, Eric; /Washington U., Seattle, Astron. Dept.; Aihara, Hiroaki; /Tokyo U.; Prieto, Carlos Allende; /Laguna U., Tenerife; Anderson, Scott F.; /Washington U., Seattle, Astron. Dept.; Arns, James A.; /Michigan U.; Aubourg, Eric; /APC, Paris /DAPNIA, Saclay; Bailey, Stephen; /LBL, Berkeley; Balbinot, Eduardo; /Rio Grande do Sul U. /Rio de Janeiro Observ.; Barkhouser, Robert; /Johns Hopkins U. /Michigan State U.
2011-01-01
Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. The Baryon Oscillation Spectroscopic Survey (BOSS) will measure redshifts of 1.5 million massive galaxies and Ly{alpha} forest spectra of 150,000 quasars, using the baryon acoustic oscillation (BAO) feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z < 0.7 and at z {approx} 2.5. SEGUE-2, a now-completed continuation of the Sloan Extension for Galactic Understanding and Exploration, measured medium-resolution (R = {lambda}/{Delta}{lambda} 1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE, the Apache Point Observatory Galactic Evolution Experiment, will obtain high-resolution (R {approx} 30,000), high signal-to-noise ratio (S/N {ge} 100 per resolution element), H-band (1.51 {micro}m < {lambda} < 1.70 {micro}m) spectra of 10{sup 5} evolved, late-type stars, measuring separate abundances for {approx} 15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. The Multi-object APO Radial Velocity Large-area Survey (MARVELS) will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m s{sup -1}, {approx} 24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. As of January 2011, SDSS-III has obtained
Heavy baryon spectroscopy from the lattice
Energy Technology Data Exchange (ETDEWEB)
Bowler, K.C.; Kenway, R.D.; Oliveira, O.; Richards, D.G.; Ueberholz, P. [Department of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ (Scotland); Lellouch, L.; Nieves, J.; Sachrajda, C.T.; Stella, N.; Wittig, H. [Physics Department, The University, Southampton SO17 1BJ (United Kingdom)
1996-09-01
The results of an exploratory lattice study of heavy baryon spectroscopy are presented. We have computed the full spectrum of the eight baryons containing a single heavy quark, on a 24{sup 3}{times}48 lattice at {beta}=6.2, using an {ital O}({ital a})-improved fermion action. We discuss the lattice baryon operators and give a method for isolating the contributions of the spin doublets ({Sigma},{Sigma}{sup {asterisk}}), ({Xi}{sup {prime}},{Xi}{sup {asterisk}}), and ({Omega},{Omega}{sup {asterisk}}) to the correlation function of the relevant operator. We compare our results with the available experimental data and find good agreement in both the charm and the {ital b}-quark sectors, despite the long extrapolation in the heavy quark mass needed in the latter case. We also predict the masses of several undiscovered baryons. We compute the {Lambda}-pseudoscalar meson and {Sigma}-{Lambda} mass splittings. Our results, which have errors in the range 10{endash}30{percent}, are in good agreement with the experimental numbers. For the {Sigma}{sup {asterisk}}-{Sigma} mass splitting, we find results considerably smaller than the experimental values for both the charm and the {ital b}-flavored baryons, although in the latter case the experimental results are still preliminary. This is also the case for the lattice results for the hyperfine splitting for the heavy mesons. {copyright} {ital 1996 The American Physical Society.}
Strong decays of baryons and missing resonances
Bijker, R.; Ferretti, J.; Galatà, G.; García-Tecocoatzi, H.; Santopinto, E.
2016-10-01
We provide results for the open-flavor strong decays of strange and nonstrange baryons into a baryon-vector/pseudoscalar meson pair. The decay amplitudes are computed in the 3P0 pair-creation model, where s s ¯ pair-creation suppression is included for the first time in the baryon sector, in combination with the U (7 ) and hypercentral models. The effects of this s s ¯ suppression mechanism cannot be reabsorbed in a redefinition of the model parameters or in a different choice of the 3P0 model vertex factor. Our results for the decay amplitudes are compared with the existing experimental data and previous 3P0 and elementary meson emission model calculations. In this respect, we show that distinct quark models differ in the number of missing resonances they predict and also in the quantum numbers of states. Therefore, future experimental results will be important in order to disentangle different models of baryon structure. Finally, in the appendixes, we provide some details of our calculations, including the derivation of all relevant flavor couplings with strangeness suppression. This derivation may be helpful to calculate the open-flavor decay amplitudes starting from other models of baryons.
Papastergis, Emmanouil; Huang, Shan; Giovanelli, Riccardo; Haynes, Martha P
2012-01-01
We use both an HI-selected and an optically-selected galaxy sample to directly measure the abundance of galaxies as a function of their "baryonic" mass (stars + atomic gas). Stellar masses are calculated based on optical data from the Sloan Digital Sky Survey (SDSS) and atomic gas masses are calculated using atomic hydrogen (HI) emission line data from the Arecibo Legacy Fast ALFA (ALFALFA) survey. By using the technique of abundance matching, we combine the measured baryonic function (BMF) of galaxies with the dark matter halo mass function in a LCDM universe, in order to determine the galactic baryon fraction as a function of host halo mass. We find that the baryon fraction of low-mass halos is much smaller than the cosmic value, even when atomic gas is taken into account. We find that the galactic baryon deficit increases monotonically with decreasing halo mass, in contrast with previous studies which suggested an approximately constant baryon fraction at the low-mass end. We argue that the observed baryon...
Heavy Baryons in a Quark Model
Energy Technology Data Exchange (ETDEWEB)
Winston Roberts; Muslema Pervin
2007-11-14
A quark model is applied to the spectrum of baryons containing heavy quarks. The model gives masses for the known heavy baryons that are in agreement with experiment, but for the doubly-charmed baryon $\\Xi_{cc}$, the model prediction is too heavy. Mixing between the $\\Xi_Q$ and $\\Xi_Q^\\prime$ states is examined and is found to be small for the lowest lying states. In contrast with this, mixing between the $\\Xi_{bc}$ and $\\Xi_{bc}^\\prime$ states is found to be large, and the implication of this mixing for properties of these states is briefly discussed. We also examine heavy-quark spin-symmetry multiplets, and find that many states in the model can be placed in such multiplets.
Compressed Baryonic Matter: from Nuclei to Pulsars
Xu, Renxin
2013-01-01
Our world is wonderful because of the negligible baryonic part although unknown dark matter and dark energy dominate the Universe. Those nuclei in the daily life are forbidden to fuse by compression due to the Coulomb repulse, nevertheless, it is usually unexpected in extraterrestrial extreme-environments: the gravity in a core of massive evolved star is so strong that all the other forces (including the Coulomb one) could be neglected. Compressed baryonic matter is then produced after supernova, manifesting itself as pulsar-like stars observed. The study of this compressed baryonic matter can not only be meaningful in fundamental physics (e.g., the elementary color interaction at low-energy scale, testing gravity theories, detecting nano-Hertz background gravitational waves), but has also profound implications in engineering applications (including time standard and navigation), and additionally, is focused by Chinese advanced telescopes, either terrestrial or in space. Historically, in 1930s, L. Landau spec...
Spectroscopy of charmed baryons from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Padmanath, M. [Univ. of Graz (Austria). Inst. of Physics; Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mathur, Nilmani [Tata Institute of Fundamental Research, Bombay (India); Peardon, Michael [Trinity College, Dublin (Ireland)
2015-01-01
We present the ground and excited state spectra of singly, doubly and triply charmed baryons by using dynamical lattice QCD. A large set of baryonic operators that respect the symmetries of the lattice and are obtained after subduction from their continuum analogues are utilized. Using novel computational techniques correlation functions of these operators are generated and the variational method is exploited to extract excited states. The lattice spectra that we obtain have baryonic states with well-defined total spins up to 7/2 and the low lying states remarkably resemble the expectations of quantum numbers from SU(6) x O(3) symmetry. Various energy splittings between the extracted states, including splittings due to hyperfine as well as spin-orbit coupling, are considered and those are also compared against similar energy splittings at other quark masses.
Dark Matter and the Baryon Asymmetry
Farrar, G R; Farrar, Glennys R.; Zaharijas, Gabrijela
2006-01-01
We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\mathcal{O}$(10%) or more, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$. Two concrete examples are given, one of which can be excluded on observational grounds.
Production and decay of charmed baryons
Hosaka, Atsushi; Hiyama, Emiko; Kim, SangHo; Kim, Hyun-Chul; Nagahiro, Hideko; Noumi, Hiroyuki; Oka, Makoto; Shirotori, Kotaro; Yoshida, Tetsuya; Yasui, Shigehiro
2016-10-01
In this paper, we discuss reactions involving charmed baryons to explore their unique features. A well known phenomenon, the separation of the two internal motions of the ρ and λ types of a three-quark system is revisited. First we discuss the mass spectrum of low lying excitations as function of the heavy quark mass, smoothly connecting the SU (3) and heavy quark limits. The properties of these modes can be tested in the production and decay reactions of the baryons. For production, we consider a one step process which excites dominantly λ modes. We find abundant production rates for some of the excited states. For decay, we study a pion emission process which provides a clean tool to test the structure of heavy quark systems due to the well controlled low energy dynamics of pions and quarks. Both production and decay of charmed baryons are issues for future experiments at J-PARC.
Exciting Baryons: now and in the future
Pennington, M R
2011-01-01
This is the final talk of NSTAR2011 conference. It is not a summary talk, but rather a looking forward to what still needs to be done in excited baryon physics. In particular, we need to hone our tools connecting experimental inputs with QCD. At present we rely on models that often have doubtful connections with the underlying theory, and this needs to be dramatically improved, if we are to reach definitive conclusions about the relevant degrees of freedom of excited baryons. Conclusions that we want to have by NSTAR2021.
Decuplet baryons in a hot medium
Energy Technology Data Exchange (ETDEWEB)
Azizi, K.; Bozkir, G. [Dogus Univ., Istanbul (Turkey). Dept. of Physics
2016-10-15
The thermal properties of the light decuplet baryons are investigated in the framework of the thermal QCD sum rules. In particular, the behavior of the mass and residue of the Δ, Σ*, Ξ*, and Ω baryons with respect to temperature are analyzed taking into account the additional operators appearing in the Wilson expansion at finite temperature. It is found that the mass and residue of these particles remain overall unaffected up to T ≅ 150 MeV but, beyond this point, they start to diminish considerably. (orig.)
Constructing Hybrid Baryons with Flux Tubes
Capstick, Simon; Capstick, Simon; Page, Philip R.
1999-01-01
Hybrid baryon states are described in quark potential models as having explicit excitation of the gluon degrees of freedom. Such states are described in a model motivated by the strong coupling limit of Hamiltonian lattice gauge theory, where three flux tubes meeting at a junction play the role of the glue. The adiabatic approximation for the quark motion is used, and the flux tubes and junction are modeled by beads which are attracted to each other and the quarks by a linear potential, and vibrate in various string modes. Quantum numbers and estimates of the energies of the lightest hybrid baryons are provided.
Heavy flavor baryons in hypercentral model
Indian Academy of Sciences (India)
Bhavin Patel; Ajay Kumar Rai; P C Vinodkumar
2008-05-01
Heavy flavor baryons containing single and double charm (beauty) quarks with light flavor combinations are studied using the hypercentral description of the three-body problem. The confinement potential is assumed as hypercentral Coulomb plus power potential with power index . The ground state masses of the heavy flavor, $J^{P} = \\dfrac{1}{2}^{+}$ and $\\dfrac{3}{2}^{+}$ baryons are computed for different power indices, starting from 0.5 to 2.0. The predicted masses are found to attain a saturated value in each case of quark combinations beyond the power index = 1.0.
Meson Production and Baryon Resonances at CLAS
Energy Technology Data Exchange (ETDEWEB)
Volker Burkert
2011-02-01
I give a brief overview of the exploration of baryon properties in meson photo- and electroproduction. These processes provide ample information for the study of electromagnetic couplings of baryon resonances and to search for states, yet to be discovered. The CLAS detector, combined with the use of energy-tagged polarized photons and polarized electrons, as well as polarized targets and the measurement of recoil polarization, provide the tools for a comprehensive nucleon resonance program. I briefly present the status of this program, prospects for the next few years, and plans for the Jefferson Lab 12 GeV upgrade.
Heavy Baryon Transitions in a Relativistic Three-Quark Model
Ivanov, M A; Kroll, P; Lyubovitskij, V E
1997-01-01
Exclusive semileptonic decays of bottom and charm baryons are considered within a relativistic three-quark model with a Gaussian shape for the baryon-three-quark vertex and standard quark propagators. We calculate the baryonic Isgur-Wise functions, decay rates and asymmetry parameters.
Algebraic Treatment of Collective Excitations in Baryon Spectroscopy
Bijker, R
1993-01-01
We present an algebraic U(7) model for baryons which encompasses both single-particle and collective forms of quark dynamics. The mass operator by construction preserves the permutation symmetry between identical quarks. The underlying geometric structure of baryons is discussed in terms of a rigid rotating and vibrating oblate top shape. The model is applied to the mass spectrum of nonstrange baryons.
Strangeness -2 and -3 Baryons in a Constituent Quark Model
Energy Technology Data Exchange (ETDEWEB)
Muslema Pervin; Winston Roberts
2007-09-19
We apply a quark model developed in earlier work to the spectrum of baryons with strangeness -2 and -3. The model describes a number of well-established baryons successfully, and application to cascade baryons allows the quantum numbers of some known states to be deduced.
Energy Technology Data Exchange (ETDEWEB)
Knippschild, Bastian
2012-03-05
Quantum Chromodynamics (QCD) is the theory of strong interactions, one of the four fundamental forces in our Universe. It describes the interaction of gluons and quarks which build up hadrons like protons and neutrons. Most of the visible matter in our universe is made of protons and neutrons. Hence, we are interested in their fundamental properties like their masses, their distribution of charge and their shape. The only known theoretical, non-perturbative and ab initio method to investigate hadron properties at low energies is lattice Quantum Chromodynamics (lattice QCD). However, up-to-date simulations (especially for baryonic quantities) do not achieve the accuracy of experiments. In fact, current simulations do not even reproduce the experimental values for the form factors. The question arises wether these deviations can be explained by systematic effects in lattice QCD simulations. This thesis is about the computation of nucleon form factors and other hadronic quantities from lattice QCD. So called Wilson fermions are used and the u- and d-quarks are treated fully dynamically. The simulations were performed using gauge ensembles with a range of lattice spacings, volumes and pion masses. First of all, the lattice spacing was set to be able to make contact between the lattice results and their experimental complement and to be able to perform a continuum extrapolation. The light quark mass has been computed and found to be m{sub ud}{sup MS}(2 GeV)=3.03(17)(38) MeV. This value is in good agreement with values from experiments and other lattice determinations. Electro-magnetic and axial form factors of the nucleon have been calculated. From these form factors the nucleon radii and the coupling constants were computed. The different ensembles enabled us to investigate systematically the dependence of these quantities on the volume, the lattice spacing and the pion mass. Finally we perform a continuum extrapolation and chiral extrapolations to the physical point
The CMU Baryon Amplitude Analysis Program
Bellis, Matt
2007-05-01
The PWA group at Carnegie Mellon University has developed a comprehensive approach and analysis package for the purpose of extracting the amplitudes for photoproduced baryon resonances. The end goal is to identify any missing resonances that are predicted by the constituent quark model, but not definitively observed in experiments. The data comes from the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab.
Multiinstanton ladders in baryon number violating processes
Lazarides, G
1995-01-01
We estimate the contribution of a class of multiinstanton ladder graphs to baryon and lepton number violating processes in the standard model. We find that this contribution is negligible and does not alter the high energy behavior of the leading semiclassical approximation.
Beauty baryon decays: a theoretical overview
Wang, Yu-Ming
2014-11-01
I overview the theoretical status and recent progress on the calculations of beauty baryon decays focusing on the QCD aspects of the exclusive semi-leptonic Λb → plμ decay at large recoil and theoretical challenges of radiative and electro-weak penguin decays Λb → Λγ,Λl+l-.
Baryon Ratios in Quark-Gluon Plasma
Institute of Scientific and Technical Information of China (English)
MA Zhong-Biao; MIAO Hong; GAO Chong-Shou
2003-01-01
A way to calculate ratios of baryon produced from quark gluon plasma in relativistic heavyion collisionsis presented. It is assumed that at the beginning of the hadronization there are diquarks and anti-diquarks in the quarkmatter. The number of three-quark states is distributed between the corresponding multiplets, and hadronic decays aretaken into account. The results are shown at last.
Baryons in the unquenched quark model
Bijker, R; Lopez-Ruiz, M A; Santopinto, E
2016-01-01
In this contribution, we present the unquenched quark model as an extension of the constituent quark model that includes the effects of sea quarks via a $^{3}P_{0}$ quark-antiquark pair-creation mechanism. Particular attention is paid to the spin and flavor content of the proton, magnetic moments and $\\beta$ decays of octet baryons.
Light element synthesis in baryon isocurvature models
Kumar, D L P
2006-01-01
The prejudice against baryon isocurvature models is primarily because of their inconsistency with early universe light element nucleosynthesis results. We propose that incipient low metallicity (Pop II) star forming regions can be expected to have environments conducive to Deuterium production by spallation, up to levels observed in the universe.
Baryons in a chiral constituent quark model
Glozman, L Ya
1998-01-01
In the low-energy regime light and strange baryons should be considered as systems of constituent quarks with confining interaction and a chiral interaction that is mediated by Goldstone bosons as well as by vector and scalar mesons. The flavor-spin structure and sign of the short-range part of the spin-spin force reduces the $SU(6)_{FS}$ symmetry down to $SU(3)_F \\times SU(2)_S$, induces hyperfine splittings and provides correct ordering of the lowest states with positive and negative parity. There is a cancellation of the tensor force from pseudoscalar- and vector-exchanges in baryons. The spin-orbit interactions from $\\rho$-like and $\\omega$-like exchanges also cancel each other in baryons while they produce a big spin-orbit force in NN system. A unified description of light and strange baryon spectra calculated in a semirelativistic framework is presented. It is demonstrated that the same short-range part of spin-spin interaction between the constituent quarks induces a strong short-range repulsion in $NN...
Valley Singularities and Baryon Number Violation
Provero, P
1994-01-01
We consider the valley--method computation of the inclusive cross section of baryon number violating processes in the Standard Model. We show that any physically correct model of the valley action should present a singularity in the saddle point valley parameters as functions of the energy of the process. This singularity prevents the saddle point configuration from collapsing into the perturbative vacuum.
Espinosa, Ismael; Gonzalez, Hortensia; Quiza, Jorge; Gonazalez, J. Jesus; Arroyo, Ruben; Lara, Ritaluz
1995-01-01
Oscillation of electrical activity has been found in many nervous systems, from invertebrates to vertebrates including man. There exists experimental evidence of very simple circuits with the capability of oscillation. Neurons with intrinsic oscillation have been found and also neural circuits where oscillation is a property of the network. These two types of oscillations coexist in many instances. It is nowadays hypothesized that behind synchronization and oscillation there is a system of coupled oscillators responsible for activities that range from locomotion and feature binding in vision to control of sleep and circadian rhythms. The huge knowledge that has been acquired on oscillators from the times of Lord Rayleigh has made the simulation of neural oscillators a very active endeavor. This has been enhanced with more recent physiological findings about small neural circuits by means of intracellular and extracellular recordings as well as imaging methods. The future of this interdisciplinary field looks very promising; some researchers are going into quantum mechanics with the idea of trying to provide a quantum description of the brain. In this work we describe some simulations using neuron models by means of which we form simple neural networks that have the capability of oscillation. We analyze the oscillatory activity with root locus method, cross-correlation histograms, and phase planes. In the more complicated neural network models there is the possibility of chaotic oscillatory activity and we study that by means of Lyapunov exponents. The companion paper shows an example of that kind.
Magnetic moments of negative-parity baryons in QCD
Aliev, T M
2014-01-01
Using the most general form of the interpolating current for the octet baryons, the magnetic moments of the negative-parity baryons are calculated within the light-cone sum rules. The contributions coming from diagonal transitions of the positive-parity baryons, and also from non-diagonal transition between positive and negative-parity baryons are eliminated by considering the combinations of different sum rules corresponding to the different Lorentz structures. A comparison of our results on magnetic moments of the negative-parity baryons with the other approaches existing in literature is presented.
Baryon number violation catalysed by grand unified monopoles
Ellis, Jonathan Richard; Olive, Keith A
1982-01-01
It has been recognized for some time that grand unified monopoles may catalyze Delta B not=0 processes. The authors obtain model-independent upper bounds on the rates for such reactions from the survival of the baryon number generated in the early Universe and from present-day baryon stability. These constraints are compatible with recent estimates of large baryon number violating monopole cross sections, but a monopole flux close to present experimental upper limits could be detectable in forthcoming baryon decay experiments. The authors mention signatures for monopole-induced baryon 'decay' and point out that it could be used to solve the energy crisis.
Holographic black hole engineering at finite baryon chemical potential
Rougemont, Romulo
2016-01-01
This is a contribution for the Proceedings of the Conference Hot Quarks 2016, held at South Padre Island, Texas, USA, 12-17 September 2016. I briefly review some thermodynamic and baryon transport results obtained from a bottom-up Einstein-Maxwell-Dilaton holographic model engineered to describe the physics of the quark-gluon plasma at finite temperature and baryon density. The results for the equation of state, baryon susceptibilities, and the curvature of the crossover band are in quantitative agreement with the corresponding lattice QCD results with $2+1$ flavors and physical quark masses. Baryon diffusion is predicted to be suppressed by increasing the baryon chemical potential.
Richards, Emily E; Barnes, K L; Staudaher, S; Dale, D A; Braun, T T; Wavle, D C; Dalcanton, J J; Bullock, J S; Chandar, R
2016-01-01
We present a combination of new and archival neutral hydrogen (HI) observations and new ionized gas spectroscopic observations for sixteen galaxies in the statistically representative EDGES kinematic sample. HI rotation curves are derived from new and archival radio synthesis observations from the Very Large Array (VLA) as well as processed data products from the Westerbork Radio Synthesis Telescope (WSRT). The HI rotation curves are supplemented with optical spectroscopic integral field unit (IFU) observations using SparsePak on the WIYN 3.5 m telescope to constrain the central ionized gas kinematics in twelve galaxies. The full rotation curves of each galaxy are decomposed into baryonic and dark matter halo components using 3.6$\\mu$m images from the Spitzer Space Telescope for the stellar content, the neutral hydrogen data for the atomic gas component, and, when available, CO data from the literature for the molecular gas component. Differences in the inferred distribution of mass are illustrated under fixe...
Melzer, J
1976-01-01
During the preparation of this compilation, many people contributed; the compilers wish to thank all of them. In particular they appreciate the efforts of V. Gilbertson, the manuscript typist, and those of K. C. Bregand, J. A. Kiley, and W. H. McPherson, who gave editorial assistance. They would like to thank Dr. J. R. Schwartz for his cooperation and encouragement. In addition, they extend their grati tude to Dr. L. Wilson of the Air Force Weapons Laboratory, who gave the initial impetus to this project. v Contents I. I ntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . 11. Organization ofthe Spectroscopic Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Methods of Production and Experimental Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Band Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2...
Energy Technology Data Exchange (ETDEWEB)
Atakishiyev, N.M. [Instituto de Matematicas. Universidad Nacional Autonoma de Mexico. Cuernavaca, Morelos (Mexico); Jafarov, E.I.; Nagiyev, S.M. [Institute of Physics, Azerbaijan Academy of Sciences. Baku, Azerbaijan (Azerbaijan); Wolf, K.B. [Instituto de Investigaciones en Matematicas Aplicadas y en Sistemas. Universidad Nacional Autonoma de Mexico. Cuernavaca, Morelos (Mexico)
1998-10-01
Meixner oscillators have a ground state and an energy spectrum that is equally spaced; they are a two-parameter family of models that satisfy a Hamiltonian equation with a difference operator. Meixner oscillators include as limits and particular cases the Charlier, Kravchuk and Hermite (common quantum-mechanical) harmonic oscillators. By the Sommerfeld-Watson transformation they are also related with a relativistic model of the linear harmonic oscillator, built in terms of the Meixner-Pollaczek polynomials, and their continuous weight function. We construct explicitly the corresponding coherent states with the dynamical symmetry group Sp(2,R). The reproducing kernel for the wavefunctions of these models is also found. (Author)
Comparat, Johan; Bacon, Roland; Mostek, Nick J; Newman, Jeffrey A; Schlegel, David J; Yèche, Christophe
2013-01-01
The next generation of wide-field spectroscopic redshift surveys will map the large-scale galaxy distribution in the redshift range 0.7< z<2 to measure baryonic acoustic oscillations (BAO). The primary optical signature used in this redshift range comes from the [OII] emission line doublet, which provides a unique redshift identification that can minimize confusion with other single emission lines. To derive the required spectrograph resolution for these redshift surveys, we simulate observations of the [OII] (3727,3729) doublet for various instrument resolutions, and line velocities. We foresee two strategies about the choice of the resolution for future spectrographs for BAO surveys. For bright [OII] emitter surveys ([OII] flux ~30.10^{-17} erg /cm2/s like SDSS-IV/eBOSS), a resolution of R~3300 allows the separation of 90 percent of the doublets. The impact of the sky lines on the completeness in redshift is less than 6 percent. For faint [OII] emitter surveys ([OII] flux ~10.10^{-17} erg /cm2/s like ...
