Browsing by Author "Sundu, H."
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Article Citation Count: 75Analysis of Pc+(4380) and Pc+(4450) as pentaquark states in the molecular picture with QCD sum rules(Amer Physical Soc, 2017) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupTo better understand the nature and internal structure of the exotic states discovered by many collaborations, more information on their electromagnetic properties and their strong and weak interactions with other hadrons is needed. The residue or current coupling constant of these states together with their mass are the main inputs in determinations of such properties. We perform QCD sum rules analyses on the hidden-charm pentaquark states with spin parities J(P) = 3/2 (+/-) and J(P) = 5/2 (+/-) to calculate their residue and mass. In the calculations, we adopt a molecular picture for J(P) = 3/2(+/-) states and a mixed current in a molecular form for J(P) = 5/2(+/-). Our analyses show that the P-c(+) (4380) and P-c(+) (4450), observed by the LHCb Collaboration, can be considered as hidden-charm pentaquark states with J(P) = 3/2(-) and JP = 5/2(+), respectively.Conference Object Citation Count: 2Analysis of the semileptonic transition of heavy ΞQ baryon to Ξ baryon in Light Cone QCD Sum Rules(Elsevier Science Bv, 2013) Saraç Oymak, Yasemin; Azizi, K.; Sundu, H.; Physics GroupThis study presents the analysis of form factor calculations of semileptonic transitions of heavy baryons via light cone QCD sum rules. The work covers the semileptonic transitions of the Xi(b) and Xi(c) baryons. The form factors for the transitions Xi(b) -> Xi l(+)l(-) and Xi(c) -> Xi lv are obtained using their currents in the most general form. The obtained form factors are also used to calculate the decay widths and branching ratios of the considered transitions.Article Citation Count: 10Analysis of the strong D2* (2460)0 → D+ π- and Ds2*(2573)+ → D+ K0 transitions via QCD sum rules(Springer, 2014) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupThe strong D-2* (2460)(0) -> D+ pi(-) and D-s2* (2573)(+) -> D+ K-0 transitions are analyzed via three-point QCD sum rules. First we calculate the corresponding strong coupling constants g(D2)*D pi and g(Ds2)*DK. Then we use them to calculate the corresponding decay widths and branching ratios. Making use of the existing experimental data on the ratio of the decay width in the pseudoscalar D channel to that of the vector D* channel, finally, we estimate the decay width and branching ratio of the strong D-2(*) (2460)(0) -> D*(2010)(+)pi(-) transition.Article Citation Count: 12Determination of the possible quantum numbers for the newly observed Ξb(6227)0 state(Springer, 2021) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupThe LHCb Collaboration recently reported the observation of a new excited bottom baryon Xi(b)(6227)(0) and announced an improvement in the measurements related to the previously observed Xi(b)(6227)(-) state. We conduct an analysis for Xi(b)(6227)(0) state considering it as isospin partner of the Xi(b)(6227)(-) resonance and possibly 1P or 2S excited state with spin J = 3/2. The corresponding masses for both possibilities have consistent results with the experimental data, indicating that only with the mass sum rules, one can not make exact decision on the nature and quantum numbers of this state. To go further, the decays of these possible excited states to Xi(-)(b)pi(+) final state are also considered and the relevant strong coupling constants are extracted from the light cone sum rules. The obtained decay width values support the possibility of Xi(b)(6227)(0) to be the 1P excited state of Xi(b)(5945)(0) baryon.Article Citation Count: 31Determination of the quantum numbers of Σb(6097)± via their strong decays(Amer Physical Soc, 2019) Saraç Oymak, Yasemin; Azizi, K.; Sarac, Y.; Sundu, H.; Physics GroupRecent experimental progress has led to the detection of many new hadrons. Very recently, the LHCb Collaboration announced the observation of two new Sigma(b)(6097)(+/-) states in the Lambda(0)(b)pi(+/-) invariant mass distribution, which are considered to be the excited states of the ground-state Sigma((*))(b) baryon. Although almost all of the ground-state baryons have been observed, the fact that only a limited number of excited states have been observed makes them intriguing. Understanding the properties of the excited baryons would improve our knowledge about the strong interaction, as well as the nature and internal structures of these baryons. To specify the quantum numbers of the Sigma(+/-)(b(6097)) states, we analyze their strong decays to Lambda(0)(b) and pi(+/-) within the light-cone QCD sum rules formalism. To this end, they are considered as possible 1P or 2S excitations of either the ground-state Sigma(b) baryon with J = 1/2 or the Sigma(b)* baryon with J = 3/2, and their corresponding masses are calculated. The results of the analyses indicate that the Sigma(b)(6097)(+/-) baryons are excited 1P baryons with quantum numbers J(P) = 3-/2.Article Citation Count: 10FCNC transitions of Λb,c to nucleon in SM(Iop Publishing Ltd, 2010) Saraç