# V. V. Kulikov - ITEP

## Contact Details

NameV. V. Kulikov |
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AffiliationITEP |
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Location |
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## Pubs By Year |
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## External Links |
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## Pub CategoriesHigh Energy Physics - Experiment (20) Mathematics - Algebraic Geometry (11) Nuclear Experiment (10) Mathematics - Logic (9) Nuclear Theory (4) Mathematics - Group Theory (3) Physics - Atmospheric and Oceanic Physics (2) Mathematics - General Topology (2) High Energy Physics - Phenomenology (2) Mathematics - Geometric Topology (2) Statistics - Theory (1) Mathematics - Statistics (1) Mathematics - Classical Analysis and ODEs (1) Physics - Instrumentation and Detectors (1) Quantum Physics (1) |

## Publications Authored By V. V. Kulikov

We prove that for a generic Lefschetz pencil of plane curves of degree $d\geq 3$ there exists a curve $H$ (called the Hesse curve of the pencil) of degree $6(d-1)$ and genus $3(4d^2-13d+8)+1$, and such that: $(i)$ $H$ has $d^2$ singular points of multiplicity three at the base points of the pencil and $3(d-1)^2$ ordinary nodes at the singular points of the degenerate members of the pencil; $(ii)$ for each member of the pencil the intersection of $H$ with this fibre consists of the inflection points of this member and the base points of the pencil. Read More

We prove that the monodromy group of the inflection points of plane curves of degree $d$ is the symmetric group $\mathbb S_{3d(d-2)}$ for $d\geq 4$ and in the case $d=3$ this group is the group of the projective transformations of $\mathbb P^2$ leaving invariant the nine inflection points of the Fermat curve of degree three. Read More

**Authors:**P. Adlarson, F. Afzal, P. Aguar-Bartolomé, Z. Ahmed, C. S. Akondi, J. R. M. Annand, H. J. Arends, K. Bantawa, R. Beck, H. Berghäuser, M. Biroth, N. S. Borisov, A. Braghieri, W. J. Briscoe, S. Cherepnya, F. Cividini, C. Collicott, S. Costanza, A. Denig, M. Dieterle, E. J. Downie, P. Drexler, M. I. Ferretti Bondy, L. V. Fil'kov, S. Gardner, S. Garni, D. I. Glazier, D. Glowa, W. Gradl, G. M. Gurevich, D. J. Hamilton, D. Hornidge, G. M. Huber, T. C. Jude, A. Käser, V. L. Kashevarov, S. Kay, I. Keshelashvili, R. Kondratiev, M. Korolija, B. Krusche, V. V. Kulikov, A. Lazarev, J. Linturi, V. Lisin, K. Livingston, I. J. D. MacGregor, R. Macrae, D. M. Manley, P. P. Martel, M. Martemianov, J. C. McGeorge, E. F. McNicoll, V. Metag, D. G. Middleton, R. Miskimen, E. Mornacchi, C. Mullen, A. Mushkarenkov, A. Neganov, A. Neiser, A. Nikolaev, M. Oberle, M. Ostrick, P. Ott, P. B. Otte, D. Paudyal, P. Pedroni, A. Polonski, S. Prakhov, A. Rajabi, J. Robinson, G. Ron, G. Rosner, T. Rostomyan, C. Sfienti, M. H. Sikora, V. Sokhoyan, K. Spieker, O. Steffen, I. I. Strakovsky, B. Strandberg, Th. Strub, I. Supek, A. Thiel, M. Thiel, A. Thomas, M. Unverzagt, Yu. A. Usov, S. Wagner, N. Walford, D. P. Watts, D. Werthmüller, J. Wettig, L. Witthauer, M. Wolfes, L. A. Zana

The Dalitz decay pi^0 -> e^+e^-gamma has been measured in the gamma p -> pi^0 p reaction with the A2 tagged-photon facility at the Mainz Microtron, MAMI. The value obtained for the slope parameter of the pi^0 electromagnetic transition form factor, a_pi = 0.030+/-0. Read More

**Authors:**V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, A. M. Batrakov, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, D. N. Grigoriev, Yu. M. Glukhovchenko, S. E. Karnaev, G. V. Karpov, S. V. Karpov, P. V. Kasyanenko, T. A. Kharlamova, V. A. Kiselev, V. V. Kolmogorov, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. N. Kudryavtsev, V. F. Kulikov, G. Ya. Kurkin, I. A. Kuyanov, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, A. A. Osipov, I. V. Ovtin, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, V. G. Prisekin, O. L. Rezanova, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have determined the values of $R$ at thirteen points of the center-of-mass energy between 1.84 and 3.05 GeV. Read More

We study the Borel-reducibility of isomorphism relations of complete first order theories and show the consistency of the following: For all such theories T and T', if T is classifiable and T' is not, then the isomorphism of models of T' is strictly above the isomorphism of models of T with respect to Borel-reducibility. In fact, we can also ensure that a range of equivalence relations modulo various non-stationary ideals are strictly between those isomorphism relations. The isomorphism relations are considered on models of some fixed uncountable cardinality obeying certain restrictions. Read More