Eriksen, Martin
2015-01-01
In the first paper of this series, we studied the effect of baryon acoustic oscillations (BAO), redshift space distortions (RSD) and weak lensing (WL) on measurements of angular cross-correlations in narrow redshift bins. Paper-II presented a multitracer forecast as Figures of Merit (FoM), combining a photometric and spectroscopic stage-IV survey. The uncertainties from galaxy bias, the way light traces mass, is an important ingredient in the forecast. Fixing the bias would increase our FoM equivalent to 3.3 times larger area for the combined constraints. This paper focus on how the modelling of bias affect these results. In the combined forecast, lensing both help and benefit from the improved bias measurements in overlapping surveys after marginalizing over the cosmological parameters. Adding a second lens population in counts-shear does not have a large impact on bias error, but removing all counts-shear information increases the bias error in a significant way. We also discuss the relative impact of WL, m...
Predicting Future Space Near-IR Grism Surveys using the WFC3 Infrared Spectroscopic Parallels Survey
Colbert, James W; Atek, Hakim; Bunker, Andrew; Rafelski, Marc; Ross, Nathaniel; Scarlata, Claudia; Bedregal, Alejandro; Dominguez, Alberto; Dressler, Alan; Henry, Alaina; Malkan, Matt; Martin, Crystal L; Masters, Dan; McCarthy, Patrick; Siana, Brian
2013-01-01
We present near-infrared emission line counts and luminosity functions from the HST WFC3 Infrared Spectroscopic Parallels (WISP) program for 29 fields observed using both the G102 and G141 grism. Altogether we identify 1048 emission line galaxies with observed equivalent widths greater than 40 Angstroms, 467 of which have multiple detected emission lines. The WISP survey is sensitive to fainter flux levels (3-5x10^{-17} ergs/s/cm^2) than the future space near-infrared grism missions aimed at baryonic acoustic oscillation cosmology (1-4x10^{-16} ergs/s/cm^2), allowing us to probe the fainter emission line galaxies that the shallower future surveys may miss. Cumulative number counts of 0.7
The mass spectrum of double heavy baryons in new potential quark models
Directory of Open Access Journals (Sweden)
Kovalenko Vladimir
2017-01-01
Full Text Available A new approach to study the mass spectrum of double heavy baryons (QQ′q containing strange and charmed quarks is proposed. It is based on the separation of variables in the Schrodinger equation in the prolate spheroidal coordinates. Two nonrelativistic potential models are considered. In the first model, the interaction potential of the quarks is the sum of the Coulomb and non-spherically symmetrical linear confinement potential. In the second model it is assumed that the quark confinement provided by a spherically symmetric harmonic oscillator potential. In both models the mass spectrum is calculated, and a comparison with previous results from other models is performed.
The impact of baryons on massive galaxy clusters: halo structure and cluster mass estimates
Henson, Monique A.; Barnes, David J.; Kay, Scott T.; McCarthy, Ian G.; Schaye, Joop
2017-03-01
We use the BAHAMAS (BAryons and HAloes of MAssive Systems) and MACSIS (MAssive ClusterS and Intercluster Structures) hydrodynamic simulations to quantify the impact of baryons on the mass distribution and dynamics of massive galaxy clusters, as well as the bias in X-ray and weak lensing mass estimates. These simulations use the subgrid physics models calibrated in the BAHAMAS project, which include feedback from both supernovae and active galactic nuclei. They form a cluster population covering almost two orders of magnitude in mass, with more than 3500 clusters with masses greater than 1014 M⊙ at z = 0. We start by characterizing the clusters in terms of their spin, shape and density profile, before considering the bias in both weak lensing and hydrostatic mass estimates. Whilst including baryonic effects leads to more spherical, centrally concentrated clusters, the median weak lensing mass bias is unaffected by the presence of baryons. In both the dark matter only and hydrodynamic simulations, the weak lensing measurements underestimate cluster masses by ≈10 per cent for clusters with M200 ≤ 1015 M⊙ and this bias tends to zero at higher masses. We also consider the hydrostatic bias when using both the true density and temperature profiles, and those derived from X-ray spectroscopy. When using spectroscopic temperatures and densities, the hydrostatic bias decreases as a function of mass, leading to a bias of ≈40 per cent for clusters with M500 ≥ 1015 M⊙. This is due to the presence of cooler gas in the cluster outskirts. Using mass weighted temperatures and the true density profile reduces this bias to 5-15 per cent.
Li, Fenfang; Nguyen, Dang Minh; Ohl, Claus-Dieter
2016-01-01
We report about an intriguing boiling regime occurring for small heaters embedded on the boundary in subcooled water. The microheater is realized by focusing a continuous wave laser beam to about $10\\,\\mu$m in diameter onto a 165\\,nm-thick layer of gold, which is submerged in water. After an initial vaporous explosion a single bubble oscillates continuously and repeatably at several $100\\,$kHz. The microbubble's oscillations are accompanied with bubble pinch-off leading to a stream of gaseous bubbles into the subcooled water. The self-driven bubble oscillation is explained with a thermally kicked oscillator caused by the non-spherical collapses and by surface pinning. Additionally, Marangoni stresses induce a recirculating streaming flow which transports cold liquid towards the microheater reducing diffusion of heat along the substrate and therefore stabilizing the phenomenon to many million cycles. We speculate that this oscillate boiling regime may allow to overcome the heat transfer thresholds observed dur...
Exotic baryon resonances in the Skyrme model
Diakonov, Dmitri
2008-01-01
We outline how one can understand the Skyrme model from the modern perspective. We review the quantization of the SU(3) rotations of the Skyrmion, leading to the exotic baryons that cannot be made of three quarks. It is shown that in the limit of large number of colours the lowest-mass exotic baryons can be studied from the kaon-Skyrmion scattering amplitudes, an approach known after Callan and Klebanov. We follow this approach and find, both analytically and numerically, a strong Theta+ resonance in the scattering amplitude that is traced to the rotational mode. The Skyrme model does predict an exotic resonance Theta+ but grossly overestimates the width. To understand better the factors affecting the width, it is computed by several methods giving, however, identical results. In particular, we show that insofar as the width is small, it can be found from the transition axial constant. The physics leading to a narrow Theta+ resonance is briefly reviewed and affirmed.
Two Baryons with Twisted Boundary Conditions
Energy Technology Data Exchange (ETDEWEB)
Briceno, Raul [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Davoudi, Zohreh [Univ. of Washington, Seattle, WA (United States) and Institute for Nuclear Theory, Seattle, WA (United States); Luu, Thomas [Lawrence Livermore National Laboratory, Livermore, CA (United States); Savage, Martin [Univ. of Washington, Seattle, WA (United States) and Institute for Nuclear Theory, Seattle, WA (United States)
2014-04-01
The quantization condition for two particle systems with arbitrary number of two-body open coupled-channels, spin and masses in a finite cubic volume is presented. The condition presented is in agreement with all previous studies of two-body systems in a finite volume. The result is fully relativistic and holds for all momenta below inelastic thresholds and is exact up to exponential volume corrections that are governed by m{sub {pi}} L, where m{sub {pi}} is the pion mass and L is the spatial extent of my box. Its implication for the studies of coupled-channel baryon-baryon systems is discussed, and the necessary tools for implementing the formalism are review.
Baryon Spectrum Analysis using Covariant Constraint Dynamics
Whitney, Joshua; Crater, Horace
2012-03-01
The energy spectrum of the baryons is determined by treating each of them as a three-body system with the interacting forces coming from a set of two-body potentials that depend on both the distance between the quarks and the spin and orbital angular momentum coupling terms. The Two Body Dirac equations of constraint dynamics derived by Crater and Van Alstine, matched with the quasipotential formalism of Todorov as the underlying two-body formalism are used, as well as the three-body constraint formalism of Sazdjian to integrate the three two-body equations into a single relativistically covariant three body equation for the bound state energies. The results are analyzed and compared to experiment using a best fit method and several different algorithms, including a gradient approach, and Monte Carlo method. Results for all well-known baryons are presented and compared to experiment, with good accuracy.
The Baryonic Tully-Fisher Relation.
McGaugh; Schombert; Bothun; de Blok WJ
2000-04-20
We explore the Tully-Fisher relation over five decades in stellar mass in galaxies with circular velocities ranging over 30 less, similarVc less, similar300 km s-1. We find a clear break in the optical Tully-Fisher relation: field galaxies with Vc less, similar90 km s-1 fall below the relation defined by brighter galaxies. These faint galaxies, however, are very rich in gas; adding in the gas mass and plotting the baryonic disk mass Md=M*+Mgas in place of luminosity restores the single linear relation. The Tully-Fisher relation thus appears fundamentally to be a relation between rotation velocity and total baryonic mass of the form Md~V4c.
A Schwarzschild-like model for baryons
Singleton, D.; Yoshida, A.
2002-06-01
We present a toy model of baryons using singular solutions of the SU(2) Yang-Mill-Higgs (YMH) field equations, which bears some similarity to the Schwarzschild solution of general relativity. The SU (2) solutions are used as a background field into which a scalar, SU (2) test particle is placed. This can be compared to placing an electrically charged particle in a Coulomb background field, except the SU (2) YMH solutions are singular on a spherical membrane thus trapping (confining) the test particle inside the sphere in a manner similar to certain bag models of baryons. An interesting consequence of this model is that the composite system is a fermion even though the original Lagrangian contains only bosonic fields.
Effective Degrees of Freedom in Baryon Spectroscopy
Santopinto, E.; Ferretti, J.
2016-10-01
Three quark and quark-diquark models are characterized by several missing resonances, even if in the latter case the state space is a reduced one. Moreover, even quark-diquark models show some differences in their predictions for missing states. After several years of discussion, we still do not know whether baryons can be completely described in terms of three quark models or if diquark correlations have to be taken into account; another possibility, suggested in Santopinto (Phys Rev C 72:022201, 2005), Ferretti et al. (Phys Rev C 83:065204, 2011) and Galatà and Santopinto (Phys Rev C 86:045202, 2012), is that the previous pictures (three-quark and quark-diquark) represent the dominant descriptions of baryons at different energy scales. New experiments may be planned at Jlab (JLab12), Bes, Belle and LHCb in order to answer this fundamental open question.
Baryon and time asymmetries of the universe
Barnaveli, A T; Barnaveli, Andro; Gogberashvili, Merab
1995-01-01
This paper is devoted to the investigation of connection between two apparent asymmetries of the nature --- time-asymmetry and Baryon Asymmetry of the Universe (BAU). The brief review of this subjects is given. We consider the particle behavior in curved space-time and the possibility of T- and CPT-violation by the universe expansion. If these symmetries are violated we can dispense with the nonequilibrium condition which is usualy considered as the one of necessary ingredients for BAU-generation. Such mechanism of GUT-scale baryogenesis can provide the observed value of baryon asymmetry. We show this on the example of minimal SU(5) model which usually fails to explain the observed BAU without taking into account gravitational effects. Predominance of matter over antimatter and the cosmological arrow of time (the time-direction in which the Universe expands) seem to be connected facts and, possibly, BAU is the one of observable facts of CPT-violation in nature.
A Heavy Quark Symmetry Approach to Baryons
Energy Technology Data Exchange (ETDEWEB)
Albertus, C. [Departamento de Fisica Moderna. Facultad de Ciencias, Universidad de Granada, E-18071 Granada (Spain); Amaro, J.E. [Departamento de Fisica Moderna. Facultad de Ciencias, Universidad de Granada, E-18071 Granada (Spain); Hernandez, E. [Grupo de Fisica Nuclear. Facultad de Ciencias, Universidad de Salamanca, E-37008 Salamanca (Spain); Nieves, J. [Departamento de Fisica Moderna. Facultad de Ciencias, Universidad de Granada, E-18071 Granada (Spain)
2005-06-13
We evaluate different properties of baryons with a heavy c or b quark. The use of Heavy Quark Symmetry (HQS) provides with an important simplification of the non relativistic three body problem which can be solved by means of a simple variational approach. This scheme is able to reproduce previous results obtained with more involved Faddeev calculations. The resulting wave functions are parametrized in a simple manner, and can be used to calculate further observables.
Baryon currents in QCD with compact dimensions
Lucini, B; Pica, C; Lucini, Biagio; Patella, Agostino; Pica, Claudio
2007-01-01
On a compact space with non-trivial cycles, for sufficiently small values of the radii of the compact dimensions, SU(N) gauge theories coupled with fermions in the fundamental representation spontaneously break charge conjugation, time reversal and parity. We show at one loop in perturbation theory that physical signature for this phenomenon is a non-zero baryonic current wrapping around the compact directions. The persistence of this current beyond the perturbative regime is checked by lattice simulations.
Understanding the baryon and meson spectra
Energy Technology Data Exchange (ETDEWEB)
Pennington, Michael R. [JLAB
2013-10-01
A brief overview is given of what we know of the baryon and meson spectra, with a focus on what are the key internal degrees of freedom and how these relate to strong coupling QCD. The challenges, experimental, theoretical and phenomenological, for the future are outlined, with particular reference to a program at Jefferson Lab to extract hadronic states in which glue unambiguously contributes to their quantum numbers.
Baryon spectroscopy with polarization observables from CLAS
Energy Technology Data Exchange (ETDEWEB)
Strauch, Steffen [Univ. of South Carolina, Columbia, SC (United States)
2016-08-01
Meson photoproduction is an important tool in the study of baryon resonances. The spectrum of broad and overlapping nucleon excitations can be greatly clarified by use of polarization observables. The N* program at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) includes experimental studies with linearly and circularly polarized tagged photon beams, longitudinally and transversely polarized nucleon targets, and recoil polarizations. An overview of these experimental studies and recent results will be given.
An algebraic model of baryon spectroscopy
Bijker, R
1999-01-01
We discuss recent calculations of the mass spectrum, electromagnetic and strong couplings of baryon resonances. The calculations are done in a collective constituent model for the nucleon, in which the resonances are interpreted as rotations and vibrations of a symmetric top with a prescribed distribution of the charge and magnetization. We analyze recent data on eta-photo- and eta-electroproduction, and the tensor analyzing power in deuteron scattering.
Screened potential and the baryon spectrum
Vijande, J; Garcilazo, H; Valcarce, A
2003-01-01
We show that in a quark model scheme the use of a screened potential, suggested by lattice QCD, instead of an infinitely rising one with the interquark distance, provides a more adequate description of the high-energy baryon spectrum. In particular an almost perfect parallelism between the predicted and observed number of states comes out throwing new light about the so-called missing resonance problem.
Baryons in chiral constituent quark model
Glozman, L Ya
1996-01-01
Beyond the spontaneous chiral symmetry breaking scale light and strange baryons should be considered as systems of three constituent quarks with an effective confining interaction and a flavor-spin chiral interaction that is mediated by the octet of Goldstone bosons (pseudoscalar mesons) between the constituent quarks. One cannot exclude, however, the possibility that this flavor-spin interaction has an appreciable vector- and higher meson exchange component.
Charmed bottom baryon spectroscopy from lattice QCD
Brown, Zachary S; Meinel, Stefan; Orginos, Kostas
2014-01-01
We calculate the masses of baryons containing one, two, or three heavy quarks using lattice QCD. We consider all possible combinations of charm and bottom quarks, and compute a total of 36 different states with $J^P = \\frac12^+$ and $J^P = \\frac32^+$. We use domain-wall fermions for the up, down, and strange quarks, a relativistic heavy-quark action for the charm quarks, and nonrelativistic QCD for the bottom quarks. Our analysis includes results from two different lattice spacings and seven different pion masses. We perform extrapolations of the baryon masses to the continuum limit and to the physical pion mass using $SU(4|2)$ heavy-hadron chiral perturbation theory including $1/m_Q$ and finite-volume effects. For the 14 singly heavy baryons that have already been observed, our results agree with the experimental values within the uncertainties. We compare our predictions for the hitherto unobserved states with other lattice calculations and quark-model studies.
Baryons, Neutrinos, Feedback and Weak Gravitational Lensing
Harnois-Déraps, Joachim; Viola, Massimo; Heymans, Catherine
2014-01-01
(Abridged) The effect of baryonic feedback on the dark matter mass distribution is generally considered to be a nuisance to weak gravitational lensing. Measurements of cosmological parameters are affected as feedback alters the cosmic shear signal on angular scales smaller than a few arcminutes. Recent progress on the numerical modelling of baryon physics has shown that this effect could be so large that, rather than being a nuisance, the effect can be constrained with current weak lensing surveys, hence providing an alternative astrophysical insight on one of the most challenging questions of galaxy formation. In order to perform our analysis, we construct an analytic fitting formula that describes the effect of the baryons on the mass power spectrum. This fitting formula is based on three scenarios of the OWL hydrodynamical simulations. It is specifically calibrated for $z<1.5$, where it models the simulations to an accuracy that is better than $2\\%$ for scales $k<10 h\\mbox{Mpc}^{-1}$ and better than ...
Tidal Dwarf Galaxies and Missing Baryons
Directory of Open Access Journals (Sweden)
Frederic Bournaud
2010-01-01
Full Text Available Tidal dwarf galaxies form during the interaction, collision, or merger of massive spiral galaxies. They can resemble “normal” dwarf galaxies in terms of mass, size, and become dwarf satellites orbiting around their massive progenitor. They nevertheless keep some signatures from their origin, making them interesting targets for cosmological studies. In particular, they should be free from dark matter from a spheroidal halo. Flat rotation curves and high dynamical masses may then indicate the presence of an unseen component, and constrain the properties of the “missing baryons,” known to exist but not directly observed. The number of dwarf galaxies in the Universe is another cosmological problem for which it is important to ascertain if tidal dwarf galaxies formed frequently at high redshift, when the merger rate was high, and many of them survived until today. In this paper, “dark matter” is used to refer to the nonbaryonic matter, mostly located in large dark halos, that is, CDM in the standard paradigm, and “missing baryons” or “dark baryons” is used to refer to the baryons known to exist but hardly observed at redshift zero, and are a baryonic dark component that is additional to “dark matter”.
Narrow linewidth pulsed optical parametric oscillator
Indian Academy of Sciences (India)
S Das
2010-11-01
Tunable narrow linewidth radiation by optical parametric oscillation has many applications, particularly in spectroscopic investigation. In this paper, different techniques such as injection seeding, use of spectral selecting element like grating, grating and etalon in combination, grazing angle of incidence, entangled cavity configuration and type-II phase matching have been discussed for generating tunable narrow linewidth radiation by singly resonant optical parametric oscillation process.
Fragmentation Functions for Heavy Baryons in the Recombination Model
Institute of Scientific and Technical Information of China (English)
彭茹
2011-01-01
Using the shower parton distributions determined by the recombination model, we predict the fragmentation functions for heavy baryons. Then we obtain the completed fragmentation functions of heavy quarks (c and b) splitting into their hadrons (mesons and baryons containing one heavy valence quark). The calculated process shows that the fragmentation functions for mesons and baryons are not independent if the hadronization of the shower partons is taken into account.%Using the shower parton distributions determined by the recombination model,we predict the fragmentation functions for heavy baryons.Then we obtain the completed fragmentation functions of heavy quarks(c and b)splitting into their hadrons(mesons and baryons containing one heavy valence quark).The calculated process shows that the fragmentation functions for mesons and baryons are not independent if the hadronization of the shower partons is taken into account.
High statistics analysis using anisotropic clover lattices: (III) Baryon-baryon interactions
Energy Technology Data Exchange (ETDEWEB)
Beane, S; Detmold, W; Lin, H; Luu, T; Orginos, K; Savage, M; Torok, A; Walker-Loud, A
2010-01-19
Low-energy baryon-baryon interactions are calculated in a high-statistics lattice QCD study on a single ensemble of anisotropic clover gauge-field configurations at a pion mass of m{sub {pi}} {approx} 390 MeV, a spatial volume of L{sup 3} {approx} (2.5 fm){sup 3}, and a spatial lattice spacing of b {approx} 0.123 fm. Luescher's method is used to extract nucleon-nucleon, hyperon-nucleon and hyperon-hyperon scattering phase shifts at one momentum from the one- and two-baryon ground-state energies in the lattice volume. The isospin-3/2 N{Sigma} interactions are found to be highly spin-dependent, and the interaction in the {sup 3}S{sub 1} channel is found to be strong. In contrast, the N{Lambda} interactions are found to be spin-independent, within the uncertainties of the calculation, consistent with the absence of one-pion-exchange. The only channel for which a negative energy-shift is found is {Lambda}{Lambda}, indicating that the {Lambda}{Lambda} interaction is attractive, as anticipated from model-dependent discussions regarding the H-dibaryon. The NN scattering lengths are found to be small, clearly indicating the absence of any fine-tuning in the NN-sector at this pion mass. This is consistent with our previous Lattice QCD calculation of NN interactions. The behavior of the signal-to-noise ratio in the baryon-baryon correlation functions, and in the ratio of correlation functions that yields the ground-state energy splitting is explored. In particular, focus is placed on the window of time slices for which the signal-to-noise ratio does not degrade exponentially, as this provides the opportunity to extract quantitative information about multi-baryon systems.
Baryons as Fock states of 3,5,... Quarks
Energy Technology Data Exchange (ETDEWEB)
Dmitri Diakonov; Victor Petrov
2004-09-01
We present a generating functional producing quark wave functions of all Fock states in the octet, decuplet and antidecuplet baryons in the mean field approximation, both in the rest and infinite momentum frames. In particular, for the usual octet and decuplet baryons we get the SU(6)-symmetric wave functions for their 3-quark component but with specific corrections from relativism and from additional quark-antiquark pairs. For the exotic antidecuplet baryons we obtain the 5-quark wave function.
Calculating Masses of Pentaquarks Composed of Baryons and Mesons
Directory of Open Access Journals (Sweden)
M. Monemzadeh
2016-01-01
Full Text Available We consider an exotic baryon (pentaquark as a bound state of two-body systems composed of a baryon (nucleon and a meson. We used a baryon-meson picture to reduce a complicated five-body problem to simple two-body problems. The homogeneous Lippmann-Schwinger integral equation is solved in configuration space by using one-pion exchange potential. We calculate the masses of pentaquarks θc(uuddc¯ and θb(uuddb¯.
Spectroscopy of singly, doubly, and triply bottom baryons
Wei, Ke-Wei; Liu, Na; Wang, Qian-Qian; Guo, Xin-Heng
2016-01-01
Recently, many singly bottom baryons have been established experimentally, but no doubly or triply bottom baryon has been observed. Under the Regge phenomenology, the mass of a ground state unobserved doubly or triply bottom baryon is expressed as a function of masses of the well established light baryons and singly bottom baryons. (For example, we write the mass of $\\Omega_{bbb}$ as a function of the masses of well established light baryons ($\\Sigma^{*}$, $\\Xi^{*}$, $\\Omega$) and singly bottom baryons ($\\Sigma_b^{*}$, $\\Xi_b^{*}$), and give its value to be 14788$\\pm$80 MeV.) After that, we calculate the values of Regge slopes and Regge intercepts for singly, doubly, and triply bottom baryons. (Regge intercepts and slopes, which are usually regarded as fundamental constants of hadron dynamics, are useful for many spectral and nonspectral purposes.) Then, masses of the orbitally excited singly, doubly, and triply bottom baryons are estimated. The isospin splitting is also determined, $M_{\\Xi_{bb}^{-}}-M_{\\Xi_{...
Hypermagnetic Fields and Baryon Asymmetry from Pseudoscalar Inflation
Anber, Mohamed M
2015-01-01
We show that maximally helical hypermagnetic fields produced during pseudoscalar inflation can generate the observed baryon asymmetry of the universe via the B+L anomaly in the Standard Model. We find that most of the parameter space of pseudoscalar inflation that explains the cosmological data leads to baryon overproduction, hence the models of natural inflation are severely constrained. We also point out a connection between the baryon number and topology of the relic magnetic fields. Both the magnitude and sign of magnetic helicity can be detected in future diffuse gamma ray data. This will be a smoking gun evidence for a link between inflation and the baryon asymmetry of the Universe.
