• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Scalar Hidden-Charm Tetraquark States with QCD Sum Rules?

    2018-05-23 06:03:55ZunYanDi狄尊燕ZhiGangWang王志剛JunXiaZhang張君霞andGuoLiangYu于國梁
    Communications in Theoretical Physics 2018年2期
    關(guān)鍵詞:王志剛

    Zun-Yan Di(狄尊燕)Zhi-Gang Wang(王志剛)? Jun-Xia Zhang(張君霞)and Guo-Liang Yu(于國梁)

    1Department of Physics,North China Electric Power University,Baoding 071003,China

    2School of Nuclear Science and Engineering,North China Electric Power University,Beijing 102206,China

    1 Introduction

    In recent years,a number of charged charmoniumlike(bottomonium-like)exotic states have been observed,such as theZc(3900),Zc(4020),Zc(4050),Zc(4055),Zc(4200),Zc(4240),Zc(4250),Z(4430),Zb(10610),andZb(10650).[1]Ifthosecharged charmonium-like(bottomonium-like)states are resonances indeed,their quark constituents must beirrespective of the diquark-antidiquark type or mesonmeson type substructures.

    Those exotic states cannot be accommodated within the naive quark model,and represent a new facet of QCD and provide a new opportunity for a deeper understanding of the non-perturbative QCD.The QCD sum rules method is a powerful tool in studying the hidden-charm(bottom)tetraquark or molecular states and hidden-charm pentaquark states.[2?4]In the QCD sum rules,the operator product expansion is used to expand the time-ordered currents into a series of quark and gluon condensates,which parameterize the non-perturbative properties of the QCD vacuum.Based on the quark-hadron duality,we can obtain copious information about the hadronic parameters at the phenomenological side.[5?6]

    The diquarkshave fi ve structures in Dirac spinor space,whereandCσμνfor the scalar,pseudoscalar,vector,axialvector and tensor diquarks,respectively.In this expression,qjdenotes the quark field;i,jandkare color indexes;Cis the charge conjugation matrix;and the superscript T denotes the transpose of the Dirac indexes.The attractive interactions of one-gluon exchange favor formation of the diquarks in color antitriplet, fl avor antitriplet and spin singlet,[7]while the favored con fi gurations are the scalar(Cγ5)and axialvector(Cγμ)diquark states.[8?9]We can construct the diquark-antidiquark type hidden charm tetraquark states,[10]

    to study the scalar tetraquark states having larger masses.

    In this article,we constructC?Candtype currents to explore the charged scalar hidden-charm tetraquark states by calculating the contributions of the vacuum condensates up to dimension-10 in a consistent way.

    This article is organized as follows:in Sec.2,we derive the QCD sum rules to extract the masses and pole residues of the charged scalarcuˉcˉd(cuˉcˉs)tetraquark states;in Sec.3,we present the numerical results and discussions;section 4 is reserved for conclusion.

    2 QCD Sum Rules for the Scalar Hidden-Charm Tetraquark States

    In QCD sum rules,we consider the two-point correlation functions Π1,2,3,4(p),

    where theJ1,2,3,4(x)are the interpolating currents with the same quantum numbers as the tetraquark states we want to study.Those currents are constructed in the diquark model and can be written as,

    On the phenomenological side,we insert a complete set of intermediate hadronic states with the same quantum numbers as the current operatorsJ1,2,3,4(x)into the correlation functions Π1,2,3,4(p)to obtain the hadronic representations.[5?6]After isolating the ground state contributions of the scalar tetraquark states,we get the following results,

    At the quark level,the two-point correlation functions Π1,2,3,4(p)can be evaluated via the operator product expansion method.We contract theu,d,candsquark fields with the wick theorem and obtain the following results:

    where theUij(x),Dij(x),Sij(x),andCij(x)are the fullu,d,s,andcquark propagators,respectively.For simplicity,theUij(x)andDij(x)can be written asPij(x),

    andis the Gell-Mann matrix,Dα=In Eqs.(13)–(14),we retain the termsand>originate from the Fierz re-arrangement of the>to absorb the gluons emitted from the heavy quark lines so as to extract the mixed condensates and four-quark condensatesrespectively.We compute the integrals both in the coordinate and momentum spaces by taking into account the contributions of the vacuum condensates up to dimension-10.Then,we obtain the QCD spectral densities from the imaginary parts of the correlations.

    After getting the QCD spectral densities,we take the quark-hadron duality below the continuum thresholdss0and perform the Borel transformation with respect to the variableP2=?p2to obtain the QCD sum rules,

    the explicit expressions of the spectral densitiesρ1,2,3,4(s)are given in the appendix.The subscripts 0,3,4,5,6,7,8,10 denote the dimensions of the vacuum condensates.We take into account the vacuum condensates,which are vacuum expections of the operators of the orderswithk≤1 consistently.