**Authors:**Igor Strakovsky

^{1}, William Briscoe

^{2}, Alexander Kudryavtsev

^{3}, Viacheslav Kulikov

^{4}, Maxim Martemianov

^{5}, Vladimir Tarasov

^{6}, Ron Workman

^{7}

**Affiliations:**

^{1}GW,

^{2}GW,

^{3}ITEP/GW,

^{4}ITEP,

^{5}ITEP,

^{6}ITEP,

^{7}ITEP

An overview of the GW SAID and ITEP groups' effort to analyze pion photoproduction on the neutron-target will be given. The disentanglement of the isoscalar and isovector EM couplings of N* and Delta* resonances does require compatible data on both proton and neutron targets. The final-state interaction plays a critical role in the state-of-the-art analysis in extraction of the gn-->piN data from the deuteron target experiments. Read More

**Authors:**V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, A. M. Batrakov, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, D. N. Grigoriev, Yu. M. Glukhovchenko, S. E. Karnaev, G. V. Karpov, S. V. Karpov, P. V. Kasyanenko, T. A. Kharlamova, V. A. Kiselev, V. V. Kolmogorov, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. N. Kudryavtsev, V. F. Kulikov, G. Ya. Kurkin, I. A. Kuyanov, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, A. A. Osipov, I. V. Ovtin, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, V. G. Prisekin, O. L. Rezanova, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have measured the values of $R_{\text{uds}}$ and $R$ at seven points of the center-of-mass energy between 3.12 and 3.72 GeV. Read More

Nuclear fragments emitted at 3.5 degrees in 12C fragmentation at 0.6 GeV/nucleon have been measured. Read More

**Authors:**P. Adlarson, F. Afzal, C. S. Akondi, J. R. M. Annand, H. J. Arends, Ya. I. Azimov, R. Beck, N. Borisov, A. Braghieri, W. J. Briscoe, S. Cherepnya, F. Cividini, C. Collicott, S. Costanza, A. Denig, E. J. Downie, M. Dieterle, M. I. Ferretti Bondy, L. V. Fil'kov, A. Fix, S. Gardner, S. Garni, D. I. Glazier, D. Glowa, W. Gradl, G. Gurevich, D. J. Hamilton, D. Hornidge, G. M. Huber, A. Käser, V. L. Kashevarov, S. Kay, I. Keshelashvili, R. Kondratiev, M. Korolija, B. Krusche, V. V. Kulikov, A. Lazarev, J. Linturi, V. Lisin, K. Livingston, I. J. D. MacGregor, D. M. Manley, P. P. Martel, M. Martemianov, J. C. McGeorge, W. Meyer, D. G. Middleton, R. Miskimen, A. Mushkarenkov, A. Neganov, A. Neiser, M. Oberle, M. Ostrick, P. Ott, P. B. Otte, B. Oussena, D. Paudyal, P. Pedroni, A. Polonski, V. V. Polyanski, S. Prakhov, A. Rajabi, G. Reicherz, G. Ron, T. Rostomyan, A. Sarty, D. M. Schott, S. Schumann, C. Sfienti, V. Sokhoyan, K. Spieker, O. Steffen, I. I. Strakovsky, Th. Strub, I. Supek, M. F. Taragin, A. Thiel, M. Thiel, L. Tiator, A. Thomas, M. Unverzagt, Yu. A. Usov, S. Wagner, D. P. Watts, D. Werthmüller, J. Wettig, L. Witthauer, M. Wolfes, R. L. Workman, L. A. Zana

Differential cross sections for the gamma p -> pi^0 p reaction have been measured with the A2 tagged-photon facilities at the Mainz Microtron, MAMI C, up to the center-of-mass energy W=1.9 GeV. The new results, obtained with a fine energy and angular binning, increase the existing quantity of pi^0 photoproduction data by ~47%. Read More

Using methods of descriptive theory it is shown that the classification problem for wild knots is strictly harder than that for countable structures. Read More

**Authors:**M. Martemianov, V. Kulikov, B. T. Demissie, Z. Marinides, C. S. Akondi, J. R. M. Annand, H. J. Arends, R. Beck, N. Borisov, A. Braghieri, W. J. Briscoe, S. Cherepnya, C. Collicott, S. Costanza, E. J. Downie, M. Dieterle, M. I. Ferretti Bondy, L. V. Filkov, S. Garni, D. I. Glazier, D. Glowa, W. Gradl, G. Gurevich, D. Hornidge, G. M. Huber, A. Kaeser, V. L. Kashevarov, I. Keshelashvili, R. Kondratiev, M. Korolija, B. Krusche, A. Lazarev, J. M. Linturi, V. Lisin, K. Livingston, I. J. D. MacGregor, D. M. Manley, P. P. Martel, D. G. Middleton, R. Miskimen, A. Mushkarenkov, A. Neganov, A. Neiser, M. Oberle, M. Ostrick, P. Ott, P. B. Otte, B. Oussena, P. Pedroni, A. Polonski, S. Prakhov, G. Ron, T. Rostomyan, A. Sarty, D. M. Schott, S. Schumann, V. Sokhoyan, O. Steffen, I. I. Strakovsky, Th. Strub, I. Supek, M. Thiel, A. Thomas, M. Unverzagt, Yu. A. Usov, S. Wagner, D. P. Watts, J. Wettig, D. Werthmuller, L. Witthauer, M. Wolfes