Notes on exotic anti-decuplet of baryons
Polyakov, M V
2004-01-01
We emphasize the importance of identifying non-exotic SU(3) partners of the Theta^+ pentaquark, and indicate possible ways how to do it. We also use the soliton picture of baryons to relate Reggeon couplings of various baryons. These relations are used to estimate the Theta^+ production cross section in high energy processes. We show that the corresponding cross sections are significantly suppressed relative to the production cross sections of usual baryons. Finally, we present spin non-flip form factors of the anti-decuplet baryons in the framework of the chiral quark soliton model.
Magnetic Moments of Baryons with a Heavy Quark
Weigel, H
2003-01-01
We compute magnetic moments of baryons with a heavy quark in the bound state approach for heavy baryons. In this approach the heavy baryon is considered as a heavy meson bound to a light baryon. The latter is represented as a soliton excitation of light meson fields. We obtain the magnetic moments by sandwiching pertinent components of the electromagnetic current operator between the bound state wave--functions. We extract this current operator from the coupling to the photon field after extending the action to be gauge invariant.
Search for CP violation in baryon decays at LHCb
CERN. Geneva
2016-01-01
The phenomenon of CP violation has been observed in the K- and B-meson systems, but not yet with any baryonic particle. We report on searches for CP violation in baryon decays at LHCb using Run I data. We find evidence for CP violation in Lambda0b -> p pi- pi+ pi- decays with a statistical significance corresponding to 3.3 standard deviations, including systematic uncertainties. This represents the first evidence of CP violation in the baryon sector. An overview of other recent results of baryon decays will be presented, along with some highlights of the charmless B-decay programme.
Dark Matter in Lepto-Baryonic Left-Right Theories
Patra, Sudhanwa
2015-01-01
A Lepto-Baryonic Left-Right symmetric theory is considered where leptons and baryons are local gauge symmetries. These theories are generally anomalous and the possible gauge anomaly free solutions for these theories are presented here. This paper also shows different ways in which Lepto-Baryonic Left-Right theories are broken down to Standard Model gauge group which further breaks down to low energy by SM Higgs boson. It is found that the neutral component of fermion triplets can be a viable dark matter candidate originally introduced for gauge anomaly cancellation. The other dark matter possibilities within this Lepto-Baryonic Left-Right symmetric theories are also presented.
One-loop corrections to the baryon axial vector current
Indian Academy of Sciences (India)
M A Hernández-Ruíz
2012-10-01
The symmetry breaking corrections to the pion–baryon couplings vanish to first order in $1/N_{c}$, where $N_{c}$ is the number of colours. Loop graphs with octet and decuplet intermediate states cancel to various orders in $N_{c}$ as a consequence of the large-$N_{c}$ spin-flavour symmetry of QCD baryons. The baryon axial vector current is computed at one-loop order in heavy baryon chiral perturbation theory in the large Nc limit. $1/N_{c}$ corrections in the case of $g_{A}$ in QCD are presented here.
Quark-Pauli effects in three octet-baryons
Nakamoto, C
2016-01-01
To sustain a neutron star with about two times the solar mass, multi baryons including hyperons are expected to produce repulsive effects in the interior of its high baryon-density region. To examine possible quark-Pauli repulsion among the baryons, we solve the eigenvalue problem of the quark antisymmetrizer for three octet-baryons that are described by most compact spatial configurations. We find that the Pauli blocking effect is weak in the $\\Lambda nn$ system, while it is strong in the $\\Sigma^-nn$ system. The appearance of the $\\Sigma^-$ hyperon is suppressed in the neutron star interior but no quark-Pauli repulsion effectively works for the $\\Lambda$ hyperon.
Oscillation death in coupled oscillators
Institute of Scientific and Technical Information of China (English)
Wei ZOU; Xin-gang WANG; Qi ZHAO; Meng ZHAN
2009-01-01
We study dynamical behaviors in coupled nonlinear oscillators and find that under certain condi- tions, a whole coupled oscillator system can cease oscil- lation and transfer to a globally nonuniform stationary state [I.e., the so-called oscillation death (OD) state], and this phenomenon can be generally observed. This OD state depends on coupling strengths and is clearly differ- ent from previously studied amplitude death (AD) state, which refers to the phenomenon where the whole system is trapped into homogeneously steady state of a fixed point, which already exists but is unstable in the ab- sence of coupling. For larger systems, very rich pattern structures of global death states are observed. These Turing-like patterns may share some essential features with the classical Turing pattern.
Search for doubly charmed baryons and study of charmed strange baryons at Belle
Kato, Y; Adachi, I; Aihara, H; Asner, D M; Aushev, T; Bakich, A M; Bala, A; Ban, Y; Bhardwaj, V; Bhuyan, B; Bobrov, A; Bonvicini, G; Bozek, A; Bračko, M; Browder, T E; Červenkov, D; Chekelian, V; Chen, A; Cheon, B G; Chilikin, K; Chistov, R; Cho, K; Chobanova, V; Choi, Y; Cinabro, D; Dalseno, J; Danilov, M; Doležal, Z; Drásal, Z; Drutskoy, A; Dutta, D; Dutta, K; Eidelman, S; Farhat, H; Fast, J E; Ferber, T; Gaur, V; Gabyshev, N; Ganguly, S; Garmash, A; Gillard, R; Goh, Y M; Golob, B; Haba, J; Hayasaka, K; Hayashii, H; He, X H; Horii, Y; Hoshi, Y; Hou, W -S; Hsiung, Y B; Inami, K; Ishikawa, A; Iwasaki, Y; Iwashita, T; Jaegle, I; Julius, T; Kang, J H; Kato, E; Kawasaki, T; Kiesling, C; Kim, D Y; Kim, H J; Kim, J B; Kim, J H; Kim, M J; Kim, Y J; Klucar, J; Ko, B R; Kodyš, P; Korpar, S; Krokovny, P; Kuhr, T; Kuzmin, A; Kwon, Y -J; Lee, S -H; Li, J; Li, Y; Gioi, L Li; Libby, J; Liu, Y; Liventsev, D; Matvienko, D; Miyabayashi, K; Miyata, H; Mizuk, R; Moll, A; Muramatsu, N; Mussa, R; Nagasaka, Y; Nakano, E; Nakao, M; Nayak, M; Nedelkovska, E; Ng, C; Niiyama, M; Nisar, N K; Nishida, S; Nitoh, O; Ogawa, S; Okuno, S; Pakhlov, P; Pakhlova, G; Park, C W; Park, H; Park, H K; Pedlar, T K; Peng, T; Pestotnik, R; Petrič, M; Piilonen, L E; Ritter, M; Röhrken, M; Rostomyan, A; Sahoo, H; Saito, T; Sakai, Y; Sandilya, S; Santelj, L; Sanuki, T; Savinov, V; Schneider, O; Schnell, G; Schwanda, C; Semmler, D; Senyo, K; Seon, O; Shapkin, M; Shen, C P; Shibata, T -A; Shiu, J -G; Shwartz, B; Sibidanov, A; Sohn, Y -S; Sokolov, A; Solovieva, E; Stanič, S; Starič, M; Steder, M; Sumihama, M; Sumiyoshi, T; Tamponi, U; Tanida, K; Tatishvili, G; Teramoto, Y; Uchida, M; Uehara, S; Uglov, T; Unno, Y; Uno, S; Van Hulse, C; Vanhoefer, P; Varner, G; Vinokurova, A; Vorobyev, V; Wagner, M N; Wang, C H; Wang, M -Z; Wang, P; Watanabe, M; Watanabe, Y; Williams, K M; Won, E; Yamashita, Y; Yashchenko, S; Zhang, Z P; Zhilich, V; Zhulanov, V; Zupanc, A
2013-01-01
We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb^-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We search for doubly charmed baryons Xi_cc^+(+) with the Lambda_c^+K^-pi^+(pi^+) and Xi_c^0pi^+(pi^+) final states. No significant signal is observed. We also search for two excited charmed strange baryons, Xi_c(3055)^+ and Xi_c(3123)^+ with the Sigma_c^++(2455)K^- and Sigma_c^++(2520)K^- final states. The Xi_c(3055)^+ signal is observed with a significance of 6.6 standard deviations including systematic uncertainty, while no signature of the Xi_c(3123)^+ is seen. We also study properties of the Xi_c(2645)^+ and measure a width of 2.6 +- 0.2 (stat) +- 0.4 (syst) MeV/c^2, which is the first significant determination.
Papastergis, Emmanouil; Cattaneo, Andrea; Huang, Shan; Giovanelli, Riccardo; Haynes, Martha P.
2012-01-01
We use both an HI-selected and an optically-selected galaxy sample to directly measure the abundance of galaxies as a function of their "baryonic" mass (stars + atomic gas). Stellar masses are calculated based on optical data from the Sloan Digital Sky Survey (SDSS) and atomic gas masses are calcula
a Relativistic Calculation of Baryon Masses
Giammarco, Joseph Michael
1990-01-01
We calculate ground state baryon masses using a saddle-point variational (SPV) method, which permits us the use of fully relativistic 4-component Dirac spinors without the need for positive energy projection operators. This variational approach has been shown to work in the relativistic domain for one particle in an external potential (Dirac equation). We have extended its use to the relativistic 3-body Breit equation. Our procedure is as follows: we pick a trial wave function having the appropriate spin, flavor and color dependence. This can be accomplished with a non-symmetric relativistic spatial wave function having two different size parameters if the the first two quarks are always chosen to be identical. We than calculate an energy eigenvalue for the particle state and vary the parameters in our wave function to search for a "saddle-point". We minimize the energy with respect to the two size parameters and maximize with respect to two parameters that measure the contribution from the negative-energy states. This gives the baryon's mass as a function of four input parameters: the masses of the up, down and strange quarks (m_{u=d },m_{s}), and the strength of the coupling constants for the potentials ( alpha_{s},mu). We do this for the eight Baryon ground states and fit these to experimental data. This fit gives the values of the input parameters. For the potentials we use a coulombic term to represent one-gluon exchange and a linear term for confinement. For both terms we include a retardation term required by relativity. We also add delta function and spin-spin terms to account for the large contribution of the coulomb interaction at the origin. The results we obtain from our SPV method are in good agreement with experimental data. The actual search for the saddle-point parameters and the fitting of the quark masses and the values of the coupling strengths was done on a CDC Cyber 860.
Magnetic Bloch oscillations in nanowire superlattice rings.
Citrin, D S
2004-05-14
The recent growth of semiconductor nanowire superlattices encourages hope that Bloch-like oscillations in such structures formed into rings may soon be observed in the presence of a time-dependent magnetic flux threading the ring. These magnetic Bloch oscillations are a consequence of Faraday's law; the time-dependent flux produces an electromotive force around the ring, thus leading to the Bloch-like oscillations. In the spectroscopic domain, generalized Wannier-Stark states are found that are manifestations of the emf-induced localization of the states.
Non-baryonic dark matter in cosmology
Del Popolo, A.
2013-07-01
This paper is based on lectures given at the IX Mexican School on Gravitation and Mathematical Physics. The lectures (as the paper) were a broad-band review of the current status of non-baryonic dark matter research. I start with a historical overview of the evidences of dark matter existence, then I discuss how dark matter is distributed from small scale to large scale, and I then verge the attention to dark matter nature: dark matter candidates and their detection. I finally discuss some of the limits of the ΛCDM model, with particular emphasis on the small scale problems of the paradigm.
SU(3) flavour breaking and baryon structure
Energy Technology Data Exchange (ETDEWEB)
Cooke, A.N.; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo (Japan); Pleiter, D. [Forschungszentrum Juelich GmbH (Germany). Juelich Supercomputing Centre (JSC); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Shanahan, P.; Zanotti, J.M. [Adelaide Univ., SA (Australia). CSSM, School of Chemistry and Physics; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Collaboration: QCDSF/UKQCD Collaboration
2013-11-15
We present results from the QCDSF/UKQCD collaboration for hyperon electromagnetic form factors and axial charges obtained from simulations using N{sub f}=2+1 flavours of O(a)-improved Wilson fermions. We also consider matrix elements relevant for hyperon semileptonic decays. We find flavour-breaking effects in hyperon magnetic moments which are consistent with experiment, while our results for the connected quark spin content indicates that quarks contribute more to the spin of the {Xi} baryon than they do to the proton.
Baryon instability search in large detectors
Energy Technology Data Exchange (ETDEWEB)
Moscoso, L. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee
1996-08-01
Nucleon decay appears as a consequence of models trying to explain the baryon-antibaryon asymmetry. This has motivated 15 years ago many underground experiments devoted to the search of proton and neutron decay. A very large number of decay channels have been investigated and no evidence has been found yielding lower limits on lifetime which rule out the minimal SU(5) Grand Unified Theory predictions and put severe constraints on more complicated models. Next generation experiments like Super-Kamiokande, which is starting to take data now, ICARUS, whose a 600 ton prototype is under construction, will be sensitive to more complicated models predicting larger lifetimes. (author). 16 refs.
Magnetic Polarizability of Diquarks in Baryons
Filip, Peter
2014-01-01
We study the response of diquark wave function in \\Lambda-type baryons to strong magnetic fields. It is found that quantum state of J=0 diquark (ud) in the magnetic field changes due to magnetic polarizability, and constituent quarks in (ud) diquark become polarized. The phenomenon influences polarized quark distribution functions \\Delta u(x) and \\Delta d(x), which therefore may be sensitive to the internal electromagnetic fields in hypernuclei. We also speculate, that strange quark polarization in nucleon may originate from the interaction of virtual (ss') quark pairs with the intrinsic magnetic field of nucleon B $\\approx$ 10^13 T.
Baryons in Massive Gross-Neveu Models
Thies, M; Thies, Michael; Urlichs, Konrad
2005-01-01
Baryons in the large N limit of (1+1)-dimensional Gross-Neveu models with either discrete or continuous chiral symmetry have long been known. We generalize their construction to the case where the symmetry is explicitly broken by a bare mass term in the Lagrangian. In the discrete symmetry case, the exact solution is found for arbitrary bare fermion mass, using the Hartree-Fock approach. In the continuous symmetry case, a derivative expansion allows us to rederive a formerly proposed Skyrme-type model and to compute systematically corrections to the leading order description based on an effective sine-Gordon theory.
Non-Baryonic Dark Matter in Cosmology
Del Popolo, A
2014-01-01
This paper is a broad-band review of the current status of non-baryonic dark matter research. I start with a historical overview of the evidences of dark matter existence, then I discuss how dark matter is distributed from small scale to large scale, and I then verge the attention to dark matter nature: dark matter candidates and their detection. I finally discuss some of the limits of the $\\Lambda$CDM model, with particular emphasis on the small scale problems of the paradigm.
High Statistics Analysis using Anisotropic Clover Lattices: (III) Baryon-Baryon Interactions
Energy Technology Data Exchange (ETDEWEB)
Beane, Silas [Univ. of New Hampshire, Durham, NH (United States); Detmold, William [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lin, Huey-Wen [Univ. of Washington, Seattle, WA (United States); Luu, Thomas C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Orginos, Kostas [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Savage, Martin [Univ. of Washington, Seattle, WA (United States); Torok, Aaron M. [Indiana Univ., Bloomington, IN (United States). Dept. of Physics; Walker-Loud, Andre [College of William and Mary, Williamsburg, VA (United States)
2010-03-01
Low-energy baryon-baryon interactions are calculated in a high-statistics lattice QCD study on a single ensemble of anisotropic clover gauge-field configurations at a pion mass of m_pi ~ 390 MeV, a spatial volume of L^3 ~ (2.5 fm)^3, and a spatial lattice spacing of b ~ 0.123 fm. Luscher’s method is used to extract nucleon-nucleon, hyperon-nucleon and hyperon-hyperon scattering phase shifts at one momentum from the one- and two-baryon ground-state energies in the lattice volume. The N-Sigma interactions are found to be highly spin-dependent, and the interaction in the ^3 S _1 channel is found to be strong. In contrast, the N-Lambda interactions are found to be spin-independent, within the uncertainties of the calculation, consistent with the absence of one-pion-exchange. The only channel for which a negative energy-shift is found is Lambda-Lambda, indicating that the Lambda-Lambda interaction is attractive, as anticipated from model-dependent discussions regarding the H-dibaryon. The NN scattering lengths are found to be small, clearly indicating the absence of any fine-tuning in the NN-sector at this pion mass. This is consistent with our previous Lattice QCD calculation of the NN interactions. The behavior of the signal-to-noise ratio in the baryon-baryon correlation functions, and in the ratio of correlation functions that yields the ground-state energy splitting
Baryon octet distribution amplitudes in Wandzura-Wilczek approximation
Energy Technology Data Exchange (ETDEWEB)
Anikin, I.V. [Joint Institute of Nuclear Research, Moscow (Russian Federation). Bogoliubov Lab. of Theoretical Physics; Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Manashov, A.N. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2015-12-15
We study higher twist distribution amplitudes for the SU{sub F}(3) baryon octet. We identify independent functions for all baryons in the isospin symmetry limit and calculate the Wandzura-Wilczek contributions to the twist-4 and 5 distributions amplitudes.
Baryon magnetic moments in the effective quark Lagrangian approach
Simonov, YA; Tjon, JA; Weda, J; Simonov, Yu A.
2002-01-01
An effective quark Lagrangian is derived from first principles through bilocal gluon field correlators. It is used to write down equations for baryons, containing both perturbative and nonperturbative fields. As a result one obtains magnetic moments of octet and decuplet baryons without the introduc
Evidence for chiral logarithms in the baryon spectrum
Walker-Loud, Andre
2011-01-01
Using precise lattice QCD computations of the baryon spectrum, we present the first direct evidence for the presence of contributions to the baryon masses which are non-analytic in the light quark masses; contributions which are often denoted "chiral logarithms". We isolate the poor convergence of SU(3) baryon chiral perturbation theory to the flavor-singlet mass combination. The flavor-octet baryon mass splittings, which are corrected by chiral logarithms at next to leading order in SU(3) chiral perturbation theory, yield baryon-pion axial coupling constants D, F, C and H consistent with QCD values; the first evidence of chiral logarithms in the baryon spectrum. The Gell-Mann--Okubo relation, a flavor-27 baryon mass splitting, which is dominated by chiral corrections from light quark masses, provides further evidence for the presence of non-analytic light quark mass dependence in the baryon spectrum; we simultaneously find the GMO relation to be inconsistent with the first few terms in a taylor expansion in ...
(Hybrid) Baryons in the Flux-Tube Model
Page, P R
1999-01-01
We construct baryons and hybrid baryons in the non-relativistic flux-tube model of Isgur and Paton. The motion of the flux-tube with the three quark positions fixed, except for centre of mass corrections, is discussed. It is shown that the problem can to an excellent approximation be reduced to the independent motion of a junction and strings.
Finite Volume Effect of Baryons in Strange Hadronic Matter
Institute of Scientific and Technical Information of China (English)
SUN Bao-Xi; LI Lei; NING Ping-Zhi; ZHAO En-Guang
2001-01-01
The finite volume effect of baryons in strange hadronic matter (SHM) is studied within the framework of relativistic mean-field theory. As this effect is concerned, the saturation density of SHM turns lower, and the binding energy per baryon decreases. Its influence to the compression modulus of SHM is also discussed.
Directory of Open Access Journals (Sweden)
G. Bellini
2014-01-01
Full Text Available In the last decades, a very important breakthrough has been brought about in the elementary particle physics by the discovery of the phenomenon of the neutrino oscillations, which has shown neutrino properties beyond the Standard Model. But a full understanding of the various aspects of the neutrino oscillations is far to be achieved. In this paper the theoretical background of the neutrino oscillation phenomenon is described, referring in particular to the paradigmatic models. Then the various techniques and detectors which studied neutrinos from different sources are discussed, starting from the pioneering ones up to the detectors still in operation and to those in preparation. The physics results are finally presented adopting the same research path which has been crossed by this long saga. The problems not yet fixed in this field are discussed, together with the perspectives of their solutions in the near future.
Baryon masses with dynamical twisted mass fermions
Alexandrou, C; Koutsou, G; Baron, R; Guichon, P; Brinet, M; Carbonell, J; Drach, V; Liu, Z; Pène, O; Urbach, C
2007-01-01
We present results on the mass of the nucleon and the $\\Delta$ using two dynamical degenerate twisted mass quarks. The evaluation is performed at four quark masses corresponding to a pion mass in the range of 690-300 MeV on lattices of size 2.1 fm and 2.7 fm. We check for cutoff effects by evaluating these baryon masses on lattices of spatial size 2.1 fm with lattice spacings $a(\\beta=3.9)=0.0855(6)$ fm and $a(\\beta=4.05)=0.0666(6)$ fm, determined from the pion sector and find them to be within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. The nucleon mass at the physical point provides a determination of the lattice spacing. Using heavy baryon chiral perturbation theory at ${\\cal O}(p^3)$ we find $a(\\beta=3.9)=0.0879(12)$ fm, with a systematic error due to the chiral extrapolation estimated to be about the same as the statistical error. This value of the lattice spacing is in good agreement with the value determined from the pion se...
The Compressed Baryonic Matter Experiment at FAIR
Energy Technology Data Exchange (ETDEWEB)
Heuser, Johann M.
2013-05-02
The Compressed Baryonic Matter (CBM) experiment will explore the phase diagram of strongly interacting matter in the region of high net baryon densities. The experiment is being laid out for nuclear collision rates from 0.1 to 10 MHz to access a unique wide spectrum of probes, including rarest particles like hadrons containing charm quarks, or multi-strange hyperons. The physics programme will be performed with ion beams of energies up to 45 GeV/nucleon. Those will be delivered by the SIS-300 synchrotron at the completed FAIR accelerator complex. Parts of the research programme can already be addressed with the SIS-100 synchrotron at the start of FAIR operation in 2018. The initial energy range of up to 11 GeV/nucleon for heavy nuclei, 14 GeV/nucleon for light nuclei, and 29 GeV for protons, allows addressing the equation of state of compressed nuclear matter, the properties of hadrons in a dense medium, the production and propagation of charm near the production threshold, and exploring the third, strange dimension of the nuclide chart. In this article we summarize the CBM physics programme, the preparation of the detector, and give an outline of the recently begun construction of the Facility for Antiproton and Ion Research.
Predictions for masses of bottom baryons
Karliner, Marek; Lipkin, Harry J; Rosner, Jonathan L
2007-01-01
The recent observation of Sigma_b^{+-} (uub and ddb) and Xi_b^- (dsb) baryons at the Tevatron within 2 MeV of our theoretical predictions provides a strong motivation for applying the same theoretical approach, based on modeling the color hyperfine interaction, to predict the masses of other bottom baryons which might be observed in the foreseeable future. For S-wave qqb states we predict M(Omega_b) = 6052.1+-5.6 MeV, M(Omega^*_b) = 6082.8+-5.6 MeV, and M(Xi_b^0) = 5786.7 +- 3.0 MeV. For states with one unit of orbital angular momentum between the b quark and the two light quarks we predict M(Lambda_{b[1/2]}) = 5929+-2 MeV, M(Lambda_{b[3/2]}) = 5940+-2 MeV, M(Xi_{b[1/2]}) = 6106+-4 MeV, and M(Xi_{b[3/2]}) = 6115+-4 MeV.
The Quark Model and $b$ Baryons
Karliner, Marek; Lipkin, Harry J; Rosner, Jonathan L
2008-01-01
The recent observation at the Tevatron of $\\Sigma_b^{\\pm}$ ($uub$ and $ddb$) baryons within 2 MeV of the predicted $\\Sigma_b - \\Lambda_b$ splitting and of $\\Xi_b^-$ $(dsb)$ baryons at the Tevatron within a few MeV of predictions has provided strong confirmation for a theoretical approach based on modeling the color hyperfine interaction. The prediction of $M(\\Xi^-_b) = 5790$ to 5800 MeV is reviewed and similar methods used to predict the masses of the excited states $\\Xi_b^\\prime$ and $\\Xi_b^*$. The main source of uncertainty is the method used to estimate the mass difference $m_b - m_c$ from known hadrons. We verify that corrections due to the details of the interquark potential and to $\\Xi_b$--$\\Xi_b^\\prime$ mixing are small. For S-wave $qqb$ states we predict $M(\\Omega_b) = 6052.1 \\pm 5.6$ MeV, $M(\\Omega^*_b) = 6082.8 \\pm 5.6$ MeV, and $M(\\Xi_b^0) = 5786.7 \\pm 3.0$ MeV. For states with one unit of orbital angular momentum between the $b$ quark and the two light quarks we predict $M(\\Lambda_{b[1/2]}) = 5929...
