Search results for "Upsilon"
showing 10 items of 71 documents
"Table 16" of "Inclusive $\Upsilon$ production in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV"
2020
$\Upsilon$(3S) $R_{\rm pPb}$ values at $\sqrt{s_{\rm NN}}$ = 8.16 TeV. The first uncertainty is statistical, the second is the uncorrelated systematic, while the third one is a correlated systematic uncertainty.
"Table 7" of "Inclusive $\Upsilon$ production in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV"
2020
Ratio of $\Upsilon$(3S) over $\Upsilon$(1S) yields in p--Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV .The first uncertainty is statistical, while the second is the systematic.
Search for Production of Invisible Final States in Single-Photon Decays of Υ(1S)
2010
We search for single-photon decays of the Upsilon(1S) resonance, Upsilon->gamma+invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A0, or a pair of dark matter particles, chi chi-bar. Both A0 and chi are assumed to have zero spin. We tag Upsilon(1S) decays with a dipion transition Upsilon(2S)->pi+pi-Upsilon(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m_A0<=9.2 GeV and m_chi<=4.5 GeV in the sample of 98e6 Upsilon(2S) decays collected with the BaBar detector and set stringent limits on new physics models that contain light dark ma…
Measurement of upsilon production in 7 TeV pp collisions at ATLAS
2013
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM
Measurement of the chi(b) (3 P) mass and of the relative rate of chi(b1) (1 P) and chi(b2) (1 P) production
2014
The production of $\chi_b$ mesons in proton-proton collisions is studied using a data sample collected by the LHCb detector, at centre-of-mass energies of $\sqrt{s}=7$ and $8$ TeV and corresponding to an integrated luminosity of 3.0 fb$^{-1}$. The $\chi_b$ mesons are identified through their decays to $\Upsilon(1S)\gamma$ and $\Upsilon(2S)\gamma$ using photons that converted to $e^+e^-$ pairs in the detector. The $\chi_b(3P)$ meson mass, and the relative prompt production rate of $\chi_{b1}(1P)$ and $\chi_{b2}(1P)$ mesons as a function of the $\Upsilon(1S)$ transverse momentum in the $\chi_b$ rapidity range 2.0< $y$<4.5, are measured. Assuming a mass splitting between the $\chi_{b1}(3P)$ an…
Search for a low-mass scalar Higgs boson decaying to a tau pair in single-photon decays of Y(1S)
2013
We search for a low-mass scalar CP-odd Higgs boson, A(0), produced in the radiative decay of the upsilon resonance and decaying into a tau(+)tau(-) pair: Y(1S) -> gamma A(0). The production of Y(1S) mesons is tagged by Y(2S) -> pi(+)pi(-) Y(1S) transitions, using a sample of (98.3 +/- 0.9) x 10(6) Y(2S) mesons collected by the BABAR detector. We find no evidence for a Higgs boson in the mass range 3: 5 <= m(A)0 <= 9: 2 GeV, and combine these results with our previous search for the tau decays of the light Higgs in radiative Y(3S) decays, setting limits on the coupling of A(0) to the b (b) over bar quarks in the range 0.09-1.9. Our measurements improve the constraints on the parameters of th…
"Table 17" of "Inclusive $\Upsilon$ production in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV"
2020
Ratio of $\Upsilon$(2S) to $\Upsilon$(1S) $R_{\rm pPb}$ at $\sqrt{s_{\rm NN}}$ = 8.16 TeV as a function of $y_{\rm cms}$ .The first uncertainty is statistical, while the second is the systematic.
"Table 6" of "Inclusive $\Upsilon$ production in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV"
2020
Ratio of $\Upsilon$(2S) over $\Upsilon$(1S) yields in p--Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV .The first uncertainty is statistical, while the second is the systematic.
"Table 18" of "Inclusive $\Upsilon$ production in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV"
2020
Ratio of $\Upsilon$(3S) to $\Upsilon$(1S) $R_{\rm pPb}$ at $\sqrt{s_{\rm NN}}$ = 8.16 TeV as a function of $y_{\rm cms}$ .The first uncertainty is statistical, while the second is the systematic.
Quarkonium suppression in heavy-ion collisions: an open quantum system approach
2016
We address the evolution of heavy-quarkonium states in an expanding quark-gluon plasma by implementing effective field theory techniques in the framework of open quantum systems. In this setting we compute the nuclear modification factors for quarkonia that are $S$-wave Coulombic bound states in a strongly-coupled quark-gluon plasma. The calculation is performed at an accuracy that is leading-order in the heavy-quark density expansion and next-to-leading order in the multipole expansion. The quarkonium density-matrix evolution equations can be written in the Lindblad form, and, hence, they account for both dissociation and recombination. Thermal mass shifts, thermal widths and the Lindblad …