    We derive Eq.(17)with respect to 1/T2,then eliminate the pole residuesλZ1,2,3,4,and obtain the expressions for the masses of the scalar tetraquark states,

    Once the masses are obtained,we can take them as input parameters and obtain the pole residues from the QCD sum sules in Eq.(17).

    3 Numerical Results and Discussions

    In this section,we perform the numerical analysis,and choose the reasonable QCD parameters for the quark masses and vacuum condensates.The vacuum condensates are taken to be the standard values

    at the energy scaleThe quark condensates and mixed quark condensates evolve with the renormalization group equation,

    In addition,we take the valuesmu(μ=1 GeV)=md(μ=1 GeV)=mq(μ=1 GeV)=0.006 GeV from the Gell-Mann-Oakes-Renner relation,and choose themassmc(mc)=(1.275±0.025)GeV andms(μ=2 GeV)=(0.095±0.005)GeV from the Particle Data Group,[1]and take into account the energy-scale dependence of themasses from the renormalization group equation,

    for the flavorsnf=5,4 and 3,respectively.[1]

    The energy scaleμis considered as a variable.In Refs.[3–4],the energy scale dependence of the QCD sum rules for the hidden-charm tetraquark states and molecular states is studied in details for the first time,and an energy scale formula,

    with the effectivec-quark mass Mcis suggested.The formula works well for theX(3872),Zc(3885/3900),X?(3860),Y(3915),Zc(4020/4025),Z(4430),X(4500),Y(4630/4660),X(4700)in the scenario of tetraquark states.In this article,we take the updated value of the effectivec-quark mass Mc=1.82 GeV to determine the energy scales of the QCD spectral densities.[12]

    The mass gaps between the ground states and the first radial excited states are usually taken as(0.4?0.6)GeV.For examples,theZ(4430)is tentatively assigned to be the first radial excitation of theZc(3900)according to the analogous decays,and the mass differences576 MeV,theX(3915)andX(4500)are assigned to be the ground state and the first radial excited state of the axialvector-diquark-axialvectorantidiquark type scalartetraquark states,respectively,and their mass difference is588 MeV.[16]The relation

    serves as another constraint on the masses of the hiddencharm tetraquark states.In calculations,we observe that the values of the massesMZdecrease with increase of the energy scalesμfrom QCD sum rules in Eq.(19).While Eq.(21)indicates that the value of the massesMZincrease when the energy scalesμincrease.There exist optimal energy scales,which lead to reasonable massesMZ.

    We should obey two criteria to choose the Borel parametersT2and threshold parameterss0in numerical calculations.The first criterion is the pole dominance on the phenomenological side.The pole contribution(PC)is defined by,

    The second criterion is the convergence of the operator product expansion.To judge the convergence,we calculate the contributionsDiin the operator product expansion with the formula,

    where the indexidenotes the dimension of the vacuum condensates.

    In Fig.1,the contributions of the pole terms are plotted with variations of the Borel parametersT2for different values of the threshold parameterss0,where the values of energy scales are taken asμ=4.00 GeV,2.90 GeV,4.05 GeV and 2.95 GeV for the tetraquark statesZ1,Z2,Z3,Z4,respectively.From the fi gure,we can see that the continuum thresholds≤5.75 GeV,≤5.05 GeV for the tetraquark statesZ1,Z2,Z3,Z4respectively are too small to satisfy the pole dominance condition to result in reasonable Borel windows.

    Fig.1 The pole contributions with variations of the Borel parameters T2and threshold parameters s0.

    In Fig.2,the contributions of different condensate terms in the operator product expansion are plotted with the Borel parametersT2for the continuum thresholdsand 5.25 GeV at the energy scales,μ=4.00 GeV,2.90 GeV,4.05 GeV and 2.95 GeV for the tetraquark statesZ1,Z2,Z3,Z4,respectively.From the figure,we can see the contributionsDiexplicitly and choose reasonable Borel parameters.We take theZ1state as an example to illustrate the procedure.In that case,we observe that the perturbative term and the?ˉqq>term play an important role,while the other condensate terms play a minor important role.At the valueT2≤4.9 GeV2,the perturbative term andterm decrease monotonously and quickly with increase of theT2,which cannot lead to stable masses and pole residues.At the valueT2=(5.0–5.4)GeV2,the convergent behavior in the operator product expansion is very good and the perturbative term makes the main contribution.We present the optimal energy scalesμ,ideal Borel parametersT2,continuum threshold parameterss0and pole contributions in Table 1.From the Table,we can see that the two criteria of the QCD sum rules can be satisfied.

