Proton number fluctuation as a signal of the QCD critical end-point

We argue that the event-by-event fluctuation of the proton number is a meaningful and promising observable for the purpose of detecting the QCD critical end-point in heavy-ion collision experiments. The long range fluctuation of the order parameter induces a characteristic correlation between protons which can be measured. The proton fluctuation also manifests itself as anomalous enhancement of charge fluctuations near the end-point, which might be already seen in existing data.Comment: 4 pages, version accepted in PR

Jet evolution from weak to strong coupling

Recent studies, using the AdS/CFT correspondence, of the radiation produced by a decaying system or by an accelerated charge in the N=4 supersymmetric Yang-Mills theory, led to a striking result: the 'supergravity backreaction', which is supposed to describe the energy density at infinitely strong coupling, yields exactly the same result as at zero coupling, that is, it shows no trace of quantum broadening. We argue that this is not a real property of the radiation at strong coupling, but an artifact of the backreaction calculation, which is unable to faithfully capture the space-time distribution of the radiation. This becomes obvious in the case of a decaying system ('virtual photon'), for which the backreaction is tantamount to computing a three-point function in the conformal gauge theory, which is independent of the coupling since protected by symmetries. Whereas this non-renormalization property is specific to the conformal N=4 SYM theory, we argue that the failure of the three-point function to provide a local measurement is in fact generic: it holds in any field theory with non-trivial interactions. To properly study a localized distribution, one should rather compute a four-point function, as standard in deep inelastic scattering. We substantiate these considerations with studies of the radiation produced by the decay of a time-like photon at both weak and strong coupling. We show that by computing four-point functions, in perturbation theory at weak coupling and, respectively, from Witten diagrams at strong coupling, one can follow the quantum evolution and thus demonstrate the broadening of the energy distribution. This broadening is slow when the coupling is weak but it proceeds as fast as possible in the limit of a strong coupling.Comment: 49 pages, 6 figure

Hubungan Ekuilibrium Jangka Panjang antara Variabel Ekonomi Makro dan Return Saham

Penelitian ini bertujuan untuk menginvestigasi hubungan antara variabel makroekonomi dan return saham di Indonesia. Sampel terdiri dari 58 observasi dari data Bursa Efek Indonesia pada tahun 1990 hingga 2004. Penggunaan data tersebut dikarenakan pada tahun 1997 di Indonesia terdapat structural break pada data yang disebabkan oleh krisis ekonomi. Kontribusi dari penelitian ini adalah penggunaan pengujian akar unit Zivot-Andrews untuk mengakomodasi data structural break tersebut. Hasil analisis regresi yang dilakukan dengan menggunakan EngleGranger dan Gregory-Hansen untuk pengujian kointegrasi menunjukkan bahwa hanya variabel output dan nilai tukar yang mempengaruhi keseimbangan hubungan jangka panjang return saham. Hasil yang konsisten juga ditunjukkan oleh model koreksi kesalahan

Dai Sebagai Ulama Pewaris Para Nabi

Allah guides people through the presence of the messengers who served as a witness, to give glad tidings and warnings, the Caller of Allah, to teach the Qur'an and the wisdom and to be good role models for human beings. However, as the messenger was gone, the task of the apostles passed on to the scholars or preachers whose task is to invite people to the path of Allah. Therefore, the scholars and preachers, as the spearhead of the spread of Islam, need to know the tasks of the Prophet and also follow the example of the Prophet in carrying out the mandate Allah assigned to him. Allah memberikan petunjuk kepada manusia melalui kehadiran para rasul yang bertugas untuk menjadi saksi, memberikan kabar gembira dan peringatan, penyeru agama Allah, mengajarkan al-Qur'an dan hikmah serta menjadi suri tauladan yang baik bagi manusia. Namun, ketika rasul sudah tiada, maka tugas rasul tersebut diwariskan kepada para ulama atau dai yang bertugas untuk mengajak manusia kepada jalan Allah. Oleh karena itu, dai sebagai ujung tombak penyebaran Islam perlu mengetahui tugas-tugas para Nabi dan juga mencontoh Nabi dalam mengemban amanat Allah yang dibebankan kepadanya

Harmonisasi Kewenangan Pengurusan Izin Keramaian antara Kepolisian dan Pemerintah Kota Malang

Harmonisasi yang dilakukan oleh kepolisian dan badan pelayanan perizinan terpadu kota malang yaitu dengan cara koordinasi tetapi di haruskan dengan koordinasi yang jelas. hambatan yang muncul yaitu a).faktor koordinasi yang kurang berjalan dengan optimal dari Kepolisian dan Pemerintah Kota Malang. b). Faktor undang-undang yang masih kacau atau rancu. c). faktor kurangnya sosialisasi tentang pengurusan izin keramaian antara kepolisian dan pemerintah kota malang. d). adanya penyalagunaan wewenang. Upaya yang dilakukan dalam harmonisasi a). adanya MoU. b). merumuskan kembali peraturan yang di anggap rancu tentang izin keramaian. c). sosialisasi pengurusan izin keramaian di masyarakat. d). adanya pembinaan rutin di kedua instansi tentang izin keramaian umum.Kata kunci : Harmonisasi, izin keramaia

Aspects of the UV/IR correspondence : energy broadening and string fluctuations

We show that a source which radiates in the vacuum of the strongly coupled N=4 SYM theory produces an energy distribution which, in the supergravity approximation, has the same space-time pattern as the corresponding classical distribution: the radiation propagates at the speed of light without broadening. We illustrate this on the basis of several examples: a small perturbation propagating down a steady string, a massless particle falling into AdS_5, and the decay of a time-like wave-packet. A similar observation was made in Phys. Rev. D81 (2010) 126001 for the case of a rotating string. In all these cases, the absence of broadening is related to the fact that the energy backreaction on the boundary arises exclusively from the bulk perturbation at, or near, the boundary. This is so since bulk sources which propagate in AdS_5 at the speed of light do not generate any energy on the boundary. We interpret these features as an artifact of the supergravity approximation, which fails to encode quantum mechanical fluctuations that should be present even in the strong coupling limit. We argue that such fluctuations should enter the dual string theory as longitudinal string fluctuations, which are not suppressed at strong coupling. We heuristically estimate the effects of such fluctuations and argue that they restore the broadening of the radiation, in agreement with expectations from both quantum mechanics and the ultraviolet/infrared correspondence.Comment: 47 page

Parton picture for the strongly coupled SYM plasma

Deep inelastic scattering off the strongly coupled N=4 supersymmetric Yang-Mills plasma at finite temperature can be computed within the AdS/CFT correspondence, with results which are suggestive of a parton picture for the plasma. Via successive branchings, essentially all partons cascade down to very small values of the longitudinal momentum fraction x and to transverse momenta smaller than the saturation momentum Q_s\sim T/x. This scale Q_s controls the plasma interactions with a hard probe, in particular, the jet energy loss and its transverse momentum broadening.Comment: 4 pages, Talk given at Quark Matter 2008: 20th International Conference on Ultra-Relativistic Nucleus Nucleus Collisions (QM 2008), Jaipur, India, 4-10 Feb 200