We report on a measurement of the neutron detection efficiency in NaI crystals in the Crystal Ball detector obtained from a study of single p0 photoproduction on deuterium using the tagged photon beam at the Mainz Microtron. The results were obtained up to a neutron energy of 400 MeV. They are compared to previous measurements made more than 15 years ago at the pion beam at the BNL AGS. Read More

Momentum spectra of hydrogen isotopes have been measured at 3.5 deg from C12 fragmentation on a Be target. Momentum spectra cover both the region of fragmentation maximum and the cumulative region. Read More

In the article, we exhibit a series of new examples of rigid plane curves, that is, curves, whose collection of singularities determines them almost uniquely up to a projective transformation of the plane. Read More

**Authors:**Igor I. Strakovsky

^{1}, William J. Briscoe

^{2}, Alexander E. Kudryavtsev

^{3}, Viacheslav V. Kulikov

^{4}, Maxim A. Martemyanov

^{5}, Vladimir E. Tarasov

^{6}

**Affiliations:**

^{1}GW,

^{2}GW,

^{3}ITEP, GW,

^{4}ITEP,

^{5}ITEP,

^{6}ITEP

An overview of the GW SAID and ITEP groups effort to analyze pion photoproduction on the neutron-target will be given. The disentanglement the isoscalar and isovector EM couplings of N* and Delta* resonances does require compatible data on both proton and neutron targets. The final-state interaction plays a critical role in the state-of-the-art analysis in extraction of the gamma n --> pi N data from the deuteron target experiments. Read More

We study the geometry of equiclassical strata of the discriminant in the space of plane curves of a given degree, which are families of curves of given degree, genus and class (degree of the dual curve). Our main observation is that the use of duality transformation leads to a series of new sufficient conditions for a regular behavior of the equiclassical stratification. We also discuss duality of curves in higher-dimensional projective spaces and in Grassmannians with focus on similar questions of the regularity of equiclassical families of spacial curves. Read More

We investigate regularity properties derived from tree-like forcing notions in the setting of "generalized descriptive set theory", i.e., descriptive set theory on $\kappa^\kappa$ and $2^\kappa$, for regular uncountable cardinals $\kappa$. Read More

We prove results that falsify Silver's dichotomy for Borel equivalence relations on the generalised Baire space under the assumption V=L. Read More

In this paper we study the Borel reducibility of Borel equivalence relations, including some orbit equivalence relations, on the generalised Baire space $\kappa^\kappa$ for an uncountable $\kappa$ with the property $\kappa^{<\kappa}=\kappa$. The theory looks quite different from its classical counterpart where $\kappa=\omega$, although some basic theorems do generalise. Read More

The paper deals with the program of determining the complexity of various homeomorphism relations. The homeomorphism relation on compact Polish spaces is known to be reducible to an orbit equivalence relation of a continuous Polish group action (Kechris-Solecki). It is shown that this result extends to locally compact Polish spaces, but does not hold for spaces in which local compactness fails at only one point. Read More

**Authors:**J-PARC E19 Collaboration, :, M. Moritsu, S. Adachi, M. Agnello, S. Ajimura, K. Aoki, H. C. Bhang, B. Bassalleck, E. Botta, S. Bufalino, N. Chiga, H. Ekawa, P. Evtoukhovitch, A. Feliciello, H. Fujioka, S. Hayakawa, F. Hiruma, R. Honda, K. Hosomi, Y. Ichikawa, M. Ieiri, Y. Igarashi, K. Imai, N. Ishibashi, S. Ishimoto, K. Itahashi, R. Iwasaki, C. W. Joo, S. Kanatsuki, M. J. Kim, S. J. Kim, R. Kiuchi, T. Koike, Y. Komatsu, V. V. Kulikov, S. Marcello, S. Masumoto, Y. Matsumoto, K. Matsuoka, K. Miwa, T. Nagae, M. Naruki, M. Niiyama, H. Noumi, Y. Nozawa, R. Ota, K. Ozawa, N. Saito, A. Sakaguchi, H. Sako, V. Samoilov, M. Sato, S. Sato, Y. Sato, S. Sawada, M. Sekimoto, K. Shirotori, H. Sugimura, S. Suzuki, H. Takahashi, T. Takahashi, T. N. Takahashi, H. Tamura, T. Tanaka, K. Tanida, A. O. Tokiyasu, N. Tomida, Z. Tsamalaidze, M. Ukai, K. Yagi, T. O. Yamamoto, S. B. Yang, Y. Yonemoto, C. J. Yoon, K. Yoshida

The pentaquark $\Theta^+$ has been searched for via the $\pi^-p \to K^-X$ reaction with beam momenta of 1.92 and 2.01 GeV/$c$ at J-PARC. Read More