    We take into account all uncertainties of the input parameters,and obtain the masses and pole residues of the hidden-charm tetraquark states,which are shown explicitly in Figs.3–4 and Table 1.From Figs.3–4,we can see that the Borel platforms exist.On the other hand,from Table 1,we can see that the energy scale formulais well satisfied.We expect to make reasonable predictions,the present predictions can be confronted with the experimental data in the future.

    Table 1 The energy scales,Borel parameters,continuum threshold parameters,pole contributions,masses and pole residues for the scalar tetraquark states.

    Fig.2 The contributions of different terms in the operator product expansion with variations of the Borel parameters T2,where the 0,3,4,5,6,7,8,10 denote the dimensions of the vacuum condensates.

    In the following,we discuss the possible hadronic decay patterns of thescalar tetraquark states.Being composed of a diquark and antidiquark pair,a hidden-charm tetraquark state can decay very easily into a pair of open-charmDmesons or one charmonium state plus a light meson through quark rearrangement.The strong decays are Okubo-Zweig-Iizuka super-allowed.Under the restrictions of the symmetries and the masses of the studied scalar tetraquark states obtained in Table 1,the possible two-body strong decay channels are

    which are kinematically allowed.Theoretically,the mass of the ground state is lighter than the counterpart of its excited state,and the corresponding phase space is larger,thus the decay width of the resonance to the ground state is wider.This means that the ground state decay modes of the resonance can take place more easily.Besides,the excited sate is unstable,which brings some difficulty to the observation of the decay process for the resonance state.Consequently,the dominant decay modes of the scalar tetraquark states areWe can search for those scalar hidden-charm tetraquark states in those decay channels.

    Fig.3 The masses with variations of the Borel parameters T2.

    Fig.4 The pole residues with variations of the Borel parameters T2.

    4 Conclusion

    In this article,we study the pseudoscalar-diquarkpseudoscalar-antidiquark type and vector-diquark-vectorantidiquark type scalar hidden-charmtetraquark states with the QCD sum rules by calculating the contributions of the vacuum condensates up to dimension-10 in the operator product expansion.In numerical calculations,we use the energy scale formula

    to determine the ideal energy scales of the QCD spectral densities and search for the optimal Borel parametersT2and continuum thresholdss0to satisfy the two criteria of the QCD sum rules(i.e.pole dominance on the phenomenological side and convergence of the operator product expansion).We obtain the masses and pole residues of the scalar hidden-charmtetraquark states.The predicted masses are around(5.43–5.45)GeV for theC?Ctype tetraquark states and(4.64–4.67)GeV for thetype ones,which can be confronted with the experimental data in the future.Moreover,we discuss the possible hadronic decay patterns of the two types of tetraquark states,and list their dominant decays. As the predicted masses of thetype tetraquark states are lighter than the counterparts of theC?Ctype ones and the two types of tetraquark states have the same dominant decays,the widths of thetype tetraquark states are narrower.Therefore,thetype tetraquark states can be observed more easily,which can be testi fi ed in the future at the BESIII,LHCb,and Belle-II.

    Appendix

    The explicit expressions of the QCD spectral densitiesρ1,2,3,4(s),

    [1]C.Patrignani,et al.,Chin.Phys.C 40(2016)100001.

    [2]R.D.Matheus,S.Narison,M.Nielsen,and J.M.Richard,Phys.Rev.D 75(2007)014005;F.S.Navarra,M.Nielsen,and S.H.Lee,Phys.Lett.B 649(2007)166;Z.G.Wang,Eur.Phys.J.C 59(2009)675;Z.G.Wang,Eur.Phys.J.C 63(2009)115;J.R.Zhang and M.Q.Huang,Phys.Rev.D 80(2009)056004;J.R.Zhang and M.Q.Huang,Commun.Theor.Phys.54(2010)1075;Z.G.Wang,Phys.Lett.B 690(2010)403;J.R.Zhang,M.Zhong,and M.Q.Huang,Phys.Lett.B 704(2011)312;J.M.Dias,F.S.Navarra,M.Nielsen,and C.M.Zanetti,Phys.Rev.D 88(2013)016004;W.Chen,H.Y.Jin,R.T.Kleiv,et al.,Phys.Rev.D 88(2013)045027;C.F.Qiao and L.Tang,Eur.Phys.J.C 74(2014)2810;W.Chen,T.G.Steele,and S.L.Zhu,Universe 2(2014)13;W.Chen,T.G.Steele,H.X.Chen,and S.L.Zhu,Eur.Phys.J.C 75(2015)358;Z.G.Wang,Eur.Phys.J.C 76(2016)70;Z.G.Wang and T.Huang,Eur.Phys.J.C 76(2016)43.

    [3]Z.G.Wang and T.Huang,Phys.Rev.D 89(2014)054019;Z.G.Wang,Eur.Phys.J.C 74(2014)2874;Z.G.Wang,Commun.Theor.Phys.63(2015)466;Z.G.Wang and Y.F.Tian,Int.J.Mod.Phys.A 30(2015)1550004.