Electroproduction of Baryon Resonances and Strangeness Suppression
Santopinto, E; Tecocoatzi, H Garcia
2016-01-01
We describe the electroproduction ratios of baryon-meson states from nucleon using an extension of the quark model that takes into account the sea. As a result we provide, with no adjustable parameters, the predictions of ratios of exclusive meson-baryon final states: Lambda K , Sigma K, p pion, and n pion. These predictions are in agreement with the new Jlab experimental data showing that sea quarks play an important role in the electroproduction. We also predicted further ratios of exclusive reactions that can be measured and tested in future experiments. In particular, we suggested new experiments on deuterium and tritium. Such measurements can provide crucial test of different predictions concerning the structure of nucleon and its sea quarks helping to solve an outstanding problem. Finally, we computed the so called strangeness suppression factor, lambda s, that is the suppression of strange quark-antiquarks compared to nonstrange pairs, and we found that our finding with this simple extension of the qua...
Nayfeh, Ali Hasan
1995-01-01
Nonlinear Oscillations is a self-contained and thorough treatment of the vigorous research that has occurred in nonlinear mechanics since 1970. The book begins with fundamental concepts and techniques of analysis and progresses through recent developments and provides an overview that abstracts and introduces main nonlinear phenomena. It treats systems having a single degree of freedom, introducing basic concepts and analytical methods, and extends concepts and methods to systems having degrees of freedom. Most of this material cannot be found in any other text. Nonlinear Oscillations uses sim
Freire, Joana G.; Cabeza, Cecilia; Marti, Arturo; Pöschel, Thorsten; Gallas, Jason A. C.
2013-06-01
The investigation of regular and irregular patterns in nonlinear oscillators is an outstanding problem in physics and in all natural sciences. In general, regularity is understood as tantamount to periodicity. However, there is now a flurry of works proving the existence of ``antiperiodicity'', an unfamiliar type of regularity. Here we report the experimental observation and numerical corroboration of antiperiodic oscillations. In contrast to the isolated solutions presently known, we report infinite hierarchies of antiperiodic waveforms that can be tuned continuously and that form wide spiral-shaped stability phases in the control parameter plane. The waveform complexity increases towards the focal point common to all spirals, a key hub interconnecting them all.
Baryon formation and dissociation in dense hadronic and quark matter
Energy Technology Data Exchange (ETDEWEB)
Wang Jincheng [Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Anhui 230026 (China); Institute for Theoretical Physics, Johann Wolfgang Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Wang Qun, E-mail: qunwang@ustc.edu.cn [Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Anhui 230026 (China); Theoretical Physics Center for Science Facilities, Chinese Academy of Sciences, Beijing 100049 (China); Rischke, Dirk H. [Institute for Theoretical Physics, Johann Wolfgang Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany)
2011-10-19
We study the formation of baryons as composed of quarks and diquarks in hot and dense hadronic matter in a Nambu-Jona-Lasinio (NJL)-type model. We first solve the Dyson-Schwinger equation for the diquark propagator and then use this to solve the Dyson-Schwinger equation for the baryon propagator. We find that stable baryon resonances exist only in the phase of broken chiral symmetry. In the chirally symmetric phase, we do not find a pole in the baryon propagator. In the color-superconducting phase, there is a pole, but it has a large decay width. The diquark does not need to be stable in order to form a stable baryon, a feature typical for so-called Borromean states. Varying the strength of the diquark coupling constant, we also find similarities to the properties of an Efimov state.
Doubly heavy baryon spectra guided by lattice QCD
Garcilazo, H; Vijande, J
2016-01-01
This paper provides results for the ground state and excited spectra of three-flavored doubly heavy baryons, $bcn$ and $bcs$. We take advantage of the spin-independent interaction recently obtained to reconcile the lattice SU(3) QCD static potential and the results of nonperturbative lattice QCD for the triply heavy baryon spectra. We show that the spin-dependent potential might be constrained on the basis of nonperturbative lattice QCD results for the spin splittings of three-flavored doubly heavy baryons. Our results may also represent a challenge for future lattice QCD work, because a smaller lattice error could help in distinguishing between different prescriptions for the spin-dependent part of the interaction. Thus, by comparing with the reported baryon spectra obtained with parameters estimated from lattice QCD, one can challenge the precision of lattice calculations. The present work supports a coherent description of singly, doubly and triply heavy baryons with the same Cornell-like interacting poten...
Spectrum of heavy baryons in the quark model
Yoshida, Tetsuya; Hosaka, Atsushi; Oka, Makoto; Sadato, Katsunori
2015-01-01
Single- and double- heavy baryons are studied in the constituent quark model. The model Hamiltonian is chosen as a standard one with two exceptions : (1) The color-Coulomb term depend on quark masses, and (2) an antisymmetric $LS$ force is introduced. Model parameters are fixed by the strange baryon spectra, $\\Lambda$ and $\\Sigma$ baryons. The masses of the observed charmed and bottomed baryons are, then, fairly well reproduced. Our focus is on the low-lying negative-parity states, in which the heavy baryons show specific excitation modes reflecting the mass differences of heavy and light quarks. By changing quark masses from the SU(3) limit to the strange quark mass, further to the charm and bottom quark masses, we demonstrate that the spectra change from the SU(3) symmetry patterns to the heavy quark symmetry ones.
Octet Baryon Electromagnetic Form Factors in a Relativistic Quark Model
Energy Technology Data Exchange (ETDEWEB)
Gilberto Ramalho, Kazuo Tsushima
2011-09-01
We study the octet baryon electromagnetic properties by applying the covariant spectator quark model, and provide covariant parametrization that can be used to study baryon electromagnetic reactions. While we use the lattice QCD data in the large pion mass regime (small pion cloud effects) to determine the parameters of the model in the valence quark sector, we use the nucleon physical and octet baryon magnetic moment data to parameterize the pion cloud contributions. The valence quark contributions for the octet baryon electromagnetic form factors are estimated by extrapolating the lattice parametrization in the large pion mass regime to the physical regime. As for the pion cloud contributions, we parameterize them in a covariant, phenomenological manner, combined with SU(3) symmetry. We also discuss the impact of the pion cloud effects on the octet baryon electromagnetic form factors and their radii.
Octet baryon electromagnetic form factors in a relativistic quark model
Ramalho, G
2011-01-01
We study the octet baryon electromagnetic properties by applying the covariant spectator quark model, and provide covariant parametrization that can be used to study baryon electromagnetic reactions. While we use the lattice QCD data in the large pion mass regime (small pion cloud effects) to determine the parameters of the model in the valence quark sector, we use the nucleon physical and octet baryon magnetic moment data to parameterize the pion cloud contributions. The valence quark contributions for the octet baryon electromagnetic form factors are estimated by extrapolating the lattice parametrization in the large pion mass regime to the physical regime. As for the pion cloud contributions, we parameterize them in a covariant, phenomenological manner, combined with SU(3) symmetry. We also discuss the impact of the pion cloud effects on the octet baryon electromagnetic form factors and their radii.
Strange baryon spectroscopy in the relativistic quark model
Faustov, R N
2015-01-01
Mass spectra of strange baryons are calculated in the framework of the relativistic quark model based on the quasipotential approach. Baryons are treated as the relativistic quark-diquark bound systems. It is assumed that two quarks with equal constituent masses form a diquark. The diquark excitations and its internal structure are consistently taken into account. Calculations are performed up to rather high orbital and radial excitations of strange baryons. On this basis the Regge trajectories are constructed. The obtained results are compared with available experimental data and previous predictions. It is found that all masses of the 4- and 3-star, as well as most of the 2- and 1-star states of strange baryons with established quantum numbers are well reproduced. The developed relativistic quark-diquark model predicts less excited states than three-quark models of strange baryons.
Strange baryon spectroscopy in the relativistic quark model
Faustov, R. N.; Galkin, V. O.
2015-09-01
Mass spectra of strange baryons are calculated in the framework of the relativistic quark model based on the quasipotential approach. Baryons are treated as relativistic quark-diquark bound systems. It is assumed that two quarks with equal constituent masses form a diquark. The diquark excitations and its internal structure are consistently taken into account. Calculations are performed up to rather high orbital and radial excitations of strange baryons. On this basis the Regge trajectories are constructed. The obtained results are compared with available experimental data and previous predictions. It is found that all masses of the 4- and 3-star states of strange baryons with established quantum numbers, as well as most of the 2- and 1-star states, are well reproduced. The developed relativistic quark-diquark model predicts less excited states than three-quark models of strange baryons.
A new high sensitivity search for neutron-antineutron oscillations at the ESS
Milstead, David
2015-01-01
A sensitive search for neutron-antineutron oscillations can provide a unique probe of some of the central questions in particle physics and cosmology: the energy scale and mechanism for baryon number violation, the origin of the baryon-antibaryon asymmetry of the universe, and the mechanism for neutrino mass generation. A remarkable opportunity has emerged to search for such oscillations with the construction of the European Spallation Source (ESS). A collaboration has been formed which has proposed a search at the ESS, which would provide a sensitivity to the oscillation probability which is three orders of magnitude greater than that achieved at an ILL experiment at which the present best limit on free neutron-antineutron oscillations was obtained.
Aspects of baryon structure in lattice QCD
Babich, Ronald
Despite the long success of Quantum Chromodynamics (QCD) as the theory of the strong interactions, there remains much to be understood about the structure of hadrons and the consequences of QCD in the nonperturbative regime. Lattice gauge theory, a framework nearly as old as QCD itself, makes calculations in this regime possible, starting from first principles. With advances in theoretical understanding, methods, and computer technology, the lattice has found application to an ever-widening range of problems. In this dissertation, I consider two such problems having to do with the structure of baryons. The first concerns the contribution of sea quarks, and the strange quark in particular, to form factors of the nucleon. This has been a long-standing challenge for the lattice, because such contributions involve the insertion of a current on a quark loop, demanding the full inversion of the discretized Dirac operator, conceptually a large sparse matrix. I discuss methods for addressing this challenge and present a calculation of the strange scalar form factor and the related parameter fTs. The latter is of great theoretical interest, since it enters into the cross section for the scattering of dark matter off nuclei in supersymmetric extensions of the standard model. As such, it represents a major uncertainty in the interpretation of direct detection experiments. I also present results for the strange quark contribution to the nucleon's axial and electromagnetic form factors, which are themselves the subject of active experimental programs. These calculations were performed using the Wilson fermion formulation on a 243 x 64 anisotropic lattice. In the second part of the dissertation, I turn to the valence sector and address the role of diquark correlations in the observed spectrum of hadrons and their properties. A diquark is a correlated pair of quarks, thought to play an important role in certain phenomenological models of hadrons. I present results for baryon wave
Hyperon Single-Particle Potentials Calculated from SU6 Quark-Model Baryon-Baryon Interactions
Kohno, M; Fujita, T; Nakamoto, C; Suzuki, Y
2000-01-01
Using the SU6 quark-model baryon-baryon interaction recently developed by the Kyoto-Niigata group, we calculate NN, Lambda N and Sigma N G-matrices in ordinary nuclear matter. This is the first attempt to discuss the Lambda and Sigma single-particle potentials in nuclear medium, based on the realistic quark-model potential. The Lambda potential has the depth of more than 40 MeV, which is more attractive than the value expected from the experimental data of Lambda-hypernuclei. The Sigma potential turns out to be repulsive, the origin of which is traced back to the strong Pauli repulsion in the Sigma N (I=3/2) ^3S_1 state.
XRASE: The X-Ray Spectroscopic Explorer
DEFF Research Database (Denmark)
Schnopper, H.W.; Silver, E.; Murray, S.
2001-01-01
The X-Ray Spectroscopic Explorer (XRASE) has a unique combination of features that will make it possible to address many of NASA's scientific goals. These include how galaxy clusters form, the physics and chemistry of the ISM, the heating of stellar coronae, the amount and content of intergalactic...... baryonic matter, the mass of black holes and the formation of disks and jets in AGN and galactic binaries. XRASE has a thin foil, multilayered telescope with a large collecting area up to 10 keV, especially in the Fe K alpha region (1100 cm(2)). Its microcalorimeter array combines high energy resolution (7...... eV at 6 keV) and efficiency with a field-of-view of 26 arcmin(2) . A deep orbit allows for long, continuous observations. Monitoring instruments in the optical (WOM-X), UV (TAUVEX) and hard X-RAY (GRAM) bands will offer exceptional opportunities to make simultaneous multi-wavelength observations....
Quark-Model Baryon-Baryon Interaction and its Applications to Hypernuclei
Fujiwara, Y; Suzuki, Y; Kohno, M; Miyagawa, K
2004-01-01
The quark-model baryon-baryon interaction fss2, proposed by the Kyoto-Niigata group, is a unified model for the complete baryon octet (B_8=N, Lambda, Sigma and Xi), which is formulated in a framework of the (3q)-(3q) resonating-group method (RGM) using the spin-flavor SU_6 quark-model wave functions and effective meson-exchange potentials at the quark level. Model parameters are determined to reproduce properties of the nucleon-nucleon system and the low-energy cross section data for the hyperon-nucleon scattering. Due to the several improvements including the introduction of vector-meson exchange potentials, fss2 has achieved very accurate description of the NN and YN interactions, comparable to various one-boson exchange potentials. We review the essential features of fss2 and our previous model FSS, and their predictions to few-body systems in confrontation with the available experimental data. Some characteristic features of the B_8 B_8 interactions with the higher strangeness, S=-2, -3, -4, predicted by ...
Mirage in Temporal Correlation functions for Baryon-Baryon Interactions in Lattice QCD
Iritani, Takumi; Aoki, Sinya; Gongyo, Shinya; Hatsuda, Tetsuo; Ikeda, Yoichi; Inoue, Takashi; Ishii, Noriyoshi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji
2016-01-01
Single state saturation of the temporal correlation function is a key condition to extract physical observables such as energies and matrix elements of hadrons from lattice QCD simulations. A method commonly employed to check the saturation is to seek for a plateau of the observables for large Euclidean time. Identifying the plateau in the cases having nearby states, however, is non-trivial and one may even be misled by a fake plateau. Such a situation takes place typically for the system with two or more baryons. In this study, we demonstrate explicitly the danger from a possible fake plateau in the temporal correlation functions mainly for two baryons ($\\Xi\\Xi$ and $NN$), and three and four baryons ($^3{\\rm He}$ and $^4{\\rm He})$ as well, employing (2+1)-flavor lattice QCD at $m_{\\pi}=0.51$ GeV on four lattice volumes with $L=$ 2.9, 3.6, 4.3 and 5.8 fm. Caution is given for drawing conclusion on the bound $NN$, $3N$ and $4N$ systems only based on the temporal correlation functions.
Baryon transition form factors at the pole
Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.
2016-12-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the GM, GE, and GC form factors for the Δ (1232 ) resonance excitation at the Breit-Wigner resonance and pole positions up to Q2=5 GeV2 . We also explore the E /M and S /M ratios as functions of Q2. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Baryon transition form factors at the pole
Tiator, L; Workman, R L; Hadžimehmedović, M; Osmanović, H; Omerović, R; Stahov, J; Švarc, A
2016-01-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the $G_M$, $G_E$, and $G_C$ form factors for the $\\Delta(1232)$ resonance excitation at the Breit-Wigner resonance and pole positions up to $Q^2=5$ GeV$^2$. We also explore the $E/M$ and $S/M$ ratios as functions of $Q^2$. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Cluster outskirts and the missing baryons
Eckert, D.
2016-06-01
Galaxy clusters are located at the crossroads of intergalactic filaments and are still forming through the continuous merging and accretion of smaller structures from the surrounding cosmic web. Deep, wide-field X-ray studies of the outskirts of the most massive clusters bring us valuable insight into the processes leading to the growth of cosmic structures. In addition, cluster outskirts are privileged sites to search for the missing baryons, which are thought to reside within the filaments of the cosmic web. I will present the XMM cluster outskirts project, a VLP that aims at mapping the outskirts of 13 nearby clusters. Based on the results obtained with this program, I will then explore ideas to exploit the capabilities of XMM during the next decade.
Quark-mass dependence of baryon resonances
Energy Technology Data Exchange (ETDEWEB)
Lutz, M.F.M. [Gesellschaft fuer Schwerionenforschung (GSI), Planck Str. 1, D-64291 Darmstadt (Germany) and Institut fuer Kernphysik, TU Darmstadt, D-64289 Darmstadt (Germany)]. E-mail: m.lutz@gsi.de; Garcia-Recio, C. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain); Kolomeitsev, E.E. [Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen (Denmark); Nieves, J. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)
2005-05-30
We study the quark-mass dependence of JP=12- s-wave and JP=32- d-wave baryon resonances. Parameter-free results are obtained in terms of the leading order chiral Lagrangian. In the 'heavy' SU(3) limit with m{pi}=mK{approx}500 MeV the s-wave resonances turn into bound states forming two octets plus a singlet representations of the SU(3) group. Similarly the d-wave resonances turn into bound states forming an octet and a decuplet in this limit. A contrasted result is obtained in the 'light' SU(3) limit with m{pi}=mK{approx}140 MeV for which no resonances exist.
Examining CP Symmetry in Strange Baryon Decays
Luk, K B
2000-01-01
Non-conservation of CP symmetry can manisfest itself in non-leptonic hyperon decays as a difference in the decay parameter between the strange-baryon decay and its charge conjugate. By comparing the decay distribution in the $\\Lambda$ helicity frame for the decay sequence $\\Xi^{-} \\to \\Lambda \\pi^{-}$, $\\Lambda \\to p \\pi^{-}$ with that of $\\bar{\\Xi}^{+}$ decay, E756 at Fermilab did not observe any CP-odd effect at the $10^{-2}$ level. The status of a follow-up experiment, HyperCP (FNAL E871), to search for CP violation in charged $\\Xi-\\Lambda$ decay with a sensitivity of $10^{-4}$ is also presented.
Leptogenesis and gravity: Baryon asymmetry without decays
McDonald, J. I.; Shore, G. M.
2017-03-01
A popular class of theories attributes the matter-antimatter asymmetry of the Universe to CP-violating decays of super-heavy BSM particles in the Early Universe. Recently, we discovered a new source of leptogenesis in these models, namely that the same Yukawa phases which provide the CP violation for decays, combined with curved-spacetime loop effects, lead to an entirely new gravitational mechanism for generating an asymmetry, driven by the expansion of the Universe and independent of the departure of the heavy particles from equilibrium. In this Letter, we build on previous work by analysing the full Boltzmann equation, exploring the full parameter space of the theory and studying the time-evolution of the asymmetry. Remarkably, we find regions of parameter space where decays play no part at all, and where the baryon asymmetry of the Universe is determined solely by gravitational effects.
Spin-orbit interactions between two baryons
Energy Technology Data Exchange (ETDEWEB)
Takeuchi, Sachiko [Japan College of Social Work, Kiyose, Tokyo (Japan); Morimatsu, Osamu [High Energy Accelerator Research Organization, Tanashi Branch (KEK-Tanashi), Tanashi, Tokyo (Japan); Tani, Yoshihiro; Oka, Makoto [Tokyo Inst. of Tech. (Japan). Dept. of Physics
2000-04-01
The spin-orbit interactions in the quark cluster models are reviewed in this article. The observed spin-orbit force between two nucleons is strong, while that in the excited baryons or in the {lambda}N interaction is small. We try to sort out whether the quark cluster model can produce a spin-orbit force which explains these features simultaneously. Various works which include the spin-orbit force with different origins such as gluons, mesons, or coupling to other channels are compared to each other. The roles of the symmetric and anti-symmetric spin- orbit forces in the NN scattering phase shifts and in the YN low-energy cross sections and the phase shifts are investigated. (author)
On light baryons and their excitations
Eichmann, Gernot; Sanchis-Alepuz, Helios
2016-01-01
We study ground states and excitations of light octet and decuplet baryons within the framework of Dyson-Schwinger and Faddeev equations. We improve upon similar approaches by explicitly taking into account the momentum-dependent dynamics of the quark-gluon interaction that leads to dynamical chiral symmetry breaking. We perform calculations in both the three-body Faddeev framework and the quark-diquark approximation in order to assess the impact of the latter on the spectrum. Our results indicate that both approaches agree well with each other. The resulting spectra furthermore agree one-to-one with experiment, provided well-known deficiencies of the rainbow-ladder approximation are compensated for. We also discuss the mass evolution of the Roper and the excited Delta with varying pion mass and analyse the internal structure in terms of their partial wave decompositions.
How do galaxies get their baryons?
Conselice, Christopher J
2011-01-01
Understanding how galaxies obtain baryons, their stars and gas, over cosmic time is traditionally approached in two different ways - theoretically and observationally. In general, observational approaches to galaxy formation include measuring basic galaxy properties, such as luminosities, stellar masses, rotation speeds, star formation rates and how these features evolve through time. Theoretically, cosmologically based models collate the physical effects driving galaxy assembly - mergers of galaxies, accretion of gas, star formation, and feedback, amongst others, to form predictions which are matched to galaxy observables. An alternative approach is to examine directly, in an observational way, the processes driving galaxy assembly, including the effects of feedback. This is a new `third way' towards understanding how galaxies are forming from gas accretion and mergers, and directly probes these effects instead of relying on simulations designed to reproduce observations. This empirical approach towards unde...
Observation of excited $\\Lambda^0_b$ baryons
Aaij, R; Adametz, A; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Beddow, J; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Corti, G; Couturier, B; Cowan, G A; Craik, D; Currie, R; D'Ambrosio, C; David, P; David, P N Y; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Del Buono, L; Deplano, C; Derkach, D; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Domingo Bonal, F; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Elsby, D; Esperante Pereira, D; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauld, R; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Harrison, P F; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hoballah, M; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li, Y; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; von Loeben, J; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Luisier, J; Mac Raighne, A; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Massafferri, A; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McCarthy, J; McGregor, G; McNulty, R; Meissner, M; Merk, M; Merkel, J; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neufeld, N; Nguyen, A D; Nguyen-Mau, C; Nicol, M; Niess, V; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, B K; Palacios, J; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pie Valls, B; Pietrzyk, B; Pilař, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Rosello, M; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schleich, S; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, N A; Smith, E; Smith, M; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ubeda Garcia, M; Ukleja, A; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Vesterinen, M; Viaud, B; Videau, I; Vieira, D; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zvyagin, A
2012-01-01
Using $pp$ collision data corresponding to 1.0~fb^{-1} integrated luminosity collected by the LHCb detector, two narrow states are observed in the $\\Lambda_b^0\\pi^+\\pi^-$ spectrum with masses $5911.95\\pm 0.12(\\mbox{stat})\\pm 0.03(\\mbox{syst})\\pm 0.66(\\Lambda_b^0\\mbox{ mass})$ MeV/$c^2$ and $5919.76\\pm 0.07(\\mbox{stat})\\pm 0.02(\\mbox{syst})\\pm 0.66(\\Lambda_b^0\\mbox{ mass})$ MeV/$c^2$. The significances of the observations are 4.9 and 10.1 standard deviations, respectively. These states are interpreted as the orbitally-excited $\\Lambda_b^0$ baryons, $\\Lambda_b^{*0}(5912)$ and $\\Lambda_b^{*0}(5920)$.
Baryon transition form factors at the pole
Energy Technology Data Exchange (ETDEWEB)
Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.
2016-12-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the $G_M$, $G_E$, and $G_C$ form factors for the $\\Delta(1232)$ resonance excitation at the Breit-Wigner resonance and pole positions up to $Q^2=5$ GeV$^2$. We also explore the $E/M$ and $S/M$ ratios as functions of $Q^2$. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Observation of a new charmed baryon
Albrecht, H.; Ehrlichmann, H.; Hamacher, T.; Hofmann, R. P.; Kirchhoff, T.; Nau, A.; Nowak, S.; Schröder, H.; Schulz, H. D.; Walter, M.; Wurth, R.; Hast, C.; Kapitza, H.; Kolanoski, H.; Kosche, A.; Lange, A.; Lindner, A.; Mankel, R.; Schieber, M.; Siegmund, T.; Spaan, B.; Thurn, H.; Töpfer, D.; Wegener, D.; Bittner, M.; Eckstein, P.; Paulini, M.; Reim, K.; Wegener, H.; Eckmann, R.; Mundt, R.; Oest, T.; Reiner, R.; Schmidt-Parzefall, W.; Stiewe, J.; Werner, S.; Ehret, K.; Hofmann, W.; Hüpper, A.; Khan, S.; Knöpfle, K. T.; Seeger, M.; Spengler, J.; Britton, D. I.; Charlesworth, C. E. K.; Edwards, K. W.; Hyatt, E. R. F.; Krieger, P.; Macfarlane, D. B.; Patel, P. M.; Prentice, J. D.; Saull, P. R. B.; Tzamariudaki, K.; van de Water, R. G.; Yoon, T.-S.; Reβing, D.; Schmidtler, M.; Schneider, M.; Schubert, K. R.; Strahl, K.; Waldi, R.; Weseler, S.; Kernel, G.; Križan, P.; Križnič, E.; Podobnik, T.; Živko, T.; Balagura, V.; Belyaev, I.; Chechelnitsky, S.; Danilov, M.; Droutskoy, A.; Gershtein, Yu.; Golutvin, A.; Korolko, I.; Kostina, G.; Litvintsev, D.; Lubimov, V.; Pakhlov, P.; Semenov, S.; Snizhko, A.; Tichomirov, I.; Zaitsev, Yu.; Argus Collaboration
1993-11-01
Using the ARGUS detector at the e+e- storage ring DORIS II at DESY, we have observed a new charmed baryon state in the channel Λc+π+π-. (All references to a specific charged state also imply the charge conjugate state.) The mass of this state was measured to be (2626.6 ± 0.5 ± 1.5) MeV/ c2. The product of the production cross section and branching ratio for this channel was determined to be (11.5 ± 2.5 ± 3.0) pb, and the natural width estimated to be smaller than 3.2 MeV/ c2 at 90% CL.