**Authors:**V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, I. V. Bedny, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, Yu. M. Glukhovchenko, V. V. Gulevich, D. V. Gusev, S. E. Karnaev, G. V. Karpov, S. V. Karpov, T. A. Kharlamova, V. A. Kiselev, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. F. Kulikov, G. Ya. Kurkin, E. A. Kuper, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, A. S. Medvedko, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, I. O. Orlov, A. A. Osipov, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, A. O. Poluektov, G. E. Pospelov, V. G. Prisekin, O. L. Rezanova, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, V. V. Smaluk, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, A. N. Yushkov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

Using the inclusive photon spectrum based on a data sample collected at the $J/\psi$ peak with the KEDR detector at the VEPP-4M $e^+e^-$ collider, we measured the rate of the radiative decay $J/\psi\to\gamma\eta_{\rm c}$ as well as $\eta_{\rm c}$ mass and width. Taking into account an asymmetric photon lineshape we obtained $\Gamma^0_{\gamma\eta_{\rm c}}=2.98\pm0. Read More

In \cite{Ku0}, the ambiguity index $a_{(G,O)}$ was introduced for each equipped finite group $(G,O)$. It is equal to the number of connected components of a Hurwitz space parametrizing coverings of a projective line with Galois group $G$ assuming that all local monodromies belong to conjugacy classes $O$ in $G$ and the number of branch points is greater than some constant. We prove in this article that the ambiguity index can be identified with the size of a generalization of so called Bogomolov multiplier (\cite{Kun1}, see also \cite{BO87}) and hence can be easily computed for many pairs $(G,O)$. Read More

Let $C_1$ be an irreducible component of a reduced projective curve $C\subset \mathbb P^2$ defined over the field $\mathbb C$, $\mathrm{deg} C_1\geq 2$, and let $T$ be the set of lines $l\subset \mathbb P^2$ meeting $C$ transversally. In the article, we prove that for a line $l_0\in T$ and any two points $P_1,P_2\in C_1\cap l_0$ there is a loop $l_t\subset T$, $t\in [0,1]$, such that the movement of the line $l_0$ along the loop $l_t$ induces the transposition of the points $P_1$, $P_2$ and the identity permutation of the other points of $C\cap l_0$. Read More

**Authors:**KEDR Collaboration, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, A. M. Batrakov, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, D. N. Grigoriev, V. R. Groshev, Yu. M. Glukhovchenko, V. V. Gulevich, D. V. Gusev, S. E. Karnaev, G. V. Karpov, S. V. Karpov, T. A. Kharlamova, V. A. Kiselev, V. V. Kolmogorov, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. N. Kudryavtsev, V. F. Kulikov, G. Ya. Kurkin, E. A. Kuper, I. A. Kuyanov, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, I. O. Orlov, A. A. Osipov, I. V. Ovtin, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, A. O. Poluektov, V. G. Prisekin, O. L. Rezanova, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

We report results of experiments performed with the KEDR detector at the VEPP-4M $e^+e^-$ collider. They include final results for the mass and other parameters of the $J/\psi$, $\psi(2S)$ and $\psi(3770)$ and $J/\psi\to\gamma\eta_c$ branching fraction determination. Read More

**Authors:**KEDR Collaboration, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, A. M. Batrakov, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, D. N. Grigoriev, V. R. Groshev, Yu. M. Glukhovchenko, V. V. Gulevich, D. V. Gusev, S. E. Karnaev, G. V. Karpov, S. V. Karpov, T. A. Kharlamova, V. A. Kiselev, V. V. Kolmogorov, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. N. Kudryavtsev, V. F. Kulikov, G. Ya. Kurkin, E. A. Kuper, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, I. O. Orlov, A. A. Osipov, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, A. O. Poluektov, V. G. Prisekin, O. L. Rezanova, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, A. N. Yushkov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

The ratio of the electron and muon widths of the $J/\psi$ meson has been measured using direct $J/\psi$ decays in the KEDR experiment at the VEPP-4M electron-positron collider. The result $\Gamma_{ee}(J/\psi)/\Gamma_{\mu\mu}(J/\psi)=1.0022\pm0. Read More

A thread-shaped intensity field has been observed at 2 m distance when a laser beam passed through a water convection cell with characteristic Rayleigh number about 10^{8}. Similar intensity fields were simulated by using phase screen method for various turbulent spectrum in the cell. We show that experimental result can be described by Tatarskii spectrum which take into account the inner scale. Read More

In this article, we investigate some properties of cyclic coverings of complex surfaces of general type branched along smooth curves that are numerically equivalent to a multiple of the canonical class. The main results concern coverings of surfaces of general type with p_g=0 and Miyaoka--Yau surfaces; in particular, they provide new examples of multicomponent moduli spaces of surfaces with given Chern numbers as well as new examples of surfaces that are not deformation equivalent to their complex conjugates. Read More