    [4]Z.G.Wang and T.Huang,Eur.Phys.J.C 74(2014)2891;Z.G.Wang,Eur.Phys.J.C 74(2014)2963.

    [5]M.A.Shifman,A.I.Vainshtein,and V.I.Zakharov,Nucl.Phys.B 147(1979)385.

    [6]L.J.Reinders,H.Rubinstein,and S.Yazaki,Phys.Rept.127(1985)1.

    [7]A.De Rujula,H.Georgi,and S.L.Glashow,Phys.Rev.D 12(1975)147;T.A.DeGrand,R.L.Ja ff e,K.Johnson,and J.E.Kiskis,Phys.Rev.D 12(1975)2060.

    [8]Z.G.Wang,Eur.Phys.J.C 71(2011)1524;R.T.Kleiv,T.G.Steele,A.Zhang,and L.Blokland,Phys.Rev.D 87(2013)125018.

    [9]Z.G.Wang,Commun.Theor.Phys.59(2013)451.

    [10]Z.G.Wang,Eur.Phys.J.C 62(2009)375;Z.G.Wang,Phys.Rev.D 79(2009)094027;Z.G.Wang,Eur.Phys.J.C 67(2010)411.

    [11]P.Colangelo and A.Khodjamirian,arXiv:hep-ph/001 0175.

    [12]Z.G.Wang,Eur.Phys.J.C 76(2016)387.

    [13]Z.G.Wang,Commun.Theor.Phys.63(2015)325.

    [14]L.Maiani,F.Piccinini,A.D.Polosa,and V.Riquer,Phys.Rev.D 89(2014)114010.

    [15]M.Nielsen and F.S.Navarra,Mod.Phys.Lett.A 29(2014)1430005.

    [16]Z.G.Wang,Eur.Phys.J.C 77(2017)78.