Quantum Operator Design for Lattice Baryon Spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Lichtl, Adam [Carnegie Mellon Univ., Pittsburgh, PA (United States)
2006-09-07
A previously-proposed method of constructing spatially-extended gauge-invariant three-quark operators for use in Monte Carlo lattice QCD calculations is tested, and a methodology for using these operators to extract the energies of a large number of baryon states is developed. This work is part of a long-term project undertaken by the Lattice Hadron Physics Collaboration to carry out a first-principles calculation of the low-lying spectrum of QCD. The operators are assemblages of smeared and gauge-covariantly-displaced quark fields having a definite flavor structure. The importance of using smeared fields is dramatically demonstrated. It is found that quark field smearing greatly reduces the couplings to the unwanted high-lying short-wavelength modes, while gauge field smearing drastically reduces the statistical noise in the extended operators.
First observation of doubly charmed baryons
Energy Technology Data Exchange (ETDEWEB)
M. A. Moinester et al.
2003-09-25
The SELEX experiment (E781) at Fermilab has observed two statistically compelling high mass states near 3.6 GeV/c{sup 2}, decaying to {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +} and {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +}{pi}{sup +}. These final states are Cabibbo-allowed decay modes of doubly charmed baryons {Xi}{sub cc}{sup +} and {Xi}{sub cc}{sup ++}, respectively. The masses are in the range expected from theoretical considerations, but the spectroscopy is surprising. SELEX also has weaker preliminary evidence for a state near 3.8 GeV/c{sup 2}, a high mass state decaying to {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +}{pi}{sup +}, possibly an excited {Xi}{sub cc}{sup ++} (ccu*). Data are presented and discussed.
Relativistic five-quark equations and hybrid baryon spectroscopy
Gerasyuta, S M
2002-01-01
The relativistic five-quark equations are found in the framework of the dispersion relation technique. The Behavior of the low-energy five-particle amplitude is determined by its leading singularities in the pair invariant masses. The solutions of these equations using the method based on the extraction leading singularities of the amplitudes are obtained. The mass spectra of nucleon and delta-isobar hybrid baryons are calculated. The calculations of hybrid baryon amplitudes estimate the contributions of four subamplitudes. The main contributions to the hybrid baryon amplitude are determined by the subamplitudes, which include the excited gluon states.
Diquark correlations in baryons: the Interacting Quark Diquark Model
Santopinto, E
2015-01-01
A review of the underlying ideas of the Interacting Quark Diquark Model (IQDM) that asses the baryon spectroscopy in terms of quark diquark degrees of freedom is given, together with a discussion of the missing resonances problem. Some ideas about its generalization the heavy baryon spectroscopy is given.s of freedom is given, together with a discussion of the missing resonances problem. Some ideas about its generalization the heavy baryon spectroscopy is given.The results are compared to the existing experimental data.
Dynamically generated open charmed baryons beyond the zero range approximation
Jimenez-Tejero, C E; Vidaña, I
2009-01-01
The interaction of the low lying pseudo-scalar mesons with the ground state baryons in the charm sector is studied within a coupled channel approach using a t-channel vector-exchange driving force. The amplitudes describing the scattering of the pseudo-scalar mesons off the ground-state baryons are obtained by solving the Lippmann--Schwinger equation. We analyze in detail the effects of going beyond the $t=0$ approximation. Our model predicts the dynamical generation of several open charmed baryon resonances in different isospin and strangeness channels, some of which can be clearly identified with recently observed states.
Dark Matter and the Baryon Asymmetry of the Universe
Farrar, G R; Farrar, Glennys R.; Zaharijas, Gabrijela
2004-01-01
We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\gsi 10%$, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$.
Medium modifications of baryon properties in nuclear matter and hypernuclei
Liang, J S
2013-01-01
We study the medium modifications of baryon properties in nuclear many-body systems, especially in $\\Lambda$ hypernuclei. The nucleon and the $\\Lambda$ hyperon are described in the Friedberg-Lee model as nontopological solitons which interact through the self-consistent exchange of scalar and vector mesons. The quark degrees of freedom are explicitly considered in the model, so that the medium effects on baryons could be investigated. It is found that the model can provide reasonable descriptions for nuclear matter, finite nuclei, and $\\Lambda$ hypernuclei. The present model predicts a significant increase of the baryon radius in nuclear medium.
Missing Baryons and the Warm-Hot Intergalactic Medium
Nicastro, F; Elvis, Martin
2007-01-01
Stars and gas in galaxies, hot intracluster medium, and intergalactic photo-ionized gas make up at most half of the baryons that are expected to be present in the universe. The majority of baryons are still missing and are expected to be hidden in a web of warm-hot intergalactic medium. This matter was shock-heated during the collapse of density perturbations that led to the formation of the relaxed structures that we see today. Finding the missing baryons and thereby producing a complete inventory of possibly the only detectable component of the energy-mass budget of the universe is crucial to validate or invalidate our standard cosmological model.
Are narrow mesons, baryons and dibaryons evidence for multiquark states?
Energy Technology Data Exchange (ETDEWEB)
Tatischeff, B.; Yonnet, J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire
2000-07-01
Several narrow structures have been progressively observed since the last fifteen years, in di-baryonic invariant mass spectra or in missing mass spectra. More recently, narrow structures were observed in baryonic and now in mesonic mass spectra. Since these small peaks appear at fixed masses, independently of the experiment, they are associated with real states. There is no room to explain these states within classical nuclear physics taking into account baryonic and mesonic degrees of freedom. An interpretation is proposed, which associate these narrow structures with two coloured quark clusters. (authors)
Stability issues with baryons in AdS/CFT
Sfetsos, Konstadinos
2008-01-01
We consider baryon vertices within the gauge/gravity correspondence for a class of curved backgrounds. The holographic description based on the N=4 SYM theory for SU(N) allows classical solutions representing bound states of k-quarks with k less than or equal to N. We construct the corresponding classical configurations and perform a stability analysis. We present the details for the theory at the conformal point and at finite temperature and show that there is a critical value of k, below which there is instability. This may also arise when the baryon reaches a critical size. We also extend our treatment to magnetically charged baryon vertices.
Baryons and Low-Density Baryonic Matter in 1+1 Dimensional Large N_c QCD with Heavy Quarks
Adhikari, Prabal; Jamgochian, Arec; Kumar, Nilay
2012-01-01
This paper studies baryons and baryonic matter in the combined large N_c and heavy quark mass limits of QCD in 1+1 dimension. In this non-relativistic limit, baryons are composed of N_c quarks that interact, at leading order in N_c, through a color Coulomb potential. Using variational techniques, very accurate calculations of single baryon masses and interaction energies of low-density baryon crystal are performed. These results are used to cross-check a general numerical approach applicable for arbitrary quark masses and baryon densities recently proposed by Bringoltz, which is based on a lattice in a finite box with periodic boundary conditions. The Bringoltz method differs from a previous approach of Salcedo, et al. in its treatment of a finite box effect - namely gauge configurations that wind around the box. One might expect these effects to be small for large enough boxes, in which the baryon density approaches zero to high accuracy at the edges. However, the effects of these windings appear to be quite...
Reddy, Naveen; Steidel, Charles
2016-08-01
We propose Spitzer IRAC 3.6 micron observations to cover the three remaining fields of a large spectroscopic survey of galaxies, AGN, and QSOs in the same cosmic volumes at z~2-3. The IRAC data will be used to probe the stellar populations in these galaxies and to understand how galaxy properties (e.g., stellar masses, ages, reddening, star-formation rates) depend on the flow of baryons into and out of galaxies, as well as identify those properties of galaxies that are conducive to the escape of ionizing radiation at high redshift. The dense spectroscopic sampling of the targeted fields have provided unique insights into metal enrichment as a function of galactocentric radius and the statistical correlation between galaxies and metals in the inter-galactic medium. Our goal is to quantify how the distribution of metals in the circum-galactic and inter-galactic media (CGM/IGM) depend on the stellar masses, ages, and star formation rates of galaxies. Moreover, in an effort to clarify the role of galaxies in reionizing the Universe (and keeping it ionized), we wish to understand the types of stellar populations (e.g., stellar masses, ages) that influence the propensity of galaxies to leak ionizing radiation. Our preliminary observations suggest that bluer galaxies with lower star-formation rates have larger escape fractions, but the results are tentative without the inclusion of the IRAC data proposed here. A modest investment of just 13.1 hours (including overhead), divided among the three fields will cover a total of approximately 200 spectroscopically-confirmed z~2-3 galaxies that span two orders of magnitude in bolometric luminosity and stellar mass. The proposed IRAC imaging will allow us to fully leverage the existing spectroscopic samples that form the backbone of our survey of the baryon cycle and escaping ionizing radiation at high redshift.
Neutrino mass, dark matter, and Baryon asymmetry via TeV-scale physics without fine-tuning.
Aoki, Mayumi; Kanemura, Shinya; Seto, Osamu
2009-02-01
We propose an extended version of the standard model, in which neutrino oscillation, dark matter, and the baryon asymmetry of the Universe can be simultaneously explained by the TeV-scale physics without assuming a large hierarchy among the mass scales. Tiny neutrino masses are generated at the three-loop level due to the exact Z2 symmetry, by which the stability of the dark matter candidate is guaranteed. The extra Higgs doublet is required not only for the tiny neutrino masses but also for successful electroweak baryogenesis. The model provides discriminative predictions especially in Higgs phenomenology, so that it is testable at current and future collider experiments.
Mass spectra and Regge trajectories of , , and baryons
Shah, Zalak; Thakkar, Kaushal; Rai, Ajay Kumar; Vinodkumar, P. C.
2016-12-01
We calculate the mass spectra of the singly charmed baryons (, , and ) using the hypercentral constituent quark model (hCQM). The hyper color Coulomb plus linear potential is used to calculate the masses of positive (up to ) and negative (up to ) parity excited states. The spin-spin, spin-orbital and tensor interaction terms are also incorporated for mass spectra. We have compared our results with other theoretical and lattice QCD predictions for each baryon. Moreover, the known experimental results are also reasonably close to our predicted masses. By using the radial and orbital excitation, we construct Regge trajectories for the baryons in the (n, M2) plane and find their slopes and intercepts. Other properties of these baryons, like magnetic moments, radiative transitions and radiative decay widths, are also calculated successfully. Supported in part (A. K. Rai) by DST, India (SERB Fast Track Scheme SR/FTP/PS-152/2012)
Dirac's Covariant Constraint Dynamics Applied to the Baryon Spectrum
Whitney, Joshua; Crater, Horace
2010-02-01
A baryon is a hadron containing three quarks in a combination of up, down, strange, charm, or bottom. For prediction of the baryon energy spectrum, a baryon is modeled as a three-body system with the interacting forces coming from a set of two-body potentials that depend on the distance between the quarks, the spin-spin and spin-orbit angular momentum coupling terms, and a tensor term. Techniques and equations are derived from Todorov's work on constraint dynamics and the quasi-potential equation together with Two Body Dirac equations developed by Crater and Van Alstine, and adapted to this specific problem by further use of Sazdjian's N-body constraints dynamics for general confined systems. Baryon spectroscopy results are presented and compared with experiment. Typically, a best fit method is used in the analyses that employ several different algorithms, including a gradient approach, Monte Carlo modeling, and simulated annealing methods. )
Baryon production in $e^{+}e^{-}$-annihilation at PETRA
Bartel, Wulfrin; Dittmann, P; Eichler, R; Felst, R; Haidt, Dieter; Krehbiel, H; Meier, K; Naroska, Beate; O'Neill, L H; Steffen, P; Wenninger, Horst; Zhang, Y; Elsen, E E; Helm, M; Petersen, A; Warming, P; Weber, G; Bethke, Siegfried; Drumm, H; Heintze, J; Heinzelmann, G; Hellenbrand, K H; Heuer, R D; Von Krogh, J; Lennert, P; Kawabata, S; Matsumura, H; Nozaki, T; Olsson, J; Rieseberg, H; Wagner, A; Bell, A; Foster, F; Hughes, G; Wriedt, H; Allison, J; Ball, A H; Bamford, G; Barlow, R; Bowdery, C K; Duerdoth, I P; Hassard, J F; King, B T; Loebinger, F K; MacBeth, A A; McCann, H; Mills, H E; Murphy, P G; Prosper, H B; Stephens, K; Clarke, D; Goddard, M C; Marshall, R; Pearce, G F; Kobayashi, T; Komamiya, S; Koshiba, M; Minowa, M; Nozaki, M; Orito, S; Sato, A; Suda, T; Takeda, H; Totsuka, Y; Watanabe, Y; Yamada, S; Yanagisawa, C
1981-01-01
Data on p and Lambda production by e/sup +/e/sup -/-annihilation at CM energies between 30 and 36 GeV are presented. Indication for an angular anticorrelation in events with baryon-antibaryon pairs is seen.
Two-Baryon Correlation Functions in 2-flavour QCD
Francis, Anthony; Rae, Thomas D; Wittig, Hartmut
2013-01-01
We present first results for two-baryon correlation functions, computed using $N_f=2$ flavours of O($a$) improved Wilson quarks, with the aim of explaining potential dibaryon bound states, specifically the H-dibaryon. In particular, we use a GEVP to isolate the groundstate using two-baryon (hyperon-hyperon) correlation functions $\\big(\\langle C_{XY}(t)C_{XY}(0) \\rangle$, where $XY=\\Lambda\\Lambda, \\Sigma\\Sigma, N\\Xi, \\cdots\\big)$, each of which has an overlap with the H-dibaryon. We employ a `blocking' algorithm to handle the large number of contractions, which may easily be extended to N-baryon correlation functions. We also comment on its application to the analysis of single baryon masses ($n$, $\\Lambda$, $\\Xi$, $\\cdots$). This study is performed on an isotropic lattice with $m_\\pi = 460$ MeV, $m_\\pi L = 4.7$ and $a = 0.063$ fm.
Meson-Baryon Interactions in Unitarized Chiral Perturbation Theory
García-Recio, C; Ruiz-Arriola, E; Vacas, M J V
2003-01-01
Meson-Baryon Interactions can be successfully described using both Chiral Symmetry and Unitarity. The $s-$wave meson-baryon scattering amplitude is analyzed in a Bethe-Salpeter coupled channel formalism incorporating Chiral Symmetry in the potential. Two body coupled channel unitarity is exactly preserved. The needed two particle irreducible matrix amplitude is taken from lowest order Chiral Perturbation Theory in a relativistic formalism. Off-shell behavior is parameterized in terms of low energy constants. The relation to the heavy baryon limit is discussed. The position of the complex poles in the second Riemann sheet of the scattering amplitude determine masses and widths baryonic resonances of the N(1535), N(1670), $\\Lambda (1405)$ and $\\Lambda(1670)$ resonances which compare well with accepted numbers.
Chiral Dynamics of Baryons in a Lorentz Covariant Quark Model
Faessler, A; Lyubovitskij, V E; Pumsa-ard, K; Faessler, Amand; Gutsche, Th.
2006-01-01
We develop a manifestly Lorentz covariant chiral quark model for the study of baryons as bound states of constituent quarks dressed by a cloud of pseudoscalar mesons. The approach is based on a non-linear chirally symmetric Lagrangian, which involves effective degrees of freedom - constituent quarks and the chiral (pseudoscalar meson) fields. In a first step, this Lagrangian can be used to perform a dressing of the constituent quarks by a cloud of light pseudoscalar mesons and other heavy states using the calculational technique of infrared dimensional regularization of loop diagrams. We calculate the dressed transition operators with a proper chiral expansion which are relevant for the interaction of quarks with external fields in the presence of a virtual meson cloud. In a second step, these dressed operators are used to calculate baryon matrix elements. Applications are worked out for the masses of the baryon octet, the meson-nucleon sigma terms, the magnetic moments of the baryon octet, the nucleon charge...
Electromagnetic form factors of baryons in an algebraic approach
Energy Technology Data Exchange (ETDEWEB)
Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 Mexico D.F. (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
1999-07-01
We present a simultaneous analysis of elastic and transition form factors of the nucleon. The calculations are performed in the framework of an algebraic model of baryons. Effects of meson cloud couplings are considered. (Author)
Electromagnetic form factors of baryons in an algebraic approach
Bijker, R
1999-01-01
We present a simultaneous analysis of elastic and transition form factors of the nucleon. The calculations are performed in the framework of an algebraic model of baryons. Effects of meson cloud couplings are considered.
Octet baryon electromagnetic form factors in nuclear medium
Ramalho, G; Thomas, A W
2012-01-01
We study the octet baryon electromagnetic form factors in nuclear matter using the covariant spectator quark model extended to the nuclear matter regime. The parameters of the model in vacuum are fixed by the study of the octet baryon electromagnetic form factors. In nuclear matter the changes in hadron properties are calculated by including the relevant hadron masses and the modification of the pion-baryon coupling constants calculated in the quark-meson coupling model. In nuclear matter the magnetic form factors of the octet baryons are enhanced in the low $Q^2$ region, while the electric form factors show a more rapid variation with $Q^2$. The results are compared with the modification of the bound proton electromagnetic form factors observed at Jefferson Lab. In addition, the corresponding changes for the bound neutron are predicted.
Chiral extrapolations and strangeness in the baryon ground states
Lutz, Matthias F M
2013-01-01
We review the quark-mass dependence of the baryon octet and decuplet masses as obtained from recent lattice simulations of the BMW, PACS-CS, LHPC, HSC and QCDSF-UKQCD groups. Our discussion relies on the relativistic chiral Lagrangian and large-$N_c$ sum rule estimates of the counter terms relevant for the baryon masses at N$^3$LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. In our analysis the physical masses are reproduced exactly by means of a suitable set of linear constraints. A quantitative and simultaneous description of all lattice results is achieved in terms of a six parameter fit, where the symmetry conserving counter term that are relevant at N$^3$LO are not yet being used. For pion masses larger than 300 MeV there appears to be an approximate linear pion-mass dependence of all octet and decuplet baryon masses. We discuss the pion- and strangeness sigma terms of the baryon octet states.
Study of ψ(3770 decaying to baryon anti-baryon pairs
Directory of Open Access Journals (Sweden)
Li-Gang Xia
2016-05-01
Full Text Available To study the decays of ψ(3770 going to baryon anti-baryon pairs (BB¯, all available experiments of measuring the cross sections of e+e−→BB¯ at center-of-mass energy ranging from 3.0 GeV to 3.9 GeV are combined. To relate the baryon octets, a model based on the SU(3 flavor symmetry is used and the SU(3 breaking effects are also considered. Assuming the electric and magnetic form factors are equal (|GE|=|GM|, a global fit including the interference between the QED process and the resonant process is performed. The branching fraction of ψ(3770→BB¯ is determined to be (2.4±0.8±0.3×10−5, (1.7±0.6±0.1×10−5, (4.5±0.9±0.1×10−5, (4.5±0.9±0.1×10−5, (2.0±0.7±0.1×10−5, and (2.0±0.7±0.1×10−5 for B=p,Λ,Σ+,Σ0,Ξ− and Ξ0, respectively, where the first uncertainty is from the global fit and the second uncertainty is the systematic uncertainty due to the assumption |GE|=|GM|. They are at least one order of magnitude larger than a simple scaling of the branching fraction of J/ψ/ψ(3686→BB¯.
Possible hidden-charm molecular baryons composed of an anti-charmed meson and a charmed baryon
Institute of Scientific and Technical Information of China (English)
YANG Zhong-Cheng; SUN Zhi-Feng; HE Jun; LIU Xiang; ZHU Shi-Lin
2012-01-01
Using the one-boson-exchange model,we studied the possible existence of very loosely bound hidden-charm molecular baryons composed of an anti-charmed meson and a charmed baryon.Our numerical results indicate that the ∑c(D)* and ∑c(D) states exist,but that the ∑c(D) and ∑c(D)* molecular states do not.
Heavy baryons as polarimeters at colliders
Galanti, Mario; Grossman, Yuval; Kats, Yevgeny; Stamou, Emmanuel; Zupan, Jure
2015-01-01
In new-physics processes that produce b or c jets, a measurement of the initial b or c-quark polarization could provide crucial information about the structure of new physics. In the heavy-quark limit, the b and c-quark polarizations are preserved in the lightest baryons they hadronize into, Lambda_b and Lambda_c, respectively. We revisit the prediction for the polarization retention after the hadronization process and extend it to the case of transverse polarization. We show how ATLAS and CMS can measure the b-quark polarization using semileptonic Lambda_b decays, and the c-quark polarization using Lambda_c+ -> p K- pi+ decays. For calibrating both measurements we suggest to use ttbar samples in which the polarizations can be measured with a precision of order 10% using 100/fb of data in Run 2 of the LHC. LHCb measurements of the transverse polarization in QCD events are motivated as well. An existing LHCb analysis can be significantly improved for this purpose.
Conformal symmetry and light flavor baryon spectra
Kirchbach, M
2010-01-01
The degeneracy among parity pairs systematically observed in the N and Delta spectra is interpreted as signature for conformal symmetry realization in the light flavor baryon sector in consequence of AdS/CFT. The case is made by showing that all the observed N and Delta resonances with masses below 2500 MeV distribute fairly well over the first levels of a unitary representation of the conformal group, a representation that covers the spectrum of a quark-diquark system, placed directly on the AdS_5 cone, conformally compactified to R^1*S^3. The free geodesic motion on the S^3 manifold is described by means of the scalar conformal equation there, which is of the Klein-Gordon type. The equation is then gauged by the "curved" Coulomb potential that has the form of a cotangent function. Conformal symmetry is not exact, this because the gauge potential slightly modifies the conformal centrifugal barrier of the free geodesic motion. Thanks to this, the degeneracy between P11-S11 pairs from same level is relaxed, wh...
BASE - The Baryon Antibaryon Symmetry Experiment
Smorra, C.; Blaum, K.; Bojtar, L.; Borchert, M.; Franke, K. A.; Higuchi, T.; Leefer, N.; Nagahama, H.; Matsuda, Y.; Mooser, A.; Niemann, M.; Ospelkaus, C.; Quint, W.; Schneider, G.; Sellner, S.; Tanaka, T.; Van Gorp, S.; Walz, J.; Yamazaki, Y.; Ulmer, S.
2015-11-01
The Baryon Antibaryon Symmetry Experiment (BASE) aims at performing a stringent test of the combined charge parity and time reversal (CPT) symmetry by comparing the magnetic moments of the proton and the antiproton with high precision. Using single particles in a Penning trap, the proton/antiproton g-factors, i.e. the magnetic moment in units of the nuclear magneton, are determined by measuring the respective ratio of the spin-precession frequency to the cyclotron frequency. The spin precession frequency is measured by non-destructive detection of spin quantum transitions using the continuous Stern-Gerlach effect, and the cyclotron frequency is determined from the particle*s motional eigenfrequencies in the Penning trap using the invariance theorem. By application of the double Penning-trap method we expect that in our measurements a fractional precision of δg/g 10-9 can be achieved. The successful application of this method to the antiproton will consist a factor 1000 improvement in the fractional precision of its magnetic moment. The BASE collaboration has constructed and commissioned a new experiment at the Antiproton Decelerator (AD) of CERN. This article describes and summarizes the physical and technical aspects of this new experiment.
First observation of a baryonic Bc+ decay.
Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Brown, H; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chefdeville, M; Chen, S; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cojocariu, L; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Counts, I; Couturier, B; Cowan, G A; Craik, D C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dreimanis, K; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Ely, S; Esen, S; Evans, H-M; Evans, T; Falabella, A; Färber, C; Farinelli, C; Farley, N; Farry, S; Fay, Rf; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; García Pardiñas, J; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gavardi, L; Gavrilov, G; Geraci, A; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Giani', S; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Henry, L; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Hunt, P; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kelsey, M; Kenyon, I R; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Klimaszewski, K; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lowdon, P; Lu, H; Lucchesi, D; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Malinin, A; Manca, G; Mancinelli, G; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A
2014-10-10
A baryonic decay of the B(c)(+) meson, B(c)(+) → J/ψppπ(+), is observed for the first time, with a significance of 7.3 standard deviations, in pp collision data collected with the LHCb detector and corresponding to an integrated luminosity of 3.0 fb(-1) taken at center-of-mass energies of 7 and 8 TeV. With the B(c)(+) → J/ψπ(+) decay as the normalization channel, the ratio of branching fractions is measured to be B(B(c)(+) → J/ψppπ(+))/B(B(c)(+) → J/ψπ(+)) = 0.143(-0.034)(+0.039)(stat) ± 0.013(syst). The mass of the B(c)(+) meson is determined as M(B(c)(+) = 6274.0 ± 1.8(stat) ± 0.4(syst) MeV/c(2), using the B(c)(+) → J/ψppπ(+) channel.
The Photon-Baryon Governed Universe
Directory of Open Access Journals (Sweden)
Laszlo A. Marosi
2012-01-01
Full Text Available In a previous paper we postulated that the repulsive force responsible for the universal expansion is associated with the excitation of the empty space (quantum vacuum and the excitation energy is represented by the energy of the cosmic microwave background (CMB. In this paper, we show that the concept of the repulsive space expanding photon field (i can successfully be applied to explain the local velocity anomaly of the Milky Way Galaxy as shown by Faber and Burstein (1998 and Tully (1998, (ii offers a convincing explanation of the still disputed question of the cosmological expansion on local and intergalactic scales discussed by Cooperstock et al. (1998, and (iii explains the redshift (RS of the CMB in accordance with the law of energy conservation without the need for dark matter (DM and dark energy (DE. Probably the most remarkable result of this model (abbreviated as photon/baryon: PB model in the following discussion is that the individual voids building up the soup-bubble- (SB- like galaxy distribution are the governing dynamical components of the universal expansion. Further consequence implies that the universe is considerably older than the interpretation of the Hubble constant as expansion velocity suggests.
Structure and reactions of pentaquark baryons
Indian Academy of Sciences (India)
Atsushi Hosaka
2006-04-01
We review the current status of the exotic pentaquark baryons. After a brief look at experiments of both positive and negative results, we discuss theoretical methods to study the structure and reactions for the pentaquarks. First we introduce the quark model and the chiral soliton model, where we discuss the relation of mass spectrum and parity with some emphasis on the role of chiral symmetry. It is always useful to picture the structure of the pentaquarks in terms of quarks. As for other methods, we discuss a model-independent method, and briefly mention the results from the lattice and QCD sum rule. Decay properties are then studied in some detail, which is one of the important properties of +. We investigate the relation between the decay width and the quark structure having certain spin-parity quantum numbers. Through these analyses, we consider as plausible quantum numbers of +, = 3/2-. In the last part of this note, we discuss production reactions of + which provide links between the theoretical models and experimental information. We discuss photoproductions and hadron-induced reactions which are useful to explore the nature of +.
BASE - The Baryon Antibaryon Symmetry Experiment
Smorra, C; Bojtar, L.; Borchert, M.; Franke, K.A.; Higuchi, T.; Leefer, N.; Nagahama, H.; Matsuda, Y.; Mooser, A.; Niemann, M.; Ospelkaus, C.; Quint, W.; Schneider, G.; Sellner, S.; Tanaka, T.; Van Gorp, S.; Walz, J.; Yamazaki, Y.; Ulmer, S.
2015-01-01
The Baryon Antibaryon Symmetry Experiment (BASE) aims at performing a stringent test of the combined charge parity and time reversal (CPT) symmetry by comparing the magnetic moments of the proton and the antiproton with high precision. Using single particles in a Penning trap, the proton/antiproton $g$-factors, i.e. the magnetic moment in units of the nuclear magneton, are determined by measuring the respective ratio of the spin-precession frequency to the cyclotron frequency. The spin precession frequency is measured by non-destructive detection of spin quantum transitions using the continuous Stern-Gerlach effect, and the cyclotron frequency is determined from the particle's motional eigenfrequencies in the Penning trap using the invariance theorem. By application of the double Penning-trap method we expect that in our measurements a fractional precision of $\\delta g/g$ 10$^{-9}$ can be achieved. The successful application of this method to the antiproton will represent a factor 1000 improvement in the frac...
Power oscillation damping controller
DEFF Research Database (Denmark)
2012-01-01
A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...
Energy Technology Data Exchange (ETDEWEB)
Somogyi, Gabor [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Zurich Univ. (Switzerland). Inst. for Theoretical Physics; Smith, Robert E. [Zurich Univ. (Switzerland). Inst. for Theoretical Physics
2009-10-15
Baryonic Acoustic Oscillation (BAO) features are amplified for baryon and slightly damped for CDM spectra. If we compare the total matter power spectra in the 2- and 1-component fluid approaches, then we find excellent agreement, with deviations being < 0.5% throughout the evolution. Consequences: high precision modeling of the large-scale distribution of baryons in the Universe can not be achieved through an effective mean-mass 1-component fluid approximation; detection significance of BAO will be amplified in probes that study baryonic matter, relative to probes that study the CDM or total mass only. The CDM distribution can be modeled accurately at late times and the total matter at all times. This is good news for probes that are sensitive to the total mass, such as gravitational weak lensing as existing modeling techniques are good enough. Lastly, we identify an analytic approximation that greatly simplifies the evaluation of the full PT expressions, and it is better than < 1% over the full range of scales and times considered. (orig.)
Instructive discussion of effective block algorithm for baryon-baryon correlators
Nemura, Hidekatsu
2015-01-01
We describe a fairly specific idea to calculate efficiently a large number of four-point correlation functions, which are primary quantities to study the nuclear force and hyperonic nuclear forces from lattice QCD, for various baryon-baryon (BB) channels. We discuss how the effective block algorithm significantly reduces the number of iterations with considering the four-point correlator of proton-$\\Lambda$ system as a specific example. The effective block algorithm is applied to calculate the 52 channels of four-point correlation functions from nucleon-nucleon to $\\Xi-\\Xi$, in order to study the complete set of isospin symmetric BB interactions. The elapsed times measured on hybrid parallel computation on BlueGene/Q show reasonable performances at various combinations of the number of OpenMP threads and the number of MPI nodes. The numerical results are benchmarked with the results from the unified contraction algorithm for all of computed sites of 52 four-point correlators.
Instructive discussion of an effective block algorithm for baryon-baryon correlators
Nemura, Hidekatsu
2016-10-01
We describe an approach for the efficient calculation of a large number of four-point correlation functions for various baryon-baryon (BB) channels, which are the primary quantities for studying the nuclear and hyperonic nuclear forces from lattice quantum chromodynamics. Using the four-point correlation function of a proton- Λ system as a specific example, we discuss how an effective block algorithm significantly reduces the number of iterations. The effective block algorithm is applied to calculate 52 channels of the four-point correlation functions from nucleon-nucleon to Ξ- Ξ, in order to study the complete set of isospin symmetric BB interactions. The elapsed times measured for hybrid parallel computation on BlueGene/Q demonstrate that the performance of the present algorithm is reasonable for various combinations of the number of OpenMP threads and the number of MPI nodes. The numerical results are compared with the results obtained using the unified contraction algorithm for all computed sites of the 52 four-point correlators.
DEFF Research Database (Denmark)
Lindberg, Erik
1997-01-01
In order to obtain insight in the nature of nonlinear oscillators the eigenvalues of the linearized Jacobian of the differential equations describing the oscillator are found and displayed as functions of time. A number of oscillators are studied including Dewey's oscillator (piecewise linear...... with negative resistance), Kennedy's Colpitts-oscillator (with and without chaos) and a new 4'th order oscillator with hyper-chaos....
Structure of charmed baryons studied by pionic decays
Nagahiro, Hideko; Hosaka, Atsushi; Oka, Makoto; Noumi, Hiroyuki
2016-01-01
We investigate the decays of the charmed baryons aiming at the systematic understanding of hadron internal structures based on the quark model by paying attention to heavy quark symmetry. We evaluate the decay widths from the one pion emission for the known excited states, \\Lambda_c^*(2595), \\Lambda_c^*(2625), \\Lambda_c^*(2765), \\Lambda_c^*(2880) and \\Lambda_c^*(2940), as well as for the ground states \\Sigma_c(2455) and \\Sigma_c^*(2520). The decay properties of the lower excited charmed baryons are well explained, and several important predictions for higher excited baryons are given. We find that the axial-vector type coupling of the pion to the light quarks is essential, which is expected from chiral symmetry, to reproduce the decay widths especially of the low lying \\Lambda_c^* baryons. We emphasize the importance of the branching ratios of \\Gamma(\\Sigma_c^*\\pi)/\\Gamma(\\Sigma_c\\pi) for the study of the nature of higher excited \\Lambda_c^* baryons.
Propagation of heavy baryons in heavy-ion collisions
Das, Santosh K.; Torres-Rincon, Juan M.; Tolos, Laura; Minissale, Vincenzo; Scardina, Francesco; Greco, Vincenzo
2016-12-01
The drag and diffusion coefficients of heavy baryons (Λc and Λb ) in the hadronic phase created in the latter stage of the heavy-ion collisions at RHIC and LHC energies have been evaluated recently. In this work we compute some experimental observables, such as the nuclear suppression factor RA A and the elliptic flow v2 of heavy baryons at RHIC and LHC energies, highlighting the role of the hadronic phase contribution to these observables, which are going to be measured at Run 3 of LHC. For the time evolution of the heavy quarks in the quark and gluon plasma (QGP) and heavy baryons in the hadronic phase, we use the Langevin dynamics. For the hadronization of the heavy quarks to heavy baryons we employ Peterson fragmentation functions. We observe a strong suppression of both the Λc and Λb . We find that the hadronic medium has a sizable impact on the heavy-baryon elliptic flow whereas the impact of hadronic medium rescattering is almost unnoticeable on the nuclear suppression factor. We evaluate the Λc/D ratio at RHIC and LHC. We find that the Λc/D ratio remains unaffected due to the hadronic phase rescattering which enables it as a nobel probe of QGP phase dynamics along with its hadronization.
Spectroscopy of doubly charmed baryons from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Padmanath, M. [Univ. of Graz, Graz (Austria); Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mathur, Nilmani [Tata Inst. of Fundamental Research, Mumbai (India); Peardon, Michael [Trinity College, Dublin (Ireland)
2015-05-06
This study presents the ground and excited state spectra of doubly charmed baryons from lattice QCD with dynamical quark fields. Calculations are performed on anisotropic lattices of size 16³ × 128, with inverse spacing in temporal direction a_{t}⁻¹=5.67(4) GeV and with a pion mass of about 390 MeV. A large set of baryonic operators that respect the symmetries of the lattice yet which retain a memory of their continuum analogues are used. These operators transform as irreducible representations of SU(3)_{F} symmetry for flavor, SU(4) symmetry for Dirac spins of quarks and O(3) for spatial symmetry. The distillation method is utilized to generate baryon correlation functions which are analyzed using the variational fitting method to extract excited states. The lattice spectra obtained have baryonic states with well-defined total spins up to 7/2 and the pattern of low-lying states does not support the diquark picture for doubly charmed baryons. On the contrary the calculated spectra are remarkably similar to the expectations from models with an SU(6)×O(3) symmetry. Various spin-dependent energy splittings between the extracted states are also evaluated.
Another source of baryons in B meson decays
Dunietz, Isard; Falk, A F; Wise, M B; Isard Dunietz; Peter S Cooper; Adam F Falk; Mark B Wise
1994-01-01
It is usually assumed that the production of baryons in B meson decays is induced primarily by the quark level process b\\to c\\bar ud, where the charm quark hadronizes into a charmed baryon. With this assumption, the \\Lambda_c momentum spectrum would indicate that the transition B\\to\\Lambda_c X is dominated by multi-body B decays. However, a closer examination of the momentum spectrum reveals that the mass m_X against which the \\Lambda_c is recoiling almost always satisfies m_X\\agt m_{\\Xi_c}. This fact leads us to examine the hypothesis that the production of charmed baryons in B decays is in fact dominated by the underlying transition b\\to c\\bar cs, and is seen primarily in modes with two charmed baryons in the final state. We propose a number of tests of this hypothesis. If this mechanism is indeed important in baryon production, then there are interesting consequences and applications, including potentially important implications for the ``charm deficit'' in B decays.
Spectrum and Structure of Excited Baryons with CLAS
Burkert, Volker D.
2017-01-01
In this contribution I discuss recent results in light quark baryon spectroscopy involving CLAS data and higher level analysis results from the partial wave analysis by the Bonn-Gatchina group. New baryon states were discovered largely based on the open strangeness production channels γp → K+Λ and γp → K+Σ0. The data illustrate the great potential of the kaon-hyperon channel in the discovery of higher mass baryon resonances in s-channel production. Other channels with discovery potential, such as γp → pω and γp → ϕp are also discussed. In the second part I will demonstrate on data the sensitivity of meson electroproduction to expose the active degrees of freedom underlying resonance transitions as a function of the probed distance scale. For several of the prominent excited states in the lower mass range the short distance behavior is described by a core of three dressed-quarks with running quark mass, and meson-baryon contributions make up significant parts of the excitation strength at large distances. Finally, I give an outlook of baryon resonance physics at the 12 GeV CEBAF electron accelerator. Talk presented at the CRC-16 Symposium, Bonn University, June 6-9, 2016.
Spectrum and Structure of Excited Baryons with CLAS*
Directory of Open Access Journals (Sweden)
Burkert Volker D.
2017-01-01
Full Text Available In this contribution I discuss recent results in light quark baryon spectroscopy involving CLAS data and higher level analysis results from the partial wave analysis by the Bonn-Gatchina group. New baryon states were discovered largely based on the open strangeness production channels γp → K+Λ and γp → K+Σ0. The data illustrate the great potential of the kaon-hyperon channel in the discovery of higher mass baryon resonances in s-channel production. Other channels with discovery potential, such as γp → pω and γp → ϕp are also discussed. In the second part I will demonstrate on data the sensitivity of meson electroproduction to expose the active degrees of freedom underlying resonance transitions as a function of the probed distance scale. For several of the prominent excited states in the lower mass range the short distance behavior is described by a core of three dressed-quarks with running quark mass, and meson-baryon contributions make up significant parts of the excitation strength at large distances. Finally, I give an outlook of baryon resonance physics at the 12 GeV CEBAF electron accelerator.
The segregation of baryons and dark matter during halo assembly
Liao, Shihong; Frenk, Carlos S; Guo, Qi; Wang, Jie
2016-01-01
The standard galaxy formation theory assumes that baryons and dark matter are initially well-mixed before becoming segregated due to radiative cooling. We use non-radiative hydrodynamical simulations to explicitly examine this assumption and find that baryons and dark matter can also be segregated during the build-up of the halo. As a result, baryons in many haloes do not originate from the same Lagrangian region as the dark matter. When using the fraction of corresponding dark matter and gas particles in the initial conditions (the "paired fraction") as a proxy of the dark matter and gas segregation strength of a halo, on average about $25$ percent of the baryonic and dark matter of the final halo are segregated in the initial conditions. A consequence of this effect is that the baryons and dark matter of the same halo initially experience different tidal torques and thus their angular momentum vectors are often misaligned. This is at odds with the assumption of the standard galaxy formation model, and chall...
Decays of J/psi (3100) to baryon final states
Energy Technology Data Exchange (ETDEWEB)
Eaton, M.W.
1982-05-01
We present results for the decays of psi(3100) into baryon and hyperon final states. The sample studied here consists of 1.3 million produced psi decays. The decays into nonstrange baryons agree well with currently established results, but with better statistics. In addition, significant resonance formation in multibody final states is observed. The decay psi ..-->.. anti pp..gamma.., the first direct photon decay of the psi involving baryons in the final state, is presented and the theoretical implications of the decays are briefly explored. Several new decays of the psi involving strange baryons are explored, including the first observations of three body final states involving hyperons. The I-spin symmetry of the strong decay psi ..-->.. baryons has clearly been observed. The reduced matrix elements for psi ..-->.. B anti B are presented for final states of different SU(3) content. The B/sub 8/ anti B/sub 8/ results are in excellent agreement with the psi being an SU(3) singlet as are the results for psi ..-->.. B/sub 10/ anti B/sub 10/. We present the first evidence for the SU(3) violating decays of the type psi ..-->.. B/sub 8/ anti B/sub 10/ + c.c.. Angular distributions for psi ..-->.. B/sub 8/ anti B/sub 8/ are presented and compared with theoretical predictions. Statistics are limited, but the data tends to prefer other than a 1 + Cos/sup 2/theta distribution.
Oscillating Permanent Magnets.
Michaelis, M. M.; Haines, C. M.
1989-01-01
Describes several ways to partially levitate permanent magnets. Computes field line geometries and oscillation frequencies. Provides several diagrams illustrating the mechanism of the oscillation. (YP)
Solar neutrinos: Oscillations or No-oscillations?
Smirnov, A Yu
2016-01-01
The Nobel prize in physics 2015 has been awarded "... for the discovery of neutrino oscillations which show that neutrinos have mass". While SuperKamiokande (SK), indeed, has discovered oscillations, SNO observed effect of the adiabatic (almost non-oscillatory) flavor conversion of neutrinos in the matter of the Sun. Oscillations are irrelevant for solar neutrinos apart from small $\
Non-singlet Baryons in Less Supersymmetric Backgrounds
Giataganas, Dimitrios; Picos, Marco; Siampos, Konstadinos
2012-01-01
We analyze the holographic description of non-singlet baryons in various backgrounds with reduced supersymmetries and/or confining. We show that they exist in all AdS_5xY_5 backgrounds with Y_5 an Einstein manifold bearing five form flux, for a number of quarks 5N/8< k< N, independently on the supersymmetries preserved. This result still holds for gamma_i deformations. In the confining Maldacena-Nunez background non-singlet baryons also exist, although in this case the interval for the number of quarks is reduced as compared to the conformal case. We generalize these configurations to include a non-vanishing magnetic flux such that a complementary microscopical description can be given in terms of lower dimensional branes expanding into fuzzy baryons. This description is a first step towards exploring the finite 't Hooft coupling region.
Measurement of the Lifetime of b-baryons
Abreu, P; Adye, T; Adzic, P; Albrecht, Z; Alderweireld, T; Alekseev, G D; Alemany, R; Allmendinger, T; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Anassontzis, E G; Andersson, P; Andreazza, A; Andringa, S; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbiellini, Guido; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Belous, K S; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Bizouard, M A; Bloch, D; Blom, H M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Boyko, I; Bozovic, I; Bozzo, M; Branchini, P; Brenke, T; Brenner, R A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camporesi, T; Canale, V; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Chapkin, M M; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cieslik, K; Collins, P; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crépé, S; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Dris, M; Duperrin, A; Durand, J D; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Ellert, M; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Fayot, J; Feindt, Michael; Fenyuk, A; Ferrari, P; Ferrer, A; Ferrer-Ribas, E; Fichet, S; Firestone, A; Flagmeyer, U; Föth, H; Fokitis, E; Fontanelli, F; Franek, B J; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gamblin, S; Gandelman, M; García, C; Gaspar, C; Gaspar, M; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Ghodbane, N; Gil, I; Glege, F; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; González-Caballero, I; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Grahl, J; Graziani, E; Green, C; Grimm, H J; Gris, P; Grosdidier, G; Grzelak, K; Günther, M; Guy, J; Hahn, F; Hahn, S; Haider, S; Hallgren, A; Hamacher, K; Hansen, J; Harris, F J; Hedberg, V; Heising, S; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, S O; Holt, P J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hughes, G J; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, P E; Joram, C; Juillot, P; Kapusta, F; Karafasoulis, K; Katsanevas, S; Katsoufis, E C; Keränen, R; Kersevan, Borut P; Khomenko, B A; Khovanskii, N N; Kiiskinen, A P; King, B J; Kinvig, A; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kriznic, E; Krstic, J; Krumshtein, Z; Kubinec, P; Kurowska, J; Kurvinen, K L; Lamsa, J; Lane, D W; Langefeld, P; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Leinonen, L; Leisos, A; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Lethuillier, M; Libby, J; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; Lopes, J H; López, J M; López-Fernandez, R; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Mahon, J R; Maio, A; Malek, A; Malmgren, T G M; Malychev, V; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, F; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Meroni, C; Meyer, W T; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Moch, M; Møller, R; Mönig, K; Monge, M R; Moreau, X; Morettini, P; Morton, G A; Müller, U; Münich, K; Mulders, M; Mulet-Marquis, C; Muresan, R; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Némécek, S; Neufeld, N; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nikolenko, M; Nomokonov, V P; Normand, Ainsley; Nygren, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganoni, M; Paiano, S; Pain, R; Paiva, R; Palacios, J; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Pegoraro, M; Peralta, L; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rakoczy, D; Ratoff, P N; Read, A L; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Røhne, O M; Romero, A; Ronchese, P; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Royon, C; Ruhlmann-Kleider, V; Ruiz, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sampsonidis, D; Sannino, M; Schneider, H; Schwemling, P; Schwickerath, U; Schyns, M A E; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Sekulin, R L; Shellard, R C; Sheridan, A; Siebel, M; Simard, L C; Simonetto, F; Sissakian, A N; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sopczak, André; Sosnowski, R; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stampfer, D; Stanescu, C; Stanic, S; Stevenson, K; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tegenfeldt, F; Terranova, F; Thomas, J; Timmermans, J; Tinti, N; Tkatchev, L G; Todorova-Nová, S; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Van Lysebetten, A; Van Vulpen, I B; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Verzi, V; Vilanova, D; Vitale, L; Vlasov, E; Vodopyanov, A S; Vollmer, C F; Voulgaris, G; Vrba, V; Wahlen, H; Walck, C; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G R; Winter, M; Witek, M; Wolf, G; Yi, J; Yushchenko, O P; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zucchelli, G C; Zumerle, G
1999-01-01
The average lifetime of weakly decaying $b$-baryons was studied using 3.6 million $Z^0$ hadronic decays collected by the DELPHI detector at LEP. The measurement of the proper decay time distribution of secondary vertices was used on three complementary samples. The first sample consisted of events with a fully reconstructed $\\Lambda_c^+$ and an opposite charge lepton, or an oppositely charged lepton pair accompanied by a $\\Lambda^0$. The other two samples were more inclusive, where $b$-baryon semileptonic decays were recognized by the presence of either a proton identified by the RICH detector or a $\\Lambda^0$ and a lepton of charge opposite to that of the proton. The combined result was: \\begin{eqnarray*} \\tau(b\\mathrm{-baryon}) = 1.14\\pm0.08 \\; (stat)\\pm0.04 \\; (syst) \\; \\mathrm{ps} \\; . \\end{eqnarray*} It updates and replaces all previous results published by the DELPHI collaboration.
Accurate initial conditions in mixed Dark Matter--Baryon simulations
Valkenburg, Wessel
2016-01-01
We quantify the error in the results of mixed baryon--dark-matter hydrodynamic simulations, stemming from outdated approximations for the generation of initial conditions. The error at redshift 0 in contemporary large simulations, is of the order of few to ten percent in the power spectra of baryons and dark matter, and their combined total-matter power spectrum. After describing how to properly assign initial displacements and peculiar velocities to multiple species, we review several approximations: (1) {using the total-matter power spectrum to compute displacements and peculiar velocities of both fluids}, (2) scaling the linear redshift-zero power spectrum back to the initial power spectrum using the Newtonian growth factor ignoring homogeneous radiation, (3) using longitudinal-gauge velocities with synchronous-gauge densities, and (4) ignoring the phase-difference in the Fourier modes for the offset baryon grid, relative to the dark-matter grid. Three of these approximations do not take into account that ...
Baryons as relativistic three-quark bound states
Eichmann, Gernot; Williams, Richard; Alkofer, Reinhard; Fischer, Christian S
2016-01-01
We review the spectrum and electromagnetic properties of baryons described as relativistic three-quark bound states within QCD. The composite nature of baryons results in a rich excitation spectrum, whilst leading to highly non-trivial structural properties explored by the coupling to external (electromagnetic and other) currents. Both present many unsolved problems despite decades of experimental and theoretical research. We discuss the progress in these fields from a theoretical perspective, focusing on nonperturbative QCD as encoded in the functional approach via Dyson-Schwinger and Bethe-Salpeter equations. We give a systematic overview as to how results are obtained in this framework and explain technical connections to lattice QCD. We also discuss the mutual relations to the quark model, which still serves as a reference to distinguish 'expected' from 'unexpected' physics. We confront recent results on the spectrum of non-strange and strange baryons, their form factors and the issues of two-photon proce...