In the FRAGM experiment at heavy ion accelerator complex TWAC-ITEP, the proton yields at an angle 3.5$^\circ$ have been measured at fragmentation of carbon ions at $T_0 = $ 0.6, 0. Read More

The space $F(\ell_2)$ of all closed subsets of $\ell_2$ is a Polish space. We show that the subset $P\subset F(\ell_2)$ consisting of the purely 1-unrectifiable sets is $\Pii$-complete. Read More

Working with uncountable structures of fixed cardinality, we investigate the complexity of certain equivalence relations and show that if V = L, then many of them are \Sigma^1_1-complete, in particular the isomorphism relation of dense linear orders. Then we show that it is undecidable in ZFC whether or not the isomorphism relation of a certain well behaved theory (stable, NDOP, NOTOP) is \Sigma^1_1-complete (it is, if V = L, but can be forced not to be). Read More

We start by giving a survey to the theory of Borel*(\kappa) sets in the generalized Baire space Baire({\kappa}) = {\kappa}^{\kappa}. In particular we look at the relation of this complexity class to other complexity classes which we denote by Borel({\kappa}), \Delta^1_1({\kappa}) and {\Sigma}^1_1({\kappa}) and the connections between Borel*(\kappa)-sets and the infinitely deep language M_{{\kappa}^+{\kappa}}. In the end of the paper we prove the consistency of Borel*(\kappa) \ne {\Sigma}^1_1({\kappa}). Read More

Descriptive set theory is mainly concerned with studying subsets of the space of all countable binary sequences. In this paper we study the generalization where countable is replaced by uncountable. We explore properties of generalized Baire and Cantor spaces, equivalence relations and their Borel reducibility. Read More

It is shown that the power set of $\k$ ordered by the subset relation modulo various versions of the non-stationary deal can be embedded into the partial order of Borel equivalence relations on $2^\k$ under Borel reducibility. Here $\k$ is uncountable regular cardinal with $\k^{<\k}=\k$. Read More

We introduce and study a semigroup structure on the set of irreducible components of the Hurwitz space of marked coverings of a complex projective curve with given Galois group of the coverings and fixed ramification type. As application, we give new conditions on the ramification type that are sufficient for irreducibility of the Hurwitz spaces, suggest some bounds on the number of irreducibility components under certain more general conditions, and show that the number of irreducible components coincides with the number of topological classes of the coverings if the number of brunch points is big enough. Read More

**Authors:**K. Shirotori, T. N. Takahashi, S. Adachi, M. Agnello, S. Ajimura, K. Aoki, H. C. Bang, B. Bassalleck, E. Botta, S. Bufalino, N. Chiga, P. Evtoukhovitch, A. Feliciello, H. Fujioka, F. Hiruma, R. Honda, K. Hosomi, Y. Ichikawa, M. Ieiri, Y. Igarashi, K. Imai, N. Ishibashi, S. Ishimoto, K. Itahashi, R. Iwasaki, C. W. Joo, M. J. Kim, S. J. Kim, R. Kiuchi, T. Koike, Y. Komatsu, V. V. Kulikov, S. Marcello, S. Masumoto, K. Matsuoka, K. Miwa, M. Moritsu, T. Nagae, M. Naruki, M. Niiyama, H. Noumi, K. Ozawa, N. Saito, A. Sakaguchi, H. Sako, V. Samoilov, M. Sato, S. Sato, Y. Sato, S. Sawada, M. Sekimoto, H. Sugimura, S. Suzuki, H. Takahashi, T. Takahashi, H. Tamura, T. Tanaka, K. Tanida, A. O. Tokiyasu, N. Tomida, Z. Tsamalaidze, M. Ukai, K. Yagi, T. O. Yamamoto, S. B. Yang, Y. Yonemoto, C. J. Yoon, K. Yoshida

**Category:**Nuclear Experiment

The $\Theta^+$ pentaquark baryon was searched for via the $\pi^-p\to K^-X$ reaction in a missing-mass resolution of 1.4 MeV/$c^2$(FWHM) at J-PARC. $\pi^-$ meson beams were incident on the liquid hydrogen target with the beam momentum of 1. Read More

Background: Phase-equivalent transformations (PETs) are well-known in quantum scattering and inverse scattering theory. PETs do not affect scattering phase shifts and bound state energies of two-body system but are conventionally supposed to modify two-body bound state observables such as the rms radius and electromagnetic moments. Purpose: In order to preserve all bound state observables, we propose a new particular case of PETs, a deuteron-equivalent transformation (DET-PET), which leaves unchanged not only scattering phase shifts and bound state (deuteron) binding energy but also the bound state wave function. Read More

**Affiliations:**

^{1}A.M.Obukhov Institute of Atmospheric Physics Russian Academy of Sciences, Moscow, Russia,

^{2}Chair of General Physics and Wave Processes Department of Physics, M.V.Lomonosov Moscow State University, Moscow, Russia,

^{3}International Laser Center, M.V.Lomonosov Moscow State University, Moscow, Russia,

^{4}Chair of General Physics and Wave Processes Department of Physics, M.V.Lomonosov Moscow State University, Moscow, Russia