    猜你喜歡
    王志剛
    Don’t Be Addicted To The Internet
    A Loving Brother
    Two Stories
    What Should The Man Do
    Tom Broke A Plate Or A Watch
    王志剛運(yùn)用烏梅丸經(jīng)驗
    王志剛教授簡介
    王志剛教授簡介
    Scalar or Vector Tetraquark State Candidate: Zc(4100)?
    Analysis of the Possible D(2317)and D?2460)Molecules with QCD Sum Rules?
    老熟女久久久| av福利片在线| 精品国内亚洲2022精品成人 | 国产欧美日韩一区二区三| 叶爱在线成人免费视频播放| 免费在线观看亚洲国产| 热re99久久国产66热| 国产一区二区三区视频了| 国产不卡av网站在线观看| 叶爱在线成人免费视频播放| 老司机午夜福利在线观看视频| 欧美最黄视频在线播放免费 | 亚洲三区欧美一区| 国产精品国产av在线观看| 满18在线观看网站| 大片电影免费在线观看免费| 久久久久国产精品人妻aⅴ院 | 高清在线国产一区| 少妇 在线观看| tube8黄色片| 亚洲人成77777在线视频| 波多野结衣一区麻豆| 成人18禁高潮啪啪吃奶动态图| 亚洲国产精品合色在线| 少妇被粗大的猛进出69影院| 18在线观看网站| 国产精品 欧美亚洲| 国产免费男女视频| 日韩 欧美 亚洲 中文字幕| 中文字幕人妻丝袜制服| 大码成人一级视频| 老熟妇乱子伦视频在线观看| 国产不卡av网站在线观看| 亚洲五月天丁香| 午夜成年电影在线免费观看| 国产亚洲精品久久久久久毛片 | 精品国内亚洲2022精品成人 | 亚洲精品自拍成人| 黑人欧美特级aaaaaa片| 国产视频一区二区在线看| 午夜福利乱码中文字幕| 国产成人精品久久二区二区91| 成人国语在线视频| 欧美不卡视频在线免费观看 | 亚洲七黄色美女视频| 首页视频小说图片口味搜索| 又黄又爽又免费观看的视频| 在线永久观看黄色视频| 久久九九热精品免费| 多毛熟女@视频| 欧美日韩av久久| 日韩 欧美 亚洲 中文字幕| 亚洲一码二码三码区别大吗| 99久久综合精品五月天人人| 欧美精品亚洲一区二区| 欧美黑人精品巨大| 男人的好看免费观看在线视频 | 精品少妇一区二区三区视频日本电影| 国产淫语在线视频| 亚洲av第一区精品v没综合| 视频在线观看一区二区三区| 亚洲国产中文字幕在线视频| 久久香蕉精品热| 免费在线观看完整版高清| 亚洲人成电影观看| 99精品在免费线老司机午夜| 婷婷精品国产亚洲av在线 | 老司机在亚洲福利影院| 亚洲成人国产一区在线观看| 香蕉国产在线看| 人人澡人人妻人| 丝袜在线中文字幕| 日韩三级视频一区二区三区| 精品无人区乱码1区二区| 亚洲成人手机| 热re99久久精品国产66热6| 丁香欧美五月| 亚洲九九香蕉| 波多野结衣一区麻豆| 窝窝影院91人妻| 12—13女人毛片做爰片一| 欧美日本中文国产一区发布| e午夜精品久久久久久久| 久久精品国产综合久久久| 久久久国产欧美日韩av| 电影成人av| 久久ye,这里只有精品| 一边摸一边做爽爽视频免费| 亚洲精品粉嫩美女一区| 精品久久久久久电影网| 日韩免费高清中文字幕av| 国产亚洲精品第一综合不卡| 久久亚洲真实| 伦理电影免费视频| 妹子高潮喷水视频| 久久中文字幕人妻熟女| 最新在线观看一区二区三区| 亚洲自偷自拍图片 自拍| 丁香欧美五月| 欧美精品一区二区免费开放| 亚洲成人手机| 国产av一区二区精品久久| 午夜福利在线观看吧| 亚洲欧洲精品一区二区精品久久久| 黑人巨大精品欧美一区二区mp4| 国产精品久久久人人做人人爽| 亚洲精品自拍成人| 男男h啪啪无遮挡| av中文乱码字幕在线| 91av网站免费观看| 国产aⅴ精品一区二区三区波| 一区二区三区激情视频| 精品久久久久久久毛片微露脸| 日本wwww免费看| 精品卡一卡二卡四卡免费| 亚洲国产毛片av蜜桃av| 免费人成视频x8x8入口观看| 啦啦啦视频在线资源免费观看| 国产深夜福利视频在线观看| 国产精品久久视频播放| 久久午夜综合久久蜜桃| 男女午夜视频在线观看| 一边摸一边抽搐一进一小说 | 香蕉丝袜av| av网站在线播放免费| 午夜激情av网站| 黄片小视频在线播放| 久久香蕉激情| 黑人操中国人逼视频| 亚洲国产毛片av蜜桃av| 高清毛片免费观看视频网站 | 亚洲欧美一区二区三区久久| 