Accounting for Baryons in Cosmological Constraints from Cosmic Shear
Zentner, Andrew R; Dodelson, Scott; Eifler, Tim; Krause, Elisabeth; Hearin, Andrew P
2012-01-01
One of the most pernicious theoretical systematics facing upcoming gravitational lensing surveys is the uncertainty introduced by the effects of baryons on the power spectrum of the convergence field. One method that has been proposed to account for these effects is to allow several additional parameters (that characterize dark matter halos) to vary and to fit lensing data to these halo parameters concurrently with the standard set of cosmological parameters. We test this method. In particular, we use this technique to model convergence power spectrum predictions from a set of cosmological simulations. We estimate biases in dark energy equation of state parameters that would be incurred if one were to fit the spectra predicted by the simulations either with no model for baryons, or with the proposed method. We show that neglecting baryonic effect leads to biases in dark energy parameters that are several times the statistical errors for a survey like the Dark Energy Survey. The proposed method to correct for ...
Observation of the sigma_b baryons at CDF
Energy Technology Data Exchange (ETDEWEB)
Pursley, Jennifer M.; /Johns Hopkins U.
2007-03-01
We present a measurement of four new bottom baryons in proton-antiproton collisions with a center of mass energy of 1.96 TeV. Using 1.1 fb{sup -1} of data collected by the CDF II detector, we observe four {Lambda}{sup 0}{sub b}{pi}{+-} resonances in the fully reconstructed decay mode {Lambda}{sup 0}{sub b} {yields} {Lambda}{sup +}{sub c}{pi}{sup -}, where {Lambda}{sup +}{sub c} {yields} pK{sup -}{pi}{sup +}. The probability for the background to produce a similar or larger signal is less than 8.3 x 10{sup -8}, corresponding to a significance of greater than 5.2 {sigma}. We interpret these baryons as the {Sigma}{sub b}{sup (*){+-}} baryons.
Study of Baryon Spectroscopy Using a New Potential Form
Directory of Open Access Journals (Sweden)
L. I. Abou-Salem
2014-01-01
Full Text Available In the present work, the nonrelativistic quark model is applied to study baryon systems, where the constituent quarks are bound by a suitable hyper central potential. We proposed a new phenomenological form of the interaction potential, digamma-type potential. Using the Jacobi coordinates, the three-body wave equation is solved numerically to calculate the resonance states of the N, Δ, Λ, and Σ baryon systems. The present model contains only two adjustable parameters in addition to the quark masses. Our theoretical calculations are compared to the available experimental data and Cornell potential results. The description of the spectrum shows that the ground states of the considered light and strange baryon spectra are in general well reproduced.
Interactions between Octet Baryons in the SU_6 Quark model
Fujiwara, Y; Nakamoto, C; Suzuki, Y
2001-01-01
The baryon-baryon interactions for the complete baryon octet (B_8) are investigated in a unified framework of the resonating-group method, in which the spin-flavor SU_6 quark-model wave functions are employed. Model parameters are determined to reproduce properties of the nucleon-nucleon system and the low-energy cross section data for the hyperon-nucleon interaction. We then proceed to explore B_8 B_8 interactions in the strangeness S=-2, -3 and -4 sectors. The S-wave phase-shift behavior and total cross sections are systematically understood by 1) the spin-flavor SU_6 symmetry, 2) the special role of the pion exchange, and 3) the flavor symmetry breaking.
Baryon stopping and saturation physics at RHIC and LHC
Mehtar-Tani, Yacine
2009-01-01
We investigate baryon transport in relativistic heavy-ion collisions at energies reached at the CERN Super Proton Synchrotron, BNL Relativistic Heavy-Ion Collider (RHIC), and CERN LHC in the model of saturation. An analytical scaling law is derived within the color glass condensate framework based on small-coupling QCD. Transverse momentum spectra, net-baryon rapidity distributions and their energy, mass and centrality dependences are well described. In a comparison with RHIC data in Au + Au collisions at sqrt (s_NN) = 62.4 GeV and 200 GeV, the gradual approach to the gluon saturation regime is investigated, and limits for the saturation-scale exponent are determined. Predictions for net-baryon rapidity spectra and the mean rapidity loss in central Pb + Pb collisions at LHC energies of sqrt (s_NN) = 5.52 TeV are made.
Measurement of b-Baryons with the CDF II detector
Energy Technology Data Exchange (ETDEWEB)
Heuser, Joachim; /Karlsruhe U., EKP
2007-10-01
We report the observation of new bottom baryon states. The most recent result is the observation of the baryon {Xi}{sub b}{sup -} through the decay {Xi}{sub b}{sup -} {yields} J/{psi}{Xi}{sup -}. The significance of the signal corresponds to 7.7{sigma} and the {Xi}{sub b}{sup -} mass is measured to be 5792.9{+-}2.5(stat.){+-}1.7(syst.) MeV/c{sup 2}. In addition we observe four resonances in the {Lambda}{sub b}{sup 0}{pi}{sup {+-}} spectra, consistent with the bottom baryons {Sigma}{sub b}{sup (*){+-}}. All observations are in agreement with theoretical expectations.
Baryon electric dipole moments from strong CP violation
Guo, Feng-Kun; Meißner, Ulf-G.
2012-12-01
The electric dipole form factors and moments of the ground state baryons are calculated in chiral perturbation theory at next-to-leading order. We show that the baryon electric dipole form factors at this order depend only on two combinations of low-energy constants. We also derive various relations that are free of unknown low-energy constants. We use recent lattice QCD data to calculate all baryon EDMs. In particular, we find d n = -2 .9 ± 0 .9 and d p = 1 .1 ± 1 .1 in units of 10-16 e θ 0 cm. Finite volume corrections to the electric dipole moments are also worked out. We show that for a precision extraction from lattice QCD data, the next-to-leading order terms have to be accounted for.
Moduli induced cogenesis of baryon asymmetry and dark matter
Dhuria, Mansi; Sarkar, Utpal
2015-01-01
We study a cogenesis mechanism in which the observed baryon asymmetry of the universe and the dark matter abundance can be produced simultaneously at low reheating temperature without violating baryon number in the fundamental vertex. In particular, we consider a model which could be realized in the context of type IIB large volume string compactifications. The matter superfields in this model include additional pairs of color triplet and singlet superfields in addition to the Minimal Supersymmetric Standard Model (MSSM) superfields. Assuming that the mass of the additional singlet fermions is O(GeV) and color triplet fermions is O(TeV), we show that the modulus dominantly decays into the additional color triplet superfields. After soft supersymmetry (SUSY) breaking, the lightest eigenstate of scalar component of color triplet superfield further decays into fermionic component of singlet superfield and quarks without violating baryon number. Assuming R-parity conservation, it follows that the singlet superfie...
Faessler, A; Holstein, Barry R; Lyubovitskij, V E; Nicmorus, D; Pumsa-ard, K; Faessler, Amand; Gutsche, Thomas; Holstein, Barry R.; Lyubovitskij, Valery E.; Nicmorus, Diana; Pumsa-ard, Kem
2006-01-01
We calculate magnetic moments of light baryons and N -> Delta gamma transition characteristics using a manifestly Lorentz covariant chiral quark approach for the study of baryons as bound states of constituent quarks dressed by a cloud of pseudoscalar mesons.
Magnetic Moments of Baryons containing all heavy quarks in Quark-Diquark Model
Thakkar, Kaushal; Vinodkumar, P C
2016-01-01
The triply heavy flavour baryons are studied using the Quark-diquark description of the three-body system. The confinement potential for present study of triply heavy flavour baryons is assumed as coulomb plus power potential with power index $\
Study of Doubly Heavy Baryon Spectrum via QCD Sum Rules
Institute of Scientific and Technical Information of China (English)
TANG Liang; YUAN Xu-Hao; QIAO Cong-Feng; LI Xue-Qian
2012-01-01
In this work, we calculate the mass spectrum of doubly heavy baryons with the diquaxk model in terms of the QCD sum rules. The interpolating currents are composed of a heavy diquaxk field and a light quark field. Contributions of the operators up to dimension six are taken into account in the operator product expansion. Within a reasonable error tolerance, our numerical results axe compatible with other theoretical predictions. This indicates that the diquaxk picture reflects the reality and is applicable to the study of doubly heavy baryons.
Baryon inhomogeneities in a charged quark gluon plasma
Energy Technology Data Exchange (ETDEWEB)
Ray, Avijeet [Indian Institute of Technology Roorkee, Uttarakhand, 247667 (India); Sanyal, Soma, E-mail: sossp@uohyd.ernet.in [School of Physics, University of Hyderabad, Gachibowli, Hyderabad, 500046 (India)
2013-10-07
We study the generation of baryon inhomogeneities in regions of the quark gluon plasma which have a charge imbalance. We find that the overdensity in the baryon lumps for positively charged particles is different from the overdensity due to the negatively charged particles. Since quarks are charged particles, the probability of forming neutrons or protons in the lumps would thus be changed. The probability of forming hadrons having quarks of the same charges would be enhanced. This might have interesting consequences for the inhomogeneous nucleosynthesis calculations.
Transition magnetic moments between negative parity heavy baryons
Aliev, T M; Savci, M
2015-01-01
The transition magnetic moments between negative parity, spin-1/2 heavy baryons are studied in framework of the light cone QCD sum rules. By constructing the sum rules for different Lorentz structures, the unwanted contributions coming from negative (positive) to positive (negative) parity transitions are removed. It is found that the magnetic moments between neutral negative parity heavy $\\Xi_Q^{\\prime 0}$ and $\\Xi_Q^0$ baryons are very small. Magnetic moments of the $\\Sigma_Q \\to \\Lambda_Q$ and $ \\Xi_Q^{\\prime \\pm} \\to \\Xi_Q^\\pm$ transitions are quite large and can be measured in further experiments.
Baryon Wave Functions in Covariant Relativistic Quark Models
Dillig, M
2002-01-01
We derive covariant baryon wave functions for arbitrary Lorentz boosts. Modeling baryons as quark-diquark systems, we reduce their manifestly covariant Bethe-Salpeter equation to a covariant 3-dimensional form by projecting on the relative quark-diquark energy. Guided by a phenomenological multigluon exchange representation of a covariant confining kernel, we derive for practical applications explicit solutions for harmonic confinement and for the MIT Bag Model. We briefly comment on the interplay of boosts and center-of-mass corrections in relativistic quark models.
Baryon Asymmetry, Neutrino Mixing and Supersymmetric SO(10) Unification
Plümacher, Michael
1998-01-01
The baryon asymmetry of the universe can be explained by the out-of-equilibrium decays of heavy right-handed neutrinos. We analyse this mechanism in the framework of a supersymmetric extension of the Standard Model and show that lepton number violating scatterings are indispensable for baryogenesis, even though they may wash-out a generated asymmetry. By assuming a similar pattern of mixings and masses for neutrinos and up-type quarks, as suggested by SO(10) unification, we can generate the observed baryon asymmetry without any fine tuning, if (B-L) is broken at the unification scale preferred by the MSW solution to the solar neutrino deficit.
On Exotic Systems of Baryons in Chiral Soliton Models
Kopeliovich, Vladimir
2016-01-01
The role of zero mode quantum corrections to the energy of baryonic systems with exotic quantum numbers (strangeness) is discussed. A simple expression for the contribution depending on strange inertia is obtained in the $SU(3)-$collective coordinate quantization approach, and it is shown that this correction stabilizes the systems the stronger the greater their baryon number is. Furthemore, systems are considered which could be interpreted in the quark model language as containing additional $q\\bar q-$pairs. It is argued that a strange skyrmion crystal should have additional binding in comparison with the $SU(2)-$quantized neutron crystal.
Baryon symmetric big-bang cosmology. [matter-antimatter symmetry
Stecker, F. W.
1978-01-01
The framework of baryon-symmetric big-bang cosmology offers the greatest potential for deducing the evolution of the universe as a consequence of physical laws and processes with the minimum number of arbitrary assumptions as to initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the universe and how galaxies and galaxy clusters are formed, and also provides the only acceptable explanation at present for the origin of the cosmic gamma ray background radiation.
Diquark correlations in baryons on the lattice with overlap quarks
Energy Technology Data Exchange (ETDEWEB)
Babich, R.; Howard, J.; Rebbi, C. [Boston Univ., MA (United States). Dept. of Physics; Garron, N. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hoelbling, C. [Wuppertal Univ. (Gesamthochschule) (Germany). Fachbereich Physik; Lellouch, L. [CNRS Luminy, Marseille (France). Centre de Physique Theorique]|[Wuppertal Univ. (Gesamthochschule) (Germany). Fachbereich Physik
2007-01-15
We evaluate baryon wave functions in both the Coulomb and Landau gauge in lattice QCD. These are constructed from quark propagators calculated with the overlap Dirac operator on quenched gauge configurations at {beta}=6. By comparing baryon states that differ in their diquark content, we find evidence for enhanced correlation in the scalar diquark channel, as favored by quark models. We also summarize earlier results for diquark masses in the Landau gauge, casting them in a form more easily compared with subsequent studies. (orig.)
Effect of higher orbital angular momenta in the baryon spectrum
Garcilazo, H; Fernández, F
2001-01-01
We have performed a Faddeev calculation of the baryon spectrum for the chiral constituent quark model including higher orbital angular momentum states. We have found that the effect of these states is important, although a description of the baryon spectrum of the same quality as the one given by including only the lowest-order configurations can be obtained. We have studied the effect of the pseudoscalar quark-quark interaction on the relative position of the positive- and negative-parity excitations of the nucleon as well as the effect of varying the strength of the color-magnetic interaction.
Oscillations and waves in solar spicules
Zaqarashvili, T V
2009-01-01
Since their discovery, spicules have attracted increased attention as energy/mass bridges between the dense and dynamic photosphere and the tenuous hot solar corona. Mechanical energy of photospheric random and coherent motions can be guided by magnetic field lines, spanning from the interior to the upper parts of the solar atmosphere, in the form of waves and oscillations. Since spicules are one of the most pronounced features of the chromosphere, the energy transport they participate in can be traced by the observations of their oscillatory motions. Oscillations in spicules have been observed for a long time. However the recent high-resolutions and high-cadence space and ground based facilities with superb spatial, temporal and spectral capacities brought new aspects in the research of spicule dynamics. Here we review the progress made in imaging and spectroscopic observations of waves and oscillations in spicules. The observations are accompanied by a discussion on theoretical modelling and interpretations...
Slepian, Zachary; Blazek, Jonathan A; Brownstein, Joel R; Chuang, Chia-Hsun; Gil-Marín, Héctor; Ho, Shirley; Kitaura, Francisco-Shu; McEwen, Joseph E; Percival, Will J; Ross, Ashley J; Rossi, Graziano; Seo, Hee-Jong; Slosar, Anže; Vargas-Magaña, Mariana
2016-01-01
We search for a galaxy clustering bias due to a modulation of galaxy number with the baryon-dark matter relative velocity resulting from recombination-era physics. We find no detected signal and place the constraint $b_v < 0.01$ on the relative velocity bias for the CMASS galaxies. This bias is an important potential systematic of Baryon Acoustic Oscillation (BAO) method measurements of the cosmic distance scale using the 2-point clustering. Our limit on the relative velocity bias indicates a systematic shift of no more than $0.3\\%$ rms in the distance scale inferred from the BAO feature in the BOSS 2-point clustering, well below the $1\\%$ statistical error of this measurement. This constraint is the most stringent currently available and has important implications for the ability of upcoming large-scale structure surveys such as DESI to self-protect against the relative velocity as a possible systematic.
Magnetic moments of heavy baryons in the relativistic three-quark model
Faessler, A; Ivanov, M A; Körner, J G; Lyubovitskij, V E; Nicmorus, D; Pumsa-ard, K; Faessler, Amand; Gutsche, Th.
2006-01-01
The magnetic moments of ground state single, double and triple heavy baryons containing charm or bottom quarks are calculated in a relativistic three-quark model, which, in the heavy quark limit, is consistent with Heavy Quark Effective Theory and Heavy Hadron Chiral Perturbation Theory. The internal quark structure of baryons is modeled by baryonic three-quark currents with a spin-flavor structure patterned according to standard covariant baryonic wave functions and currents used in QCD sum rule calculations.
Li, Hao-Song; Chen, Xiao-Lin; Deng, Wei-Zhen; Zhu, Shi-Lin
2016-01-01
We have systematically investigated the magnetic moments and magnetic form factors of the decuplet baryons to the next-to-next-leading order in the framework of the heavy baryon chiral perturbation theory. Our calculation includes the contributions from both the intermediate decuplet and octet baryon states in the loops. We also calculate the charge and magnetic dipole form factors of the decuplet baryons. Our results may be useful to the chiral extrapolation of the lattice simulations of the decuplet electromagnetic properties.
Oscillations of Eccentric Pulsons
DEFF Research Database (Denmark)
Christiansen, Peter Leth; Groenbech-Jensen, Niels; Lomdahl, Peter;
1997-01-01
Perturbation theory for elliptic pulsons is developed and predicts pulson and eccentricity oscillations. The pulson oscillation period is predicted qualitatively correct.......Perturbation theory for elliptic pulsons is developed and predicts pulson and eccentricity oscillations. The pulson oscillation period is predicted qualitatively correct....
On the quark-mass dependence of baryon ground-state masses
Energy Technology Data Exchange (ETDEWEB)
Semke, Alexander
2010-02-17
Baryon masses of the flavour SU(3) octet and decuplet baryons are calculated in the framework of the Chiral Perturbations Theory - the effective field theory of the strong interaction. The chiral extrapolation to the higher meson (quark) masses is carried out. The comparison with the recent results on the baryon masses from lattice calculations are presented. (orig.)
Leptogenesis via axion oscillations after inflation
Kusenko, Alexander; Yanagida, Tsutomu T
2014-01-01
The evolution of an axionic field after inflation offers an explanation for the matter-antimatter asymmetry of the universe. During inflation, light scalar fields, including axions expected to arise from string theory and in various field-theoretic models, develop large expectation values. These fields relax to the minima of their effective potentials during or after reheating. An oscillating axion coupled to the electroweak gauge fields generates an effective chemical potential for the fermion number, which, in the presence of lepton number-violating processes, generates a lepton asymmetry that is partly converted to a baryon asymmetry by sphalerons. The observed matter-antimatter asymmetry can be explained in a broad range of parameter values with the reheating temperatures being at least of order 10^12 GeV, and for all right-handed neutrino masses close to the scale of grand unification. Our mechanism is hence complementary to thermal leptogenesis with respect to the range of allowed parameter values.
Keselman, Ariel
2016-01-01
NoAM for "No Action Method" is a framework for reconstructing the past orbits of observed tracers of the large scale mass density field. It seeks exact solutions of the equations of motion (EoM), satisfying initial homogeneity and the final observed particle (tracer) positions. The solutions are found iteratively reaching a specified tolerance defined as the RMS of the distance between reconstructed and observed positions. Starting from a guess for the initial conditions, NoAM advances particles using standard N-body techniques for solving the EoM. Alternatively, the EoM can be replaced by any approximation such as Zel'dovich and second order perturbation theory (2LPT). NoAM is suitable for billions of particles and can easily handle non-regular volumes, redshift space, and other constraints. We implement NoAM to systematically compare Zel'dovich, 2LPT, and N-body dynamics over diverse configurations ranging from idealized high-res periodic simulation box to realistic galaxy mocks. Our findings are (i) Non-li...
Spectroscopic Dosimeter Project
National Aeronautics and Space Administration — Analysis of Phase I test data demonstrates that the Photogenics Spectroscopic Dosimeter will detect neutron energies from 0.8 up to 600 MeV. The detector...
Three Baryon Interaction Generated by Determinant Interaction of Quarks
Ohnishi, Akira; Morita, Kenji
2016-01-01
We discuss the three-baryon interaction generated by the determinant interaction of quarks, known as the Kobayashi-Maskawa-'t Hooft (KMT) interaction. The expectation value of the KMT interaction operator is calculated in fully-antisymmetrized quark-cluster model wave functions for one-, two- and three-octet baryon states. The three-baryon potential from the KMT interaction is found to be repulsive for $NN\\Lambda$ and $N\\Lambda\\Lambda$ systems, while it is zero for the $NNN$ system. The strength and range of the three-baryon potential are found to be comparable to those for the $NNN$ three-body potential obtained in lattice QCD simulations. The contribution to the $\\Lambda$ single particle potential in nuclear matter is found to be 0.28 MeV and 0.73 MeV in neutron matter and symmetric nuclear matter at normal nuclear density, respectively. These repulsive forces are not enough to solve the hyperon puzzle, but may be measured in high-precision hyperisotope experiments.
The baryon fraction in hydrodynamical simulations of galaxy clusters
Ettori, S; Borgani, S; Murante, G
2006-01-01
We study the baryon mass fraction in a set of hydrodynamical simulations of galaxy clusters performed using the Tree+SPH code GADGET-2. We investigate the dependence of the baryon fraction upon the radiative cooling, star formation, feedback through galactic winds, conduction and redshift. Both the cold stellar component and the hot X-ray emitting gas have narrow distributions that, at large cluster-centric distances r>R500, are nearly independent of the physics included in the simulations. Only the non-radiative runs reproduce the gas fraction inferred from observations of the inner regions (r ~ R2500) of massive clusters. When cooling is turned on, the excess star formation is mitigated by the action of galactic winds, but yet not by the amount required by observational data. The baryon fraction within a fixed overdensity increases slightly with redshift, independent of the physical processes involved in the accumulation of baryons in the cluster potential well. In runs with cooling and feedback, the increa...
Baryomorphosis: Relating the Baryon Asymmetry to the "WIMP Miracle"
McDonald, John
2010-01-01
We present a generic framework, "baryomorphosis", which modifies the baryon asymmetry to be naturally of the order of a typical thermal relic WIMP density. We consider a simple scalar-based model to show how this is possible. This model introduces a sector in which a large initial baryon asymmetry is injected into particles ("annihilons"), phi_{B}, phi_{B, hat}, of mass ~ 100 GeV - 1 TeV. phi_{B}-phi_{B, hat} annihilations convert the initial phi_{B}, phi_{B, hat} asymmetry to a final asymmetry with a thermal relic WIMP-like density. This subsequently decays to a conventional baryon asymmetry whose magnitude is naturally related to the density of thermal relic WIMP dark matter. In this way the two coincidences of baryons and dark matter i.e. why their densities are similar to each other and why they are both similar to a WIMP thermal relic density (the "WIMP miracle"), may be understood. The model can be tested by the production of annihilons at colliders.
First Observation of a Baryonic B-c(+) Decay
Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M. -O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjornstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; van den Brand, J.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Brown, H.; Bursche, A.; Busetto, G.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Perez, D. Campora; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Akiba, K. Carvalho; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S. -F.; Chiapolini, N.; Chrzaszcz, M.; Ciba, K.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cojocariu, L.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Di Canto, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. -M.; Evans, T.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R. F.; Ferguson, D.; Fernandez Albor, V.; Rodrigues, F. Ferreira; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Pardinas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gavrilov, G.; Geraci, A.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Gandara, M. Grabalosa; Graciani Diaz, R.; Cardoso, L. A. Granado; Grauges, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hunt, P.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kaballo, M.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J. -P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leo, S.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lopez-March, N.; Lowdon, P.; Lu, H.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Maerki, R.; Marks, J.; Martellotti, G.; Martens, A.; Sanchez, A. Martin; Martinelli, M.; Santos, D. Martinez; Martinez Vidal, F.; Tostes, D. Martins; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; Mcnab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. -N.; Moggi, N.; Rodriguez, J. Molina; Monteil, S.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M. J.; Moron, J.; Morris, A. -B.; Mountain, R.; Muheim, F.; Mueller, K.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, G.; Orlandea, M.; Goicochea, J. M. Otalora; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pazos Alvarez, A.; Pearce, A.; Pellegrino, A.; Altarelli, M. Pepe; Perazzini, S.; Perez Trigo, E.; Perret, P.; Perrin-Terrin, M.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poluektov, A.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Romero, D. A. Roa; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Silva, J. J. Saborido; Sagidova, N.; Sail, P.; Saitta, B.; Guimaraes, V. Salustino; Mayordomo, C. Sanchez; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrie, M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. -H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Seco, M.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; De Paula, B. Souza; Spaan, B.; Sparkes, A.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Subbiah, V. K.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szilard, D.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Vazquez Regueiro, P.; Sierra, C. Vzquez; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; Voss, H.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wicht, J.; Wiedner, D.; Wilkinson, G.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wu, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zvyagin, A.