Here we propose an optical method that use phase data of a laser beam obtained from Shack-Hartmann sensor to estimate both inner and outer scales of turbulence. The method is based on the sequential analysis of normalized correlation functions of Zernike coefficients. It allows excluding the value of refractive index structural constant from the analysis and reduces the solution of a two-parameter problem to sequential solution of two single-parameter problems. Read More

Let $f$ be a nonincreasing function defined on $[0,1]$. Under standard regularity conditions, we derive the asymptotic distribution of the supremum norm of the difference between $f$ and its Grenander-type estimator on sub-intervals of $[0,1]$. The rate of convergence is found to be of order $(n/\log n)^{-1/3}$ and the limiting distribution to be Gumbel. Read More

**Authors:**V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, O. L. Beloborodova, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, D. N. Grigoriev, Yu. M. Glukhovchenko, V. V. Gulevich, D. V. Gusev, S. E. Karnaev, G. V. Karpov, S. V. Karpov, T. A. Kharlamova, V. A. Kiselev, V. V. Kolmogorov, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. N. Kudryavtsev, V. F. Kulikov, G. Ya. Kurkin, E. A. Kuper, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, A. S. Medvedko, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, I. O. Orlov, A. A. Osipov, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, A. O. Poluektov, V. G. Prisekin, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, V. V. Smaluk, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, A. N. Yushkov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

We report a new precise determination of the leptonic widths of the J/psi meson performed with the KEDR detector at the VEPP-4M $e^{+}e^{-}$ collider. The measured values of the J/psi parameters are: \Gamma_{ee}\times\Gamma_{ee}/\Gamma = 0.3323 \pm 0. Read More

**Authors:**V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, O. L. Beloborodova, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, D. N. Grigoriev, Yu. M. Glukhovchenko, V. V. Gulevich, D. V. Gusev, S. E. Karnaev, G. V. Karpov, S. V. Karpov, T. A. Kharlamova, V. A. Kiselev, V. V. Kolmogorov, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. N. Kudryavtsev, V. F. Kulikov, G. Ya. Kurkin, E. A. Kuper, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, A. S. Medvedko, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, I. O. Orlov, A. A. Osipov, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, A. O. Poluektov, V. G. Prisekin, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, V. V. Smaluk, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, A. N. Yushkov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

We report the final results of a study of the \psi(3770) meson using a data sample collected with the KEDR detector at the VEPP-4M electron-positron collider. The data analysis takes into account the interference between the resonant and nonresonant $D\bar{D}$ production, where the latter is related to the nonresonant part of the energy-dependent form factor $F_D$. The vector dominance approach and several empirical parameterizations have been tried for the nonresonant $F_D^{\NR}(s)$. Read More

**Authors:**V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, O. L. Beloborodova, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, D. N. Grigoriev, Yu. M. Glukhovchenko, V. V. Gulevich, D. V. Gusev, S. E. Karnaev, G. V. Karpov, S. V. Karpov, T. A. Kharlamova, V. A. Kiselev, V. V. Kolmogorov, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. N. Kudryavtsev, V. F. Kulikov, G. Ya. Kurkin, E. A. Kuper, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, A. S. Medvedko, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, I. O. Orlov, A. A. Osipov, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, A. O. Poluektov, V. G. Prisekin, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, V. V. Smaluk, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, A. N. Yushkov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

A high-precision determination of the main parameters of the \psi(2S) resonance has been performed with the KEDR detector at the VEPP-4M e^{+}e^{-} collider in three scans of the \psi(2S) -- \psi(3770) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the \psi(2S) we obtained the mass value M = 3686.114 +- 0. Read More

**Authors:**The KLOE Collaboration, F. Ambrosino, A. Antonelli, M. Antonelli, F. Archilli, I. Balwierz, G. Bencivenni, C. Bini, C. Bloise, S. Bocchetta, F. Bossi, P. Branchini, G. Capon, T. Capussela, F. Ceradini, P. Ciambrone, E. Czerwiski, E. De Lucia, A. De Santis, P. De Simone, G. De Zorzi, A. Denig, A. Di Domenico, C. Di Donato, B. Di Micco, M. Dreucci, G. Felici, S. Fiore, P. Franzini, C. Gatti, P. Gauzzi, S. Giovannella, E. Graziani, M. Jacewicz, J. Lee-Franzini, M. Martemianov, M. Martini, P. Massarotti, S. Meola, S. Miscetti, G. Morello, M. Moulson, S. Muller, M. Napolitano, F. Nguyen, M. Palutan, A. Passeri, V. Patera, I. Prado Longhi, P. Santangelo, B. Sciascia, M. Silarski, T. Spadaro, C. Taccini, L. Tortora, G. Venanzoni, R. Versaci, G. Xu, J. Zdebik, as members of the KLOE-2 collaboration, :, D. Babusci, D. Badoni, V. Bocci, A. Budano, S. A. Bulychjev, P. Campana, E. Dané, G. De Robertis, D. Domenici, O. Erriquez, G. Fanizzi, F. Gonnella, F. Happacher, B. Höistad, E. Iarocci, T. Johansson, V. Kulikov, A. Kupsc, F. Loddo, M. Matsyuk, R. Messi, D. Moricciani, P. Moskal, A. Ranieri, I. Sarra, M. Schioppa, A. Sciubba, W. Wiślicki, M. Wolke