午夜福利一区二区在线看| 丝袜人妻中文字幕| 久久青草综合色| 乱人伦中国视频| 男女之事视频高清在线观看| 我的亚洲天堂| 日本五十路高清| 一夜夜www| 丰满人妻熟妇乱又伦精品不卡| 一区二区三区激情视频| 99国产综合亚洲精品| 婷婷丁香在线五月| 身体一侧抽搐| 91av网站免费观看| 人人妻人人添人人爽欧美一区卜| 欧美av亚洲av综合av国产av| 久久午夜亚洲精品久久| 91在线观看av| a级片在线免费高清观看视频| 中文字幕人妻熟女乱码| 老司机在亚洲福利影院| 成人亚洲精品一区在线观看| 色尼玛亚洲综合影院| 黄色 视频免费看| 大香蕉久久网| 成熟少妇高潮喷水视频| 一进一出抽搐gif免费好疼 | 熟女少妇亚洲综合色aaa.| 麻豆乱淫一区二区| 91成年电影在线观看| 久久草成人影院| 少妇 在线观看| 岛国毛片在线播放| 欧美另类亚洲清纯唯美| 丝袜在线中文字幕| 天天操日日干夜夜撸| 9色porny在线观看| 国产xxxxx性猛交| 一区二区三区精品91| 一级毛片精品| 久久亚洲精品不卡| 99热国产这里只有精品6| 不卡av一区二区三区| 国产欧美日韩一区二区三| 操出白浆在线播放| 变态另类成人亚洲欧美熟女 | 人妻 亚洲 视频| 久久性视频一级片| 成年人午夜在线观看视频| 在线免费观看的www视频| 精品无人区乱码1区二区| 亚洲色图av天堂| 免费在线观看完整版高清| 精品一区二区三区四区五区乱码| 建设人人有责人人尽责人人享有的| 黄色 视频免费看| www.999成人在线观看| 国产亚洲欧美98| 成年版毛片免费区| 露出奶头的视频| 热99久久久久精品小说推荐| 亚洲免费av在线视频| 一级黄色大片毛片| 亚洲九九香蕉| 日日夜夜操网爽| 国产在线观看jvid| 麻豆av在线久日| 欧美最黄视频在线播放免费 | 国产精品 欧美亚洲| 51午夜福利影视在线观看| 看片在线看免费视频| 亚洲精品在线观看二区| www.熟女人妻精品国产| 高清毛片免费观看视频网站 | 高清在线国产一区| 男女之事视频高清在线观看| 天堂中文最新版在线下载| 日韩视频一区二区在线观看| 极品少妇高潮喷水抽搐| 精品少妇一区二区三区视频日本电影| 香蕉久久夜色| 亚洲欧美日韩高清在线视频| 精品久久久久久电影网| 久久中文字幕一级| 欧美黑人欧美精品刺激| 精品久久久精品久久久| 色综合欧美亚洲国产小说| 美女高潮到喷水免费观看| 亚洲成人免费电影在线观看| 欧美人与性动交α欧美软件| 看片在线看免费视频| 在线观看免费高清a一片| 日本撒尿小便嘘嘘汇集6| 亚洲男人天堂网一区| 一进一出抽搐gif免费好疼 | 三上悠亚av全集在线观看| 精品视频人人做人人爽| 免费日韩欧美在线观看| 我的亚洲天堂| 亚洲精品乱久久久久久| 美女 人体艺术 gogo| 99热网站在线观看| 欧美亚洲 丝袜 人妻 在线| 欧美精品高潮呻吟av久久| 亚洲中文字幕日韩| 变态另类成人亚洲欧美熟女 | 怎么达到女性高潮| 18在线观看网站| 欧美精品高潮呻吟av久久| 日韩中文字幕欧美一区二区| 精品久久久久久久久久免费视频 | 高清欧美精品videossex| 黑人操中国人逼视频| 精品一区二区三区av网在线观看| www.精华液| 免费一级毛片在线播放高清视频 | 久久久久久免费高清国产稀缺| 国产精品98久久久久久宅男小说| 国产亚洲精品久久久久久毛片 | 天堂中文最新版在线下载| 国产精品自产拍在线观看55亚洲 | 欧美中文综合在线视频| 制服人妻中文乱码| 国产成人一区二区三区免费视频网站| av中文乱码字幕在线| 精品福利观看| 亚洲免费av在线视频| 一区二区三区精品91| 一级,二级,三级黄色视频| 俄罗斯特黄特色一大片| 日韩精品免费视频一区二区三区| 一级a爱视频在线免费观看| 女警被强在线播放| 国产又色又爽无遮挡免费看| 亚洲国产精品合色在线| 后天国语完整版免费观看| 亚洲色图av天堂| 成年女人毛片免费观看观看9 | 丝袜在线中文字幕| 日本a在线网址| 精品人妻1区二区| 国产亚洲精品一区二区www | 天天躁夜夜躁狠狠躁躁| 日韩制服丝袜自拍偷拍| 午夜福利视频在线观看免费| 女人高潮潮喷娇喘18禁视频| 大型黄色视频在线免费观看| 午夜影院日韩av| 国产一区在线观看成人免费| 久久精品熟女亚洲av麻豆精品| 巨乳人妻的诱惑在线观看| 成人免费观看视频高清| 久久九九热精品免费| 国产成人欧美在线观看 | 欧美av亚洲av综合av国产av| 日本精品一区二区三区蜜桃| 少妇裸体淫交视频免费看高清 | 一区二区三区国产精品乱码| 又紧又爽又黄一区二区| 久久国产精品男人的天堂亚洲| 十八禁网站免费在线| 