2014-01-01
A baryonic decay of the B-c(+) meson, B-c(+) -> J/psi p (p) over bar pi(+) is observed for the first time, with a significance of 7.3 standard deviations, in pp collision data collected with the LHCb detector and corresponding to an integrated luminosity of 3.0 fb(-1) taken at center-of-mass energie
The inner regions of disk galaxies: a constant baryonic fraction?
Lelli, Federico
2014-01-01
For disk galaxies (spirals and irregulars), the inner circular-velocity gradient (inner steepness of the rotation curve) correlates with the central surface brightness with a slope of ~0.5. This implies that the central dynamical mass density scales almost linearly with the central baryonic density. Here I show that this empirical relation is consistent with a simple model where the central baryonic fraction f_bar(0) is fixed to 1 (no dark matter) and the observed scatter is due to differences in the baryonic mass-to-light ratio M_bar/L (ranging from 1 to 3 in the R-band) and in the characteristic thickness of the central stellar component dz (ranging from 100 to 500 pc). Models with lower baryonic fractions are possible, although they require some fine-tuning in the values of M_bar/L and dz. Regardless of the actual value of f_bar(0), the fact that different types of galaxies do not show strong variations in f_bar(0) is surprising, and may represent a challenge for models of galaxy formation in a LCDM cosmol...
Pion photo- and electroproduction in relativistic baryon ChPT
Directory of Open Access Journals (Sweden)
Tiator Lothar
2014-06-01
Full Text Available We present a calculation of pion photo- and electroproduction in manifestly Lorentz-invariant baryon chiral perturbation theory up to and including order q4. We fix the low-energy constants by fitting experimental data in all available reaction channels. Our results can be accessed via a web interface, the so-called chiral MAID.
Observation of Two New Xi(-)(b) Baryon Resonances
Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M. -O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjornstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Akiba, K. Carvalho; Casanova Mohr, R. C. M.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S. -F.; Chiapolini, N.; Chrzaszcz, M.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A. C.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Dean, C. -T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Domenico, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. -M.; Evans, T.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Pardinas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gastaldi, U.; Gauld, R.; Gavardi, L.; Gazzoni, U.; Geraci, A.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Gandara, M. Grabalosa; Graciani Diaz, R.; Cardoso, L. A. Granado; Grauges, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griftith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; Van Leerdam, J.; Lees, J. -P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lowdon, P.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Benito, C. Mann; Marino, P.; Maerki, R.; Marks, J.; Martellotti, G.; Martinelli, M.; Santos, D. Martinez; Vidal, F. Martinez; Martin Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. -N.; Moggi, N.; Rodriguez, J. Molina; Monteil, S.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M. J.; Moron, J.; Morris, A. -B.; Mountain, R.; Muheim, F.; Mueller, K.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obratsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Orlandea, M.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Altarelli, M. Pepe; Perazzini, S.; Perret, P.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. -H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Sena, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Sheychenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; Van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Vazquez Regueiro, P.; Vazquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Barbosa, J. V. V. B. Viana; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; de Vries, J. A.; Wraldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M. P.; Williams, M.; Wilschut, H. W.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyae, M.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.
2015-01-01
Two structures are observed close to the kinematic threshold in the Xi(0)(b)pi(-) mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), recorded by the LEICb experiment. In the quark model, two baryonic resonances with quark content bds a
Radiative decays of negative parity heavy baryons in QCD
Agamaliev, A K; Savcı, M
2016-01-01
The transition form factors responsible for the radiative $\\Sigma_Q \\to \\Lambda_Q \\gamma$ and $\\Xi_Q^\\prime \\to \\Xi \\gamma$ decays of the negative parity baryons are examined within light cone QCD sum rules. The decay widths of the radiative transitions are calculated using the obtained results of the form factors.
Spectrum and Structure of Excited Baryons with CLAS
Burkert, Volker D
2016-01-01
In this contribution we discuss recent results in light quark baryon spectroscopy involving CLAS data and higher level analysis results from the partial wave analysis by the Bonn-Gatchina group. New baryon states were discovered largely based on the open strangeness production channels $\\gamma p \\to K^+ \\Lambda$ and $\\gamma p \\to K^+ \\Sigma^0$. The data illustrate the great potential of the kaon-hyperon channel in the discovery of higher mass baryon resonances in s-channel production. Other channels with discovery potential, such as $\\gamma p \\to p \\omega$ and $\\gamma p \\to \\phi p$ are also discussed. In the second part I will demonstrate on data the sensitivity of meson electroproduction to expose the active degrees of freedom underlying resonance transitions as a function of the probed distance scale. For several of the prominent excited states in the lower mass range the short distance behavior is described by a core of three dressed-quarks with running quark mass, and meson-baryon contributions make up si...
Algebraic models of hadron structure I. Nonstrange baryons
Bijker, R; Leviatan, A
1994-01-01
We introduce an algebraic framework for the description of baryons. Within this framework we study a collective string-like model and show that this model gives a good overall description of the presently available data. We discuss in particular masses and electromagnetic couplings, including the transition form factors that can be measured at new electron facilities.
Algebraic Models of Hadron Structure; 2, Strange Baryons
Bijker, R; Leviatan, A
2000-01-01
The algebraic treatment of baryons is extended to strange resonances. Within this framework we study a collective string-like model in which the radial excitations are interpreted as rotations and vibrations of the strings. We derive a mass formula and closed expressions for strong and electromagnetic decay widths and use these to analyze the available experimental data.
Algebraic models of hadron structure. I. Nonstrange baryons
Energy Technology Data Exchange (ETDEWEB)
Bijker, R. [Univ. of Utrecht (Netherlands); Iachello, F. [Yale Univ., New Haven, CT (United States); Leviatan, A. [Hebrew Univ., Jerusalem (Israel)
1994-11-15
The authors introduce an algebraic framework for the description of baryons. Within this framework they study a collective string-like model and show that this model gives a good overall description of the presently available data. They discuss in particular masses and electromagnetic couplings, including the transition form factors that can be measured at new electron facilities. 44 refs., 15 figs., 11 tabs.
Dense baryonic matter in strong coupling lattice gauge theory
Bringoltz, B
2004-01-01
We investigate the strong coupling limit of lattice QCD in the Hamiltonian formulation for systems with non-zero baryon density. In leading order the Hamiltonian looks like an antiferromagnet that is invariant under global U(N_f)xU(N_f) and local SU(N_c). Physically it describes meson dynamics with a fixed background of baryon density. We study this Hamiltonian with several baryon number distributions, and concentrate on the global symmetries of the ground state and on the properties of low lying excitations. In particular, for uniform non-zero baryon density we write the partition function as a path integral that is tractable in the limit of large N_c. We find that the ground state spontaneously breaks chiral symmetry as well as discrete lattice rotations in a way that depends on N_f and the density. The low energy excitations include type I and type II Goldstone bosons. The energies of the latter are of order 1/N_c, and are quadratic in momentum. Bosons of either type can develop anisotropic dispersion rela...
Constraining Dark Matter-Baryon Scattering with Linear Cosmology
Dvorkin, Cora; Kamionkowski, Marc
2013-01-01
We derive constraints on elastic scattering between baryons and dark matter using the cosmic microwave background (CMB) data from the Planck satellite and the Lyman-alpha forest data from the Sloan Digital Sky Survey. Elastic scattering allows baryons and dark matter to exchange momentum, affecting the dynamics of linear density perturbations in the early Universe. We derive constraints to scattering cross sections of the form sigma \\propto v^n, allowing for a wide range of velocity dependencies with n between -4 and 2. We improve and correct previous estimates where they exist, including velocity-independent cross section as well as dark matter millicharge and electromagnetic dipole moments. Lyman-alpha forest data dominates the constraints for n>-3, where the improvement over CMB data alone can be several orders of magnitude. Dark matter-baryon scattering cannot affect the halo mass function on mass scales M>10^{12} M_{solar}. Our results imply, model-independently, that a baryon in the halo of a galaxy lik...
New Observations of beauty baryon decays at LHCb
Vitaly, Andreev
2014-01-01
This report describes the work I have done during my summer student association with the LHCb (Large Hadron Collider Beauty Experiment) collaboration at CERN from 30.06 till 26.09.2014. The project was performed in a team with two other summer students. In this report I concentrate on my contribution to the team work. In addition, one section is dedicated to the management framework called “scrum” which we used to collaborate as a team. The goal of my task was to analyze yet unobserved decays of the beauty Lambda-b-0 baryon. This is interesting since the CP violation still remains unobserved in baryons and beauty baryons are generally not well-known yet. LHCb is the first detector where these heavy baryons can be analyzed in detail. In addition these decays may play an important role in other processes and one can gain new insights into the strong interaction. The analysis presented here was performed on the full 2011-2012 LHC run data and includes several decays which are observed for the first time.
Factorization of heavy-to-light baryonic transitions in SCET
Energy Technology Data Exchange (ETDEWEB)
Wang, Wei
2011-12-15
In the framework of the soft-collinear effective theory, we demonstrate that the leading-power heavy-to-light baryonic form factors at large recoil obey the heavy quark and large energy symmetries. Symmetry breaking effects have several origins but all of them are suppressed by {lambda}/m{sub b} or {lambda}/E, where {lambda} is the hadronic scale, m{sub b} is the b quark mass and E{proportional_to}m{sub b} is the energy of light baryon in the final state. Including the energy release dependence, we derive the scaling law for form factors {xi}{sub {lambda}}{sub ,p}{proportional_to}{lambda}{sup 2} /E{sup 2}, which is in accordance with the implication from the experimental measurement on the branching ratio of {lambda}{sub b} {yields} p{pi}{sup -}. At leading order in {alpha}{sub s}, the leading-power baryonic form factors can factorize into the soft and collinear matrix elements without encountering any divergence. A leading-power factorization formula for nonleptonic b-baryon decays is also established. (orig.)
The Inner Regions of Disk Galaxies: A Constant Baryonic Fraction?
Directory of Open Access Journals (Sweden)
Federico Lelli
2014-07-01
Full Text Available For disk galaxies (spirals and irregulars, the inner circular-velocity gradient dRV0 (inner steepness of the rotation curve correlates with the central surface brightness ∑*,0 with a slope of ~0.5. This implies that the central dynamical mass density scales almost linearly with the central baryonic density. Here I show that this empirical relation is consistent with a simple model where the central baryonic fraction ƒbar,0 is fixed to 1 (no dark matter and the observed scatter is due to differences in the baryonic mass-to-light ratio Mbar / LR (ranging from 1 to 3 in the R-band and in the characteristic thickness of the central stellar component Δz (ranging from 100 to 500 pc. Models with lower baryonic fractions are possible, although they require some fine-tuning in the values of Mbar/LR and Δz. Regardless of the actual value of ƒbar,0, the fact that different types of galaxies do not show strong variations in ƒbar,0 is surprising, and may represent a challenge for models of galaxy formation in a Λ Cold Dark Matter (ΛCDM cosmology.
Thermodynamics of Hot Hadronic Gases at Finite Baryon Densities
Albright, Michael Glenn
In this thesis we investigate equilibrium and nonequilibrium thermodynamic properties of Quantum Chromodynamics (QCD) matter at finite baryon densities. We begin by constructing crossover models for the thermodynamic equation of state. These use switching functions to smoothly interpolate between a hadronic gas model at low energy densities to a perturbative QCD equation of state at high energy densities. We carefully design the switching function to avoid introducing first-, second-, or higher-order phase transitions which lattice QCD indicates are not present at small baryon chemical potentials. We employ three kinds of hadronic models in the crossover constructions, two of which include repulsive interactions via an excluded volume approximation while one model does not. We find that the three crossover models are in excellent agreement with accurate lattice QCD calculations of the equation of state over a wide range of temperatures and baryon chemical potentials. Hence, the crossover models should be very useful for parameterizing the equation of state at finite baryon densities, which is needed to build next-generation hydrodynamic simulations of heavy-ion collisions. We next calculate the speed of sound and baryon number fluctuations predicted by the crossover models. We find that crossover models with hadronic repulsion are most successful at reproducing the lattice results, while the model without repulsion is less successful, and hadron (only) models show poor agreement. We then compare the crossover models to net-proton fluctuation measurements from the STAR Collaboration at the Relativistic Heavy Ion Collider (RHIC). The comparisons suggest baryon number fluctuations freeze-out well below the chemical freeze-out temperature. We also search for signs of critical fluctuations in the STAR data, but we find no evidence for them at this time. Finally, we derive kinetic theory formulas for the shear and bulk viscosity and thermal conductivity of hot hadronic
The search for exotic baryons at the HERMES experiment
Energy Technology Data Exchange (ETDEWEB)
Deconinck, Wouter
2008-07-15
One of the interesting questions of Quantum Chromodynamics, the theory that governs the interactions between quarks and gluons, has been whether it is possible to observe hadrons which can not be explained as a combination of only two or three valence quarks. In numerous searches the existence of these exotic hadrons could not be confirmed. Recently, calculations based on the quark soliton model predicted the narrow exotic baryons {theta}{sup +} and {xi}{sup --}. A narrow resonance identified as the {theta}{sup +} was observed by several experiments at the predicted mass of 1540 MeV, but later followed by several dedicated experiments that could not confirm these positive results. At the HERMES experiment a search for the quasi-real photoproduction of the exotic baryon {theta}{sup +} on a deuterium target and the subsequent decay through pK{sup 0}{sub S} {yields} p{pi}{sup +}{pi}{sup -} revealed a narrow resonance in the pK{sup 0}{sub S} invariant mass distribution at 1528 MeV. In the search for the corresponding antiparticle {xi}{sup --} the result is consistent with zero events. In this thesis we present the search for the exotic baryon {xi}{sup --} on a deuterium target in the data sample used for the observation of the {theta}{sup +}. An upper limit on the cross section of the exotic baryon {xi}{sup --} is determined. The search for the exotic baryon {theta}{sup +} on hydrogen and deuterium targets at the HERMES experiment is extensively discussed. The event mixing method can be used to estimate the distribution of background events. Several difficulties with this method were addressed, but the background description in the case of the exotic baryon {theta}{sup +} remains unconvincing. Between the years 2002 and 2005 the HERMES experiment operated with a magnetic holding field around the hydrogen target. A method for the reconstruction of displaced vertices in this field was developed. The data collected during the years 2006 and 2007 offer an integrated
Simultaneous Generation of WIMP Miracle-like Densities of Baryons and Dark Matter
McDonald, John
2012-09-01
The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the baryon density is physically related to a typical thermal relic WIMP dark matter density. We present a model which simultaneously generates thermal relic WIMP-like densities for both baryons and dark matter by modifying a large initial baryon asymmetry. Production of unstable scalars carrying baryon number at the LHC would be a clear signature of the model.
Generation of WIMP Miracle-like Densities of Baryons and Dark Matter
McDonald, John
2012-01-01
The observed density of dark matter is of the magnitude expected for a thermal relic weakly-interacting massive particle (WIMP). In addition, the observed baryon density is within an order of magnitude of the dark matter density. This suggests that the baryon density is physically related to a typical thermal relic WIMP dark matter density. We present a model which simultaneously generates thermal relic WIMP-like densities for both baryons and dark matter by modifying a large initial baryon asymmetry. Production of unstable scalars carrying baryon number at the LHC would be a clear signature of the model.
Magnetic Moments of Octet Baryons in Hot and Dense Nuclear Matter
Singh, Harpreet; Dahiya, Harleen
2016-01-01
We have calculated the in-medium magnetic moments of octet baryons in the presence of hot and dense symmetric nuclear matter. Effective magnetic moments of baryons have been derived from medium modified quark masses within chiral SU(3) quark mean field model.Further, for better insight of medium modification of baryonic magnetic moments, we have considered the explicit contributions from the valence as well as sea quark effects. These effects have been successful in giving the description of baryonic magnetic moments in vacuum. The magnetic moments of baryons are found to vary significantly as a function of density of nuclear medium.
Intriguing aspects in baryon production at relativistic heavy-ion collider
Indian Academy of Sciences (India)
Huan Zhong Huang
2003-05-01
We review experimental results on baryon production at mid-rapidity in nucleus–nucleus collisions at RHIC. Outstanding physics issues include the mechanism for baryon–anti-baryon production from thermally equilibrated partons, the dynamics of baryon number transport and the evolution dynamics of baryons during hadronic expansion before the ﬁnal freeze-out. We highlight recent measurements on the production of protons, lambdas and their anti-particles in terms of these physics issues. We propose a physical mechanism of topological baryon formation through gluon junction hadronization and future measurements, which can test this hypothesis experimentally.
Haidenbauer, J.; Meißner, Ulf-G.; Petschauer, S.
2016-10-01
The strangeness S = - 2 baryon-baryon interaction is studied in chiral effective field theory up to next-to-leading order. The potential at this order consists of contributions from one- and two-pseudoscalar-meson exchange diagrams and from four-baryon contact terms without and with two derivatives. SU(3) flavor symmetry is imposed for constructing the interaction in the S = - 2 sector. Specifically, the couplings of the pseudoscalar mesons to the baryons are fixed by SU(3) symmetry and, in general, also the contact terms are related via SU(3) symmetry to those determined in a previous study of the S = - 1 hyperon-nucleon interaction. The explicit SU(3) symmetry breaking due to the physical masses of the pseudoscalar mesons (π, K, η) is taken into account. It is argued that the ΞN interaction has to be relatively weak to be in accordance with available experimental constraints. In particular, the published values and upper bounds for the Ξ- p elastic and inelastic cross sections apparently rule out a somewhat stronger attractive ΞN force and, specifically, disfavor any near-threshold deuteron-like bound states in that system.
Appelquist, Thomas; Brower, Richard C; Buchoff, Michael I; Fleming, George T; Kiskis, Joe; Kribs, Graham D; Lin, Meifeng; Neil, Ethan T; Osborn, James C; Rebbi, Claudio; Rinaldi, Enrico; Schaich, David; Schroeder, Chris; Syritsyn, Sergey; Voronov, Gennady; Vranas, Pavlos; Weinberg, Evan; Witzel, Oliver
2014-01-01
We present the spectrum of baryons in a new SU(4) gauge theory with fundamental fermion constituents. The spectrum of these bosonic baryons is of significant interest for composite dark matter theories. Here, we compare the spectrum and properties of SU(3) and SU(4) baryons, and then compute the dark-matter direct detection cross section via Higgs boson exchange for TeV-scale composite dark matter arising from a confining SU(4) gauge sector. Comparison with the latest LUX results leads to tight bounds on the fraction of the constituent-fermion mass that may arise from electroweak symmetry breaking. Lattice calculations of the dark matter mass spectrum and the Higgs-dark matter coupling are performed on quenched $16^{3} \\times 32$, $32^{3} \\times 64$, $48^{3} \\times 96$, and $64^{3} \\times128$ lattices with three different lattice spacings, using Wilson fermions with moderate to heavy pseudoscalar meson masses. Our results lay a foundation for future analytic and numerical study of composite baryonic dark matt...
Multiplicity fluctuation and correlation of identified baryons in quark combination model
Song, Jun; Wang, Rui-qin; Shao, Feng-lan
2016-01-01
The dynamical fluctuation and correlation of multiplicity distributions of identified baryons and antibaryons produced by the hadronization of the bulk quark system are systematically studied in quark combination model. Starting from the most basic dynamics of quark combination which are necessary for multiplicity study, we analyze moments (variance, skewness and kurtosis) of inclusive multiplicity distribution of identified baryons, two-baryon multiplicity correlations, and baryon-antibaryon multiplicity correlations after the hadronization of quark system with given quark number and antiquark number. We obtain a series of interesting findings, e.g., binomial behavior of multiplicity moments, coincide flavor dependent two-baryon correlation and universal baryon-antibaryon correlation, which can be regarded as general features of quark combination. We further take into account correlations and fluctuations of quark numbers before hadronization to study their influence on multiple production of baryons and ant...
Phenomenology of neutrino oscillations
Indian Academy of Sciences (India)
G Rajasekaran
2000-07-01
The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.
Ma, Hongbin
2015-01-01
This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation, theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary factors affecting oscillating motions and heat transfer, neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes. The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...
The impact of the supersonic baryon-dark matter velocity difference on the z~20 21cm background
McQuinn, Matthew
2012-01-01
Recently, Tseliakhovich and Hirata (2010) showed that during the cosmic Dark Ages the baryons were typically moving supersonically with respect to the dark matter with a spatially variable Mach number. Such supersonic motion may source shocks that heat the Universe. This motion may also suppress star formation in the first halos. Even a small amount of coupling of the 21cm signal to this motion has the potential to vastly enhance the 21cm brightness temperature fluctuations at 15
The colpitts oscillator family
DEFF Research Database (Denmark)
Lindberg, Erik; Murali, K.; Tamasevicius, A.
A tutorial study of the Colpitts oscillator family defined as all oscillators based on a nonlinear amplifier and a three- terminal linear resonance circuit with one coil and two capacitors. The original patents are investigated. The eigenvalues of the linearized Jacobian for oscillators based...
Neutrino Masses and Oscillations
Valle, J W F
2005-01-01
I summarize the status of three--neutrino oscillations that follow from combining the relevant world's data. The discussion includes the small parameters Delta_m-sol/Delta_m-atm and \\sin^2\\theta_{13}, which characterize the strength of CP violation in neutrino oscillations, the impact of oscillation data on the prospects for probing the absolute scale of neutrino mass in \
a Study of the Decay Properties of the Charmed Baryon Charmed Positive Lambda Baryon
Charlesworth, Catriona Elizabeth Kaye
The charmed baryon Lambda_sp {c}{+} has been observed using the ARGUS detector in the DORIS II e^{+ }e^- storage ring at DESY. The ARGUS experiment is a 4pi magnetic solenoidal detector used to observe e^{+}e ^- annihilations at center-of-mass energies around 10.4 GeV. We have studied 5 decays modes of the Lambda_sp{c}{+}. The decay mode Lambda_sp{c} {+}to pK^-pi^+ was used to measure the Lambda_sp {c}{+} fragmentation properties. A value of 0.24 +/- 0.04 was found for the Peterson et al. parameter epsilon, and the sigma(Lambda_sp{c }{+}) cdot BR( Lambda_sp{c}{+}to pK^-pi^+) was measured to be 12.0 +/- 1.1 +/- 1.3) pb. The decay modes Lambda_sp {c}{+}toLambdapi^+ and Lambda_sp{c} {+}toSigma^0pi^+ were also studied. In the former the asymmetry parameter alpha_{Lambda _{c}} was measured to be -1.0 +/- 0.5, indicating that parity is maximally violated in this decay. The two production cross section times branching ratios were measured to be (2.2 +/- 0.3 +/- 0.3) pb and (2.0 +/- 0.7 +/- 0.3) pb respectively. Finally, a search was made for evidence of W-exchange in the decay Lambda_sp{c}{+} toXi^-K^+pi^+. This final state can arise through a simple spectator decay or via the more exotic W-exchange decay into Xi ^{*0}K^+, where the Xi^{*0} subsequently decays into Xi^-pi^+. The two body rate was measured to be (35 +/- 17)% of the three body rate, indicating that a significant portion of the Xi^-K^+pi ^+ final state may occur via W-exchange.
Molecular Structures in Hidden Charm Meson and Charmed Baryon Spectrum
Fernandez, F; Ortega, P G
2013-01-01
Using a constituent quark model we study the mass and decay channels of meson meson and meson baryon structures in the charm sector. We show that the $X(3872)$ and $X(3940)$ resonances can be described as mixed charmonium-molecular states with $J^{PC}=1^{++}$, whereas the $X(3915)$ and the $Y(3940)$ can be assigned to similar mixed states with $J^{PC}=0^{++}$. In the baryon spectrum we identify the $\\Lambda^+_c(2940)$ as a $D^*N$ molecule with $(I)J^P=(0)3/2^-$ and the recently reported $X_c(3250)$ as a $D^*\\Delta$ resonance with $(I)J^P=(1)5/2^-$ or $(I)J^P=(2)3/2^-$.
Baryon Spectroscopy Through Partial-Wave Analysis and Meson Photoproduction
Energy Technology Data Exchange (ETDEWEB)
Manley, D. Mark [Kent State Univ., Kent, OH (United States)
2016-09-08
The principal goal of this project is the experimental and phenomenological study of baryon spectroscopy. The PI's group consists of himself and three graduate students. This final report summarizes research activities by the PI's group during the period 03/01/2015 to 08/14/2016. During this period, the PI co-authored 11 published journal papers and one proceedings article and presented three invited talks. The PI's general interest is the investigation of the baryon resonance spectrum up to masses of ~ 2 GeV. More detail is given on two research projects: Neutral Kaon Photoproduction and Partial-Wave Analyses of γp → η p, γn → η n, and γp → K⁺ Λ.