**Category:**High Energy Physics - Experiment

We report the measurement of the ratio $\Gamma(\eta \to \pi^+\pi^-\gamma)/\Gamma(\eta \to \pi^+\pi^-\pi^0)$ analyzing a large sample of $\phi \to \eta \gamma$ decays recorded with the KLOE experiment at the DA$\Phi$NE $e^+ e^-$ collider, corresponding to an integrated luminosity of 558 pb$^{-1}$. The $\eta \to \pi^+\pi^-\gamma$ process is supposed to proceed both via a resonant contribution, mediated by the $\rho$ meson, and a non resonant direct term, connected to the box anomaly. The presence of the direct term affects the partial width value. Read More

**Authors:**The KLOE-2 Collaboration, F. Archilli, D. Babusci, D. Badoni, I. Balwierz, G. Bencivenni, C. Bini, C. Bloise, V. Bocci, F. Bossi, P. Branchini, A. Budano, S. A. Bulychjev, P. Campana, G. Capon, F. Ceradini, P. Ciambrone, E. Czerwinski, E. Dane, E. De Lucia, G. De Robertis, A. De Santis, G. De Zorzi, A. Di Domenico, C. Di Donato, D. Domenici, O. Erriquez, G. Fanizzi, G. Felici, S. Fiore, P. Franzini, P. Gauzzi, S. Giovannella, F. Gonnella, E. Graziani, F. Happacher, B. Hoistad, E. Iarocci, M. Jacewicz, T. Johansson, V. Kulikov, A. Kupsc, J. Lee-Franzini, F. Loddo, M. Martemianov, M. Martini, M. Matsyuk, R. Messi, S. Miscetti, G. Morello, D. Moricciani, P. Moskal, F. Nguyen, A. Passeri, V. Patera, I. Prado Longhi, A. Ranieri, P. Santangelo, I. Sarra, M. Schioppa, B. Sciascia, A. Sciubba, M. Silarski, C. Taccini, L. Tortora, G. Venanzoni, R. Versaci, W. Wislicki, M. Wolke, J. Zdebik

**Category:**High Energy Physics - Experiment

The processes $e^+e^-\to e^+e^-X$, with $X$ being either the $\eta$ meson or $\pi^0\pi^0$, are studied at DA$\Phi$NE, with $e^+e^-$ beams colliding at $\sqrt{s}\simeq1$ GeV, below the $\phi$ resonance peak. The data sample is from an integrated luminosity of 240 pb$^{-1}$, collected by the KLOE experiment without tagging of the outgoing $e^+e^-$. Preliminary results are presented on the observation of the $\gamma\gamma\to\eta$ process, with both $\eta\to\pi^+\pi^-\pi^0$ and $\eta\to\pi^0\pi^0\pi^0$ channels, and the evidence for $\gamma\gamma\to\pi^0\pi^0$ production at low $\pi^0\pi^0$ invariant mass. Read More

**Authors:**KEDR Collaboration, V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, O. L. Beloborodova, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, D. N. Grigoriev, Yu. M. Glukhovchenko, V. V. Gulevich, D. V. Gusev, S. E. Karnaev, G. V. Karpov, S. V. Karpov, T. A. Kharlamova, V. A. Kiselev, V. V. Kolmogorov, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. N. Kudryavtsev, V. F. Kulikov, G. Ya. Kurkin, E. A. Kuper, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, A. S. Medvedko, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, I. O. Orlov, A. A. Osipov, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, A. O. Poluektov, V. G. Prisekin, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, V. V. Smaluk, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, A. N. Yushkov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

We report results of a search for narrow resonances in e+ e- annihilation at center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR detector at the VEPP-4M e+ e- collider. Read More

**Authors:**F. Archilli, D. Babusci, D. Badoni, I. Balwierz, G. Bencivenni, C. Bini, C. Bloise, V. Bocci, F. Bossi, P. Branchini, A. Budano, S. A. Bulychjev, P. Campana, G. Capon, F. Ceradini, P. Ciambrone, E. Czerwinski, E. Dane', E. De Lucia, G. De Robertis, A. De Santis, G. De Zorzi, A. Di Domenico, C. Di Donato, D. Domenici, O. Erriquez, G. Fanizzi, G. Felici, S. Fiore, P. Franzini, P. Gauzzi, S. Giovannella, F. Gonnella, E. Graziani, F. Happacher, B. Hoistad, E. Iarocci, M. Jacewicz, T. Johansson, V. Kulikov, A. Kupsc, J. Lee-Franzini, F. Loddo, M. Martemianov, M. Martini, M. Matsyuk, R. Messi, S. Miscetti, G. Morello, D. Moricciani, P. Moskal, F. Nguyen, A. Passeri, V. Patera, I. Prado Longhi, A. Ranieri, P. Santangelo, I. Sarra, M. Schioppa, B. Sciascia, A. Sciubba, M. Silarski, C. Taccini, L. Tortora, G. Venanzoni, R. Versaci, W. Wislicki, M. Wolke, J. Zdebik