Oymak, Yasemin; Bayar, M.; Sarac, Y.; Sundu, H.; Physics GroupWe provide a comprehensive study of semileptonic flavor-changing neutral current transitions for Lambda(b) -> nl(+) l(-) and Lambda(c) -> pl(+) l(-) in the context of light cone QCD sum rules. Using the most general form of the interpolating current for Lambda(b),(c), as well as nucleon distribution amplitudes, we calculate all 12 form factors entering the calculations in full theory. We obtain the order of heavy quark effective theory violation and argue that the Lambda(b) -> nl(+) l(-) case can be studied at LHC, but the other one has a very small branching ratio.Article Citation Count: 24Hidden bottom pentaquark states with spin 3/2 and 5/2(Amer Physical Soc, 2017) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupTheoretical investigations of the pentaquark states that were recently discovered provide important information on their nature and structure. It is necessary to study the spectroscopic parameters, like masses and residues of particles belong to the class of pentaquarks, and ones having similar structures. The mass and pole residue are quantities that emerge as the main input parameters in exploration of the electromagnetic strong and weak interactions of the pentaquarks with other hadrons in many frameworks. This work deals with a QCD sum rule analysis of the spin-3/2 and spin-5/2 bottom pentaquarks with both positive and negative parities aiming to evaluate their masses and residues. In calculations, the pentaquark states are modeled by molecular-type interpolating currents: for particles with J = 5/2, a mixing current is used. We compare the results obtained in this work with the existing predictions of other theoretical studies. The predictions on the masses may shed light on experimental searches of the bottom pentaquarks.Article Citation Count: 26Interpretation of the newly discovered Ω(2012)(Amer Physical Soc, 2018) Saraç Oymak, Yasemin; Azizi, K.; Sarac, Y.; Sundu, H.; Physics GroupVery recently, Belle Collaboration reported observation of a narrow state called Omega(2012) with mass 2012.4 +/- 0.7(stat) +/- 0.6(syst) MeV and width 6.4(-2.0)(+2.5)(stat) +/- 1.6(syst) MeV. We calculate the mass and residue of the Omega(2012) state by employing the QCD sum rule method. Comparison of the obtained results with the experimental data allows us to interpret this state as a 1P orbital excitation of the ground state Omega baryon, i.e., with quantum numbers J(P) = 3-\2.Article Citation Count: 5Interpretation of the Λc(2910)+ baryon newly seen by Belle Collaboration and its possible bottom partner(Springer, 2022) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupThe developments in the experimental facilities and analyses techniques have recently lead to the observation of many hadronic states ranging from excitations of conventional hadrons to various exotic states. The baryons with single heavy quark are among these states providing an attractive field of research to get a better understanding of the nonperturbative nature of the strong interaction. Recently, the Belle Collaboration announced observation of the state Lambda(c)(2910)(+) with a mass 2913.8 +/- 5.6 +/- 3.8 MeV/c(2) and width 51.8 +/- 20.0 +/- 18.8 MeV. In the present study, by the mass analyses of different excitations at A c channel and their comparison with existing experimental information, we find that the spin-parity of this newly found excited state is J(P) = 1/2(-) and it is a 2 P state denoting by Lambda(c)(1/2(-), 2 P). We predict its current coupling as well, which can be served as one of the main input parameters to investigate different decays and interactions of this particle. We also determine the mass and current coupling of Lambda(b)(1/2(-), 2 P) as possible bottom counterpart of the new Lambda(c)(2910)(+) state, which may be in agenda of different experiments in near future.Article Citation Count: 35Investigation of Pcs(4459)0 pentaquark via its strong decay to ΛJ/Ψ(Amer Physical Soc, 2021) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupRecently the observation of a new pentaquark state, the hidden-charmed strange P-cs(4459)(0), was reported by the LHCb Collaboration. The spin-parity quantum numbers of this state were not determined as a result of insufficient statistics. To shed light on its quantum numbers, we investigate its decay, P-cs(4459)(0) -> J/Psi Lambda, the mode that this state has been observed, within the QCD sum rule framework. We obtain the width of this decay assigning the spin-parity quantum numbers of the P-cs(4459)(0) state as J(P) = 1-/2 and its substructure as diquark-diquark-antiquark. To this end, we first calculate the strong coupling constants defining the considered decay and then use them in the width calculations. The obtained width is consistent with the experimental observation, confirming the quantum numbers J(P) = 1-/2 and compact pentaquark nature for the P-cs(4459)(0) state.Article Citation Count: 7Investigation of a candidate spin-1/2 hidden-charm triple strange pentaquark state Pcsss(Amer Physical Soc, 2023) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupA candidate triple strange pentaquark state, P-csss, is investigated