亚洲五月天丁香| 在线观看免费午夜福利视频| 亚洲精品国产色婷婷电影| 国产精品国产高清国产av | 十八禁人妻一区二区| 两人在一起打扑克的视频| 成年女人毛片免费观看观看9 | 999精品在线视频| 欧美午夜高清在线| av有码第一页| 亚洲五月天丁香| 人妻久久中文字幕网| 日日摸夜夜添夜夜添小说| 国产99白浆流出| 国产视频一区二区在线看| 日韩免费av在线播放| 老司机靠b影院| 国产欧美日韩一区二区三| 久久久久久久精品吃奶| 两人在一起打扑克的视频| 少妇猛男粗大的猛烈进出视频| 亚洲欧美日韩另类电影网站| av中文乱码字幕在线| 叶爱在线成人免费视频播放| 十分钟在线观看高清视频www| 怎么达到女性高潮| av免费在线观看网站| avwww免费| 最新的欧美精品一区二区| 校园春色视频在线观看| 美女国产高潮福利片在线看| 欧美黑人精品巨大| 久久国产精品大桥未久av| 18禁裸乳无遮挡免费网站照片 | 麻豆av在线久日| 黄片播放在线免费| 亚洲av成人不卡在线观看播放网| 天堂中文最新版在线下载| 国内久久婷婷六月综合欲色啪| 国产亚洲一区二区精品| 国产三级黄色录像| 国产单亲对白刺激| 中文字幕高清在线视频| 变态另类成人亚洲欧美熟女 | 亚洲av日韩在线播放| av超薄肉色丝袜交足视频| 亚洲人成电影免费在线| 中出人妻视频一区二区| 黄色怎么调成土黄色| 高清欧美精品videossex| 国产精品一区二区精品视频观看| 精品国产超薄肉色丝袜足j| 亚洲三区欧美一区| 国产99白浆流出| 男人舔女人的私密视频| 精品一区二区三区视频在线观看免费 | 一区在线观看完整版| 久久亚洲真实| 久久中文字幕人妻熟女| 在线免费观看的www视频| 婷婷成人精品国产| 欧美日韩黄片免| 亚洲欧美色中文字幕在线| 老汉色av国产亚洲站长工具| 亚洲黑人精品在线| 一级片'在线观看视频| 午夜激情av网站| 他把我摸到了高潮在线观看| 免费看十八禁软件| 黄片播放在线免费| 超碰97精品在线观看| 精品人妻熟女毛片av久久网站| 在线观看免费日韩欧美大片| 国产成人影院久久av| 嫁个100分男人电影在线观看| 国产91精品成人一区二区三区| 日韩免费高清中文字幕av| 欧美乱码精品一区二区三区| 高潮久久久久久久久久久不卡| 日本wwww免费看| 校园春色视频在线观看| 老鸭窝网址在线观看| av一本久久久久| 亚洲五月色婷婷综合| a级片在线免费高清观看视频| 久99久视频精品免费| 久久精品国产综合久久久| 大型黄色视频在线免费观看| 男女免费视频国产| 狂野欧美激情性xxxx| 亚洲精品成人av观看孕妇| 亚洲熟妇熟女久久| 女人被狂操c到高潮| 美女国产高潮福利片在线看| 亚洲精品美女久久久久99蜜臀| 色综合欧美亚洲国产小说| 国产精品99久久99久久久不卡| 亚洲av美国av| 操美女的视频在线观看| 91精品国产国语对白视频| 婷婷精品国产亚洲av在线 | 精品国产乱子伦一区二区三区| 91成人精品电影| 最近最新中文字幕大全免费视频| 黄色丝袜av网址大全| 欧美日韩黄片免| 天堂中文最新版在线下载| 亚洲精品久久午夜乱码| 男女午夜视频在线观看| 国产欧美日韩一区二区三区在线| 精品国产亚洲在线| 天堂动漫精品| 大片电影免费在线观看免费| 热re99久久精品国产66热6| av天堂在线播放| 一区二区日韩欧美中文字幕| 19禁男女啪啪无遮挡网站| 亚洲九九香蕉| 1024视频免费在线观看| a级毛片在线看网站| 久9热在线精品视频| 女人精品久久久久毛片| www.精华液| 啦啦啦视频在线资源免费观看| 免费一级毛片在线播放高清视频 | 99国产精品一区二区蜜桃av | 夫妻午夜视频| 999精品在线视频| 久久人妻福利社区极品人妻图片| 国产精品 欧美亚洲| 日本五十路高清| 欧美乱妇无乱码| 日韩免费高清中文字幕av| 欧美老熟妇乱子伦牲交| 18禁黄网站禁片午夜丰满| 一边摸一边做爽爽视频免费| 日韩视频一区二区在线观看| 国内久久婷婷六月综合欲色啪| av天堂在线播放| 欧美乱妇无乱码| 99国产精品一区二区三区| 在线免费观看的www视频| 无人区码免费观看不卡| 国产精品1区2区在线观看. | 99久久国产精品久久久| 国产乱人伦免费视频| 五月开心婷婷网| 亚洲综合色网址| 精品国产亚洲在线| 国产伦人伦偷精品视频| 怎么达到女性高潮| 国产av一区二区精品久久| 黄色片一级片一级黄色片| 下体分泌物呈黄色| 叶爱在线成人免费视频播放| 自线自在国产av| 搡老熟女国产l中国老女人| 天堂俺去俺来也www色官网| 搡老岳熟女国产| 欧美激情极品国产一区二区三区| 桃红色精品国产亚洲av| 