**Category:**High Energy Physics - Experiment

The existence of a secluded gauge sector could explain several puzzling astrophysical observations. This hypothesis can be tested at low energy e+e- colliders such as DAPHNE. Preliminary results obtained with KLOE data and perpectives for the KLOE-2 run, where a larger data sample is expected, are discussed. Read More

**Authors:**The KLOE Collaboration, F. Ambrosino, A. Antonelli, M. Antonelli, F. Archilli, I. Balwierz, G. Bencivenni, C. Bini, C. Bloise, S. Bocchetta, F. Bossi, P. Branchini, G. Capon, T. Capussela, F. Ceradini, P. Ciambrone, E. Czerwinski, E. DeLucia, A. DeSantis, P. DeSimone, G. DeZorzi, A. Denig, A. DiDomenico, C. DiDonato, B. DiMicco, M. Dreucci, G. Felici, S. Fiore, P. Franzini, C. Gatti, P. Gauzzi, S. Giovannella, E. Graziani, M. Jacewicz, J. Lee-Franzini, M. Martemianov, M. Martini, P. Massarotti, S. Meola, S. Miscetti, G. Morello, M. Moulson, S. Muller, M. Napolitano, F. Nguyen, M. Palutan, A. Passeri, V. Patera, I. PradoLonghi, P. Santangelo, B. Sciascia, M. Silarski, T. Spadaro, C. Taccini, L. Tortora, G. Venanzoni, R. Versaci, G. Xu, J. Zdebik, as members of the KLOE-2 collaboration, :, D. Babusci, D. Badoni, V. Bocci, A. Budano, S. A. Bulychjev, P. Campana, E. Dane, G. DeRobertis, D. Domenici, O. Erriquez, G. Fanizzi, F. Gonnella, F. Happacher, B. Hoistad, E. Iarocci, T. Johansson, V. Kulikov, A. Kupsc, F. Loddo, M. Matsyuk, R. Messi, D. Moricciani, P. Moskal, A. Ranieri, I. Sarra, M. Schioppa, A. Sciubba, W. Wislicki, M. Wolke

**Category:**High Energy Physics - Experiment

We report the first observation of the rare eta->e+e-e+e- decay based on 1.7 fb^{-1} collected by the KLOE experiment at the DAFNE phi-factory. The selection of the e+e-e+e- final state is fully inclusive of radiation. Read More

A necessary condition for uniqueness of factorizations of elements of a finite group $G$ with factors belonging to a union of some conjugacy classes of $G$ is given. This condition is sufficient if the number of factors belonging to each conjugacy class is big enough. The result is applied to the problem on the number of irreducible components of the Hurwitz space of degree $d$ marked coverings of $\mathbb P^1$ with given Galois group $G$ and fixed collection of local monodromies. Read More

For any reduced curve $C\subset \mathbb P^2$, we define the notions of the number of its virtual cusps $c_v$ and the number of its virtual nodes $n_v$ which are non-negative, coincide respectively with the numbers of ordinary cusps and nodes in the case of cuspidal curves, and if $\hat C$ is the dual curve of an irreducible curve $C$ and $\hat n_v$ and $\hat c_v$ are the numbers of its virtual nodes and virtual cusps, then the integers $c_v$, $n_v$, $\hat c_v$, $\hat n_v$ satisfy Classical Pl\"{u}cker's formulae. Read More

**Authors:**V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, I. V. Bedny, O. L. Beloborodova, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, Yu. M. Glukhovchenko, V. V. Gulevich, D. V. Gusev, S. E. Karnaev, G. V. Karpov, S. V. Karpov, T. A. Kharlamova, V. A. Kiselev, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. F. Kulikov, G. Ya. Kurkin, E. A. Kuper, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, A. S. Medvedko, O. I. Meshkov, A. I. Milstein, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, I. O. Orlov, A. A. Osipov, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, A. O. Poluektov, D. N. Shatilov, G. E. Pospelov, V. G. Prisekin, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, Yu. I. Skovpen, A. N. Skrinsky, V. V. Smaluk, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, A. N. Yushkov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

**Category:**High Energy Physics - Experiment

We present a study of the inclusive photon spectrum from 6.3 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of the radiative decay J/psi -> eta_c gamma, eta_c width and mass. Read More

This article is a continuation of the article with the same title (see arXiv:1003.2953v1). Let {\rm $\text{HUR}_{d,t}^{G}(\mathbb P^1)$} be the Hurwitz space of degree $d$ coverings of the projective line $\mathbb P^1$ with Galois group $\mathcal S_d$ and having fixed monodromy type $t$ consisting of a collection of local monodromy types (that is, a collection of conjugacy classes of permutations $\sigma$ of the symmetric group $\mathcal S_d$ acting on the set $I_d=\{1,. Read More