through its strong decay channel P-csss -> C2-J=y/. To calculate the relevant strong coupling constants, two possible interpolating currents with spin-parity JP 1/4 1 - are used. Though the chosen currents for the state under consideration have spin-parity quantum numbers JP 1/4 1 -, they couple to both the positive and negative parity states simultaneously and the corresponding decay widths are obtained for both parities. These widths are obtained as foP(csss) -> J=y/C2- +/_ 1/4 201.4 82.5 MeV for the negative and fo P similar to csss -> J=y/C2- +/_ 1/4 316.4 107.8 MeV for the positive parity state when the first current is used. For the second current, we obtain foP(csss) -> J=y/C2- +/_ 1/4 252.5 116.7 MeV for the negative and fo P similar to csss -> J=y/C2- +/_ 1/4 361.1 ; 98.4 MeV for the positive parity state. These results may provide insights into future experimental observations of such candidate states and help to distinguish and fix their properties.Article Citation Count: 0Investigation of full-charm and full-bottom pentaquark states(Springer, 2024) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupThe continuous advancement of experimental techniques and investigations has led to observations of various exotic states in particle physics. Each addition to this family of states not only raises expectations for future discoveries but also focuses attention on such potential new states. Building upon this motivation and inspired by recent observations of various traditional and exotic particles containing an increased number of heavy quarks, our study provides a spectroscopic search for potential pentaquark states with spin-parity 32-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{3}{2}<^>-$$\end{document} and composed entirely of charm or bottom quarks. We predict the masses for full-charm and full-bottom pentaquark states as m=7628 +/- 112\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$m = 7628 \pm 112$$\end{document} MeV and m=21,982 +/- 144\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$m = 21,982 \pm 144$$\end{document} MeV, respectively. We also compute the current couplings of these states to vacuum, which are main inputs in investigations of their various possible decays.Article Citation Count: 11Investigation of hidden-charm double strange pentaquark candidate Pcss via its mass and strong decays(Springer, 2022) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupThis work presents an analysis of a hidden charmed pentaquark candidate state with double strange quark in its quark content. The investigation is performed in two parts, which provide the mass prediction of the considered state and its partial decay widths for the P-css -> Xi(0) J/psi and P-css -> Xi D-+(c)s(-) channels. For the analyses, two-point and three-point QCD sum rule methods are applied to get the mass and the widths, respectively. The mass for this candidate state is obtained as m p(css) = 4600 +/- 155 MeV with corresponding current coupling constant lambda p(css)= (0.81 +/- 0.21) x 10(-3) GeV6. These results are used in the analysis of the partial widths of this state for the decays P-css -> Xi(0)J/psi and P-css -> Xi D-+(c)s(-). From these decays, the total width is obtained as Gamma = 12.29 +/- 2.94 MeV. These results may shed light on the future experimental searches in which such types of states are probed and may provide information to discriminate between such possible observations.Article Citation Count: 2Investigation of the Bc → χc2l(ν)over bar- transition via QCD sum rules(Springer, 2013) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupWe calculate the transition form factors of the semileptonic in the framework of QCD sum rules taking into account the two-gluon condensate corrections. Using the obtained results of form factors we estimate the decay widths and branching ratios related to this transition at all lepton channels. A comparison of the obtained results with the predictions of other non-perturbative approaches are also made. The orders of branching ratios for different lepton channels indicate that the transition can be studied at LHC using the collected or future data.Conference Object Citation Count: 1Investigation of the Ds2*(2573)+D+K0 vertex via QCD sum rules(Iop Publishing Ltd, 2014) Saraç Oymak, Yasemin; Azizi, K.; Sundu, H.; Physics GroupIn this work the D-s2*(2573)+D+K-0 vertex is studied and the coupling constant corresponding to the D-s2*(2573)(+) -> (D+K0) transition is calculated. The calculation is performed using three point QCD sum rules method and the value of the coupling constant is obtained as gD(s2)*(DK) = (12.85 +/- 3.85) GeV-1. The coupling constant is also used to calculate the decay width and the branching ratio of the considered transition.Article Citation Count: 3Investigation of the strange pentaquark candidate PΛψsð4338þ0 recently observed by LHCb(Amer Physical Soc, 2023) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupThe recently observed strange pentaquark candidate, P Lambda yso4338 thorn 0, is investigated to provide information about its nature and substructure. To this end, its mass and width through the decay channels