亚洲成国产人片在线观看| 91老司机精品| 嫩草影视91久久| 91国产中文字幕| 香蕉久久夜色| 欧美激情极品国产一区二区三区| 国产精品 欧美亚洲| 一级a爱片免费观看的视频| av超薄肉色丝袜交足视频| 亚洲av成人一区二区三| 久久天堂一区二区三区四区| 中出人妻视频一区二区| 久久精品国产a三级三级三级| 老鸭窝网址在线观看| 国产精品乱码一区二三区的特点 | 啦啦啦视频在线资源免费观看| 精品国产美女av久久久久小说| 久久草成人影院| 999精品在线视频| 亚洲av欧美aⅴ国产| 精品卡一卡二卡四卡免费| 人妻 亚洲 视频| bbb黄色大片| 欧美成人午夜精品| 国产精品 国内视频| 不卡av一区二区三区| 国产欧美亚洲国产| 黑人欧美特级aaaaaa片| 久久精品国产亚洲av香蕉五月 | 免费看十八禁软件| 亚洲精品av麻豆狂野| 亚洲精品久久成人aⅴ小说| 岛国毛片在线播放| a级毛片在线看网站| 精品欧美一区二区三区在线| 中文字幕制服av| 久久亚洲真实| 一级毛片女人18水好多| avwww免费| 777米奇影视久久| 精品人妻1区二区| 久久午夜亚洲精品久久| 精品福利观看| 午夜亚洲福利在线播放| 国产高清国产精品国产三级| 免费黄频网站在线观看国产| 99香蕉大伊视频| 女人被躁到高潮嗷嗷叫费观| 欧美黑人欧美精品刺激| 欧美日韩亚洲国产一区二区在线观看 | 丰满迷人的少妇在线观看| 国产成+人综合+亚洲专区| 国产日韩欧美亚洲二区| 国产av精品麻豆| 老司机午夜福利在线观看视频| 黄色毛片三级朝国网站| 中文亚洲av片在线观看爽 | 性少妇av在线| 亚洲av片天天在线观看| av线在线观看网站| 亚洲av电影在线进入| 精品国产一区二区久久| 日日夜夜操网爽| 少妇粗大呻吟视频| 露出奶头的视频| 99热网站在线观看| 天天躁日日躁夜夜躁夜夜| 纯流量卡能插随身wifi吗| 国产三级黄色录像| 大片电影免费在线观看免费| 久久国产精品影院| 精品人妻熟女毛片av久久网站| a在线观看视频网站| 在线观看免费视频日本深夜| 亚洲七黄色美女视频| 热99国产精品久久久久久7| 久久中文字幕人妻熟女| 国产激情欧美一区二区| 捣出白浆h1v1| 正在播放国产对白刺激| 精品国产美女av久久久久小说| 国产精品免费大片| 精品亚洲成a人片在线观看| 国产欧美日韩综合在线一区二区| 亚洲熟女毛片儿| 又大又爽又粗| 中文亚洲av片在线观看爽 | 国产精品99久久99久久久不卡| 国内毛片毛片毛片毛片毛片| 国产精品电影一区二区三区 | 美女扒开内裤让男人捅视频| 在线视频色国产色| 国产麻豆69| 新久久久久国产一级毛片| av片东京热男人的天堂| 无遮挡黄片免费观看| 久久久久久亚洲精品国产蜜桃av| 大型黄色视频在线免费观看| 国产极品粉嫩免费观看在线| 老熟妇仑乱视频hdxx| 精品熟女少妇八av免费久了| 精品一区二区三区视频在线观看免费 | 国产精品免费视频内射| 国产黄色免费在线视频| 麻豆乱淫一区二区| 中亚洲国语对白在线视频| 欧美日韩精品网址| 交换朋友夫妻互换小说| 手机成人av网站| 麻豆av在线久日| 黄网站色视频无遮挡免费观看| 亚洲五月天丁香| 欧美不卡视频在线免费观看 | 乱人伦中国视频| 久久这里只有精品19| 波多野结衣av一区二区av| 操美女的视频在线观看| 精品国产超薄肉色丝袜足j| 交换朋友夫妻互换小说| 国产精品乱码一区二三区的特点 | 在线播放国产精品三级| av天堂在线播放| 日本撒尿小便嘘嘘汇集6| 国产亚洲一区二区精品| 国内毛片毛片毛片毛片毛片| 搡老熟女国产l中国老女人| 天天添夜夜摸| 色婷婷久久久亚洲欧美| 日本a在线网址| 欧美日韩精品网址| 男人操女人黄网站| 三上悠亚av全集在线观看| 日韩有码中文字幕| 久久国产乱子伦精品免费另类| 中出人妻视频一区二区| 国产av一区二区精品久久| 啦啦啦视频在线资源免费观看| 国内毛片毛片毛片毛片毛片| 国产视频一区二区在线看| 一进一出抽搐动态| 一a级毛片在线观看| √禁漫天堂资源中文www| 久久久水蜜桃国产精品网| 韩国av一区二区三区四区| 1024视频免费在线观看| 老熟妇仑乱视频hdxx| 亚洲人成伊人成综合网2020| 十八禁高潮呻吟视频| 日韩欧美在线二视频 | 国产精品欧美亚洲77777| 人人妻人人爽人人添夜夜欢视频| xxx96com| 女性生殖器流出的白浆| 久久久久国产精品人妻aⅴ院 | 久久婷婷成人综合色麻豆| 首页视频小说图片口味搜索| 巨乳人妻的诱惑在线观看| 最新美女视频免费是黄的| 午夜福利,免费看| 一本综合久久免费| 男人的好看免费观看在线视频 |