P Lambda yso4338 thorn 0 -> J=y Lambda and P Lambda yso4338 thorn 0 -> ric Lambda are calculated by applying two- and three-point QCD sum rules, respectively. The state is considered as a Xi c D over bar meson-baryon molecular structure with spin-parity quantum numbers JP 1/4 1 -. The obtained mass, mP Lambda 2 yso4338 thorn 0 1/4 4338 130 MeV, and width, Gamma P Lambda yso4338 thorn 0 1/4 10.40 1.93 MeV, are consistent with the experimental data within the presented uncertainties. This allows us to assign a Xi c D over bar molecular structure of JP 1/4 1 - for the P Lambda yso4338 thorn 0 state.Article Citation Count: 0Investigation of Λ (1405)as a molecular pentaquark state(Springer, 2024) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupLambda ( 1405 ) is one of the interesting particles with its unclear structure and distinct properties. It has a light mass compared to its non-strange counterpart, despite the strange quark it carries. This situation puts the investigation of this resonance among the hot topics in hadron physics and collects attention to clarify its properties. In this study, we focus on the calculation of the mass and residue of the Lambda ( 1405 ) resonance within the framework of QCD sum rules. We assign a structure in the form of a molecular pentaquark composed from admixture of K - meson-neutron. Using an interpolating current in this form, the masses and the current coupling constant are attained as m = 1406 +/- 128 MeV and lambda = ( 3.35 +/- 0.35 ) x 10( - 5) GeV 6 for q and m = 1402 +/- 141 MeV and lambda = ( 4.08 +/- 1.08 ) x 10( - 5) GeV 6 for I Lorentz structures entering the calculations, respectively. The obtained mass values agree well with the experimental data supporting the plausibility of the considered structure.Article Citation Count: 0Investigations of Λ states with spin-parity 3 ± 2(Amer Physical Soc, 2024) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupThe present study provides spectroscopic investigations of spin-32 A baryons with both positive and negative parities. The analysis mainly focuses on three states, namely 1P, 2P, and 2S, and corresponding masses are calculated using the QCD sum rule method. To implement the method, we apply two types of interpolating currents with octet and singlet quantum numbers and compare the corresponding results with the reported masses of experimentally observed states. From the comparisons, it is extracted that the results of interpolating current with octet quantum numbers are in good agreement with the experimentally measured masses. The masses obtained with this interpolating current are m = 1513.64 +/- 8.76 MeV for 1P state with JP = 3 -, m' = 1687.91 +/- 0.31 MeV for 2P state with JP = 3 - and m = 1882.37 +/- 11.95 MeV for 2S state with JP = 3 + and they are consistent with the experimental masses of A(1520), A(1690), and A(1890), respectively, which confirm their spin-parity quantum numbers. Besides, we calculate the corresponding current coupling constants, which are utilized as inputs in the calculations of different form factors defining the widths of the states under study.Article Citation Count: 24Lepton flavor universality violation in semileptonic tree level weak transitions(Amer Physical Soc, 2019) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupThe recent deviations of the experimental data on some parameters of the tree-level semileptonic B and B-c mesons decays from the standard model (SM) predictions indicate considerable violations of the lepton flavor universality, and as a result possible new physics (NP) effects. To better understand the possible NP effects it is necessary to study deeply the physical quantities defining these decays from many aspects. The calculations of the physical quantities require the determinations of the hadronic form factors entering the matrix elements of the considered transitions as the main inputs. We calculate the form factors governing the tree-level B-c -> J/psi l nu and B-c -> eta(c)l nu transitions within the QCD sum rules method. The obtained form factors are used in the calculations of the branching ratios (BRs) of the B-c -> J/psi l nu and B-c -> eta(c)l nu transitions as well as R(J/psi) and R(eta(c)). Our result on R(J/psi) supports the present tension between the SM theory prediction and the experimental data. Our result on R(eta(c)) can be checked in future experiments.Article Citation Count: 38Light cone QCD sum rules study of the semileptonic heavy ΞQ and ΞQ′ transitions to Ξ and Σ baryons(Springer, 2012) Saraç Oymak, Yasemin; Sarac, Y.; Sundu, H.; Physics GroupThe semileptonic decays of heavy spin-1/2, Xi(b(c)) and Xi(b(c))' baryons to the light spin-1/2, Xi and S baryons are investigated in the framework of light cone QCD sum rules. In particular, using the most general form of the interpolating currents for the heavy baryons as well as the distribution amplitudes of the Xi and Sigma baryons, we calculate all form factors entering the matrix elements of the corresponding effective Hamiltonians in full QCD. Having calculated the responsible form factors, we evaluate the decay rates and branching fractions of the related transitions.